WorldWideScience

Sample records for boron-added low-carbon steels

  1. Influence of boron on strain hardening behaviour and ductility of low carbon hot rolled steel

    International Nuclear Information System (INIS)

    Deva, Anjana; Jha, B.K.; Mishra, N.S.

    2011-01-01

    Highlights: → Unique feature of low strain hardening exponent (n) with high total elongation has been discussed in industrially produced low carbon boron containing steel. → n has been correlated with the micro structural changes occurring during deformation of steel. → This feature of low n and high % elongation has potential for higher cold reducibility. → The work is being reported for the first time on industrially produced low carbon boron containing steel. - Abstract: The beneficial effect of boron on mechanical properties of low carbon Al-killed steel has been reported in recent past. However, the effect of boron on strain hardening exponent (n) and ductility has not been fully understood. This aspect has been discussed in present work. The results of mill trials with reference to n and ductility with boron added steel are compared to those for commercial grade. The lowering of 'n' with increased total elongation in boron bearing steel has been related to the microstructural evolution as a result of boron addition.

  2. Plasticity of low carbon stainless steels

    International Nuclear Information System (INIS)

    Bulat, S.I.; Fel'dgandler, Eh.G.; Kareva, E.N.

    1975-01-01

    In the temperature range 800-1200 0 C and with strain rates of from 10 -3 to 3 s -1 , austenitic (000Kh18N12) and austenitic-ferrite (000Kh26N6) very low carbon stainless steels containing 0.02-0.03% C exhibit no higher resilience than corresponding ordinary steels containing 0.10-0.12% C. However, the plasticity of such steels (particularly two-phase steels) at 900-1100 0 C is appreciably inferior owing to the development of intergranular brittle fracture. Pressure treatment preceded by partial cooling of the surface to 850 0 C yields rolled and forged products with acceptable indices but is inconvenient technically. At the Zlatoustovsk and Ashin metallurgical plants successful tests have been performed involving the forging and rolling of such steels heated to 1280-1300 0 C without partial cooling; it was necessary to improve the killing conditions, correct the chemical composition (increasing the proportion of ferrite) and take measures against heat loss. (author)

  3. Low carbon manganese-nickel-niobium steel

    International Nuclear Information System (INIS)

    Heisterkamp, F.; Hulka, K.

    1983-11-01

    Experimental heats of a low carbon-manganese-0.5% nickel-0.15% niobium steel have been rolled to plates between 13.5 and 50 mm thickness and to a 16 mm hot strip. Various combinations of soaking temperatures form 1100 0 C to 1300 0 C and of finish rolling temperatures between 710 0 C and 930 0 C have been investigated. From mechanical properties obtained, one can conclude that the investigated steel composition provides very good properties e.g. for pipe steels X65 to X75. In particular, the toughness at low temperature is outstanding despite relaxed rolling conditions. Metalographic and special investigations such as electron microscopy, texture evaluation and chemical extraction, correlated with applied rolling schedules and the mechanical properties obtained resulted in a comprehensive understanding about the benefits of high niobium metallurgy combined with nickel addition. All practically applied welding processes generated mechanical properties, in particular toughness of the weldment, that meet arctic specifications.(Author) [pt

  4. corrosion response of low carbon steel in tropical road mud

    African Journals Online (AJOL)

    Dr Obe

    Corrosion Mitigation efforts using readily available anti- corrosion coatings to protect low carbon steel test coupons against the ... The following protective coating devices were effective: ..... 2 West, J.M (1986): Basic Corrosion and Oxidation,.

  5. Strength of low-carbon rotor steel

    International Nuclear Information System (INIS)

    Voropaev, V.I.; Filimonov, O.V.; Borisov, I.A.

    1988-01-01

    The results of studying the effect of chemical composition and thermal treatment regimes on the structural strength of steels of the 25KhN3MFA type are presented. It is shown that alloying with niobium from 0.01 to 0.08% steels with the increased nickel content (4.2-4.5%) contributes to the increase of structural strength and reduction of semibrittleness temperature. To obtain high values of strength and plastic properties cooling with the rate of 10 3 -10 5 K/hr is recommended

  6. intercritical heat treatments effects on low carbon steels quenched

    African Journals Online (AJOL)

    DR B. A. EZEKOYE

    Department of Physics and Astronomy, University of Nigeria, Nsukka. 2. E-mail: benjamin.ezekoye@unn.edu.ng; bezekoye@yahoo.com. ABSTRACT. Six low carbon steels containing carbon in the range 0.13-0.18wt%C were studied after intercritical quenching, intercritical quenching with low temperature tempering, ...

  7. Oxidation of ultra low carbon and silicon bearing steels

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Lucia [CTM - Technologic Centre, Materials Technology Area, Manresa, Barcelona (Spain)], E-mail: lucia.suarez@ctm.com.es; Rodriguez-Calvillo, Pablo [CTM - Technologic Centre, Materials Technology Area, Manresa, Barcelona (Spain)], E-mail: pablo.rodriguez@ctm.com.es; Houbaert, Yvan [Department of Materials Science and Engineering, University of Ghent (Belgium)], E-mail: Yvan.Houbaert@UGent.be; Colas, Rafael [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico)], E-mail: rcolas@mail.uanl.mx

    2010-06-15

    Oxidation tests were carried out in samples from an ultra low carbon and two silicon bearing steels to determine the distribution and morphology of the oxide species present. The ultra low carbon steel was oxidized for short periods of time within a chamber designed to obtain thin oxide layers by controlling the atmosphere, and for longer times in an electric furnace; the silicon steels were reheated only in the electric furnace. The chamber was constructed to study the behaviour encountered during the short period of time between descaling and rolling in modern continuous mills. It was found that the oxide layers formed on the samples reheated in the electric furnace were made of different oxide species. The specimens treated in the chamber had layers made almost exclusively of wustite. Selected oxide samples were studied by scanning electron microscopy to obtain electron backscattered diffraction patterns, which were used to identify the oxide species in the layer.

  8. Mixed structures in continuously cooled low-carbon automotive steels

    International Nuclear Information System (INIS)

    Khalid, F.A.; Edmonds, D.V.

    1993-01-01

    Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.)

  9. Ultra low carbon bainitic (ULCB) steels after quenching and tempering

    International Nuclear Information System (INIS)

    Lis, A.K.; Lis, J.; Kolan, C.; Jeziorski, L.

    1998-01-01

    The mechanical and Charpy V impact strength properties of new advanced ultra low carbon bainitic (ULBC) steels after water quenching and tempering (WQT) have been investigated. Their chemical compositions are given. The nine continuous cooling transformation diagrams (CCT) of the new ULCB steel grades have been established. The CCT diagrams for ULCB N i steels containing 9% Ni - grade 10N9 and 5% Ni - grade HN5MVNb are given. The comparison between CCT diagrams of 3.5%Ni + 1.5%Cu containing steels grade HSLA 100 and HN3MCu is shown. The effect of the increase in carbon and titanium contents in the chemical composition of ULCB M n steels 04G3Ti, 06G3Ti and 09G3Ti on the kinetics of phase transformations during continuous cooling is presented by the shifting CCT diagrams. The Charpy V impact strength and brittle fracture occurence curves are shown. The effect of tempering temperature on tensile properties of WQT HN3MCu steel is shown and Charpy V impact strength curves after different tempering conditions are shown. The optimum tempering temperatures region of HN3MCu steel for high Charpy V impact toughness at law temperatures - 80 o C(193 K) and -120 o C(153 K) is estimated. The effect of tempering temperature on mechanical properties of HN5MVNb steel is given. The low temperature impact Charpy V toughness of HN5MVNb steel is shown. The optimum range of tempering temperature during 1 hour for high toughness of WQT HN5MVNb steel is given. HN3MCu and HN5MVNb steels after WQT have high yield strength YS≥690 MPa and high Charpy V impact toughness KV≥80 J at -100 o C (173K) and KCV≥50 J/cm 2 at - 120 o C (153K) so they may be used for cryogenic applications

  10. Plasticity of low carbon steel in a hot state

    Energy Technology Data Exchange (ETDEWEB)

    Konovalov, V P; Rizol' , A I; Shram, N N [Ural' skij Nauchno-Issledovatel' skij Inst. Chernykh Metallov, Sverdlovsk (USSR)

    1977-07-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed.

  11. Plasticity of low carbon steel in a hot state

    International Nuclear Information System (INIS)

    Konovalov, V.P.; Rizol', A.I.; Shram, N.N.

    1977-01-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed

  12. Grain Refinement of Low Carbon Martensitic Steel by Heat Treatment

    Directory of Open Access Journals (Sweden)

    N. V. Kolebina

    2015-01-01

    Full Text Available The low-carbon steels have good corrosion and technological properties. Hot deformation is the main operation in manufacturing the parts from these steels. So one of the important properties of the material is a property of plasticity. The grain size significantly influences on the ductility properties of steel. The grain size of steel depends on the chemical composition of the crystallization process, heat treatment, and steel machining. There are plenty methods to have grain refinement. However, taking into account the large size of the blanks for the hydro turbine parts, the thermal cycling is an advanced method of the grain refinement adaptable to streamlined production. This work experimentally studies the heat treatment influence on the microstructure of the low-carbon 01X13N04 alloy steel and proposes the optimal regime of the heat treatment to provide a significantly reduced grain size. L.M. Kleiner, N.P. Melnikov and I.N. Bogachyova’s works focused both on the microstructure of these steels and on the influence of its parameters on the mechanical properties. The paper focuses mainly on defining an optimal regime of the heat treatment for grain refinement. The phase composition of steel and temperature of phase transformation were defined by the theoretical analysis. The dilatometric experiment was done to determine the precise temperature of the phase transformations. The analysis and comparison of the experimental data with theoretical data and earlier studies have shown that the initial sample has residual stress and chemical heterogeneity. The influence of the heat treatment on the grain size was studied in detail. It is found that at temperatures above 950 ° C there is a high grain growth. It is determined that the optimal number of cycles is two. The postincreasing number of cycles does not cause further reducing grain size because of the accumulative recrystallization process. Based on the results obtained, the thermal cycling

  13. Microstructures and mechanical properties of duplex low carbon steel

    Science.gov (United States)

    Alfirano; Eben, U. S.; Hidayat, M.

    2018-04-01

    The microstructures behavior of duplex cold-rolled low carbon steel for automotive applications has been investigated. Intercritical annealing treatment is commonly used to develop a duplex low carbon steel containing ferrite and martensite. To get a duplex phase ferrite and martensite, the specimens were heated at inter-critical annealing temperature of 775°C - 825°C, for heating time up to 20 minutes, followed by water-quenched. The hardness of specimens was studied. The optical microscopy was used to analyze the microstructures. The optimal annealing conditions (martensite volume fraction approaching 20%) at 775°C with a heating time of 10 minutes was achieved. The highest hardness value was obtained in cold-rolled specimens of 41% in size reduction for intercritical annealing temperature of 825°C. In this condition, the hardness value was 373 HVN. The correlation between intercritical annealing temperature and time can be expressed in the transformation kinetics as fγ/fe = 1-exp(-Ktn) wherein K and n are grain growth rate constant and Avrami’s exponent, respectively. From experiment, the value of K = 0.15 and n = 0.461. Using the relationship between temperatures and heating time, activation energy (Q) can be calculated that is 267 kJ/mol.

  14. Kinetics of electrochemical boriding of low carbon steel

    International Nuclear Information System (INIS)

    Kartal, G.; Eryilmaz, O.L.; Krumdick, G.; Erdemir, A.; Timur, S.

    2011-01-01

    In this study, the growth kinetics of the boride layers forming on low carbon steel substrates was investigated during electrochemical boriding which was performed at a constant current density of 200 mA/cm 2 in a borax based electrolyte at temperatures ranging from 1123 K to 1273 K for periods of 5-120 min. After boriding, the presence of both FeB and Fe 2 B phases were confirmed by the X-ray diffraction method. Cross-sectional microscopy revealed a very dense and thick morphology for both boride phases. Micro hardness testing of the borided steel samples showed a significant increase in the hardness of the borided surfaces (i.e., up to (1700 ± 200) HV), while the hardness of un-borided steel samples was approximately (200 ± 20) HV. Systematic studies over a wide range of boriding time and temperature confirmed that the rate of the boride layer formation is strongly dependent on boriding duration and has a parabolic character. The activation energy of boride layer growth for electrochemical boriding was determined as (172.75 ± 8.6) kJ/mol.

  15. Characterization of D2 tool steel friction surfaced coatings over low carbon steel

    International Nuclear Information System (INIS)

    Sekharbabu, R.; Rafi, H. Khalid; Rao, K. Prasad

    2013-01-01

    Highlights: • Solid state coating by friction surfacing method. • D2 tool steel is coated over relatively softer low carbon steel. • Defect free interface between tool steel coating and low carbon steel substrate. • D2 coatings exhibited higher hardness and good wear resistance. • Highly refined martensitic microstructure in the coating. - Abstract: In this work D2 tool steel coating is produced over a low carbon steel substrate using friction surfacing process. The process parameters are optimized to get a defect free coating. Microstructural characterization is carried out using optical microscopy, scanning electron microscopy and X-ray diffraction. Infrared thermography is used to measure the thermal profile during friction surfacing of D2 steel. Wear performance of the coating is studied using Pin-on-Disk wear tests. A lower rotational speed of the consumable rod and higher translational speed of the substrate is found to result in thinner coatings. Friction surfaced D2 steel coating showed fine-grained martensitic microstructure compared to the as-received consumable rod which showed predominantly ferrite microstructure. Refinement of carbides in the coating is observed due to the stirring action of the process. The infrared thermography studies showed the peak temperature attained by the D2 coating to be about 1200 °C. The combined effect of martensitic microstructure and refined carbides resulted in higher hardness and wear resistance of the coating

  16. Investigation of the pitting corrosion of low carbon steel containers

    International Nuclear Information System (INIS)

    Mughabghab, S.F.; Sullivan, T.M.

    1988-01-01

    The present study was undertaken because the prediction of the degradation rate of low carbon steel contains over long time frames is one of the crucial elements in the development of a source term model for low-level shallow land burial. The principal data base considered is that of the NBS corrosion measurements of ferrous materials buried in the ground for periods of up to 18 years. In this investigation, the maximum penetration in mils, hm, due to pitting corrosion was found to conform closely to the relation h m = kt n where it is the exposure time of the sample in years, κ is the pitting parameter in mil/(years) n , and n > O is a parameter related to the aeration property of the soil. The central objective of the present investigation is the determination of the dependence of the pitting parameters κ and n on the soil properties. The result of a detailed linear correlation analysis of κ on one hand, the pH value and the resistivity of the soil on the other hand revealed that κ is principally influenced by the pH value of the soil. The resistivity of the soil is found to play a minor role

  17. Effect of Cr and Mo on strain ageing behaviour of low carbon steel

    International Nuclear Information System (INIS)

    Pereloma, E.V.; Bata, V.; Scott, R.I.; Smith, R.M.

    2010-01-01

    This work explores the effects of Cr (0.26-0.74 wt%) and Mo (0.09-0.3 wt%) additions on the kinetics of strain ageing process in low carbon steel. The strain ageing behaviour of the steels was investigated by using tensile tests and transmission electron microscopy. The results have shown that Mo-alloyed steels undergo the same four stages of ageing as unalloyed low carbon steel, whereas Cr-alloyed steels exhibit only three stages of ageing. At the same time, the addition of Mo accelerates the ageing response, while alloying with Cr reduces the rate of strain ageing by ∼3 times in comparison with non-alloyed low carbon steel. It especially delays the offset of Stage III. This is explained by the reduction of carbon content in ferrite due to the enrichment of cementite with Cr leading to the reduction of its equilibrium solubility in ferrite.

  18. Effect of Cr and Mo on strain ageing behaviour of low carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Pereloma, E.V., E-mail: elenap@uow.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 (Australia); Bata, V. [Department of Materials Engineering, Monash University (Australia); Scott, R.I.; Smith, R.M. [BlueScope Steel Limited, Port Kembla (Australia)

    2010-04-25

    This work explores the effects of Cr (0.26-0.74 wt%) and Mo (0.09-0.3 wt%) additions on the kinetics of strain ageing process in low carbon steel. The strain ageing behaviour of the steels was investigated by using tensile tests and transmission electron microscopy. The results have shown that Mo-alloyed steels undergo the same four stages of ageing as unalloyed low carbon steel, whereas Cr-alloyed steels exhibit only three stages of ageing. At the same time, the addition of Mo accelerates the ageing response, while alloying with Cr reduces the rate of strain ageing by {approx}3 times in comparison with non-alloyed low carbon steel. It especially delays the offset of Stage III. This is explained by the reduction of carbon content in ferrite due to the enrichment of cementite with Cr leading to the reduction of its equilibrium solubility in ferrite.

  19. Ultra-Low Carbon Bainitic Steels for Heavy Plate Applications

    Science.gov (United States)

    1990-12-01

    these steels. The CCT diagrams 7 of steels typical of the HY grades indicate that the nose of the proeutectoid ferrite/pearlite reactions is located...austenite, carbides, and martensite. An example of the type of CCT diagram for one of the steels used in this investigation is presented in Figure 12...introduce a "bay" of unstable austenite which acts to separate the ferrite "nose" from the bainite/martensite regions on TTT or CCT diagrams , see Figure

  20. Stress state evaluation in low carbon and TRIP steels by magnetic permeability

    International Nuclear Information System (INIS)

    Kouli, M.-E.; Giannakis, M

    2016-01-01

    Magnetic permeability is an indicative factor for the steel health monitoring. The measurements of magnetic permeability lead to the evaluation of the stress state of any ferromagnetic steel. The magnetic permeability measurements were conducted on low carbon and TRIP steel samples, which were subjected to both tensile and compressive stresses. The results indicated a direct correlation of the magnetic permeability with the mechanical properties, the stress state and the microstructural features of the examined samples. (paper)

  1. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    OpenAIRE

    Mejía, Ignacio; Bedolla Jacuinde, Arnoldo; Maldonado, Cuauhtémoc; Cabrera Marrero, José M.

    2011-01-01

    The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 ◦C) at a constant true strain rate of 0.001 s−1. Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless,...

  2. Nondestructive evaluation of low carbon steel by magnetic adaptive testing

    Czech Academy of Sciences Publication Activity Database

    Vértesy, G.; Tomáš, Ivan; Kobayashi, S.

    2010-01-01

    Roč. 25, č. 2 (2010), s. 125-132 ISSN 1058-9759 R&D Projects: GA ČR GA102/06/0866; GA AV ČR 1QS100100508 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic NDE * magnetic adaptive testing * steel * magnetic hysteresis Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.771, year: 2010

  3. Effect of Mo Content on Microstructure and Property of Low-Carbon Bainitic Steels

    Directory of Open Access Journals (Sweden)

    Haijiang Hu

    2016-07-01

    Full Text Available In this work, three low-carbon bainitic steels, with different Mo contents, were designed to investigate the effects of Mo addition on microstructure and mechanical properties. Two-step cooling, i.e., initial accelerated cooling and subsequent slow cooling, was used to obtain the desired bainite microstructure. The results show that the product of strength and elongation first increases and then shows no significant change with increasing Mo. Compared with Mo-free steel, bainite in the Mo-containing steel tends to have a lath-like morphology due to a decrease in the bainitic transformation temperature. More martensite transformation occurs with the increasing Mo, resulting in greater hardness of the steel. Both the strength and elongation of the steel can be enhanced by Mo addition; however, the elongation may decrease with a further increase in Mo. From a practical viewpoint, the content of Mo could be ~0.14 wt. % for the composition design of low-carbon bainitic steels in the present work. To be noted, an optimal scheme may need to consider other situations such as the role of sheet thickness, toughness behavior and so on, which could require changes in the chemistry. Nevertheless, these results provide a reference for the composition design and processing method of low-carbon bainitic steels.

  4. Crystallographic features of lath martensite in low-carbon steel

    International Nuclear Information System (INIS)

    Kitahara, Hiromoto; Ueji, Rintaro; Tsuji, Nobuhiro; Minamino, Yoritoshi

    2006-01-01

    Electron backscattering diffraction with field-emission scanning electron microscopy was used to analyze crystallographically the lath martensite structure in a 0.20% carbon steel. The crystallographic features of the lath martensite structure, of the order of the prior austenite grain size or larger, were clarified. Although the orientations of the martensite crystals were scattered around the ideal variant orientations, the martensite in this steel maintained the Kurdjumov-Sachs (K-S) orientation relationship. The procedures of the crystallographic analysis of the martensite (ferrite) phase with the K-S orientation relationship were explained in detail. Variant analysis showed that all 24 possible variants did not necessarily appear within a single prior austenite grain and that all six variants did not necessarily appear within each packet. Specific combinations of two variants appeared within local regions (sub-blocks), indicating a strict rule for variant selection. Prior austenite grain boundaries and most of the packet boundaries were clearly recognized. However, it was difficult to determine the block boundaries within the sub-blocks

  5. Yttrium implantation effects on extra low carbon steel and pure iron

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H. [Clermont-Ferrand-2 Univ., Le Puy en Velay (France). Lab. Vellave d`Elaboration; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Advanced Materials, Joint Research Center, The European Commission, 21020, Ispra (Vatican City State, Holy See) (Italy); Josse-Courty, C. [Laboratoire de Recherche sur la Reactivite des Solides, UMR 56-13 CNRS, UFR Sciences et Techniques, 9 Avenue A. Savary, B.P. 400, 21011, Dijon Cedex (France)

    1999-05-25

    Extra low carbon steel and pure electrolytic iron samples were yttrium implanted using ion implantation technique. Compositions and structures of pure iron and steel samples were investigated before and after yttrium implantation by several analytical and structural techniques (RBS, SIMS, RHEED and XRD) to observe the yttrium implantation depth profiles in the samples. This paper shows the different effects of yttrium implantations (compositions and structures) according to the implanted sample nature. (orig.) 23 refs.

  6. Stochastic approach to pitting-corrosion-extreme modelling in low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado 10400, La Habana (Cuba); Caleyo, F. [Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)], E-mail: fcaleyo@gmail.com; Rivas, D.; Hallen, J.M. [Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

    2010-03-15

    A stochastic model previously developed by the authors using Markov chains has been improved in the light of new experimental evidence. The new model has been successfully applied to reproduce the time evolution of extreme pitting corrosion depths in low-carbon steel. The model is shown to provide a better physical understanding of the pitting process.

  7. Stochastic approach to pitting-corrosion-extreme modelling in low-carbon steel

    International Nuclear Information System (INIS)

    Valor, A.; Caleyo, F.; Rivas, D.; Hallen, J.M.

    2010-01-01

    A stochastic model previously developed by the authors using Markov chains has been improved in the light of new experimental evidence. The new model has been successfully applied to reproduce the time evolution of extreme pitting corrosion depths in low-carbon steel. The model is shown to provide a better physical understanding of the pitting process.

  8. Electrochemical Performance of Low-Carbon Steel in Alkaline Model Solutions Containing Hybrid Aggregates

    NARCIS (Netherlands)

    Koleva, D.A.; Hu, J.; De Wit, J.H.W.; Boshkov, N.; Radeva, T.; Milkova, V.; Van Breugel, K.

    2010-01-01

    This work reports on the electrochemical performance of low-carbon steel electrodes in model alkaline solutions in the presence of 4.9.10-4 g/l hybrid aggregates i.e. cement extract, containing PDADMAC (poly (diallyl, dimethyl ammonium chloride) / PAA (Poly (acrylic acid)/ PDADMAC over a CaO core.

  9. Numerical predictions of dry oxidation of iron and low-carbon steel at moderately elevated temperatures

    International Nuclear Information System (INIS)

    Henshall, G.A.

    1996-11-01

    Wrought and cast low-carbon steel are candidate materials for the thick (e.g. 10 cm) outer barrier of nuclear waste packages being considered for use in the potential geological repository at Yucca Mountain. Dry oxidation is possible at the moderately elevated temperatures expected at the container surface (323-533 K or 50-260 C). Numerical predictions of dry oxidation damage were made based on experimental data for iron and low-carbon steel and parabolic oxidation theory. The Forward Euler method was implemented to integrate the parabolic rate law for arbitrary, complex temperature histories. Assuming growth of a defect-free, adherent oxide, the surface penetration of a low-carbon steel barrier following 5000 years of exposure to a severe, but repository-relevant, temperature history is predicted to be only about 0.127 mm, less than 0.13% of the expected container thickness of 10 cm. Allowing the oxide to spall upon reaching a critical thickness increases the predicted metal penetration values, but degradation is still computed to be negligible. Thus, dry oxidation is not expected to significantly degrade the performance of thick, corrosion allowance barriers constructed of low-carbon steel

  10. Corrosion Behaviour of Nickel Plated Low Carbon Steel in Tomato Fluid

    Directory of Open Access Journals (Sweden)

    Oluleke OLUWOLE

    2010-12-01

    Full Text Available This research work investigated the corrosion resistance of nickel plated low carbon steel in tomato fluid. It simulated the effect of continuous use of the material in a tomato environment where corrosion products are left in place. Low carbon steel samples were nickel electroplated at 4V for 20, 25, 30 and 35 mins using Watts solution.The plated samples were then subjected to tomato fluid environment for for 30 days. The electrode potentials mV (SCE were measured every day. Weight loss was determined at intervals of 5 days for the duration of the exposure period. The result showed corrosion attack on the nickel- plated steel, the severity decreasing with the increasing weight of nickel coating on substrate. The result showed that thinly plated low carbon steel generally did not have any advantage over unplated steel. The pH of the tomato solution which initially was acidic was observed to progress to neutrality after 4 days and then became alkaline at the end of the thirty days test (because of corrosion product contamination of the tomatocontributing to the reduced corrosion rates in the plated samples after 10 days. Un-plated steel was found to be unsuitable for the fabrication of tomato processing machinery without some form of surface treatment - thick nickel plating is suitable as a protective coating in this environment.

  11. Manganese partitioning in low carbon manganese steel during annealing

    International Nuclear Information System (INIS)

    Lis, J.; Lis, A.; Kolan, C.

    2008-01-01

    For 6Mn16 steel experimental soft annealing at 625 deg. C for periods from 1 h to 60 h and modeling with Thermo-Calc were performed to estimate the partitioning of alloying elements, in particular Mn, between ferrite, cementite and austenite. Using transmission electron microscopy and X-ray analysis it was established that the increase of Mn concentration in carbides to a level 7%-11.2% caused a local decrease of the Ac 1 temperature and led to the presence of austenite around the carbides. Thus, after cooling, small bainite-martensite or bainite-martensite-retained austenite (BM-A) islands were observed. A dispersion of carbides and a coarsening process were observed. The measured amount of Mn in the carbides was in good agreement with theoretical predictions

  12. Effect of High-Temperature Thermomechanical Treatment on the Brittle Fracture of Low-Carbon Steel

    Science.gov (United States)

    Smirnov, M. A.; Pyshmintsev, I. Yu.; Varnak, O. V.; Mal'tseva, A. N.

    2018-02-01

    The effect of high-temperature thermomechanical treatment (HTMT) on the brittleness connected with deformation-induced aging and on the reversible temper brittleness of a low-carbon tube steel with a ferrite-bainite structure has been studied. When conducting an HTMT of a low-alloy steel, changes should be taken into account in the amount of ferrite in its structure and relationships between the volume fractions of the lath and the acicular bainite. It has been established that steel subjected to HTMT undergoes transcrystalline embrittlement upon deformation aging. At the same time, HTMT, which suppresses intercrystalline fracture, leads to a weakening of the development of reversible temper brittleness.

  13. Ferrite morphology and residual phases in continuously cooled low carbon steels

    International Nuclear Information System (INIS)

    Dunne, D.P.

    1999-01-01

    Although much research has been conducted on the isothermal transformation products of medium to high carbon hardenable steels, relatively little has been reported for transformation of low carbon structural steels under continuous cooling conditions. The trend towards reduced carbon levels (less than about 0.1 wt% C) has been driven by demands for formability and weldability, challenging steel designers to maintain strength by microalloying and/or thermomechanical controlled processing. Although control of the ferritic products formed in low carbon steels after hot rolling, normalising and welding is essential in order to ensure adequate strength and toughness, understanding of the microstructures formed on continuous cooling is still limited. In addition, transformation mechanisms remain controversial because of polarisation of researchers into groups championing diffusional and displacive theories for the transformation of austenite over a wide range of cooling rates. The present review compares and draws together the main ferrite classification schemes, and discusses some critical issues on kinetics and mechanisms, in an attempt to rationalise the effects of cooling rate, prior austenite structure and composition on the resulting ferrite structure and its mechanical properties. It is concluded that with increasing cooling rate the ferritic product becomes finer, more plate-like, more dislocated, more carbon supersaturated, more likely to be formed by a displacive mechanism, harder and stronger. Other conclusions are that: (i) 'bainitic ferrite', which is a pervasive form of ferrite in continuously cooled low carbon steels, is different from the conventional upper and lower bainites observed in higher carbon steels, insofar as the co-product 'phase' is typically martensite-austenite islands rather than cementite; and (ii) low carbon bainite rather than martensite is the dominant product at typical fast cooling rates (<500K/s) associated with commercial

  14. The hot working characteristics of a boron bearing and a conventional low carbon steel

    International Nuclear Information System (INIS)

    Stumpf, Waldo; Banks, Kevin

    2006-01-01

    Constitutive hot working constants were determined for an 11 ppm boron low carbon strip steel and compared from 875 to 1140 deg. C and strain rates of 0.001-2.5 s -1 to a high nitrogen low carbon strip steel. The boron steel showed a different hot working behaviour than the conventional steel with the steady state flow stress about 50-60% higher, the peak strain more than 50% higher and the eventual ferrite grain size about 40% smaller, if compared at the same temperature compensated strain rates or Z values. This difference persisted where the soaking temperature before compression was varied between 1140 and 1250 deg. C, proving that undissolved AlN in the boron-bearing steel was not responsible. With systematically varied linear cooling rates after hot working, the final ferrite grain size in the boron steel is finer and is independent of the two Z values applied during hot working. Retarded softening by dynamic recrystallisation during hot working in the boron containing steel is probably caused by boron solute drag of moving grain boundaries

  15. The study of the corrosion protection of the low-carbon steel using film-products

    International Nuclear Information System (INIS)

    Aiancului, L.; Millet, Jean-Pierre

    2001-01-01

    The paper reports studies on the efficiency of the film-inhibitors that covered low-carbon steel placed in a humid medium, and also, the optimization of the working conditions to improve the resistance to corrosion. The analyzes were done in the Industrial Physical - Chemical Laboratories of INSA - Lyon by electrochemical stationary techniques. The experimental device was a potentiometer of type EGG PAR (Princeton Applied Research). It was connected with a computer and three potential electrodes introduced in a cell with NaCl 30 g/l solution to acquire the data and to process the information. The film-products used were organic hydrosoluble polymers with diphosphonic 'heads' that permit a very good absorption at the metallic surface. This research is used to protect the installations of low-carbon steel against the atmospheric and high temperature corrosion. (authors)

  16. Effect of Boron on the Hot Ductility of Resulfurized Low-Carbon Free-Cutting Steel

    Science.gov (United States)

    Liu, Hai-tao; Chen, Wei-qing

    2015-09-01

    The hot ductility of resulfurized low-carbon free-cutting steel with boron additives is studied in the temperature range 850 - 1200°C with the help of a Gleeble-1500 thermomechanical simulator. The introduction of boron increases hot ductility, especially at 900 - 1050°C. In the single-phase austenitic region, this effect is caused by segregation of boron over grain boundaries, acceleration of dynamic recrystallization, and solid-solution softening of deformed austenite.

  17. Microstructure and mechanical properties of internal crack healing in a low carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Ruishan [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing 100084 (China); Ma, Qingxian, E-mail: maqxdme@mail.tsinghua.edu.cn [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing 100084 (China); Li, Weiqi [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2016-04-26

    The behavior of internal crack healing in a low carbon steel at elevated temperatures was investigated. The internal cracks were introduced into low carbon steel samples via the drilling and compression method. The microstructure of crack healing zone was observed using optical microscopy and scanning electron microscopy. The mechanical properties of crack healing zone at room temperature were tested. The results show that there are two mechanisms of crack healing in the low carbon steel. Crack healing is caused by atomic diffusion at lower temperatures, and mainly depends on recrystallization and grain growth at higher temperatures. The microstructural evolution of crack healing zone can be divided into four stages, and the fracture morphology of crack healing zone can be classified into five stages. At the initial healing stage, the fracture exhibits brittle or low ductile dimple fracture. The ultimate fracture mode is dimple and quasi-cleavage mixed fracture. Fine grain microstructures improve the ultimate tensile strength of crack healing zone, which is even higher than that of the matrix. The strength recovery rate is higher than that of the plasticity.

  18. Causes of the fissure formation with shrinkage of metal on low carbon steel slabs

    International Nuclear Information System (INIS)

    Ksenzuk, F.A.; Khudas, A.L.; Zelenskaya, D.P.

    1977-01-01

    The causes have been investigated underlying the formation of fissures with spread of metal on low-carbon steel slabs during hot rolling. Metallographic investigations of templates from various sections of work pieces from 15-ton ingots of 08 ps (kp) steels have indicated that the fissures on the slabs are formed after the metal spreads along the small plane and the work piece thins out in the course of rolling because of the opening of large thin-walled honeycomb bubbles. The phenomenon was confirmed schematically on a model in the form of a slab-shaped lead specimen with longitudinal hole of a variable diameter close to one of the edges

  19. The effect of hydrogen on the parameters of plastic deformation localization in low carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Lunev, Aleksey G., E-mail: agl@ispms.tsc.ru, E-mail: nadjozhkin@ispms.tsc.ru; Nadezhkin, Mikhail V., E-mail: agl@ispms.tsc.ru, E-mail: nadjozhkin@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Shlyakhova, Galina V., E-mail: shgv@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and Seversk State Technological Institute (National Research Nuclear University MEPhI), Seversk, 636036 (Russian Federation); Barannikova, Svetlana A., E-mail: bsa@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation); Zuev, Lev B., E-mail: lbz@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2014-11-14

    In the present study, the effect of interstitial hydrogen atoms on the mechanical properties and plastic strain localization patterns in tensile tested polycrystals of low-carbon steel Fe-0.07%C has been studied using double exposure speckle photography technique. The main parameters of plastic flow localization at various stages of deformation hardening have been determined in polycrystals of steel electrolytically saturated with hydrogen in a three-electrode electrochemical cell at a controlled constant cathode potential. Also, the effect of hydrogen on changing of microstructure by using optical microscopy has been demonstrated.

  20. Modeling of roughness effect on hydrogen permeation in a low carbon steel

    OpenAIRE

    Carreño, J. A.; Uribe, I.; Carrillo, J. C.

    2003-01-01

    A model is presented to evaluate the effect of the roughness and the profile of concentration of hydrogen in a low carbon steel. The model takes advantage of the Fick's Second Law, to predict the transport of hydrogen in the steel. The problem is treated as a variational one and its space solution is made numerically by means of the Finite Elements Method, while the temporal equation is solved via the Finite Differences Method, in order to determine the concentration profiles of Hydrogen in t...

  1. Bainitic Transformation and Properties of Low Carbon Carbide-Free Bainitic Steels with Cr Addition

    Directory of Open Access Journals (Sweden)

    Mingxing Zhou

    2017-07-01

    Full Text Available Two low carbon carbide-free bainitic steels (with and without Cr addition were designed, and each steel was treated by two kinds of heat treatment procedure (austempering and continuous cooling. The effects of Cr addition on bainitic transformation, microstructure, and properties of low carbon bainitic steels were investigated by dilatometry, metallography, X-ray diffraction, and a tensile test. The results show that Cr addition hinders the isothermal bainitic transformation, and this effect is more significant at higher transformation temperatures. In addition, Cr addition increases the tensile strength and elongation simultaneously for austempering treatment at a lower temperature. However, when the austempering temperature is higher, the strength increases and the elongation obviously decreases by Cr addition, resulting in the decrease in the product of tensile strength and elongation. Meanwhile, the austempering temperature should be lower in Cr-added steel than that in Cr-free steel in order to obtain better comprehensive properties. Moreover, for the continuous cooling treatment in the present study, the product of tensile strength and elongation significantly decreases with Cr addition due to more amounts of martensite.

  2. Development of high strength hot rolled low carbon copper-bearing steel containing nanometer sized carbides

    Energy Technology Data Exchange (ETDEWEB)

    Phaniraj, M.P. [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Shin, Young-Min [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Joonho [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Goo, Nam Hoon [Sheet Product Design Group, Hyundai Steel Co., North Industrial Street 1400, 343-823, DangJin 343-823 (Korea, Republic of); Kim, Dong-Ik; Suh, Jin-Yoo; Jung, Woo-Sang [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Shim, Jae-Hyeok, E-mail: jhshim@kist.re.kr [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Choi, In-Suk, E-mail: insukchoi@kist.re.kr [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2015-05-01

    A low carbon ferritic steel was alloyed with Ti, Mo and Cu with the intention of achieving greater increment in strength by multiple precipitate strengthening. The steel is hot rolled and subjected to interrupted cooling to enable precipitation of Ti–Mo carbides and copper. Thermodynamic calculations were carried out to determine equilibrium phase fractions at different temperatures. Microstructure characterization using transmission electron microscopy and composition analysis revealed that the steel contains ~5 nm size precipitates of (Ti,Mo)C. Precipitation kinetics calculations using MatCalc software showed that mainly body centered cubic copper precipitates of size < 5nm form under the cooling conditions in the present study. The steel has the high tensile strength of 853 MPa and good ductility. The yield strength increases by 420 MPa, which is more than that achieved in hot rolled low carbon ferritic steels with only copper precipitates or only carbide precipitates. The precipitation and strengthening contribution of copper and (Ti,Mo)C precipitates and their effect on the work hardening behavior is discussed.

  3. Strain-tempering of low carbon martensite steel wire by rapid heating

    International Nuclear Information System (INIS)

    Torisaka, Yasunori; Kihara, Junji

    1978-01-01

    In the production of prestressed concrete steel wires, a series of the cold drawing-patenting process are performed to improve the strength. In order to reduce cyclic process, the low carbon martensite steel wire which can be produced only by the process of hot rolling and direct quench has been investigated as strain-tempering material. When strain-tempering is performed on the low carbon martensite steel wire, stress relaxation (Re%) increases and mechanical properties such as total elongation, reduction of area, ultimate tensile strength and proof stress decrease remarkably by annealing. In order to shorten the heating time, the authors performed on the steel wire the strain-tempering with a heating time of 1.0 s using direct electrical resistance heating and examined the effects of rapid heating on the stress relaxation and the mechanical properties. Stress relaxation decreases without impairment of the mechanical properties up to a strain-tempering temperature of 573 K. Re(%) after 10.8 ks is 0% at the testing temperature 301 K, 0.49% at 363 K and 1.39% at 433 K. (auth.)

  4. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    International Nuclear Information System (INIS)

    Mejia, I.; Bedolla-Jacuinde, A.; Maldonado, C.; Cabrera, J.M.

    2011-01-01

    Research highlights: → Effect of boron on the hot ductility behavior of a low carbon NiCrVCu AHSS. → Boron addition of 117 ppm improves hot ductility over 100% in terms of RA. → Hot ductility improvement is associated with segregation/precipitation of boron. → Typical hot ductility recovery at lower temperatures does not appear in this steel. → Hot ductility loss is associated with precipitates/inclusions coupled with voids. - Abstract: The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s -1 . Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless, both steels showed poor ductility when tested at the lowest temperatures (650, 750 and 800 deg. C), and such behavior is associated to the precipitation of vanadium carbides/nitrides and inclusions, particularly MnS and CuS particles. The fracture mode of the low carbon advanced high strength steel microalloyed with boron seems to be more ductile than the steel without boron addition. Furthermore, the fracture surfaces of specimens tested at temperatures showing the highest ductility (900 and 1000 deg. C) indicate that the fracture mode is a result of ductile failure, while in the region of poor ductility the fracture mode is of the ductile-brittle type failure. It was shown that precipitates and/or inclusions coupled with voids play a meaningful role on the crack nucleation mechanism which in turn causes a hot ductility loss. Likewise, dynamic recrystallization (DRX) which always results in restoration of ductility only occurs in the range from 900 to 1000 deg. C. Results are discussed in terms of boron segregation towards

  5. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, I., E-mail: imejia@umich.mx [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio ' U' , Ciudad Universitaria, 58066 Morelia, Michoacan (Mexico); Bedolla-Jacuinde, A.; Maldonado, C. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio ' U' , Ciudad Universitaria, 58066 Morelia, Michoacan (Mexico); Cabrera, J.M. [Departament de Ciencia dels Materials i Enginyeria Metal.lurgica, ETSEIB - Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundacio CTM Centre Tecnologic, Av. de las Bases de Manresa 1, 08240 Manresa (Spain)

    2011-05-25

    Research highlights: {yields} Effect of boron on the hot ductility behavior of a low carbon NiCrVCu AHSS. {yields} Boron addition of 117 ppm improves hot ductility over 100% in terms of RA. {yields} Hot ductility improvement is associated with segregation/precipitation of boron. {yields} Typical hot ductility recovery at lower temperatures does not appear in this steel. {yields} Hot ductility loss is associated with precipitates/inclusions coupled with voids. - Abstract: The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s{sup -1}. Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless, both steels showed poor ductility when tested at the lowest temperatures (650, 750 and 800 deg. C), and such behavior is associated to the precipitation of vanadium carbides/nitrides and inclusions, particularly MnS and CuS particles. The fracture mode of the low carbon advanced high strength steel microalloyed with boron seems to be more ductile than the steel without boron addition. Furthermore, the fracture surfaces of specimens tested at temperatures showing the highest ductility (900 and 1000 deg. C) indicate that the fracture mode is a result of ductile failure, while in the region of poor ductility the fracture mode is of the ductile-brittle type failure. It was shown that precipitates and/or inclusions coupled with voids play a meaningful role on the crack nucleation mechanism which in turn causes a hot ductility loss. Likewise, dynamic recrystallization (DRX) which always results in restoration of ductility only occurs in the range from 900 to 1000 deg. C. Results are discussed in terms of

  6. Influence of refining time on nonmetallic inclusions in a low-carbon, silicon-killed steel

    International Nuclear Information System (INIS)

    Fernandes, Marcolino; Pires, Jose Carlos; Cheung, Noe; Garcia, Amauri

    2003-01-01

    Nonmetallic inclusions are harmful to the mechanical properties of every kind of steel produced worldwide. The greater the size of the inclusion present in the structure of a determined kind of steel, the greater its negative effect on the quality of the steel. Therefore, the objective of this work was to investigate the size, the quantity, the shape and the chemical composition of nonmetallic inclusions formed throughout the refining process of silicon-killed, low-carbon steel, as a function of the treatment time in a ladle furnace, trying to ensure the flotation of inclusions bigger than 25 μm. This investigation was carried out using a scanning electron microscope (SEM), with an analysis system using energy dispersive spectometry (EDS). Based on this work, it was possible to know more precisely the nature of the inclusions, the necessary time to ensure flotation of large inclusions, the efficiency of the slag to capture the inclusions, and the inclusion level of the steel throughout its refining process to try to obtain a higher quality steel product

  7. Variations of microstructure and properties of 690 MPa grade low carbon bainitic steel after tempering

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Rui [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan Shandong 250061 (China); Li, Shengli, E-mail: lishengli@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan Shandong 250061 (China); Li, Zhenshun; Tian, Lei [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan Shandong 250061 (China)

    2012-12-15

    The variations of microstructure, mechanical properties and electrical resistivity of 690 MPa grade low carbon bainitic steel tempered at different temperatures were investigated with Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and double-arm Bridge. The results show that the appearance of granular bainite, decomposition of retained austenite, variations of dislocation density and solid solution of microalloying elements are the main reasons for variations of mechanical properties and electrical resistivity. Electrical resistivity reflects the solution content of microalloying elements and variations of dislocation density, which can be used as a fast and effective way to analyze the microstructure of materials.

  8. Transformation Stasis Phenomenon of Bainite Formation in Low-Carbon, Multicomponent Alloyed Steel

    Science.gov (United States)

    Lan, Liangyun; Kong, Xiangwei

    2017-11-01

    The transformation stasis phenomenon of bainite formation in low-carbon steel was detected using a high-resolution dilatometer. The phenomenon occurred at different stages for different isothermal temperatures. In combination with microstructural observation, the calculated overall activation energy of transformation and interface migration velocity shed new light on the cause of formation of the stasis phenomenon. The temporary stasis formed at the initial stage of phase transformation for high isothermal temperature was attributed to the drag effect of substitutional atoms, which leads to low-interface migration velocity and large overall activation energy.

  9. Stress and Strain Gradients in a Low Carbon Steel Deformed under Heavy Sliding

    DEFF Research Database (Denmark)

    Zhang, Xiaodan; Hansen, Niels; Huang, Xiaoxu

    A recent study [1] has shown that a microstructure can be refined to a record low of 5 nm and that dislocation glide is still a controlling mechanism at this length scale. In this study, by heavy rotatory sliding of a low carbon steel a gradient structure has been produced extending to about 2.5 mm...... on the deformation microstructure using the classic stress-structure relationship. Computational and materials modelling has been advanced from bulk to gradient structures leading to dissemination of constitutive stress-strain equations in gradient structures....

  10. Analysis of recrystallization and grain growth in ultra low carbon steels using EBSD

    International Nuclear Information System (INIS)

    Novillo, E.; Petite, M. M.; Bocos, J. L.; Gutierrez, I.

    2004-01-01

    This work is focused on the study of recrystallization texture and micro texture in a cold rolled ultra low carbon steel and its relationship with the global texture. Aspects like nucleation, evolution of the volume fraction and grain size were considered. An important grain selection associated with a significant size and number advantages of the recrystallized grains is observed. This grain selection gives rise to the development, at the latest stages of recrystallization, of a strong γ-fibre associated to good drawing properties. (Author) 24 refs

  11. Substructural evolution during cyclic torsion of drawn low carbon steel bars

    International Nuclear Information System (INIS)

    Correa, E.C.S.; Aguilar, M.T.P.; Monteiro, W.A.; Cetlin, P.R.

    2006-01-01

    Strain softening effects have been previously observed in drawn low carbon steel bars as a result of cyclic torsion experiments. In this paper, the substructural aspects related to the phenomenon have been investigated. Single pass drawn bars were subjected to a quarter, to a half, to a full torsion cycle and to 10 such cycles. Transmission electron microscopy revealed the development of extended microbands crossing the former dislocation arrangement of the drawn metal, which evolves to a rectangular shaped subgrains structure as torsion deformation is conducted

  12. Effect of quenching techniques on the mechanical properties of low carbon structural steel

    Directory of Open Access Journals (Sweden)

    K. Miernik

    2010-07-01

    Full Text Available The paper presents the results of the impact of incomplete quenching technique on the mechanical properties of low carbon structural steel.Significant influence of the heating method to the α + γ field was observed on the strength and plasticity after hardening process. The best combination of mechanical properties was obtained for the 3th technique consisting of pre-heating the material to the austenite field, next cooling to the appropriate temperature in the α + γ and hardening from that dual phase region. The high level of toughness with relatively high strength were observed, compared to the properties obtained for the two other ways to quench annealing (incomplete hardening.

  13. Coupled gamma/alpha phase transformations in low-carbon steels

    Science.gov (United States)

    Mizutani, Yasushi

    Since steels have been the most prevalently utilized materials for many years, the desire for steels with low alloying components with a well-balanced combination of high strength and toughness is increasing. Low carbon steels consisting of bainitic microstructures are ideally suited to meeting such technological and economic requirements. Thus it is extremely important to fully clarify the mechanism of bainite formation in order to produce this type of engineering steel by optimized alloy and process design. This research focuses on understanding the mechanism of coupled displacive/diffusional gamma/alpha transformation in low-carbon steels including bainitic and martensitic transformation, and establishing a more comprehensive and physically rational computational model for predictive control of coupled gamma/alpha transformation phenomena. Models for coupled gamma/alpha phase transformation proposed in this study are based on a mechanistic and unified theory and the following assumptions: (1) The energy dissipation due to interface motion can be linearly combined with the energy dissipation due to carbon diffusion. (2) The carbon concentrations at the interface in both gamma and alpha phases are constrained by an interface solute trapping law. (3) Interface motion during nucleation is also governed by the carbon diffusion field velocity. (4) The response function of glissile interface motion can be expressed in the form of thermally activated dislocation glide. In contrast to the conventional semi-empirical models of the previous literature, the computational model proposed in this study is demonstrated to successfully provide a comprehensive and quantitative prediction of the effects of temperature, composition, microstructure, and the interactions among them. This includes the effects of substitutional solutes, morphology of the parent gamma phase, density of nucleation sites, temperature dependent variation of flow stress of matrix, and dynamic recovery of

  14. Quenching and partitioning treatment of a low-carbon martensitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiyama, Toshihiro, E-mail: toshi@zaiko.kyushu-u.ac.jp [Department of Materials Science and Engineering, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Tobata, Junya; Tao, Teruyuki [Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Nakada, Nobuo; Takaki, Setsuo [Department of Materials Science and Engineering, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer The amount of retained austenite was increased by Q and P treatment in 12Cr-0.1C steel. Black-Right-Pointing-Pointer Ideal carbon concentrations in austenite and ferrite were calculated assuming CCE condition. Black-Right-Pointing-Pointer The optimum partitioning treatment condition for 12Cr-0.1C steel was found. Black-Right-Pointing-Pointer The strength-ductility balance of 12Cr-0.1C steel was improved by TRIP effect. - Abstract: Quenching and partitioning (Q and P) treatment was applied to a commercial low-carbon martensitic stainless steel, AISI Type 410 (Fe-12Cr-0.1C). The quench interruption temperature was optimized with consideration of the ideal carbon concentration in untransformed austenite after partitioning to lower the Ms temperature to room temperature. After partitioning at an appropriate temperature, a significant fraction of austenite was retained through the enrichment of carbon into the untransformed austenite. It was also suggested that the addition of silicon is not necessarily required for the Q and P treatment of 12Cr steel because of the retardation of carbide precipitation at the partitioning temperature owing to the large amount of chromium. Tensile testing revealed that the Q and P-treated material exhibited a significantly improved strength-ductility balance compared with conventional quench-and-tempered materials due to the transformation-induced plasticity (TRIP) effect by the retained austenite.

  15. Quenching and partitioning treatment of a low-carbon martensitic stainless steel

    International Nuclear Information System (INIS)

    Tsuchiyama, Toshihiro; Tobata, Junya; Tao, Teruyuki; Nakada, Nobuo; Takaki, Setsuo

    2012-01-01

    Highlights: ► The amount of retained austenite was increased by Q and P treatment in 12Cr–0.1C steel. ► Ideal carbon concentrations in austenite and ferrite were calculated assuming CCE condition. ► The optimum partitioning treatment condition for 12Cr–0.1C steel was found. ► The strength–ductility balance of 12Cr–0.1C steel was improved by TRIP effect. - Abstract: Quenching and partitioning (Q and P) treatment was applied to a commercial low-carbon martensitic stainless steel, AISI Type 410 (Fe–12Cr–0.1C). The quench interruption temperature was optimized with consideration of the ideal carbon concentration in untransformed austenite after partitioning to lower the Ms temperature to room temperature. After partitioning at an appropriate temperature, a significant fraction of austenite was retained through the enrichment of carbon into the untransformed austenite. It was also suggested that the addition of silicon is not necessarily required for the Q and P treatment of 12Cr steel because of the retardation of carbide precipitation at the partitioning temperature owing to the large amount of chromium. Tensile testing revealed that the Q and P-treated material exhibited a significantly improved strength–ductility balance compared with conventional quench-and-tempered materials due to the transformation-induced plasticity (TRIP) effect by the retained austenite.

  16. Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, W.R.; Peixoto, L.C.; Garcia, L.R.; Garcia, A. [Department of Materials Engineering, State University of Campinas, SP (Brazil)

    2009-10-15

    Dual-phase (DP) steels are produced from a specific heat treatment procedure and have recently emerged as a potential class of engineering materials for a number of structural and automobile applications. Such steels have high strength-to-weight ratio and reasonable formability. The present study aims to investigate the effects of four different and conventional heat treatments (i.e., hot rolling, normalizing, annealing, and intercritical annealing) on the resulting microstructural patterns and on the electrochemical corrosion behavior. Electrochemical impedance spectroscopy (EIS) and Tafel plots were carried out on heat treated steel samples in a 0.5 M NaCl solution at 25 C with neutral pH. An equivalent circuit analysis was also used to provide quantitative support for the discussions. The normalizing and the annealing heat treatments have provided the highest and the lowest corrosion resistances, respectively. The intercritical annealing and as-received (hot rolled) low carbon steel samples have shown similar corrosion behavior. Although a deleterious effect on the corrosion resistance has been verified for DP steel due to the residual stress from the martensite formation, it combines good mechanical properties with intermediate electrochemical corrosion resistance. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  17. The kinetics of dynamic recrystallization of a low carbon vanadium-nitride microalloyed steel

    International Nuclear Information System (INIS)

    Zhao, Baochun; Zhao, Tan; Li, Guiyan; Lu, Qiang

    2014-01-01

    Single-pass compression tests were performed on a Gleeble-3800 thermo-mechanical simulator to study the dynamic recrystallization behavior of a low carbon vanadium-nitride microalloyed steel at the temperature in the range from 900 °C to 1050 °C and strain rate in the range from 0.1 s −1 to 10 s −1 . Based on the flow curves from the tests, the effects of temperature and strain rate on the dynamic recrystallization behavior were analyzed. With the assistance of the process parameters, constitutive equations were used to obtain the activation energy and hot working equation. The strain hardening rate versus stress curves were used to determine the critical stress (strain) or the peak stress (strain). The dependence of the characteristic values on Zener–Hollomon was found. The dynamic recrystallization kinetics model of the tested steel was constructed and the validity was confirmed based on the experimental results

  18. Tailoring the gradient ultrafine-grained structure in low-carbon steel during drawing with shear

    Directory of Open Access Journals (Sweden)

    G. I. Raab

    2016-04-01

    Full Text Available Conventional drawing and drawing with shear were conducted on the rods of low-carbon steel. Deformation by simple drawing forms basically a homogenous structure and leads to a uniform change in microhardness along the billet volume. A comparative analysis of the models of these processes showed that shear drawing of steel at room temperature reduces energy characteristics in half, normal forces on the die – by 1,8, and enhances the strain intensity from 0,5 to 1,6. During drawing with shear, strain-induced cementite dissolution occurs and a gradient structure is formed, which increases the microhardness of the surface layer up to values close to 7 000 MPa.

  19. Bake hardening of ultra-fine grained low carbon steel produced by constrained groove pressing

    International Nuclear Information System (INIS)

    Alihosseini, H.; Dehghani, K.

    2012-01-01

    Highlights: ► BH of UFG low carbon steel sheets was studied. ► Three passes of CGP are used for producing of UFG sheets. ► Maximum BH was achieved to the UFG specimen pre-strained 8% by baking at 250 °C. - Abstract: In the present work, the bake hardening of ultra-fine grained low carbon steel was compared with that of its coarse-grain counterpart. The ultra-fine grained sheets were produced by applying three passes of constrained groove pressing resulting the grains of 260–270 nm. The microstructure of ultra-fine grain specimens were characterized using electron back-scatter diffraction technique. Then, the bake hardenability of ultra-fine grain and coarse-grain samples were compared by pre-straining to 4, 6 and 8% followed by baking at 150 °C and 250 °C for 20 min. The results show that in case of baking at 250 °C, there was an increase about 108%, 93%, and 72% in the bake hardening for 4%, 6% and 8% pre-strain, respectively. As for baking at 150 °C, these values were 170%, 168%, and 100%, respectively for 4%, 6% and 8% pre-strain. The maximum in bake hardenability (103 MPa) and final yield stress (563 MPa) were pertaining to the ultra-fine grain specimen pre-strained 8% followed by baking at 250 °C.

  20. Corrosion Inhibition of Cold-rolled Low Carbon Steel with Pulse Fiber Laser Ablation in Water

    Science.gov (United States)

    Chan, Sze Ney; Wong, Wai Yin; Walvekar, Rashmi; Kadhum, Abdul Amir H.; Khalid, Mohammad; Lim, Kean Long

    2018-04-01

    This study aims at the use of a fiber laser for modifying the surface properties of cold-rolled low carbon steel via a pulse laser ablation technique in water. The effect on the corrosion behavior of the fiber laser-treated metal surface was investigated in NaCl and HCl environments. Electrochemical tests showed significant improvement in the corrosion resistance of the laser-treated sample in NaCl, with an increase in open-circuit potential (OCP) from - 0.65 to - 0.60 V and an inhibition efficiency of 89.22% as obtained from the impedance study. Such improvement was less significant in an acidic environment. Lower corrosion rates of 20.9 mpy and 5.819 × 103 mpy were obtained for the laser-treated samples in neutral and acidic electrolytes, respectively, than the corrosion rates obtained for the as-received samples (33.2 mpy and 11.98 × 103 mpy). Morphological analysis indicated a passive film built by spherical grains of regular size on the metal surface after laser treatment. The corrosion inhibition effects in NaCl were evident by the nonexistence of the common corrosion products of lepidocrocite and crystalline structures that were seen on as-received samples; only polyhedral crystals with micrograins grown on them were seen covering the laser-treated surface. Therefore, the laser treatment using a fiber laser source improved the corrosion resistance of cold-rolled low carbon steel.

  1. Failure prediction of low-carbon steel pressure vessel and cylindrical models

    International Nuclear Information System (INIS)

    Zhang, K.D.; Wang, W.

    1987-01-01

    The failure loads predicted by failure assessment methods (namely the net-section stress criterion; the EPRI engineering approach for elastic-plastic analysis; the CEGB failure assessment route; the modified R6 curve by Milne for strain hardening; and the failure assessment curve based on J estimation by Ainsworth) have been compared with burst test results on externally, axially sharp notched pressure vessel and open-ended cylinder models made from typical low-carbon steel St45 seamless tube which has a transverse true stress-strain curve of straight-line and parabola type and a high value of ultimate strength to yield. It was concluded from the comparison that whilst the net-section stress criterion and the CEGB route did not give conservative predictions, Milne's modified curve did give a conservative and good prediction; Ainsworth's curve gave a fairly conservative prediction; and EPRI solutions also could conditionally give a good prediction but the conditions are still somewhat uncertain. It is suggested that Milne's modified R6 curve is used in failure assessment of low-carbon steel pressure vessels. (author)

  2. Studying on tempering transformation and internal friction for low carbon bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weijuan, E-mail: liweijuan826@163.com; Cai, Mingyu; Wang, Dong; Zhang, Junwei; Zhao, Shengshi; Shao, Peiying

    2017-01-02

    The changes of microstructure during the process of tempering transformation were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction and internal friction (IF) for low carbon bainite steel. The yield strength of the steel was tested after tempering transformation. The results showed that the microstructures of the experimental steel in rolled state were composed of lath bainite and granular bainite with a little Mo{sub 2}C and NbC precipitates. The lath width of bainite increased continuously with the tempering time. More cell structures with different orientations were formed in bainite laths. Furthermore, poly-gonization gradually began in some laths. The microstructure of granular bainite increased and was coarsened when it devoured the lath bainite continuously. The dislocation density of the bainitic ferrite decreased continuously as Mo{sub 2}C and NbC precipitations were further increasing. The peak value of Snoek decreased continuously in internal friction-temperature spectrum. The peak value of SKK at the surface decreased at first and then increased. The peak value of SKK at the center decreased firstly and then had little change. Besides, the yield strength of the steel increased firstly and then decreased.

  3. Studying on tempering transformation and internal friction for low carbon bainitic steel

    International Nuclear Information System (INIS)

    Li, Weijuan; Cai, Mingyu; Wang, Dong; Zhang, Junwei; Zhao, Shengshi; Shao, Peiying

    2017-01-01

    The changes of microstructure during the process of tempering transformation were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction and internal friction (IF) for low carbon bainite steel. The yield strength of the steel was tested after tempering transformation. The results showed that the microstructures of the experimental steel in rolled state were composed of lath bainite and granular bainite with a little Mo 2 C and NbC precipitates. The lath width of bainite increased continuously with the tempering time. More cell structures with different orientations were formed in bainite laths. Furthermore, poly-gonization gradually began in some laths. The microstructure of granular bainite increased and was coarsened when it devoured the lath bainite continuously. The dislocation density of the bainitic ferrite decreased continuously as Mo 2 C and NbC precipitations were further increasing. The peak value of Snoek decreased continuously in internal friction-temperature spectrum. The peak value of SKK at the surface decreased at first and then increased. The peak value of SKK at the center decreased firstly and then had little change. Besides, the yield strength of the steel increased firstly and then decreased.

  4. SPEED DEPENDENCE OF ACOUSTIC VIBRATION PROPAGATION FROM THE FERRITIC GRAIN SIZE IN LOW-CARBON STEEL

    Directory of Open Access Journals (Sweden)

    I. A. Vakulenko

    2015-08-01

    Full Text Available Purpose. It is determining the nature of the ferrite grain size influence of low-carbon alloy steel on the speed propagation of acoustic vibrations. Methodology. The material for the research served a steel sheet of thickness 1.4 mm. Steel type H18T1 had a content of chemical elements within grade composition: 0, 12 % C, 17, 5 % Cr, 1 % Mn, 1, 1 % Ni, 0, 85 % Si, 0, 9 % Ti. The specified steel belongs to the semiferritic class of the accepted classification. The structural state of the metal for the study was obtained by cold plastic deformation by rolling at a reduction in the size range of 20-30 % and subsequent recrystallization annealing at 740 – 750 ° C. Different degrees of cold plastic deformation was obtained by pre-selection of the initial strip thickness so that after a desired amount of rolling reduction receives the same final thickness. The microstructure was observed under a light microscope, the ferrite grain size was determined using a quantitative metallographic technique. The using of X-ray structural analysis techniques allowed determining the level of second-order distortion of the crystal latitude of the ferrite. The speed propagation of acoustic vibrations was measured using a special device such as an ISP-12 with a working frequency of pulses 1.024 kHz. As the characteristic of strength used the hardness was evaluated by the Brinell’s method. Findings. With increasing of ferrite grain size the hardness of the steel is reduced. In the case of constant structural state of metal, reducing the size of the ferrite grains is accompanied by a natural increasing of the phase distortion. The dependence of the speed propagation of acoustic vibrations up and down the rolling direction of the ferrite grain size remained unchanged and reports directly proportional correlation. Originality. On the basis of studies to determine the direct impact of the proportional nature of the ferrite grain size on the rate of propagation of sound

  5. Xanthium strumarium leaves extracts as a friendly corrosion inhibitor of low carbon steel in hydrochloric acid: Kinetics and mathematical studies

    Directory of Open Access Journals (Sweden)

    Anees A. Khadom

    2018-06-01

    Full Text Available Corrosion inhibition of low carbon steel in 1 M HCl was investigated in absence and presence of Xanthium strumarium leaves (XSL extracts as a friendly corrosion inhibitor. The effect of temperature and inhibitor concentration was studied using weight loss method. The result obtained shown that Xanthium strumarium leaves extracts act as an inhibitor for low carbon steel in HCl and reduces the corrosion rate. The inhibition efficiency was found to increases with increase in inhibitor concentration and temperature. Higher inhibition efficiency was 94.82% at higher level of inhibitor concentration and temperature. The adsorption of Xanthium strumarium leaves extracts was found to obey Langmuir adsorption isotherm model. The values of the free energy of adsorption was more than −20 kJ/mol, which is indicative of mixed mode of physical and chemical adsorption. Keywords: Corrosion, Green inhibitor, Natural extracts, Low carbon steel, Acid, Adsorption

  6. Nano-sized precipitation and properties of a low carbon niobium micro-alloyed bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.J. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada); Ma, X.P. [Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada); Shang, C.J., E-mail: cjshang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wang, X.M. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Subramanian, S.V. [Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada)

    2015-08-12

    The present work focuses on microstructure evolution and precipitation strengthening during tempering at region of 550–680 °C to elucidate the structure–property relationship in the steel. The effect of tempering on the development of a 700 MPa grade high strength hot rolled cost-effective bainitic steel was studied for infrastructure applications. Granular bainite with dispersed martenisit–austenite (M–A) constituents in the bainitic ferrite matrix was obtained after hot rolling and air cooling to room temperature. The decomposition of M–A constituents to cementite carbides and the precipitation of nano-sized NbC carbides in bainitic matrix on tempering were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Nano-sized precipitates of NbC precipitated during tempering were in average diameter of ~4.1–6.1 nm. There were ~86–173 MPa increases in yield strength after tempering at region of 550–680 °C. It is noticeable that those nano-sized NbC precipitates provide an effective way to significantly increase the strength of the low carbon bainitic steel. High yield strength of 716 MPa with high ductility (uniform elongation of 9.3% and total elongation of 22.4%), low yield to tensile ratio of 0.9 and good low temperature toughness of 47 J (half thickness) at –40 °C was obtained after tempering at 680 °C for 30 min.

  7. Spectroscopic investigation of plasma electrolytic borocarburizing on q235 low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Run [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Zhenjiang Watercraft College, Zhenjiang 212000, Jiangsu (China); Wang, Bin; Wu, Jie [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Xue, Wenbin, E-mail: xuewb@bnu.edu.cn [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Jin, Xiaoyue; Du, Jiancheng; Hua, Ming [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2014-12-01

    Highlights: • The plasma discharge behaviors for PEB/C on steels were evaluated by OES. • Electron temperature, concentration, atomic ionization degree were calculated. • The decomposition mechanism of electrolyte and was analyzed. - Abstract: A plasma electrolytic borocarburizing process (PEB/C) in borax electrolyte with glycerin additive was employed to fabricate a hardening layer on Q235 low-carbon steel. Optical emission spectroscopy (OES) was utilized to investigate the spectroscopy characteristics of plasma discharge around the steel during PEB/C process. Some plasma parameters were calculated in terms of OES. The electron temperature and electron concentration in plasma discharge zone is about 3000–12,000 K and 2 × 10{sup 22} m{sup −3}–1.4 × 10{sup 23} m{sup −3}. The atomic ionization degrees of iron, carbon and boron are 10{sup −16}–10{sup −3}, and 10{sup −23}–10{sup −6}, 10{sup −19}–10{sup −4}, respectively, which depend on discharge time. The surface morphology and cross-sectional microstructure of PEB/C hardening layer were observed, and the electrolyte decomposition and plasma discharge behaviors were discussed.

  8. Whole through processing understanding of rolling and recrystallization textures in low carbon steels

    International Nuclear Information System (INIS)

    Roatta, A; Fourty, A; Bolmaro, R.E

    2008-01-01

    Processing steels to achieve particular useful properties is a science as well as an art. Many of the properties of modern steels are a successful combination of empiric and scientific knowledge. Deep drawing low carbon steels have been used and improved through many decades of research and technological advance. However the micro mechanisms involved in the development of particular microstructures and properties are still under discussion. The current paper shows an integrated attempt to obtain consistent microscopical data from micromechanical simulations coupled with recrystallization and phase transformation codes. The simulations are performed in a way such that the information obtained from certain temperature, level or process is used in the next step to proceed further. The goal is not avoiding experiments but having a whole through scale and time integration for judging the validity of similar parameters and assumptions during the different processing steps. The simulations include high and low temperature deformation and recrystallization in the austenite region, phase transformation to room temperature, low temperature deformation and recrystallization in the ferrite phase region. The results are compared with experiments available in the literature

  9. Electrochemical Corrosion Behavior of Low Carbon I-Beam Steels In Simulated Yucca Mountain Repository Environment

    Energy Technology Data Exchange (ETDEWEB)

    Arjunan, Venugopal; Lamb, Joshua; Chandra, Dhanesh; Daemen, Jack; Jones, Denny A.; Engelhard, Mark H.; Lea, Alan S.

    2005-04-01

    The electrochemical corrosion behavior of low carbon steel was examined in a simulated Yucca Mountain (YM) ground water by varying the electrolyte concentration and temperature under aerated and deaerated conditions. The results show that in deaerated conditions, the corrosion rate is low in the order of 0.6 to 4.5mpy, between 25 to 85 C, respectively. However, in aerated conditions the measured rates were expectedly very high, in the order of 3-55mpy in the above mentioned temperature levels. The rates initially increased up to 45 C, and a decreasing trend was observed with further increase in temperature from 65 to 85 C. The maximum corrosion rate was occurred at 45 C (54.5mpy). The low corrosion rates observed in all deaerated conditions, and in aerated solutions at higher temperatures were due to the preferential adsorption of Mg-species on the steel surface, as identified by XPS analyses. The results also indicate possible localized corrosion behavior of carbon steel in aerated conditions up to 45 C.

  10. Electrochemical Corrosion Behavior of Low Carbon I-Beam Steels In Simulated Yucca Mountain Repository Environment

    International Nuclear Information System (INIS)

    Arjunan, Venugopal; Lamb, Joshua; Chandra, Dhanesh; Daemen, Jack; Jones, Denny A.; Engelhard, Mark H.; Lea, Alan S.

    2005-01-01

    The electrochemical corrosion behavior of low carbon steel was examined in a simulated Yucca Mountain (YM) ground water by varying the electrolyte concentration and temperature under aerated and deaerated conditions. The results show that in deaerated conditions, the corrosion rate is low in the order of 0.6 to 4.5mpy, between 25 to 85 C, respectively. However, in aerated conditions the measured rates were expectedly very high, in the order of 3-55mpy in the above mentioned temperature levels. The rates initially increased up to 45 C, and a decreasing trend was observed with further increase in temperature from 65 to 85 C. The maximum corrosion rate was occurred at 45 C (54.5mpy). The low corrosion rates observed in all deaerated conditions, and in aerated solutions at higher temperatures were due to the preferential adsorption of Mg-species on the steel surface, as identified by XPS analyses. The results also indicate possible localized corrosion behavior of carbon steel in aerated conditions up to 45 C

  11. Spectroscopic investigation of plasma electrolytic borocarburizing on q235 low-carbon steel

    International Nuclear Information System (INIS)

    Liu, Run; Wang, Bin; Wu, Jie; Xue, Wenbin; Jin, Xiaoyue; Du, Jiancheng; Hua, Ming

    2014-01-01

    Highlights: • The plasma discharge behaviors for PEB/C on steels were evaluated by OES. • Electron temperature, concentration, atomic ionization degree were calculated. • The decomposition mechanism of electrolyte and was analyzed. - Abstract: A plasma electrolytic borocarburizing process (PEB/C) in borax electrolyte with glycerin additive was employed to fabricate a hardening layer on Q235 low-carbon steel. Optical emission spectroscopy (OES) was utilized to investigate the spectroscopy characteristics of plasma discharge around the steel during PEB/C process. Some plasma parameters were calculated in terms of OES. The electron temperature and electron concentration in plasma discharge zone is about 3000–12,000 K and 2 × 10 22 m −3 –1.4 × 10 23 m −3 . The atomic ionization degrees of iron, carbon and boron are 10 −16 –10 −3 , and 10 −23 –10 −6 , 10 −19 –10 −4 , respectively, which depend on discharge time. The surface morphology and cross-sectional microstructure of PEB/C hardening layer were observed, and the electrolyte decomposition and plasma discharge behaviors were discussed

  12. Nondestructive characterization of recovery and recrystallization in cold rolled low carbon steel by magnetic hysteresis loops

    International Nuclear Information System (INIS)

    Martinez-de-Guerenu, A.; Gurruchaga, K.; Arizti, F.

    2007-01-01

    How structure sensitive parameters derived from hysteresis loops can provide nondestructive information about the evolution of the microstructure of cold rolled low carbon steel as a result of recovery and recrystallization processes during the annealing is shown. The coercive field, remanent induction and hysteresis losses can be used to monitor the decrease in the dislocation density during recovery. These parameters are also influenced by the average grain refinement that takes place during recrystallization, which compensates the variation produced by the annihilation of dislocations during recrystallization. The maximum of the induction and of the relative differential permeability are shown to be very sensitive to the onset and to the monitoring of the recrystallization, respectively. The correlations between coercive field and remanent induction and hysteresis losses can also be used to distinguish between recovery and recrystallization

  13. Effects of deformation and boron on microstructure and continuous cooling transformation in low carbon HSLA steels

    Energy Technology Data Exchange (ETDEWEB)

    Jun, H.J. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kang, J.S. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Seo, D.H. [Technical Research Laboratories, POSCO, Pohang 545-090 (Korea, Republic of); Kang, K.B. [Technical Research Laboratories, POSCO, Pohang 545-090 (Korea, Republic of); Park, C.G. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)]. E-mail: cgpark@postech.ac.kr

    2006-04-25

    The continuous-cooling-transformation (CCT) diagram and continuous cooled microstructure were investigated for low carbon (0.05 wt.% C) high strength low alloy steels with/without boron. Microstructures observed in continuous cooled specimens were composed of pearlite, quasi-polygonal ferrite, granular bainite, acicular ferrite, bainitic ferrite, lower bainite, and martensite depending on cooling rate and transformation temperature. A rapid cooling rate depressed the formation of pearlite and quasi-polygonal ferrite, which resulted in higher hardness. However, hot deformation slightly increased transformation start temperature, and promoted the formation of pearlite and quasi-polygonal ferrite. Hot deformation also strongly promoted the acicular ferrite formation which did not form under non-deformation conditions. Small boron addition effectively reduced the formation of pearlite and quasi-polygonal ferrite and broadened the cooling rate region for bainitic ferrite and martensite.

  14. Effect of Asymmetric Rolling on Plastic Anisotropy of Low Carbon Steels during Simple Shear Tests

    International Nuclear Information System (INIS)

    Gracio, J. J.; Vincze, G.; Panigrahi, B. B.; Kim, H. J.; Barlat, F.; Rauch, E. F.; Yoon, J. W.

    2010-01-01

    Simple shear tests are performed on low carbon steel pre-deformed in conventional, asymmetric and orthogonal-asymmetric rolling. The simple-shear tests were carried out at 0 deg. , 45 deg. and 135 deg. with respect to the previous rolling direction. For a reduction ratio of 15%, a transient stagnation in the hardening rate is observed at reloading for all changes in strain path. The shear stress level, the hardening rate and extent of the plateau appear to be insensitive to the preliminary applied rolling conditions. After a reduction ratio of 50%, plastic instability was detected at reloading for all the changes of strain path and rolling conditions studied. A specific heat treatment was then designed allowing the material to become ductile after rolling while retaining the fine microstructure and therefore the high strength. Promising results were obtained essentially for 45 deg. shear tests.

  15. Diffusion bonding of commercially pure titanium to low carbon steel using a silver interlayer

    International Nuclear Information System (INIS)

    Atasoy, Evren; Kahraman, Nizamettin

    2008-01-01

    Titanium and low carbon steel plates were joined through diffusion bonding using a silver interlayer at various temperatures for various diffusion times. In order to determine the strength of the resulting joints, tensile-shear tests and hardness tests were applied. Additionally, optical, scanning electron microscopy examinations and energy dispersive spectrometry elemental analyses were carried out to determine the interface properties of the joint. The work showed that the highest interface strength was obtained for the specimens joined at 850 deg. C for 90 min. It was seen from the hardness results that the highest hardness value was obtained for the interlayer material and the hardness values on the both sides of the interlayer decreased gradually as the distance from the joint increased. In energy dispersive spectrometry analyses, it was seen that the amount of silver in the interlayer decreased markedly depending on the temperature rise. In addition, increasing diffusion time also caused some slight decrease in the amount of silver

  16. Austenite reversion in low-carbon martensitic stainless steels – a CALPHAD-assisted review

    DEFF Research Database (Denmark)

    Niessen, Frank

    2018-01-01

    Low-carbon martensitic stainless steels with 11.5–16 wt-% Cr and martensite upon inter-critical annealing. The review treats...... the mechanisms governing the formation and stabilisation of reverted austenite and is assisted by the computation of phase equilibria. Literature data on Cr and Ni concentrations of the reverted austenite/martensite dual-phase microstructure are assessed with respect to predicted concentrations. Reasonable...... agreement was found for concentrations in martensite. Systematic excess of Cr in austenite of approx. 2 wt-% relative to calculations was suspected to originate from the growth of M23C6 with a coherent interface to austenite. Within large scatter, measured values of Ni in austenite were on average 2 wt...

  17. An X-ray diffraction study of corrosion products from low carbon steel

    International Nuclear Information System (INIS)

    Morales, A. L.

    2003-01-01

    It was found in earlier work a decrease in the corrosion rate from low carbon steel when it was subjected to the action of a combined pollutant concentration (SO 4 ''2-=10''-4 M+Cl=1.5x 10''-3 M). It was also found that large magnetic content of the rust was related to higher corrosion rates. In the present study corrosion products are further analyzed by means of X-ray diffraction to account for composition changes during the corrosion process. it is found that lepidocrocite and goethite are the dominant components for the short-term corrosion in all batches considered while for log-term corrosion lepidocrite and goethite dominates if the corrosion rates is low and magnetite dominates if the corrosion rate is high. The mechanism for decreasing the corrosion rate is related to the inhibition of magnetite production at this particular concentration. (Author) 15 refs

  18. Application of Moessbauer effect to the study of austenite retained in low carbon steels

    International Nuclear Information System (INIS)

    Azevedo, A.L.T. de; Silva, E.G. da

    1979-01-01

    Moessbauer effect measurements were performed in two samples of low carbon, low alloy steels, one with a bainite granular microstructure and the other a martensitic one. The concentration of the retained austenite was determined in both samples by Moessbauer spectrometry and X radiation, a very good agreement for the sample with a greater austenite content having been observed. From the assumption that the carbon atoms in the f.c.c. matrix repel one another due to Coulomb interactions, giving origin to quadrupolar interactions, it was possible to determine carbon concentration in the MA (Martensite Austenite) components of bainite, the results being in good agreement with the one obtained from metallographic considerations. (I.C.R.) [pt

  19. Strong tough low-carbon bainite structural steels exposed to heat treatment and mechanical working

    International Nuclear Information System (INIS)

    Lauprecht, W.; Imgrund, H.; Coldren, P.

    1975-01-01

    A review of results of studying the mechanical properties and structure of extremely strong construction low-pearlite and pearlite-free steels subjected to thermomechanical processing (TMP) is presented. The development of TMP of low-pearlite and pearlite-free steels has led to creation of steel of the following composition: 0.06% of C; 1.8% of Mn; 0.3% of Mo; 0.05-0.09% of Nb. Depending on the kind of TMP the most important parameters of which are the temperature of the termination of rolling and the total deformation below 900 deg C, transformation in these steels occurs partially or completely in the intermediate domain. The increased density of dislocations of beinite structure affects substantially the increase in the yield limit. High degrees of squeezing at temperatures below 870 deg C promote formation of ferrite nuclei. The laboratory rolling demonstrates that by selecting the conditions of TMP one can control the mechanical properties of a steel. The sheets of 13 mm thick allow to obtain the guaranteed values of the yield limit of 70 kgf/mm 2 the transition temperature T 50 = -25 deg C, whereas after rolling under different conditions the low-temperature limit of cold shortness is - 125 deg C, and the yield limit - 45 kgf/mm 2 . As followed from the estimate of numerous industrial experiments, with sheets 20 mm thick in hot-rolled state one can obtain the yield limit no less than 50 kgf/mm 2 . On rolling mills that make possible to produce large deformation at low temperature these values can be increased. For instance, with sheets 30 mm thick one can obtain the yield limit of 56 kgf/mm 2 and the transition temperature of - 60 deg C. The dependence of the yield limit on the holding time in steel tempering is given. The steel possesses a considerable reserve of the increase of strength due to dispersion hardening, which after tempering at 600-625 deg C constitutes 8-12 kgf/mm 2 . Because of low carbon content, this steel is characterized by good

  20. Nb(C,N) precipitation kinetics in the bainite region of a low-carbon Nb-microalloyed steel

    International Nuclear Information System (INIS)

    Park, J.S.; Lee, Y.K.

    2007-01-01

    Nb(C,N) precipitation in the bainite region (580-660 deg. C) of a low-carbon Nb-microalloyed steel was investigated by electrical resistivity and transmission electron microscopy. Nb(C,N) particles started precipitating after 100-200 s at isothermal temperatures after bainite transformation and cementite formation, and precipitation finished in 1000-2000 s. The precipitation-time-temperature diagram of Nb(C,N) in the bainite region of a low-carbon microalloyed steel was a type of C-curve, with a nose temperature of about 615 deg. C

  1. Conversion electron Moessbauer study of low carbon steel polarized in aqueous sulfate solution containing sulfite in low concentration

    International Nuclear Information System (INIS)

    Vertes, Cs.; Lakatos-Varsanyi, M.; Vertes, A.; Kuzmann, E.; Meisel, W.; Guetlich, P.

    1992-01-01

    The passivation of low carbon steel was studied in aqueous solution of 0.5 M Na 2 SO 4 +0.001 M NaHSO 3 at pH=3.5 and 6.5. The found major components at pH=3.5 were: γ-FeOOH and Fe 3 C, and also FeSO 4 .H 2 O could be identified on the surface of the low carbon steel as a minor component. At pH=6.5, the passive film contained only amorphous iron(III)-oxide or oxyhydroxide. (orig.)

  2. INFLUENCE OF STRUCTURAL PARAMETERS OF LOW-CARBON STEEL ON ELECTRIC ARC BURNING

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2017-10-01

    Full Text Available Purpose. The article is aimed to evaluate the influence of structural parameters of low-carbon steel on arcing process. Methodology. The values of the micro- and substructure characteristics of the electrode wire metal were changed by varying the parameters of heat treatment and cold deformation by drawing. The degree of plastic deformation was obtained by drawing blanks from different initial diameter to final dimension of 1 mm. The thermal treatment was carried out in electric chamber furnace of the SNOL-1,6.2,5.1/11-IZ type. The temperature was measured by chromel-alumel thermocouple and the electromotive force was determined using the DC potentiometer. In order to obtain the substructure of different dispersion degree the steel (after quenching from temperatures and tempering at 650°C for 1 hour was subjected to cold drawing to reduction 17 – 80%. To form structure with different ferrite grain size the steel after drawing was annealed at 680°C for 1 hour. The microstructure was examined under a light and electron transmission microscope UEMV-100K at the accelerating voltage 100 kV. The grain and subgrain sizes were evaluated using the methodologies of quantitative metallography. A welding converter of the PSG-500 type was used to study the arc welding process of direct and reverse polarities. Findings. The experimentally detected value of the welding current, which depends on the degree of deformation during wire drawing, under conditions of stable arc burning of direct polarity is about an order of magnitude lower than the calculated value. Similar difference was found for the arc of reverse polarity: the experimental value of the welding current is 5...6 times less than the calculated value. Dependence analysis shows that, regardless of the polarity of the welding arc, a good enough agreement between the calculated and experimental values of the welding current is limited to deformations of 60%. For deformation degrees of more than 60

  3. Effect of Heat Input on Geometry of Austenitic Stainless Steel Weld Bead on Low Carbon Steel

    Science.gov (United States)

    Saha, Manas Kumar; Hazra, Ritesh; Mondal, Ajit; Das, Santanu

    2018-05-01

    Among different weld cladding processes, gas metal arc welding (GMAW) cladding becomes a cost effective, user friendly, versatile method for protecting the surface of relatively lower grade structural steels from corrosion and/or erosion wear by depositing high grade stainless steels onto them. The quality of cladding largely depends upon the bead geometry of the weldment deposited. Weld bead geometry parameters, like bead width, reinforcement height, depth of penetration, and ratios like reinforcement form factor (RFF) and penetration shape factor (PSF) determine the quality of the weld bead geometry. Various process parameters of gas metal arc welding like heat input, current, voltage, arc travel speed, mode of metal transfer, etc. influence formation of bead geometry. In the current experimental investigation, austenite stainless steel (316) weld beads are formed on low alloy structural steel (E350) by GMAW using 100% CO2 as the shielding gas. Different combinations of current, voltage and arc travel speed are chosen so that heat input increases from 0.35 to 0.75 kJ/mm. Nine number of weld beads are deposited and replicated twice. The observations show that weld bead width increases linearly with increase in heat input, whereas reinforcement height and depth of penetration do not increase with increase in heat input. Regression analysis is done to establish the relationship between heat input and different geometrical parameters of weld bead. The regression models developed agrees well with the experimental data. Within the domain of the present experiment, it is observed that at higher heat input, the weld bead gets wider having little change in penetration and reinforcement; therefore, higher heat input may be recommended for austenitic stainless steel cladding on low alloy steel.

  4. Effect of B and B + Nb on the bainitic transformation in low carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Kangying, E-mail: kangying.zhu@arcelormittal.com [ArcelorMittal Maizieres, Research and Development, BP 30320, 57283 Maizieres-les-Metz Cedex (France); Oberbillig, Carla, E-mail: carla.oberbillig@arcelormittal.com [ArcelorMittal Maizieres, Research and Development, BP 30320, 57283 Maizieres-les-Metz Cedex (France); Musik, Celine, E-mail: celine.musik@arcelormittal.com [ArcelorMittal Maizieres, Research and Development, BP 30320, 57283 Maizieres-les-Metz Cedex (France); Loison, Didier, E-mail: didier.loison@arcelormittal.com [ArcelorMittal Maizieres, Research and Development, BP 30320, 57283 Maizieres-les-Metz Cedex (France); Iung, Thierry, E-mail: thierry.iung@arcelormittal.com [ArcelorMittal Maizieres, Research and Development, BP 30320, 57283 Maizieres-les-Metz Cedex (France)

    2011-05-15

    Research highlights: {yields} B retards slightly the bainite transformation kinetics. {yields} Combined addition of B + Nb delayed dramatically bainite transformation kinetics. {yields} B refines the microstructure and promotes lath morphology of bainite. {yields} Larger packets of laths and longer laths are observed in the B + Nb steel. {yields} More free boron/finer borocarbide precipitates on {gamma} grain boundaries in B + Nb steel. - Abstract: Development of new, advanced high and ultra-high strength bainitic steels requires the selection of the optimum balance of bainite promoting elements allowing the production of the desired bainitic microstructure over a wide range of cooling rates. The addition of boron or a combined addition of boron and niobium is well known to retard strongly the polygonal ferrite formation but very little knowledge has been acquired on the bainitic transformation. Therefore, the purpose of this study is to investigate the influence of boron and boron plus niobium on the bainite transformation kinetics, microstructural evolution and mechanical properties in a low carbon steel (Fe-0.05C-1.49Mn-0.30Si). Isothermal and continuous cooling transformation diagrams were determined and followed by a detailed quantitative characterisation of the bainite microstructure and morphology using complementary advanced metallographic techniques (FEG-SEM-EBSD, SIMS and TEM). The relationship between microstructure and hardness has been evaluated. Finally, results of SIMS and TEM analyses coupled with microstructural investigations enable to propose a mechanism to explain the effect of the synergy between boron and niobium on the bainitic transformation and the resultant microstructure.

  5. Effect of B and B + Nb on the bainitic transformation in low carbon steels

    International Nuclear Information System (INIS)

    Zhu Kangying; Oberbillig, Carla; Musik, Celine; Loison, Didier; Iung, Thierry

    2011-01-01

    Research highlights: → B retards slightly the bainite transformation kinetics. → Combined addition of B + Nb delayed dramatically bainite transformation kinetics. → B refines the microstructure and promotes lath morphology of bainite. → Larger packets of laths and longer laths are observed in the B + Nb steel. → More free boron/finer borocarbide precipitates on γ grain boundaries in B + Nb steel. - Abstract: Development of new, advanced high and ultra-high strength bainitic steels requires the selection of the optimum balance of bainite promoting elements allowing the production of the desired bainitic microstructure over a wide range of cooling rates. The addition of boron or a combined addition of boron and niobium is well known to retard strongly the polygonal ferrite formation but very little knowledge has been acquired on the bainitic transformation. Therefore, the purpose of this study is to investigate the influence of boron and boron plus niobium on the bainite transformation kinetics, microstructural evolution and mechanical properties in a low carbon steel (Fe-0.05C-1.49Mn-0.30Si). Isothermal and continuous cooling transformation diagrams were determined and followed by a detailed quantitative characterisation of the bainite microstructure and morphology using complementary advanced metallographic techniques (FEG-SEM-EBSD, SIMS and TEM). The relationship between microstructure and hardness has been evaluated. Finally, results of SIMS and TEM analyses coupled with microstructural investigations enable to propose a mechanism to explain the effect of the synergy between boron and niobium on the bainitic transformation and the resultant microstructure.

  6. Raising the Corrosion Resistance of Low-Carbon Steels by Electrolytic-Plasma Saturation with Nitrogen and Carbon

    Science.gov (United States)

    Kusmanov, S. A.; Grishina, E. P.; Belkin, P. N.; Kusmanova, Yu. V.; Kudryakova, N. O.

    2017-05-01

    Structural features of the external oxide layer and internal nitrided, carbonitrided and carburized layers in steels 10, 20 and St3 produced by the method of electrolytic plasma treatment are studied. Specimens of the steels are tested for corrosion in a naturally aerated 1-N solution of sodium chloride. The condition of the metal/sodium chloride solution interface is studied by the method of electrochemical impedance spectroscopy. It is shown that the corrosion resistance of low-carbon steels can be raised by anode electrolytic-plasma saturation with nitrogen and carbon. Recommendations are given on the choice of carbonitriding modes for structural steels.

  7. Microstructure and failure behavior of dissimilar resistance spot welds between low carbon galvanized and austenitic stainless steels

    International Nuclear Information System (INIS)

    Marashi, P.; Pouranvari, M.; Amirabdollahian, S.; Abedi, A.; Goodarzi, M.

    2008-01-01

    Resistance spot welding was used to join austenitic stainless steel and galvanized low carbon steel. The relationship between failure mode and weld fusion zone characteristics (size and microstructure) was studied. It was found that spot weld strength in the pullout failure mode is controlled by the strength and fusion zone size of the galvanized steel side. The hardness of the fusion zone which is governed by the dilution between two base metals, and fusion zone size of galvanized carbon steel side are dominant factors in determining the failure mode

  8. Effect of rare earth and titanium additions on the microstructures and properties of low carbon Fe-B cast steel

    International Nuclear Information System (INIS)

    Fu Hanguang; Xiao Qiang; Kuang Jiacai; Jiang Zhiqiang; Xing Jiandong

    2007-01-01

    A new type of wear resistant low carbon Fe-B cast steel with granular borides can be obtained by alloying with titanium and cerium rare earth (RE). As a result, the as-cast eutectic boride structures of Fe-B cast steel are greatly refined and a blocky, less interconnected boride network is obtained from continuous ledeburite. After heat treatment, the boride eutectic in the modified Fe-B cast steel is in the form of a granular boride structure that appears to be isolated particles The guide rollers made of modified low carbon Fe-B cast steel show excellent wear resistance and thermal fatigue resistance in high speed wire mills

  9. Optimization of cladding parameters for resisting corrosion on low carbon steels using simulated annealing algorithm

    Science.gov (United States)

    Balan, A. V.; Shivasankaran, N.; Magibalan, S.

    2018-04-01

    Low carbon steels used in chemical industries are frequently affected by corrosion. Cladding is a surfacing process used for depositing a thick layer of filler metal in a highly corrosive materials to achieve corrosion resistance. Flux cored arc welding (FCAW) is preferred in cladding process due to its augmented efficiency and higher deposition rate. In this cladding process, the effect of corrosion can be minimized by controlling the output responses such as minimizing dilution, penetration and maximizing bead width, reinforcement and ferrite number. This paper deals with the multi-objective optimization of flux cored arc welding responses by controlling the process parameters such as wire feed rate, welding speed, Nozzle to plate distance, welding gun angle for super duplex stainless steel material using simulated annealing technique. Regression equation has been developed and validated using ANOVA technique. The multi-objective optimization of weld bead parameters was carried out using simulated annealing to obtain optimum bead geometry for reducing corrosion. The potentiodynamic polarization test reveals the balanced formation of fine particles of ferrite and autenite content with desensitized nature of the microstructure in the optimized clad bead.

  10. Production of Low-Carbon Magnetic Steel for the LHC Superconducting Dipole and Quadrupole Magnets

    CERN Document Server

    Bertinelli, F; Harlet, P; Peiro, G; Russo, A; Taquet, A

    2006-01-01

    In 1996 CERN negotiated a contract with Cockerill Sambre – ARCELOR Group for the supply of 50 000 tonnes of low-carbon steel for the LHC main magnets: this was the first contract to be placed for the project, and one of the single largest. In 2005 – after nine years of work – the contract is being successfully completed. This paper describes the steel specifically developed, known as MAGNETIL™, its manufacturing and quality control process, organization of production, logistics and contract follow-up. Extensive statistics have been collected relating to physical, mechanical and technological parameters. Specific attention is dedicated to magnetic measurements (coercivity and permeability) performed at both room and cryogenic temperatures, the equipment used and statistical results. Reference is also made to the resulting precision of the fineblanked laminations used for the magnet yoke. The technology transfer from the particle accelerator domain to industry is ongoing, for example for ...

  11. Surface Modification by Friction Stir Processing of Low-Carbon Steel: Microstructure Investigation and Wear Performance

    Science.gov (United States)

    Sattari, Behnoosh; Shamanian, Morteza; Salimijazi, Farshid; Salehi, Mehdi

    2018-02-01

    A low-carbon steel sheet with a thickness of 5 mm was subjected to friction stir processing (FSP) by one to four different passes. The microstructures of different regions were characterized using the optical microscopy and electron backscatter diffraction. The Vickers micro-harness was measured at the distance of 200 μm below the processed surfaces. The influence of pass numbers (PNs) on wear resistance was studied in terms of coefficients of friction (CoFs), weight losses and wear rates. SEM topographies of the worn surfaces were also studied to evaluate the wear mechanisms. Microstructure observations showed that Widmänstatten ferrite plates were formed in stir zones (SZs) and heat affected zones. As PN increased, these grains were widened due to the increment of the carbon diffusivity and lengthened because of the high heat input and microstructure anisotropy. Besides, increasing the PN causes increasing of the hardness and wear resistance, simultaneously. Specifically, the wear rate in the SZ was reduced from 2.8 × 10-2 mm3 m-1 in base metal to 0.3 × 10-2 mm3 m-1 in sample which was subjected to 4 FSP passes. However, variation in PN had no considerable effect on CoFs. Oxidative wear mechanism was observed on the worn surface of the steel and the FSPed samples while more debris was formed by increasing the PNs.

  12. Structural developments in un-stabilized ultra low carbon steel during warm deformation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, Rahul, E-mail: rahulunnikrishnannair@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Kumar, Amit, E-mail: chaudhary65amit@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Khatirkar, Rajesh K., E-mail: rajesh.khatirkar@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Shekhawat, Satish K., E-mail: satishshekhawat@gmail.com [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay (IITB), Powai, Mumbai 400076, Maharashtra (India); Sapate, Sanjay G., E-mail: sgsapate@yahoo.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India)

    2016-11-01

    In the present investigation, ultra low carbon steel samples were deformed in plane strain compression mode in a deformation simulator. The deformation was carried out at four different temperatures in the warm rolling region (293, 473, 673 and 873 K) upto 70% strain at two different strain rates (0.1/s and 1/s). Subsequently, all the deformed samples were fully recrystallized at 1073 K. Afterwards, all the deformed and fully recrystallized samples were subjected to detailed microstructural characterization using optical microscope, scanning electron microscope and electron backscattered diffraction. Bulk texture was measured for all the samples by X-ray diffraction. In-grain misorientation developments (kernel average misorientations) were estimated for the deformed γ-fibre (ND//<111>) and α-fibre (RD//<110>). Deformed γ-fibre showed an increase in in-grain misorientation at intermediate deformation temperatures. This increase was explained by using the plastic instability criterion. After complete recrystallization, the γ-fibre strengthened for deformation at lower temperatures (293 K and 473 K), while Goss texture developed for samples deformed at higher temperatures (673 K and 873 K). - Highlights: • ULC steel samples were deformed in near plane strain condition. • Microstructural developments were characterized using EBSD. • Increase in in-grain misorientation at intermediate deformation temperatures. • γ-fibre strengthened for low temperature deformation. • Goss texture developed for high temperature deformation.

  13. TEM Study of the Orientation Relationship Between Cementite and Ferrite in a Bainitic Low Carbon High Strength Low Alloy Steel

    OpenAIRE

    Illescas Fernandez, Silvia; Brown, A.P.; He, K.; Fernández, Javier; Guilemany Casadamon, Josep Maria

    2005-01-01

    Two different bainitic structures are observed in a steel depending on the sample heat treatment. The different types of bainitic structures exhibit different orientation relationships between cementite and the ferrite matrix. Upper bainite presents a Pitsch orientation relationship and lower bainite presents a Bagaryatski orientation relationship. Different heat treatments of low carbon HSLA steel samples have been studied using TEM in order to find the orientation relationshi...

  14. Prevention of burn-on defect on surface of hydroturbine blade casting of ultra-low-carbon refining stainless steel

    Directory of Open Access Journals (Sweden)

    Li Ling

    2008-08-01

    Full Text Available The burn-on sand is common surface defect encountered in CO2-cured silicate-bonded sand casting of hydroturbine blade of ultra-low-carbon martensitic stainless steel, its feature, causes and prevention measures are presented in this paper. Experiments showed that the burn-on defect is caused by oxidization of chromium in the molten steel at high temperature and can be effectively eliminated by using chromium-corundum coating.

  15. Study on microstructure and mechanical characteristics of low-carbon steel and ferritic stainless steel joints

    Energy Technology Data Exchange (ETDEWEB)

    Sarkari Khorrami, Mahmoud; Mostafaei, Mohammad Ali; Pouraliakbar, Hesam, E-mail: hpouraliakbar@alum.sharif.edu; Kokabi, Amir Hossein

    2014-07-01

    In this work, examinations on the microstructure and mechanical properties of plain carbon steel and AISI 430 ferritic stainless steel dissimilar welds are carried out. Welding is conducted in both autogenous and using ER309L austenitic filler rod conditions through gas tungsten arc welding process. The results indicate that fully-ferritic and duplex ferritic–martensitic microstructures are formed for autogenous and filler-added welds, respectively. Carbide precipitation and formation of martensite at ferrite grain boundaries (intergranular martensite) as well as grain growth occur in the heat affected zone (HAZ) of AISI 430 steel. It is found that weld heat input can strongly affect grain growth phenomenon along with the amount and the composition of carbides and intergranular martensite. Acquired mechanical characteristics of weld in the case of using filler metal are significantly higher than those of autogenous one. Accordingly, ultimate tensile strength (UTS), hardness, and absorbed energy during tensile test of weld metal are increased from 662 MPa to 910 MPa, 140 Hv to 385 Hv, and 53.6 J m{sup −3} to 79 J m{sup −3}, respectively by filler metal addition. From fracture surfaces, predominantly ductile fracture is observed in the specimen welded with filler metal while mainly cleavage fracture occurs in the autogenous weld metal.

  16. Modeling of roughness effect on hydrogen permeation in a low carbon steel

    Directory of Open Access Journals (Sweden)

    Carreño, J. A.

    2003-12-01

    Full Text Available A model is presented to evaluate the effect of the roughness and the profile of concentration of hydrogen in a low carbon steel. The model takes advantage of the Fick's Second Law, to predict the transport of hydrogen in the steel. The problem is treated as a variational one and its space solution is made numerically by means of the Finite Elements Method, while the temporal equation is solved via the Finite Differences Method, in order to determine the concentration profiles of Hydrogen in the steel and to quantify the roughness effect. Simultaneously, bipotentiostatic hydrogen permeation test were performed to evaluate the coefficient of mass transfer.

    El presente trabajo modela el efecto de la rugosidad y el perfil de concentración de hidrógeno en un acero, tomando como punto de partida la segunda ley de Fick para explicar el transporte de hidrógeno en el acero. El problema se trata como un problema variacional y su solución espacial se hace numéricamente por el Método de Elementos Finitos, mientras que la temporal por el Método de Diferencias Finitas, siendo estas las herramientas utilizadas para determinar los perfiles de concentración y cuantificar el efecto superficial presentado en este tipo de fenómeno. Además, a partir de la teoría se obtienen ecuaciones algebraicas que determinan el efecto que tiene la preparación superficial y el coeficiente de transferencia de masa con la permeación y concentración de hidrógeno en el acero.

  17. Determination of aluminium nitride or free nitrogen in low carbon steel

    International Nuclear Information System (INIS)

    Guetaz, V.; Soler, M.; Massardier, V.; Merlin, J.; Ravaine, D.

    2001-01-01

    As the aluminium nitrides play an important role in the manufacturing of steel sheets, a specific methodology was developed based on the thermoelectric power (TEP) technique, in order to determine the AIN nitrogen by an indirect method. The free nitrogen was determined and then the AIN nitrogen was calculated by the difference between the total nitrogen and the free nitrogen. Indeed, it is easier to determine the dissolved nitrogen, the content of which gradually decreases during the AIN precipitation, than the AIN nitrogen. A low carbon aluminium killed steel was employed with 580 ppm of aluminium and 50 ppm of nitrogen. A comparison of the results obtained by TEP with those obtained by other techniques (hot hydrogen extraction, electrochemical dissolution followed by a mineralization, electrochemical dissolution followed by a sodic decomposition and the Beeghly method) was conducted, in order to determine a reliable technique likely to quantify the amount of aluminium nitrides in aluminium killed steels. With these techniques, it is possible to determine either free nitrogen or precipitated nitrogen. From an experimental point of view, the precipitation kinetics of AIN was followed during an annealing performed at 973 K (700 C) by TEP and then different precipitation states of AIN were investigated to compare the different techniques: three annealing states (when no nitrogen, half the nitrogen and the total nitrogen has precipitated) and two soaking states (1403 and 1523 K). Thus, it was possible to compare states where the AIN precipitates are in various forms (different shapes, crystallographic structures, sizes, distributions in the matrix). This work showed that the quantification by TEP, hot hydrogen extraction and electrochemical dissolution followed by a mineralization seem reliable whereas the Beeghly method gives good results only for the precipitates formed at high temperatures. In contrast, the quantification by electrochemical dissolution followed by

  18. Mechanical properties and hot-rolled microstructures of a low carbon bainitic steel with Cu-P alloying

    International Nuclear Information System (INIS)

    Cui, W.F.; Zhang, S.X.; Jiang, Y.; Dong, J.; Liu, C.M.

    2011-01-01

    Highlights: → Mechanical properties and microstructures of low carbon bainite steel are examined. → Cu-P alloying promotes strengthening and uniform plastic deformation. → Cu-P alloying delays recovery process during rolling interval. → Lowering rolling temperature is favorable to increasing toughness. - Abstract: A low carbon bainitic steel with Cu-P alloying was developed. The new steel aims to meet the demand of high strength, high toughness and resistance to chloride ion corrosion for the components used in the environment of sea water and oceanic atmosphere. Mechanical properties of the steel were tested and strengthening and toughening mechanisms were analyzed by comparing hot-rolled microstructures of the low carbon bainitic steels with and without Cu-P alloying. The results show that Cu-P alloying provided strong solution strengthening with weak effect on ductility. The toughness loss caused by Cu-P alloying could be balanced by increasing the amount of martensite/remained austenite (M/A island) at lower finishing temperature. The static recovery process during rolling interval was delayed by the interaction of phosphorous, copper atoms with dislocations, which was favorable to the formation of bainitic plates. Super-fine Nb(C, N) particles precipitated on dislocations had coherency with bainite ferrite at 830 deg. C finishing temperature. Raising finishing temperature to 880 deg. C, Nb(C, N) particles were prone to coarsening and losing coherency. It was also found that no accurate lattice match relationship among retained austenite, martensite and bainite in granular bainitic microstructure.

  19. Mechanical properties and hot-rolled microstructures of a low carbon bainitic steel with Cu-P alloying

    Energy Technology Data Exchange (ETDEWEB)

    Cui, W.F., E-mail: wenfangcui@yahoo.com.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China); Zhang, S.X. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China); Technology Center of Laiwu Iron and Steel (Group) Co. Ltd., Laiwu 271104 (China); Jiang, Y. [School of Chemical Engineering, University of Queensland, Brisbane 4072 (Australia); Dong, J. [Technology Center of Laiwu Iron and Steel (Group) Co. Ltd., Laiwu 271104 (China); Liu, C.M. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China)

    2011-08-15

    Highlights: {yields} Mechanical properties and microstructures of low carbon bainite steel are examined. {yields} Cu-P alloying promotes strengthening and uniform plastic deformation. {yields} Cu-P alloying delays recovery process during rolling interval. {yields} Lowering rolling temperature is favorable to increasing toughness. - Abstract: A low carbon bainitic steel with Cu-P alloying was developed. The new steel aims to meet the demand of high strength, high toughness and resistance to chloride ion corrosion for the components used in the environment of sea water and oceanic atmosphere. Mechanical properties of the steel were tested and strengthening and toughening mechanisms were analyzed by comparing hot-rolled microstructures of the low carbon bainitic steels with and without Cu-P alloying. The results show that Cu-P alloying provided strong solution strengthening with weak effect on ductility. The toughness loss caused by Cu-P alloying could be balanced by increasing the amount of martensite/remained austenite (M/A island) at lower finishing temperature. The static recovery process during rolling interval was delayed by the interaction of phosphorous, copper atoms with dislocations, which was favorable to the formation of bainitic plates. Super-fine Nb(C, N) particles precipitated on dislocations had coherency with bainite ferrite at 830 deg. C finishing temperature. Raising finishing temperature to 880 deg. C, Nb(C, N) particles were prone to coarsening and losing coherency. It was also found that no accurate lattice match relationship among retained austenite, martensite and bainite in granular bainitic microstructure.

  20. Characterization of coarse bainite transformation in low carbon steel during simulated welding thermal cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Liangyun, E-mail: lanly@me.neu.edu.cn [School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819 (China); State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Kong, Xiangwei [School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819 (China); Qiu, Chunlin [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2015-07-15

    Coarse austenite to bainite transformation in low carbon steel under simulated welding thermal cycles was morphologically and crystallographically characterized by means of optical microscope, transmission electron microscope and electron backscattered diffraction technology. The results showed that the main microstructure changes from a mixture of lath martensite and bainitic ferrite to granular bainite with the increase in cooling time. The width of bainitic laths also increases gradually with the cooling time. For a welding thermal cycle with relatively short cooling time (e.g. t{sub 8/5} is 30 s), the main mode of variant grouping at the scale of individual prior austenite grains changes from Bain grouping to close-packed plane grouping with the progress of phase transformation, which results in inhomogeneous distribution of high angle boundaries. As the cooling time is increased, the Bain grouping of variants becomes predominant mode, which enlarges the effective grain size of product phase. - Highlights: • Main microstructure changes and the width of lath structure increases with cooling time. • Variant grouping changes from Bain zone to close-packed plane grouping with the transformation. • The change of variant grouping results in uneven distribution of high angle grain boundary. • Bain grouping is main mode for large heat input, which lowers the density of high angle boundary.

  1. Characterization of coarse bainite transformation in low carbon steel during simulated welding thermal cycles

    International Nuclear Information System (INIS)

    Lan, Liangyun; Kong, Xiangwei; Qiu, Chunlin

    2015-01-01

    Coarse austenite to bainite transformation in low carbon steel under simulated welding thermal cycles was morphologically and crystallographically characterized by means of optical microscope, transmission electron microscope and electron backscattered diffraction technology. The results showed that the main microstructure changes from a mixture of lath martensite and bainitic ferrite to granular bainite with the increase in cooling time. The width of bainitic laths also increases gradually with the cooling time. For a welding thermal cycle with relatively short cooling time (e.g. t 8/5 is 30 s), the main mode of variant grouping at the scale of individual prior austenite grains changes from Bain grouping to close-packed plane grouping with the progress of phase transformation, which results in inhomogeneous distribution of high angle boundaries. As the cooling time is increased, the Bain grouping of variants becomes predominant mode, which enlarges the effective grain size of product phase. - Highlights: • Main microstructure changes and the width of lath structure increases with cooling time. • Variant grouping changes from Bain zone to close-packed plane grouping with the transformation. • The change of variant grouping results in uneven distribution of high angle grain boundary. • Bain grouping is main mode for large heat input, which lowers the density of high angle boundary

  2. Characterization of thin Zn-Ni alloy coatings electrodeposited on low carbon steel

    International Nuclear Information System (INIS)

    El Hajjami, A.; Gigandet, M.P.; De Petris-Wery, M.; Catonne, J.C.; Duprat, J.J.; Thiery, L.; Raulin, F.; Pommier, N.; Starck, B.; Remy, P.

    2007-01-01

    The characteristics of initial layer formation in alkaline bath for Zn-Ni (12-15%) alloy electrodeposition on low carbon steel plates are detected in a nanometric thickness range by electron probe microanalysis (EPMA), with both bulk sample and thin film on substrate correction procedure, glow discharge optical emission spectroscopy (GDOES) and gracing incidence X-ray diffraction (GIXRD). The Zn-Ni coatings were elaborated using either intensiostatic or potentiostatic mode. A preferential deposition of Ni, in the initial thin layer, is detected by these analyses; according to EPMA and GDOES measurements, a layer rich in nickel at the interface substrate/deposit is observed (90 wt.% Ni) and approved by GIXRD; the thin layer of Ni formed in the first moments of electrolysis greatly inhibits the Zn deposition. The initial layer depends upon the relative ease of hydrogen and metal discharge and on the different substrate surfaces involved. The electrodeposition of zinc-nickel alloys in the first stage is a normal phenomenon of codeposition, whereby nickel - the more noble metal - is deposited preferentially

  3. Texture evolution during the recrystallization of a warm-rolled low-carbon steel

    International Nuclear Information System (INIS)

    Sanchez-Araiza, M.; Godet, S.; Jacques, P.J.; Jonas, J.J.

    2006-01-01

    The texture changes taking place during the recrystallization of a warm-rolled low-carbon steel were examined using electron backscattered diffraction. The deformation textures of the warm-rolled material are similar in shape to those of cold-rolled materials, but are somewhat more intense. The recrystallization textures resemble the deformation textures but with a more extended α fibre that includes the {1 1 3} orientation; the γ fibre extends to the {5 5 4} orientation. These two orientations are related to the {1 1 2} deformed grains by near 26 deg, rotations about selected axes. Nevertheless, both orientations appear in the early stages of recrystallization, an observation that does not support the oriented growth theory. The {1 1 1} orientations are the first to recrystallize while the α fibre is present until the end of recrystallization. It is finally consumed by all types of grains as well as by subgrain coalescence. The similarities in the growth rates for the {1 1 1} and random orientations and the late disappearance of the α fibre suggest that recrystallization takes place according to the high stored energy oriented nucleation concept

  4. Experiment on relationship between the magnetic gradient of low-carbon steel and its stress

    International Nuclear Information System (INIS)

    Jian Xingliang; Jian Xingchao; Deng Guoyong

    2009-01-01

    In geomagnetic field, a series of tensile experiments on the low-carbon steel sticks were carried out. A special homemade detector was used to measure the magnetic gradient on the material surface. The results showed that the relationship between the magnetic gradient and the stress varied with different conditions of measurement. There was no obvious correlation between the magnetic gradient and the tensile stress if the sample remained on the material test machine. If the sample was taken off from the machine, the measured magnetic gradient was linear with the prior maximum stress. In Nanjing, PR China, a place of 32 o N latitude, the slope of the linear relationship was about 67 (uT/m)/MPa. This offered a new method of non-destructive stress testing by measuring the magnetic gradient on the ferromagnetic component surface. The prior maximum applied stress of the sample could be tested by measuring the present surface magnetic gradient. Actually this phenomenon was the metal magnetic memory (MMM). The magnetic gradient near the stress concentration zone of the sample, the necking point, was much larger than other area. Thus, the hidden damage in the ferromagnetic component could be detected early by measuring the magnetic gradient distribution on its surface. In addition, the magnetic memory signal gradually weakened as the sample was taken off and laid aside. Therefore, it was effective for a given period of time to detect the stress or stress concentration based on the MMM testing.

  5. Electro-Chemical Behavior of Low Carbon Steel Under H2S Influence

    Science.gov (United States)

    Zaharia, M. G.; Stanciu, S.; Cimpoesu, R.; Nejneru, C.; Savin, C.; Manole, V.; Cimpoeșu, N.

    2017-06-01

    Abstract A commercial low carbon steel material (P265GH) with application at industrial scale for natural gas delivery and transportation systems was analyzed in H2S atmosphere. The article proposed a new experimental cell in order to establish the behavior of the material in sulfur contaminated environment. In most of the industrial processes for gas purification the corrosion rate is speed up by the presence of S (sulfur) especially as ions or species like H2S. The H2S (hydrogen sulfide) is, beside a very toxic compound, a very active element in the acceleration of metallic materials deterioration especially in complex solicitations like pressure and temperature in the same time. For experiments we used a three electrodes cell with Na2SO4 + Na2S solution at pH 3 at room temperature (∼ 25 °C) to realize EIS (electrochemical impedance spectroscopy) and potentio-dynamic polarization experiments. Scanning electron microscopy and X-ray dispersive energy spectroscopy were used to characterize the metallic material surface exposed to experimental environment.

  6. Development of Low Carbon Niobium Bearing High Strength F-B Dual Phase Steel with High Hole Expansion Property

    Science.gov (United States)

    Zhang, Lin; Xia, Ming-sheng; Xiong, Zi-liu; Du, Yan-bing; Qiao, Zhi-ming; Zhang, Hong-bo

    In the study a low carbon niobium bearing high strength F-B dual phase automobile steel with high hole expansion property has been investigated. Steels of different chemical composition have been investigated by simulation experiments of controlled rolling and cooling process to study the influences of chemical elements, especially for C,Nb and Ti, and cooling pattern on the mechanical properties, flangeability and microstructure of strips. So-called 3-stages cooling pattern was adopted in simulation experiments, combining ultra fast cooling in first stage, air cooling in middle stage and fast cooling in the last stage, and at the end of run-out table the temperature of rolled pieces drop to below Bs point. Optical microstructure and SEM morphology have been observed. Results indicate that it is possible to obtain dual phase microstructure of polygonal ferrite plus bainite in adopting 3-stages cooling pattern. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling is effective to produce low carbon Nb bearing steel with high balance of strength-ductility-flangeability, in addition, higher carbon content of steel tend to be detrimental to flangeability of steel, due to much carbide precipitation at ferrite boundary. Based on the results of simulation experiments mill trial has been carried out and hot rolled high strength steel with tensile strength higher as 600Mpa and hole expansion ratio higher as 100% has been developed successfully.

  7. Nanoscale co-precipitation and mechanical properties of a high-strength low-carbon steel

    International Nuclear Information System (INIS)

    Mulholland, Michael D.; Seidman, David N.

    2011-01-01

    Nanoscale co-precipitation in a novel high-strength low-carbon steel is studied in detail after isothermal aging. Atom-probe tomography is utilized to quantify the co-precipitation of co-located Cu precipitates and M 2 C (M is any combination of Cr, Mo, Fe, or Ti) carbide strengthening precipitates. Coarsening of Cu precipitates is offset by the nucleation and growth of M 2 C carbide precipitate, resulting in the maintenance of a yield strength of 1047 ± 7 MPa (152 ± 1 ksi) for as long as 320 h of aging time at 450 deg. C. Impact energies of 153 J (113 ± 6 ft-lb) and 144 J (106 ± 2 ft-lb) are measured at -30 deg. C and -60 deg. C, respectively. The co-location of Cu and M 2 C carbide precipitates results in non-stationary-state coarsening of the Cu precipitates. Synchrotron-source X-ray diffraction studies reveal that the measured 33% increase in impact toughness after aging for 80 h at 450 deg. C is due to dissolution of cementite, Fe 3 C, which is the source of carbon for the nucleation and growth of M 2 C carbide precipitates. Less than 1 vol.% austenite is observed for aging treatments at temperatures less than 600 deg. C, suggesting that transformation-induced plasticity does not play a significant role in the toughness of specimens aged at temperatures less than 600 deg. C. Aging treatments at temperatures greater than 600 deg. C produce more austenite, in the range 2-7%, but at the expense of yield strength.

  8. Microstructure and Mechanical Properties of Inconel 625 Alloy on Low Carbon Steel by Heat Treatment after Overlay Welding

    International Nuclear Information System (INIS)

    Kim, Seungpil; Jang, Jaeho; Kim, Jungsoo; Kim, Byung Jun; Sohn, Keun Yong; Nam, Dae-Geun

    2016-01-01

    Overlay welding technique is one of methods used to improve metal mechanical properties such as strength, toughness and corrosion resistance. Generally, Inconel 625 alloy is used for overlay welding layer on low carbon steels for economic consideration. However, the method produces some problems in the microstructure of the cast structure and some defects, caused by the elevated temperatures of the overlay process. To resolve these problems, heat treatments are required. In this study, Inconel 625 alloy was welded on a low carbon steel by the overlay welding process to investigate the resulting microstructure and mechanical properties. A double heat treatment was performed to improve the mechanical properties of the welding and substrate layers. It was found that Inconel 625 alloy had an austenite microstructure after the first heat treatment, but the low carbon steel had a ferrite-pearlite microstructure after the second heat treatment. After the double heat treatment, the sample showed the optimum hardness because of grain refinement and homogenization of the microstructure.

  9. Microstructure and Mechanical Properties of Inconel 625 Alloy on Low Carbon Steel by Heat Treatment after Overlay Welding

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungpil; Jang, Jaeho; Kim, Jungsoo; Kim, Byung Jun; Sohn, Keun Yong; Nam, Dae-Geun [Korea Institute of Industrial Technology, Busan (Korea, Republic of)

    2016-08-15

    Overlay welding technique is one of methods used to improve metal mechanical properties such as strength, toughness and corrosion resistance. Generally, Inconel 625 alloy is used for overlay welding layer on low carbon steels for economic consideration. However, the method produces some problems in the microstructure of the cast structure and some defects, caused by the elevated temperatures of the overlay process. To resolve these problems, heat treatments are required. In this study, Inconel 625 alloy was welded on a low carbon steel by the overlay welding process to investigate the resulting microstructure and mechanical properties. A double heat treatment was performed to improve the mechanical properties of the welding and substrate layers. It was found that Inconel 625 alloy had an austenite microstructure after the first heat treatment, but the low carbon steel had a ferrite-pearlite microstructure after the second heat treatment. After the double heat treatment, the sample showed the optimum hardness because of grain refinement and homogenization of the microstructure.

  10. Characteristics of martensite as a function of the Ms temperature in low-carbon armour steel plates

    International Nuclear Information System (INIS)

    Maweja, Kasonde; Stumpf, Waldo; Berg, Nic van der

    2009-01-01

    The microstructure, morphology, crystal structure and surface relief of martensite in a number of experimental armour steel plates with different M s temperatures were analysed. Atomic force microscopy, thin foil transmission electron microscopy and scanning electron microscopy allowed the identification of three groups of low-carbon martensitic armour steels. The investigation showed that the size of individual martensite products (plates or packets, laths or blocks) increases as the M s temperature increases. Comparison of ballistic performances suggests that the morphology (plate or lath) and size of the individual martensite products dictate the effective 'grain size' in resisting fracture or perforation due to ballistic impact.

  11. Influence of mechanical stress level in preliminary stress-corrosion testing on fatigue strength of a low-carbon steel

    International Nuclear Information System (INIS)

    Aleskerova, S.A.; Pakharyan, V.A.

    1978-01-01

    Effect of corrosion and mechanical factors of preliminary stress corrosion of a metal in its fatigue strength, has been investigated. Smooth cylindrical samples of 20 steel have been tested. Preliminary corrosion under stress has been carried out under natural sea conditions. It is shown that mechanical stresses in the case of preliminary corrosion affect fatigue strength of low-carbon steels, decreasing the range of limited durability and fatigue limit. This effect increases with the increase of stress level and agressivity of corrosive medium

  12. Characteristics of martensite as a function of the M{sub s} temperature in low-carbon armour steel plates

    Energy Technology Data Exchange (ETDEWEB)

    Maweja, Kasonde, E-mail: mawejak@yahoo.fr [Council for Scientific and Industrial Research, CSIR, Materials Science and Manufacturing, PO Box 395, Pretoria 0001 (South Africa); Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002 (South Africa); Stumpf, Waldo [Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002 (South Africa); Berg, Nic van der [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

    2009-08-30

    The microstructure, morphology, crystal structure and surface relief of martensite in a number of experimental armour steel plates with different M{sub s} temperatures were analysed. Atomic force microscopy, thin foil transmission electron microscopy and scanning electron microscopy allowed the identification of three groups of low-carbon martensitic armour steels. The investigation showed that the size of individual martensite products (plates or packets, laths or blocks) increases as the M{sub s} temperature increases. Comparison of ballistic performances suggests that the morphology (plate or lath) and size of the individual martensite products dictate the effective 'grain size' in resisting fracture or perforation due to ballistic impact.

  13. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Forcey, K S; Ross, D K [Birmingham Univ. (UK). Dept. of Physics; Iordanova, I A [Sofia Univ. (Bulgaria). Dept. of Solid State Physics

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.).

  14. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    International Nuclear Information System (INIS)

    Forcey, K.S.; Ross, D.K.; Iordanova, I.A.

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.)

  15. Understanding dual precipitation strengthening in ultra-high strength low carbon steel containing nano-sized copper precipitates and carbides

    Science.gov (United States)

    Phaniraj, M. P.; Shin, Young-Min; Jung, Woo-Sang; Kim, Man-Ho; Choi, In-Suk

    2017-07-01

    Low carbon ferritic steel alloyed with Ti, Mo and Cu was hot rolled and interrupt cooled to produce nano-sized precipitates of copper and (Ti,Mo)C carbides. The steel had a tensile strength of 840 MPa, an increase in yield strength of 380 MPa over that of the plain carbon steel and reasonable ductility. Transmission electron microscopy and small angle neutron scattering were used to characterize size and volume fraction of the precipitates in the steels designed to form only copper precipitates and only (Ti,Mo)C carbides. The individual and combined precipitation strengthening contributions was calculated using the size and volume fraction of precipitates and compared with the measured values.

  16. Microstructure and Property of Mn-Nb-B Low Carbon Bainite High Strength Steel Under Ultra-fast Cooling

    Directory of Open Access Journals (Sweden)

    WANG Bing-xing

    2016-07-01

    Full Text Available Using the Mn-Nb-B low carbon bainite high strength steel with the reducing production technology as the research target, the deformation behavior and phase transformation behavior were studied by the thermal simulation testing machine. Combining with the characteristics of the medium and heavy plate production line, the controlled rolling and controlled cooling technology based on ultra-fast cooling were designed to produce low cost high strength construction machinery steel with superior comprehensive mechanical properties. The strengthening mechanisms such as grain refinement strengthening, precipitation strengthening are effective to produce the Mn-Nb-B low carbon bainite high strength steel. The yield strength and tensile strength of the product reach to 678MPa and 756 MPa respectively, the elongation A50 is 33% and the impact energy at -20℃ is 261J. The microstructure of the steel is composed of granular bainite, acicular ferrite and lath bainite. A large number of fine, point, granular M/A constituents and dislocation structures dispersively distributed inside the matrix, and also tiny and dispersed (Nb,Ti (C,N precipitates are observed by transmission electron microscopy.

  17. Optimization of chemical compositions in low-carbon Al-killed enamel steel produced by ultra-fast continuous annealing

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Futao, E-mail: dongft@sina.com [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Du, Linxiu; Liu, Xianghua [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Xue, Fei [College of Electrical Engineering, Hebei United University, Tangshan 063000 (China)

    2013-10-15

    The influence of Mn,S and B contents on microstructural characteristics, mechanical properties and hydrogen trapping ability of low-carbon Al-killed enamel steel was investigated. The materials were produced and processed in a laboratory and the ultra-fast continuous annealing processing was performed using a continuous annealing simulator. It was found that increasing Mn,S contents in steel can improve its hydrogen trapping ability which is attributed by refined ferrite grains, more dispersed cementite and added MnS inclusions. Nevertheless, it deteriorates mechanical properties of steel sheet. Addition of trace boron results in both good mechanical properties and significantly improved hydrogen trapping ability. The boron combined with nitrogen segregating at grain boundaries, cementite and MnS inclusions, provides higher amount of attractive hydrogen trapping sites and raises the activation energy for hydrogen desorption from them. - Highlights: • We study microstructures and properties in low-carbon Al-killed enamel steel. • Hydrogen diffusion coefficients are measured to reflect fish-scale resistance. • Manganese improves hydrogen trapping ability but decrease deep-drawing ability. • Boron improves both hydrogen trapping ability and deep-drawing ability. • Both excellent mechanical properties and fish-scale resistance can be matched.

  18. Corrosion resistance of Ultra-Low-Carbon 19% Cr-11% Ni stainless steel for nuclear fuel reprocessing plants in nitric acid

    International Nuclear Information System (INIS)

    Ariga, Tamako; Takagi, Yoshio; Inazumi, Toru; Masamura, Katsumi; Sukekawa, M.

    1995-01-01

    An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author)

  19. Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

    Science.gov (United States)

    Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

    2017-01-01

    TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

  20. Comparison of the monotonic and cyclic mechanical properties of ultrafine-grained low carbon steels processed by continuous and conventional equal channel angular pressing

    International Nuclear Information System (INIS)

    Niendorf, T.; Böhner, A.; Höppel, H.W.; Göken, M.; Valiev, R.Z.; Maier, H.J.

    2013-01-01

    Highlights: ► UFG low-carbon steel was successfully processed by continuous ECAP-Conform. ► Continuously processed UFG steel shows high performance. ► High monotonic strength and good ductility. ► Microstructural stability under cyclic loading in the LCF regime. ► Established concepts can be used for predicting the properties. - Abstract: In the current study the mechanical properties of ultra-fine grained low carbon steel processed by conventional equal channel angular pressing and a continuous equal channel angular pressing-Conform process were investigated. Both monotonic and cyclic properties were determined for the steel in either condition and found to be very similar. Microstructural analyses employing electron backscatter diffraction were used for comparison of the low carbon steels processed by either technique. Both steels feature very similar grain sizes and misorientation angle distributions. With respect to fatigue life the low carbon steel investigated shows properties similar to ultra-fine grained interstitial-free steel processed by conventional equal channel angular pressing, and thus, the general fatigue behavior can be addressed following the same routines as proposed for interstitial-free steel. In conclusion, the continuously processed material exhibits very promising properties, and thus, equal channel angular pressing-Conform is a promising tool for production of ultra-fine grained steels in a large quantity

  1. The Effect of Prestrain Temperature on Kinetics of Static Recrystallization, Microstructure Evolution, and Mechanical Properties of Low Carbon Steel

    Science.gov (United States)

    Akbari, Edris; Karimi Taheri, Kourosh; Karimi Taheri, Ali

    2018-05-01

    In this research, the samples of a low carbon steel sheet were rolled up to a thickness prestrain of 67% at three different temperatures consisted of room, blue brittleness, and subzero temperature. Microhardness, SEM, and tensile tests were carried out to evaluate the static recrystallization kinetics defined by the Avrami equation, microstructural evolution, and mechanical properties. It was found that the Avrami exponent is altered with change in prestrain temperature and it achieves the value of 1 to 1. 5. Moreover, it was indicated that prestraining at subzero temperature followed by annealing at 600 °C leads to considerable enhancement in tensile properties and kinetics of static recrystallization compared to room and blue brittleness temperatures. The prestraining at blue brittleness temperature followed by annealing treatment caused, however, a higher strength and faster kinetics compared with that at room temperature. It was concluded that although from the steel ductility point of view, the blue brittleness temperature is called an unsuitable temperature, but it can be used as prestraining temperature to develop noticeable combination of strength and ductility in low carbon steel.

  2. Relationship Between Bake Hardening, Snoek-Köster and Dislocation-Enhanced Snoek Peaks in Coarse Grained Low Carbon Steel

    Directory of Open Access Journals (Sweden)

    Li Weijuan

    2016-09-01

    Full Text Available In the present work, specimens prepared from coarse grained low carbon steel with different prestrains were baked and then, their bake hardening (BH property and internal friction were determined. TEM was used to characterize the dislocation structure in BH treated samples. The measurements of internal friction in prestrained samples and baked samples were carried out using a multifunctional internal friction apparatus. The results indicate that, in coarse grained low carbon steel, the bake hardening properties (BH values were negative, which were increased by increasing the prestrain from 2 to 5%, and then were decreased by increasing the prestrain from 5 to 10%. In the specimen with prestrain 5%, the BH value reached the maximum value and the height of Snoek-Köster peak was observed to be the maximum alike. With increasing the prestrain, both of the BH value and Snoek-Köster peak heights are similarly varied. It is concluded that Snoek-Köster and dislocation-enhanced Snoek peaks, caused by the interactions between interstitial solute carbon atoms and dislocations, can be used in further development of the bake hardening steels.

  3. Contributions of Rare Earth Element (La,Ce) Addition to the Impact Toughness of Low Carbon Cast Niobium Microalloyed Steels

    Science.gov (United States)

    Torkamani, Hadi; Raygan, Shahram; Garcia Mateo, Carlos; Rassizadehghani, Jafar; Palizdar, Yahya; San-Martin, David

    2018-03-01

    In this research Rare Earth elements (RE), La and Ce (200 ppm), were added to a low carbon cast microalloyed steel to disclose their influence on the microstructure and impact toughness. It is suggested that RE are able to change the interaction between the inclusions and matrix during the solidification process (comprising peritectic transformation), which could affect the microstructural features and consequently the impact property; compared to the base steel a clear evolution was observed in nature and morphology of the inclusions present in the RE-added steel i.e. (1) they changed from MnS-based to (RE,Al)(S,O) and RE(S)-based; (2) they obtained an aspect ratio closer to 1 with a lower area fraction as well as a smaller average size. Besides, the microstructural examination of the matrix phases showed that a bimodal type of ferrite grain size distribution exists in both base and RE-added steels, while the mean ferrite grain size was reduced from 12 to 7 μm and the bimodality was redressed in the RE-added steel. It was found that pearlite nodule size decreases from 9 to 6 μm in the RE-added steel; however, microalloying with RE caused only a slight decrease in pearlite volume fraction. After detailed fractography analyses, it was found that, compared to the based steel, the significant enhancement of the impact toughness in RE-added steel (from 63 to 100 J) can be mainly attributed to the differences observed in the nature of the inclusions, the ferrite grain size distribution, and the pearlite nodule size. The presence of carbides (cementite) at ferrite grain boundaries and probable change in distribution of Nb-nanoprecipitation (promoted by RE addition) can be considered as other reasons affecting the impact toughness of steels under investigation.

  4. AES and SIMS analysis of non-metallic inclusions in a low-carbon chromium-steel.

    Science.gov (United States)

    Gammer, Katharina; Rosner, M; Poeckl, G; Hutter, H

    2003-05-01

    In the final step of secondary metallurgical steel processing, calcium is added. Besides Mg, Ca is the most powerful deoxidiser and desulfurisation agent. It reacts with dissolved oxygen and sulfur and reduces oxides and sulfides thereby forming non-metallic inclusions. Within this paper we present the analysis of such inclusions in a low-carbon chromium-steel. Depending on the time of quenching of the steel sample, different structures were revealed by REM, Auger and SIMS: If the steel was quenched immediately after Ca-addition, non-metallic inclusions that appeared to have "cavities" could be detected with SEM. SIMS investigations of these particles showed ring-shaped structures and revealed that the ring is made up of Al, Ca, Mg, O and S. No secondary ions however could be retrieved from the core inside the ring, thus leaving the nature of the "cavities" unclear. If the steel sample was quenched 3 min after Ca addition, inclusions did not have a ring-shaped structure but a compact one.

  5. A Study on the Low Temperature Brittleness by Cyclic Cooling-Heating of Low Carbon Hot Rolled Steel Plate

    International Nuclear Information System (INIS)

    Lee, Hyo Bok

    1979-01-01

    The ductile-brittle transition phenomenon of low carbon steel has been investigated using the standard Charpy V-notch specimen. Dry ice and acetone were used as refrigerants. Notched specimens were cut from the hot rolled plate produced at POSCO for the Olsen impact test. The effect of cyclic cooling and heating of 0.14% carbon steel on the embrittlement was extensively examined. The ductile-brittle transition temperature was found to be approximately-30 .deg. C. The transition temperature was gradually increased as the number of cooling-heating cycles increased. On a typical V-notch fracture surface it was found that the ductile fracture surface showed a thick and fibrous structure, while the brittle fracture surface a small and light grain with irregular disposition. As expected, the transition temperature was also increased as the carbon content of steel increased. Compared with the case of 0.14% carbon steel, the transition temperature of 0.17% carbon steel was found to be increased about 12 .deg. C

  6. Low-carbon transition of iron and steel industry in China: carbon intensity, economic growth and policy intervention.

    Science.gov (United States)

    Yu, Bing; Li, Xiao; Qiao, Yuanbo; Shi, Lei

    2015-02-01

    As the biggest iron and steel producer in the world and one of the highest CO2 emission sectors, China's iron and steel industry is undergoing a low-carbon transition accompanied by remarkable technological progress and investment adjustment, in response to the macroeconomic climate and policy intervention. Many drivers of the CO2 emissions of the iron and steel industry have been explored, but the relationships between CO2 abatement, investment and technological expenditure, and their connections with the economic growth and governmental policies in China, have not been conjointly and empirically examined. We proposed a concise conceptual model and an econometric model to investigate this crucial question. The results of regression, Granger causality test and impulse response analysis indicated that technological expenditure can significantly reduce CO2 emissions, and that investment expansion showed a negative impact on CO2 emission reduction. It was also argued with empirical evidence that a good economic situation favored CO2 abatement in China's iron and steel industry, while achieving CO2 emission reduction in this industrial sector did not necessarily threaten economic growth. This shed light on the dispute over balancing emission cutting and economic growth. Regarding the policy aspects, the year 2000 was found to be an important turning point for policy evolution and the development of the iron and steel industry in China. The subsequent command and control policies had a significant, positive effect on CO2 abatement. Copyright © 2014. Published by Elsevier B.V.

  7. A study on low temperature transformation ferrite in ultra low carbon IF steels (I) - effects of manganese and annealing conditions

    International Nuclear Information System (INIS)

    Jeong, Woo Chang; Lee, Jae Yeon; Jin, Young Sool

    2001-01-01

    An investigation was made to determine the effects of Mn content and annealing conditions on the formation of the low temperature transformation products in ultra low carbon interstitial free steels. With increasing the Mn content, yield and tensile strengths increased, but yield ratio decreased. The Mn was found to be effective to decrease the yield point elongation, causing continuous yielding in 3% Mn steel. Low temperature transformation ferrites such as quasi-polygonal ferrite, granular bainitic ferrite, and bainitic ferrite more easily formed with higher Mn content, higher annealing temperature, longer annealing time, and faster cooling rate. Polygonal ferrite grain was readily identified in the light microscope and was characterized by the polyhedral and equiaxed shape while quasi-polygonal ferrite showed the irregular changeful grain boundaries. It was found that both granular bainitic and bainitic ferrites revealed some etching evidence of substructures in the light microscope

  8. Effect of Deformation Temperature on Microstructure Evolution and Mechanical Properties of Low-Carbon High-Mn Steel

    Directory of Open Access Journals (Sweden)

    Adam Grajcar

    2018-01-01

    Full Text Available This work addresses the influence of deformation temperature in a range from −40°C to 200°C on the microstructure evolution and mechanical properties of a low-carbon high-manganese austenitic steel. The temperature range was chosen to cope at the time during sheet processing or car crash events. Experimental results show that yield stress and ultimate tensile strength gradually deteriorate with an increase in the tensile testing temperature. The dominant mechanism responsible for the strain hardening of steel changes as a function of deformation temperature, which is related to stacking fault energy (SFE changes. When the deformation temperature rises, twinning decreases while a role of dislocation slip increases.

  9. Some observations on the carburization of type 316 stainless steel foil in a low carbon activity sodium environment

    International Nuclear Information System (INIS)

    Thorley, A.W.; Jeffcoat, P.J.

    1982-01-01

    Work currently being undertaken to establish the equilibrium composition of carbides which form in stainless steel foils during their exposure to low carbon activity sodium environment is described. The time it takes the carbon to reach equilibrium during exposure to sodium of different carbon activity is discussed. The lowest carbon activity measureable in test loops where the sodium is just above carburizing to stainless steel is reported. Analytical techniques are used to determine the composition of the carbide and the austenite matrix and hence estimate the carbon activity of the equilibrium structure. This provides a comparison with carbon activity values determined by alternative methods such as the Harwell Carbon Meter and nickel tab techniques

  10. Effects of heat treatment influencing factors on microstructure and mechanical properties of a low-carbon martensitic stainless bearing steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shaohong; Yuan, Xiaohong; Jiang, Wen; Sun, Hudai; Li, Jun [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Zhao, Kunyu, E-mail: zhaokunyu.kmust@gmail.com [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Yang, Maosheng [Department of Structural Materials, Central Iron and Steel Research Institute, Beijing 100081 (China)

    2014-05-01

    The effects of different heat treatment parameters and cryogenic treatment (−75 °C) on microstructural changes and mechanical properties of a low-carbon martensitic stainless bearing steel were investigated. These analyses were performed via the optical microscope (OM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The obtained results showed that the execution of cryogenic treatment on quenched and tempered bearing steel increases hardness, tensile strength and decreases toughness with the increment of cryogenic treatment and tempering cycles. This paper also showed that the cryogenic cycle's treatment incorporating tempering can refine the martensite laths resulting in improvement of tensile strength. In addition, cryogenic treatment further reduces the retained austenite content but it cannot make retained austenite transform into martensite completely even tempering at high temperature.

  11. Effects of heat treatment influencing factors on microstructure and mechanical properties of a low-carbon martensitic stainless bearing steel

    International Nuclear Information System (INIS)

    Li, Shaohong; Yuan, Xiaohong; Jiang, Wen; Sun, Hudai; Li, Jun; Zhao, Kunyu; Yang, Maosheng

    2014-01-01

    The effects of different heat treatment parameters and cryogenic treatment (−75 °C) on microstructural changes and mechanical properties of a low-carbon martensitic stainless bearing steel were investigated. These analyses were performed via the optical microscope (OM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The obtained results showed that the execution of cryogenic treatment on quenched and tempered bearing steel increases hardness, tensile strength and decreases toughness with the increment of cryogenic treatment and tempering cycles. This paper also showed that the cryogenic cycle's treatment incorporating tempering can refine the martensite laths resulting in improvement of tensile strength. In addition, cryogenic treatment further reduces the retained austenite content but it cannot make retained austenite transform into martensite completely even tempering at high temperature

  12. Further evaluation of creep-fatigue life prediction methods for low-carbon nitrogen-added 316 stainless steel

    International Nuclear Information System (INIS)

    Takahashi, Y.

    1999-01-01

    Low-carbon, medium-nitrogen 316 stainless steel is a principal candidate for a main structural material of a demonstration fast breeder reactor plant in Japan. A number of long-term creep tests and creep-fatigue tests have been conducted for four products of this steel. Two representative creep-fatigue life prediction methods, i.e., time fraction rule and ductility exhaustion method were applied. Total stress relaxation behavior was simulated well by an addition of a viscous strain term to the conventional (primary plus secondary) creep strain, but only the letter was assumed to contribute to creep damage in the ductility exhaustion method. The present ductility exhaustion approach was found to have very good accuracy in creep-fatigue life prediction for all materials tested, while the time fraction rule tended to overpredict failure life as large as a factor of 30. Discussion was made on the reason for this notable difference

  13. The CCT diagrams of ultra low carbon bainitic steels and their impact toughness properties

    International Nuclear Information System (INIS)

    Lis, A.K.; Lis, J.; Jeziorski, L.

    1998-01-01

    The CCT diagrams of ULCB N i steels, HN3MV, HN3MVCu having 5.1% Ni and 3.5% Ni and Cu bearing steels; HN3M1.5Cu, HSLA 100 have been determined. The reduced carbon concentration in steel, in order to prevent the formation of cementite, allowed for using nickel, manganese, chromium and molybdenum to enhance hardenability and refinement of the bainitic microstructures by lowering B S temperature. Copper and microadditions of vanadium and niobium are successfully used for precipitation strengthening of steel both in thermomechanically or heat treated conditions. Very good fracture toughness at low temperatures and high yield strength properties of HN3MVCu and HN3MV steels allowed for fulfillment of the requirements for steel plates for pressure vessels and cryogenic applications. (author)

  14. A novel blister test to evaluate the interface strength between nickel coating and low carbon steel substrate

    International Nuclear Information System (INIS)

    Xiao, L.H.; Su, Xu Ping.; Wang, J.H.; Zhou, Y.C.

    2009-01-01

    A novel blister test theory model was developed based on the bending theory of beams for assessing the interface strength of the nickel coating/low carbon steel substrate material system. The strain energy of the debonded nickel coating was calculated analytically and by finite element analysis, respectively. The analytic solutions agree well with the FE calculation results. Some blister tests were carried out on the WII-5 Computer Controlled Material Mechanical Properties Testing Machine, using four nickel-coated specimens type-A, -B, -C and -D which were electrodeposited on low carbon steel substrate. Here, types A, B, C and D correspond to the nickel coating thickness of 5 μm, 10 μm, 15μm and 25μm, respectively. The interface strength, evaluated by this blister test method, is 196.86 J/m 2 and 269.40 J/m 2 for type-C and -D specimens, respectively. However the tests demonstrate that the type-A and -B specimens were cut through by the spindle and no delaminations between the coating and the substrate could be found

  15. Corrosion Mechanism of Low-Carbon Steel in Industrial Water and Adsorption Thermodynamics in the Presence of Some Plant Extracts

    Science.gov (United States)

    Badiea, A. M.; Mohana, K. N.

    2009-12-01

    The effects of radish leaves and black cumin as plant extracts on the corrosion behavior of low-carbon steel in industrial water in the temperature range of 30 to 80 °C and velocity range of 1.44 to 2.02 m s-1 using potentiodynamic polarization, electrochemical impedance spectroscopy, and mass loss measurements have been investigated. The inhibition efficiency increased with increasing concentration of the plant extracts up to a critical value but it slightly decreased with increasing temperature. Inhibition efficiency values obtained from mass loss and potentiodynamic data were in reasonable agreement. Potentiodynamic polarization clearly indicated that radish leaves and black cumin extracts acted as anodic inhibitors. The adsorption behavior was found to obey the Flory-Huggins isotherm model. The associated activation parameters and thermodynamic data of adsorption were evaluated and discussed. The results show that radish leaves and black cumin could serve as effective inhibitors for low-carbon steel in industrial water media, with black cumin providing better protection than radish leaves.

  16. Morphology and Precipitation Kinetics of MnS in Low-Carbon Steel During Thin Slab Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    YU Hao; KANG Yong-lin; ZHAO Zheng-zhi; SUN Hao

    2006-01-01

    The morphology of manganese sulfide formed during thin slab continuous casting process in low-carbon steel produced by compact strip production (CSP) technique was investigated. Using transmission electron microscopy analysis, it was seen that a majority of manganese sulfides precipitated at austenite grain boundaries, the morphologies of which were spherical or close to the spherical shape and the size of MnS precipitates ranged from 30 nm to 100 nm. A mathematical model of the manganese sulfide precipitation in this process was developed based on classical nucleation theory. Under the given conditions, the starting and finishing precipitation temperatures of MnS in the continuous casting thin slab of the studied low-carbon steel are 1 189 ℃ and 1 171 ℃, respectively, and the average diameter of MnS precipitates is about 48 nm within this precipitation temperature range. The influences of chemical components and thermo-mechanical processing conditions on the precipitation behavior of MnS in the same process were also discussed.

  17. A study of electrochemically-induced corrosion of low carbon steel in a medium modelling acid rain

    International Nuclear Information System (INIS)

    Vertes, C.; Lakatos-Varsanyi, M.; Vertes, A.; Meisel, W.; Guetlich, P.

    1994-01-01

    Complementary electrochemical, spectrophotometric and electron microsopic investigations were made in addition to the conversion electron Moessbauer spectroscopic (CEMS) measurements to learn more about the mechanism of corrosion of low carbon steel samples in aqueous sulfate and sulfite containing sulfate solutions (pH 3.5, 6.5 and 8.5). Passivation of iron in pure sulfate solution was studied in detail in earlier papers. In the present work, we used a solution containing both sulfate and sulfite anions to obtain more information about the effect of acid rain on low carbon steel samples. The compositions and thicknesses of the passive films formed due to the electrochemical treatments were determined from the CEM spectra. γ-FeOOH was found in each case on the surface of the samples; nevertheless, at pH 3.5 the sextet belonging to Fe 3 C appears in the CEM spectra, and also FeSO 4 . H 2 O was detected in low concentration after the shortest polarization time (90 min). The results of the applied methods proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements referred to suppressed pitting at pH 8.5. (orig.)

  18. Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

    Directory of Open Access Journals (Sweden)

    Gui-qin FU

    2016-11-01

    Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*(α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

  19. Microstructure and partitioning behavior characteristics in low carbon steels treated by hot-rolling direct quenching and dynamical partitioning processes

    International Nuclear Information System (INIS)

    Li, Yun-jie; Li, Xiao-lei; Yuan, Guo; Kang, Jian; Chen, Dong; Wang, Guo-dong

    2016-01-01

    In this work, a new process and composition design are proposed for “quenching and partitioning” or Q&P treatment. Three low carbon steels were treated by hot-rolling direct quenching and dynamical partitioning processes (DQ&P). The effects of proeutectoid ferrite and carbon concentration on microstructure evolution and mechanical properties were investigated. The present work obtained DQ&P prototype steels with good mechanical properties and established a new notion on compositions for Q&P processing. Microstructures were characterized by means of electro probe microanalyzer (EPMA), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD), especially the morphology and size of retained austenite. Mechanical properties were measured by uniaxial tensile tests. The results indicated that introducing proeutectoid ferrite can increase the volume fraction of retained austenite and thus improve mechanical properties. TEM observation showed that retained austenite included the film-like inter-lath austenite and blocky austenite located in martensite/ferrite interfaces or surrounded by ferrites. It was interesting that when the carbon concentration is as low as ~ 0.078%, the film-like inter-lath untransformed austenite cannot be stabilized to room temperature and almost all of them transformed into twin martensite. The blocky retained austenite strengthened the interfaces and transformed into twin martensite during the tensile deformation process. The PSEs of specimens all exceeded 20 GPa.%. - Highlights: •This study focused on a new process: Q&P process applying dynamical partitioning. •Ferrite can increase the volume fraction of retained austenite. •The film-like austenite and the blocky austenite were observed. •The low carbon steels treated by new process reached PSEs higher than 20 GPa.%.

  20. A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang, E-mail: wy069024019@163.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Zhang, Yuan-Xiang; Lu, Xiang; Fang, Feng; Xu, Yun-Bo; Cao, Guang-Ming; Li, Cheng-Gang [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, TX 79968 (United States); Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2016-12-01

    A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two-stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110}<001>) and λ-fiber (<001>//ND). The coarse sulfides of size ~100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AlN particles of size ~20–50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AlN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary recrystallization annealing, very large grains of size ~10–40 mm were formed and the final magnetic induction, B{sub 8}, was as high as 1.9 T. - Highlights: • A novel chemical composition base on strip casting silicon steel was proposed. • The ultra-low carbon design could shorten the processing routes. • The novel composition and processes were beneficial to obtain more inhibitors. • The magnetic induction of grain oriented silicon steel was significantly improved.

  1. Processing of low carbon steel plate and hot strip—an overview

    Indian Academy of Sciences (India)

    Unknown

    hybrid computer modelling is used for production of strip products with tailor made properties. Although there ..... Thanks are due to the management of SAIL for support and to ... Houdremont E 1956 Handbook of special steels (Berlin: Springer ...

  2. Microstructure and grain size effects on irradiation hardening of low carbon steel for reactor tanks

    Energy Technology Data Exchange (ETDEWEB)

    Milasin, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1964-05-15

    Irradiation hardening of steel for reactor pressure vessels has been studied extensively during the past few years. A great number of experimental results concerning the behaviour of these steels in the radiation field and several review papers (1,2) have been published. Most of the papers deal with the effects of specific metallurgical factors or irradiation conditions (temperature, flux) on irradiation hardening and embrittlement. In addition, a number of experiments are performed to give evidence on the mechanism of irradiation hardening of these steels. However, this mechanism is still unknown due to the complexity of steel as a system. Among different methods used in radiation damage studies, the changes of mechanical properties have been mainly investigated. By using Hall-Petch's empirical relation, {sigma}{sub y}={sigma}{sub i}+k{sub y} d{sup -1/2} between lower yield stress, {sigma}{sub y}, and grain size, 2d, the information about the effect of irradiation on the parameters {sigma}{sub i} and k{sub y} is obtained. Taking as a base interpretation of {sigma}{sub i} and k{sub y} given by Petch and his co-workers it has been concluded that radiation does not change the stress to start slip but that it increase the friction that opposes the passage of free dislocations across a slip plane. In attempting to apply Hall-Petch's relation to one unirradiated ferritic steel with a carbon content higher than 0.15% some difficulties were encountered. The results obtained indicate that the influence of grain size can not be isolated from other factors introduced by the treatments used to produce different grain sizes. This paper deals with a similar problem in the case of irradiated steel. The results obtained give the changes of the mechanical properties of steel in neutron irradiation field as a function of microstructure and grain size. In addition, the mechanical properties of irradiated steel are measured after annealing at 150 deg C and 450 deg C. On the basis of

  3. Microstructure and grain size effects on irradiation hardening of low carbon steel for reactor tanks

    International Nuclear Information System (INIS)

    Milasin, N.

    1964-05-01

    Irradiation hardening of steel for reactor pressure vessels has been studied extensively during the past few years. A great number of experimental results concerning the behaviour of these steels in the radiation field and several review papers (1,2) have been published. Most of the papers deal with the effects of specific metallurgical factors or irradiation conditions (temperature, flux) on irradiation hardening and embrittlement. In addition, a number of experiments are performed to give evidence on the mechanism of irradiation hardening of these steels. However, this mechanism is still unknown due to the complexity of steel as a system. Among different methods used in radiation damage studies, the changes of mechanical properties have been mainly investigated. By using Hall-Petch's empirical relation, σ y =σ i +k y d -1/2 between lower yield stress, σ y , and grain size, 2d, the information about the effect of irradiation on the parameters σ i and k y is obtained. Taking as a base interpretation of σ i and k y given by Petch and his co-workers it has been concluded that radiation does not change the stress to start slip but that it increase the friction that opposes the passage of free dislocations across a slip plane. In attempting to apply Hall-Petch's relation to one unirradiated ferritic steel with a carbon content higher than 0.15% some difficulties were encountered. The results obtained indicate that the influence of grain size can not be isolated from other factors introduced by the treatments used to produce different grain sizes. This paper deals with a similar problem in the case of irradiated steel. The results obtained give the changes of the mechanical properties of steel in neutron irradiation field as a function of microstructure and grain size. In addition, the mechanical properties of irradiated steel are measured after annealing at 150 deg C and 450 deg C. On the basis of the experimental results obtained the relative microstructure and

  4. The effects of deoxidation practice on the quality of thin foil low-carbon steel

    Directory of Open Access Journals (Sweden)

    Pereira Batista R.

    2017-01-01

    Full Text Available In converter steelmaking of AISI 1006 steel for thin foil products, two tapping practices are used with respect to deoxidation: silicon and manganese additions during tapping and aluminum deoxidation after complete tapping (“semikilled practice” and aluminum deoxidation during tapping, “fully killed practice”. There is a perception that the semikilled practice may be more economical and result in the same quality as the fully killed practice. In this work, the effects of the tapping practice on steel quality and cost variables were evaluated for thin foils of AISI 1006 steel. Oxygen and aluminum content, aluminum and ferro-alloy yield, the type of alumina inclusions formed, and the quality of the steel during thin foil rolling were evaluated and compared. It is shown that the fully killed practice leads to less reoxidation from slag, lower soluble oxygen, and lower total oxygen at the caster as well as better morphology of the remaining alumina inclusions than the semi-killed practice. Thus, the higher quality of the steel produced via the fully killed tapping deoxidation practice when compared with semi-killed tapping is demonstrated. It is also shown that a complete cost evaluation favors this practice in the case of products rolled for tin foil production.

  5. Corrosion Resistance and Pitting Behaviour of Low-Carbon High-Mn Steels in Chloride Solution

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available Corrosion resistance of the X4MnSiAlNbTi27-4-2 and X6MnSiAlNbTi26-3-3 type austenitic steels, after hot deformation as well as after cold rolling, were evaluated in 3.5% NaCl solution using potentiodynamic polarization tests. A type of nonmetallic inclusions and their pitting corrosion behaviour were investigated. Additionally, the effect of cold deformation on the corrosion resistance of high-Mn steels was studied. The SEM micrographs revealed that corrosion damage formed in both investigated steels is characterized by various shapes and an irregular distribution at the metallic matrix, independently on the steel state (thermomechanically treated or cold worked. Corrosion pits are generated both in grain interiors, grain boundaries and along the deformation bands. Moreover, corrosion damage is stronger in cold deformed steels in comparison to the thermomechanically treated specimens. EDS analysis revealed that corrosion pits preferentially nucleated on MnS and AlN inclusions or complex oxysulphides. The morphology of corrosion damage in 3.5% NaCl supports the data registered in potentiodynamic tests.

  6. Application of Moessbauer effect in the study of austenite retained in low carbon steel

    International Nuclear Information System (INIS)

    Azevedo, A.L.T. de; Silva, E.G. da

    1979-01-01

    Moessbauer effect measurements of two samples of low carbon alloy having micro-structure of granular bainite type and martensite type have been done. The concentration of the retained austenite in both samples was determined by Moessbauer effect and x-rays there, being agreement for the higher austenite content sample. Concentration of carbon in the MA (Martensite - Austenite) constituents of bainite is also ditermined, the results being in agreement with metallographic considerations. Carbon enrichments are shown as responsible by the stabilization of the austenite in the granular bainite. Spectra of both samples present three magnetic configurations for α-iron with medium magnetic fields iqual to 335, 307 and 280 KOe. (A.R.H.) [pt

  7. Effect of microstructure on the cleavage fracture strength of low carbon Mn-Ni-Mo bainitic steels

    International Nuclear Information System (INIS)

    Im, Young-Roc; Lee, Byeong-Joo; Oh, Yong Jun; Hong, Jun Hwa; Lee, Hu-Chul

    2004-01-01

    The effects of the microstructure on the cleavage fracture strength of low carbon Mn-Ni-Mo bainitic steels were examined. A four-point bend test and double-notched bend specimens were used to measure the cleavage fracture strength of the alloys and identify the cleavage initiating micro-cracks, respectively. The cleavage fracture strength and DBTT of Mn-Ni-Mo bainitic steels were strongly affected by the alloy carbon content. The decrease in the alloy carbon content resulted in a decrease in the inter-lath cementite-crowded layers and higher cleavage fracture strength. Micro-cracks that formed across the inter-lath cementite-crowded layers were observed to initiate cleavage fracture. The width of these inter-lath cementite-crowded layers was accepted as a cleavage initiating micro-crack size in the micro-mechanical modeling of the cleavage fracture, and the measured cleavage strength values of the bainitic Mn-Ni-Mo steels were well represented by the modified Griffith relationship

  8. Cleanliness of Ti-bearing Al-killed ultra-low-carbon steel during different heating processes

    Science.gov (United States)

    Guo, Jian-long; Bao, Yan-ping; Wang, Min

    2017-12-01

    During the production of Ti-bearing Al-killed ultra-low-carbon (ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl-Heraeus (RH) process was low: heating by Al addition during the RH decarburization process and final deoxidation at the end of the RH decarburization process (process-I), and increasing the oxygen content at the end of RH decarburization, heating and final deoxidation by one-time Al addition (process-II). Temperature increases of 10°C by different processes were studied; the results showed that the two heating processes could achieve the same heating effect. The T.[O] content in the slab and the refining process was better controlled by process-I than by process-II. Statistical analysis of inclusions showed that the numbers of inclusions in the slab obtained by process-I were substantially less than those in the slab obtained by process-II. For process-I, the Al2O3 inclusions produced by Al added to induce heating were substantially removed at the end of decarburization. The amounts of inclusions were substantially greater for process-II than for process-I at different refining stages because of the higher dissolved oxygen concentration in process-II. Industrial test results showed that process-I was more beneficial for improving the cleanliness of molten steel.

  9. Design of duplex low carbon steels for improved strength: weight applications

    Energy Technology Data Exchange (ETDEWEB)

    Koo, J.

    1977-08-01

    Duplex ferrite-martensite (DFM) steels with excellent combinations of strength and formability have been selected from first principles, and their microstructure-property relationships established through a systematic investigation of a series of ternary Fe/X/0.1 C steels (X being varying amount of Cr and Si). Duplex processing consists of initial austenitization and quenching to form 100% martensite, followed by annealing in the (..cap alpha.. + ..gamma..) range and subsequent quenching. The resultant DFM morphology is controlled by the type and amount of alloying element X.

  10. High toughness in the intercritically reheated coarse-grained (ICRCG) heat-affected zone (HAZ) of low carbon microalloyed steel

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jun, E-mail: hujunral@163.com [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Du, Lin-Xiu [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Wang, Jian-Jun [Institute of Materials Research, School of Material and Metallurgy, Northeastern University, Shenyang 110819 (China); Xie, Hui; Gao, Cai-Ru [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States)

    2014-01-10

    Motivated by the small lattice mismatch between ferrite and vanadium nitride (VN), we describe here the welding thermal cycle simulation that provides high toughness in the ICRCG HAZ of low carbon V–N steel. This unique behavior is attributed to the formation of ultra-fine grained ferrite along prior austenite grain boundaries generated by the first pass welding thermal cycle with high misorientation boundaries, where V(C, N) precipitates provide potential nucleation sites for ferrite, leading to extraordinary refinement of martensite/austenite (M/A) constituent. Nitrogen stimulates the precipitation behavior of V(C, N). The nucleation of high density of V(C, N) precipitates consumes carbon-content in the austenite, leading to decrease in the carbon-content in the M/A constituent, with consequent decrease in hardness. The increase in toughness is explained in terms of Griffith's crack propagation theory.

  11. Microstructural research on hot strips of low carbon steel produced by a compact strip production line under different thermal histories

    International Nuclear Information System (INIS)

    Yu Hao; Chen Qixiang; Kang Yonglin; Sun Yi

    2005-01-01

    Coupons with the same composition and thickness (4.0 mm nominal gauge) obtained from hot strips of low carbon steel underwent a series of investigations to analyze the microstructural characteristics and mechanisms responsible for their differences in mechanical properties. Two different industrial technologies were adopted, although the strips used in this research were produced on the same Compact Strip Production (CSP) line. One of the strips was produced with a routine γ→α CSP thermal history, but the other with a γ→α→γ* conventional thermal history. The only difference between them was that one technology had a α→γ* thermal history. Different specimens of both types of strips were prepared for metallographic observation, tensile tests, electron back-scattered diffraction tests and positron annihilation technique tests. Experimental results showed that the differences in mechanical properties could be ascribed to dissimilarities not only in the grain size and textural components but also in dislocation density

  12. Influence of shielding gas composition on weld profile in pulsed Nd:YAG laser welding of low carbon steel

    Directory of Open Access Journals (Sweden)

    M Jokar

    2014-12-01

    Full Text Available Weld area and weld depth/width ratio can be considered to be of the most important geometrical factors in pulsed laser welding. The effects of carbon dioxide and oxygen additions to the argon shielding gas on the weld properties in pulsed laser welding of low carbon steel is investigated. Presence of carbon dioxide and oxygen up to 10 and 15 percent respectively decreases the weld geometrical factors. But, at higher levels of additions, the weld geometrical factors will increase. It is observed that the plasma plume temperature decreases from 6000K to 5500K with the addition of 15% carbon dioxide but increases to 7700K with 25% carbon dioxide addition. Increase in laser absorption coefficient, laser energy absorption, formation of oxide layer on the work-piece surface, exothermic reactions and their competitive effects can be considered as the competing phenomena involved in such a behavior in the weld profile

  13. High toughness in the intercritically reheated coarse-grained (ICRCG) heat-affected zone (HAZ) of low carbon microalloyed steel

    International Nuclear Information System (INIS)

    Hu, Jun; Du, Lin-Xiu; Wang, Jian-Jun; Xie, Hui; Gao, Cai-Ru; Misra, R.D.K.

    2014-01-01

    Motivated by the small lattice mismatch between ferrite and vanadium nitride (VN), we describe here the welding thermal cycle simulation that provides high toughness in the ICRCG HAZ of low carbon V–N steel. This unique behavior is attributed to the formation of ultra-fine grained ferrite along prior austenite grain boundaries generated by the first pass welding thermal cycle with high misorientation boundaries, where V(C, N) precipitates provide potential nucleation sites for ferrite, leading to extraordinary refinement of martensite/austenite (M/A) constituent. Nitrogen stimulates the precipitation behavior of V(C, N). The nucleation of high density of V(C, N) precipitates consumes carbon-content in the austenite, leading to decrease in the carbon-content in the M/A constituent, with consequent decrease in hardness. The increase in toughness is explained in terms of Griffith's crack propagation theory

  14. The aging by precipitation of Nb (C,N) in extra low carbon content steel

    International Nuclear Information System (INIS)

    Bruno, J.C.; Kestenbach, H.-J.

    1982-01-01

    Carbonitride precipitation has been studied in a high-niobium acicular - ferrite - type steel. Interphase precipitation occurred only in those samples in which high transformation temperatures led to distinctly polygonal-ferrite microestructures. In this latter case, precipitation occurred during a subsequent aging treatment, with a strong tendency for heterogeneous nucleation on dislocations. (Author) [pt

  15. Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides

    Science.gov (United States)

    Corrosion is one of the most serious and challenging problems faced worldwide by industry. This research investigates the inhibition of corrosive behavior of SAE1010 steel by bacterial exopolysaccharides. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion inhibition of diffe...

  16. Explosive Forming of Low Carbon Steel Sheet into a Stepped Disc Shape

    OpenAIRE

    S. Balasubramanian; S. Sarvat Ali; E.S. Bhagiradha Rao

    1984-01-01

    This paper deals with the explosive forming of deep drawing quality steel into a two stepped disc type shape. An attempt has been made to predict the forming parameters from theoretical considerations by equating the disc shape with an equivalent dome. Results of forming this shape in a single stage vis-a-vis forming in two stages are compared.

  17. Phase transformations in low-carbon manganese steel 6Mn16

    Directory of Open Access Journals (Sweden)

    J. Lis

    2009-01-01

    Full Text Available The kinetics of phase transformations of the austenite of 6Mn16 steel during continuous cooling are presented in a CCT diagram. Manganese partitioning between ferrite and austenite during intercritical annealing is enhanced by prior soft annealing. Due to the increased Mn concentration in austenite, the temperatures BS and MS have decreased, as compared to those achieved during cooling from the complete austenite region.

  18. The influence of Cr and Al pack cementation on low carbon steel to improve oxidation resistance

    Science.gov (United States)

    Prasetya, Didik; Sugiarti, Eni; Destyorini, Fredina; Thosin, Kemas Ahmad Zaini

    2012-06-01

    Pack chromizing and aluminizing has been widely used for many years to improve hot temperature oxidation and corrosion resistance of metals. The coating process involves packing the steel in a powder mixture which contain aluminum and chromium source, and inert filler (usually alumina), and halide activator NH4Cl. Al and Cr were deposited onto carbon steel by pack cementation process using elemental Al and Cr powder as Al and Cr source, whereas NiCo alloys codeposited by electrodeposition. The position of Al and Cr could be under or over Ni-Co alloys deposited. Pack cementation was heated on dry inert gas at temperature 800 °C about 5 hours and 20 minute for Cr and Al respectively. Al and Cr was successfully deposited. Laying down effect of Al and Cr onto carbon steel whether up and down toward NiCo alloys coating have affected to oxidation resistance. The pack aluminizing as top layer given best resitance to restrain excessive oxide scale, in contrast pack chromizing reveal bad oxidation resistance, moreover occured spallation on layer.

  19. Passivation of Cu-Zn alloy on low carbon steel electrodeposited from a pyrophosphate medium

    Science.gov (United States)

    Yavuz, Abdulcabbar; Yakup Hacıibrahimoğlu, M.; Bedir, Metin

    2018-01-01

    The motivation of this study is to understand whether zinc-based alloy also has a passivation behaviour similar to zinc itself. Cu-Zn alloys were electrodeposited potentiostatically from a pyrophosphate medium on a carbon steel electrode and their corrosion behaviours were studied. Pt and carbon steel electrodes were used in order to examine the corrosion/passivation behaviour of bare Cu, bare Zn and Cu-Zn alloy coatings. The passivation behaviour of all brass-modified electrodes having Zn content between 10% and 100% was investigated. The growth potential affects the morphology and structure of crystals. The brass coatings are more porous than their pure components. The crystalline structure of Cu-Zn alloys can be obtained by changing the deposition potential. The zinc content in brass increases when the deposition voltage applied decreases. However, the growth potential and the ratio of zinc in brass do not affect the passivation behaviour of the resulting alloys. The coatings obtained by applying different growth potentials were immersed in tap water for 24 h to compare their corrosion behaviours with carbon steel having pitting formation.

  20. Phase-field modelling of microstructure formation during the solidification of continuously cast low carbon and HSLA steels

    Science.gov (United States)

    Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

    2012-07-01

    Cracking in continuous casting of steels has been one of the main problems for decades. Many of the cracks that occur during solidification are hot tears. To better understand the factors leading to this defect, microstructure formation is simulated for a low carbon (LCAK) and two high strength low alloyed (HSLA) steel grades during the initial stage of the process where the first solidified shell is formed inside the mould and where breakouts typically occur. 2D simulation is performed using the multiphase-field software MICRESS [1], which is coupled to the thermodynamic database TCFE6 [2] and the mobility database MOB2 [2], taking into account all elements which may have a relevant effect on the mechanical properties and structure formation during or subsequent to solidification. The use of a moving-frame boundary condition allows travelling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. A heterogeneous nucleation model is included to permit the description of morphological transitions between the initial solidification and the subsequent columnar growth region. Furthermore, a macroscopic one-dimensional temperature solver is integrated to account for the transient and nonlinear temperature field during the initial stage of continuous casting. The external heat flux boundary conditions for this process were derived from thermal process data of the industrial slab caster. The simulation results for the three steel grades have been validated by thickness measurements of breakout shells and microstructure observation of the corresponding grades. Furthermore, the primary dendrite spacing has been measured across the whole thickness of the shell and compared with the simulated microstructures. Significant microstructure differences between the steel grades are discussed and correlated with their hot-cracking behavior.

  1. Phase-field modelling of microstructure formation during the solidification of continuously cast low carbon and HSLA steels

    International Nuclear Information System (INIS)

    Böttger, B; Apel, M; Santillana, B; Eskin, D G

    2012-01-01

    Cracking in continuous casting of steels has been one of the main problems for decades. Many of the cracks that occur during solidification are hot tears. To better understand the factors leading to this defect, microstructure formation is simulated for a low carbon (LCAK) and two high strength low alloyed (HSLA) steel grades during the initial stage of the process where the first solidified shell is formed inside the mould and where breakouts typically occur. 2D simulation is performed using the multiphase-field software MICRESS, which is coupled to the thermodynamic database TCFE6 and the mobility database MOB2, taking into account all elements which may have a relevant effect on the mechanical properties and structure formation during or subsequent to solidification. The use of a moving-frame boundary condition allows travelling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. A heterogeneous nucleation model is included to permit the description of morphological transitions between the initial solidification and the subsequent columnar growth region. Furthermore, a macroscopic one-dimensional temperature solver is integrated to account for the transient and nonlinear temperature field during the initial stage of continuous casting. The external heat flux boundary conditions for this process were derived from thermal process data of the industrial slab caster. The simulation results for the three steel grades have been validated by thickness measurements of breakout shells and microstructure observation of the corresponding grades. Furthermore, the primary dendrite spacing has been measured across the whole thickness of the shell and compared with the simulated microstructures. Significant microstructure differences between the steel grades are discussed and correlated with their hot-cracking behavior.

  2. Effect of heat treatment and cleanness of ultra low carbon bainitic (ULCB) steel on its impact toughness

    International Nuclear Information System (INIS)

    Lis, A.K.

    1998-01-01

    The small variations in sulphur and carbon concentrations can have a major influence on the impact transition temperature (ITT) of ultra low carbon HSLA-100 steel which has been quenched in water and tempered (WQ and T). Since the average carbon concentration is very low thus sensitivity of ITT to heat treatment parameters depends also on the yield strength increase due to precipitation effect of ε C u phase. The regression analysis has been used to establish equations taking into account those parameters. The properties of a mixed microstructure formed from partially austenitic regions have been also considered. The fine austenitic grains transform into more desirable fine bainitic ferrite phases with lower hardness values and higher toughness. On the other hand, if cooling rate is sufficiently large, then the carbon enriched austenite transforms partially into hard martensite and some of remaining untransformed austenite being retained to ambient temperature. Because hard martensite islands are located in much softer surroundings consisting of tempered ferrite, they do not cause a general reduction in impact toughness tests. Due to further grain refinement of microstructure the measured toughness on Charpy V specimens can be very high at low temperatures. The very detrimental effect of sulphur in ULCB steel has been confirmed by presented results. (author)

  3. Microstructural evolution and mechanical properties of low-carbon steel treated by a two-step quenching and partitioning process

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shu [The State Key Laboratory of Rolling & Automation, Northeastern University, Shenyang 110819 (China); Liu, Xianghua, E-mail: liuxh@mail.neu.edu.cn [The State Key Laboratory of Rolling & Automation, Northeastern University, Shenyang 110819 (China); Research Academy, Northeastern University, Shenyang 110819 (China); Liu, Wayne J [Research Academy, Northeastern University, Shenyang 110819 (China); Lan, Huifang; Wu, Hongyan [The State Key Laboratory of Rolling & Automation, Northeastern University, Shenyang 110819 (China)

    2015-07-29

    The quenching and partitioning (Q&P) process is studied in Ti-bearing low-carbon steel. Detailed characterization of the microstructural evolution is performed by means of optical microscopy, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results indicate that the investigated steel subjected to the Q&P process forms a multiphase microstructure of primarily lath martensite, with small amounts of plate-type martensite and retained austenite. The distribution and morphology of the retained austenite are observed; moreover the relationship between the phase fraction of the retained austenite, its carbon concentration, and the partitioning conditions is established. Carbides preferentially precipitate within the plate-type martensite at first, and gradually form in the martensitic laths over time during the partitioning step. Additionally, titanium precipitations contribute to both the refinement of prior austenite grains and the improvement of strength by precipitation strengthening. The results of mechanical properties testing indicate that the samples partitioned at 400 °C exhibit a superior combination of strength and elongation, with products of the two properties ranging between 19.6 and 20.9 GPa%. Based on analysis of work hardening behavior it is determined that the higher ductility is closely related to the higher phase fraction and/or stability of retained austenite.

  4. Quantitative analysis of inclusions in low carbon free cutting steel using small-angle X-ray and neutron scattering

    International Nuclear Information System (INIS)

    Oba, Yojiro; Koppoju, Suresh; Ohnuma, Masato; Kinjo, Yuki; Tomota, Yo; Morooka, Satoshi; Suzuki, Jun-ichi; Yamaguchi, Daisuke; Koizumi, Satoshi; Sato, Masugu; Shiraga, Tetsuo

    2012-01-01

    The microstructure of inclusions in low carbon free cutting steel without lead addition was investigated using small-angle X-ray scattering (SAXS) coupled with small-angle neutron scattering (SANS). The two-dimensional (2D) SAXS pattern shows clear scattering due to inclusions composed of large elongated particles aligned along the rolling direction, and small isotropic particles. From a comparison of the simulated and experimental 2D SAXS patterns, the shapes of the inclusions are regarded as ellipsoid for the larger inclusions and spherical for the smaller inclusions. The length of the minor axis in the large inclusion is 6.9 μm, while the diameter of the small inclusion is 0.50 μm. The aspect ratio of the large inclusion is estimated to be 3.8 in the lower q region, and is reduced slightly to 3.5 in the higher q region from the azimuthal plots. The results of an alloy contrast variation (ACV) analysis using both the SAXS and SANS data indicate that the chemical composition of the inclusions is almost NaCl-type manganese sulfide, and that the amount of iron sulfide is low. The volume fractions are 1.4% for the large inclusions and 0.2% for the small inclusions. This is consistent with the area fraction estimated using an optical microscope, and indicates that nearly all of the sulfur in the steel sample forms the manganese sulfide inclusions. (author)

  5. Microstructural development during the quenching and partitioning process in a newly designed low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Santofimia, M.J., E-mail: m.j.santofimianavarro@tudelft.nl [Materials Innovation Institute (M2i), Mekelweg 2, 2628 CD Delft (Netherlands); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Zhao, L. [Materials Innovation Institute (M2i), Mekelweg 2, 2628 CD Delft (Netherlands); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Petrov, R. [Department of Metallurgy and Materials Science, Ghent University, Technologiepark 903, 9052 Ghent (Belgium); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Kwakernaak, C.; Sloof, W.G.; Sietsma, J. [Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands)

    2011-09-15

    This paper presents a detailed characterization of the microstructural development of a new quenching and partitioning (Q and P) steel. Q and P treatments, starting from full austenitization, were applied to the developed steel, leading to microstructures containing volume fractions of retained austenite of up to 0.15. The austenite was distributed as films in between the martensite laths. Analysis demonstrates that, in this material, stabilization of austenite can be achieved at significantly shorter time scales via the Q and P route than is possible via a bainitic isothermal holding. The results showed that the thermal stabilization of austenite during the partitioning step is not necessarily accompanied by a significant expansion of the material. This implies that the process of carbon partitioning from martensite to austenite occurs across low-mobility martensite-austenite interfaces. The amount of martensite formed during the first quench has been quantified. Unlike martensite formed in the final quench, this martensite was found to be tempered during partitioning. Measured volume fractions of retained austenite after different treatments were compared with simulations using model descriptions for carbon partitioning from martensite to austenite. Simulation results confirmed that the carbon partitioning takes place at low-mobility martensite-austenite interfaces.

  6. DEVELOPMENT OF FLUORINE-FREE MOULD FLUX APPLIED IN LOW CARBON STEEL

    Directory of Open Access Journals (Sweden)

    Jayme Alves de Souza Junior

    2012-12-01

    Full Text Available ract The mould flux is a mixture of non-metallic oxides that, in contact with liquid steel melts, becomes a liquid slag which the mainly function is to lubricate and control heat transfer between mould and strand during the continuous casting process. The mould flux without fluoride has the advantage of decreasing the wear of machine and the SEN in comparison to common mould flux. The application in Continuous Casting of Slabs has been a great challenge in relation to the operational viability together with internal and surface quality of slabs. Another differential is the decrease of environmental issues on account of the contamination of secondary cooling water by the fluorides. It is considered that properties of mould flux as chemical composition, viscosity, softening, melting flowing temperatures, fusion rate, etc, should be suitable to the chemical composition and the mechanical properties at elevated temperatures of steel and also the operational parameters such as casting temperature, casting speed, mould frequency, among others. This work presents a preliminary analysis in relation to operational viability, analysis of surface quality of slabs, measurements of fluorides content in the water of secondary cooling of machine. In addition to that, the analyses of operational features as measurements of wear of SEN, mould flux consumption, slag pool and behavior of thermocouples of detection system break outs (MSD are considered.

  7. Corrosion of low carbon steel by microorganisms from the 'pigging' operation debris in water injection pipelines.

    Science.gov (United States)

    Cote, Claudia; Rosas, Omar; Sztyler, Magdalena; Doma, Jemimah; Beech, Iwona; Basseguy, Régine

    2014-06-01

    Present in all environments, microorganisms develop biofilms adjacent to the metallic structures creating corrosion conditions which may cause production failures that are of great economic impact to the industry. The most common practice in the oil and gas industry to annihilate these biofilms is the mechanical cleaning known as "pigging". In the present work, microorganisms from the "pigging" operation debris are tested biologically and electrochemically to analyse their effect on the corrosion of carbon steel. Results in the presence of bacteria display the formation of black corrosion products allegedly FeS and a sudden increase (more than 400mV) of the corrosion potential of electrode immersed in artificial seawater or in field water (produced water mixed with aquifer seawater). Impedance tests provided information about the mechanisms of the interface carbon steel/bacteria depending on the medium used: mass transfer limitation in artificial seawater was observed whereas that in field water was only charge transfer phenomenon. Denaturing Gradient Gel Electrophoresis (DGGE) results proved that bacterial diversity decreased when cultivating the debris in the media used and suggested that the bacteria involved in the whole set of results are mainly sulphate reducing bacteria (SRB) and some other bacteria that make part of the taxonomic order Clostridiales. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Effect of carbon content on microstructure and mechanical properties of hot-rolled low carbon 12Cr-Ni stainless steel

    International Nuclear Information System (INIS)

    Zheng, H.; Ye, X.N.; Li, J.D.; Jiang, L.Z.; Liu, Z.Y.; Wang, G.D.; Wang, B.S.

    2010-01-01

    Research highlights: → Hot-rolled ultra low carbon martensite is characterized by dislocation cells substructure. → The formation of dislocation cells is attributed to high Ms and low interstitial atoms content. → Hot-rolled ultra low carbon 12Cr-Ni stainless steel has excellent impact toughness. → Delta ferrite deteriorates the impact toughness of hot-rolled 12Cr-Ni stainless steel. - Abstract: 12Cr-Ni stainless steels containing different carbon contents from 0.004 wt.% to 0.034 wt.% were hot-rolled and air-cooled. Their corresponding microstructures were observed with optical microscope and transmission electron microscope, and the Vickers hardness, tensile and impact tests were also carried out. It was found that the martensitic morphology was significantly influenced by carbon content. The as-received ultra low carbon martensite in the steel containing 0.004 wt.% C is characterized by dislocation cells substructure. The formation of dislocation cells is attributed to high martensite finishing point (above 400 deg. C) and low interstitial atoms content. On the other hand, the martensite in the steel containing 0.034 wt.% C consists mainly of typical martensite laths because of low martensite finishing point and high interstitial atoms content which hinder dislocation motion. Furthermore, carbon content has an evident effect on the mechanical properties of 12Cr-Ni steels. The hardness and strength of the as-received steels increase with an increase in carbon content, but their elongation and impact toughness decrease with the carbon content. The steel containing 0.004 wt.% C has excellent impact toughness due to the ultra low carbon content in the martensite composed of dislocation cells.

  9. Polarized BRDF measurement of the type E235B low carbon structural steel

    Science.gov (United States)

    Liu, Yanlei; Yu, Kun; Zhang, Kaihua; Liu, Yufang

    2018-01-01

    Bidirectional reflectance distribution function (BRDF) offers complete description of the spectral and spatial characteristics of opaque materials. The polarized BRDF contains more information, especially for the painted objects and target recognition. In this letter, we measured the in plane polarized spectral BRDF for the steel E235B in the wavelength range of 450-600 nm. The reliability of our results is verified by comparing the experimental data of polytetrafluoroethylene with the reference data. The measuring results indicates that the wavelength of incident light has a positive effect on the BRDF near the specular direction, and has a negative influence for other direction. BRDF increases slowly with reflected zenith angle and decreases rapidly with peak occurs at specular direction, which may be attributed to the shadowing effect. In addition, the results presents that the polarization of incident light has a slight influence on the BRDF of the sample.

  10. Anti-carburizing Coating for Resin Sand Casting of Low Carbon Steel Based on Composite Silicate Powder Containing Zirconium

    Directory of Open Access Journals (Sweden)

    Zhan Chunyi

    2018-01-01

    Full Text Available This paper studied the structure and properties of anticarburizing coating based on composite silicate powder containing zirconium by X-ray diffraction analyzer, thermal expansion tester, digital microscope and other equipment. It is introduced that the application example of the coating in the resin-sand casting of ZG1Cr18Ni9Ti stainless steel impeller. The anti-carburizing effect of the coating on the surface layer of the cast is studied by using direct reading spectrometer and spectrum analyzer. The change of the micro-structure of the coating after casting and cooling is observed by scanning electron microscope. The analysis of anti-carburizing mechanism of the coating is presented. The results indicate that the coating possesses excellent suspension property, brush ability, permeability, levelling property and crackresistance. The coating exhibits high strength and low gas evolution. Most of the coating could be automatically stripped off flakily when the casting was shaken out. The casting possesses excellent surface finish and antimetal penetration effect. The carburizing layer thickness of the stainless steel impeller casting with respect to allowable upper limit of carbon content is about 1mm and maximum carburizing rate is 23.6%. The anticarburizing effect of casting surface is greatly improved than that of zircon powder coating whose maximum carburizing rate is 67.9% and the carburizing layer thickness with respect to allowable upper limit of carbon content is greater than 2mm. The composite silicate powder containing zirconium coating substantially reduces the zircon powder which is expensive and radioactive and mainly dependent on imports. The coating can be used instead of pure zircon powder coating to effectively prevent metal-penetration and carburizing of resin-sand-casting surface of low carbon steel, significantly improve the foundry production environment and reduce the production costs.

  11. Low carbon steel corrosion damage prediction in rural and urban environments

    Directory of Open Access Journals (Sweden)

    Díaz, V.

    2003-12-01

    Full Text Available This paper presents an Artificial Neural Network (ANN model for the damage function of carbon steel, expressed in μm of corrosion penetration as a function of environmental variables. Working in the context of the Iberoamerican Atmospheric Corrosion Map Project, the experimental data comes as result of the corrosion of low alloy steel subtracts in three test sites in Uruguay, South America. In addition, we included experimental values obtained from short time kinetics studies, corresponding to special series from one of the sites. The ANN numerical model shows attractive results regarding goodness of fit and residual distributions. It achieves a RMSE value of 0.5 μm while a classical regression model lies in the range of 4.1 μm. Furthermore, a properly adjusted ANN model can be useful in the prediction of corrosion damage under different climatological and pollution conditions, while linear models cannot.

    Este artículo presenta la metodología de las redes neuronales artificiales (RNA como solución para el modelado de los valores experimentales obtenidos en los procesos de corrosión atmosférica. Se desarrolla el modelo de RNA para la función de daño, expresada en μm de penetración para el acero de bajo carbono en función de las variables medioambientales, en el contexto del Proyecto MICAT (Mapa Iberoamericano de Corrosión Atmosférica y programas de experimentación propios. Los datos experimentales son resultado de los estudios de calibración sobre sustratos ferrosos en tres sitios del territorio uruguayo, Sudamérica. Se incluyen, además, los valores experimentales obtenidos en los estudios de cinéticas iniciales, correspondientes a series especiales de cortos tiempos de exposición en una de las estaciones de ensayo. El modelo numérico de RNA muestra resultados con un valor de RMSE de 0,5 μm, en tanto el modelo de regresión clásico arroja un valor de 4,1 μm.

  12. Effects of Heat Treatment on the Microstructure and Mechanical Properties of Low-Carbon Steel with Magnesium-Based Inclusions

    Science.gov (United States)

    Zhang, Jian; Feng, Pei-Hsien; Pan, Yan-Chi; Hwang, Weng-Sing; Su, Yen-Hao; Lu, Muh-Jung

    2016-10-01

    The effects of heat treatment on the microstructure and mechanical properties of Mg-containing (7 ppm), low-carbon commercial steel (SS400) were investigated. Twenty different heat treatment paths were performed using a Gleeble 1500 thermomechanical simulator. It was observed by using an optical microscope that as the cooling rate increased and holding temperature decreased, the volume fractions of pearlite, Widmanstätten ferrite, and grain boundary allotriomorphs ferrite fell, whereas that of acicular ferrite (AF) increased. Quantifying the fractions of AF and other phases by using electron backscatter diffraction shows that the heat treatment path with a cooling rate of 20 K/s and holding temperature of 723 K (450 °C) induced the highest volume fraction (44 pct) of AF. As such, the toughness of the sample was increased 12.4 times compared with that observed in the sample containing 4 pct AF. Typical inclusions were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The results showed that the magnesium-based complex inclusions could act as nucleation sites of AF. Inclusions with a size of about 5 μm can serve as heterogeneous nucleation sites for AF. Mg-containing SS400 steel also has excellent hot-ductility in the temperature range of 973 K to 1273 K (700 °C to 1000 °C), and the minimum percentage reduction in area (R.A pct) value of around 63 pct at 1073 K (800 °C).

  13. Analysis of microstructural variation and mechanical behaviors in submerged arc welded joint of high strength low carbon bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Liangyun, E-mail: lly.liangyun@gmail.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Qiu, Chunlin; Zhao, Dewen; Gao, Xiuhua; Du, Linxiu [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2012-12-15

    Microstructural variation in high strength low carbon bainitic steel weldment was investigated in detail by means of optical microscope, transmission electron microscope and scanning electron microscope equipped with electron backscattered diffraction. The results showed that the welded joint has various microstructures such as acicular ferrite, coarse granular ferrite and fine polygonal ferrite. The martensite-austenite (MA) constituent has a variable structure in each sub-zone, which includes fully martensite and fully retained austenite. Meanwhile, the fine grained heat affected zone has higher content of retained austenite than the welded metal (WM) and coarse grained heat affected zone (CGHAZ). The orientation relationship between retained austenite and product phases in the WM and CGHAZ is close to Kurdjumov-Sachs relationship. However, the polygonal ferrite in the fine grained HAZ has no specific orientation relationship with the neighboring retained austenite. The toughness of the coarse grained region is much lower than that of the WM because the coarse bainite contains many large MA constituents to assist the nucleation of microcracks and coarse cleavage facet lowers the ability to inhibit the crack propagation.

  14. Microstructural Evolution During Cold Rolling and Subsequent Annealing in Low-Carbon Steel with Different Initial Microstructures

    Science.gov (United States)

    Ogawa, Toshio; Dannoshita, Hiroyuki; Maruoka, Kuniaki; Ushioda, Kohsaku

    2017-08-01

    Microstructural evolution during cold rolling and subsequent annealing of low-carbon steel with different initial microstructures was investigated from the perspective of the competitive phenomenon between recrystallization of ferrite and reverse phase transformation from ferrite to austenite. Three kinds of hot-rolled sheet specimens were prepared. Specimen P consisted of ferrite and pearlite, specimen B consisted of bainite, and specimen M consisted of martensite. The progress of recovery and recrystallization of ferrite during annealing was more rapid in specimen M than that in specimens P and B. In particular, the recrystallized ferrite grains in specimen M were fine and equiaxed. The progress of ferrite-to-austenite phase transformation during intercritical annealing was more rapid in specimen M than in specimens P and B. In all specimens, the austenite nucleation sites were mainly at high-angle grain boundaries, such as those between recrystallized ferrite grains. The austenite distribution was the most uniform in specimen M. Thus, we concluded that fine equiaxed recrystallized ferrite grains were formed in specimen M, leading to a uniform distribution of austenite.

  15. The Effect of Ultrafast Heating on Cold-Rolled Low Carbon Steel: Formation and Decomposition of Austenite

    Directory of Open Access Journals (Sweden)

    Felipe Manuel Castro Cerda

    2016-12-01

    Full Text Available The effect of heating rate on the formation and decomposition of austenite was investigated on cold-rolled low carbon steel. Experiments were performed at two heating rates, 150 °C/s and 1500 °C/s, respectively. The microstructures were characterized by means of scanning electron microscopy (SEM and electron backscattered diffraction (EBSD. Experimental evidence of nucleation of austenite in α/θ, as well as in α/α boundaries is analyzed from the thermodynamic point of view. The increase in the heating rates from 150 °C/s to 1500 °C/s has an impact on the morphology of austenite in the intercritical range. The effect of heating rate on the austenite formation mechanism is analyzed combining thermodynamic calculations and experimental data. The results provide indirect evidence of a transition in the mechanism of austenite formation, from carbon diffusion control to interface control mode. The resulting microstructure after the application of ultrafast heating rates is complex and consists of a mixture of ferrite with different morphologies, undissolved cementite, martensite, and retained austenite.

  16. Preparation Femtosecond Laser Prevention for the Cold-Worked Stress Corrosion Crackings on Reactor Grade Low Carbon Stainless Steel

    CERN Document Server

    John Minehara, Eisuke

    2004-01-01

    We report here that the femtosecond lasers like low average power Ti:Sapphire lasers, the JAERI high average power free-electron laser and others could peel off and remove two stress corrosion cracking (SCC) origins of the cold-worked and the cracking susceptible material, and residual tensile stress in hardened and stretched surface of low-carbon stainless steel cubic samples for nuclear reactor internals as a proof of principle experiment except for the third origin of corrosive environment. Because a 143 °C and 43% MgCl2 hot solution SCC test was performed for the samples to simulate the cold-worked SCC phenomena of the internals to show no crack at the laser-peered off strip on the cold-worked side and ten-thousands of cracks at the non-peeled off on the same side, it has been successfully demonstrated that the femtosecond lasers could clearly remove the two SCC origins and could resultantly prevent the cold-worked SCC.

  17. Effect of residual stress and hardening on grain boundary sliding in welds of low-carbon stainless steels with surface machining

    International Nuclear Information System (INIS)

    Mori, Hiroaki; Mochizuki, Masahito; Nishimoto, Kazutoshi; Katsuyama, Jinya

    2007-01-01

    To clarify the effects of residual stress and hardening on intergranular stress corrosion cracking (IGSCC) behavior in welds of low-carbon austenitic stainless steels with surface machining, residual stress and hardness were evaluated by 3-dimentional thermo elastic-plastic analysis and grain boundary sliding behavior was examined using a constant strain rate tensile test. It was revealed that grain boundary sliding occurred in the material at 561K by the tensile test with the numerically simulated tensile residual stress due to welding and surface machining. In addition, it was clarified that the grain boundary energy is raised by the grain boundary sliding. On the basis of these results, it was concluded that the cause of IGSCC in the welds of low-carbon austenitic stainless steel with surface hardening is the increase in grain boundary energy due to grain boundary sliding accelerated by residual stress of multi pass welding and surface hardening. (author)

  18. Effect of residual stress and hardening on grain boundary sliding in welds of low-carbon stainless steels with surface machining

    International Nuclear Information System (INIS)

    Mori, Hiroaki; Mochizuki, Masahito; Nishimoto, Kazutoshi; Katsuyama, Jinya

    2008-01-01

    To clarify the effects of residual stress and hardening on intergranular stress corrosion cracking (IGSCC) behavior in welds of low-carbon austenitic stainless steels with surface machining, residual stress and hardness were evaluated by 3-dimentional thermo elastic-plastic analysis and grain boundary sliding behavior was examined using a constant strain rate tensile test. It was revealed that grain boundary sliding occurred in the material at 561K by the tensile test with the numerically simulated tensile residual stress due to multi-pass welding and surface machining. In addition, it was clarified that the grain boundary energy is raised by the grain boundary sliding. On the basis of these results, it was concluded that the cause of IGSCC in the welds of low-carbon austenitic stainless steel with surface hardening is the increase in grain boundary energy due to grain boundary sliding induced by residual stress of multi pass welding and surface hardening. (author)

  19. Composition and B-H curve analysis of low carbon steel from Krakatau Steel company using VSM And EDX for magnet design of 13 MeV cyclotron

    International Nuclear Information System (INIS)

    Taufik; Emy Mulyani; Kusminarto; Slamet Santosa

    2012-01-01

    Cyclotron is one type of particle accelerator that accelerate particle in circular trajectory, in order to obtain high kinetic energy. One of the main components is the cyclotron magnet system that serves to form a cyclic particle trajectories and made of forged low carbon steel. In the magnet design, the selection of magnetic materials is very important in determining whether cyclotron magnet can operate properly or not and even can be optimal. That is why we need to test samples of magnetic materials from local production in this case two samples of material produced by PT Krakatau Steel (KS). Tests performed include testing of BH curve using VSM (Vibrating Sample Magnetometer) and material composition using EDX (Energy-dispersive X-ray spectroscopy). Obtained BH curve is used as material data in three-dimensional simulation using the Opera 3D with referee to magnetic model of Kirams 13. From this study it can be concluded that the position of the test object to the direction of the magnetic field induction gives different BH curve and the samples obtained from KS has a carbon content which is still high. The lower the carbon content in the iron will produce a better magnetic properties. Material samples analyzed will produce a field that is not optimal when it is used in a 13 MeV cyclotron magnet. (author)

  20. Microstructural characteristics and toughness of the simulated coarse grained heat affected zone of high strength low carbon bainitic steel

    International Nuclear Information System (INIS)

    Lan Liangyun; Qiu Chunlin; Zhao Dewen; Gao Xiuhua; Du Linxiu

    2011-01-01

    Highlights: → Total toughness can be separated into crack initiation energy and crack propagation energy. → Small effective grain size of lath martensite can improve the crack propagation energy. → MA constituent is mainly responsible for the low toughness of coarse bainite specimens. → High angle packet boundary in coarser bainite has few contributions to improving crack propagation energy. - Abstract: The correlation of microstructural characteristics and toughness of the simulated coarse grained heat affected zone (CGHAZ) of low carbon bainitic steel was investigated in this study. The toughness of simulated specimens was examined by using an instrumented Charpy impact tester after the simulation welding test was conducted with different cooling times. Microstructure observation and crystallographic feature analysis were conducted by means of optical microscope and scanning electron microscope equipped with electron back scattered diffraction (EBSD) system, respectively. The main microstructure of simulated specimen changes from lath martensite to coarse bainite with the increase in cooling time. The deterioration of its toughness occurs when the cooling time ranges from 10 to 50 s compared with base metal toughness, and the toughness becomes even worse when the cooling time increases to 90 s or more. The MA (martensite-austenite) constituent is primary responsible for the low toughness of simulated CGHAZ with high values of cooling time because the large MA constituent reduces the crack initiation energy significantly. For crack propagation energy, the small effective grain size of lath martensite plays an important role in improving the crack propagation energy. By contrast, high misorientation packet boundary in coarse bainite seems to have few contributions to the improvement of the toughness because cleavage fracture micromechanism of coarse bainite is mainly controlled by crack initiation.

  1. Impact Toughness of Subzones in the Intercritical Heat-Affected Zone of Low-Carbon Bainitic Steel

    Directory of Open Access Journals (Sweden)

    Zhenshun Li

    2018-06-01

    Full Text Available The subzones of the intercritical heat-affected zone (IC HAZ of low-carbon bainitic steel were simulated by using a Gleeble-3500 simulator to study the impact toughness. The results showed that the IC HAZ is not entirely brittle and can be further divided into three subzones according to the impact toughness or peak welding temperature; the invariant subzone heated between the critical transformation start temperature (Ac1 and 770 °C exhibited unchanged high impact toughness. Furthermore, an extremely low impact toughness was found in the embrittlement subzone, heated between 770 and 830 °C, and the reduction subzone heated between 830 °C and the critical transformation finish temperature (Ac3 exhibited toughness below that of the original metal. The size of the blocky martensite-austenite (M-A constituents was found to have a remarkable level of influence on the impact toughness when heated below 830 °C. Additionally, it was found that, once the constituent size exceeds a critical value of 3.0 µm at a peak temperature of 770 °C, the IC HAZ becomes brittle regardless of lath or twinned martensite constitution in the M-A constituent. Essentially, embrittlement was observed to occur when the resolved length of initial cracks (in the direction of the overall fracture formed as a result of the debonding of M-A constituents exceeding the critical Griffith size. Furthermore, when the heating temperature exceeded 830 °C, the M-A constituents formed a slender shape, and the impact toughness increased as the area fraction of the slender M-A constituents decreased.

  2. Impact Toughness of Subzones in the Intercritical Heat-Affected Zone of Low-Carbon Bainitic Steel.

    Science.gov (United States)

    Li, Zhenshun; Zhao, Xuemin; Shan, Dongri

    2018-06-06

    The subzones of the intercritical heat-affected zone (IC HAZ) of low-carbon bainitic steel were simulated by using a Gleeble-3500 simulator to study the impact toughness. The results showed that the IC HAZ is not entirely brittle and can be further divided into three subzones according to the impact toughness or peak welding temperature; the invariant subzone heated between the critical transformation start temperature ( A c1 ) and 770 °C exhibited unchanged high impact toughness. Furthermore, an extremely low impact toughness was found in the embrittlement subzone, heated between 770 and 830 °C, and the reduction subzone heated between 830 °C and the critical transformation finish temperature ( A c3 ) exhibited toughness below that of the original metal. The size of the blocky martensite-austenite (M-A) constituents was found to have a remarkable level of influence on the impact toughness when heated below 830 °C. Additionally, it was found that, once the constituent size exceeds a critical value of 3.0 µm at a peak temperature of 770 °C, the IC HAZ becomes brittle regardless of lath or twinned martensite constitution in the M-A constituent. Essentially, embrittlement was observed to occur when the resolved length of initial cracks (in the direction of the overall fracture) formed as a result of the debonding of M-A constituents exceeding the critical Griffith size. Furthermore, when the heating temperature exceeded 830 °C, the M-A constituents formed a slender shape, and the impact toughness increased as the area fraction of the slender M-A constituents decreased.

  3. Microstructural characteristics and toughness of the simulated coarse grained heat affected zone of high strength low carbon bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Lan Liangyun, E-mail: lly.liangyun@gmail.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Qiu Chunlin; Zhao Dewen; Gao Xiuhua; Du Linxiu [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2011-11-25

    Highlights: {yields} Total toughness can be separated into crack initiation energy and crack propagation energy. {yields} Small effective grain size of lath martensite can improve the crack propagation energy. {yields} MA constituent is mainly responsible for the low toughness of coarse bainite specimens. {yields} High angle packet boundary in coarser bainite has few contributions to improving crack propagation energy. - Abstract: The correlation of microstructural characteristics and toughness of the simulated coarse grained heat affected zone (CGHAZ) of low carbon bainitic steel was investigated in this study. The toughness of simulated specimens was examined by using an instrumented Charpy impact tester after the simulation welding test was conducted with different cooling times. Microstructure observation and crystallographic feature analysis were conducted by means of optical microscope and scanning electron microscope equipped with electron back scattered diffraction (EBSD) system, respectively. The main microstructure of simulated specimen changes from lath martensite to coarse bainite with the increase in cooling time. The deterioration of its toughness occurs when the cooling time ranges from 10 to 50 s compared with base metal toughness, and the toughness becomes even worse when the cooling time increases to 90 s or more. The MA (martensite-austenite) constituent is primary responsible for the low toughness of simulated CGHAZ with high values of cooling time because the large MA constituent reduces the crack initiation energy significantly. For crack propagation energy, the small effective grain size of lath martensite plays an important role in improving the crack propagation energy. By contrast, high misorientation packet boundary in coarse bainite seems to have few contributions to the improvement of the toughness because cleavage fracture micromechanism of coarse bainite is mainly controlled by crack initiation.

  4. Corrosion of low-carbon steel under environmental conditions at Hanford: Two-year soil corrosion test results

    International Nuclear Information System (INIS)

    Anantatmula, R.P.; Divine, J.R.

    1995-11-01

    At the Hanford Site, located in southeastern Washington state, nuclear production reactors were operated from 1944 to 1970. The handling and processing of radioactive nuclear fuels produced a large volume of low-level nuclear wastes, chemical wastes, and a combination of the two (mixed wastes). These materials have historically been packaged in US Department of Transportation (DOT) approved drums made from low-carbon steel, then handled in one of three ways: (A) Before 1970, the drums were buried in the dry desert soil. It was assumed that chemical and radionuclide mobility would be low and that the isolated, government-owned site would provide sufficient protection for employees and the public. (B) After 1970, the drums containing long-lived transuranic radionuclides were protected from premature failure by stacking them in an ordered array on an asphalt concrete pad in the bottom of a burial trench. The array was then covered with a large, 0.28-mm- (011-in.-) thick polyethylene tarp and the trench was backfilled with 1.3 m (4 ft) of soil cover. This burial method is referred to as soil-shielded burial . Other configurations were also employed but the soil-shielded burial method contains most of the transuranic drums. (C) Since 1987, US Department of Energy sites have complied with the Resource Conservation and Recovery Act of 1976 (RCRA) regulations. These regulations require mixed waste drums to be stored in RCRA compliant large metal sheds with provisions for monitoring. These sheds are provided with forced ventilation but are not heated or cooled

  5. Friction Stir Welding of Low-Carbon AISI 1006 Steel: Room and High-Temperature Mechanical Properties

    Science.gov (United States)

    Shunmugasamy, Vasanth C.; Mansoor, Bilal; Ayoub, Georges; Hamade, Ramsey

    2018-03-01

    Friction stir welding (FSW) is an ecologically benign solid-state joining process. In this work, FSW of low-carbon AISI 1006 steel was carried out to study the microstructure and mechanical properties of the resulting joints at both room temperature (RT) and 200 °C. In the parameter space investigated here, a rotational tool speed and translation feed combination of 1200 rpm and 60 mm/min produced a defect-free weld with balanced mechanical properties and a superior Vickers microhardness profile compared to all other conditions and to base metal (BM). At faster translation feeds (100 and 150 mm/min), wormhole defects were observed in the weld microstructure and were attributed to higher strain rate experienced by the weld zone. Under tensile loading, welded material exhibited yield strength that was up to 86 and 91% of the BM at RT and 200 °C, respectively. On the other hand, tensile strength of welded material was nearly similar to that of the base metal at both RT and 200 °C. However, at both temperatures the tensile ductility of the welded joints was observed to be significantly lower than the BM. Annealing of the 1200 rpm and 60 mm/min FSW specimen resulted in tensile strength of 102% compared to base material and 47% increase in the strain at failure compared to the as-welded specimen. The Charpy impact values revealed up to 62 and 53% increase in the specific impact energy for the 1200 rpm and 60 mm/min welded joints as compared with the BM.

  6. Proposal for the award of a contract for the supply of low-carbon steel sheets for the mqw quadrupole magnets

    CERN Document Server

    1999-01-01

    This document concerns the award of a contract for the supply of 1000 tonnes of low-carbon steel sheets for the MQW quadrupole magnets. Following a market survey carried out among 53 firms in 16 Member States, a call for tenders (IT-2619/SL/LHC) was sent on 24 September 1999 to three firms in two Member States. By the closing date, CERN had received two tenders. The Finance Committee is invited to agree to the negotiation of a contract with COCKERILL-SAMBRE (BE) for the supply of 1000 tonnes of low-carbon steel sheets for the MQW quadrupole magnets for a total amount of 894 780 euros (1 423 870 Swiss francs), subject to revision for contractual deliveries after 31 December 2001, with an option for the supply of up to 200 tonnes of additional low-carbon steel sheets, for a total amount of 178 956 euros (284 774 Swiss francs), subject to revision for contractual deliveries after 31 December 2001, bringing the total amount to a maximum of 1 073 736 euros (1 708 644 Swiss francs). The above amounts in Swiss franc...

  7. The efficiency of different types of wood charcoal on increasing carbon content on surfaces of low carbon steel in the pack carburizing process

    Directory of Open Access Journals (Sweden)

    Narongsak Thammachot

    2014-09-01

    Full Text Available The purpose of this research is to compare the efficiency of five types of wood charcoal, eucalyptus, coconut shell, tamarind, bamboo and cassava root in increasing carbon content on surfaces of low carbon steel by the pack carburizing process. The experiment for pack carburized low carbon steel (grade AISI 1020 was conducted by using the different wood charcoals as carburizers, mixed with 10% limestone (by weight as the energizer. The carburizing temperature of 950°C, and carburizing times of 2, 4 and 6 hours were used in the experiment. After grinding, the specimens in each case were checked for carbon content by optical emission spectroscopy. Micro-Vickers hardness testing and microstructure inspections were carried out. The results of the experiment showed that the efficiency of eucalyptus charcoal as the carburizer (for increasing carbon content on surfaces of low carbon steel was higher than that of tamarind, cassava root, coconut shell and bamboo charcoals. The averages for carbon content were: 1.16, 1.06, 0.97, 0.83 and 0.77% respectively.

  8. Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.

    Science.gov (United States)

    Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

    2013-05-01

    Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate.

  9. Fatigue crack growth behaviors in hot-rolled low carbon steels: A comparison between ferrite–pearlite and ferrite–bainite microstructures

    International Nuclear Information System (INIS)

    Guan, Mingfei; Yu, Hao

    2013-01-01

    The roles of microstructure types in fatigue crack growth behaviors in ferrite–pearlite steel and ferrite–bainite steel were investigated. The ferrite–bainite dual-phase microstructure was obtained by intermediate heat treatment, conducted on ferrite–pearlite hot-rolled low carbon steel. This paper presents the results from investigation using constant stress-controlled fatigue tests with in-situ scanning electron microscopy (SEM), fatigue crack growth (FCG) rate tests, and fatigue fractography analysis. Microscopy images arrested by in-situ SEM showed that the fatigue crack propagation in F–P steel could become unstable more ealier compared with that in F–B steel. The fatigue cracks in ferrite–pearlite were more tortuous and could propagate more freely than that in ferrite–bainite microstructures. However, frequent crack branching were observed in ferrite–bainite steel and it indicated that the second hard bainite phase effectively retarded the crack propagation. The variation of FCG rate (da/dN) with stress intensity factor range (ΔK) for F–P and F–B steels was discussed within the Paris region. It was shown that FCG rate of F–P steel was higher than that of F–B steel. Moreover, the fatigue fracture surface analysis proved that grain boundaries could also play a role in the resistance of crack propagation.

  10. Relationship between 0.2% proof stress and Vickers hardness of work-hardened low carbon austenitic stainless steel, 316SS

    International Nuclear Information System (INIS)

    Matsuoka, Saburo

    2004-01-01

    Stress corrosion cracking (SCC) occurs in shrouds and piping made of low carbon austenitic stainless steels at nuclear power plants. A work-hardened layer is considered to be one of the probable causes for this occurrence. The maximum Vickers hardness measured at the work-hardened layer is 400 HV. It is important to determine the yield strength and tensile strength of the work-hardened layer in the investigation on the causes of SCC. However, the tensile specimen cannot be obtained since the thickness of the work-hardened layer is as mall as several hundred μm, therefore, it is useful if we can estimate these strengths from its Vickers hardness. Consequently, we investigated the relationships between Vickers hardness versus yield strength and tensile strength using the results obtained on various steels in a series of Fatigue Data Sheets published by the National Institute for Materials Science and results newly obtained on a parent material and rolled materials (reduction of area: 10 - 50%, maximum hardness: 350 HV) for a low carbon stainless steel. The results showed that (1) the relationship between the 0.2% proof stress and the Vickers hardness can be described by a single straight line regardless of strength, structure, and rolling ratio, however, (2) the tensile strength is not correlated with the Vickers hardness, and the austenitic stainless steel in particular shows characteristics different from those of other steels. (author)

  11. Understanding the Effect of Ni on Mechanical and Wear Properties of Low-Carbon Steel from a View-Point of Electron Work Function

    Science.gov (United States)

    Lu, Hao; Huang, Xiaochen; Hou, Runfang; Li, D. Y.

    2018-04-01

    Electron work function (EWF) is correlated to intrinsic properties of metallic materials and can be an alternative parameter to obtain supplementary clues for guiding material design and modification. A higher EWF corresponds to a more stable electronic state, leading to higher resistance to any attempt to change the material structure and properties. In this study, effects of Ni as a solute with a higher EWF on mechanical, electrochemical, and tribological properties of low-carbon steel were investigated. Added Ni, which has more valence electrons, enhanced the electrons-nuclei interaction in the steel, corresponding to higher EWF. As a result, the Ni-added steel showed increased mechanical strength and corrosion resistance, resulting in higher resistances to wear and corrosive wear. Mechanism for the improvements is elucidated through analyzing EWF-related variations in Young's modulus, hardness, corrosion potential, and tribological behavior.

  12. The use of morinda citrifolia as a green corrosion inhibitor for low carbon steel in 3.5% NaCl solution

    Science.gov (United States)

    Kusumastuti, Rahayu; Pramana, Rakhmad Indra; Soedarsono, Johny W.

    2017-03-01

    The effect and mechanism of green corrosion inhibitor of Morinda Citrifolia (Noni) toward low carbon steel material has been researched. The general background is to develop the cheap and eco-friendly corrosion inhibitor based on components taken from tropical plants that grow +in Indonesia. This research aims to determine the effectiveness of the use of the extracts of noni as green corrosion inhibitor of carbon steel material in aggressive environment. The medium applied for this experiment is 3.5% natrium chloride solution. The variation of the concentration and immersion time duration has been applied as the experimental parameters. All the work was done at room temperature. The corrosion rate was measured by electrochemical polarization method with CMS 600-Gamry instruments and weight loss. The adsorption of inhibitor into the metal surface, which induced bonding formation after immersion was observed by using FTIR method. Inhibition mechanism was observed by polarization curves and fitted by the Langmuir adsorption models. The experimental results show that the higher concentration of inhibitor increasing the inhibition effect. The optimum inhibition is obtained at 3 ppm noni fruit extract, after immersion for about 288 hours. The corrosion rates obtained was 1.385 mpy, with the inhibitor efficiency of 76.92%. The monolayer film is formed coating the surface material as a result of mixed type corrosion inhibitor behavior of Noni. It can be concluded that this green inhibitor is effective to be used for low carbon steel material.

  13. Proposal for the award of a contract for the supply of low-carbon steel sheets for LHC resistive dipole magnets

    CERN Document Server

    2001-01-01

    This document concerns the award of a contract for the supply of 1 106 tonnes of low-carbon steel sheets for the MBW, MBXW and MCBW resistive dipole magnets for the LHC. Following a market survey (MS-2619/SL/LHC) carried out among 62 firms in sixteen Member States, a call for tenders (IT-2911/SL/LHC) was sent on 6 March 2001 to 11 firms in seven Member States. By the closing date, CERN had received one tender. The Finance Committee is invited to agree to the negotiation of a contract with the firm COCKERILL SAMBRE (BE), the only bidder, for the supply of 1 106 tonnes of low-carbon steel sheets for the MBW, MBXW and MCBW resistive dipole magnets for a total amount of 984 803 euros (1 511 328 Swiss francs), not subject to revision until 1 January 2003, with an option for the supply of up to 15% additional steel sheets, for a total amount of 147 720 euros (226 699 Swiss francs), not subject to revision until 1 January 2003, bringing the total amount to a maximum of 1 132 523 euros (1 738 027 Swiss francs), not s...

  14. Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

    Science.gov (United States)

    Loto, Roland Tolulope

    2018-03-01

    Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general), esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel's surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology.

  15. Corrosion behaviors and contact resistances of the low-carbon steel bipolar plate with a chromized coating containing carbides and nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Ching-Yuan; Ger, Ming-Der [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan, 335 (China); Wu, Min-Sheng [Department of Weapon System Engineering, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan, 335 (China)

    2009-08-15

    This work improved the surface performance of low-carbon steel AISI 1020 by a reforming pack chromization process at low temperature (700 C) and investigated the possibility that the modified steels are used as metal bipolar plates (BPP) of PEMFCs. The steel surface was activated by electrical discharge machining (EDM) with different currents before the chromizing procedure. Experimental results indicate that a dense and homogenous Cr-rich layer is formed on the EDM carbon steels by pack chromization. The chromized coating pretreated with electrical discharge currents of 2 A has the lowest corrosion current density, 5.78 x 10{sup -8} Acm{sup -2}, evaluated by potentiodynamic polarization in a 0.5 M H{sub 2}SO{sub 4} solution and the smallest interfacial contact resistance (ICR), 11.8 m{omega}-cm{sup 2}, at 140 N/cm{sup 2}. The carbon steel with a coating containing carbides and nitrides is promising for application as metal BPPs, and this report presents the first research in producing BPPs with carbon steels. (author)

  16. Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

    Directory of Open Access Journals (Sweden)

    Roland Tolulope Loto

    2018-03-01

    Full Text Available Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general, esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel’s surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology. Keywords: Corrosion, Inhibitor, Adsorption, Steel, Acid

  17. The Influence of Calcium Carbonate Composition and Activated Carbon in Pack Carburizing Low Carbon Steel Process in The Review of Hardness and Micro Structure

    Science.gov (United States)

    Hafni; Hadi, Syafrul; Edison

    2017-12-01

    Carburizing is a way of hardening the surface by heating the metal (steel) above the critical temperature in an environment containing carbon. Steel at a temperature of the critical temperature of affinity to carbon. Carbon is absorbed into the metal form a solid solution of carbon-iron and the outer layer has high carbon content. When the composition of the activator and the activated charcoal is right, it will perfect the carbon atoms to diffuse into the test material to low carbon steels. Thick layer of carbon Depending on the time and temperature are used. Pack carburizing process in this study, using 1 kg of solid carbon derived from coconut shell charcoal with a variation of 20%, 10% and 5% calcium carbonate activator, burner temperature of 950 0C, holding time 4 hours. The test material is low carbon steel has 9 pieces. Each composition has three specimens. Furnace used in this study is a pack carburizing furnace which has a designed burner box with a volume of 1000 x 600 x 400 (mm3) of coal-fired. Equipped with a circulation of oxygen from the blower 2 inches and has a wall of refractory bricks. From the variation of composition CaCO3, microstructure formed on the specimen with 20% CaCO3, better diffusion of carbon into the carbon steel, it is seen by the form marten site structure after quenching, and this indicates that there has been an increase of or adding carbon to in the specimen. This led to the formation of marten site specimen into hard surfaces, where the average value of hardness at one point side (side edge) 31.7 HRC

  18. Modification of the Structure of Low-Carbon Pipe Steel by Helical Rolling, and the Increase in Its Strength and Cold Resistance

    Science.gov (United States)

    Derevyagina, L. S.; Gordienko, A. I.; Pochivalov, Yu. I.; Smirnova, A. S.

    2018-01-01

    The paper reports the investigation results on the microstructure and mechanical properties of low-carbon pipe steel after helical rolling. The processing of the steel leads to the refinement of ferritic grains from 12 (for the coarse-grained state) to 5 μm, to the strengthening of ferrite by carbide particles, a decrease in the total fraction of perlite grains, a more uniform alternation of ferrite and perlite, and the formation of regions with bainitic structure. The mechanical properties of the steel have been determined in the conditions of static and dynamic loading in the range of test temperatures from +20 to-70°C. As a result of processing, the ultimate tensile strength increases (from 650 to 770 MPa at a rolling temperature from 920°C) and the viscoplastic properties at negative temperatures are improved significantly. The ductile-brittle transition temperature of the rolled steel decreases from-32 to-55°C and the impact toughness at the test temperature-40°C increases eight times compared to the initial state of the steel.

  19. Pathways to a low-carbon iron and steel industry in the medium-term : the case of Germany

    NARCIS (Netherlands)

    Arens, Marlene; Worrell, Ernst; Eichhammer, Wolfgang; Hasanbeigi, Ali; Zhang, Qi

    2017-01-01

    The iron and steel industry is a major industrial emitter of carbon dioxide globally and in Germany. If European and German climate targets were set as equal proportional reduction targets (referred to here as “flat” targets) among sectors, the German steel industry would have to reduce its carbon

  20. Technological change and industrial energy efficiency : Exploring the low-carbon transformation of the German iron and steel industry

    NARCIS (Netherlands)

    Arens, M.

    2017-01-01

    Climate change is a key challenge of our time. The iron and steel industry emits 6.5 % of global anthropogenic CO2 that is likely to drive global warming. Greenhouse gases, among these CO2, are to be reduced to 5-20% of today’s level in industrialised countries. Thus, the steel sector must make

  1. Boron content effect on the high-temperature plasticity of corrosion resistant low-carbon austenite type steels

    International Nuclear Information System (INIS)

    Gol'dshtejn, Ya.E.; Shmatko, M.N.; Chuvatina, S.N.

    1976-01-01

    With the concept that the state of grain and subgrain boundaries influences the hot plasticity of corrosion resistant steel as a starting point, the study was undertaken of the effect of boron microalloying up on the intergranular strength and of the action boron exerts upon the distribution (redistribution) of other phases present in austenitic 03Kh16N14M3 steels. An electron microscope study of the composition of redundant phases and that of the fine structure of steel have shown the effect of small additions of boron upon the hot plasticity of steel to be linked directly to its influence upon austenite disintegration and the precipitation along the boundaries of crystals of redundant phases in the course of hot plastic deformation. The action of boron upon the process plasticity of steel depends on the temperature and the rate of deformation which govern the kinetics of the precipitation of the redundant phases

  2. Effect of Strengthening Mechanism on Strain-Rate Related Tensile Properties of Low-Carbon Sheet Steels for Automotive Application

    Science.gov (United States)

    Das, Anindya; Biswas, Pinaki; Tarafder, S.; Chakrabarti, D.; Sivaprasad, S.

    2018-05-01

    In order to ensure crash resistance of the steels used in automotive components, the ensile deformation behavior needs to be studied and predicted not only under quasi-static condition, but also under dynamic loading rates. In the present study, tensile tests have been performed on four different automobile grade sheet steels, namely interstitial free steel, dual-phase 600 and 800, and a carbon manganese steel over the strain rate regime of 0.001-800/s. Apart from the variation in strength (which always increased with strain rate), the effect of strengthening mechanism on strain rate sensitivity and strain hardening behavior has been evaluated. Strain rate sensitivity was found to increase at high-strain rate regime for all the steels. Contribution of solid solution hardening on strain rate sensitivity at lower plastic strains was found to be higher compared to dislocation strengthening and second-phase hardening. However, precipitation hardening coupled with solid solution hardening produced the highest strain rate sensitivity, in C-Mn-440 steel at high strain rates. Different strain-rate-sensitive models which take into account the change in yield stress and strain hardening behavior with strain rate for ductile materials were used to predict the flow behavior of these sheet steels at strain rates up to 800/s.

  3. A low cycle fatigue model for low carbon manganese steel including the effect of dynamic strain aging

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhi Yong, E-mail: huangzy@scu.edu.cn [Sichuan University, School of Aeronautics and Astronautics, No.29 Jiuyanqiao Wangjiang Road, Chengdu 610064 (China); Wagner, Danièle [Université Paris Ouest Nanterre La Défense (France); Wang, Qing Yuan; Khan, Muhammad Kashif [Sichuan University, School of Aeronautics and Astronautics, No.29 Jiuyanqiao Wangjiang Road, Chengdu 610064 (China); Chaboche, Jean–Louis [ONERA, DMSM, 29 avenue de la Division Lecerc, F-92320, Chatillon (France)

    2016-01-27

    Carbon–manganese steel A48 (French standards) is used in steam generator pipes of the nuclear power plant where it is subjected to the cyclic thermal load. The Dynamic Strain Aging (DSA) influences the mechanical behavior of the steel in low cycle fatigue (LCF) at favorable temperature and strain rate. The peak stress of A48 steel experiences hardening–softening–hardening (HSH) evolution at 200 °C and 0.4% s{sup −1} strain rate in fatigue loading. In this study, isotropic and kinematic hardening rules with DSA effect have been modified. The HSH evolution of cyclic stress associated with cumulative plastic deformation has also been estimated.

  4. Improved fatigue behavior of low-carbon steel 20GL by applying ultrasonic impact treatment combined with the electric discharge surface alloying

    Energy Technology Data Exchange (ETDEWEB)

    Mordyuk, B.N., E-mail: mordyuk@imp.kiev.ua [Kurdyumov Institute for Metal Physics, NAS of Ukraine, 36 Academician Vernadsky blvd., UA-03142, Kyiv (Ukraine); Prokopenko, G.I.; Volosevich, P.Yu. [Kurdyumov Institute for Metal Physics, NAS of Ukraine, 36 Academician Vernadsky blvd., UA-03142, Kyiv (Ukraine); Matokhnyuk, L.E.; Byalonovich, A.V. [Pisarenko Institute for Strength of Materials, NAS of Ukraine, 2 Timiryazevs’ka str., UA-01014, Kyiv (Ukraine); Popova, T.V. [Ukrainian Research Institute Rail carriage building, 33 Prikhodko str., UA-39621, Kremenchuk (Ukraine)

    2016-04-06

    The effects of severe plastic deformation induced by ultrasonic impact treatment (UIT) and the electric discharge surface alloying (EDSA) with chromium on the stress-controlled fatigue response of low-carbon steel 20GL are studied. The surface microrelief and integrity were analyzed using light microscopy and scanning electron microscopy (SEM). The structural formations in the sub-surface layers were characterized by means of X-ray diffraction analysis and transmission electron microscopy (TEM). The steel specimens underwent UIT, and complex UIT+EDSA and UIT+EDSA+UIT processes demonstrate the fatigue strength magnitudes increased respectively by ~15, ~5 and ~30% on the base of 10{sup 7} cycles in comparison with that for the pristine specimen. SEM analysis of fracture surfaces reveals the subsurface crack nucleation in the UIT-processed specimens instead of superficial crack initiation observed in the pristine and EDSA-processed ones. TEM studies demonstrate that a dislocation-cell structure forms in ferrite grains and partial dissolution of cementite occurs in pearlite grains both at the surface after UIT and in the layer at a depth of 15–25 µm after the UIT+EDSA+UIT process. The enhanced fatigue strength and prolonged lifetime of the low-carbon steel specimens after UIT and UIT+EDSA+UIT processes are concluded to be associated with the subsurface crack nucleation achieved by the following factors: (i) minimized surface roughness and improved integrity of the modified layer; (ii) compressive residual stresses; and (iii) surface hardening coupled with the alloying by chromium and with the formation of the dislocation-cell structure containing the cell walls impenetrable to moving dislocations at cyclic loading.

  5. Effect of Boron and Titanium Addition on the Hot Ductility of Low-Carbon Nb-Containing Steel

    Science.gov (United States)

    Liu, Wei-Jian; Li, Jing; Shi, Cheng-Bin; Huo, Xiang-Dong

    2015-12-01

    The effect of boron and titanium addition on the hot ductility of Nb-containing steel was investigated using hot tensile tests. The fracture surface and the quenched longitudinal microstructure were examined by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that both steel samples had the similar change from 1,100°C to 700°C. The hot ductility of Nb-containing steel with boron and titanium addition was higher than the steel without boron and titanium in the temperature range of 900-750°C. Because the formation of intergranular ferrite was inhibited by solute boron segregating on the grain boundary, the formation of TiN changed the distribution of Nb- and boron-containing precipitates and improved the amount of intragranular ferrite.

  6. Influence of metallurgical phase transformation on crack propagation of 15-5PH stainless steel and 16MND5 low carbon steel

    International Nuclear Information System (INIS)

    Liu, J.

    2012-01-01

    This study focuses on the effects of phase transformations on crack propagation. We want to understand the changes of fracture toughness during welding. In this work, fracture toughness is expressed by J-integral. There are many experimental methods to obtain the critical toughness JIC but they are impractical for our investigation during phase transformation. That is the reason why we have proposed a method coupling mechanical tests, digital image correlation and finite element simulation. The fracture tests are implemented on pre-cracked single edge notched plate sample which is easy for machining and heat conduct during phase transformation. The tests are conducted at different temperatures until rupture. Digital image correlation gives us the displacement information on every sample. Each test is then simulated by finite element where the fracture toughness is evaluated by the method G-Theta at the crack propagation starting moment found by potential drop method and digital image correlation technical. Two materials have been studied, 15Cr-5Ni martensitic precipitation hardening stainless steel and 16MND5 ferritic low carbon steel. For these two materials, different test temperatures were chosen before, during and after phase transformation for testing and failure characterization of the mechanical behavior. Investigation result shows that metallurgical phase transformation has an influence on fracture toughness and further crack propagation. For 15-5PH, the result of J1C shows that the as received 15-5PH has higher fracture toughness than the one at 200 C. The toughness is also higher than the original material after one cycle heat treatment probably due to some residual austenite. Meanwhile, pure austenite 15-5PH at 200 C has higher fracture toughness than pure martensitic 15-5PH at 200 C. For 16MND5, the result also proves that the phase transformation affects fracture toughness. The as received material has bigger J1C than the situation where it was heated

  7. Mechanical and environmental effects on stress corrosion cracking of low carbon pipeline steel in a soil solution

    International Nuclear Information System (INIS)

    Contreras, A.; Hernández, S.L.; Orozco-Cruz, R.; Galvan-Martínez, R.

    2012-01-01

    Highlights: ► Mechanical and environmental effects on SCC of X52 steel were investigated. ► Slow strain rate tests (SSRT) were performed in a soil solution (NS4). ► Different levels of polarization potentials were applied to mitigating SCC. ► SSRT results indicate that X52 pipeline steel was susceptible to SCC. ► SCC susceptibility increase as the yielding and ultimate tensile stress increase. -- Abstract: Mechanical and environmental effects on stress corrosion cracking (SCC) susceptibility of X52 pipeline steel were investigated using slow strain rate tests (SSRT) performed in a glass autoclave containing a soil solution at strain rate of 1 × 10 −6 in./s at room temperature. Polarization potentials of −100, −200 and −400 mV referred to open circuit potential (OCP) was applied in order to establish the effectiveness of cathodic protection in mitigating SCC of X52 pipeline steel. Electrochemical impedance spectroscopy (EIS) tests and scanning electron microscopy (SEM) observations were done in order to analyze the SCC process. SSRT results indicate that X52 pipeline steel was susceptible to SCC. Susceptibility to SCC increase as the yielding stress (YS) and ultimate tensile stress (UTS) increase. The EIS results showed that the highest corrosion of the steel sample was obtained when the highest cathodic over potential was applied. SEM observations of these specimens showed a brittle type of fracture with transgranular appearance. The failure and SCC of X52 steel in soil solution was explained by hydrogen mechanism.

  8. The effect of β-FeOOH on the corrosion behavior of low carbon steel exposed in tropic marine environment

    International Nuclear Information System (INIS)

    Ma Yuantai; Li Ying; Wang Fuhui

    2008-01-01

    The atmospheric corrosion performance of carbon steel exposed in Wanning area, which located in the south part of China with tropic marine environment characters, was studied at different exposure periods (up to 2 years). To investigate the effect of β-FeOOH on the corrosion behavior of carbon steel in high chloride ion environment, rust layer was analyzed by using infrared spectroscopy, scanning electron microscope, X-ray diffraction, and the rusted steel was measured by electrochemical impedance spectroscopy method. The weight loss test indicated that the corrosion rate of carbon steel sharply increased during 6 months' exposure and gradually reduced after longer exposure. The results of rust analysis revealed that the underlying corrosion performance of the carbon steel was dependent on the inherent properties of the rust layers formed under different conditions such as composition and structure. Among all the iron oxide, β-FeOOH exerted significant influence. The presence of a monolayer of the rust as well as β-FeOOH accelerated the corrosion process during the initial exposure stage. EIS data implied that β-FeOOH in the inner layer was gradually consumed and transformed to γ-Fe 2 O 3 in the wet-dry cycle, which was beneficial to protect the substrate and reduced the corrosion rate

  9. The mechanism for the formation of boron ineffective zone and its effect on the properties of ultra low carbon bainitic steels

    International Nuclear Information System (INIS)

    Hsieh, Rongiuan; Wang, Shyichin; Liou, Horngyih.

    1993-01-01

    In the manufacturing of Ultra Low Carbon Bainitic(ULCB) steels, boron is a prerequisite alloying element to promote the desired bainitic transformation. In order to obtain this hardenability effect, boron must be in solution and segregate to austenite grain boundaries and thus decrease the contribution of boundary interfacial energy to ferrite nucleation. During the development of ULCB steels in CSC, a small boron ineffective zone was sometimes found at the center of steel plates. From EPMA and boron autoradiograph analysis, it was found that the formation of this boron ineffective zone was due to center line segregation of inclusions which strongly combined with boron and formed a boron free zone in its vicinity. The microstructure of the boron ineffective zone was conventional ferrite with strength much lower than that of its surrounding bainite. This resulted in the occurrence of separations (splits) in tensile and impact specimens. Also, it was found that the hydrogen induced cracking (HIC) has a propensity to propagate along the boron ineffective zone. in welding y-groove tests, a higher cold cracking sensitivity at this boron ineffective zone was also found

  10. Relationship Between Solidification Microstructure and Hot Cracking Susceptibility for Continuous Casting of Low-Carbon and High-Strength Low-Alloyed Steels: A Phase-Field Study

    Science.gov (United States)

    Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

    2013-08-01

    Hot cracking is one of the major defects in continuous casting of steels, frequently limiting the productivity. To understand the factors leading to this defect, microstructure formation is simulated for a low-carbon and two high-strength low-alloyed steels. 2D simulation of the initial stage of solidification is performed in a moving slice of the slab using proprietary multiphase-field software and taking into account all elements which are expected to have a relevant effect on the mechanical properties and structure formation during solidification. To account for the correct thermodynamic and kinetic properties of the multicomponent alloy grades, the simulation software is online coupled to commercial thermodynamic and mobility databases. A moving-frame boundary condition allows traveling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. From the simulation results, significant microstructure differences between the steel grades are quantitatively evaluated and correlated with their hot cracking behavior according to the Rappaz-Drezet-Gremaud (RDG) hot cracking criterion. The possible role of the microalloying elements in hot cracking, in particular of traces of Ti, is analyzed. With the assumption that TiN precipitates trigger coalescence of the primary dendrites, quantitative evaluation of the critical strain rates leads to a full agreement with the observed hot cracking behavior.

  11. Novel mechanism for the modification of Al2O3-based inclusions in ultra-low carbon Al-killed steel considering the effects of magnesium and calcium

    Science.gov (United States)

    Guo, Jing; Cheng, Shu-sen; Guo, Han-jie; Mei, Ya-guang

    2018-03-01

    Many researchers have explored the inclusion modification mechanism to improve non-metallic inclusion modifications in steelmaking. In this study, two types of industrial trials on inclusion modifications in liquid steel were conducted using ultra-low-carbon Al-killed steel with different Mg and Ca contents to verify the effects of Ca and Mg contents on the modification mechanism of Al2O3-based inclusions during secondary refining. The results showed that Al2O3-based inclusions can be modified into liquid calcium aluminate or a multi-component inclusion with the addition of a suitable amount of Ca. In addition, [Mg] in liquid steel can further reduce CaO in liquid calcium aluminate to drive its evolution into CaO-MgO-Al2O3 multi-component inclusions. Thermodynamic analysis confirmed that the reaction between [Mg] and CaO in liquid calcium aluminate occurs when the MgO content of liquid calcium aluminate is less than 3wt% and the temperature is higher than 1843 K.

  12. ANALYSIS ON THE BEHAVIOR OF PRECIPITATES IN ULTRA-THIN HOT STRIP OF PLAIN LOW CARBON STEEL PRODUCED BY COMPACT STRIP PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    H. Yu; Y.L. Kang; H.B. Dong; D.L. Liu; J. Fu

    2002-01-01

    This paper investigated the mechanism of precipitation and its influence upon prop-erties of ultra-thin hot strips of low carbon steel produced by CSP techniques usingexperiment and thermodynamics theory. The experimental results show that thereare lots of fine and dispersive precipitates in microstructures. By analysis, most ofaluminum nitrides are in grains, while coexisted precipitates of MnS are along grainboundaries. Coexisted precipitates compose cation-vacancy type oxides such as Al2O3in the core, while MnS is at the fringe of surface. The precipitation behavior of AlNand MnS in the hot strip is studied by thermodynamic calculation. At last, implica-tions between strengthening effect and techniques are analyzed using obtained solubilityproducts.

  13. Experimental study of laser-oxygen cutting of low-carbon steel using fibre and CO2 lasers under conditions of minimal roughness

    International Nuclear Information System (INIS)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyatyev, V B

    2014-01-01

    The results of an experimental study of laser-oxygen cutting of low-carbon steel using fibre and CO 2 lasers are generalised. The dependence of roughness of the cut surface on the cutting parameters is investigated, and the conditions under which the surface roughness is minimal are formulated. It is shown that for both types of lasers these conditions can be expressed in the same way in terms of the dimensionless variables – the Péclet number Pe and the output power Q of laser radiation per unit thickness of the cut sheet – and take the form of the similarity laws: Pe = const, Q = const. The optimal values of Pe and Q are found. We have derived empirical expressions that relate the laser power and cutting speed with the thickness of the cut sheet under the condition of minimal roughness in the case of cutting by means of radiation from fibre and CO 2 lasers. (laser technologies)

  14. Experimental comparison of laser energy losses in high-quality laser-oxygen cutting of low-carbon steel using radiation from fibre and CO2 lasers

    International Nuclear Information System (INIS)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyat'ev, V B

    2015-01-01

    We report a comparative experimental study of laseroxygen cutting of low-carbon steel using a fibre laser with a wavelength of 1.07 μm and a CO 2 laser with a wavelength of 10.6 μm at the sheet thickness of 3 – 16 mm. For the two lasers we have measured the dependence of the cutting speed on the radiation power and determined the cutting speed at which the surface roughness is minimal. The coefficient of laser radiation absorption in the laser cutting process is measured for these lasers at different values of the cutting speed and radiation power. It is found that the minimal roughness of the cut surface is reached at the absorbed laser energy per unit volume of the removed material, equal to 11 – 13 J mm -3 ; this value is the same for the two lasers and does not depend on the sheet thickness. (laser technologies)

  15. Material properties characterization of low carbon steel using TBW and PWHT techniques in smooth-contoured and U-shaped geometries

    International Nuclear Information System (INIS)

    Aloraier, Abdulkareem S.; Joshi, Suraj; Price, John W.H.; Alawadhi, Khaled

    2013-01-01

    This paper investigates the effects of the temper bead welding (TBW) technique and post weld heat treatment (PWHT) on mechanical properties of multi-layer welding on low carbon steel specimens using Charpy V-notch impact testing and tensile testing. Several samples of two different weld geometries, viz. (i) smooth-contoured, and (ii) U-shaped were made with multiple bead layers using both TBW and PWHT techniques. Impact testing showed that at room temperature and below, TBW gave an impact toughness in the Heat Affected Zone (HAZ) better than both PWHT and the parent material. At temperatures higher than the room temperature but below 60 °C, PWHT gave better impact toughness in the HAZ. Above 60 °C, both TBW and PWHT showed impact toughness lower than that of the parent material. In tensile testing, both TBW and PWHT weld metal specimens produced acceptable results; however, TBW gave yield and tensile strengths closer to that of the actual material than PWHT. -- Highlights: • Effects of post weld heat treatment (PWHT) and temper bead welding (TBW) on properties are tested. • Charpy V-notch impact and tensile testing was performed on multi-layer welding of low carbon steel. • At room temperature and below, TBW gave better impact toughness than both PWHT and parent material. • Above room temperature but below 60 °C, PWHT gave better impact toughness than TBW. • Above 60 °C, both TBW and PWHT showed impact toughness lower than that of parent material

  16. Welding-induced local maximum residual stress in heat affected zone of low-carbon austenitic stainless steel with machined surface layer and its influential factors

    International Nuclear Information System (INIS)

    Okano, Shigetaka; Ihara, Ryohei; Kanamaru, Daisuke; Mochizuki, Masahito

    2015-01-01

    In this study, the effects of work-hardening and pre-existing stress in the machined surface layer of low-carbon austenitic stainless steel on the welding-induced residual stress were experimentally investigated through the use of weld specimens with three different surface layers; as-cutout, mechanically-polished and electrolytically-polished. The high tensile and compressive stresses exist in the work-hardened surface layer of the as-cutout and mechanically-polished specimens, respectively. Meanwhile, no stress and work-hardened surface layer exist in the electrolytically-polished specimen. TIG bead-on-plate welding under the same welding heat input conditions was performed to introduce the residual stress into these specimens. Using these welded specimens, the distributions of welding-induced residual stress were measured by the X-ray diffraction method. Similarly, the distributions of hardness in welds were estimated by the Vickers hardness test. And then, these distributions were compared with one another. Based on the results, the residual stress in the weld metal (WM) is completely unaffected by the machined surface layer because the work-hardened surface layer disappears through the processes of melting and solidification during welding. The local maximum longitudinal tensile residual stress in the heat affected zone (HAZ) depends on the work-hardening but not on the existing stress, regardless of whether tensile or compressive, in the machined surface layer before welding. At the base metal far from WM and HAZ, the residual stress is formed by the addition of the welding-induced residual stress to the pre-existing stress in the machined surface layer before welding. The features of the welding-induced residual stress in low-carbon austenitic stainless steel with the machined surface layer and their influential factors were thus clarified. (author)

  17. The effect of the multi-pass non-circular drawing sequence on mechanical properties and microstructure evolution of low-carbon steel

    International Nuclear Information System (INIS)

    Lee, Jung Wan; Baek, Hyun Moo; Hwang, Sun Kwang; Son, Il-Heon; Bae, Chul Min; Im, Yong-Taek

    2014-01-01

    Highlights: • A multi-pass non-circular drawing sequence is proposed to make high-strength wires. • The sequence was designed and applied for a low-carbon steel wire up to the 10th pass. • Many LAGBs and small grain size of the wire produced by the sequence were obtained. • High plastic deformation was imposed on the wire, resulting in grain refinement. • The sequence made fine-grained wires with improved UTS, ductility and fatigue life. - Abstract: In this study, the multi-pass non-circular drawing sequence was investigated for manufacturing high-strength wires with better ductility in a simple continuous way without adding additional alloys and heat treatment considering the effect of microstructure evolution and die geometry of the sequence on the mechanical properties of low-carbon steel during the process. For this purpose, the non-circular drawing sequence was designed and applied up to the 10th pass at room temperature. Mechanical properties and microstructure evolution of the specimen processed by the sequence were investigated by tension, Vickers micro-hardness, electron backscattering diffraction (EBSD), and fatigue tests compared with those for the conventional wire-drawing process. From the EBSD results, the higher low angle grain boundaries length per unit area and smaller average grain size of the specimen processed by the non-circular drawing sequence were obtained than those of the specimen processed by the wire-drawing process for the 8th pass. These results indicated that more plastic deformation was imposed in the material by the non-circular drawing sequence, resulting in grain refinement of the deformed specimen compared to the wire-drawing process. It is demonstrated that the multi-pass non-circular drawing sequence could be beneficial in producing fine-grained wires with improved ultimate tensile strength, ductility, and fatigue property by simply changing drawing dies geometry of the conventional wire-drawing process

  18. Effect of Grain Orientation and Boundary Distributions on Hydrogen-Induced Cracking in Low-Carbon-Content Steels

    Science.gov (United States)

    Masoumi, Mohammad; Coelho, Hana Livia Frota; Tavares, Sérgio Souto Maior; Silva, Cleiton Carvalho; de Abreu, Hamilton Ferreira Gomes

    2017-08-01

    Hydrogen-induced cracking (HIC) causes considerable economic losses in a wide range of steels exposed to corrosive environments. The effect of crystallographic texture and grain boundary distributions tailored by rolling at 850 °C in three different steels with a body-centered cube structure was investigated on HIC resistance. The x-ray and electron backscattered diffraction techniques were used to characterize texture evolutions during the rolling process. The findings revealed a significant improvement against HIC based on texture engineering. In addition, increasing the number of {111} and {110} grains, associated with minimizing the number of {001} grains in warm-rolled samples, reduced HIC susceptibility. Moreover, the results showed that boundaries associated with low {hkl} indexing and denser packing planes had more resistance against crack propagation.

  19. Physical and chemical evaluation of the effect of a magnetic field on the electrodeposition of Ni in low carbon steel

    International Nuclear Information System (INIS)

    Campo G, G. A.

    2015-01-01

    In this study nickel coatings were obtained, with and without the presence of magnetic field at 60 degrees Celsius for 7, 12 and 17 minutes on substrates of AISI 1018 carbon steel, from a classical type Watts solution. The properties of the coatings were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy, hardness tester and roughness tester, the electrochemical behavior of the films was also studied through RP and EIE and also capacitance calculations, corrosion rate and thickness were made. In general, the magnetic field has a negative influence on the physical and chemical properties of an electrodeposited Ni steel AISI 1018. The details are discussed in this research. (Author)

  20. Analysis of low-carbon industrial symbiosis technology for carbon mitigation in a Chinese iron/steel industrial park: A case study with carbon flow analysis

    International Nuclear Information System (INIS)

    Zhang, Hui; Dong, Liang; Li, Huiquan; Fujita, Tsuyoshi; Ohnishi, Satoshi; Tang, Qing

    2013-01-01

    CO 2 mitigation strategies in industrial parks are a significant component of the Chinese climate change mitigation policy, and industrial symbiosis can provide specific CO 2 mitigation opportunity. Technology is important to support symbiosis, but few studies in China have focused on this topic at the industrial park level. This research presented a case study in a national iron and steel industrial park in China. Focus was given onto carbon mitigation through industrial symbiosis technology using substance flow analysis (SFA). Three typical iron and steel industry technologies, including coke dry quenching (CDQ), combined cycle power plant (CCPP), and CO 2 capture by slag carbonization (CCSC) were evaluated with SFA. Technology assessment was further conducted in terms of carbon mitigation potential and unit reduction cost. Compared with the Business as usual (BAU) scenario, application with CDQ, CCPP, and CCSC reduced the net carbon emissions by 56.18, 134.43, and 222.89 kg CO 2 per ton crude steel inside the industrial parks, respectively, including both direct and indirect emissions. Economic assessment revealed that the unit costs for the three technologies were also high, thereby necessitating national financial support. Finally, relevant policy suggestions and future concerns were proposed and discussed. - Highlights: • A typical carbon mitigation case study on China iron/steel industrial park. • Using carbon SFA to investigate mitigation effects of industrial symbiosis technology. • CCPP greatly reduced the indirect carbon emission embodied in power purchase. • CCSC reduced the carbon emission by distributing fixed carbon into by-product. • Specific low carbon-tech promotion policies fit to China was discussed and proposed

  1. Interpretation of quasi-static and dynamic tensile behavior by digital image correlation technique in TWinning Induced Plasticity (TWIP) and low-carbon steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Minju; Park, Jaeyeong; Sohn, Seok Su; Kim, Hyoung Seop [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kim, Nack J. [Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, Sunghak, E-mail: shlee@postech.ac.kr [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2017-05-02

    In this study, dynamic tensile tests were conducted on TWinning Induced Plasticity (TWIP) and low-carbon (LC) steel sheets at a strain rate of 1500–2000/s by using a split Hopkinson tensile bar, and deformation mechanisms related with improvement of dynamic tensile properties were investigated by a digital image correlation (DIC) technique. The dynamic tensile strength was higher than the quasi-static tensile strength in both TWIP and LC sheets, while the dynamic elongation was same to the quasi-static elongation in the TWIP sheet and was much lower than the quasi-static elongation in the LC sheet. According to the DIC results of the dynamically tensioned TWIP sheet, the homogeneous deformation occurred before the necking at the strain of 47.4%. This indicated that the dynamic deformation processes were almost similar to the quasi-static ones as the TWIP sheet was homogeneously deformed in the initial and intermediate deformation stages. This could be explained by deformation mechanisms including twinning, in consideration of favorable effect of increased twinning on tensile properties under the dynamic loading. On the other hand, the dynamically tensioned LC sheet was rapidly deformed and fractured as the necking was intensified in a narrow strain-concentrated region. The present DIC technique is an outstanding method for detailed dynamic deformation analyses, and provides an important idea for practical safety analyses of automotive steel sheets.

  2. Structure–mechanical property relationship in a high strength low carbon alloy steel processed by two-step intercritical annealing and intercritical tempering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, W.H. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States); Wang, X.L. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Venkatsurya, P.K.C. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States); Guo, H. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Shang, C.J., E-mail: cjshang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States)

    2014-06-01

    The influence of annealing and tempering temperature on the microstructure and mechanical properties was investigated in a low carbon alloy steel that was processed by a two-step intercritical annealing and intercritical tempering heat treatment. In general, the microstructure of the processed steel comprises intercritical lath-like ferrite, bainitic/martensitic lath and acicular-type retained austenite. The lower intercritical annealing temperature resulted in lower fraction of intercritical ferrite with finer grain size and consequently higher strength. On the other hand, the intercritical tempering temperature significantly influenced retained austenite content and precipitation. High fraction of retained austenite was obtained at a temperature slightly above Ac{sub 1} temperature and retained austenite content decreased with increase in tempering temperature. This behavior is attributed to the competition between the enrichment of Mn and Ni and the fraction of reversed austenite. Fine niobium carbide precipitates of size ∼2–6 nm and copper precipitates of size range ∼10–30 nm were obtained. The optimal intercritical annealing and tempering temperatures to obtain the product of tensile strength and elongation % of ∼30 GPa% were 780 °C and 660 °C, respectively and the volume fraction of retained austenite was ∼29%.

  3. Structure–mechanical property relationship in a high strength low carbon alloy steel processed by two-step intercritical annealing and intercritical tempering

    International Nuclear Information System (INIS)

    Zhou, W.H.; Wang, X.L.; Venkatsurya, P.K.C.; Guo, H.; Shang, C.J.; Misra, R.D.K.

    2014-01-01

    The influence of annealing and tempering temperature on the microstructure and mechanical properties was investigated in a low carbon alloy steel that was processed by a two-step intercritical annealing and intercritical tempering heat treatment. In general, the microstructure of the processed steel comprises intercritical lath-like ferrite, bainitic/martensitic lath and acicular-type retained austenite. The lower intercritical annealing temperature resulted in lower fraction of intercritical ferrite with finer grain size and consequently higher strength. On the other hand, the intercritical tempering temperature significantly influenced retained austenite content and precipitation. High fraction of retained austenite was obtained at a temperature slightly above Ac 1 temperature and retained austenite content decreased with increase in tempering temperature. This behavior is attributed to the competition between the enrichment of Mn and Ni and the fraction of reversed austenite. Fine niobium carbide precipitates of size ∼2–6 nm and copper precipitates of size range ∼10–30 nm were obtained. The optimal intercritical annealing and tempering temperatures to obtain the product of tensile strength and elongation % of ∼30 GPa% were 780 °C and 660 °C, respectively and the volume fraction of retained austenite was ∼29%

  4. Life cycle carbon emissions inventory of brick masonry and light steel framing houses in Brasilia: proposal of design guidelines for low-carbon social housing

    Directory of Open Access Journals (Sweden)

    Lucas Rosse Caldas

    Full Text Available Abstract This study evaluated the CO2eq emissions during the life cycle of two social housing projects in the city of Brasilia. A house of ceramic brick masonry was compared to a light steel framing one. The life cycle carbon emissions assessment (LCCO2A with a cradle-to-grave approach was used. The relation between the thermal performance of the wall systems and CO2eq emissions in the operational phase of the houses were evaluated using the DesignBuilder software. In addition, six scenarios composed of three CO2eq emission factors from the Brazilian electrical grid and two schedules of occupation of houses (full and part time were evaluated. The brick masonry house presented less CO2eq emissions than the light steel framing one. For both houses, the operational phase was the most significant regarding the total CO2eq emissions (50% to 70%, followed by the construction (20% to 30%, maintenance (11% to 20% and end-of-life (lower than 1% phases. The results also showed the importance of considering different CO2eq emission factors for the Brazilian context in the operational phase. Finally, based on the results obtained, design guidelines for low carbon social housing were proposed.

  5. Structure–property relationship in a 960 MPa grade ultrahigh strength low carbon niobium–vanadium microalloyed steel: The significance of high frequency induction tempering

    International Nuclear Information System (INIS)

    Xie, Z.J.; Fang, Y.P.; Han, G.; Guo, H.; Misra, R.D.K.; Shang, C.J.

    2014-01-01

    The present study describes the microstructure and precipitation behavior in an ultra-high strength low carbon niobium–vanadium microalloyed steel that was processed by quenching and high frequency induction tempering. Ultrahigh yield strength of ∼1000 MPa with high elongation of ∼15% and high low temperature toughness of 55 J (half thickness) at −40 °C was obtained after quenching from austenitization at 900 °C for 30 min, and tempering at 600 °C for 15 min by induction reheating with a reheating rate of ∼50 °C/s. While the yield strength increase on tempering was similar for both induction reheating and conventional reheating (electrical resistance reheating), there was ∼100% increase in low temperature toughness in induction reheated steel compared to the conventional reheating process. The underlying reason for the increase in toughness was attributed to the transformation of cementite film observed in conventional reheating and tempering to nanoscale cementite in induction reheating and tempering. The precipitation of nanoscale carbides is believed to significantly contribute to ultra-high strength, good ductility, and high toughness in the high frequency induction reheating and tempering process

  6. Investigation of magnetic, mechanical and microfailure behavior of ARMCO-type low carbon steel corroded in 3.5% NaCl-aqueous solution

    International Nuclear Information System (INIS)

    Ioakeimidis, E.K.; Kytopoulos, V.N.; Hristoforou, E.

    2013-01-01

    The corrosion effects of 3.5% NaCl aqueous solution on the tensile mechanical, micromagnetic Barkhausen emission (MBE) and microfailure behavior of low carbon steel were investigated. At first it was found that this steel shows a dramatic and consistent decrease of its ductility with time of corrosion. The ductility reduction as well as microfailure features obtained by Scanning Electron Microscopy (SEM)-fractographic analysis yields an acceptable evidence for the occurrence of the Hydrogen Environmental Embrittlement (HEE) phenomenon during the corrosion process. During tensile straining the MBE-signal increases monotically at an average constant rate towards necking point. This rate shows tendency to increase with corrosion time fact which helped to establish the existence of a corrosion-induced micromagnetic hardening rate effect. It was shown that the main contribution to this effect should be attributed primarily to the combined effect of the HEE and dislocation multiplication and to a lower extent to the formed magnetite (Fe 3 O 4 ) surface layers. Necking plasticity and MBE were correlated on the basis of combined stress bias and microvoid/microcracking-induced creation and rearangement of magnetic domains

  7. Investigation of magnetic, mechanical and microfailure behavior of ARMCO-type low carbon steel corroded in 3.5% NaCl-aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ioakeimidis, E.K., E-mail: evankostioa@gmail.com [Laboratory of Physical Metallurgy and Materials Technology, School of Mining and Metallurgical Engineering, N. T. U. A., Iroon Polytechniou 5, TK 157 73, Zografou Campus, Athens (Greece); Kytopoulos, V.N., E-mail: viktorkytopoulos@gmail.com [Laboratory of Strength of Materials and SEM, School of Applied Mathematics and Physical Science, N. T. U. A., Iroon Polytechniou 5, TK 157 73, Zografou Campus, Athens (Greece); Hristoforou, E., E-mail: eh@metal.ntua.gr [Laboratory of Physical Metallurgy and Materials Technology, School of Mining and Metallurgical Engineering, N. T. U. A., Iroon Polytechniou 5, TK 157 73, Zografou Campus, Athens (Greece)

    2013-10-20

    The corrosion effects of 3.5% NaCl aqueous solution on the tensile mechanical, micromagnetic Barkhausen emission (MBE) and microfailure behavior of low carbon steel were investigated. At first it was found that this steel shows a dramatic and consistent decrease of its ductility with time of corrosion. The ductility reduction as well as microfailure features obtained by Scanning Electron Microscopy (SEM)-fractographic analysis yields an acceptable evidence for the occurrence of the Hydrogen Environmental Embrittlement (HEE) phenomenon during the corrosion process. During tensile straining the MBE-signal increases monotically at an average constant rate towards necking point. This rate shows tendency to increase with corrosion time fact which helped to establish the existence of a corrosion-induced micromagnetic hardening rate effect. It was shown that the main contribution to this effect should be attributed primarily to the combined effect of the HEE and dislocation multiplication and to a lower extent to the formed magnetite (Fe{sub 3}O{sub 4}) surface layers. Necking plasticity and MBE were correlated on the basis of combined stress bias and microvoid/microcracking-induced creation and rearangement of magnetic domains.

  8. Experimental study on variations in Charpy impact energies of low carbon steel, depending on welding and specimen cutting method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaorui; Kang, Hansaem; Lee, Young Seog [Chung-Ang University, Seoul (Korea, Republic of)

    2016-05-15

    This paper presents an experimental study that examines variations of Charpy impact energy of a welded steel plate, depending upon the welding method and the method for obtaining the Charpy specimens. Flux cored arc welding (FCAW) and Gas tungsten arc welding (GTAW) were employed to weld an SA516 Gr. 70 steel plate. The methods of wire cutting and water-jet cutting were adopted to take samples from the welded plate. The samples were machined according to the recommendations of ASTM SEC. II SA370, in order to fit the specimen dimension that the Charpy impact test requires. An X-ray diffraction (XRD) method was used to measure the as-weld residual stress and its redistribution after the samples were cut. The Charpy impact energy of specimens was considerably dependent on the cutting methods and locations in the welded plate where the specimens were taken. The specimens that were cut by water jet followed by FCAW have the greatest resistance-to-fracture (Charpy impact energy). Regardless of which welding method was used, redistributed transverse residual stress becomes compressive when the specimens are prepared using water-jet cutting. Meanwhile, redistributed transverse residual stress becomes tensile when the specimens are prepared using wire cutting.

  9. Effects of the carbides precipitation on the hydrogen diffusion in a low carbon steel quenched and tempered

    International Nuclear Information System (INIS)

    Luppo, M.I.; Ovejero Garcia, J.

    1996-01-01

    Hydrogen diffusivity through steels at room temperature has been known to deviate considerably from the expected Arrhenius relation. This deviation is due to the attractive interactions between dissolved hydrogen and trapping sites (imperfections in the steel lattice). In a previous work it was shown that the apparent diffusion coefficients attain a minimum value in a fresh martensite and diffusivity increases in the same material tempered at 453 k during six hours. In order to explain this difference, the variation of hydrogen trapping sites with the tempering time, at the mentioned temperature, was studied by means of hydrogen permeation tests. Carbides precipitation was followed by means of the extraction replica technique using transmission electron microscopy. The hydrogen diffusivity obtained by the hydrogen permeation tests attained a minimum value in the quenched specimens and increased with increasing tempering time up to reach a constant value between three and six hours. This change in the hydrogen diffusivity was attributed to the trapping sites decrease promoted by carbides precipitation and their precipitation kinetics was described by an Avrami equation. (author). 4 refs., 4 figs

  10. Thermally Stable Ni-rich Austenite Formed Utilizing Multistep Intercritical Heat Treatment in a Low-Carbon 10 Wt Pct Ni Martensitic Steel

    Science.gov (United States)

    Jain, Divya; Isheim, Dieter; Zhang, Xian J.; Ghosh, Gautam; Seidman, David N.

    2017-08-01

    Austenite reversion and its thermal stability attained during the transformation is key to enhanced toughness and blast resistance in transformation-induced-plasticity martensitic steels. We demonstrate that the thermal stability of Ni-stabilized austenite and kinetics of the transformation can be controlled by forming Ni-rich regions in proximity of pre-existing (retained) austenite. Atom probe tomography (APT) in conjunction with thermodynamic and kinetic modeling elucidates the role of Ni-rich regions in enhancing growth kinetics of thermally stable austenite, formed utilizing a multistep intercritical ( Quench- Lamellarization- Tempering (QLT)-type) heat treatment for a low-carbon 10 wt pct Ni steel. Direct evidence of austenite formation is provided by dilatometry, and the volume fraction is quantified by synchrotron X-ray diffraction. The results indicate the growth of nm-thick austenite layers during the second intercritical tempering treatment (T-step) at 863 K (590 °C), with austenite retained from first intercritical treatment (L-step) at 923 K (650 °C) acting as a nucleation template. For the first time, the thermal stability of austenite is quantified with respect to its compositional evolution during the multistep intercritical treatment of these steels. Austenite compositions measured by APT are used in combination with the thermodynamic and kinetic approach formulated by Ghosh and Olson to assess thermal stability and predict the martensite-start temperature. This approach is particularly useful as empirical relations cannot be extrapolated for the highly Ni-enriched austenite investigated in the present study.

  11. Study and modeling of the ironing process on a multi-layered polymer coated low-carbon steel

    Science.gov (United States)

    Selles Canto, Miguel Angel

    The ironing process is the most crucial step in the manufacture of cans. Sheet steel covered by three polymer layers can be used as the starting material, but this coating must neither break nor fail in any manner in order to be considered as a viable and effective alternative to traditional practice. During ironing, the deformations are severe and high pressures exist at the tool-workpiece interface. Thickness reductions inherent in ironing require a large amount of surface generation. Deterioration of the coating in this delicate operation might enable direct contact of the stored food or drink with the metal. As can be appreciated, the key to the use of polymer-coated steel sheets in the manufacture of cans lies in the survival of these layers during the ironing process. Another important issue is the roughness of the newly-generated surface, because it should be possible to decorate the can without any difficulty. Changing the traditional manufacture of metallic containers such as cans and using this new coated material permits great reduction in environmental contaminants produced as a result of avoiding the formation of Volatile Organic Compounds (VOCs) during the manufacture of the polymer layers. This reduction is even greater because of not using additional lubricants due to the self-lubricanting property of the solid polymer coating layers during the drawing process. These objectives, together with the improvement of the mechanical characteristics and the adhesion of the painting or decorative priming, are realized by the use of the proposed material. In the existing bibliography about ironing processes on coated materials, some authors propose the use of the Upper Bound Theorem for modeling the material behavior. The present research shows for the first time the modeling of the ironing process on a three-layer polymer coated material. In addition, it takes into account the cases in which successful ironing is produced and those in which ones the ironing

  12. Continuous cooling transformations and microstructures in a low-carbon, high-strength low-alloy plate steel

    Science.gov (United States)

    Thompson, S. W.; Vin, D. J., Col; Krauss, G.

    1990-06-01

    A continuous-cooling-transformation (CCT) diagram was determined for a high-strength low-alloy plate steel containing (in weight percent) 0.06 C, 1.45 Mn, 1.25 Cu, 0.97 Ni, 0.72 Cr, and 0.42 Mo. Dilatometric measurements were supplemented by microhardness testing, light microscopy, and transmission electron microscopy. The CCT diagram showed significant suppression of polygonal ferrite formation and a prominent transformation region, normally attributed to bainite formation, at temperatures intermediate to those of polygonal ferrite and martensite formation. In the intermediate region, ferrite formation in groups of similarly oriented crystals about 1 μm in size and containing a high density of dislocations dominated the transformation of austenite during continuous cooling. The ferrite grains assumed two morphologies, elongated or acicular and equiaxed or granular, leading to the terms “acicular ferrite” and “granular ferrite,” respectively, to describe these structures. Austenite regions, some transformed to martensite, were enriched in carbon and retained at interfaces between ferrite grains. Coarse interfacial ledges and the nonacicular morphology of the granular ferrite grains provided evidence for a phase transformation mechanism involving reconstructive diffusion of substitutional atoms. At slow cooling rates, polygonal ferrite and Widmanstätten ferrite formed. These latter structures contained low dislocation densities and e-copper precipitates formed by an interphase transformation mechanism.

  13. Microstructural evaluation of a low carbon steel submitted to boriding treatment pre and post GTAW welding; Avaliacao microestrutural de um aco de baixo carbono submetido ao tratamento de boretacao pre e pos-soldagem GTAW

    Energy Technology Data Exchange (ETDEWEB)

    Pollnow, Edilson Nunes; Osorio, Alice Goncalves, E-mail: edilson.pollnow@hotmail.com, E-mail: osorio.alice@gmail.com [Universidade Federal de Pelotas (CDTec/UFPel), Pelotas, RS (Brazil). Centro de Desenvolvimento Tecnologico; Araujo, Douglas Bezerra de, E-mail: dbaraujo@ufu.br [Universidade Federal de Uberlandia (FEMEC/UFU), Uberlandia, MG (Brazil). Faculdade de Engenharia Mecanica; Passos, Thais Andrezza dos; Souza, Daniel, E-mail: thais.andrezza.passos@gmail.com, E-mail: danielsouza@furg.br [Universidade Federal do Rio Grande (EE/FURG), Rio Grande, RS (Brazil). Escola de Engenharia

    2017-04-15

    Studies on surface engineering area are given great importance due to the improvement that surface modifications provide to materials. With a global market that has the need to provide parts and equipment with extended service life and low cost, to support stringent requests and thus maintain its high performance, surface treatments may bring what was impossible into reality. Among the surface treatments that have received attention recently, we have the thermochemical process of boriding. The boriding process consists of saturate the surface of steels and metal alloys with boron. This saturation provides an increase in the surface properties not inherent to the base metal, such as hardness, resistance to abrasion and corrosion. Although the properties of boriding steels have already been studied, the effects that the boriding process perform on the steel during or after the welding processes are not known. Hence, it is the purpose of this study to evaluate the microstructure of a low carbon steel treated with boriding before and after GTAW welding. The results indicated poor metallurgical weldability of low carbon steel with boride layer, with the presence of solidification cracks. Nonetheless, the steel welded previous to boring treatment presented a more ductile nucleus, with harder surface. Although the values of hardness within the nucleus of the steel had dropped drastically at the welded zone after the boring, the surface of this steel showed higher values of hardness due to the boriding layer. This fact should be considered when applications where wear resistance is needed. (author)

  14. Fine structure characterization of martensite/austenite constituent in low-carbon low-alloy steel by transmission electron forward scatter diffraction.

    Science.gov (United States)

    Li, C W; Han, L Z; Luo, X M; Liu, Q D; Gu, J F

    2016-11-01

    Transmission electron forward scatter diffraction and other characterization techniques were used to investigate the fine structure and the variant relationship of the martensite/austenite (M/A) constituent of the granular bainite in low-carbon low-alloy steel. The results demonstrated that the M/A constituents were distributed in clusters throughout the bainitic ferrite. Lath martensite was the main component of the M/A constituent, where the relationship between the martensite variants was consistent with the Nishiyama-Wassermann orientation relationship and only three variants were found in the M/A constituent, suggesting that the variants had formed in the M/A constituent according to a specific mechanism. Furthermore, the Σ3 boundaries in the M/A constituent were much longer than their counterparts in the bainitic ferrite region. The results indicate that transmission electron forward scatter diffraction is an effective method of crystallographic analysis for nanolaths in M/A constituents. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  15. Building A Simulation Model For The Prediction Of Temperature Distribution In Pulsed Laser Spot Welding Of Dissimilar Low Carbon Steel 1020 To Aluminum Alloy 6061

    International Nuclear Information System (INIS)

    Yousef, Adel K. M.; Taha, Ziad A.; Shehab, Abeer A.

    2011-01-01

    This paper describes the development of a computer model used to analyze the heat flow during pulsed Nd: YAG laser spot welding of dissimilar metal; low carbon steel (1020) to aluminum alloy (6061). The model is built using ANSYS FLUENT 3.6 software where almost all the environments simulated to be similar to the experimental environments. A simulation analysis was implemented based on conduction heat transfer out of the key hole where no melting occurs. The effect of laser power and pulse duration was studied.Three peak powers 1, 1.66 and 2.5 kW were varied during pulsed laser spot welding (keeping the energy constant), also the effect of two pulse durations 4 and 8 ms (with constant peak power), on the transient temperature distribution and weld pool dimension were predicated using the present simulation. It was found that the present simulation model can give an indication for choosing the suitable laser parameters (i.e. pulse durations, peak power and interaction time required) during pulsed laser spot welding of dissimilar metals.

  16. The Effect of Simulated Thermomechanical Processing on the Transformation Behavior and Microstructure of a Low-Carbon Mo-Nb Linepipe Steel

    Science.gov (United States)

    Cizek, P.; Wynne, B. P.; Davies, C. H. J.; Hodgson, P. D.

    2015-01-01

    The present work investigates the transformation behavior of a low-carbon Mo-Nb linepipe steel and the corresponding transformation product microstructures using deformation dilatometry. The continuous cooling transformation (CCT) diagrams have been constructed for both the fully recrystallized austenite and that deformed in uniaxial compression at 1148 K (875 °C) to a strain of 0.5 for cooling rates ranging from 0.1 to about 100 K/s. The obtained microstructures have been studied in detail using electron backscattered diffraction complemented by transmission electron microscopy. Heavy deformation of the parent austenite has caused a significant expansion of the polygonal ferrite transformation field in the CCT diagram, as well as a shift in the non-equilibrium ferrite transformation fields toward higher cooling rates. Furthermore, the austenite deformation has resulted in a pronounced refinement in both the effective grain (sheaf/packet) size and substructure unit size of the non-equilibrium ferrite microstructures. The optimum microstructure expected to display an excellent balance between strength and toughness is a mix of quasi-polygonal ferrite and granular bainite (often termed "acicular ferrite") produced from the heavily deformed austenite within a processing window covering the cooling rates from about 10 to about 100 K/s.

  17. Strain-Annealing Based Grain Boundary Engineering to Evaluate its Sole Implication on Intergranular Corrosion in Extra-Low Carbon Type 304L Austenitic Stainless Steel

    Science.gov (United States)

    Pradhan, S. K.; Bhuyan, P.; Kaithwas, C.; Mandal, Sumantra

    2018-07-01

    Strain-annealing based thermo-mechanical processing has been performed to promote grain boundary engineering (GBE) in an extra-low carbon type austenitic stainless steel without altering the grain size and residual strain to evaluate its sole influence on intergranular corrosion. Single-step processing comprising low pre-strain ( 5 and 10 pct) followed by annealing at 1273 K for 1 hour have resulted in a large fraction of Σ3 n boundaries and significant disruption in random high-angle grain boundaries (RHAGBs) connectivity. This is due to the occurrence of prolific multiple twinning in these specimens as confirmed by their large twin-related domain and twin-related grain size ratio. Among the iterative processing, the schedule comprising two cycles of 10 and 5 pct deformation followed by annealing at 1173 K for 1 hour has yielded the optimum GBE microstructure with the grain size and residual strain akin to the as-received condition. The specimens subjected to the higher number of iterations failed to realize GBE microstructures due to the occurrence of partial recrystallization. Owing to the optimum grain boundary character distribution, the GBE specimen has exhibited remarkable resistance against sensitization and intergranular corrosion as compared to the as-received condition. Furthermore, the lower depth of percolation in the GBE specimen is due to the significant disruption of RHAGBs connectivity as confirmed from its large twin-related domain and lower fractal dimension.

  18. The Influence Of Nitridation Temperature And Time On The Surface Hardness Of AISI 1010 Low Carbon Steels Nitrided By Means Of Plasma Glow Discharge Technique

    International Nuclear Information System (INIS)

    Sujitno, Tjipto; Mujiman, Supardjono

    1996-01-01

    The results of the influence of nitridation temperature and time on the surface hardness of AISI 1010 low carbon steels nitrided by means of plasma glow discharge technique are presented in this paper. The results are the changing of surface hardiness, the changing of surface microstructure and the penetration profile depth. The experiment has been carried out at the temperature 400 o C, 450 o C, 500 o C, 550 o C, 570 o C and 600 o C, whereas the time is 5 minutes, 15 minutes, 40 minutes, 90 minutes and 180 minutes. All the experiments have been carried out at the optimum plasma density condition. The optimum plasma density condition is achieved at the pressure of p = 0.2 torr, when thr gas flow of nitrogen is 0.6 liter/minute and the distance of electrode plate is 4.5 cm. It was found that the optimum hardness of the surface was achieved at the temperature of 570 o C and the time of nitridation was 90 minutes, i.e. 190 KHN

  19. Experimental study of laser-oxygen cutting of low-carbon steel using fibre and CO{sub 2} lasers under conditions of minimal roughness

    Energy Technology Data Exchange (ETDEWEB)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyatyev, V B [S.A. Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2014-10-31

    The results of an experimental study of laser-oxygen cutting of low-carbon steel using fibre and CO{sub 2} lasers are generalised. The dependence of roughness of the cut surface on the cutting parameters is investigated, and the conditions under which the surface roughness is minimal are formulated. It is shown that for both types of lasers these conditions can be expressed in the same way in terms of the dimensionless variables – the Péclet number Pe and the output power Q of laser radiation per unit thickness of the cut sheet – and take the form of the similarity laws: Pe = const, Q = const. The optimal values of Pe and Q are found. We have derived empirical expressions that relate the laser power and cutting speed with the thickness of the cut sheet under the condition of minimal roughness in the case of cutting by means of radiation from fibre and CO{sub 2} lasers. (laser technologies)

  20. Parametric Study On The CW Nd: YAG Laser Cutting Quality Of 1.25 mm Ultra Low Carbon Steel Sheets Using O2 Assist Gas

    International Nuclear Information System (INIS)

    Salem, Hanadi G.; Abbas, Wafaa A.; Mansour, Mohy S.; Badr, Yehia A.

    2007-01-01

    There are many non-linear interaction factors responsible for the performance of the laser cutting process. Identification of the dominant factors that significantly affect the cut quality is important. In the current research, the gas pressure, laser power and scanning speed were selected as the cutting parameters. Effect of the cutting parameters on the cut quality was investigated, by monitoring the variation in hardness, oxide layer width and microstructural changes within the heat affected zone (HAZ). Results revealed that good quality cuts can be produced in ultra low carbon steel thin sheets, using CW Nd:YAG laser at a window of scanning speed ranging from 1100-1500 mm/min at a minimum heat input of 337watts under an assisting O2 gas pressure of 5 bar. Higher laser power resulted in either strengthening or softening in the HAZ surrounding the cut kerf. The oxide layer width is not affected by the energy density input but rather affected by the O2 gas pressure due to exothermal reaction

  1. The effect of microstructure and texture evolution on mechanical properties of low-carbon steel processed by the continuous hybrid process

    International Nuclear Information System (INIS)

    Hwang, Sun Kwang; Baek, Hyun Moo; Son, Il-Heon; Im, Yong-Taek; Bae, Chul Min

    2013-01-01

    In this paper, the continuous hybrid process is newly designed and applied for producing grain-refined long and large cross-section wires of low-carbon steel at high speed at room temperature. The initial specimen, with a diameter of 13 mm, continuously passes through the rolls, equal channel angular pressing (ECAP) dies, and wire-drawing dies in sequence during the process. The specimens deformed by the continuous hybrid process without and with the wire-drawing dies were obtained to investigate the role in the deformation separately. Their microstructures, textures, and mechanical properties were investigated by optical microscopy (OM), electron backscattering diffraction (EBSD), X-ray diffraction (XRD), tension, and Vickers micro-hardness tests and were compared with those for the case processed by the conventional wire-drawing process. According to the present investigation, the continuous hybrid process can more efficiently manufacture fine-grained wires with a strong shear texture in a continuous way than the conventional wire-drawing process can. In addition, the ultimate tensile strength value of the specimen processed by the continuous hybrid process was 23.9% higher, although the elongation was slightly lower than the one produced by the conventional wire-drawing process. The plastic deformation was mainly imposed by the ECAP dies, and the wire-drawing dies improve the dimensional accuracy and increase the local strain homogeneity in the continuous hybrid process. It is demonstrated that the continuous hybrid process might be beneficial in commercializing a continuous application of the severe plastic deformation process for producing grain-refined wires for industrial applications

  2. Microstructure and mechanical properties of a Ti-microalloyed low-carbon stainless steel treated by quenching-partitioning-tempering process

    Energy Technology Data Exchange (ETDEWEB)

    Xie, S.T., E-mail: xst-2007@163.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Liu, Z.Y. [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Wang, Z. [Research Institute, Baoshan Iron & Steel Co. Ltd., Shanghai 201900 (China); Wang, G.D. [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2016-06-15

    Quenching-partitioning-tempering (Q-P-T) process was used to treat a Ti-microalloyed low-carbon stainless steel after cold rolling. In addition to martensite, ferrite and retained austenite, TiN, coarse TiC, fine TiC, (Fe,Cr){sub 3}C and ultra-fine TiC precipitates were formed after the Q-P-T treatment. Based on field emission-scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations, thermodynamic, crystallographic and statistical analyses were used to reveal the precipitation behaviors of these particles. The effects of partitioning-tempering (P-T) temperature and time on the microstructure and mechanical properties of Q-P-T treated specimens were specially studied. The coarsening and spheroidization of (Fe,Cr){sub 3}C particles during P-T stage were obviously retarded by large Cr addition. The retained austenite was obtained significantly with appropriate P-T parameters. The precipitation of ultra-fine TiC particles in the martensite during the P-T stage at 500 °C induced a secondary hardening. - Highlights: • Some fine TiC with 30–70 nm precipitated in austenite during partial austenization. • A part of fine TiC had K-S OR with martensite after Q-P-T treatment. • A part of fine TiC had a OR specially deviating from K-S OR with martensite. • Coarsening and spheroidization of (Fe,Cr){sub 3}C were retarded during P-T stage. • Ultra-fine TiC with < 10 nm precipitated in martensite during P-T stage at 500 °C.

  3. Electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments

    Science.gov (United States)

    Mancio, Mauricio

    In reinforced concrete, a passive layer forms because of the alkaline conditions in the pores of the cement paste, where large concentrations of hydroxides create a solution with pH typically between 12 and 14. The corrosion resistance of the material depends on the characteristics and integrity of the passive film; however, currently very limited information is available about the passive films formed on carbon steel under such conditions. This work presents an electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments. More specifically, the study focuses on the characterization of the films formed on ASTM A36 steel reinforcing bar exposed to aqueous solutions that aim to reproduce the chemistry of the environment typically found within the cement paste. Electrochemical techniques such as cyclic potentiodynamic polarization curves, galvanostatic cathodic polarization and linear polarization resistance were employed, in addition to in-situ Surface Enhanced Raman Spectroscopy (SERS). The experimental setup was built in a way that SERS experiments could be performed simultaneously with potentiodynamic polarization curves, enabling a detailed analysis of the formation and reduction of the surface films as a function of applied potential. Three solutions with different pH levels were used for the polarization and SERS experiments, namely 0.55M KOH + 0.16M NaOH ([OH-]=0.71), 0.08M KOH + 0.02M NaOH ([OH-]=0.10) and 0.008M KOH + 0.002M NaOH ([OH-]=0.01). Additional NaOH solutions in which the pH was varied from 13 to 9 and the ionic strength from 10 -5 to 10-1 were prepared for a pilot study using linear polarization resistance. Results show that the features observed in the cyclic potentiodynamic polarization curves correlated well with the potential arrests observed in the GCP plots as well as with the changes observed in the SERS spectra, providing valuable information about

  4. Contribution of archaeological analogs to the estimation of average corrosion rates and long term corrosion mechanisms of low carbon steel in soil

    International Nuclear Information System (INIS)

    Neff, D.

    2003-11-01

    In the context of the French nuclear waste storage, a multi-barriers disposal is envisaged. Wastes could be put in metallic overpacks disposed in a clay soil. As these overpacks could be made of low carbon steel, it is important to understand the corrosion behaviour of this material in soil during period of several centuries. Indeed, it is necessary to consolidate the empirical data by a phenomenological approach. This includes laboratory experiments and modelling of the phenomenon which have to be validated and completed by the study of archaeological artefacts. This was the aim of this PhD-work. To this purpose, an analytical protocol has been elaborated: about forty archaeological artefacts coming from five dated sites (2. to 16. centuries) have been studied on cross section in order to observe on the same sample all the constituents of the system: metallic substrate/corrosion products/environment. The corrosion products are divided into two zones: the Dense Product Layer (DPL) in contact with the metal, and the Transformed Medium (TM) which are the corrosion products formed around soil minerals (quartz grains). The metallic substrate has been studied by the classical methods of materials science (optical and scanning electron microscope, energy and wavelength dispersive spectroscopies). It has been verified that despite their heterogeneity of structure and composition, they are all hypo-eutectoids steels that can contain phosphorous until 0.5 wt%. The corrosion products have been analysed by local structural analytical methods as micro-diffraction under synchrotron radiation (μXRD) and Raman micro-spectroscopy. These two complementary techniques and also the elemental composition analysis conducted to the characterisation of the corrosion forms. On the majority of the samples coming from four sites, the DPL are constituted by goethite including marbles of magnetite/maghemite. On the artefacts from the fifth site, a particular corrosion form has been identified

  5. Effect of carbon content on formation of bimodal microstructure and mechanical properties of low-carbon steels subjected to heavy-reduction single-pass hot/warm deformation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Won, E-mail: wonipark@iis.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Komaba 4-6-1, Meguro-ku 153-8505, Tokyo (Japan); Yanagimoto, Jun [Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku 153-8505, Tokyo (Japan)

    2014-06-01

    A compression test simulating heavy-reduction single-pass rolling was conducted to investigate the microstructural evolution based on the formation of a bimodal structure and the mechanical properties of 0.01% and 0.1% carbon steels and niobium steel. When thermomechanical processing was conducted near and above the critical transformation temperature (A{sub c3}), microstructures of all steels were significantly refined and consisted of equiaxed grains without elongated grains. Nevertheless, these microstructures showed weak or no formation of the bimodal structure or coarse grains with decreasing carbon content, while they showed bimodal structure formation when 0.2% carbon steel was used in our previous research. The average grain size of Nb steel was about 2 μm and its microstructure was uniformly refined. These may be attributed to a decrease in the number of nucleation sites with decreasing carbon content in low-carbon steels and the occurrence of nucleation at grain boundaries as well as in grain interiors in Nb steel during processing. Mechanical properties of all steels deformed above the critical transformation temperature exhibited high performance characteristics with superior strength and marked elongation. Their fractographs indicated ductile fracture, which was revealed by SEM observation after a tensile test.

  6. Proposal for the award of two contracts for the supply of fine-blanked low-carbon steel yoke laminations and inserts for the cold masses of the LHC superconducting dipole magnets

    CERN Document Server

    1999-01-01

    This document concerns the award of two contracts for the supply of 5 812 000 fine-blanked low-carbon steel yoke laminations, of two different types, and 5 800 000 inserts for the cold masses of the LHC superconducting dipole magnets. Following a market survey carried out among 70 firms in sixteen Member States and one firm in Japan, a call for tenders (IT-2467/LHC/LHC) was sent on 3 June 1999 to seven firms in four Member States. By the closing date, CERN had received five tenders. The Finance Committee is invited to agree to the negotiation of two contracts with: - FUG (DE) for the supply of 3 632 000 fine-blanked low-carbon steel yoke laminations and 3 625 000 inserts, which represents 5/8 of the total quantity required for the cold masses of the LHC superconducting dipole magnets, for a total amount of 2 525 563 euros, which at the exchange rate given in the tender correspond to 4 019 038 Swiss francs, subject to revision for contractual deliveries after 31 December 2001, with an option for the supply of ...

  7. Effect of nickel and MnS inclusions in the metal on the pitting corrosion of low-carbon stainless steels

    International Nuclear Information System (INIS)

    Frejman, L.I.; Nguen, The Dong; Volkov, D.E.; Konnov, Yu.P.

    1986-01-01

    The resistance to pitting corrosion of steels on the 03Kh17-03Kh18 base containing up to 20 % Ni at different levels of S and Mn impurities contamination is investigated. It is shown that up to 50 % of nickel introduced into ordinary steels with 5-6 % Ni is spent to compensate the resistance decrease caused by MnS inclusions. Full compensation is not attained even in the 10-20 %. Ni range in which nickel practically does not affect the resistance of neither ordinary, nor pure (without MnS) steels. Titanium introduction into ordinary steel on the Kh22N6 base permits to surpass the level of 03Kh17N3 pure steel resistance and attain the level of 03Kh17N6 pure steel almost by all characteristics (including passivated characteristics in sulfuric acid) besides pitting repassivity. In this property pure steels with Ni >or approx. 3 % surpass even the molybdenum containing 03Kh21NbM2T ordinary steel though they by far concede by passivation in sulfuric acid

  8. Study on mechanism of intergranular stress corrosion cracking and analysis of residual stress and work hardening in welds of low-carbon austenitic stainless steel with hard surface machining

    International Nuclear Information System (INIS)

    Mori, Hiroaki; Mochizuki, Masahito; Nishimoto, Kazutoshi; Toyoda, Masao; Katsuyama, Jinya

    2007-01-01

    In order to make clear the effects of residual stress and hardening on intergranular stress corrosion cracking (IGSCC) behavior in the welds of Type 316L low-carbon austenitic stainless steel with surface hardening, the residual stress and hardness in the butt-joint of pipes as a typical example of the actual structure were estimated and the grain boundary sliding was analyzed from the viewpoint of micro-deformation. On the basis of these results, the mechanism of IGSCC was discussed by the integrated knowledge between metallurgy and mechanics. The relationship between plastic strain and hardness in hard-machined surface near welds was clarified from the experimented relationship and the analysis method by the thermal elastic-plastic analysis. The distributions of hardness and residual stress with the actual surface machining could be simulated. It was made clear that grain boundary sliding occurred in the steel at 561K by a constant strain rate tensile test. From the comparison of grain boundary sliding behavior between solution treated specimen and cold-rolled one, it was found that the grain boundary sliding in cold-rolled one occurs in smaller strain conditions than that in as received one, and the amount of grain boundary sliding in cold-rolled one increases remarkably with increases in rolling reduction. In addition, it was clarified that the grain boundary energy is raised by the grain boundary sliding. On the basis of these results, it was concluded that the cause of IGSCC in the welds of Type 316L low-carbon austenitic stainless steel with surface hardening is the increase in grain boundary energy due to grain boundary sliding induced by residual stress of multi pass welding and surface hardening. (author)

  9. Friction Welding For Cladding Applications: Processing, Microstructure and Mechanical Properties of Inertia Friction Welds of Stainless Steel to Low Carbon Steel and Evaluation of Wrought and Welded Austenitic Stainless Steels for Cladding Applications in Acidchloride Service

    Science.gov (United States)

    Switzner, Nathan

    Friction welding, a solid-state joining method, is presented as a novel alternative process step for lining mild steel pipe and forged components internally with a corrosion resistant (CR) metal alloy for petrochemical applications. Currently, fusion welding is commonly used for stainless steel overlay cladding, but this method is costly, time-consuming, and can lead to disbonding in service due to a hard martensite layer that forms at the interface due to partial mixing at the interface between the stainless steel CR metal and the mild steel base. Firstly, the process parameter space was explored for inertia friction butt welding using AISI type 304L stainless steel and AISI 1018 steel to determine the microstructure and mechanical properties effects. A conceptual model for heat flux density versus radial location at the faying surface was developed with consideration for non-uniform pressure distribution due to frictional forces. An existing 1 D analytical model for longitudinal transient temperature distribution was modified for the dissimilar metals case and to account for material lost to the flash. Microstructural results from the experimental dissimilar friction welds of 304L stainless steel to 1018 steel were used to discuss model validity. Secondly, the microstructure and mechanical property implications were considered for replacing the current fusion weld cladding processes with friction welding. The nominal friction weld exhibited a smaller heat softened zone in the 1018 steel than the fusion cladding. As determined by longitudinal tensile tests across the bond line, the nominal friction weld had higher strength, but lower apparent ductility, than the fusion welds due to the geometric requirements for neck formation adjacent to a rigid interface. Martensite was identified at the dissimilar friction weld interface, but the thickness was smaller than that of the fusion welds, and the morphology was discontinuous due to formation by a mechanism of solid

  10. Elucidation of the effects of cementite morphology on damage formation during monotonic and cyclic tension in binary low carbon steels using in situ characterization

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Motomichi, E-mail: koyama@mech.kyushu-u.ac.jp [Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395 (Japan); Yu, Yachen; Zhou, Jia-Xi [Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395 (Japan); Yoshimura, Nobuyuki [Nippon Steel & Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu, Chiba 293-8511 (Japan); Sakurada, Eisaku [Nippon Steel & Sumitomo Metal Corporation, 5-3 Tokai, Aichi 476-8686 (Japan); Ushioda, Kohsaku [Nippon Steel & Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu, Chiba 293-8511 (Japan); Noguchi, Hiroshi [Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395 (Japan)

    2016-06-14

    The effects of the morphology and distribution of cementite on damage formation were studied using in situ scanning electron microscopy under monotonic and cyclic tension. To investigate the effects of the morphology/distribution of cementite, intergranular cementite precipitation (ICP) and transgranular cementite precipitation (TCP) steels were prepared from an ingot of Fe-0.017 wt% C binary alloy using different heat treatments. In all cases, the damage incidents were observed primarily at the grain boundaries. The damage morphology was dependent on the cementite morphology and loading condition. Monotonic tension in the ICP steel caused cracks across the cementite plates, located at the grain boundaries. In contrast, fatigue loading in the ICP steel induced cracking at the ferrite/cementite interface. Moreover, in the TCP steel, monotonic tension- and cyclic tension-induced intergranular cracking was distinctly observed, due to the slip localization associated with a limited availability of free slip paths. When a notch is introduced to the ICP steel specimen, the morphology of the cyclic tension-induced damage at the notch tip changed to resemble that across the intergranular cementite, and was rather similar to the monotonic tension-induced damage. The damage at the notch tip coalesced with the main crack, accelerating the growth of the fatigue crack.

  11. The EIS investigation of powder polyester coatings on phosphated low carbon steel: The effect of NaNO2 in the phosphating bath

    International Nuclear Information System (INIS)

    Jegdic, B.V.; Bajat, J.B.; Popic, J.P.; Stevanovic, S.I.; Miskovic-Stankovic, V.B.

    2011-01-01

    Highlights: → The effect of NaNO 2 on surface morphology of iron-phosphate coatings were determined. → Better corrosion stability of polyester coating on phosphated steel without NaNO 2 . → EIS results and microscopic examinations correlate well with adhesion measurements. - Abstract: The effect of different type of iron-phosphate coatings on corrosion stability and adhesion characteristic of top powder polyester coating on steel was investigated. Iron-phosphate coatings were deposited on steel in the novel phosphating bath with or without NaNO 2 as an accelerator. The corrosion stability of the powder polyester coating was evaluated by electrochemical impedance spectroscopy (EIS), adhesion by pull-off and NMP test, while surface morphology of phosphate coatings were investigated by atomic force microscopy (AFM). The adhesion and corrosion stability of powder polyester coatings were improved with pretreatment based on iron-phosphate coating deposited from NaNO 2 -free bath.

  12. Excellent mechanical properties and resistance to cavitation erosion for an ultra-low carbon CrMnN stainless steel through quenching and partitioning treatment

    Science.gov (United States)

    Zhou, Ze-an; Fu, Wan-tang; Zhu, Zhe; Li, Bin; Shi, Zhong-ping; Sun, Shu-hua

    2018-05-01

    The retained austenite content (RAC), the mechanical properties, and the resistance to cavitation erosion (CE) of the 00Cr13Mn8MoN steel after quenching and partitioning (Q&P) processing were investigated. The results show that the Q&P process affected the RAC, which reached the maximum value after partitioning at 400°C for 10 min. The tensile strength of the steel slightly decreased with increasing partitioning temperature and time. However, the elongation and product of strength and elongation first increased and then decreased. The sample partitioned at 400°C for 10 min exhibited the optimal property: a strength-ductility of 23.8 GPa·%. The resistance to CE for the 00Cr13Mn8MoN steel treated by the Q&P process was improved due to work hardening, spalling, and cavitation-induced martensitic transformation of the retained austenite.

  13. Bainite transformation of low carbon Mn-Si TRIP-assisted multiphase steels: influence of silicon content on cementite precipitation and austenite retention

    International Nuclear Information System (INIS)

    Jacques, P.; Catlin, T.; Geerlofs, N.; Kop, T.; Zwaag, S. van der; Delannay, F.

    1999-01-01

    Studies dealing with TRIP-assisted multiphase steels have emphasized the crucial role of the bainite transformation of silicon-rich intercritical austenite in the achievement of a good combination of strength and ductility. The present work deals with the bainite transformation in two steels differing in their silicon content. It is shown that both carbon enrichment of residual austenite and cementite precipitation influences the kinetics of the bainite transformation. A minimum silicon content is found to be necessary in order to prevent cementite precipitation from austenite during the formation of bainitic ferrite in such a way as to allow stabilisation of austenite by carbon enrichment. (orig.)

  14. Radioactive waste isolation in salt: Peer review of the Office of Nuclear Waste Isolation's draft report on a multifactor test design to investigate uniform corrosion of low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Paddock, R.A.; Lerman, A.; Ditmars, J.D.; Macdonald, D.D.; Peerenboom, J.P.; Was, G.S.; Harrison, W.

    1987-01-01

    This report documents Argonne National Laboratory's review of an internal technical memorandum prepared by Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) entitled Multifactor Test Design to Investigate Uniform Corrosion of Low-Carbon Steel in a Nuclear Waste Salt Repository Environment. The several major areas of concern identified by peer review panelists are important to the credibility of the test design proposed in the memorandum and are to adequately addressed there. These areas of concern, along with specific recommendations to improve their treatment, are discussed in detail in Sec. 2 of this report. The twenty recommendations, which were abstracted from those discussions, are presented essentially in the order in which they are introduced in Sec. 2.

  15. Stress corrosion inhibitors for type 18-10 stainless steels with low carbon content in hot and concentrated solutions of MgCl2. Study of some inorganic iodides

    International Nuclear Information System (INIS)

    Pinard, J.-L.

    1974-01-01

    Stress corrosion inhibitors for type Z2CN18-10 austenitic stainless steels with low carbon content in a solution of Cl 2 Mg at 105 deg C were investigated. It was established that iodides are the most adequate corrosion inhibitors because they react simultaneously upon the three main components of the alloy (Fe, Ni, Cr). A difference of behavior between I 2 Mg and the other iodides was observed (in electrochemistry and in simple stress corrosion experiments) and the influence of the metallic cation associated to I - was studied. The formation of the superficial film and the phenomena liable to occur at the interface film-corrosive solution were examined: film growth in MgCl 2 ; influence of certain substances added to the solution. A mechanism of inhibition by I - is suggested. It is similar to the mechanism proposed by BERGEN for the stress corrosion cracking by Cl - [fr

  16. Radioactive waste isolation in salt: Peer review of the Office of Nuclear Waste Isolation's draft report on a multifactor test design to investigate uniform corrosion of low-carbon steel

    International Nuclear Information System (INIS)

    Paddock, R.A.; Lerman, A.; Ditmars, J.D.; Macdonald, D.D.; Peerenboom, J.P.; Was, G.S.; Harrison, W.

    1987-01-01

    This report documents Argonne National Laboratory's review of an internal technical memorandum prepared by Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) entitled Multifactor Test Design to Investigate Uniform Corrosion of Low-Carbon Steel in a Nuclear Waste Salt Repository Environment. The several major areas of concern identified by peer review panelists are important to the credibility of the test design proposed in the memorandum and are to adequately addressed there. These areas of concern, along with specific recommendations to improve their treatment, are discussed in detail in Sec. 2 of this report. The twenty recommendations, which were abstracted from those discussions, are presented essentially in the order in which they are introduced in Sec. 2

  17. Experimental comparison of laser energy losses in high-quality laser-oxygen cutting of low-carbon steel using radiation from fibre and CO{sub 2} lasers

    Energy Technology Data Exchange (ETDEWEB)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyat' ev, V B [S.A. Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2015-09-30

    We report a comparative experimental study of laseroxygen cutting of low-carbon steel using a fibre laser with a wavelength of 1.07 μm and a CO{sub 2} laser with a wavelength of 10.6 μm at the sheet thickness of 3 – 16 mm. For the two lasers we have measured the dependence of the cutting speed on the radiation power and determined the cutting speed at which the surface roughness is minimal. The coefficient of laser radiation absorption in the laser cutting process is measured for these lasers at different values of the cutting speed and radiation power. It is found that the minimal roughness of the cut surface is reached at the absorbed laser energy per unit volume of the removed material, equal to 11 – 13 J mm{sup -3}; this value is the same for the two lasers and does not depend on the sheet thickness. (laser technologies)

  18. Electrochemical studies of the corrosion behavior of a low-carbon steel in aqueous chloride solutions simulating accident conditions of radioactive waste disposal

    International Nuclear Information System (INIS)

    Farvaque-Bera, A.M.; Leistikow, S.

    1991-01-01

    The fine-grained structural steel DIN W.Nr. 1.0566 was exposed to various sulfate and chloride-containing aqueous solutions, the latter ones simulating the potential accidental environment of water intrusion into a salt mine. By electrochemical measurements in salt brines, the following results were achieved: (1) The corrosion rate is highly dependent on salt brine composition, pH and temperature. (2) Active metal dissolution led to formation of shallow pits as surface corrosion phenomenon. Thus, the application of electrochemical techniques - under non-polarized as well as under potentiodynamic conditions - proved to be suitable for fast qualitative testing of the influence of various environmental parameters on steel corrosion. (orig.)

  19. Effect of Boron on the Strength and Toughness of Direct-Quenched Low-Carbon Niobium Bearing Ultra-High-Strength Martensitic Steel

    Science.gov (United States)

    Hannula, Jaakko; Kömi, Jukka; Porter, David A.; Somani, Mahesh C.; Kaijalainen, Antti; Suikkanen, Pasi; Yang, Jer-Ren; Tsai, Shao-Pu

    2017-11-01

    The effect of boron on the microstructures and mechanical properties of laboratory-control-rolled and direct-quenched 6-mm-thick steels containing 0.08 wt pct C and 0.02 wt pct Nb were studied. The boron contents were 24 ppm and a residual amount of 4 ppm. Two different finish rolling temperatures (FRTs) of 1093 K and 1193 K (820 °C and 920 °C) were used in the hot rolling trials to obtain different levels of pancaked austenite prior to DQ. Continuous cooling transformation (CCT) diagrams were constructed to reveal the effect of boron on the transformation behavior of these steels. Microstructural characterization was carried out using various microscopy techniques, such as light optical microscopy (LOM) and scanning electron microscopy-electron backscatter diffraction (SEM-EBSD). The resultant microstructures after hot rolling were mixtures of autotempered martensite and lower bainite (LB), having yield strengths in the range 918 to 1067 MPa with total elongations to fracture higher than 10 pct. The lower FRT of 1093 K (820 °C) produced better combinations of strength and toughness as a consequence of a higher degree of pancaking in the austenite. Removal of boron lowered the 34 J/cm2 Charpy-V impact toughness transition temperature from 206 K to 158 K (-67 °C to -115 °C) when the finishing rolling temperature of 1093 K (820 °C) was used without any loss in the strength values compared to the boron-bearing steel. This was due to the finer and more uniform grain structure in the boron-free steel. Contrary to expectations, the difference was not caused by the formation of borocarbide precipitates, as verified by transmission electron microscopy (TEM) investigations, but through the grain coarsening effect of boron.

  20. A Physical Model to Study the Effects of Nozzle Design on Dispersed Two-Phase Flows in a Slab Mold Casting Ultra-Low-Carbon Steels

    Science.gov (United States)

    Salazar-Campoy, María M.; Morales, R. D.; Nájera-Bastida, A.; Calderón-Ramos, Ismael; Cedillo-Hernández, Valentín; Delgado-Pureco, J. C.

    2018-04-01

    The effects of nozzle design on dispersed, two-phase flows of the steel-argon system in a slab mold are studied using a water-air model with particle image velocimetry and ultrasound probe velocimetry techniques. Three nozzle designs were tested with the same bore size and different port geometries, including square (S), special bottom design with square ports (U), and circular (C). The meniscus velocities of the liquid increase two- or threefold in two-phase flows regarding one-phase flows using low flow rates of the gas phase. This effect is due to the dragging effects on bubbles by the liquid jets forming two-way coupled flows. Liquid velocities (primary phase) along the narrow face of the mold also are higher for two-phase flows. Flows using nozzle U are less dependent on the effects of the secondary phase (air). The smallest bubble sizes are obtained using nozzle U, which confirms that bubble breakup is dependent on the strain rates of the fluid and dissipation of kinetic energy in the nozzle bottom and port edges. Through dimensionless analysis, it was found that the bubble sizes are inversely proportional to the dissipation rate of the turbulent kinetic energy, ɛ 0.4. A simple expression involving ɛ, surface tension, and density of metal is derived to scale up bubble sizes in water to bubble sizes in steel with different degrees of deoxidation. The validity of water-air models to study steel-argon flows is discussed. Prior works related with experiments to model argon bubbling in steel slab molds under nonwetting conditions are critically reviewed.

  1. Effects of carbon content and chromium segregation on creep rupture properties of low carbon and medium nitrogen type 316 stainless steel

    International Nuclear Information System (INIS)

    Nakazawa, Takanori; Fujita, Nobuhiro; Kimura, Hidetaka; Komatsu, Hajime; Kotoh, Hiroyuki; Kaguchi, Hitoshi.

    1997-01-01

    The creep rupture properties of type 316 stainless steels containing 0.005-0.022%C and 0.07%N have been investigated at 550degC and 600degC from the aspect of the grain boundary carbide precipitation which was changed with carbon content and chromium segregation. A small amount of carbide precipitated on grain boundaries during creep, because the solubility limit of the carbide is less than 0.005%. The creep rupture ductility of this steel increased with the reduction of carbon content from 0.010% to 0.005% while it decreased with increasing carbon content from 0.010% to 0.020%. Since the amount of grain boundary carbide decreased with reducing carbon content, the increase in ductility was due to the suppression of grain boundary embrittlement caused by the carbide. The creep rupture ductility of this steel was also improved by reducing chromium segregation. This behavior was attributed to the change in carbide morphology from concentrated type to dispersed one, which reduced the grain boundary embrittlement. (author)

  2. Determination of low carbon content in uranium

    International Nuclear Information System (INIS)

    Champeix, L.; Chevilliard, H.; Ponty, J.

    1960-01-01

    The method of carbon determination previously used for low carbon steels has been applied to uranium. Carbon contents down to a few tens p.p.m. and probably to a few p.p.m., can be determined with satisfactory precision, sensibility and accuracy. Reprint of a paper published in 'Memoires Scientifiques Rev. Metallurg.', LVI, n. 7, 1959, p. 657-662 [fr

  3. Dynamics of hydrogen induced blistering of a low carbon steel sheet by lamb waves analysis; Ramuha no teiryo kaiseki ni yoru hakubanteitansoko no suiso hare no dainamikkusu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Teruyoshi.; Takemoto, Mikio. [Aoyama Gakuin University, Tokyo (Japan). Faculty of Science and Engineering

    1999-06-15

    With the aim of studying the fracture dynamics of environmentally assisted fractures in thin plates, we developed a new source simulation method of the zeroth-order symmetric (or S{sub 0}-) Lamb wave using the experimental overall-transfer function of the system. The transfer function was determined by the time-domain deconvolution of detected S{sub 0}-Lamb component by the artificial fracture source of a compression -type PZT element whose vibration kinetics was estimated by the iteration so that the S{sub o}-waveform detected. Hydrogen induced blistering was found to be caused by the succession of fast Mode-I fracture with source rise times from 0.6 to 1.0{mu}s. The crack volume estimated by the source simulation corresponded to that of fine blistering with an opening displacement of 5{mu}m. As the estimated fracture kinetics of hydrogen blistering coincide with those of delayed fracture of high tension low alloy steel under tensile loading, the kinetics of first and micro-fractures and blistering induced by hydrogen gas precipitation appears to be independent on the hydrogen solubility and strength of steels, the applied stresses and the orientation of cracks. (author)

  4. Stability of retained austenite in multi-phase microstructure during austempering and its effect on the ductility of a low carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.J.; Ren, Y.Q.; Zhou, W.H. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Yang, J.R. [Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Shang, C.J., E-mail: cjshang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States)

    2014-05-01

    The contribution of multi-phase microstructure and retained austenite on mechanical properties of austempered and intercritical annealed Fe–0.23C–1.8Mn–1.35Si (wt%) steel was studied. The multi-phase microstructure comprised of intercritical ferrite (IF), bainite/martensite, and retained austenite. During austempering, the retained austenite was stabilized, which was studied using a combination of experimental (XRD, TEM) and thermodynamic analysis. The termination of bainitic transformation combined with carbon rejection into residual austenite during the second step austempering treatment is believed to be the underlying basis for stabilization of retained austenite. This led to significant increase in uniform and total elongation (25% and 36%, respectively) and the product of tensile strength and % elongation was 33 GPa%. The work hardening behavior of retained austenite exhibited a three-stage process such that necking was delayed. The increased work hardening rate is attributed to the multi-phase microstructure and TRIP effect.

  5. Three-dimensional characterization of bainitic microstructures in low-carbon high-strength low-alloy steel studied by electron backscatter diffraction

    International Nuclear Information System (INIS)

    Kang, J.S.; Seol, Jae-Bok; Park, C.G.

    2013-01-01

    We investigated the microstructural evolution of high strength low alloy steel, Fe–2.0Mn–0.15Si–0.05C (wt.%), by varying the continuous cooling rates from 1 K/s to 50 K/s using three-dimensional electron backscatter diffraction and transmission electron microscopy. Granular bainitic microstructure was prevalent under a slow cooling rate of 1–10 K/s, while lath-type bainite was dominant at a high cooling rate of 50 K/s. The acicular ferrite that was the major microstructure under the intermediate ranges of cooling rates between 10 K/s and 30 K/s was tangled with each other, leading to a three-dimensional interwoven structure with highly misoriented grains. Because of the formation of three-dimensional structures, we propose that the terms “acicular ferrite” and “bainitic ferrite,” which are currently used in steel, be replaced by the terms “interwoven acicular bainite” and “lath bainite,” respectively. Moreover, we also confirmed that the cooling rate is an important factor in determining whether bainitic microstructures occur in the form of granular bainite, interwoven bainite, or lath bainite. - Highlights: • The morphology of bainitic grains was characterized by 3D-EBSD. • The ‘interwoven bainite’ and ‘lath bainite’ were suggested. • Interwoven bainite consisted of lenticular plates that were interlinked in 3D regime. • The packets of lath bainite were aligned in a specific direction

  6. Three-dimensional characterization of bainitic microstructures in low-carbon high-strength low-alloy steel studied by electron backscatter diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kang, J.S. [Department of Materials Science and Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Technical Research Laboratories, POSCO, Pohang 790-300 (Korea, Republic of); Seol, Jae-Bok, E-mail: j.seol@mpie.de [Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, D-40237 Düsseldorf (Germany); Park, C.G. [Department of Materials Science and Engineering, POSTECH, Pohang 790-784 (Korea, Republic of)

    2013-05-15

    We investigated the microstructural evolution of high strength low alloy steel, Fe–2.0Mn–0.15Si–0.05C (wt.%), by varying the continuous cooling rates from 1 K/s to 50 K/s using three-dimensional electron backscatter diffraction and transmission electron microscopy. Granular bainitic microstructure was prevalent under a slow cooling rate of 1–10 K/s, while lath-type bainite was dominant at a high cooling rate of 50 K/s. The acicular ferrite that was the major microstructure under the intermediate ranges of cooling rates between 10 K/s and 30 K/s was tangled with each other, leading to a three-dimensional interwoven structure with highly misoriented grains. Because of the formation of three-dimensional structures, we propose that the terms “acicular ferrite” and “bainitic ferrite,” which are currently used in steel, be replaced by the terms “interwoven acicular bainite” and “lath bainite,” respectively. Moreover, we also confirmed that the cooling rate is an important factor in determining whether bainitic microstructures occur in the form of granular bainite, interwoven bainite, or lath bainite. - Highlights: • The morphology of bainitic grains was characterized by 3D-EBSD. • The ‘interwoven bainite’ and ‘lath bainite’ were suggested. • Interwoven bainite consisted of lenticular plates that were interlinked in 3D regime. • The packets of lath bainite were aligned in a specific direction.

  7. The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, Carlos A. [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)], E-mail: gorc74@yahoo.com; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)

    2008-12-01

    The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

  8. The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

    International Nuclear Information System (INIS)

    Gonzalez-Rodriguez, Carlos A.; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan

    2008-01-01

    The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

  9. Low carbon development. Key issues

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Frauke; Nordensvaard, Johan (eds.)

    2013-03-07

    This comprehensive textbook addresses the interface between international development and climate change in a carbon constrained world. It discusses the key conceptual, empirical and policy-related issues of low carbon development and takes an international and interdisciplinary approach to the subject by drawing on insights from across the natural sciences and social sciences whilst embedding the discussion in a global context. The first part explores the concept of low carbon development and explains the need for low carbon development in a carbon constrained world. The book then discusses the key issues of socio-economic, political and technological nature for low carbon development, exploring topics such as the political economy, social justice, financing and carbon markets, and technologies and innovation for low carbon development. This is followed by key issues for low carbon development in policy and practice, which is presented based on cross-cutting issues such as low carbon energy, forestry, agriculture and transportation. Afterwards, practical case studies are discussed from low carbon development in low income countries in Africa, middle income countries in Asia and Latin America and high income countries in Europe and North America.

  10. Guideposts for Low Carbon Finance

    International Nuclear Information System (INIS)

    Pizer, Billy

    2015-01-01

    The author proposes four guideposts for efficient low carbon finance: remove subsidies for high-carbon technologies, improve the cost-effectiveness of low-carbon subsidies, encourage private sector innovation and maintain transparent public policy tools that support cost-benefit accounting

  11. Microbiological Corrosion in Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    O. Medina–Custodio

    2009-01-01

    Full Text Available The Microbiologically Induced Corrosion affects several industries, such as oil industry where it is estimated that 20% to 30% pipes failures are related with microorganism . The chemical reactions generate ions transfer, this validate the use of electrochemical techniques for its analysis. Coupons submerged in a nutritional medium with presence and absence of three different microorganisms during two periods, 48 hours and 28 days we restudied. Polarization resistance (Rp and Electrochemical Impedance Spectroscopy (EIS techniques we re applied to determine the corrosivity of the systems. The results show a greater corrosive effect of abiotic system, this indicates a microorganisms protection effect to the metal, opposite to the first hypothesis. This result was ratified observing surfaces coupons by using Scanning Electron Microscopy (SEM technique. A possible mechanism based on Evans – Tafel graph is proposed to explain inhibitor microorganism effect.

  12. Maldives Low Carbon Development Strategy

    DEFF Research Database (Denmark)

    Fenhann, Jørgen Villy; Ramlau, Marianne

    This report presents the findings of a study for low carbon development strategy for Maldives. The study was implemented under the Memorandum of Understanding between the Ministry of Environment and Energy (MEE), Maldives and URC and was financed by Danida, Denmark’s development aid agency under...

  13. Overview of Low-carbon Economy Research

    OpenAIRE

    Fu, Hui

    2010-01-01

    The paper has a detailed literature review in low-carbon economy research of academy circle in our country from three aspects that are conception and connotation of low-carbon economy, necessity and urgency of developing low-carbon economy and path choice of realizing low-carbon economy in our country. Low-carbon economy is the “green economy†that obtains the maximum output by discharging minimum greenhouse gases with the main characteristics of “three low and three high†that are low ...

  14. Physical and chemical evaluation of the effect of a magnetic field on the electrodeposition of Ni in low carbon steel; Evaluacion fisica y quimica del efecto de un campo magnetico en la electrodeposicion de Ni en acero bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Campo G, G. A.

    2015-07-01

    In this study nickel coatings were obtained, with and without the presence of magnetic field at 60 degrees Celsius for 7, 12 and 17 minutes on substrates of AISI 1018 carbon steel, from a classical type Watts solution. The properties of the coatings were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy, hardness tester and roughness tester, the electrochemical behavior of the films was also studied through RP and EIE and also capacitance calculations, corrosion rate and thickness were made. In general, the magnetic field has a negative influence on the physical and chemical properties of an electrodeposited Ni steel AISI 1018. The details are discussed in this research. (Author)

  15. Effects of the carbides precipitation on the hydrogen diffusion in a low carbon steel quenched and tempered; Efectos de la precipitacion de carburos sobre la difusion del hidrogeno en un acero de bajo carbono templado y revenido

    Energy Technology Data Exchange (ETDEWEB)

    Luppo, M I; Ovejero Garcia, J [Comision Nacional de Energia Atomica, San Martin (Argentina). Unidad de Actividad Materiales

    1997-12-31

    Hydrogen diffusivity through steels at room temperature has been known to deviate considerably from the expected Arrhenius relation. This deviation is due to the attractive interactions between dissolved hydrogen and trapping sites (imperfections in the steel lattice). In a previous work it was shown that the apparent diffusion coefficients attain a minimum value in a fresh martensite and diffusivity increases in the same material tempered at 453 k during six hours. In order to explain this difference, the variation of hydrogen trapping sites with the tempering time, at the mentioned temperature, was studied by means of hydrogen permeation tests. Carbides precipitation was followed by means of the extraction replica technique using transmission electron microscopy. The hydrogen diffusivity obtained by the hydrogen permeation tests attained a minimum value in the quenched specimens and increased with increasing tempering time up to reach a constant value between three and six hours. This change in the hydrogen diffusivity was attributed to the trapping sites decrease promoted by carbides precipitation and their precipitation kinetics was described by an Avrami equation. (author). 4 refs., 4 figs.

  16. Strategies for Local Low-Carbon Development

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ohshita, Stephanie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Khanna, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Min, Hu [Energy Foundation China, Beijing (China); Xiulian, Hu [Energy Research Inst., Beijing (China)

    2012-11-14

    Cities around the world are implementing policies and programs with the goal to reduce greenhouse gas emissions, as well as save energy, reduce costs, and protect the local, regional, and global environment. In China, low-carbon development is a key element of the 12th Five Year Plan. Pilot low-carbon development zones have been initiated in five provinces and eight cities and many other locations around China also want to pursue a low-carbon development pathway. This booklet provides information for government officials, policy makers, program designers and implementers, provincial and city planners, and others who want an overview of the key options available for low-carbon development at local level. These Strategies for Local Low-Carbon Development draw from successful experiences from around the world. Information is provided for low-carbon actions that can be taken in the sectors of (1) Industry, (2) Buildings and Appliances, (3) Electric Power, (4) Consumption and Waste Management, (5) Transportation and Urban Form, and (6) Agriculture and Forestry. A description of each policy is provided along with information on the stakeholders involved in implementation, the conditions for successful implementation, the expected energy and carbon savings, and the policy cost-effectiveness. Case studies show how each policy has been implemented somewhere around the world. While there are many low-carbon options available for local implementation, this booklet aims to provide guidance on those that have been most successful, that have the largest impact, and that are cost-effective in order to support low-carbon development efforts in Chinese cities.

  17. Atmospheric corrosion of low carbon steel in a polar marine environment. Study of the effect of wind regime; Corrosion atmosferica del acero bajo en carbono en un ambiente marino polar. Estudio del efecto del regimen de vientos

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, S.; Chico, B.; Fuente, D. de la; Morcillo, M.

    2007-07-01

    The present work studies the atmospheric corrosion of carbon steel (UNE-EN 10130) in a sub-polar marine environment (Artigas Antarctic Scientific Base (BCAA), Uruguay) as a function of site atmospheric salinity and exposure time. A linear relationship is established between corrosion rate and airborne salinity deposition rate, valid in the deposition range encountered (125-225 mg Cl-l/m{sup 2}.d) and a bi logarithmic relationship established between corrosion and exposure time (1-4 years). Atmospheric salinity is related with the monthly wind speed average, based on the concept of the wind run. chloride ion deposition rates of less than 300 mg Cl-l/m{sup 2}.d are related with remote (oceanic) winds and coastal winds basically of speeds between 1-40 km/h, while higher deposition rates (300-700 mg Cl-/m{sup 2}.d) correspond to coastal marine winds of a certain persistence with speeds of between 41-80 km/h. (Author) 39 refs.

  18. Investigation on the parameter optimization and performance of laser cladding a gradient composite coating by a mixed powder of Co50 and Ni/WC on 20CrMnTi low carbon alloy steel

    Science.gov (United States)

    Shi, Yan; Li, Yunfeng; Liu, Jia; Yuan, Zhenyu

    2018-02-01

    In this study, a gradient composite coating was manufactured on 20CrMnTi alloy steel by laser cladding. The laser power, cladding scan velocity and powder flow rate were selected as influencing factors of the orthogonal cladding experiments. The influencing factors were optimized by the comprehensive analysis of Taguchi OA and TOPSIS method. The high significant parameters and the predicted results were confirmed by the ANOVA method. The macromorphology and microstructures are characterized by using laser microscope, SEM, XRD and microhardness tester. Comparison tests of wear resistance of gradient composite coating, 20CrMnTi cemented quenching sample and the 20CrMnTi sample were conducted on the friction-wear tester. The results show that the phases are γ-Co solid solution, Co3B, M23C6 and etc. The interlayers and wear-resisting layer also contain new hard phases as WC, W2C. The microhardness of the gradient coating was increased to 3 times as compared with that of the 20CrMnTi substrate. The wear resistance of the gradient composite coating and 20CrMnTi cemented quenching sample was enhanced to 36.4 and 15.9 times as compared with that of the 20CrMnTi.

  19. Aplicación del rayo láser de CO2 para soldar laminas de acero bajo carbono // Application of the ray laser of CO2 to weld sheets of steel low carbon

    Directory of Open Access Journals (Sweden)

    Enrique J. Martínez D

    1999-07-01

    very thin sheets is facilitated, that which difficultly is achieved withthe processes common of welding. This technique also presents the advantage that easily you can automate, producing weldings ofhigh precision with low contamination.The study consists on carrying out an investigation on the process of welding of thin sheets using a laser of CO2 of low power incontinuous way, focusing the laser with a lens of ZnSe and using industrial argon to control the atmosphere around the treated regionand to avoid the oxidation. To carry out the process, you design a device for ' to displace the sample at 45o with regard to thetrajectory of the ray laser in precise form; the welding was carried out to it collides and without material contribution.The work was carried out on sheets of steel of low coal of caliber 24 and 26. The welded samples were subjected to: tractionrehearsal, visual analysis, analysis metalográfico and microdureza tests. The obtained results show that it can be carried out theprocess easily, by means of the control of the most important variables, in such a way that once established, the operator doesn't needa great experience in the handling of this technique to carry out the process with high quality. The carried out analyses confirm thatby means of this technique it is possible to obtain uniform welding cords, with good mechanical properties.Key words: Welding, laser.

  20. The Future of Low-Carbon Electricity

    Energy Technology Data Exchange (ETDEWEB)

    Greenblatt, Jeffery B. [Energy Analysis and Environmental Impacts Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720,; Brown, Nicholas R. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, Pennsylvania 16802; Slaybaugh, Rachel [Department of Nuclear Engineering, University of California, Berkeley, California 94720; Wilks, Theresa [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Stewart, Emma [Lawrence Livermore National Laboratory, Livermore, California 94550; McCoy, Sean T. [Global Security, E Program, Lawrence Livermore National Laboratory, Livermore, California 94550

    2017-10-17

    We review future global demand for electricity and major technologies positioned to supply it with minimal greenhouse gas (GHG) emissions: renewables (wind, solar, water, geothermal, and biomass), nuclear fission, and fossil power with CO2 capture and sequestration. We discuss two breakthrough technologies (space solar power and nuclear fusion) as exciting but uncertain additional options for low-net GHG emissions (i.e., low-carbon) electricity generation. In addition, we discuss grid integration technologies (monitoring and forecasting of transmission and distribution systems, demand-side load management, energy storage, and load balancing with low-carbon fuel substitutes). For each topic, recent historical trends and future prospects are reviewed, along with technical challenges, costs, and other issues as appropriate. Although no technology represents an ideal solution, their strengths can be enhanced by deployment in combination, along with grid integration that forms a critical set of enabling technologies to assure a reliable and robust future low-carbon electricity system.

  1. Financing low carbon energy access in Africa

    International Nuclear Information System (INIS)

    Gujba, Haruna; Thorne, Steve; Mulugetta, Yacob; Rai, Kavita; Sokona, Youba

    2012-01-01

    Modern energy access in Africa is critical to meeting a wide range of developmental challenges including poverty reduction and the Millennium Development Goals (MDGs). Despite having a huge amount and variety of energy resources, modern energy access in the continent is abysmal, especially Sub-Saharan Africa. Only about 31% of the Sub-Saharan African population have access to electricity while traditional biomass energy accounts for over 80% of energy consumption in many Sub-Saharan African countries. With energy use per capita among the lowest in the world, there is no doubt that Africa will need to increase its energy consumption to drive economic growth and human development. Africa also faces a severe threat from global climate change with vulnerabilities in several key areas or sectors in the continent including agriculture, water supply, energy, etc. Low carbon development provides opportunities for African countries to improve and expand access to modern energy services while also building low-emission and climate-resilient economies. However, access to finance from different sources will be critical in achieving these objectives. This paper sets out to explore the financial instruments available for low carbon energy access in Africa including the opportunities, markets and risks in low carbon energy investments in the continent. - Highlights: ► Access to finance will be critical to achieving low carbon energy access in Africa. ► Domestic finance will be important in leveraging private finance. ► Private sector participation in modern and clean energy in Africa is still low. ► Many financing mechanisms exist for low carbon energy access in Africa. ► The right institutional frameworks are critical to achieving low carbon energy access in Africa.

  2. Steel

    International Nuclear Information System (INIS)

    Zorev, N.N.; Astafiev, A.A.; Loboda, A.S.; Savukov, V.P.; Runov, A.E.; Belov, V.A.; Sobolev, J.V.; Sobolev, V.V.; Pavlov, N.M.; Paton, B.E.

    1977-01-01

    Steels also containing Al, N and arsenic, are suitable for the construction of large components for high-power nuclear reactors due to their good mechanical properties such as good through-hardening, sufficiently low brittleness conversion temperature and slight displacement of the latter with neutron irradiation. Defined steels and their properties are described. (IHOE) [de

  3. Optimization of fatigue damage indication in ferromagnetic low carbon steel

    Czech Academy of Sciences Publication Activity Database

    Tomáš, Ivan; Kovářík, O.; Kadlecová, Jana; Vértesy, G.

    2015-01-01

    Roč. 26, č. 9 (2015), 095603 ISSN 0957-0233 R&D Projects: GA ČR GB14-36566G Institutional support: RVO:68378271 Keywords : fatigue * residual lifetime * magnetic non-destructive evaluation * ferromagnetic construction materials Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.492, year: 2015

  4. Evaluation of new multiaxial damage parameters on low carbon steel

    Directory of Open Access Journals (Sweden)

    A. S. Cruces

    2017-07-01

    Full Text Available Most mechanical components are subjected to the complex fatigue loading conditions, where both amplitude and direction of loading cycles change over the time. The estimation of damage caused by these complex loading scenarios are often done by simplified uniaxial fatigue theories, which ultimately leads to higher factor of safety during the final design considerations. Critical plane-based fatigue theories have been considered more accurate for computing the fatigue damage for multiaxial loading conditions in comparison to energy-based and equivalent stress-based theories. Two recently developed fatigue theories have been evaluated in this work for the available test data. Test data includes significant amount of biaxial load paths.

  5. Dislocation structure and cold resistance of low-carbon steel

    International Nuclear Information System (INIS)

    Gul', Yu.P.; Karnaukh, A.I.

    1975-01-01

    In the formation of the dislocation structure of a small (10%) deformation, the determining effect on the cold brittleness temperature is exerted by the degree of uniformity in the distribution of dislocations and microvolumes. The overall density of the dislocations is of secondary importance here. By pretreatment to achieve more uniform distribution and dispersion of particles of the excess phase, the degree of uniformity of dislocation distribution in microvolumes can be increased, the cold brittleness temperature lowered and the effect of various deformation patterns on resistance to cold counterbalanced. The formation of a cell-type dislocation structure in the case of a nonuniform distribution of relatively large particles of the excess phase and in that of a large overall density of dislocations does not result in low brittleness temperatures. The formation of a cell-type dislocation structure in the case of uniform distribution of particles of the excess phase and of a comparatively small overall density of dislocations is accompanied by a very pronounced decrease in cold brittleness temperature not only by comparison with other types of dislocation structure but also with the normalized state. At the same time the formation of this kind of a cell structure leads to a substantial (factor of 2-5) increase in resistance to plastic deformation. The prerequisites for obtaining an optimum dislocation are fulfilled either by a combination of hardening from the austenitic region and prompt, small-scale (5%) deformation, or by a combination of accelerated cooling from the austenitic region, 30-40% deformation and high yield. The size of the dislocation cells observed under the electron microscope does not exhibit - within the limits investigated - any direct effect on the cold brittleness temperature. (author)

  6. Green Growth and Low Carbon Society

    DEFF Research Database (Denmark)

    Müller, Anders Riel; Tonami, Aki

    This paper ask the question of what makes Low Carbon and Green Growth and Low Carbon Society policy concepts that have not only gained foothold in their countries of origin, but also globally. Autobiography analysis is employed to discover the stories that these concepts tell about developmental...... challenges in East Asia and beyond. By building on narratives of national progress, overcoming of adversity, and societal harmony, the concepts seek to bypass the gridlock between economic growth and planetary degradation by developing new metanarratives. The paper also analyze on the fact...... that the international coalitions build around the concepts differ significantly, which we argue can be explained, in part, by their differing metanarratives. We argue that, this autobiographical and narrative approach contributes to our understanding of why these concepts have managed to spread internationally....

  7. Sustainable Low Carbon Transport Scenarios for India

    DEFF Research Database (Denmark)

    Shukla, P.R.; Dhar, Subash; Mittal, Shivika

    2014-01-01

    and local air quality that can be accrued by mainstreaming climate change polices into national sustainable development goals and sectoral plans are also estimated. There is no silver bullet that would enable the transition towards low carbon transport. An optimal mix of policies that includes fuel economy...... standards, modal shifts and cleaner energy supply is required to align climate and sustainable development goals in the long-term....... are delineated that would facilitate the sustainable low carbon transformation of India’s transport sector. The long term energy and emission trajectory of India’s transport sector is assessed under alternate scenarios using the integrated assessment modelling framework. Co-benefits like energy security...

  8. INFLUENCE RESEARCH OF COLD PLASTIC DEFORMATION ON DIFFUSION SATURATION PROCESS BY CARBON AND BORON OF THE LOW-CARBON AND BORON-CONTAINING ALLOYS

    Directory of Open Access Journals (Sweden)

    N. Yu. Filonenko

    2010-06-01

    Full Text Available This work is devoted to the study of influence of cold prestrain with degree of deformation within the range 0…40 % on diffusion saturation with boron and carbon for low-carbon and boron steels. It is determined that the plastic prestrain with degree of deformation 20 % at temperature 750 °С for the low-carbon steel promote increasing of boron-cementation layer thickness by 25 % and microhardness of perlite layer by 20 %.

  9. Contribution of archaeological analogs to the estimation of average corrosion rates and long term corrosion mechanisms of low carbon steel in soil; Apport des analogues archeologiques a l'estimation des vitesses moyennes et a l'etude des mecanismes de corrosion a tres long terme des aciers non allies dans les sols

    Energy Technology Data Exchange (ETDEWEB)

    Neff, D

    2003-11-15

    In the context of the French nuclear waste storage, a multi-barriers disposal is envisaged. Wastes could be put in metallic overpacks disposed in a clay soil. As these overpacks could be made of low carbon steel, it is important to understand the corrosion behaviour of this material in soil during period of several centuries. Indeed, it is necessary to consolidate the empirical data by a phenomenological approach. This includes laboratory experiments and modelling of the phenomenon which have to be validated and completed by the study of archaeological artefacts. This was the aim of this PhD-work. To this purpose, an analytical protocol has been elaborated: about forty archaeological artefacts coming from five dated sites (2. to 16. centuries) have been studied on cross section in order to observe on the same sample all the constituents of the system: metallic substrate/corrosion products/environment. The corrosion products are divided into two zones: the Dense Product Layer (DPL) in contact with the metal, and the Transformed Medium (TM) which are the corrosion products formed around soil minerals (quartz grains). The metallic substrate has been studied by the classical methods of materials science (optical and scanning electron microscope, energy and wavelength dispersive spectroscopies). It has been verified that despite their heterogeneity of structure and composition, they are all hypo-eutectoids steels that can contain phosphorous until 0.5 wt%. The corrosion products have been analysed by local structural analytical methods as micro-diffraction under synchrotron radiation ({mu}XRD) and Raman micro-spectroscopy. These two complementary techniques and also the elemental composition analysis conducted to the characterisation of the corrosion forms. On the majority of the samples coming from four sites, the DPL are constituted by goethite including marbles of magnetite/maghemite. On the artefacts from the fifth site, a particular corrosion form has been

  10. Development strategy research of low-carbon tourist city

    Science.gov (United States)

    Dong, Xiaohong

    2017-04-01

    Construction of low-carbon tourist city has become a strategic choice for the development of city construction in our country, becoming the direction and goal of future city development in China. In this paper, the development strategy of low-carbon tourist city is put forward from the aspects of building low-carbon tourism culture, strengthening and perfecting the relevant rules and regulations, establishing and perfecting the decision-making management mechanism of low-carbon tourist city construction, establishing accurate, timely, efficient and comprehensive ecological environment monitoring and supervision network, building economical resource utilization system, strengthening science and technology supporting of low-carbon city construction, establishing low-carbon tourism scenic spot, low-carbon community or low-carbon demonstration area, etc.

  11. Assessing the readiness of contractors in implementing low carbon ...

    African Journals Online (AJOL)

    For the implementation of low carbon construction in our construction industry, the contractors need to be ready and have knowledge to adopt low carbon construction ... A checklist was established by summarizing the highest low carbon activities from each category which were sustainable site planning and management, ...

  12. An economic assessment of low carbon vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Summerton, P. [Cambridge Econometrics CE, Cambridge (United Kingdom); Harrison, P. [European Climate Foundation ECF, Brussels (Belgium)] (eds.)

    2013-03-15

    The study aimed to analyse the economic impacts of decarbonizing light duty vehicles. As part of the study, the impacts of the European Commissions proposed 2020 CO2 regulation for cars and vans have been assessed. The analysis showed that a shift to low-carbon vehicles would increase spending on vehicle technology, therefore generating positive direct employment impacts, but potentially adding 1,000-1,100 euro to the capital cost of the average new car in 2020. However, these additional technology costs would be offset by fuel savings of around 400 euro per year, indicating an effective break-even point for drivers of approximately three years. At the EU level, the cost of running and maintaining the European car fleet would become 33-35 billion euro lower each year than in a 'do nothing scenario' by 2030, leading to positive economic impacts including indirect employment gains. Data on the cost of low carbon vehicle technologies has largely been sourced from the auto industry itself, with the study supported by a core working group including Nissan, GE, the European Association of Automotive Suppliers (CLEPA), and the European Storage Battery Manufacturers Association (Eurobat). Fuel price projections for the study were based on the IEA's World Energy Outlook, while technical modelling was carried out using the transport policy scoping tool SULTAN (developed by Ricardo-AEA for the European Commission) and the Road Vehicle Cost and Efficiency Calculation Framework, also developed by Ricardo-AEA. Macro-economic modelling was done using the E3ME model, which has previously been used for several European Commission and EU government impact assessments. This report focuses on efficient use of fossil fuels in internal combustion- and hybrid electric vehicles. It will be followed by a second report, which will focus on further reducing the use of fossil fuels by also substituting them with domestically produced energy carriers, such as electricity and

  13. Investigating Low-Carbon City: Empirical Study of Shanghai

    Directory of Open Access Journals (Sweden)

    Xuan Yang

    2018-04-01

    Full Text Available A low-carbon economy is an inevitable choice for achieving economic and ecological sustainable development. It is of significant importance to analyze a city’s low-carbon economy development level scientifically and reasonably. In order to achieve this goal, we propose an urban low-carbon economic development level evaluation model based on the matter-element extension method. First, we select some indicators from the existing indicator system based on past research and experience. Then, a matter-element model is established on the basis of weight to evaluate the level of a city’s low-carbon, the critical value of each index is determined through the classical domain and the section domain, calculating the correlation degree of a single index and a comprehensive index. Finally, we analyze the low-carbon economy development status and future development trends according to the analysis results. In this study, we select Shanghai as an empirical study—the results show that Shanghai is a city with a low-carbon level and there is a trend of further improvement in Shanghai’s low-carbon economy. But its low carbon construction and low carbon technology investment are relatively low. In summary, this method can provide another angle for evaluating a city’s low-carbon economy.

  14. Logistics in a low carbon concept: Connotation and realization way

    Science.gov (United States)

    Zheng, Chaocheng; Qiu, Xiaoying; Mao, Jiarong

    2017-01-01

    Low-carbon logistics has become a trend for the logistics industry-as a high-energy consumption industry, continuation of its previous operating mode has been significantly behind the times. So logistics industry must release lower carbon emissions. This paper sort out the literature home and abroad from three aspects, that is, the definition of low-carbon logistics, low-carbon logistics implementation mechanisms or measures, and low carbon design quantitative models. The research shows: low-carbon logistics needed to implemented both in enterprise' macro and micro level, which means the government should provide relevant policy support and micro enterprises should be actively sought from all sectors of the logistics in energy saving. In practice, low-carbon logistics optimization models are effective tools for enterprises to implement emission reduction.

  15. Low Carbon Development Pathways in Indian Agriculture

    Directory of Open Access Journals (Sweden)

    Wang Sonam Wangyel

    2017-01-01

    Full Text Available Indian agriculture sector is a significant emitter of Green House Gas (GHG, which is projected to increase by 47% between 2011 and 2020. In response to this, India has committed itself to voluntarily reduce its emissions intensity (emissions per unit GDP between 20 to 25 percent below 2005 levels by 2020. This would require rapid and significant scaling up of mitigation efforts including the agriculture sector, which remains a challenge, as mitigation is not a priority in Indian agriculture. The study found out that in-spite of numerous mitigation technologies that are readily available for takeoff, the scale of adoption and deployment is far from sufficient to meet the emission targets set by the Government of India, mainly due to lack of financial incentives, capacity building of farmers, and an enabling policy at different levels. This study identified a suite of feasible interventions for promoting low carbon agriculture such as: low tillage systems as it has negative costs due to savings on tillage and fuel; introduction of superior livestock breeds to reduce numbers (especially unproductive cattle and increase yield; use of livestock wastes to produce energy for cooking and heating through bio-gas technology can not only reduce methane emission but also save electricity costs for the households and; introduction of carbon credits and exploration of domestic carbon markets. An enabling policy environment must be created for these interventions to take off.

  16. Low-carbon infrastructure strategies for cities

    Science.gov (United States)

    Kennedy, C. A.; Ibrahim, N.; Hoornweg, D.

    2014-05-01

    Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhouse gas inventories and underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than ~1,500 heating degree days (below an 18 °C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than ~600 tCO2e GWh-1 whereas transportation strategies will differ between low urban density (~6,000 persons km-2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

  17. Low carbon fuel and chemical production from waste gases

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, S.; Liew, F.M.; Daniell, J.; Koepke, M. [LanzaTech, Ltd., Auckland (New Zealand)

    2012-07-01

    LanzaTech has developed a gas fermentation platform for the production of alter native transport fuels and commodity chemicals from carbon monoxide, hydrogen and carbon dioxide containing gases. LanzaTech technology uses these gases in place of sugars as the carbon and energy source for fermentation thereby allowing a broad spectrum of resources to be considered as an input for product synthesis. At the core of the Lanzatech process is a proprietary microbe capable of using gases as the only carbon and energy input for product synthesis. To harness this capability for the manufacture of a diverse range of commercially valuable products, the company has developed a robust synthetic biology platform to enable a variety of novel molecules to be synthesised via gas fermentation. LanzaTech initially focused on the fermentation of industrial waste gases for fuel ethanol production. The company has been operating pilot plant that uses direct feeds of steel making off gas for ethanol production for over 24 months. This platform technology has been further successfully demonstrated using a broad range of gas inputs including gasified biomass and reformed natural gas. LanzaTech has developed the fermentation, engineering and control systems necessary to efficiently convert gases to valuable products. A precommercial demonstration scale unit processing steel mill waste gases was commissioned in China during the 2{sup nd} quarter of 2012. Subsequent scale-up of this facility is projected for the 2013 and will represent the first world scale non-food based low carbon ethanol project. More recently LanzaTech has developed proprietary microbial catalysts capable of converting carbon dioxide in the presence of hydrogen directly to value added chemicals, where-in CO{sub 2} is the sole source of carbon for product synthesis. Integrating the LanzaTech technology into a number of industrial facilities, such as steel mills, oil refineries and other industries that emit Carbon bearing

  18. ballistic performance of a quenched and tempered steel against

    African Journals Online (AJOL)

    eobe

    was investigated. Low alloy steel ... obliquity obliquity with a projectile velocity with a projectile velocity with a projectile .... quenching on low carbon and alloyed steel [5, 15]. Several studies .... Mars 190, Mars 240, Mars 270, Creusot-Loire,.

  19. Metal supply constraints for a low-carbon economy?

    NARCIS (Netherlands)

    Koning, A. de; Kleijn, R.; Huppes, G.; Sprecher, B.; Engelen, G. van; Tukker, A.

    2018-01-01

    Low-carbon energy systems are more metal-intensive than traditional energy systems. Concerns have been expressed that this may hamper the transition to a low-carbon economy. We estimate the required extraction of Fe, Al, Cu, Ni, Cr, In, Nd, Dy, Li, Zn, and Pb until 2050 under several

  20. Contingency theory, climate change, and low-carbon operations management

    DEFF Research Database (Denmark)

    Furlan Matos Alves, Marcelo Wilson; Lopes de Sousa Jabbour, Ana Beatriz; Kannan, Devika

    2017-01-01

    of sustainability managers on the adoption of low-carbon operations management practices and their related benefits. Design/methodology/approach: To achieve this goal, this research uses NVivo software to gather evidence from interviews conducted with ten high-level managers in sustainability and related areas from...... seven leading companies located in Brazil. Findings: The authors present four primary results: a proposal of an original framework to understand the relationship between contingency theory, changes in organisational structure to embrace low-carbon management, adoption of low-carbon operations practices......-change contingencies at the supply chain level, organisational structure for low-carbon management and low-carbon operations management practices and benefits. This research also highlights evidence from an emerging economy and registers future research propositions....

  1. Low carbon transition and sustainable development path of tourism industry

    Science.gov (United States)

    Zhu, Hongbing; Zhang, Jing; Zhao, Lei; Jin, Shenglang

    2017-05-01

    The low carbon transition is as much a transformative technology shift as it represents a response to global environment challenges. The low carbon paradigm presents a new direction of change for tourism industry. However, the lack of theoretical frameworks on low carbon transformation in tourism industry context provides a significant knowledge gap. This paper firstly investigates the relationships between low carbon and sustainable development, followed by exploring the existing challenges of tourism sustainable development. At last, this paper presents a sustainable development path framework for low carbon transition of tourism industry, which include accelerating deployment of renewable energy, energy-saving green building construction, improving green growth investment, and adopting a sustainable consumption and production system, in order to promote energy and water efficiency, waste management, GHG emissions mitigation and eventually enhance its sustainability.

  2. Interphase and intergranular stress generation in carbon steels

    International Nuclear Information System (INIS)

    Oliver, E.C.; Daymond, M.R.; Withers, P.J.

    2004-01-01

    Neutron diffraction spectra have been acquired during tensile straining of high and low carbon steels, in order to compare the evolution of internal stress in ferritic steel with and without a reinforcing phase. In low carbon steel, the generation of intergranular stresses predominates, while in high carbon steel similar intergranular stresses among ferrite grain families are superposed upon a large redistribution of stress between phases. Comparison is made to calculations using elastoplastic self-consistent and finite element methods

  3. Wood-burning stoves in low-carbon dwellings

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; Afshari, Alireza

    2013-01-01

    The European climate change strategy intends to encourage the erection of low-carbon buildings and the upgrading of existing buildings to low-carbon level. At the same time, it is an EU vision to maximise the use of renewable energy resources. In this strategy, small-scale wood......-burning is an overlooked source for heating. A wood-burning stove is considered low-carbon technology since its fuel is based on local residual biomass. A field study investigating how modern wood-burning stoves operated in modern single-family houses showed that intermittent heat supply occasionally conflicted...... combustion technology and automatics, controlling the interplay between stove and house, can make wood-burning stoves suitable for low-carbon dwellings and meet the remaining heat demand during the coldest period. It was further concluded that new guidelines need to be elaborated about how to install...

  4. Natural Gas Based Electricity Production and Low Carbon Technology Options

    Science.gov (United States)

    Concerns regarding air quality, global climate change, and the national energy security impacts of the intensive use of fossil fuels and their environmental impacts in the power generation sector have raised interest in alternative low carbon electricity generation technology and...

  5. Distributed Leadership in a Low-Carbon City Agenda

    Directory of Open Access Journals (Sweden)

    Azalia Mohamed

    2016-07-01

    Full Text Available This paper uses Spillane’s (2001 theory and Gronn’s (2000 concerted efforts approach to examine distributed leadership in a low-carbon city agenda. The main purpose of the paper is to find empirical evidence of a relationship between distributed leadership and the achievement of the agenda. Eight constructs emerged that informed our understanding of distributed leadership dimensions within the low-carbon city framework: vision, organizational framework, organizational culture, consensus, instructional programs, expertise, team leader leadership, and team member leadership. The evidence shows that there is a positive relationship between distributed leadership and the outcome of the low-carbon city agenda, and that a dispersed pattern in distributing leadership is required to enhance community engagement. The findings also suggest that an organizational culture that facilitates multiple sources of leadership may largely contribute to the effectiveness of distributed leadership practices in realizing the low-carbon city agenda.

  6. Final technical report: Certification of low carbon farming practices

    OpenAIRE

    TUOMISTO HANNA LEENA; ANGILERI Vincenzo; DE CAMILLIS CAMILLO; LOUDJANI Philippe; PELLETIER NATHANIEL; HAASTRUP Palle; NISINI SCACCHIAFICHI Luigi

    2013-01-01

    In 2010, the European Parliament asked the European Commission to carry out a pilot project on the “certification of low-carbon farming practices in the European Union” to promote reductions of GHG emissions from farming. The overall aim of the project was to assess how efforts of European farmers to produce agricultural products with carbon-neutral or low-carbon-footprint farming practices might be incorporated into policy approaches (possibly via certification), so as to promote the reducti...

  7. Influencia de la cantidad de O2 adicionado al CO2 en el gas de protección sobre la microestructura del metal depositado en uniones soldadas de bordes rectos en aceros de bajo contenido de carbono con el proceso GMAW Influence of O2 content, added to CO2 in the shielding gas, on the microstructure of deposited metal in butt welded joint with straight edges, in low carbon steels using GMAW process

    Directory of Open Access Journals (Sweden)

    Eduardo Díaz-Cedré

    2010-12-01

    Full Text Available La presencia de ferrita acicular (FA en la microestructura del cordón de soldadura, dentro de determinado rango de valores, eleva considerablemente la tenacidad de las uniones soldadas. Es por ello, que el presente trabajo trata sobre un estudio que relaciona la cantidad de ferrita acicular en el cordón en función del contenido de oxígeno presente en la mezcla activa CO2+O2, durante la realización de uniones soldadas de bordes rectos en aceros de bajo carbono con el proceso con electrodo fusible y protección gaseosa (GMAW en condiciones invariables de parámetros de proceso (corriente de soldadura, voltaje de arco, velocidad de soldadura, longitud libre y flujo de gas protector. Como resultado del trabajo se estableció la relación gráfica existente entre la ferrita acicular y el contenido de oxígeno en la mezcla.The presence of acicular ferrite (AF in the microstructure of weld bead, in a specified range of values, increase considerably the toughness of welded joints. The present paper, for that reason, study the relationship between the acicular ferrite quantity in the deposited metal and the oxygen present in the active gas mixture of CO2+O2, during the execution of butt welded joints with straight edges, in low carbon steels with consumable electrode and gas protection (GMAW in invariable conditions of process parameters (welding current, arc voltage, welding speed, electrode extension, and gas flow. The graphic relation between the acicular ferrite and the oxygen content was established, as result of the research work.

  8. Nested barriers to low-carbon infrastructure investment

    Science.gov (United States)

    Granoff, Ilmi; Hogarth, J. Ryan; Miller, Alan

    2016-12-01

    Low-carbon, 'green' economic growth is necessary to simultaneously improve human welfare and avoid the worst impacts of climate change and environmental degradation. Infrastructure choices underpin both the growth and the carbon intensity of the economy. This Perspective explores the barriers to investing in low-carbon infrastructure and some of the policy levers available to overcome them. The barriers to decarbonizing infrastructure 'nest' within a set of barriers to infrastructure development more generally that cause spending on infrastructure--low-carbon or not--to fall more than 70% short of optimal levels. Developing countries face additional barriers such as currency and political risks that increase the investment gap. Low-carbon alternatives face further barriers, such as commercialization risk and financial and public institutions designed for different investment needs. While the broader barriers to infrastructure investment are discussed in other streams of literature, they are often disregarded in literature on renewable energy diffusion or climate finance, which tends to focus narrowly on the project costs of low- versus high-carbon options. We discuss how to overcome the barriers specific to low-carbon infrastructure within the context of the broader infrastructure gap.

  9. Hydrogen - the answer to our prayer for low carbon transport?

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Albert; Kershaw, Ian; Vinke, Jan [Ricardo Strategic Consulting GmbH, Muenchen (Germany)

    2008-07-01

    As political, social and economic pressure mounts, the automotive industry needs low carbon solutions - but how do we get there? Despite higher fuel prices and pressure to reduce vehicle CO{sub 2} in many countries, consumers assume limited personal responsibility for reducing carbon emissions from their road transport. The automotive industry is challenged with developing low carbon vehicles without compromise on cost, performance or practicality. The options for reducing CO{sub 2} emissions from road transport range from improved traffic management and driving behaviour, to improved vehicle technologies. Incremental efficiency improvements will be the most cost-effective way of improving powertrains, while economics and availability will continue to limit use of fuel cells, hydrogen and biofuels. We propose an evolutionary route of downsized combustion engines, increasing hybrid electric capability and more biofuel blends, supplemented by lower carbon plug-in electric power for short journeys. The transition to low carbon transport will require policies to encourage consumer demand. (orig.)

  10. Low Carbon Supplier Selection in the Hotel Industry

    Directory of Open Access Journals (Sweden)

    Chia-Wei Hsu

    2014-05-01

    Full Text Available This study presents a model for evaluating the carbon and energy management performance of suppliers by using multiple-criteria decision-making (MCDM. By conducting a literature review and gathering expert opinions, 10 criteria on carbon and energy performance were identified to evaluate low carbon suppliers using the Fuzzy Delphi Method (FDM. Subsequently, the decision-making trial and evaluation laboratory (DEMATEL method was used to determine the importance of evaluation criteria in selecting suppliers and the causal relationships between them. The DEMATEL-based analytic network process (DANP and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR were adopted to evaluate the weights and performances of suppliers and to obtain a solution under each evaluation criterion. An illustrative example of a hotel company was presented to demonstrate how to select a low carbon supplier according to carbon and energy management. The proposed hybrid model can help firms become effective in facilitating low carbon supply chains in hotels.

  11. Global low-carbon transition and China's response strategies

    Directory of Open Access Journals (Sweden)

    Jian-Kun He

    2016-12-01

    Full Text Available The Paris Agreement establishes a new mechanism for post-2020 global climate governance, and sets long-term goals for global response to climate change, which will accelerate worldwide low-carbon transformation of economic development pattern, promote the revolutionary reform of energy system, boost a fundamental change in the mode of social production and consumption, and further the civilization of human society from industrial civilization to eco-civilization. The urgency of global low-carbon transition will reshape the competition situation of world's economy, trade and technology. Taking the construction of eco-civilization as a guide, China explores green and low-carbon development paths, establishes ambitious intended nationally determined contribution (INDC targets and action plans, advances energy production and consumption revolution, and speeds up the transformation of economic development pattern. These strategies and actions not only confirm to the trend of the world low-carbon transition, but also meet the intrinsic requirements for easing the domestic resources and environment constraints and realizing sustainable development. They are multi-win-win strategies for promotion of economic development and environmental protection and mitigation of carbon emissions. China should take the global long-term emission reduction targets as a guide, and formulate medium and long-term low-carbon development strategy, build the core competitiveness of low-carbon advanced technology and development pattern, and take an in-depth part in global governance so as to reflect the responsibility of China as a great power in constructing a community of common destiny for all mankind and addressing global ecological crisis.

  12. The Deployment of Low Carbon Technologies in Energy Intensive Industries: A Macroeconomic Analysis for Europe, China and India

    Directory of Open Access Journals (Sweden)

    Stefan Nabernegg

    2017-03-01

    Full Text Available Industrial processes currently contribute 40% to global CO2 emissions and therefore substantial increases in industrial energy efficiency are required for reaching the 2 °C target. We assess the macroeconomic effects of deploying low carbon technologies in six energy intensive industrial sectors (Petroleum, Iron and Steel, Non-metallic Minerals, Paper and Pulp, Chemicals, and Electricity in Europe, China and India in 2030. By combining the GAINS technology model with a macroeconomic computable general equilibrium model, we find that output in energy intensive industries declines in Europe by 6% in total, while output increases in China by 11% and in India by 13%. The opposite output effects emerge because low carbon technologies lead to cost savings in China and India but not in Europe. Consequently, the competitiveness of energy intensive industries is improved in China and India relative to Europe, leading to higher exports to Europe. In all regions, the decarbonization of electricity plays the dominant role for mitigation. We find a rebound effect in China and India, in the size of 42% and 34% CO2 reduction, respectively, but not in Europe. Our results indicate that the range of considered low-carbon technology options is not competitive in the European industrial sectors. To foster breakthrough low carbon technologies and maintain industrial competitiveness, targeted technology policy is therefore needed to supplement carbon pricing.

  13. Possibilities and Challenges designing low-carbon-energy technologies

    DEFF Research Database (Denmark)

    Bjarklev, Araceli

    Though there is broad consensus that one of the solutions to the current environmental challenge will be based on the use of low-carbon technologies, and even though there is a big potential to turn to a more sustainable design and innovation, there are several elements that need to be taken...... as a study object and discusses the question: What are the main possibilities and challenges when designing low-carbon illumination technologies? To answer this question, we use a systemic approach including environmental, economic, energy and political issues using relevant concepts from the Ecological...

  14. Investigation of Corrosion and Cathodic Protection in Reinforced Concrete. II : Properties of Steel Surface Layers

    NARCIS (Netherlands)

    Koleva, D.A.; De Wit, J.H.W.; Van Breugel, K.; Lodhi, Z.F.; Ye, G.

    2007-01-01

    The present study explores the formation of corrosion products on the steel surface (using as-received low carbon construction steel) in reinforced concrete in conditions of corrosion and subsequent transformation of these layers in conditions of cathodic protection (CP).

  15. Developing low carbon policies for road transport in Poland

    NARCIS (Netherlands)

    Kok, R.; Rahman, S.A.

    2010-01-01

    This paper presents the results of work done for the World Bank to develop low carbon policies for road transport in Poland. Here, we outline the development of Green House Gas (GHG) emissions, develop a Business As Usual (BAU) scenario based on social-economic-, infrastructure-, car market, vehicle

  16. Renewable energy and low carbon economy transition in India

    DEFF Research Database (Denmark)

    Shukla, P.R.; Dhar, Subash; Fujino, Junichi

    2010-01-01

    that aligns India’s emissions to an optimal 450 ppmv CO2-eq. stabilization global response. The second emissions pathway assumes an underlying sustainable development pattern. A low carbon future will be good for renewable energy under both the development pathways, though the share of renewable energy...

  17. Fusion power in a future low carbon global electricity system

    DEFF Research Database (Denmark)

    Cabal, H.; Lechón, Y.; Bustreo, C.

    2017-01-01

    Fusion is one of the technologies that may contribute to a future, low carbon, global energy supply system. In this article we investigate the role that it may play under different scenarios. The global energy model ETM (originally EFDA TIMES Model) has been used to analyse the participation...

  18. Funding pathways to a low-carbon transition

    Science.gov (United States)

    Foulds, Chris; Christensen, Toke Haunstrup

    2016-07-01

    The framing of funding programmes can sustain existing ways of conceptualizing particular problems, as well as create new ones. Yet, without more prominent roles for social sciences and humanities, the techno-economic conceptualization of energy consumers could hinder long-term low-carbon aspirations.

  19. Low Carbon and Climate Resilient Investments: Is South Africa ...

    African Journals Online (AJOL)

    . The aim of this paper is to review South Africa's response to climate change, with a special focus on investments in low carbon and climate resilient action. It highlights the successes to date and the challenges that still have to be addressed.

  20. Construction and applied research of low-carbon building evaluation index system

    Science.gov (United States)

    Liu, Zhongwen; Dong, Xiaohong; Gao, Pengzhao

    2017-04-01

    Energy conservation in building is a key link on alleviating energy-deficient contradiction, improving the quality of human life environment, and realizing sustainable development in our country. In this paper, we construct low-carbon building evaluation index system and evaluation method from five aspects—low-carbon structure, low-carbon materials, low-carbon energy, low-carbon technology and low-carbon management. Finally, taking “Solar Valley” in Dezhou as an example, we make the evaluation to its situation of low-carbon building.

  1. Overview of Low Carbon Logistics Development in China and Foreign Countries

    Science.gov (United States)

    Cheng, Dongxiang; Zhang, Xiang

    2017-12-01

    High energy consumption is a major feature of the logistics industry. Under the current low-carbon development requirements, the low carbon development of logistics is bound to be a new direction, and more scholars will turn their attention to low-carbon logistics. This paper presents a detailed introduction to low-carbon logistics from four aspects: the definition of low-carbon logistics, the influencing factors and Countermeasures of development, and the evaluation of carbon emission efficiency.

  2. Our struggle for climate - a low carbon world with growth is possible

    International Nuclear Information System (INIS)

    Chalendar, Pierre-Andre de

    2015-01-01

    In order to avoid an irreversible climate catastrophe, and as the will and commitments of States are not enough, the mobilisation of companies and enterprises is essential. This book aims to show that enterprises, which have been for long considered as responsible of greenhouse gas emissions, are now at the forefront of the struggle against climate change. The author describes the various challenges faced by French companies regarding climate and the environment. He thinks that the world will always need more energy, more steel, more aluminium, more building materials, more cars, more chemistry, more machines, more tubes and cables. The solution is then a technological one to transform industrial activities for a low carbon or zero carbon and growing economy

  3. Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

    Institute of Scientific and Technical Information of China (English)

    Yu; Han; Li; Caige

    2016-01-01

    Targeted at the dynamic demands in the rapid urban construction, the planning technology strategy of the Shenzhen International Low Carbon City studies the fl exible index model based on carbon emission evaluation, and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment. Meanwhile, it also evaluates the application of low carbon technology and gives feedback in time, so as to constantly optimize and complete the low carbon city planning. In detail, it involves industrial planning, ecological restoration, transport planning, energy resource planning, architectural design, etc., for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages. The quick-response and fl exible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development, thus realizing the sustainable leap-forward development and providing reference for other similar regions.

  4. Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

    Institute of Scientific and Technical Information of China (English)

    Yu Han; Li Caige

    2016-01-01

    Targeted at the dynamic demands in the rapid urban construction,the planning technology strategy of the Shenzhen International Low Carbon City studies the flexible index model based on carbon emission evaluation,and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment.Meanwhile,it also evaluates the application of low carbon technology and gives feedback in time,so as to constantly optimize and complete the low carbon city planning.In detail,it involves industrial planning,ecological restoration,transport planning,energy resource planning,architectural design,etc.,for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages.The quick-response and flexible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development,thus realizing the sustainable leap-forward development and providing reference for other similar regions.

  5. Have You Switched to a Low-Carbon Diet? The Ultimate Value of Low-Carbon Consumerism

    Directory of Open Access Journals (Sweden)

    Yu-Ling Lin

    2014-04-01

    Full Text Available Since the 1990s many governments around the world have been encouraging their people to participate in green or low carbon living. With the background of rising consumer awareness in environmental protection, green consumption, and green marketing are receiving growing attention from consumers and enterprises. Therefore, the purpose of this paper is to identify the goals and values of 60 Taiwanese consumers in a low-carbon diet. This study uses the theory of Mean-end chain as basis, applying the “Soft-laddering” of “Laddering” to understand the perceived value of low carbon food in depth interviews. The results revealed that the attributes of users care for green living in the, order of, Less meat more vegetables, Seasonal food, Local food, Food with minimal artificial processing, Energy-saving preparation and Carbon footprint. After classifying by content analysis, we draw the Hierarchical value map (HVM to explore that consumer’s pursuit of the final value and benefits by adopting a low-carbon diet relate to healthy living.

  6. Boron Steel: An Alternative for Costlier Nickel and Molybdenum Alloyed Steel for Transmission Gears

    Directory of Open Access Journals (Sweden)

    A. Verma

    2010-06-01

    Full Text Available Case Carburized (CC low carbon steels containing Ni, Cr and Mo alloying elements are widely used for transmission gears in automobile, as it possesses desired mechanical properties. In order to cut cost and save scarce materials like Ni and Mo for strategic applications, steel alloyed with Boron has been developed, which gives properties comparable to Ni-Cr-Mo alloyed steel. In the process of steel development, care was taken to ensure precipitation of boron which results in precipitation hardening. The characterization of the developed boron steel had exhibited properties comparable to Ni-Cr-Mo alloyed steel and superior to conventional boron steel.

  7. GRAPHITIZED STEELS IN MACHINE-BUILDING

    Directory of Open Access Journals (Sweden)

    I. V. Akimov

    2010-01-01

    Full Text Available It is shown that graphitized steels in some cases due to its intermediate disposition by structure and characteristics among low-carbon steels and cast irons, can provide the necessary combination of characteristics of construction material and consequently to increase safety and durability of details of metallurgical and machinebuilding industry machines.

  8. Development of Advanced High Strength Steel for Improved Vehicle Safety, Fuel Efficiency and CO2 Emission

    Science.gov (United States)

    Kumar, Satendra; Singhai, Mrigandra; Desai, Rahul; Sam, Srimanta; Patra, Pradip Kumar

    2016-10-01

    Global warming and green house gas emissions are the major issues worldwide and their impacts are clearly visible as a record high temperatures, rising sea, and severe `flooding and droughts'. Motor vehicles considered as a major contributor on global warming due to its green house gas emissions. Hence, the automobile industries are under tremendous pressure from government and society to reduce green house gas emission to maximum possible extent. In present work, Dual Phase steel with boron as microalloying is manufactured using thermo-mechanical treatment during hot rolling. Dual phase steel with boron microalloying improved strength by near about 200 MPa than dual phase steel without boron. The boron added dual phase steel can be used for manufacturing stronger and a lighter vehicle which is expected to perform positively on green house gas emissions. The corrosion resistance behavior is also improved with boron addition which would further increase the life cycle of the vehicle even under corrosive atmosphere.

  9. Radiation damage of the construction materials, Phase II, Microstructure and grain size effects on irradiation hardening of low carbon steel for reactor tanks; Radijaciono ostecenje konstrukcionih materijala, II faza, Uticaj velicine zrna i mikrostrukture na radijaciono otvrdnjavanje niskougljenicnih celika za reaktorske sudove

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, Dj; Milasin, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1964-05-15

    Influence of grain size on radiation damage of different steel types was investigated intensely during past few years. But the obtained data did not enable complete answer. The objective of here described experiments was to obtain new data about the influence of grain size on radiation hardening of the steel for reactor vessel fabrication. The steel was exposed to integral fast neutron flux bigger than 10{sup 19} n/cm{sup 2} and irradiation temperature less than 100 deg C. As a part of VISA-2/1 project these investigations we redone in cooperation with the CEN Saclay. Simultaneously, experimental procedures applied for obtaining samples with different grain sizes produced steels with different macrostructure. For that reason possible influence of microstructure should ne taken into account. In fact, it was found that the performance of samples depended more on microstructure than on the grain size. The most important results obtain from this experiments indicate the following: (1) samples with different grain size having ferrite-perlite structure showed the same tensile strength; (2) samples with cementite on the grain boundaries showed more intensive hardening after irradiation; (3) samples exposed to {gamma} radiation for obtaining bigger grains showed decreased hardening than samples deformed under room temperature and exposed to {alpha} radiation. Experiments were performed under 150 deg C. samples with ferrite-perlite microstructure showed further smaller increase of tensile limit and hardening. Uticaj velicine zrna na radijaciono otvrdnjavanje razlicitih tipova celika intenzivno je proucavan u toku poslednjih nekoliko godina. Medjutim, dobijeni podaci nisu omogucili da se u potpunosti odgovori na pitanje. Opisani eksperimenti imali su za cilj da pruze nove podatke o uticaju velicine zrna na radijaciono otvrdnjavanje date vrste celika za reaktorski sud, pri integralnom fluksu brzih neutrona > 10{sup 19} n/cm{sup 2} i temperaturi ozracivanja < 100 deg C. Kao

  10. Low carbon national strategy. A macro-economical assessment

    International Nuclear Information System (INIS)

    Baiz, Adam; Monnoyer-Smith, Laurence; Callonnec, Gael

    2016-11-01

    This publication briefly reports the use of the Three-ME model (Multi-sector Macroeconomic Model for the Evaluation of Environmental and Energy) to assess the combined effect of the several instruments mobilised for the transition towards a low carbon economy within the French National Low Carbon Strategy (SNBC). It first presents the Three-ME model which has been developed since 2008 by the OFCE and the Ademe, is a neo-Keynesian and hybrid model, and which comprises 14.000 equations and 70.000 parameters dealing with prices, interest rates, investments, salaries, foreign trade, State policy, a production function, and a consumption function. Some characteristics of the SNBC scenario are indicated, as well as those of a reference trend-based scenario. Obtained results are then briefly commented in terms of positive ecological and economic impacts of a carbon tax and of sector-based measures defined within the SNBC

  11. Health benefits, ecological threats of low-carbon electricity

    Science.gov (United States)

    Gibon, Thomas; Hertwich, Edgar G.; Arvesen, Anders; Singh, Bhawna; Verones, Francesca

    2017-03-01

    Stabilizing global temperature will require a shift to renewable or nuclear power from fossil power and the large-scale deployment of CO2 capture and storage (CCS) for remaining fossil fuel use. Non-climate co-benefits of low-carbon energy technologies, especially reduced mortalities from air pollution and decreased ecosystem damage, have been important arguments for policies to reduce CO2 emissions. Taking into account a wide range of environmental mechanisms and the complex interactions of the supply chains of different technologies, we conducted the first life cycle assessment of potential human health and ecological impacts of a global low-carbon electricity scenario. Our assessment indicates strong human health benefits of low-carbon electricity. For ecosystem quality, there is a significant trade-off between reduced pollution and climate impacts and potentially significant ecological impacts from land use associated with increased biopower utilization. Other renewables, nuclear power and CCS show clear ecological benefits, so that the climate mitigation scenario with a relatively low share of biopower has lower ecosystem impacts than the baseline scenario. Energy policy can maximize co-benefits by supporting other renewable and nuclear power and developing biomass supply from sources with low biodiversity impact.

  12. The development of low-carbon vehicles in China

    International Nuclear Information System (INIS)

    Yao Mingfa; Liu Haifeng; Feng Xuan

    2011-01-01

    Reducing CO 2 emissions from vehicles in China is crucial and will significantly alleviate the environmental burden of the Earth. Some promising technologies that make possible low-carbon vehicles are reviewed in this work, including electric vehicles, fuel cell vehicles, hybrid vehicles, biofuels vehicles, other alternative fuel vehicles, and conventional internal combustion engine vehicles with improvement. In the short term, expanding the use of mature technologies in conventional gasoline or diesel vehicles is the most realistic, effective, and timely solution for China to meeting the urgent challenges of energy saving and greenhouse gas reduction; while in the long run biofuel is a promising candidate due to their renewability and carbon neutrality. The blueprint of low-carbon vehicles for China depends on three aspects: breakthroughs in technology, awareness of public, and government guidance. - Highlights: → Reducing CO 2 emissions and saving energy from vehicles in China is crucial. → Low-carbon depends on technology breakthrough, public awareness, and government guidance. → Use of mature technologies in ICEVs is the most realistic solution for China. → Biofuels are the key to realize neutral carbon emission in the long run.

  13. Low Carbon Footprint mortar from Pozzolanic Waste Material

    Science.gov (United States)

    Mehmannavaz, Taha; Mehman navaz, Hossein Ali; Moayed Zefreh, Fereshteh; Aboata, Zahra

    2017-04-01

    Nowadays, Portland cement clinker leads to emission of CO2 into the atmosphere and therefore causes greenhouse effect. Incorporating of Palm Oil Fuel Ash (POFA) and Pulverized Fuel Ash (PFA) as partial cement replacement materials into mix of low carbon mortar decreases the amount of cement use and reduces high dependence on cements compared to ordinary mortar. The result of this research supported use of the new concept in preparing low carbon mortar for industrial constructions. Strength of low carbon mortar with POFA and PFA replacement in cement was affected and changed by replacing percent finesse, physical and chemical properties and pozzolanic activity of these wastes. Waste material replacement instead of Ordinary Portland Cement (OPC) was used in this study. This in turn was useful for promoting better quality of construction and innovative systems in construction industry, especially in Malaysia. This study was surely a step forward to achieving quality products which were affordable, durable and environmentally friendly. Disposing ash contributes to shortage of landfill space in Malaysia. Besides, hazard of ash might be another serious issue for human health. The ash disposal area also might create a new problem, which is the area's sedimentation and erosion.

  14. Scenarios for transition towards a low-carbon world in 2050: What's at stake for heavy industries?

    International Nuclear Information System (INIS)

    2008-11-01

    Launched in 2004, the study Scenarios for transition towards a low-carbon world in 2050: What's at stake for heavy industries explores how major industrial sectors will be impacted by a carbon constraint stabilizing atmospheric CO 2 concentration at 450 ppm. By means of an innovative hybrid modelling platform and ongoing dialogue between researchers and industrialists, the study produces conclusions concerning both general climate policy as well as the economic response of industrial sectors - specifically of the steel, aluminium, cement, and sheet glass sectors, as well as of the energy sector. (authors)

  15. Going Clean - The Economics of China's Low-carbon Development

    Energy Technology Data Exchange (ETDEWEB)

    Hallding, Karl; Thai, Helen; Han, Guoyi; Olsson, Marie; Kartha, Sivan [Stockholm Environment Inst. (Sweden); Eklund, Klas [SEB, Stockholm (Sweden); Ming, SU [Peking Univ. (China); Jing, Cao [Tsinghua Univ. (China); Luderer, [Potsdam Inst. for Climate Impact (Germany)

    2009-11-15

    This report shows that China can achieve the transition to a low-carbon economy. China can make these emissions reductions within the tight constraints of a global 2 deg C target while still meeting development and economic growth goals over the next four decades. There are strong mitigation potentials in the building, industry, transport and electricity generation sectors. China would benefit from early mitigation, but immediate action is critical for the world to have a reasonable chance of keeping warming below the 2 deg C target. Such a transition would also be an essential part of China's modernisation. A low-carbon transition presents opportunities for China to improve its energy security and move its economy up the value chain in the production of international goods and services. A low-carbon China is a country with a larger service sector, more advanced labour skills and less environmental degradation. During this transition, new, green job opportunities will emerge, and support an overall shift to a low-carbon economy. Active labour market and social policies, vocational training and upgrading of skills are imperative to facilitate this modernisation and reduce the impact of jobs lost in resource-intensive industries. With today's low price on carbon emissions, the incentives for a low-carbon transition are not sufficiently strong. Consumption and production patterns must be steered in a more resource-sustainable direction. A first step is to phase out subsidies on fossil fuels. Another is to place a price on carbon, either through a carbon tax or a cap-and-trade system, which would create incentives for companies and individuals to produce and consume less carbon-intensive goods and services, and to undertake abatement opportunities to reduce their overall carbon footprint. Advancing technology and innovation need to be fundamental, shared policy objectives in this transition. Early investment reduces costs and paves the way for large-scale abatement

  16. An exploration of residents’ low-carbon awareness and behavior in Tianjin, China

    International Nuclear Information System (INIS)

    Bai, Yin; Liu, Yong

    2013-01-01

    This paper explores the empirical evidence of the link between residents’ low-carbon awareness and their behaviors in China. A questionnaire measuring seven dimensions (including low-carbon knowledge, low-carbon value, low-carbon attitude, private low-carbon behavior, public low-carbon behavior, barrier and motivator) was distributed to the residents of Tianjin, yielding 354 valid responses. The results indicated that there was a low-carbon awareness–behavior gap. In particular, the level of behavior was higher than awareness because the motivators were stronger than the barriers. Second, in exploring the affects of motivators versus barriers on the residents’ private and public low-carbon behaviors, we found that motivators promoted both private and public low-carbon behaviors while barriers significantly inhibited public low-carbon behaviors. Third, Chinese social and cultural factors are discussed to inform our exploration of the mechanisms forming the residents’ awareness–behavior gap. - Highlights: • There was a low-carbon awareness–behavior gap. • The level of behavior was higher than awareness. • The motivators promoted both private and public low-carbon behaviors. • The barriers significantly inhibited public low-carbon behaviors

  17. A Fuzzy-Grey Multicriteria Decision Making Approach for Green Supplier Selection in Low-Carbon Supply Chain

    Directory of Open Access Journals (Sweden)

    Qinghua Pang

    2017-01-01

    Full Text Available Due to the increasing awareness of global warming and environmental protection, many practitioners and researchers have paid much attention to the low-carbon supply chain management in recent years. Green supplier selection is one of the most critical activities in the low-carbon supply chain management, so it is important to establish the comprehensive criteria and develop a method for green supplier selection in low-carbon supply chain. The paper proposes a fuzz-grey multicriteria decision making approach to deal with these problems. First, the paper establishes 4 main criteria and 22 subcriteria for green supplier selection. Then, a method integrating fuzzy set theory and grey relational analysis is proposed. It uses the membership function of normal distribution to compare each supplier and uses grey relation analysis to calculate the weight of each criterion and improves fuzzy comprehensive evaluation. The proposed method can make the localization of individual green supplier more objectively and more accurately in the same trade. Finally, a case study in the steel industry is presented to demonstrate the effectiveness of the proposed approach.

  18. Precipitation Strengthening by Induction Treatment in High Strength Low Carbon Microalloyed Hot-Rolled Plates

    Science.gov (United States)

    Larzabal, G.; Isasti, N.; Rodriguez-Ibabe, J. M.; Uranga, P.

    2018-03-01

    The use of microalloyed steels in the production of thick plates is expanding due to the possibility of achieving attractive combinations of strength and toughness. As market requirements for high strength plates are increasing and new applications require reduced weight and innovative designs, novel approaches to attaining cost-effective grades are being developed. The mechanism of precipitation strengthening has been widely used in thin strip products, since the optimization of the coiling strategy offers interesting combinations in terms of final properties and microalloying additions. Precipitation strengthening in thick plates, however, is less widespread due to the limitation of interphase precipitation during continuous cooling after hot rolling. With the main objective of exploring the limits of this strengthening mechanism, laboratory thermomechanical simulations that reproduced plate hot rolling mill conditions were performed using low carbon steels microalloyed with Nb, NbMo, and TiMo additions. After continuous cooling to room temperature, a set of heat treatments using fast heating rates were applied simulating the conditions of induction heat treatments. An important increase of both yield and tensile strengths was measured after induction treatment without any important impairment in toughness properties. A significant precipitation hardening is observed in Mo-containing grades under specific heat treatment parameters.

  19. Fostering low-carbon growth initiatives in Thailand

    International Nuclear Information System (INIS)

    Criqui, Patrick; Peytral, Pierre-Olivier; Simon, Jean-Christophe; Valadier, Cecile

    2012-02-01

    The current debate on climate strategy and low-carbon economy has increased in complexity: negotiations on the international scene are lacking clear prospects, while the world economic context, international governance and growth prospects remain highly uncertain. In spite of these difficulties, contributors to this study consider that there is a major opportunity for Thailand to address climate change mitigation as part of its overall development strategy, within the 11. NESDP (2012-2016). We strongly believe that Thailand could maximize the benefits of proactive strategies to address climate change adaptation and mitigation by strengthening and expanding already substantial efforts and existing policies. It is also considered that climate policy can be seen as a relevant component of both sustainable development strategy and promotion of national competitiveness. Several key points can be stressed here regarding climate change mitigation strategies and policies in Thailand: - A set of existing policies has already been implemented, mostly focused on the energy sector. - Substantial experience of government departments and agencies has built up over the past two decades in identifying options, coordinating exchanges of views and implementing targeted policies. - A national scientific potential is already established, with a diversity of expertise and a capacity for nationwide field work. Coordinated initiatives of the private sector have been diverse and substantial in major sectors of activity. - Growing awareness in civil society, which is nevertheless combined with entrenched attitudes, resistance to change in everyday life, as in most other countries, whether developed or developing. Recent policy debate, backed by a strong corpus of scientific analysis, considers that a national strategy for Green Economy, or Low-Carbon Economy, should comprise both cross-sector policies and targeted sector-oriented policies. A preliminary analysis of the existing policy mix

  20. Transition pathways for a UK low carbon electricity future

    International Nuclear Information System (INIS)

    Foxon, Timothy J.

    2013-01-01

    Achieving long-term targets for greenhouse gas emissions reductions, such as the UK's legally-binding target of reducing its emissions by 80% by 2050, will require a transition in systems for meeting and shaping energy service demands, involving radical substitution to low-carbon supply technologies and improvements in end-use energy efficiency. This paper describes the development and high-level analysis of a set of transition pathways to a UK low carbon electricity system, explaining key features of the core pathways developed and the distinctiveness and value of the approach. The pathways use an ‘action space’ concept to explore the dynamic interactions between choices made by actors, which are influenced by the competing governance ‘framings’ or ‘logics’ that different actors pursue. The paper sets out three core transition pathways – Market Rules, Central Co-ordination and Thousand Flowers, in which market, government and civil society logics respectively dominate. It summarises the key technological and institutional changes in these pathways, and the roles of actors in bringing these about. This leads to an identification of the key risks to the realisation of each of the pathways, and of the challenges for individuals, businesses, social movements and policy-makers in taking action to bring them about and sustain them. - Highlights: ► Development of a set of transition pathways to a UK low carbon electricity system. ► Action space to explore the dynamic interactions between choices made by actors. ► Three core pathways in which market, government and civil society logics dominate. ► Key technological and institutional changes, and the roles of actors in pathways. ► Challenges for different actors in realising pathways.

  1. The role of utilities in developing low carbon, electric megacities

    International Nuclear Information System (INIS)

    Kennedy, Chris; Stewart, Iain D.; Facchini, Angelo; Mele, Renata

    2017-01-01

    Development of electric cities, with low carbon power supply, is a key strategy for reducing global CO2 emissions. We analyze the role of electric utilities as important actors to catalyze the transition to electric cites, drawing upon data for the world's 27 megacities. Progress towards the ideal electric city is most advanced for Paris, Rio de Janeiro, Sao Paulo and Buenos Aires for low carbon electricity, while Indian megacities have relatively high use of carbon-intensive electricity as a percentage of total energy use. There is wide variety in the structure of markets for electricity provision in megacities, with a dominant, public utility being the most common model. We review literature on electricity sector business models and broadly propose future models dependent on the predominance of locally dispersed generation and the nature of the ownership of the electric grid within the city. Where a high proportion of electricity can be provided by locally distributed supply within a city, the role of utilities could predominantly become that of enabler of exchange with the grid, but new pricing structures are required. A further challenge for utilities in enabling the electric city is to provide a higher level of resilience to events that disrupt power supply. - Highlights: • Amongst 27 megacities, Paris, Rio, Sao Paulo and Buenos Aires are most progressed low carbon electric cities. • Indian megacities have relatively high use of electricity as a percentage of total energy use. • Wide variety in electricity market structure in megacities; dominant, public utility the most common model. • Utilities could become enablers of exchange with the grid, but new pricing models required.

  2. Can low-carbon societies deliver on energy security?

    International Nuclear Information System (INIS)

    Jewell, Jessica

    2015-01-01

    The impact of low-carbon policies on energy security depends on both the timing and intensity of these policies, and the definition of energy security: security of what?; security for whom?; and security from which threats? The priorities of the EU’s 2030 climate/energy package and energy security show little if any alignment. Global climate stabilization policies benefit the energy security of India, China, and the EU, but may have negative impacts on export revenues of the U.S. and other energy exporters.

  3. The Development of Low-Carbon Strategy in Croatia

    International Nuclear Information System (INIS)

    Grgasovic, V.

    2013-01-01

    United Nations Framework Convention on Climate Change and the Kyoto Protocol have initiated an awareness of the necessity to reduce greenhouse gas emissions and have provided guidelines of the energy in the world, especially within the European Union. EU sets its action within the negotiations on a new global agreement in the field of climate change, for the period after the 2020. Croatia, also, has to follow these guidelines. Therefore, Croatia conducts activities to develop low-carbon development strategy and to establish the legal and institutional framework for the successful implementation of measures to reduce greenhouse gas emissions.(author)

  4. Funding pathways to a low-carbon transition

    DEFF Research Database (Denmark)

    Foulds, Chris; Christensen, Toke Haunstrup

    2016-01-01

    The framing of funding programmes can sustain existing ways of conceptualizing particular problems, as well as create new ones. Yet, without more prominent roles for social sciences and humanities, the techno-economic conceptualization of energy consumers could hinder long-term low-carbon aspirat......The framing of funding programmes can sustain existing ways of conceptualizing particular problems, as well as create new ones. Yet, without more prominent roles for social sciences and humanities, the techno-economic conceptualization of energy consumers could hinder long-term low...

  5. Evaluation of creep-fatigue life prediction methods for low-carbon/nitrogen-added SUS316

    International Nuclear Information System (INIS)

    Takahashi, Yukio

    1998-01-01

    Low-carbon/medium nitrogen 316 stainless steel called 316FR is a principal candidate for the high-temperature structural materials of a demonstration fast reactor plant. Because creep-fatigue damage is a dominant failure mechanism of the high-temperature materials subjected to thermal cycles, it is important to establish a reliable creep-fatigue life prediction method for this steel. Long-term creep tests and strain-controlled creep-fatigue tests have been conducted at various conditions for two different heats of the steel. In the constant load creep tests, both materials showed similar creep rupture strength but different ductility. The material with lower ductility exhibited shorter life under creep-fatigue loading conditions and correlation of creep-fatigue life with rupture ductility, rather than rupture strength, was made clear. Two kinds of creep-fatigue life prediction methods, i.e. time fraction rule and ductility exhaustion method were applied to predict the creep-fatigue life. Accurate description of stress relaxation behavior was achieved by an addition of 'viscous' strain to conventional creep strain and only the latter of which was assumed to contribute to creep damage in the application of ductility exhaustion method. The current version of the ductility exhaustion method was found to have very good accuracy in creep-fatigue life prediction, while the time fraction rule overpredicted creep-fatigue life as large as a factor of 30. To make a reliable estimation of the creep damage in actual components, use of ductility exhaustion method is strongly recommended. (author)

  6. Low Carbon-Economy Development: China's Pattern and Policy Selection

    International Nuclear Information System (INIS)

    Dou, Xiangsheng

    2013-01-01

    For a developing country such as China, it is important to select a fair pattern that is suitable for China's national conditions for low carbon-economy development, as it has a direct impact on the success (or not) of low carbon-economy development. This research shows that, under the real-life conditions of China's development, different development patterns should be practised depending on specific socioeconomic conditions. Among them, one of the most critical issues is how to make full use of natural forces, and thus the nature-oriented development pattern should be practised in full. At the same time, China should still practise either the single regional differential or the multi-regional linkage development pattern under different conditions and either the imposed or the induced development pattern at the different stages of development. - Highlights: • It is particularly important to select a suitable development pattern. • Nature-oriented development pattern should be selected. • Single regional differentiation-typed or multi-regional linkage-typed pattern should be selected. • Either the imposed pattern or the induced pattern of development will be selected

  7. Delivering a secure electricity supply on a low carbon pathway

    International Nuclear Information System (INIS)

    Boston, Andy

    2013-01-01

    The energy system can only be considered sustainable in the long term if it is low carbon, affordable and secure. These three create a complex trilemma for all stakeholders in the energy business who have to strike a careful balance without neglecting any one aspect. This discussion paper examines the issues surrounding security of supply of the power system which has received less attention than the other aspects. It looks at how threats and mitigation measures can be classified in terms of where they act on the supply chain and the timescale over which they act. Only by considering the full range of timescales from seconds to decades can the full picture emerge of the effects of new technologies on security of supply. An examination of blackouts over the past 40 years sheds light on the causes of failure to supply and the most vulnerable aspects of the supply chain. - Highlights: ► Energy systems are only sustainable if they are low carbon, affordable and secure. ► Threats to security can be classified by timescale and position in the supply chain. ► The impact of new technologies on security must be considered across all timescales. ► Recent blackouts show the network is most vulnerable and weather the leading cause

  8. A proposal to finance low carbon investment in Europe

    International Nuclear Information System (INIS)

    Aglietta, Michel; Espagne, Etienne; Perrissin Fabert, Baptiste

    2015-02-01

    This year, Europe is confronted with a critical double challenge: addressing the climate change issue and pulling itself out of a persistent low growth trap. Today these two challenges are addressed separately. On the one hand, climate negotiations must reach a historical agreement in the Paris conference in December 2015. On the other hand, the Juncker Plan of 315 billion euros of investment, and above all the ECB announcement of a massive purchase of assets for an amount of around 1100 billion euros, must help to avoid a deflationary spiral and stimulate a new flow of investments. Regarding climate policies, public regulators have essentially focused on a carbon price, which remains today at an insufficient level to trigger the financing needs of the low carbon transition. The potential of the banking and saving channels (targets of the asset purchase program of the ECB) to scale up climate finance is however neglected. This 'Note d'analyse' proposes to make private low-carbon assets eligible for the ECB asset purchase program. The carbon impact of these assets would benefit from a public guarantee that would value their carbon externality at a level sufficient to compensate the absence of an adequate carbon price. This mechanism would immediately impact the investment decisions of private actors with a positive effect on growth. It would also strongly incite governments to progressively implement carbon pricing tools to ensure that the public backing of the value of the carbon assets remains neutral with respect to public budgets. (authors)

  9. Paving the way for low-carbon development strategies

    International Nuclear Information System (INIS)

    Van Tilburg, X.; Wuertenberger, L.; De Coninck, H.; Bakker, S.

    2011-09-01

    The aim of this report is to help move forward the discussion on low-carbon development strategies (LCDS) towards a useful climate policy instrument. It does so through a historical perspective on the use of an LCDS in a national and international context in order to provide high-level guidance to governments and experts who plan the development of an LCDS. The ultimate aim of a low-carbon development strategy is to catalyse concrete actions that support development with lower emissions. Therefore the process of LCDS development should not focus narrowly on producing a strategy document. Depending on the national context, an LCDS can serve different audiences and have different purposes, adding robustness to the attainment of mitigation actions. Rather than specifying a target or producing a document, an LCDS should provide a process that, depending on the developing country's readiness, meets needs to develop and to fill capacity, knowledge and information gaps. It should bring stakeholders from government, the private sector and civil society on the same page and eventually lead to greenhouse gas emissions that are lower compared to the situation in which the LCDS process had not been undertaken. International support could be sought for an LCDS process, but should not be made obligatory.

  10. Key factors of low carbon development strategy for sustainable transport

    Science.gov (United States)

    Thaveewatanaseth, K.; Limjirakan, S.

    2018-02-01

    Cities become more vulnerable to climate change impacts causing by urbanization, economic growth, increasing of energy consumption and carbon dioxide (CO2) emissions. People who live in the cities have already been affected from the impacts in terms of socioeconomic and environmental aspects. Sustainable transport plays the key role in CO2 mitigation and contributes positive impacts on sustainable development for the cities. Several studies in megacities both in developed and developing countries support that mass transit system is an important transportation mode in CO2 mitigation and sustainable transport development. This paper aims to study key factors of low carbon development strategy for sustainable transport. The Bangkok Mass Rapid Transit System (MRT) located in Bangkok was the study area. Data collection was using semi-structured in-depth interview protocol with thirty respondents consisting of six groups i.e. governmental agencies, the MRT operators, consulting companies, international organizations, non-profit organizations, and experts. The research findings highlighted the major factors and supplemental elements composing of institution and technical capacity, institutional framework, policy setting and process, and plan of implementation that would support more effective strategic process for low carbon development strategy (LCDS) for sustainable transport. The study would highly recommend on readiness of institution and technical capacities, stakeholder mapping, high-level decision- makers participation, and a clear direction of the governmental policies that are strongly needed in achieving the sustainable transport.

  11. Methodological review of UK and international low carbon scenarios

    International Nuclear Information System (INIS)

    Hughes, Nick; Strachan, Neil

    2010-01-01

    Scenarios have a long history in business, politics and military planning, as a tool for strategic planning to inform protective, proactive or consensus-based decision making in the face of uncertain futures. Recent years have seen a growth in scenarios for assessing the implications of low carbon futures, but relatively little work has linked these energy scenarios to the broader literature on scenario development. This paper undertakes a methodological review of a selection of UK and international low carbon scenario studies, using a typology of 'trend based', 'technical feasibility' and 'modelling' studies. Dominant methodologies in such studies have been the 2x2 axis and the 'back-casting' approach. Strengths of the studies reviewed include technological detail, and identification of key economic and social constraints. Weaknesses include the over-reliance on constructs such as exogenous emissions constraints, and high level trends, which diminish the ability to understand how the various future scenarios could be brought about or avoided. This is compounded by the lack of depiction of specific system actors; the tendency to abstract policy from the scenarios; and the resulting failure to consider policy, technology and behaviour in an iterative, 'co-evolving' fashion.

  12. Scenarios for low carbon and low water electric power plant ...

    Science.gov (United States)

    In the water-energy nexus, water use for the electric power sector is critical. Currently, the operational phase of electric power production dominates the electric sector's life cycle withdrawal and consumption of fresh water resources. Water use associated with the fuel cycle and power plant equipment manufacturing phase is substantially lower on a life cycle basis. An outstanding question is: how do regional shifts to lower carbon electric power mixes affect the relative contribution of the upstream life cycle water use? To test this, we examine a range of scenarios comparing a baseline with scenarios of carbon reduction and water use constraints using the MARKet ALlocation (MARKAL) energy systems model with ORD's 2014 U.S. 9-region database (EPAUS9r). The results suggest that moving toward a low carbon and low water electric power mix may increase the non-operational water use. In particular, power plant manufacturing water use for concentrating solar power, and fuel cycle water use for biomass feedstock, could see sharp increases under scenarios of high deployment of these low carbon options. Our analysis addresses the following questions. First, how does moving to a lower carbon electricity generation mix affect the overall regional electric power water use from a life cycle perspective? Second, how does constraining the operational water use for power plants affect the mix, if at all? Third, how does the life cycle water use differ among regions under

  13. Positioning Nuclear Power in the Low-Carbon Electricity Transition

    Directory of Open Access Journals (Sweden)

    Aviel Verbruggen

    2017-01-01

    Full Text Available Addressing climate change requires de-carbonizing future energy supplies in an increasingly energy-dependent world. The IEA and the IPCC (2014 mention the following as low-carbon energy supply options: ‘renewable energy, nuclear power and fossil fuels with carbon capture and storage’. Positioning nuclear power in the decarbonization transition is a problematic issue and is overridden by ill-conceived axioms. Before probing these axioms, we provide an overview of five major, postwar energy-related legacies and some insight into who is engaged in nuclear activities. We check whether low-carbon nuclear power passes the full sustainability test and whether it is compatible with the unfettered deployment of variable renewable power sourced from the sun and from wind and water currents, which delivers two negative answers. We show that the best approach of the sustainable energy transition was Germany’s 2011 decision to phase out nuclear power for a fast development and full deployment of renewable power. This is the best approach for the sustainable energy transition. We offer five practical suggestions to strengthen and accelerate carbon- and nuclear-free transitions. They are related to institutional issues like the role of cost-benefit analysis and the mission of the International Atomic Energy Agency, to the costs of nuclear risks and catastrophes, and to the historical record of nuclear technology and business.

  14. Distribution of Stress in Deformation Zone of Niobium Microalloyed Steel

    Science.gov (United States)

    Jandrlić, Ivan; Rešković, Stoja; Brlić, Tin

    2018-07-01

    Microalloyed steels today represent a significant part of total world production and processing of steel. Although widely used, there are scarce data on the stress distribution in the deformation zone of these steels. Research was carried out on two steel grades, both low-carbon structural steels with the same basic chemical composition, with one of them additionally microalloyed with niobium. Differences in the stress distribution in the deformation zone between two tested steels were continuously observed and measured using the methods of digital image correlation and thermography. It has been found out that niobium microalloyed steel has significantly more complex material flow and stress distribution in the deformation zone when compared to the plain low carbon steel.

  15. Distribution of Stress in Deformation Zone of Niobium Microalloyed Steel

    Science.gov (United States)

    Jandrlić, Ivan; Rešković, Stoja; Brlić, Tin

    2018-03-01

    Microalloyed steels today represent a significant part of total world production and processing of steel. Although widely used, there are scarce data on the stress distribution in the deformation zone of these steels. Research was carried out on two steel grades, both low-carbon structural steels with the same basic chemical composition, with one of them additionally microalloyed with niobium. Differences in the stress distribution in the deformation zone between two tested steels were continuously observed and measured using the methods of digital image correlation and thermography. It has been found out that niobium microalloyed steel has significantly more complex material flow and stress distribution in the deformation zone when compared to the plain low carbon steel.

  16. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Stradomski Z.

    2013-09-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  17. Research of low-carbon transition path of star hotels--A case study of Guilin

    Directory of Open Access Journals (Sweden)

    Tang Fengling

    2016-01-01

    Full Text Available A general trend of the world economic development is the low-carbon economic transition. With a wide influencing range and rapid development, the hotel industry has prominent problems in the energy con-sumption, resources occupancy and environmental unfriendliness, so it is imperative to develop low-carbon ho-tels. This paper proposes the low-carbon transition of the star hotels in Guilin in terms of constructing the energy conservation and innovative management mode, adopting new technologies and ways, developing low-carbon hotel products and guiding low-carbon consumption through analysis about the inevitability of establishing low-carbon hotels in Guilin, the running status of the existing star hotels and the situation of energy consumption, thus further promoting the development of low-carbon tourism in Guilin.

  18. Impacts of Low-Carbon Innovation and Its Heterogeneous Components on CO2 Emissions

    Directory of Open Access Journals (Sweden)

    Zheming Yan

    2017-04-01

    Full Text Available This paper aims to investigate the impact of low-carbon innovation on CO2 emissions. Using patent statistics, we measured low-carbon innovations for 15 major economies during the period of 1992–2012. Then, we classified low-carbon technology into clean and gray technology according to the patent classification system. Following the empirical Environmental Kuznets Curve (EKC framework, we explored the effects of low-carbon innovation and its components on CO2 emissions. We did not find any evidence of significant influence of low-carbon innovation. Through further estimations, a significantly negative effect of clean innovation was found while the effect of gray innovation is not clear. Heterogeneous impacts within low-carbon technology provide an explanation for the insignificant impact of low-carbon innovation.

  19. Investing for a low carbon economy. Special issue COP21

    International Nuclear Information System (INIS)

    Guez, Herve; Basselier, Clotilde; Bennani, Zineb; Coeslier, Manuel; Dufour, Mathilde; Dunand-Chatellet, Lea; Guez, Herve; Lauverjat Celine; Ostiari, Emmanuelle; Smia, Ladislas; Bonnin, Marguerite; Briand, Marc; Favier, Julien; Finidori, Esther; Wigley, Chris; Dobie, Jacqueline; Mary Ellis, Susannah; Kiernan, Shannon; Lefer, Elizabeth; Perrin, Elsa; Treadwell, Christopher; Zerner, Rachel

    2015-11-01

    Mirova, an asset management firm dedicated to responsible investment, has published today Investing in a low-carbon economy, a guide for investors to become COP21 compliant. Mirova's study provides an in-depth analysis highlighting the challenges of climate change and presents methods for investors to effectively measure their carbon footprint. Mirova offers a unique range of investment solutions promoting energy transition across all asset classes. COP21: mobilising private investors is a necessity To maintain the economy in a '2 degree' trajectory, it is vital to redirect savings towards companies and projects promoting energy transition. Philippe Zaouati, Head of Mirova explains: 'The energy transition can only succeed if we manage to mobilise private investors' savings. The success of COP21 therefore also depends on the ability of asset management firms to propose solutions in response to the climate challenge, whilst delivering the returns expected by investors'. Accurately measuring your carbon footprint. In response to growing demands on investors to make greener investments, Mirova, in partnership with the leading carbon strategy specialist consultant Carbone 4, has developed an innovative methodology to measure the carbon footprint of an investment portfolio. This decision-making tool assesses a company's contribution to the reduction of global greenhouse gas emissions (GGE). Measuring the overall impact of a business on the environment is an essential step towards acting against global warming. Assessing the carbon footprint is therefore an indispensable stage in the construction of portfolios contributing to energy transition. Low-carbon investments across all asset classes In order to redirect capital towards investments promoting energy transition, Mirova is proposing solutions involving all asset classes: - Renewable energy infrastructures: 100% low carbon allocation For more than 10 years now, Mirova has provided European institutions with access to

  20. Energy modelling towards low carbon development of Beijing in 2030

    DEFF Research Database (Denmark)

    Zhao, Guangling; Guerrero, Josep M.; Jiang, Kejun

    2017-01-01

    Beijing, as the capacity capital of China, is under the pressure of climate change and pollution. Nonrenewable energy generation and consumption is one of the most important sources of CO2 emissions, which cause climate changes. This paper presents a study on the energy system modeling towards...... scenario 2030, (ii) BAU (business as usual) scenario 2030 and (iii) RES (renewable energies) scenario 2030. The results shows that the share of renewables can increase to 100% of electricity and heat production in the RE scenario. The primary fuel consumption is reduced to 155.9 TWh, which is 72 % of fuel...... renewable energy and low carbon development for the city of Beijing. The analysis of energy system modeling is organized in two steps to explore the potential renewable energy alternative in Beijing. Firstly, a reference energy system of Beijing is created based on the available data in 2014. The Energy...

  1. Quantifying the UK's incentives for low carbon investment

    International Nuclear Information System (INIS)

    Wordsworth, Andrew; Grubb, Michael

    2003-01-01

    The UK climate change programme has introduced a range of instruments to foster investment in low carbon technologies and markets. We estimate the total value of these interventions, in terms of the redirection of financial flows and directly foregone tax income, to be about 1.3 billion pounds per year (Euro or US$: 2 billion per year), as from 2002 to 2003 when the renewable obligation certificates (ROCs) first take effect. About 20% of this consists of direct expenditure, the remaining 80% is in the form of indirect expenditures contained within sectors (ROCs, the energy efficiency commitments), and foregone tax revenues. Most of the energy-efficiency investment is estimated to recoup expenditure within normal life-cycles and may thus be considered profitable; the profitability of the supply-side interventions is predicated mostly upon expected cost reductions associated with the build up of the associated industries

  2. Assessment of technologies to meet a low carbon fuel standard.

    Science.gov (United States)

    Yeh, Sonia; Lutsey, Nicholas P; Parker, Nathan C

    2009-09-15

    California's low carbon fuel standard (LCFS) was designed to incentivize a diverse array of available strategies for reducing transportation greenhouse gas (GHG) emissions. It provides strong incentives for fuels with lower GHG emissions, while explicitly requiring a 10% reduction in California's transportation fuel GHG intensity by 2020. This paper investigates the potential for cost-effective GHG reductions from electrification and expanded use of biofuels. The analysis indicates that fuel providers could meetthe standard using a portfolio approach that employs both biofuels and electricity, which would reduce the risks and uncertainties associated with the progress of cellulosic and battery technologies, feedstock prices, land availability, and the sustainability of the various compliance approaches. Our analysis is based on the details of California's development of an LCFS; however, this research approach could be generalizable to a national U.S. standard and to similar programs in Europe and Canada.

  3. Low-carbon energy generates public health savings in California

    Science.gov (United States)

    Zapata, Christina B.; Yang, Chris; Yeh, Sonia; Ogden, Joan; Kleeman, Michael J.

    2018-04-01

    California's goal to reduce greenhouse gas (GHG) emissions to a level that is 80 % below 1990 levels by the year 2050 will require adoption of low-carbon energy sources across all economic sectors. In addition to reducing GHG emissions, shifting to fuels with lower carbon intensity will change concentrations of short-lived conventional air pollutants, including airborne particles with a diameter of less than 2.5 µm (PM2.5) and ozone (O3). Here we evaluate how business-as-usual (BAU) air pollution and public health in California will be transformed in the year 2050 through the adoption of low-carbon technologies, expanded electrification, and modified activity patterns within a low-carbon energy scenario (GHG-Step). Both the BAU and GHG-Step statewide emission scenarios were constructed using the energy-economic optimization model, CA-TIMES, that calculates the multi-sector energy portfolio that meets projected energy supply and demand at the lowest cost, while also satisfying scenario-specific GHG emissions constraints. Corresponding criteria pollutant emissions for each scenario were then spatially allocated at 4 km resolution to support air quality analysis in different regions of the state. Meteorological inputs for the year 2054 were generated under a Representative Concentration Pathway (RCP) 8.5 future climate. Annual-average PM2.5 and O3 concentrations were predicted using the modified emissions and meteorology inputs with a regional chemical transport model. In the final phase of the analysis, mortality (total deaths) and mortality rate (deaths per 100 000) were calculated using established exposure-response relationships from air pollution epidemiology combined with simulated annual-average PM2.5 and O3 exposure. Net emissions reductions across all sectors are -36 % for PM0.1 mass, -3.6 % for PM2.5 mass, -10.6 % for PM2.5 elemental carbon, -13.3 % for PM2.5 organic carbon, -13.7 % for NOx, and -27.5 % for NH3. Predicted deaths associated with air

  4. Quantifying the UK's incentives for low carbon investment

    International Nuclear Information System (INIS)

    Wordworth, A.; Grubb, M.

    2003-01-01

    The UK climate change programme has introduced a range of instruments to foster investment in low carbon technologies and markets. We estimate the total value of these interventions, in terms of the redirection of financial flows and directly foregone tax income, to be about 1.3 billion English pounds per year (c. Euro or US$ 2 billion per year), as from 2002 to 2003 when the renewable obligation certificates (ROCs) first take effect. About 20% of this consists of direct expenditure, the remaining 80% is in the form of indirect expenditures contained within sectors (ROCs, the energy efficiency commitments), and foregone tax revenues. Most of the energy-efficiency investment is estimated to recoup expenditure within normal life-cycles and may thus be considered profitable; the profitability of the supply-side interventions is predicated mostly upon expected cost reductions associated with the build up of the associated industries

  5. Low-carbon energy generates public health savings in California

    Directory of Open Access Journals (Sweden)

    C. B. Zapata

    2018-04-01

    Full Text Available California's goal to reduce greenhouse gas (GHG emissions to a level that is 80 % below 1990 levels by the year 2050 will require adoption of low-carbon energy sources across all economic sectors. In addition to reducing GHG emissions, shifting to fuels with lower carbon intensity will change concentrations of short-lived conventional air pollutants, including airborne particles with a diameter of less than 2.5 µm (PM2.5 and ozone (O3. Here we evaluate how business-as-usual (BAU air pollution and public health in California will be transformed in the year 2050 through the adoption of low-carbon technologies, expanded electrification, and modified activity patterns within a low-carbon energy scenario (GHG-Step. Both the BAU and GHG-Step statewide emission scenarios were constructed using the energy–economic optimization model, CA-TIMES, that calculates the multi-sector energy portfolio that meets projected energy supply and demand at the lowest cost, while also satisfying scenario-specific GHG emissions constraints. Corresponding criteria pollutant emissions for each scenario were then spatially allocated at 4 km resolution to support air quality analysis in different regions of the state. Meteorological inputs for the year 2054 were generated under a Representative Concentration Pathway (RCP 8.5 future climate. Annual-average PM2.5 and O3 concentrations were predicted using the modified emissions and meteorology inputs with a regional chemical transport model. In the final phase of the analysis, mortality (total deaths and mortality rate (deaths per 100 000 were calculated using established exposure-response relationships from air pollution epidemiology combined with simulated annual-average PM2.5 and O3 exposure. Net emissions reductions across all sectors are −36 % for PM0.1 mass, −3.6 % for PM2.5 mass, −10.6 % for PM2.5 elemental carbon, −13.3 % for PM2.5 organic carbon, −13.7 % for NOx, and −27.5 % for NH3

  6. Barriers and possibilities for low-carbon-energy consuming technologies

    DEFF Research Database (Denmark)

    Bjarklev, Araceli

    consensus that one of the solutions to the current environmental challenge will be based on low-carbon-technologies, there are many issues that set a barrier for its adequate development and still many actors in these sectors are sceptical about the possibilities. Illumination is a very interesting sector...... to target, since it uses 19% of the total electricity produced in the world. Consequently, this paper takes the Danish office lighting sector as a study object and discusses the question: What are the main barriers and possibilities for the energy saving illumination technologies to efficiently reduce...... their ecological footprint. The discussion is supported by using relevant elements of the cradle-to-grave, eco-design and environmental-innovation theories. It is based on active participation in interdisciplinary projects and face-to-face in-depth interviews with relevant actors along the entire Danish...

  7. Extension classification method for low-carbon product cases

    Directory of Open Access Journals (Sweden)

    Yanwei Zhao

    2016-05-01

    Full Text Available In product low-carbon design, intelligent decision systems integrated with certain classification algorithms recommend the existing design cases to designers. However, these systems mostly dependent on prior experience, and product designers not only expect to get a satisfactory case from an intelligent system but also hope to achieve assistance in modifying unsatisfactory cases. In this article, we proposed a new categorization method composed of static and dynamic classification based on extension theory. This classification method can be integrated into case-based reasoning system to get accurate classification results and to inform designers of detailed information about unsatisfactory cases. First, we establish the static classification model for cases by dependent function in a hierarchical structure. Then for dynamic classification, we make transformation for cases based on case model, attributes, attribute values, and dependent function, thus cases can take qualitative changes. Finally, the applicability of proposed method is demonstrated through a case study of screw air compressor cases.

  8. Study on multimodal transport route under low carbon background

    Science.gov (United States)

    Liu, Lele; Liu, Jie

    2018-06-01

    Low-carbon environmental protection is the focus of attention around the world, scientists are constantly researching on production of carbon emissions and living carbon emissions. However, there is little literature about multimodal transportation based on carbon emission at home and abroad. Firstly, this paper introduces the theory of multimodal transportation, the multimodal transport models that didn't consider carbon emissions and consider carbon emissions are analyzed. On this basis, a multi-objective programming 0-1 programming model with minimum total transportation cost and minimum total carbon emission is proposed. The idea of weight is applied to Ideal point method for solving problem, multi-objective programming is transformed into a single objective function. The optimal solution of carbon emission to transportation cost under different weights is determined by a single objective function with variable weights. Based on the model and algorithm, an example is given and the results are analyzed.

  9. Status and outlook for Thailand's low carbon electricity development

    International Nuclear Information System (INIS)

    Sawangphol, Narumitr; Pharino, Chanathip

    2011-01-01

    Thailand is facing an urgency to enhance its energy security and capacity to cope with global warming impacts, as demands on fossil fuel consumption keep rising. This paper reviewed the latest situation on renewable powers and developmental strategies toward low carbon electricity generation in Thailand. Government recently has spent tremendous financial and legislative supports to promote the uses of indigenous renewable energy resources and fuel diversification while contributing in reduction of global greenhouse gas. Major policy challenge is on which types of renewable energy should be more pronounced to ensure sustainable future of the country. Regions in Thailand present different potentials for renewable supply on biomass, municipal wastes, hydropower, and wind. To maximize renewable energy development in each area, location is matter. Currently, energy-derived biomass is widely utilized within the country, however if droughts happen more often and severe, it will not only affect food security but also energy security. Life cycle of biomass energy production may cause other social issues on land and chemical uses. Meanwhile, deployment of wind and solar energy has been slow and needs to speed up to the large extent in comparison with energy proportion from biomass. Nuclear power has already been included in the Thai power development plan 2010 (PDP-2010). However, public acceptance is a major issue. Setting up strategic renewable energy zone to support power producer according to pre-determined potential location may assist development direction. Furthermore, government has to strongly subsidize research and development to lower technology cost and promote private investment on renewable energy industry. In the future, revision of electricity price is needed to allow fair competition between non-renewable and renewable energy once subsidy programs are ended. Environmental tax according to fuel types could help government progressing toward low carbon

  10. Critical Metals in Strategic Low-carbon Energy Technologies

    Science.gov (United States)

    Moss, R. L.

    2012-04-01

    Due to the rapid growth in demand for certain materials, compounded by political risks associated with the geographical concentration of the supply of them, shortages of materials could be a potential bottleneck to the deployment of low-carbon energy technologies. Consequently, an assessment has been carried out to ascertain whether such shortages could jeopardise the objectives of the EU's Strategic Energy Technology Plan (SET-Plan), especially in the six low-carbon energy technologies of SET-Plan, namely: nuclear, solar, wind, bioenergy, carbon capture and storage (CCS) and electricity grids. The assessment identified 14 metals for which the deployment of the six technologies will require 1% or more (and in some cases, much more) of current world supply per annum between 2020 and 2030. Following a more critical examination, based on the likelihood of rapid future global demand growth, limitations to expanding supply in the short to medium term, and the concentration of supply and political risks associated with key suppliers, 5 of the 14 metals were pinpointed to be at high risk, namely: the rare earth metals neodymium and dysprosium (for wind technology), and the by-products (from the processing of other metals) indium, tellurium and gallium (for photovoltaic technologies). In addition, the work has explored potential mitigation strategies, ranging from expanding European output, increasing recycling and reuse to reducing waste and finding substitutes for these metals in their main applications. Furthermore, recommendations are provided which include closely working with the EU's Raw Materials Initiative; supporting efforts to ensure reliable supply of ore concentrates at competitive prices; promoting R&D and demonstration projects on new lower cost separation processes; and promoting the further development of recycling technologies and increasing end-of-life collection

  11. Gauging citizen support for a low carbon fuel standard

    International Nuclear Information System (INIS)

    Rhodes, Ekaterina; Axsen, Jonn; Jaccard, Mark

    2015-01-01

    Since 2007, several variations of a low carbon fuel standard (LCFS) have been implemented around the world. While emerging research tends to focus on greenhouse gas emission reductions from an LCFS, no studies have assessed the policy's political acceptability—a critical component of implementation. We elicit public support for an existing LCFS in British Columbia and a hypothetical (proposed) LCFS for the rest of Canada using survey data collected from a representative sample of Canadian citizens (n=1306). Specifically, we assess: (1) citizen awareness of British Columbia's LCFS, (2) stated citizen support for the LCFS, and (3) how individual characteristics relate to levels of citizen support. We find that British Columbia's LCFS is almost unknown among British Columbia respondents, but once explained, 90% of respondents support it. We refer to this combination of low knowledge and high support as “passive support.” We find similarly broad support in all other Canadian provinces, implying that citizen opposition is unlikely in jurisdictions considering an LCFS. Statistical analysis identifies some individual characteristics associated with LCFS support, including attitudes, demographics, and contextual factors. Results indicate where policymakers might anticipate opposition if it arises due to increased policy stringency or media coverage. - Highlights: • Most citizens are unaware of British Columbia's low carbon fuel standard (LCFS). • We observe passive support: low awareness and high support of the policy. • An LCFS achieves broad support among British Columbia's and Canadian citizens. • Households relying on single occupancy vehicles are less likely to support an LCFS

  12. Microbiological corrosion in low carbon steels; Corrosion microbiologica en aceros de bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Medina-Custodio, O; Ortiz-Prado, A; Jacobo-Armendariz, V. H; Schouwenaars-Franssens, R [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: medina_1979@yahoo.com; armandoo@servidor.unam.mx; vjacobo@dgapa.unam.mx; raf_schouweenaars@yahoo.com

    2009-01-15

    The Microbiologically Induced Corrosion affects several industries, such as oil industry where it is estimated that 20% to 30% pipes failures are related with microorganism. The chemical reactions generate ions transfer, this validate the use of electrochemical technique for its analysis. Coupons submerged in a nutritional medium with presence and absence of three different microorganisms during two periods, 48 hours and 28 days were studied. Polarization resistance (Rp) and Electrochemical Impedance Spectroscopy (EIS) techniques were applied to determine the corrosively of the systems. The results show a greater corrosive effect of abiotic systems, this indicates a microorganisms protection effect to the metal, opposite to the first hypothesis. This result was ratified observing surface coupons by using Scanning Electron Microscopy (SEM) technique. A possible mechanism based on Evans - Tafel graph is proposed to explain inhibitor microorganism effect. [Spanish] La corrosion microbiologica es un tipo comun de deterioro que afecta diversas industrias, una de ellas es la petrolera en la que se estiman que el 20% o 30% de fallas en las tuberias de trasporte de hidrocarburos es favorecida por microorganismos. Las reacciones quimicas que sustentan estos, generan transferencia de iones, lo que justifica el empleo de tecnicas electroquimicas para su analisis. En este trabajo, se estudiaron probetas de acero de bajo carbono SAE 1018, sumergidas en un medio nutritivo rico en cloruros en presencia y ausencia de tres diferentes cargas microbianas, en tiempos de exposicion de 48 horas y 28 dias. Se realizaron ensayos de resistencia a la polarizacion (Rp) y espectroscopia de impedancia electroquimica (EIS) para determinar el efecto corrosivo de los diferentes sistemas. Los resultados muestran que el medio abiotico causa el mayor efecto corrosivo, lo que indica un efecto protector de los microorganismos al metal contradiciendo la hipotesis inicialmente propuesta. La observacion de las superficies en el microscopio electronico de barrido (MEB) apoya lo obtenido por las tecnicas electroquimicas. Para explicar la disminucion de la corrosividad del medio en presencia de microorganismos se propone un posible mecanismo de polarizacion catodica.

  13. Growth modes of individual ferrite grains in the austenite to ferrite transformation of low carbon steels

    International Nuclear Information System (INIS)

    Li, D.Z.; Xiao, N.M.; Lan, Y.J.; Zheng, C.W.; Li, Y.Y.

    2007-01-01

    The mesoscale deterministic cellular automaton (CA) method and probabilistic Q-state Potts-based Monte Carlo (MC) model have been adopted to investigate independently the individual growth behavior of ferrite grain during the austenite (γ)-ferrite (α) transformation. In these models, the γ-α phase transformation and ferrite grain coarsening induced by α/α grain boundary migration could be simulated simultaneously. The simulations demonstrated that both the hard impingement (ferrite grain coarsening) and the soft impingement (overlapping carbon concentration field) have a great influence on the individual ferrite growth behavior. Generally, ferrite grains displayed six modes of growth behavior: parabolic growth, delayed nucleation and growth, temporary shrinkage, partial shrinkage, complete shrinkage and accelerated growth in the transformation. Some modes have been observed before by the synchrotron X-ray diffraction experiment. The mesoscopic simulation provides an alternative tool for investigating both the individual grain growth behavior and the overall transformation behavior simultaneously during transformation

  14. Lewis Acid-Base Properties of a Low Carbon Aluminium Killed Steel ...

    African Journals Online (AJOL)

    An important factor in achieving maximum adhesion of a particular coating system to the substrate lies in the proper preparation of the substrate prior to the application of paint. The Lewis acid-base properties of the outer metal surface play a determinant role in many of these applications, and the chemical reactions involved ...

  15. Apparent Fracture Toughness of Low-carbon Steel CSN 411353 as Related to Stress Corrosion Cracks

    Czech Academy of Sciences Publication Activity Database

    Gajdoš, Lubomír; Šperl, Martin; Siegl, J.

    2011-01-01

    Roč. 32, 8/9 (2011), s. 4348-4353 ISSN 0261-3069 R&D Projects: GA ČR(CZ) GAP105/10/2052; GA ČR(CZ) GPP105/10/P555 Grant - others:GAMPO(CZ) FT-TA5/076 Program:FT Institutional research plan: CEZ:AV0Z20710524 Keywords : corrosion * fracture * fractography Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.200, year: 2011

  16. EFFECT OF STRAIN RATE ON MICROSTRUCTURE OF A LOW CARBON STEEL WIRE

    Directory of Open Access Journals (Sweden)

    H BOUHALAIS

    2011-12-01

    microstructure of the material in as received and deformed conditions. It is found that tensile properties depend on the wiredrawing area reduction (τw. The annealing temperatures and the grain size are determined; they also vary with τw .

  17. A Low Carbon EU Energy System and Unconventional Sources

    International Nuclear Information System (INIS)

    Gracceva, F.; Kanudia, A.; Tosato, GC.

    2013-01-01

    The paper investigates the potential role of unconventional fossil fuels in a global low carbon energy system. Making use of a systemic approach, the paper presents an original application of a global partial equilibrium energy system model (TIAM-JET). In order to give a worldwide perspective with higher detail on European energy systems, the model links a set of extra-European macro-regions to the 30 European countries. First, a review of the most recent estimates of the available stocks of unconventional hydrocarbon resources is used to build the set of assumption for the scenario analysis. Secondly, a set of scenarios assuming different availability and cost of unconventional fuels are added to both a Current Trend scenario and a Carbon Constrained (CC) scenario, to explore the perspectives of unconventional gas and oil in a scenario halving CO 2 emissions by 2050, which is consistent with a 2 degree temperature increase. The results show if/how unconventional sources can contribute to the robustness of the European energy system with respect to the stress of a strong carbon constraint. We define this robustness as the capacity of the energy system to adapt its evolution to long-term constraints and keep delivering energy services to end users. In our approach robustness represents the long-term dimension of energy security. Assessing this ''system property'' requires analysing the wide range of factors that can exercise a stabilizing influence on the energy services delivery system, together with their relations, actual interactions and synergies. The energy system approach used for the analysis seeks to take into account as much of this complexity as possible. We assess the robustness of the EU system to the carbon constraint by looking at how the CC scenario affects energy system costs and energy prices under scenarios with different deployment of unconventional sources. This provides insights on the synergies and/or trade-offs between energy security and

  18. The US Electricity Industry and the Low-Carbon Transition

    International Nuclear Information System (INIS)

    Mathieu, Carole

    2016-04-01

    While the wave of liberalisation produced a fragmented, but now stabilised, industrial landscape, the US power sector is about to undergo another major transformation with the low-carbon transition. Against a background of combined weak demand for electricity, a boom in distributed solar PV power and a decline in the profitability of merchant assets, incumbent stakeholders are currently dealing with further questions about the future of their business models. Driven as much by market forces as by government support mechanisms, these destabilising factors have an impact, which is still difficult to assess, but the need to control future transformation is already at the heart of debate. In areas where output is priced on the wholesale markets, new tools are being studied to secure compensation for some power stations, with the issue of possible excessive dependency on natural gas in the background. At the same time, an increasing number of states are questioning the design of their support mechanisms for distributed energy. If net metering, the main support mechanism for distributed solar PV power, has been a resounding success because of its simplicity, it is now criticised because of the problems of covering grid costs and the cross-subsidies it leads to. Although reforms are always difficult to implement, since they involve a conflict of increasingly organised interests, consensus is beginning to emerge regarding the structure of retail sales tariffs. Nevertheless, calls for an assessment of distributed generation according to its actual value for the system are increasing, without any real convergence of views on the methodology to be adopted to date. Conventional stakeholders are also looking to adapt in order to find growth opportunities where primarily only challenges appear. The diversification of activities is an important lever for transformation, even if the case of NRG Energy illustrates the difficulty in making strategic shifts while maintaining

  19. On the Market Failures during the Development of Low-Carbon Economy

    Institute of Scientific and Technical Information of China (English)

    LU Xian-xiang; KE Zan-xian; ZHANG Yi

    2014-01-01

    Greenhouse gas emissions and the development of low-carbon economy are the biggest market failures,which are mainly manifested in such problems as the low-carbon economy being the world's largest externality,the low-carbon economy being the global public goods,and the free-rider along the development of low-carbon economy.The major reason for the market failures during the development of low-carbon economy is lacking of secured property ownership as well as the greenhouse effect.Thus,in order to establish secured property rights through institutional innovation,it is necessary not only to reduce the exploitation of fossil fuels from the source,but also to allocate the emission rights fairly.To develop the low-carbon economy is faced with market failures,but we can not therefore deny the basic roles of the market mechanism in the development of low-carbon economy,rather to correct and adjust the market through institutional innovations,so as to facilitate the establishment and operation of the low-carbon economy.For the sake of the sustainable development of human society,we have to adjust or change the rules of the resource allocation in the market economy,embedding such factors as emission reduction,low-carbon,environmental protection,etc.into the institutional framework of the market via rules,systems and policies.

  20. China in the transition to a low-carbon economy

    International Nuclear Information System (INIS)

    Zhang Zhongxiang

    2010-01-01

    China, from its own perspective cannot afford to and, from an international perspective, is not allowed to continue on the conventional path of encouraging economic growth at the expense of the environment. Instead, China needs to transform its economy to effectively address concern about a range of environmental problems from burning fossil fuels and steeply rising oil import and international pressure on it to exhibit greater ambition in fighting global climate change. This paper first discusses China's own efforts towards energy saving and pollutants cutting, the widespread use of renewable energy and participation in clean development mechanism, and puts carbon reductions of China's unilateral actions into perspective. Given that that transition to a low carbon economy cannot take place overnight, the paper then discusses China's policies on promoting the use of clean coal technologies and nuclear power. Based on these discussions, the paper provides some recommendations on issues related to energy conservation and pollution control, wind power, nuclear power and clean coal technologies and articulates a roadmap for China regarding its climate commitments to 2050.

  1. Challenges to China's transition to a low carbon electricity system

    International Nuclear Information System (INIS)

    Kahrl, Fredrich; Williams, Jim; Ding Jianhua; Hu Junfeng

    2011-01-01

    We examine the challenges to China's transition to a low carbon electricity system, in which renewable energy would play a significant role. China's electricity system currently lacks the flexibility in planning, operations, and pricing to respond to conflicting pressures from demand growth, rising costs, and environmental mandates in a way that simultaneously maintains reliability, decarbonizes the system, and keeps prices within acceptable bounds. Greater flexibility crucially requires the ability to more systematically and transparently manage and allocate costs. This will require re-orientating sector institutions still rooted in central planning, and strengthening independent regulation. Some of the necessary changes require fundamental political and legal reforms beyond the scope of energy policy. However, the system's flexibility can still be increased through the development of traditional planning and regulatory tools and approaches, such as an avoided cost basis for energy efficiency investments, more integrated planning to improve the coordination of generation, transmission, and demand-side investments, and a transparent ratemaking process. The judicious application of OECD electricity sector experience and skills can support these developments. - Research highlights: → China's electricity system currently lacks the flexibility to integrate renewables and reduce CO 2 emissions on a large scale at an acceptable cost and level of reliability. → The challenges to increased flexibility are more institutional than technological. → Chinese government agencies need new approaches to basic power system planning and ratemaking. → OECD countries can help address these challenges through the transfer of 'soft' technologies.

  2. Nuclear energy for a low-carbon France

    International Nuclear Information System (INIS)

    Faudon, Valerie; Jouette, Isabelle; Le Ngoc, Boris

    2015-01-01

    This publication states the opinion of the SFEN (the French Society of Nuclear Energy) about the implementation of the French Multi-year Energy Programming (PPE). The authors first outline that the PPE must firstly aim at reducing greenhouse gas emissions. As a second point, they outline that the PPE must remain flexible in order to be able to face uncertainties related to supply (growth of renewable energies) and demand (economic recovery, pace of energetic installation renewal), and to guard against energy-related events (oil shocks, Russian-Ukrainian crisis, and so on) through a right planning of the energy mix diversification with taking the improvement of economic and technological performance of renewable energies into account. As a third point, they outline that nuclear energy is the base of a low-carbon France. They finally discuss perspectives to strengthen this base by a sustained investment in the nuclear fleet, in the fuel recycling sector, and in research for the development of a new generation of reactors

  3. Green growth: Policies for transition towards low carbon economies

    Energy Technology Data Exchange (ETDEWEB)

    Moe, Thorvald

    2012-11-01

    For the next fifty years and beyond, the world faces twin challenges: -Enhancing economic opportunities and living standards for a growing global population; -Addressing the environmental threats that, if left largely unaddressed, could undermine our abilities for longer term economic growth and development and the ability to reduce poverty. For twenty years the world community has attempted to face up to these challenges, notably global warming by a 'top down' international negotiation process under the auspices of the UN Framework Convention on Climate Change (UNFCCC). The paper discusses why this process has failed so far. To get out of this impasse, a 'bottom up' policy framework for green growth based on national preferences, possibilities and policies should be considered and is discussed in some detail. However, while green growth may enhance the transition towards low-carbon economies in the short and medium term, it is argued that a 'Global Green Deal' with regional and global rules of the game is needed to reduce the risk for unsustainable development in the longer term.(auth)

  4. Bridging analytical approaches for low-carbon transitions

    Science.gov (United States)

    Geels, Frank W.; Berkhout, Frans; van Vuuren, Detlef P.

    2016-06-01

    Low-carbon transitions are long-term multi-faceted processes. Although integrated assessment models have many strengths for analysing such transitions, their mathematical representation requires a simplification of the causes, dynamics and scope of such societal transformations. We suggest that integrated assessment model-based analysis should be complemented with insights from socio-technical transition analysis and practice-based action research. We discuss the underlying assumptions, strengths and weaknesses of these three analytical approaches. We argue that full integration of these approaches is not feasible, because of foundational differences in philosophies of science and ontological assumptions. Instead, we suggest that bridging, based on sequential and interactive articulation of different approaches, may generate a more comprehensive and useful chain of assessments to support policy formation and action. We also show how these approaches address knowledge needs of different policymakers (international, national and local), relate to different dimensions of policy processes and speak to different policy-relevant criteria such as cost-effectiveness, socio-political feasibility, social acceptance and legitimacy, and flexibility. A more differentiated set of analytical approaches thus enables a more differentiated approach to climate policy making.

  5. California's Low-Carbon Fuel Standard - Compliance Trends

    Science.gov (United States)

    Witcover, J.; Yeh, S.

    2013-12-01

    Policies to incentivize lower carbon transport fuels have become more prevalent even as they spark heated debate over their cost and feasibility. California's approach - performance-based regulation called the Low Carbon Fuel Standard (LCFS) - has proved no exception. The LCFS aims to achieve 10% reductions in state transport fuel carbon intensity (CI) by 2020, by setting declining annual CI targets, and rewarding fuels for incremental improvements in CI beyond the targets while penalizing those that fail to meet requirements. Even as debate continues over when new, lower carbon fuels will become widely available at commercial scale, California's transport energy mix is shifting in gradual but noticeable ways under the LCFS. We analyze the changes using available data on LCFS fuels from the California Air Resources Board and other secondary sources, beginning in 2011 (the first compliance year). We examine trends in program compliance (evaluated through carbon credits and deficits generated), and relative importance of various transport energy pathways (fuel types and feedstocks, and their CI ratings, including new pathways added since the program's start). We document a roughly 2% decline in CI for gasoline and diesel substitutes under the program, with compliance achieved through small shifts toward greater reliance on fuels with lower CI ratings within a relatively stable amount of transport energy derived from alternatives to fossil fuel gasoline and diesel. We also discuss price trends in the nascent LCFS credit market. The results are important to the broader policy debate about transportation sector response to market-based policies aimed at reducing the sector's greenhouse gas emissions.

  6. Scenarios of technology adoption towards low-carbon cities

    International Nuclear Information System (INIS)

    Mohareb, Eugene A.; Kennedy, Christopher A.

    2014-01-01

    Technological change has often been presented as a readily accepted means by which long-term greenhouse gas (GHG) emission reductions can be achieved. Cities are the future centers of economic growth, with the global population becoming predominantly urban; hence, increases or reductions of GHG emissions are tied to their energy strategies. This research examines the likelihood of a developed world city (the Greater Toronto Area) achieving an 80% reduction in GHG emissions through policy-enabled technological change. Emissions are examined from 3 major sources: light duty passenger vehicles, residential buildings and commercial/institutional buildings. Logistic diffusion curves are applied for the adoption of alternative vehicle technologies, building retrofits and high performance new building construction. This research devises high, low and business-as-usual estimates of future technological adoption and finds that even aggressive scenarios are not sufficient to achieve an 80% reduction in GHG emissions by 2050. This further highlights the challenges faced in maintaining a relatively stable climate. Urban policy makers must consider that the longer the lag before this transition occurs, the greater the share of GHG emissions mitigation that must addressed through behavioural change in order to meet the 2050 target, which likely poses greater political challenges. - Highlights: • Explores policy options in a city targeting an 80% GHG emission reduction target by 2050. • Aggressive building code changes will have minimal impact on GHG mitigation. • Support of low-carbon electricity for the majority of generation necessary by 2050. • Internal combustion engine use must be mostly eliminated from the vehicle stock. • Policies supporting elimination of physical exchange space should be promoted

  7. Analysis and study of low-carbon clothing design and fashion lifestyle

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2016-10-01

    Full Text Available Low-carbon is not only a slogan, but also a global action to protect the environment. In the clothing industry, low-carbon clothing design has drawn public focus and it also conveyed the notion that we should respect for nature and advocate the concept of conservation. Through the analysis and study of low-carbon clothing design, it comes to two conclusions: On the subjective aspect, low-carbon design consciousness of designers which humanization of costume design, design clothing beyond beauty, thinking and caring about people; on the objective aspects, low-carbon clothing design is analyzed in three main aspects: fabric, color and styling. It is necessary to put low-carbon concept into people’s behavior consciousness and let the slow fashion environmental concept return back to people’s fashion lifestyle, so that consumers can look for their self-positioning and rational thinking. Therefore, the design of low-carbon clothing should be raised to the design of humanistic care to ensure that low-carbon concept is a global need and responsibility.

  8. Designing trust: how strategic intermediaries choreograph homeowners’ low-carbon retrofit experience

    NARCIS (Netherlands)

    Wilde, de M.; Spaargaren, G.

    2018-01-01

    In the Netherlands, as in other European countries, the uncertain, fragmented character of the low-carbon retrofit market hampers a transition towards sustainable housing. Connecting homeowners to supply-side actors of low-carbon retrofit procedures, products and technologies in ways satisfactory to

  9. Impact assessment of the carbon reduction strategy for transport, low carbon transport : a greener future

    Science.gov (United States)

    2009-07-01

    This is an impact assessment for the Carbon Reduction Strategy for Transport (DfT, 2009), Low Carbon Transport: A Greener Future, which is part of the UK Governments wider UK Low Carbon Transition Plan (DECC, 2009), Britains path to ta...

  10. AC-Induced Bias Potential Effect on Corrosion of Steels

    Science.gov (United States)

    2009-02-05

    induction, variable conduction Experimental Setup Super- martensitic stainless steel composition Analysis: C Mn Si Cr Ni Mo Cu N Typical 13 Cr ɘ.01 0.6... stainless steel used in pipelines. •Low carbon (ɘ.01): allows the formation of a “soft” martensite that is more resistant than standard martensitic ...Proposed AC Corrosion Models  AC Simulated Corrosion testing  Stainless steel pipe and coating  Cathodic protection  Experimental Setup  Preliminary

  11. Industrial trial to produce a low clinker, low carbon cement

    Directory of Open Access Journals (Sweden)

    Vizcaíno-Andrés, L. M.

    2015-03-01

    Full Text Available A preliminary assessment of conditions for the industrial manufacture of a new cementitious system based on clinker-calcined clay and limestone, developed by the authors, referred as “low carbon cement” is presented. The new cement enables the substitution of more than 50% of the mass of clinker without compromising performance. The paper presents the follow-up of an industrial trial carried out in Cuba to produce 130 tonnes of the new cement at a cement plant. The new material proved to fulfill national standards in applications such as the manufacture of hollow concrete blocks and precast concrete. No major differences either in the rheological or mechanical properties were found when compared with Portland cement. Environmental assessment of the ternary cement was made, which included comparison with other blended cements produced industrially in Cuba. The new cement has proven to contribute to the reduction of above 30% of carbon emissions on cement manufacture.Se presenta la evaluación preliminar de las condiciones de fabricación industrial de un nuevo sistema cementicio a partir del empleo de clínquer; arcillas calcinadas y piedra caliza; desarrollado por los autores; denominado “cemento de bajo carbono”. El nuevo cemento posibilita la reducción de más de un 50% de la masa de clínquer; sin comprometer el comportamiento del material. El presente trabajo presenta el monitoreo de la producción industrial en una planta en Cuba; de 130 t del nuevo cemento. El cemento obtenido cumple con las regulaciones nacionales de calidad y su empleo tiene similar rendimiento que el cemento Pórtland para la producción de bloques y hormigón de 25 MPa. Se realiza el análisis de impacto ambiental del cemento ternario mediante la comparación con otros cementos producidos industrialmente. El nuevo cemento puede contribuir a la reducción de más del 30% de las emisiones de CO2 asociadas a la manufactura de cemento.

  12. Low carbon society scenario 2050 in Thai industrial sector

    International Nuclear Information System (INIS)

    Selvakkumaran, Sujeetha; Limmeechokchai, Bundit; Masui, Toshihiko; Hanaoka, Tatsuya; Matsuoka, Yuzuru

    2014-01-01

    Highlights: • Thai industrial sector has been modelled using AIM/Enduse model. • Potential mitigation of CO 2 for 2050 is approximately 20% from Baseline scenario. • Abatement cost curves show that varied counter measures are practical in the industrial sector. • Energy security is enhanced due to CO 2 mitigation in the LCS scenario. - Abstract: Energy plays a dominant role in determining the individual competitiveness of a country and this is more relevant to emerging economies. That being said, energy also plays an important and ever expanding role in carbon emissions and sustainability of the country. As a developing country Thailand’s industrial sector is vibrant and robust and consumes majority of the energy. In addition, it also has the highest CO 2 emissions, provided the emissions of power generation are taken into account. Industry also accounts for the highest consumption of electricity in Thailand. The objective of this study is to model the Thai industrial energy sector and estimate the mitigation potential for the timeframe of 2010–2050 using the principles of Low Carbon Society (LCS). In addition, the paper would also evaluate emission tax as a key driver of Greenhouse Gas (GHG) mitigation along with Marginal Abatement Cost (MAC) analysis. Another secondary objective is to analyse the impact of mitigation on energy security of the industrial sector. The Thai industrial sector was modelled using AIM/Enduse model, which is a recursive dynamic optimisation model belonging to the Asia–Pacific Integrated Model (AIM) family. Thai industrial sector was divided into nine sub-sectors based on national economic reporting procedures. Results suggest that the mitigation potential in 2050, compared to the Baseline scenario, is around 20% with positive impacts on energy security. The Baseline emission will approximately be 377 Mt-CO 2 in the industrial sector. All four indicators of energy security, Primary Energy Intensity, Carbon Intensity, Oil

  13. Facilitating Low-Carbon Living? A Comparison of Intervention Measures in Different Community-Based Initiatives

    Directory of Open Access Journals (Sweden)

    Martina Schäfer

    2018-04-01

    Full Text Available The challenge of facilitating a shift towards sustainable housing, food and mobility has been taken up by diverse community-based initiatives ranging from “top-down” approaches in low-carbon municipalities to “bottom-up” approaches in intentional communities. This paper compares intervention measures in four case study areas belonging to these two types, focusing on their potential of re-configuring daily housing, food, and mobility practices. Taking up critics on dominant intervention framings of diffusing low-carbon technical innovations and changing individual behavior, we draw on social practice theory for the empirical analysis of four case studies. Framing interventions in relation to re-configuring daily practices, the paper reveals differences and weaknesses of current low-carbon measures of community-based initiatives in Germany and Austria. Low-carbon municipalities mainly focus on introducing technologies and offering additional infrastructure and information to promote low-carbon practices. They avoid interfering into residents’ daily lives and do not restrict carbon-intensive practices. In contrast, intentional communities base their interventions on the collective creation of shared visions, decisions, and rules and thus provide social and material structures, which foster everyday low-carbon practices and discourage carbon-intensive ones. The paper discusses the relevance of organizational and governance structures for implementing different types of low-carbon measures and points to opportunities for broadening current policy strategies.

  14. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation

    Science.gov (United States)

    Chen, Quan; Tsai, Sang-Bing; Zhou, Jie; Yu, Jian; Chang, Li-Chung; Li, Guodong; Zheng, Yuxiang; Wang, Jiangtao

    2018-01-01

    Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees’ low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees’ job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice. PMID:29301375

  15. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Quan Chen

    2018-01-01

    Full Text Available Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees’ low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees’ job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice.

  16. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation.

    Science.gov (United States)

    Chen, Quan; Tsai, Sang-Bing; Zhai, Yuming; Zhou, Jie; Yu, Jian; Chang, Li-Chung; Li, Guodong; Zheng, Yuxiang; Wang, Jiangtao

    2018-01-03

    Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees' low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees' job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice.

  17. Building low carbon communities in China: The role of individual’s behaviour change and engagement

    International Nuclear Information System (INIS)

    Jiang, Ping; Chen, Yihui; Xu, Bin; Dong, Wenbo; Kennedy, Erin

    2013-01-01

    Low carbon sustainability has been addressed in China’s national development strategies. This research explores individual behaviour change and engagement in building low carbon communities in China through a case study looking at the building of a low carbon campus at Fudan University, Shanghai. Individual behaviour directly influences the overall energy consumption and carbon emissions on Fudan University’s campus. Even though relevant polices have been issued for energy conservation, the energy consumption increased by 5% every year, which suggests that the “top-down” approach telling students and staff “what to do” does not work effectively. Based on a comprehensive method which includes the individual and social aspects related to the energy behaviour, the research analyses the promotion of individual engagement in building a low carbon campus through behaviour change based on four main aspects: (1) awareness raising and behaviour forming; (2) approaches to encourage behaviour change; (3) beyond the barriers and the constraints; and (4) systems and mechanisms for the long-term engagement. A low carbon management system is proposed for not only addressing management and technical solutions at the university level, but also based on the contributions from behaviour changes in establishing a low carbon campus at Fudan University at the individual level. - Highlights: • The “top-down” approach is not an effective way to building low carbon communities in China. • Individuals’ behaviour change and engagement play a key role in low carbon sustainability. • Awareness raising, proper approaches and sound mechanisms are necessary to encourage long-term behaviour changes. • An integrated management system is developed for comprehensibly establishing a low carbon campus at Fudan University

  18. A low carbon industrial revolution? Insights and challenges from past technological and economic transformations

    International Nuclear Information System (INIS)

    Pearson, Peter J.G.; Foxon, Timothy J.

    2012-01-01

    Recent efforts to promote a transition to a low carbon economy have been influenced by suggestions that a low carbon transition offers challenges and might yield economic benefits comparable to those of the previous industrial revolutions. This paper examines these arguments and the challenges facing a low carbon transition, by drawing on recent thinking on the technological, economic and institutional factors that enabled and sustained the first (British) industrial revolution, and the role of ‘general purpose technologies’ in stimulating and sustaining this and subsequent industrial transformation processes that have contributed to significant macroeconomic gains. These revolutions involved profound, long drawn-out changes in economy, technology and society; and although their energy transitions led to long-run economic benefits, they took many decades to develop. To reap significant long-run economic benefits from a low carbon transition sooner rather than later would require systemic efforts and incentives for low carbon innovation and substitution of high-carbon technologies. We conclude that while achieving a low carbon transition may require societal changes on a scale comparable with those of previous industrial revolutions, this transition does not yet resemble previous industrial revolutions. A successful low carbon transition would, however, amount to a different kind of industrial revolution. - Highlights: ► Investigates lessons for a low carbon transition from past industrial revolutions. ► Explores the implications of ‘general purpose technologies’ and their properties. ► Examines analysis of ‘long waves’ of technological progress and diffusion. ► Draws insights for low carbon transitions and policy.

  19. Evaluation criteria of structural steel reliability

    International Nuclear Information System (INIS)

    Zav'yalov, A.S.

    1980-01-01

    Different low-carbon and medium-carbon structural steels are investigated. It is stated that steel reliability evaluation criteria depend on the fracture mode, steel suffering from the brittle fracture under the influence of the stresses (despite their great variety) arising in articles during the production and operation. Fibrous steel fracture at the given temperature and article thickness says about its high ductility and toughness and brittle fractures are impossible. Brittle fractures take place in case of a crystalline and mixed fracture with a predominant crystalline component. Evaluation methods of article and sample steel structural strength differing greatly from real articles in a thickness (diameter) or used at temperatures higher than possible operation temperatures cannot be reliability evaluation criteria because at a great thickness (diameter) and lower operation temperatures steel fracture and its strain mode can change resulting in a sharp reliability degradation

  20. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  1. Iceland as a demonstrator for a transition to low carbon economy?

    Science.gov (United States)

    Asbjornsson, Einar Jon; Stefansson, Hlynur; Finger, David Christian

    2017-04-01

    The energy supply in Iceland is quite unique, about 85% of the total primary energy is coming from renewable resources. Nevertheless, the ecological footprint of an average Icelander is with 6.5 worlds, one of the highest worldwide and the energy consumption per capita is about 7 times higher than the European average. Recent developments have shown that there is a great potential to reduce the footprint and develop towards low carbon economy. With its small population, well educated and governed society and clear system boundaries to the outside world, Iceland is a good research laboratory and an ideal demonstrator for a transition towards a low carbon economy. This presentation will outline how several innovative research projects at Reykjavik University could lead Iceland towards a sustainable and low carbon economy. The presentations will conclude with a visionary outlook how Iceland can become a demonstration nation towards a prosperous, low carbon and sustainable economy, helping stabilize global warming at an acceptable level.

  2. Scenarios for low carbon and low water electric power plant operations: implications for upstream water use

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset includes all data used in the creation of figures and graphs in the paper: "Scenarios for low carbon and low water electric power plant operations:...

  3. Low carbon thermal technologies in an ageing society – What are the issues?

    International Nuclear Information System (INIS)

    Day, Rosie

    2015-01-01

    This paper is a commentary on the theme of this special issue, low carbon thermal technologies and older age, and the Conditioning Demand project. Drawing on the project findings, I discuss some key aspects of ageing that are relevant to the roll-out of low carbon technologies in domestic settings in ageing, developed societies. These include biological, cognitive, institutional and social dimensions. I conclude with some suggestions for ways of working to maximise the potential benefits of low carbon thermal technologies for older people. -- Highlights: •The specific needs of older people must be considered in low carbon transitions. •The vulnerability discourse however dominates in a way which is unhelpful. •Some physiological aspects of ageing affect person-technology fit. •Cultural aspects influence the success of integration of LCTs into domestic settings. •More inclusive design is needed if older people are to benefit from LCTs

  4. Trading scheme 'key' to low-carbon economy

    International Nuclear Information System (INIS)

    2006-01-01

    Federal Opposition Leader Kim Beazley has emphasised the importance of getting the economics of environmental policy right by introducing market-based mechanisms for pricing emissions. 'Market-based mechanisms such as emissions trading are central to moving to a low-carbon economy,' he said in his latest blueprint. 'A functioning carbon market will deliver a price signal, so there is a long-term incentive to cut emissions further, and a mechanism for trading, so that energy can be allocated efficiently in the economy. It will also encourage greater private investment in clean energy technology.' Mr Beazley said the new market would also reward the many companies who were already adapting to a carbon-constrained world. 'This includes those global companies in Australia that already operate in emissions trading markets overseas. An effective price signal for carbon in Australia will allow these companies to benefit directly from their good corporate citizenship and long-term vision.' Mr Beazley has committed a federal Labor government to work with state governments and business to establish the national trading scheme. He also criticised the Federal Government for refusing to ratify the Kyoto Protocol, which he argued excluded Australian businesses from participating in the emerging global carbon trade. This made it harder for businesses to break into the market for cleaner production technologies overseas. While again admitting Kyoto was not perfect, Mr Beazley said ratification would see Australia part of what would potentially be 'the biggest market in the world by 2020'. He said the recent Asia Pacific Climate Change Pact was a positive step but was not an alternative to Kyoto. 'Above all, it has no economic mechanisms to drive further change. 'Without ratifying Kyoto some of our businesses are missing out on effective participation in international schemes that offer substantial financial rewards for greenhouse gas reductions. 'By ratifying Kyoto and adopting

  5. Process Reengineering of Cold Chain Logistics of Agricultural Products Based on Low-carbon Economy

    OpenAIRE

    Guo, Hong-xia; Shao, Ming

    2012-01-01

    Through the process analysis of cold chain logistics of agricultural products, we find that cold chain logistics of agricultural products contradict the development model of low-carbon economy to some extent. We apply the development idea of low-carbon economy, introduce the third-party logistics companies, establish distribution center of cold chain logistics of agricultural products, and strengthen information sharing, to reengineer the process of cold chain logistics of agricultural produc...

  6. Low-carbon building assessment and multi-scale input-output analysis

    Science.gov (United States)

    Chen, G. Q.; Chen, H.; Chen, Z. M.; Zhang, Bo; Shao, L.; Guo, S.; Zhou, S. Y.; Jiang, M. M.

    2011-01-01

    Presented as a low-carbon building evaluation framework in this paper are detailed carbon emission account procedures for the life cycle of buildings in terms of nine stages as building construction, fitment, outdoor facility construction, transportation, operation, waste treatment, property management, demolition, and disposal for buildings, supported by integrated carbon intensity databases based on multi-scale input-output analysis, essential for low-carbon planning, procurement and supply chain design, and logistics management.

  7. Win-win strategies in directing low-carbon resilient development path

    International Nuclear Information System (INIS)

    Masui, Toshihiko; Kainuma, Mikiko

    2015-01-01

    This section explores big win-win strategies in directing low carbon resilient development path. There are lots of “leapfrog” development possibilities in developing countries, which go directly from a status of under-development through to efficient and environmentally benign lifestyle. To achieve low carbon resilient paths, not only technology development but also institutional and behavioral changes are required. Science-policy nexus is also discussed.

  8. Possible Role of NPP in Long Term Low Carbon Development Strategy - Case Study Croatia

    International Nuclear Information System (INIS)

    Tomsic, Z.; Rajsl, I.; Filipovic, M.

    2016-01-01

    The term low - carbon development strategies (LEDS) was developed on the UN Framework Convention on Climate Change (UNFCCC) in 2008. LEDS used to describe a long-term national economic development plans or strategies that include low emissions and economic growth resistant to climate change. The concept of Low Carbon Development Strategies (LCDS) has been introduced by the Conference of Parties to the UNFCCC as a common but differentiated approach to meet the overall emissions reduction objectives: 'All countries shall prepare Low Emission Development Strategies - nationally-driven and represent[ing] the aims and objectives of individual Parties in accordance with national circumstances and capacities' (Cancun Agreement). Low Carbon Development Strategies (LCDS) in this way become an overarching framework to design and achieve Nationally Appropriate Mitigation Actions (NAMAs) reflecting the Common but Differentiated Responsibilities (CBDR) of all countries. For Long-Term National Strategy and Action Plan for Low-Carbon Development the main objective of this programme is the development of a long-term national strategy and action plan for low-carbon development to enable country to fulfil its commitment to carbon obligations. Low-carbon development strategy will become the fundamental for the development of the energy with low rate of carbon, but also for the entire economy. European Union is the leader in the effort to reduce emissions especially in the energy sector as the sector with the highest rate of emission. With the goal of reducing emissions, necessary measures are accentuated for energy in the EU Countries, as well as in Croatia. It will be presented the possibilities for realization of Croatian low-carbon development and particularly possible role and barriers for Nuclear power plants for Low carbon emissions development in the electricity sector until 2050. (author).

  9. Optimal Coordination Strategy of Regional Vertical Emission Abatement Collaboration in a Low-Carbon Environment

    Directory of Open Access Journals (Sweden)

    Daming You

    2018-02-01

    Full Text Available This study introduces a time factor into a low-carbon context, and supposes the contamination control state of local government and the ability of polluting enterprise to abate emissions as linear increasing functions in a regional low-carbon emission abatement cooperation chain. The local government effectuates and upholds the low-carbon development within the jurisdiction that is primarily seeking to transform regional economic development modes, while the polluting enterprise abates the amounts of emitted carbon in the entire period of product through simplifying production, facilitating decontamination, and adopting production technology, thus leading to less contamination. On that basis, we infer that the coordinated joint carbon reduction model and two decentralization contracts expound the dynamic coordination strategy for a regional cooperation chain in terms of vertical carbon abatement. Furthermore, feedback equilibrium strategies that are concerned with several diverse conditions are compared and analyzed. The main results show that a collaborative centralized contract is able to promote the regional low-carbon cooperation chain in order to achieve a win–win situation in both economic and environmental performance. Additionally, the optimal profits of the entire regional low-carbon cooperation channel under an integration scenario evidently outstrip that of two non-collaborative decentralization schemes. Eventually, the validity of the conclusions is verified with a case description and numerical simulation, and the sensitivity of the relevant parameters is analyzed in order to lay a theoretical foundation and thus facilitate the sustainable development of a regional low-carbon environment.

  10. Geographies of energy transition: Space, place and the low-carbon economy

    International Nuclear Information System (INIS)

    Bridge, Gavin; Bouzarovski, Stefan; Bradshaw, Michael; Eyre, Nick

    2013-01-01

    This paper makes a case for examining energy transition as a geographical process, involving the reconfiguration of current patterns and scales of economic and social activity. The paper draws on a seminar series on the ‘Geographies of Energy Transition: security, climate, governance' hosted by the authors between 2009 and 2011, which initiated a dialogue between energy studies and the discipline of human geography. Focussing on the UK Government's policy for a low carbon transition, the paper provides a conceptual language with which to describe and assess the geographical implications of a transition towards low carbon energy. Six concepts are introduced and explained: location, landscape, territoriality, spatial differentiation, scaling, and spatial embeddedness. Examples illustrate how the geographies of a future low-carbon economy are not yet determined and that a range of divergent – and contending – potential geographical futures are in play. More attention to the spaces and places that transition to a low-carbon economy will produce can help better understand what living in a low-carbon economy will be like. It also provides a way to help evaluate the choices and pathways available. - Highlights: ► Examines transition as a geographical process, reconfiguring patterns and scales of activity. ► Provides concepts for assessing geographical implications of transition to a low-carbon economy. ► Outlines location, landscape, territoriality, uneven development, scaling, and embeddedness.

  11. Quantitative Study on the Dynamic Mechanism of Smart Low-Carbon City Development in China

    Directory of Open Access Journals (Sweden)

    Bo Pang

    2016-05-01

    Full Text Available With the development of new generation technology and the low-carbon economy, the smart low-carbon city has become one of the academic hotspots. Many studies on it have begun; however, the dynamic mechanism is rarely involved. Therefore, this paper uses the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS method to creatively take a quantitative study on a Chinese smart low-carbon city’s dynamic mechanism. The results show that: (1 the three main dynamics of smart low-carbon city development in China are institutional and cultural conditions, facilities and functions conditions and economy and industry conditions, but the overall utility is relatively low; (2 the level of the dynamic operation mechanism of the Chinese smart low-carbon city is distinct between regions, indicating a diminishing spatial law from east to west and differences within regions; (3 the imbalance of the comprehensive dynamic mechanism and the operation status between smart low-carbon cities is prominent, showing a decreasing urban scale law of from big to small and differences within each scale, and a descending administration hierarchy law from high to low and differences within each class; (4 seven basic development patterns can be obtained, and most of the cities belong to the external strong/internal weak mode, which basically matches with its development realities. Finally, general policy recommendations and countermeasures of optimization and improvement are proposed.

  12. Approach and practices of district energy planning to achieve low carbon outcomes in China

    International Nuclear Information System (INIS)

    Xu, Baoping; Zhou, Shaoxiang; Hao, Lin

    2015-01-01

    District energy planning is an important methodology to assist in realizing a lower carbon target. However, district energy planning has not yet been incorporated into the statutory planning system in China, primarily because there are no clear standards and specifications for these plans. In this paper, we propose a general framework and low carbon estimation method for district energy planning, which is based on evaluating the low carbon energy planning practices of several new districts in China. In addition, several key points of concern in the planning process are extracted and discussed: overall infrastructure planning; co-operation between city planning and other special low carbon eco-planning; investment, financing and profitable operation; planning management mechanisms; and the management of the construction of the energy system to coincide with the project schedule. We carried out a case study of a low carbon energy plan for a new district of Beijing to evaluate our framework. Finally, we conclude that to realize the low carbon target, regional energy planning covering technologies, the market and management should be standardized as soon as possible. -- Highlights: •A general framework for district energy planning is proposed. •A case study of a low carbon energy plan for a new district is carried out. •District energy planning should be standardized as soon as possible. •The most suitable spatial scale for energy planning is at the municipal level

  13. Optimal Strategies for Low Carbon Supply Chain with Strategic Customer Behavior and Green Technology Investment

    Directory of Open Access Journals (Sweden)

    Wen Jiang

    2016-01-01

    Full Text Available Climate change is mainly caused by excessive emissions of carbon dioxide and other greenhouse gases. In order to reduce carbon emissions, cap and trade policy is implemented by governments in many countries, which has significant impacts on the decisions of companies at all levels of the low carbon supply chain. This paper investigates the decision-making and coordination of a low carbon supply chain consisting of a low carbon manufacturer who produces one product and is allowed to invest in green technology to reduce carbon emissions in production and a retailer who faces stochastic demands formed by homogeneous strategic customers. We investigate the optimal production, pricing, carbon trading, and green technology investment strategies of the low carbon supply chain in centralized (including Rational Expected Equilibrium scenario and quantity commitment scenario and decentralized settings. It is demonstrated that quantity commitment strategy can improve the profit of the low carbon supply chain with strategic customer behavior. We also show that the performance of decentralized supply chain is lower than that of quantity commitment scenario. We prove that the low carbon supply chain cannot be coordinated by revenue sharing contract but by revenue sharing-cost sharing contract.

  14. Climate consequences of low-carbon fuels: The United States Renewable Fuel Standard

    International Nuclear Information System (INIS)

    Hill, Jason; Tajibaeva, Liaila; Polasky, Stephen

    2016-01-01

    A common strategy for reducing greenhouse gas (GHG) emissions from energy use is to increase the supply of low-carbon alternatives. However, increasing supply tends to lower energy prices, which encourages additional fuel consumption. This “fuel market rebound effect” can undermine climate change mitigation strategies, even to the point where efforts to reduce GHG emissions by increasing the supply of low-carbon fuels may actually result in increased GHG emissions. Here, we explore how policies that encourage the production of low-carbon fuels may result in increased GHG emissions because the resulting increase in energy use overwhelms the benefits of reduced carbon intensity. We describe how climate change mitigation strategies should follow a simple rule: a low-carbon fuel with a carbon intensity of X% that of a fossil fuel must displace at least X% of that fossil fuel to reduce overall GHG emissions. We apply this rule to the United States Renewable Fuel Standard (RFS2). We show that absent consideration of the fuel market rebound effect, RFS2 appears to reduce GHG emissions, but once the fuel market rebound effect is factored in, RFS2 actually increases GHG emissions when all fuel GHG intensity targets are met. - Highlights: • Low-carbon fuels partially displace petroleum via fuel market rebound effect. • Synthesis of recent analyses shows incomplete petroleum displacement by biofuels. • Fuel market rebound effect can reduce or reverse climate benefit of low-carbon fuels. • Fossil fuel displacement must exceed relative carbon footprint of a low-carbon fuel. • The Renewable Fuel Standard increases greenhouse gas emissions when mandate is met.

  15. Key policy considerations for facilitating low carbon technology transfer to developing countries

    International Nuclear Information System (INIS)

    Ockwell, David G.; Watson, Jim; MacKerron, Gordon; Pal, Prosanto; Yamin, Farhana

    2008-01-01

    Based on Phase I of a UK-India collaborative study, this paper analyses two case studies of low carbon technologies-hybrid vehicles and coal-fired power generation via integrated gasification combined cycle (IGCC). The analysis highlights the following six key considerations for the development of policy aimed at facilitating low carbon technology transfer to developing countries: (1) technology transfer needs to be seen as part of a broader process of sustained, low carbon technological capacity development in recipient countries; (2) the fact that low carbon technologies are at different stages of development means that low carbon technology transfer involves both vertical transfer (the transfer of technologies from the R and D stage through to commercialisation) and horizontal transfer (the transfer from one geographical location to another). Barriers to transfer and appropriate policy responses often vary according to the stage of technology development as well as the specific source and recipient country contexts; (3) less integrated technology transfer arrangements, involving, for example, acquisition of different items of plant from a range of host country equipment manufacturers, are more likely to involve knowledge exchange and diffusion through recipient country economies; (4) recipient firms that, as part of the transfer process, strategically aim to obtain technological know-how and knowledge necessary for innovation during the transfer process are more likely to be able to develop their capacity as a result; (5) whilst access to Intellectual Property Rights (IPRs) may sometimes be a necessary part of facilitating technology transfer, it is not likely to be sufficient in itself. Other factors such as absorptive capacity and risks associated with new technologies must also be addressed; (6) there is a central role for both national and international policy interventions in achieving low carbon technology transfer. The lack of available empirical analysis

  16. Past performance and future needs for low carbon climate resilient infrastructure– An investment perspective

    International Nuclear Information System (INIS)

    Kennedy, Christopher; Corfee-Morlot, Jan

    2013-01-01

    This article explores the investment implications of moving to low-carbon, climate-resilient infrastructure. It begins with analysis of gross fixed capital formation and decarbonisation trends to examine past performance of OECD countries in reducing GHG emissions from 1997 to 2007. Many OECD countries made progress in decoupling GHG emissions from infrastructure investment in residential buildings, and to a lesser extent from power and industry, but increased efforts are required, especially in the transportation sector. The analysis highlights the need to accelerate the pace and scale of change to reverse GHG emission trends to bring into reach ambitious climate policy goals. It then assesses future global infrastructure needs under low-carbon and business-as-usual (BAU) global warming scenarios, and the incremental costs of going “low-carbon” are estimated to be small relative to the magnitude of the BAU infrastructure investment needs. Global infrastructure needs for 2015–2020, including buildings and transportation vehicles, are approximately 6.7 trillion USD/year under BAU. Incremental costs of low-carbon infrastructure are of the order −70 to +450 billion USD/year. Achieving climate resilient infrastructure may add costs, but there is potentially synergistic overlap with low-carbon attributes. Although estimates are incomplete, the technical and financial inter-dependency between infrastructure systems suggests the potential to generate infrastructure investment to support a “virtuous cycle” of low-carbon growth. - Highlights: • Conceptualisation of interactions between low carbon and climate resilient infrastructure (Fig. 1). • New performance measures of national GHG emissions vs. capital formation (Section 2). • Comparion of global infrastructure costs under low and high carbon scenarios (Table 1). • Understanding of infrastructures that support virtuous cycles of low carbon growth (Fig. 8)

  17. Public financial institutions and the low carbon transition: five case studies on low-carbon infrastructure and project investment. Environment working paper No. 72:

    International Nuclear Information System (INIS)

    Cochran, Ian; Hubert, Romain; Marchal, Virginie; Youngman, Robert; Rus, Katerina; Baker, Jade; Kynaston, Jane

    2014-01-01

    Public financial institutions (PFIs) are well-positioned to act as a key leverage point for governments' efforts to mobilise private investment in low-carbon projects and infrastructure. The study identifies the tools, instruments and approaches used by five PFIs to directly support and scale-up domestic private sector investment in sustainable transport, energy-efficiency and renewable energy in OECD countries. Between 2010-2012, these five institutions - Group Caisse des Depots in France, KfW Bankengruppe in Germany, the UK Green Investment Bank, the European Investment Bank, and the European Bank for Reconstruction and Development - have provided over 100 billion euros of equity investment and financing for energy efficiency, renewable energy and sustainable transport projects. They use both traditional and innovative approaches to link low-carbon projects with finance through enhancing access to capital; facilitating risk reduction and sharing; improving the capacity of market actors; and shaping broader market practices and conditions. (authors)

  18. Benefits of Low Carbon Development Strategies in Emerging Cities of Developing Country: a Case of Kathmandu

    Directory of Open Access Journals (Sweden)

    Shree Raj Shakya

    2016-06-01

    Full Text Available Kathmandu is one of the fastest growing cities in South Asia facing various challenges related to climate change, local pollutants emissions and energy security of supply. This study analysed the greenhouse gas mitigation potential in different economic sectors of the city by using Long-range Energy Planning (LEAP frame work. It shows that the effect of implementing various low carbon development strategy options can reduce 35.2% of total greenhouse gas emission from energy use as compared to the base case scenario in 2030. This indicates the need for exploring the possibility of utilizing the global climate funds and adopting voluntary mechanisms for greenhouse gas mitigation. The estimated demand side technology investment cost of low carbon measures for different sectors ranges from less than US$ 1/tonne CO2e for residential sector to US$ 99/tonne CO2e for transport sector. The low carbon options also results co-benefits in terms of significant reduction in emission of local pollutants and improvement of energy security. As Government of Nepal has envisioned following low carbon economic development path on the long run, there is the need of establishment of regulatory framework, institutional framework and development of clear action plans for realizing the implementation of low carbon development strategy measures in the country.

  19. Comprehensive evaluation on low-carbon development of coal enterprise groups.

    Science.gov (United States)

    Wang, Bang-Jun; Wu, Yan-Fang; Zhao, Jia-Lu

    2017-12-19

    Scientifically evaluating the level of low-carbon development in terms of theoretical and practical significance is extremely important to coal enterprise groups for implementing national energy-related systems. This assessment can assist in building institutional mechanisms that are conducive for the economic development of coal business cycle and energy conservation as well as promoting the healthy development of coal enterprises to realize coal scientific development and resource utilization. First, by adopting systematic analysis method, this study builds low-carbon development evaluation index system for coal enterprise groups. Second, to determine the weight serving as guideline and criteria of the index, analytic hierarchy process (AHP) is applied using integrated linear weighted sum method to evaluate the level of low-carbon development of coal enterprise groups. Evaluation is also performed by coal enterprise groups, and the process comprises field analysis and evaluation. Finally, industrial policies are proposed regarding the development of low-carbon coal conglomerate strategies and measures. This study aims mainly to guide the low-carbon development of coal enterprise groups, solve the problem of coal mining and the destruction of ecological environment, support the conservation of raw materials and various resources, and achieve the sustainable development of the coal industry.

  20. Evolutionary pattern, operation mechanism and policy orientation of low carbon economy development

    Directory of Open Access Journals (Sweden)

    X. Dou

    2016-10-01

    Full Text Available The essence of low carbon economy development is a continuous evolution and innovation process of socio-economic system from traditional high carbon economy to new sustainable green low carbon economy to achieve a sustainable dynamic balance and benign interactive development of various elements between society, economy and natural ecosystem. At the current stage, China’s socio-economy is showing the feature of "three high" (high energy consumption, high emissions and high pollution. In this case, quickly to promote the development of green low carbon economy is necessary and urgent. This research indicates that, low carbon economy development is achieved by micro-economic agents such as households, businesses and social intermediary organizations through Government’s guidance and the role of market mechanism. In low carbon economy development, the state (government is a leader and markets are core, while economic agents (e.g., households, businesses and social intermediary organizations are basis. For this reason, it is necessary to build an effective cleaner development and incentive-compatible policy system oriented to end-users.

  1. Ultrafine grained steels processed by equal channel angular pressing

    International Nuclear Information System (INIS)

    Shin, Dong Hyuk; Park, Kyung-Tae

    2005-01-01

    Recent development of ultrafine grained (UFG) low carbon steels by using equal channel angular pressing (ECAP) and their room temperature tensile properties are reviewed, focusing on the strategies overcoming their inherent mechanical drawbacks. In addition to ferrite grain refinement, when proper post heat treatments are imposed, carbon atom dissolution from pearlitic cementite during ECAP can be utilized for microstructural modification such as uniform distribution of nano-sized cementite particles or microalloying element carbides inside UFG ferrite grains and fabrication of UFG ferrite/martensite dual phase steel. The utilization of nano-sized particles is effective on improving thermal stability of UFG low carbon ferrite/pearlite steel but less effective on improving its tensile properties. By contrast, UFG ferrite/martensite dual phase steel exhibits an excellent combination of ultrahigh strength, large uniform elongation and extensive strain hardenability

  2. Operation management for a low-carbon economy: a literature review on stakeholders, barriers and motivations

    Directory of Open Access Journals (Sweden)

    Daniela Andriani Ribeiro

    2017-03-01

    Full Text Available The aim of this study is to identify stakeholders acting as barriers and/or motivations for the adoption of low- -carbon operation management practices through the lens of the stakeholder theory. Stakeholders have a strong influence on companies to adopt environmental practices due to the climate change context and its consequences on the economic, environmental and social scenario. Thus, this study conducts a literature review in the Scopus database with searches that relate stakeholder theory and low-carbon practices to identify stakeholders. As a result, Customers and Government are the most active stakeholders as drivers or barriers to the adoption of environmental practices. Therefore, it is important to understand the different attributes of each stakeholder and their demands in order to trace hierarchy strategies of adopting any low-carbon operation management practices and creating mechanisms of collaboration with those stakeholders who drive the adoption of those practices.

  3. Simulation and Optimization of One Live Pig Low-Carbon Industry Chain Using SD-RCCM

    Directory of Open Access Journals (Sweden)

    Jiuping Xu

    2013-01-01

    Full Text Available The destruction of the natural environment has been drawing more and more attention. Developing low-carbon industry chains is an effective solution to the conflict between rapid economic growth and high CO2 emissions. Summarizing various traditional and new industry chain sustainable development, live pig industry was chosen as a typical industry chain to study low-carbon development using a system dynamics and random chance-constrained model (SD-RCCM. Leshan, a world natural and cultural heritage area in China, was selected as a typical city to analyze the low-carbon pig industry. Three different programs based on distribution ratios were selected to study this industry. The results showed that program 1, which considers both environmental and economic benefits, realizes sustainable development. In order to extend the pig industry chain and fully utilize pig ordure and other waste, introducing a Clean Development Mechanism (CDM and household biogas exploitation program is recommended.

  4. The Impact of Transport Mode and Carbon Policy on Low-Carbon Retailer

    Directory of Open Access Journals (Sweden)

    Yi Zheng

    2015-01-01

    Full Text Available Low-carbon retail has become a strategic target for many developed and developing economies. This study discusses the impact of transport mode and carbon policy on achieving this objective. We investigated the retailer transportation mode, pricing, and ordering strategy, which all consider carbon-sensitive demand under the carbon cap-and-trade policy. We analyzed the optimal decision of retailer and their maximum profit affected by transport mode and cap-and-trade policy parameters. Results show that the two elements (cap-and-trade policy and consumer low-carbon awareness could encourage the retailer to choose low-carbon transportation. The two elements also influence the profit and optimal decision of retailer. Finally, a numerical example is presented to illustrate the applicability of the model.

  5. Low carbon Finland 2050. VTT clean energy technology strategies for society

    Energy Technology Data Exchange (ETDEWEB)

    Koljonen, T.; Simila, L.; Sipila, K. [and others

    2012-11-15

    The Low Carbon Finland 2050 project by VTT Technical Research Centre of Finland aims to assess the technological opportunities and challenges involved in reducing Finland's greenhouse gas emissions. A target for reduction is set as at least 80% from the 1990 level by 2050 as part of an international effort, which requires strong RD and D in clean energy technologies. Key findings of the project are presented in this publication, which aims to stimulate enlightening and multidisciplinary discussions on low-carbon futures for Finland. The project gathered together VTT's technology experts in clean energy production, smart energy infrastructures, transport, buildings, and industrial systems as well as experts in energy system modelling and foresight. VTT's leading edge 'Low Carbon and Smart Energy' enables new solutions with a demonstration that is the first of its kind in Finland, and the introduction of new energy technology onto national and global markets. (orig.)

  6. Low carbon Finland 2050. VTT clean energy technology strategies for society

    Energy Technology Data Exchange (ETDEWEB)

    Koljonen, T; Simila, L; Sipila, K [and others

    2012-11-15

    The Low Carbon Finland 2050 project by VTT Technical Research Centre of Finland aims to assess the technological opportunities and challenges involved in reducing Finland's greenhouse gas emissions. A target for reduction is set as at least 80% from the 1990 level by 2050 as part of an international effort, which requires strong RD and D in clean energy technologies. Key findings of the project are presented in this publication, which aims to stimulate enlightening and multidisciplinary discussions on low-carbon futures for Finland. The project gathered together VTT's technology experts in clean energy production, smart energy infrastructures, transport, buildings, and industrial systems as well as experts in energy system modelling and foresight. VTT's leading edge 'Low Carbon and Smart Energy' enables new solutions with a demonstration that is the first of its kind in Finland, and the introduction of new energy technology onto national and global markets. (orig.)

  7. A Low-Carbon-Based Bilevel Optimization Model for Public Transit Network

    Directory of Open Access Journals (Sweden)

    Xu Sun

    2013-01-01

    Full Text Available To satisfy the demand of low-carbon transportation, this paper studies the optimization of public transit network based on the concept of low carbon. Taking travel time, operation cost, energy consumption, pollutant emission, and traffic efficiency as the optimization objectives, a bilevel model is proposed in order to maximize the benefits of both travelers and operators and minimize the environmental cost. Then the model is solved with the differential evolution (DE algorithm and applied to a real network of Baoji city. The results show that the model can not only ensure the benefits of travelers and operators, but can also reduce pollutant emission and energy consumption caused by the operations of buses, which reflects the concept of low carbon.

  8. Exploring the reducing role of boron: added insights from theory.

    Science.gov (United States)

    Dangat, Yuvraj; Vanka, Kumar

    2016-04-14

    Carbon-carbon coupling in CO molecules is a challenging proposition, and very few main group complexes have been shown to effect this process. A recently reported triply bonded diboryne system (1) is notable for coupling four CO molecules to produce a (bis)boralactone species. The current full quantum chemical computational investigation with density functional theory (DFT) provides important insights into the nature of the CO coupling process by triply bonded diboryne systems. The complete reaction pathway leading to the formation of the (bis)boralactone has been determined. Factors that make this system so successful in coupling CO groups have been elucidated, and pertinent issues, such as why the coupling process stops after four CO additions, have been explored. Also, importantly, insights have been gained through the natural bond orbital (NBO) analysis into how the back-donation from diboryne activates CO.

  9. PECULIARITIES OF FORMATION OF STRUCTURE AND PROPERTIES AT THERMO-MECHANICAL PROCESSING OF ROLLED WIRE OF NICKEL-MOLYBDENUM STEEL WITH WELDING FUNCTION

    OpenAIRE

    V. A. Lutsenko

    2012-01-01

    There are results of researches of the mechanical properties and structure of the wire rod made of low-carbon nickel molybdenum steel after reduction to toughness thermomechanical treatment in the stream of high-speed wire mill.

  10. A Study on Life Cycle CO2 Emissions of Low-Carbon Building in South Korea

    Directory of Open Access Journals (Sweden)

    Su-Hyun Cho

    2016-06-01

    Full Text Available There have been much interest and many efforts to control global warming and reduce greenhouse gas (GHG emissions throughout the world. Recently, the Republic of Korea has also increased its GHG reduction goal and searched for an implementation plan. In buildings, for example, there have been technology developments and deployment policies to reduce GHG emissions from a life cycle perspective, covering construction materials, building construction, use of buildings and waste disposal. In particular, Korea’s Green Standard for Energy and Environmental Design is a certification of environmentally-friendly buildings for their energy saving and reduction of environmental pollution throughout their lives. In fact, the demand and adoption of the certification are rising every year. In construction materials and buildings, as a result, an environmentally-friendly aspect has become crucial. The importance of construction material and building development technologies that can reduce environmental load by diminishing GHG emissions in buildings has emerged. Moreover, there has been a rising necessity to verify the GHG reduction effects of buildings. To assess the reduction of carbon emissions in the buildings built with low-carbon construction technologies and materials, therefore, this study estimated life cycle carbon emissions in reference buildings in which general construction materials are used and in low-carbon buildings. For this, the carbon emissions and their reduction from construction materials (especially concrete between conventional products and low-carbon materials were estimated, using Life Cycle Assessment (LCA. After estimating carbon emissions from a building life cycle perspective, their reduction in low-carbon buildings compared to the reference buildings was reviewed. The results found that compared to conventional buildings, low-carbon buildings revealed a 25% decrease in carbon emissions in terms of the reduction of Life Cycle

  11. Low-Carbon Transportation Oriented Urban Spatial Structure: Theory, Model and Case Study

    Directory of Open Access Journals (Sweden)

    Yuyao Ye

    2017-12-01

    Full Text Available Optimising the spatial structure of cities to promote low-carbon travel is a primary goal of urban planning and construction innovation in the low-carbon era. There is a need for basic research on the structural characteristics that help to reduce motor traffic, thereby promoting energy conservation. We first review the existing literature on the influence of urban spatial structure on transport carbon dioxide emissions and summarise the influence mechanisms. We then present two low-carbon transportation oriented patterns of urban spatial structure including the traditional walking city and the modern transit metropolis, illustrated by case studies. Furthermore, we propose an improved model Green Transportation System Oriented Development (GTOD, which is an extension of traditional transit-oriented development (TOD and includes the additional features of a walking city and an emphasis on the integration of land use with a green transportation system, consisting of the public transportation and non-auto travel system. A compact urban form, effective mix of land use and appropriate scale of block are the basic structural features of a low-carbon transportation city. However, these features are only effective at promoting low-carbon transportation when integrated with the green traffic systems. Proper integration of the urban structural system with the green space system is also required. The optimal land use/transportation integration strategy is to divide traffic corridors with wedge-shaped green spaces and limit development along the transit corridors. This strategy forms the basis of the proposed urban structural model to promote low-carbon transportation and sustainable urban growth management.

  12. A qualitative and quantitative design of low-carbon development in Cambodia: Energy policy

    International Nuclear Information System (INIS)

    Hak, Mao; Matsuoka, Yuzuru; Gomi, Kei

    2017-01-01

    The formulation of a policy for a low-carbon development plan is one of the most important steps to help Cambodia achieve sustainable development objectives, promote a greener development path, and contribute to the global effort to reducing CO 2 emissions. This study is designed to propose some low-carbon energy strategies and quantitatively to assess CO 2 emissions and reductions. The Extended Snapshot (ExSS) tool is used to quantify socioeconomic assumptions and to estimate CO 2 emissions and reduction potentials. The results show that CO 2 emissions are projected to increase to about 23,277 (by about 5.5 times) and 91,325 ktCO 2 /year (by about 21.6 times) in 2030BaU and 2050BaU, respectively, from 4,221 ktCO 2 /year in 2010. This study proposes five strategies for low-carbon development plan towards 2050 which are expected to reduce CO 2 emissions by about 12,826 (about 55%) and 52,153 ktCO 2 /year (about 57%) in 2030CM and 2050CM, respectively. The present results should help researchers and experts gain a better understanding of CO 2 emissions and reduction potentials by applying a number of low-carbon measures in Cambodia. While the results should be counted as a preliminary study because of limited available country information, they are expected to provide useful insights for the government in formulating a concrete climate change mitigation policy for the country. - Highlights: • Low-carbon development is a win-win approach for socioeconomic development. • Cambodia has significant opportunities to reduce CO 2 emissions in the energy sector. • Five low-carbon energy strategies can limit CO 2 emissions by around 50% in Cambodia. • Green transport strategy contributes the highest CO 2 emissions reduction.

  13. Study on China's low carbon development in an Economy-Energy-Electricity-Environment framework

    International Nuclear Information System (INIS)

    Hu Zhaoguang; Yuan Jiahai; Hu Zheng

    2011-01-01

    Emissions mitigation is a major challenge for China's sustainable development. We summarize China's successful experiences on energy efficiency in past 30 years as the contributions of Energy Usage Management and Integrated Resource Strategic Planning, which are essential for low-carbon economy. In an Economy-Energy-Electricity-Environment (E4) framework, the paper studies the low-carbon development of China and gives an outlook of China's economy growth, energy-electricity demand, renewable power generation and energy conservation and emissions mitigation until 2030. A business-as-usual scenario is projected as baseline for comparison while low carbon energy and electricity development path is studied. It is defined as low carbon energy/electricity when an economy body manages to realize its potential economic growth fueled by less energy/electricity consumption, which can be characterized by indexes of energy/electricity intensity and emissions per-unit of energy consumption (electricity generation). Results show that, with EUM, China, could save energy by 4.38 billion ton oil equivalences (toes) and reduce CO 2 emission by 16.55 billion tons; with IRSP, China, could save energy by 1.5 Btoes and reduce CO 2 emission by 5.7 Btons, during 2010-2030. To realize the massive potential, China has to reshape its economic structure and rely much on technology innovation in the future. - Research highlights: → In an E4 framework China's low-carbon development is compared with BAU scenario. → Low carbon energy/electricity and their related measuring indexes are discussed. → China's successful experiences on energy efficiency are summarized as EUM and IRSP. → With them China could save energy by 5.8 Btoe and reduce CO 2 by 22.2 Bton until 2030. → China must restructure its economy and rely on technology innovation for them.

  14. Techno-economic and environmental analysis of low carbon energy technologies: Indian perspective

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Vijay Prakash; Kumar, Rahul; Kumar, Manish; Deswal, Surinder; Chandna, Pankaj

    2010-09-15

    In this paper, techno-economic and an environmental investigation and analysis of Low Carbon Technologies (LCTs) has been presented, with special emphasis on India. The paper identify, analyze and recommend, on the basis of available and collected / collated information and data, the promising and potential low carbon energy technology options suited to Indian conditions for grid connected power generation. The evaluation criteria adopted include - emission reduction potential, technological feasibility, and economic viability; and on its basis recommend a detailed action plan and strategy for guiding future research and development with a more focused approach considering current Indian policy framework.

  15. Financing the low-carbon transition in a fragile world economy

    International Nuclear Information System (INIS)

    Hourcade, Jean-Charles

    2015-01-01

    An unfavorable economic situation will hinder the launching of the 'low-carbon transition' in compliance with an increase of approximately 2 deg. C - the official goal set by the international community for global warming. Reversing the perspective, this transition is seen, herein, as the grounds for a 'sustainable' growth based on a monetary policy that ties the emission of liquidities to investments in low-carbon facilities. 'Climate remediation [sic] assets' with a social value set by an agreement in the framework of the Convention on the Climate are discussed

  16. China's Development of Low-Carbon Eco-Cities and Associated Indicator Systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); He, Gang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Williams, Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-01

    China's urban population surpassed its rural population historically in 2011, when the number of Chinese living in towns and cities reached about 690 million1. In the years to come, cities in China will face major challenges as their rapidly increasing populations burden already crowded infrastructure systems and exacerbate environmental and climate change issues, threatening public health and quality of life. Low-carbon cities may be key to addressing those challenges, especially as regards mitigating and adapting to climate change. Government entities at both the central and local level have moved aggressively on building low-carbon eco-cities. According to statistics reported by the Chinese Society for Urban Studies, by February of 2011, China will have 230 cities at the prefecture-and-above level that have proposed to establish themselves as “eco-cities,” accounting for 80.1% of the 287 such cities nationally. Of those 230 cities, 133, or 46.3%, have established targets to develop specifically as “lowcarbon cities” (Chinese Society for Urban Studies 2011). Given the proposed scale of the effort, China’s potential success or failure in demonstrating and implementing low-carbon eco-cities could greatly affect how the world addresses both the climate change impacts of urbanization and the sustainable development of cities. Despite the multiple guidelines that have been developed, it remains unclear what defines a low-carbon eco-city. Additionally, although more than 100 indicators have been used or proposed for assessing such cities, few relate directly to energy use or carbon emissions. Nonetheless, policy makers and leaders continue to demand comprehensive toolboxes to facilitate development of low-carbon eco-cities. This paper presents the results of an extensive literature review of the development of low-carbon eco-cities in China. The paper also qualitatively and quantitatively analyzes 11 major indicator systems that researchers, planners

  17. Digital earth for manipulating urban greens towards achieving a low carbon urban society

    International Nuclear Information System (INIS)

    Tripathi, N G; Bedi, P

    2014-01-01

    Urban greens are integral components of urban ecosystem, contributing towards quality of life and sustainable urban development. Urban greens can help in creating Low Carbon Society (LCS) by playing an integral role through sequestering carbon. India is undergoing significant change in the process and pace of its urbanization. As the growing population becomes more urban, the importance of the way urban areas are developed and managed will be a central point of intervention for addressing climate change and maintaining low carbon trajectories in Indian cities

  18. Opportunities for A Low Carbon Future——China's Clean Revolution Ⅱ

    Institute of Scientific and Technical Information of China (English)

    Audrey GUO

    2009-01-01

    @@ Despite economic downturn,China's domestic markets continue to scale up low carbon technology.A new report that was released in Beijing in August by the Climate Group shows that in an incredibly short time China has taken the lcad in the race to develop and commercialize a range of low carbon technologies.On the back of ambitious government policies and a new breed of entrepreneurs,Chinese businesses are amongst the top producers of electric vehicles,wind turbines,solar panels and energy efficient appliances.

  19. Ageing phenomena in ULCB-NiCu steels

    International Nuclear Information System (INIS)

    Lis, A.K.; Lis, J.; Wieczorek, P.

    1999-01-01

    Effect od ageing time and temperature on microstructure development, precipitation of ε C u, advancement of recrystallization process and their influence on yield strength and fracture toughness properties K IC as well as high Charpy V impact energy CVN = 84 J at 120 o C of ultra low carbon bainitic copper bearing steels have ben discussed. (author)

  20. Assessing resistance of stabilized corrosion resistant steels to intergranular corrosion

    International Nuclear Information System (INIS)

    Karas, A.; Cihal, V. Jr.; Vanek, V.; Herzan, J.; Protiva, K.; Cihal, V.

    1987-01-01

    Resistance to intergranular corrosion was determined for four types of titanium-stabilized steels from the coefficients of stabilization efficiency according to the degree the chemical composition was known. The ATA SUPER steel showed the highest resistance parameter value. The resistance of this type of steel of a specific composition, showing a relatively low value of mean nitrogen content was compared with steel of an optimized chemical composition and with low-carbon niobium stabilized, molybdenum modified steels. The comparison showed guarantees of a sufficient resistance of the steel to intergranular corrosion. The method of assessing the resistance to intergranular corrosion using the calculation of the minimum content of Cr', i.e., the effective chromium content, and the maximum effective carbon content C' giving the resistance parameter k seems to be prospective for practical use in the production of corrosion resistant steels. (author). 1 tab., 5 figs., 15 refs

  1. On the corrosion resistance of 01Kh25 ferritic steel

    International Nuclear Information System (INIS)

    Eremeeva, R.A.; Koval', E.K.

    1989-01-01

    Effect of non-ferrous metal ions on corrosion behaviour of 01Kh25 specific low carbon steel as compared to austenitic 12Kh18N10T and 06KhN28MDT steels in boiling solutions of sulfuric and nitric acids and their mixture is studied. Compositions initating commercial ones are chosen the media. It is shown that trough corrosion resistance of 01Kh25 steel in 10% H 2 SO 4 is two order below 06KhN28MDT austenitic steel in presence of Cu 2+ ions as a result of the surface passivation corrosion resistance of ferritic steel is an order higher the austenitic ones. Ferrite steel resistance in the nitric acid and its mixture with sulfuric acid is five timesas much as in 12Kh18N10T austenitic steel

  2. Three-Sheet Spot Welding of Advanced High-Strength Steels

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Friis, Kasper Storgaard; Zhang, W.

    2011-01-01

    The automotive industry has introduced the three-layer weld configuration, which represents new challenges compared to normal two-sheet lap welds. The process is further complicated by introducing high-strength steels in the joint. The present article investigates the weldability of thin, low....... The weld mechanisms are analyzed numerically and compared with metallographic analyses showing how the primary bonding mechanism between the thin, low-carbon steel sheet and the thicker sheet of high-strength steel is solid-state bonding, whereas the two high-strength steels are joined by melting, forming...... a weld nugget at their mutual interface. Despite the absence of the typical fusion nugget through the interface between the low-carbon steel and high-strength steel, the weld strengths obtained are acceptable. The failure mechanism in destructive testing is ductile fracture with plug failure....

  3. Non-nuclear, low-carbon, or both? The case of Taiwan

    International Nuclear Information System (INIS)

    Chen, Yen-Heng Henry

    2013-01-01

    The Fukushima nuclear accident in Japan has renewed debates on the safety of nuclear power, possibly hurting the role of nuclear power in efforts to limit CO 2 emissions. I develop a dynamic economy-wide model of Taiwan with a detailed set of technology options in the power sector to examine the implications of adopting different carbon and nuclear power policies on CO 2 emissions and the economy. Without a carbon mitigation policy, limiting nuclear power has a small economic cost for Taiwan, but CO 2 emissions may increase by around 4.5% by 2050 when nuclear is replaced by fossil-based generation. With a low-carbon target of a 50% reduction from year 2000 levels by 2050, the costs of cutting CO 2 emissions are greatly reduced if both carbon sequestration and nuclear expansion were viable. This study finds that converting Taiwan's industrial structure into a less energy-intensive one is crucial to carry out the non-nuclear and low-carbon environment. - Highlights: • This study provides an analysis for Taiwan under a low-carbon policy with or without the nuclear option. • A new approach that improves the modeling of non-dispatchable generation is presented. • Emission reduction costs are greatly reduced if both carbon sequestration and nuclear expansion were viable. • A less energy-intensive industrial structure is crucial in pursuing a non-nuclear and low carbon environment

  4. Promoting low-carbon city through industrial symbiosis: A case in China by applying HPIMO model

    International Nuclear Information System (INIS)

    Dong, Liang; Fujita, Tsuyoshi; Zhang, Hui; Dai, Ming; Fujii, Minoru; Ohnishi, Satoshi; Geng, Yong; Liu, Zhu

    2013-01-01

    China launched low-carbon city strategy to respond global climate change. Industrial symbiosis (IS) could generate both economic and environmental benefits in clustered industries and communities. This research shed light on how industrial symbiosis contributes to city's low-carbon development. An urban-level hybrid physical input and monetary output (HPIMO) model which covers physical energy inputs and air pollutants emissions, is established for addressing case study in a Chinese typical industrial city (Liuzhou). Based on current energy consumption and industrial symbiosis and the application of HPIMO model, scenarios related to industrial symbiosis, including waste plastics recycling, scrap tires recycling, flying ash recycling and biomass utilization are explored. Results show that compared with business-as-usual (BAU) scenario, IS can reduce solid wastes and further contribute to the co-benefits of energy saving, CO 2 emissions reduction and air pollutants reduction. The finding is critical for national low-carbon strategy. Finally, policy implications to support the ever-improvement of IS promotion in China are proposed and discussed. - Highlights: • Industrial symbiosis could contribute to low-carbon city in terms of co-benefit. • Co-benefit of IS was in terms of waste reduction and air pollutants reduction. • Waste plastics recycling and biomass utilization generated large co-benefit. • Coal fly ash recycling reduced the solid waste while increased air pollutants. • The prices of wastes and facilities investment affected the total cost-benefit

  5. Developing and Using Green Skills for the Transition to a Low Carbon Economy

    Science.gov (United States)

    Brown, Mike

    2015-01-01

    One of the strategies being advocated in response to climate change is the need to transition to a low carbon economy. Current projections show that within this transition, new jobs will be created, some eliminated and most others subjected to change. This article reports findings from interviews with a selection of twenty participants who are…

  6. Operational flexibility and economics of power plants in future low-carbon power systems

    NARCIS (Netherlands)

    Brouwer, Anne Sjoerd; van den Broek, Machteld; Seebregts, Ad; Faaij, André

    2015-01-01

    Future power systems will require large shares of low-carbon generators such as renewables and power plants with Carbon Capture and Storage (CCS) to keep global warming below 2. °C. Intermittent renewables increase the system-wide demand for flexibility and affect the operation of thermal power

  7. Renewable and low-carbon energies as mitigation options of climate change for China

    NARCIS (Netherlands)

    Urban, F.; Benders, R. M. J.; Moll, H. C.

    This article discusses how renewable and low-carbon energies can serve as mitigation options of climate change in China's power sector. Our study is based on scenarios developed in PowerPlan, a bottom-up model simulating a countries' power sector and its emissions. We first adjusted the model to

  8. A Guidebook for Low-Carbon Development at the Local Level

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; Price, Lynn; Ohshita, Stephanie; Zheng, Nina; Min, Hu

    2011-10-31

    This report aims to provide a manual with a menu of the successful policies and measures for local governments in China to create low carbon plan or climate action plans. This manual includes a comprehensive list of successful policies and best practices.

  9. Exploring a low carbon development in rural China : the role of households

    NARCIS (Netherlands)

    Liu Wenling, Wenling

    2013-01-01

    As the largest emitter of greenhouse gasses in the world, China is facing great pressure to reduce these emissions in order to mitigate global climate change. Developing a low carbon economy has been initiated in many countries, including China, as a means to tackle this issue. China’s actions

  10. Simulation and Prediction of Decarbonated Development in Tourist Attractions Associated with Low-carbon Economy

    Directory of Open Access Journals (Sweden)

    Yuyan Luo

    2014-04-01

    Full Text Available In the field of tourism, the development of tourist attractions is gradually playing a crucial role in tourism economy, regional economy and national economy. While tourism economy is stimulated by growing demand, tourist attractions have been facing the situation that ecological environment is becoming fragile and environmental protection is increasingly difficult in China. As low-carbon economy is highlighted more than ever before, how to develop green economy, how to apply theories and technologies, which are related to low-carbon economy, to push forward decarbonation, to protect the ecological environment, and to boost the development of tourism economy have become the core problems for the sustainable development of tourist attractions system. In addition, this system has drawn the attention of scholars and practitioners in recent years. On the basis of low-carbon economy, this paper tries to define the decarbonated development goals and the connotation of tourist attractions system. In addition, it also discusses system structure associated with system dynamics and system engineering, and constructs system simulation model. In the end, a case study is conducted, that is, to predict the development trend of Jiuzhai Valley by adopting the constructed system so as to extend the previous research on low-carbon tourism and to guide the decarbonated development in tourist attractions.

  11. Informed public choices for low-carbon electricity portfolios using a computer decision tool.

    Science.gov (United States)

    Mayer, Lauren A Fleishman; Bruine de Bruin, Wändi; Morgan, M Granger

    2014-04-01

    Reducing CO2 emissions from the electricity sector will likely require policies that encourage the widespread deployment of a diverse mix of low-carbon electricity generation technologies. Public discourse informs such policies. To make informed decisions and to productively engage in public discourse, citizens need to understand the trade-offs between electricity technologies proposed for widespread deployment. Building on previous paper-and-pencil studies, we developed a computer tool that aimed to help nonexperts make informed decisions about the challenges faced in achieving a low-carbon energy future. We report on an initial usability study of this interactive computer tool. After providing participants with comparative and balanced information about 10 electricity technologies, we asked them to design a low-carbon electricity portfolio. Participants used the interactive computer tool, which constrained portfolio designs to be realistic and yield low CO2 emissions. As they changed their portfolios, the tool updated information about projected CO2 emissions, electricity costs, and specific environmental impacts. As in the previous paper-and-pencil studies, most participants designed diverse portfolios that included energy efficiency, nuclear, coal with carbon capture and sequestration, natural gas, and wind. Our results suggest that participants understood the tool and used it consistently. The tool may be downloaded from http://cedmcenter.org/tools-for-cedm/informing-the-public-about-low-carbon-technologies/ .

  12. Development of Affordable, Low-Carbon Hydrogen Supplies at an Industrial Scale

    Science.gov (United States)

    Roddy, Dermot J.

    2008-01-01

    An existing industrial hydrogen generation and distribution infrastructure is described, and a number of large-scale investment projects are outlined. All of these projects have the potential to generate significant volumes of low-cost, low-carbon hydrogen. The technologies concerned range from gasification of coal with carbon capture and storage…

  13. The green economy mirage? Examining the environmental implications of low-carbon growth plans in Taiwan

    NARCIS (Netherlands)

    Chao, C.-W.; Heijungs, R.; Ma, H.-W.

    2013-01-01

    Taiwan is attempting to implement the concept of a green economy through a Low Carbon Growth Plan (LCGP). However, the existing decision support tools for this measure have three key limitations: ignorance regarding the open economy; a lack of life cycle thinking; and limited categories of

  14. Managing Risk Aversion for Low-Carbon Supply Chains with Emission Abatement Outsourcing.

    Science.gov (United States)

    Wang, Qinpeng; He, Longfei

    2018-02-21

    Reducing carbon emissions, including emission abatement outsourcing at the supply-chain level, is becoming a significant but challenging problem in practice. Confronting this challenge, we therefore break down the practice to focus on a low-carbon supply chain consisting of one supplier, one manufacturer and one third-party emission-reducing contractor. The contractor offers a carbon reduction service to the manufacturer. In view of the increasing proportion of Greenhouse Gases (GHG) emissions and absence of carbon reduction policies in developing countries, we adopt the prospect of consumers' low-carbon preferences to capture the demand sensitivity on carbon emission. By exploiting the Mean-Variance (MV) model, we develop a supply chain game model considering risk aversion. Comparing the supply chain performances of the cases under risk neutrality and risk aversion, we investigate the impact of the risk aversion of the supplier and the manufacturer on the low-carbon supply chain performances, respectively. We show that the risk aversion of chain members will not influence the relationship underlain by the profit-sharing contract between the manufacturer and contractor, whereas they may extend the supplier's concerning range. Although the manufacturer's risk aversion has a positive impact on the wholesale price, interestingly, the supplier's impact on the wholesale price is negative. Furthermore, we propose a contract to coordinate the risk-averse low-carbon supply chain by tuning the aversion levels of the supplier and the manufacturer, respectively. Through numerical study, we draw on managerial insights for industrial practitioners to adopt a low carbon strategy potentially by managing the risk attitudes along the supply chain channel.

  15. Prioritizing low-carbon energy sources to enhance China’s energy security

    International Nuclear Information System (INIS)

    Ren, Jingzheng; Sovacool, Benjamin K.

    2015-01-01

    Highlights: • Four dimensions and ten metrics are used for energy security assessment. • Both qualitative and quantitative metrics are considered for energy security. • AHP has been used to quantify qualitative metrics. • TOPSIS method has been used for prioritize the low-carbon energy sources. • Sensitivity analysis and integrated ranking have been carried out. - Abstract: This paper explores how low-carbon systems compare to each other in terms of their net effect on Chinese energy security, and how they ought to be ranked and strategized into an optimal and integrated resource plan. The paper utilizes Analytic Hierarchy Process (AHP) to first determine the relative performances of hydroelectricity, wind energy, solar energy, biomass energy, and nuclear power with respect to the energy security dimensions of availability, affordability, accessibility, and acceptability. Both qualitative and quantitative metrics are considered. It relies on AHP to calculate the relative weights of the qualitative metrics attached to these dimensions of energy security for each of our five low carbon energy sources. Then, energy security performance is determined by aggregating multiple, weighted metrics into a generic index based on the method of TOPSIS and then tweaked with a sensitivity analysis. Finally, an integrated method has been developed to rank the low-carbon energy systems from most to least important, with major implications for Chinese decision-makers and stakeholders. We conclude that hydroelectricity and wind power are the two low-carbon energy sources with the most potential to enhance China’s energy security. By contrast, nuclear and solar power have the least potential

  16. Managing Risk Aversion for Low-Carbon Supply Chains with Emission Abatement Outsourcing

    Science.gov (United States)

    Wang, Qinpeng; He, Longfei

    2018-01-01

    Reducing carbon emissions, including emission abatement outsourcing at the supply-chain level, is becoming a significant but challenging problem in practice. Confronting this challenge, we therefore break down the practice to focus on a low-carbon supply chain consisting of one supplier, one manufacturer and one third-party emission-reducing contractor. The contractor offers a carbon reduction service to the manufacturer. In view of the increasing proportion of Greenhouse Gases (GHG) emissions and absence of carbon reduction policies in developing countries, we adopt the prospect of consumers’ low-carbon preferences to capture the demand sensitivity on carbon emission. By exploiting the Mean-Variance (MV) model, we develop a supply chain game model considering risk aversion. Comparing the supply chain performances of the cases under risk neutrality and risk aversion, we investigate the impact of the risk aversion of the supplier and the manufacturer on the low-carbon supply chain performances, respectively. We show that the risk aversion of chain members will not influence the relationship underlain by the profit-sharing contract between the manufacturer and contractor, whereas they may extend the supplier’s concerning range. Although the manufacturer’s risk aversion has a positive impact on the wholesale price, interestingly, the supplier’s impact on the wholesale price is negative. Furthermore, we propose a contract to coordinate the risk-averse low-carbon supply chain by tuning the aversion levels of the supplier and the manufacturer, respectively. Through numerical study, we draw on managerial insights for industrial practitioners to adopt a low carbon strategy potentially by managing the risk attitudes along the supply chain channel. PMID:29466281

  17. Managing Risk Aversion for Low-Carbon Supply Chains with Emission Abatement Outsourcing

    Directory of Open Access Journals (Sweden)

    Qinpeng Wang

    2018-02-01

    Full Text Available Reducing carbon emissions, including emission abatement outsourcing at the supply-chain level, is becoming a significant but challenging problem in practice. Confronting this challenge, we therefore break down the practice to focus on a low-carbon supply chain consisting of one supplier, one manufacturer and one third-party emission-reducing contractor. The contractor offers a carbon reduction service to the manufacturer. In view of the increasing proportion of Greenhouse Gases (GHG emissions and absence of carbon reduction policies in developing countries, we adopt the prospect of consumers’ low-carbon preferences to capture the demand sensitivity on carbon emission. By exploiting the Mean-Variance (MV model, we develop a supply chain game model considering risk aversion. Comparing the supply chain performances of the cases under risk neutrality and risk aversion, we investigate the impact of the risk aversion of the supplier and the manufacturer on the low-carbon supply chain performances, respectively. We show that the risk aversion of chain members will not influence the relationship underlain by the profit-sharing contract between the manufacturer and contractor, whereas they may extend the supplier’s concerning range. Although the manufacturer’s risk aversion has a positive impact on the wholesale price, interestingly, the supplier’s impact on the wholesale price is negative. Furthermore, we propose a contract to coordinate the risk-averse low-carbon supply chain by tuning the aversion levels of the supplier and the manufacturer, respectively. Through numerical study, we draw on managerial insights for industrial practitioners to adopt a low carbon strategy potentially by managing the risk attitudes along the supply chain channel.

  18. Carbon Impact Analytics - Designing low carbon indices based on Carbon Impact Analytics indicators

    International Nuclear Information System (INIS)

    2016-01-01

    Investors are increasingly exposed to carbon risks and now face the challenge of managing these risks and developing climate-resilient investment strategies. Carbon Impact Analytics (CIA), an innovative methodology for analyzing the full carbon impact of a portfolio or index, equips investors and asset managers with the tools necessary to reduce their climate-related risks but also to seize the opportunities offered by the ongoing energy transition. Investors, asset managers and other financial institutions may use CIA results to: - measure and manage risks, - optimize their contribution to the energy transition, - seize opportunities associated with climate change mitigation, - report on GHG emissions and savings (for regulatory purposes or voluntarily), - engage in dialogue with companies, - reallocate investment portfolios, - and build new low-carbon indices. In this report, Carbone 4 offers a detailed look into how CIA indicators can be used to either 1) reallocate an existing portfolio or index to achieve maximal carbon performance or 2) build new low carbon indices from the ground up, drawn from Carbone 4's ever-growing database of CIA-analyzed firms. Two main levers were used to optimize CIA output: 1. Sectorial reallocation: exclusion of fossil fuel-related sectors or insertion of low carbon pure players; 2. Intra-sectorial reallocation: best-in-class approach within a sector. Sectorial and intra-sectorial methods may be applied in conjunction with one another to maximize results. For example, a best-in-class + fossil fuel-free index may be constructed by first excluding the fossil fuel sector and then applying a CIA best-in-class approach to all remaining sectors. This report offers a detailed look into how CIA indicators can be used to rework portfolios or indices to maximize carbon performance or to build low carbon indices from the ground up. These methods are illustrated via two preliminary examples of indices designed by Carbone 4: the reallocated

  19. Low-Carbon City Policy Databook: 72 Policy Recommendations for Chinese Cities from the Benchmarking and Energy Savings Tool for Low Carbon Cities

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Ohshita, Stephanie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Khanna, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Hong, Lixuan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; He, Gang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Romankiewicz, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Division. China Energy Group; Min, Hu [Energy Foundation China, Beijing (China)

    2016-07-01

    This report is designed to help city authorities evaluate and prioritize more than 70 different policy strategies that can reduce their city’s energy use and carbon-based greenhouse gas emissions of carbon dioxide (CO2) and methane (CH4). Local government officials, researchers, and planners can utilize the report to identify policies most relevant to local circumstances and to develop a low carbon city action plan that can be implemented in phases, over a multi-year timeframe. The policies cover nine city sectors: industry, public and commercial buildings, residential buildings, transportation, power and heat, street lighting, water & wastewater, solid waste, and urban green space. See Table 1 for a listing of the policies. Recognizing the prominence of urban industry in the energy and carbon inventories of Chinese cities, this report includes low carbon city policies for the industrial sector. The policies gathered here have proven effective in multiple locations around the world and have the potential to achieve future energy and carbon savings in Chinese cities.

  20. Aircraft Steels

    Science.gov (United States)

    2009-02-19

    component usage. PH 13-8Mo is a precipitation-hardenable martensitic stainless steel combining excellent corrosion resistance with strength. Custom 465 is...a martensitic , age-hardenable stainless steel capable of about 1,724 MPa (250 ksi) UTS when peak-aged (H900 condition). Especially, this steel can...NOTES 14. ABSTRACT Five high strength steels (4340, 300M, AerMet 100, Ferrium S53, and Hy-Tuf) and four stainless steels (High Nitrogen, 13

  1. The effects of laser welding parameters on the microstructure of ferritic and duplex stainless steels welds

    Science.gov (United States)

    Pekkarinen, J.; Kujanpää, V.

    This study is focused to determine empirically, which microstructural changes occur in ferritic and duplex stainless steels when heat input is controlled by welding parameters. Test welds were done autogenously bead-on-plate without shielding gas using 5 kW fiber laser. For comparison, some gas tungsten arc welds were made. Used test material were 1.4016 (AISI 430) and 1.4003 (low-carbon ferritic) type steels in ferritic steels group and 1.4162 (low-alloyed duplex, LDX2101) and 1.4462 (AISI 2205) type steels in duplex steels group. Microstructural changes in welds were identified and examined using optical metallographic methods.

  2. Visualizing the application of GIS in transformation towards a sustainable development and a low carbon society

    International Nuclear Information System (INIS)

    Ahmad, M H; Ariffin, A; Malik, T A

    2014-01-01

    A strategy for sustainable development is a significant milestone on the road to a more socially, economically and environmentally responsible society. It creates a framework within which the stakeholders can make a strong contribution to a better future. Because of the merits and growing interest in sustainable development, the race is on for researchers and stakeholders in the construction sector to initiate actions to reduce the negative impacts of development and sharpen their competitive edge. The cities should be created with a vision which supports harmonious communities and living conditions through sustainable urban development. The resources must be used efficiently while reducing the development impact on human health and environment during the buildings' life cycle. Environmental auditing and pressure-state response based models to monitor sustainable development in Malaysia should be developed. A data availability and sharing system should be developed and implemented to facilitate for the use in the establishment of sustainable development and low carbon society. Ideas which affect millions of people and guide the policies of nations must be accessible to all. Only thus can they permeate the institutions from the local to the global level. Creating sustainable development and low carbon societies depends on the knowledge and involvement of all stakeholders in the industry. So what is our level of understanding of GIS and its application? The development of geospatial data in Malaysia is important because the successful implementation of sustainable development and low carbon projects depend largely on the availability of geospatial information. It would facilitate the stakeholders and resolve some of the problems regarding the availability, quality, organisation, accessibility and sharing of spatial information. The introduction of GIS may change the way for better sustainable urban development and low carbon society performance. The use of GIS

  3. Visualizing the application of GIS in transformation towards a sustainable development and a low carbon society

    Science.gov (United States)

    Ahmad, M. H.; Ariffin, A.; Malik, T. A.

    2014-02-01

    A strategy for sustainable development is a significant milestone on the road to a more socially, economically and environmentally responsible society. It creates a framework within which the stakeholders can make a strong contribution to a better future. Because of the merits and growing interest in sustainable development, the race is on for researchers and stakeholders in the construction sector to initiate actions to reduce the negative impacts of development and sharpen their competitive edge. The cities should be created with a vision which supports harmonious communities and living conditions through sustainable urban development. The resources must be used efficiently while reducing the development impact on human health and environment during the buildings' life cycle. Environmental auditing and pressure-state response based models to monitor sustainable development in Malaysia should be developed. A data availability and sharing system should be developed and implemented to facilitate for the use in the establishment of sustainable development and low carbon society. Ideas which affect millions of people and guide the policies of nations must be accessible to all. Only thus can they permeate the institutions from the local to the global level. Creating sustainable development and low carbon societies depends on the knowledge and involvement of all stakeholders in the industry. So what is our level of understanding of GIS and its application? The development of geospatial data in Malaysia is important because the successful implementation of sustainable development and low carbon projects depend largely on the availability of geospatial information. It would facilitate the stakeholders and resolve some of the problems regarding the availability, quality, organisation, accessibility and sharing of spatial information. The introduction of GIS may change the way for better sustainable urban development and low carbon society performance. The use of GIS is to

  4. Capturing low-carbon power system dynamics : Interactions between intermittent renewables and power plants with CO2 capture and storage

    NARCIS (Netherlands)

    Brouwer, Anne-Sjoerd

    2015-01-01

    Low-carbon power systems are needed by the year 2050 to meet climate change mitigation targets. This dissertation investigates the operational and economic feasibility of such future low-carbon power systems by simulating the Dutch and European power systems. Particular attention is paid to the

  5. Tendances Carbone no. 77 'Low-carbon innovation is up, but not because of the EU ETS'

    International Nuclear Information System (INIS)

    Calel, Raphael; Dechezlepretre, Antoine

    2013-01-01

    Among the publications of CDC Climat Research, 'Tendances Carbone' bulletin specifically studies the developments of the European market for CO 2 allowances. This issue addresses the following points: The EU ETS is the main instrument of European climate policy, and many policy-makers envisage it as a driving force of the EU's transition to a low-carbon economy. By putting a price on emissions, the scheme is expected to encourage heavy polluters to develop new low-carbon technologies. At first glance it is encouraging to notice, then, that patenting for low-carbon technologies has surged in Europe since 2005. When analysing new data we find compelling evidence that the EU ETS has indeed encouraged regulated companies to develop new low-carbon technologies, but this effect is concentrated among too few companies to account for the surge in low-carbon patenting

  6. Chemical heat treatment of low alloyed maraging steels

    Energy Technology Data Exchange (ETDEWEB)

    Malinov, L S; Korotich, I K [Zhdanovskij Metallurgicheskij Inst. (Ukrainian SSR)

    1979-09-01

    The investigation concerned the nitriding, cementation, chromizing, borating of economically alloyed maraging grade 04Kh2N5MFYu steel. The investigated methods of chemothermal treatment were found to considerably increase the hardness of the surface layer of the maraging steel. The high tempering of the grade 04Kh2N5MFYu cemented and hardened steel was found to produce secondary hardening. On chromizing, the diffusion layer is an alloyed ferrite which strengthens because of the dispersion hardening on ageing. The formation of the plastic low-carbon martensite at relatively small cooling rates greatly decreases the tendency of the boride layer to cracking.

  7. Nanostructures by Severe Plastic Deformation of Steels: Advantages and Problems

    Directory of Open Access Journals (Sweden)

    Dobatkin, S. V.

    2006-01-01

    Full Text Available The aim of this paper is to consider the features of structure evolution during severe plastic deformation (SPD of steels and its influence on mechanical properties. The investigation have been carried out mainly on low carbon steels as well as on austenitic stainless steels after SPD by torsion under high pressure (HPT and equal channel angular (ECA pressing. Structure formation dependencies on temperature deformation conditions, strain degree, chemical composition, initial state and pressure are considered. The role of phase transformations for additional grain refinement, namely, martensitic transformation, precipitation of carbide particles during SPD and heating is underlined.

  8. An Optimal Allocation Model of Public Transit Mode Proportion for the Low-Carbon Transportation

    Directory of Open Access Journals (Sweden)

    Linjun Lu

    2015-01-01

    Full Text Available Public transit has been widely recognized as a potential way to develop low-carbon transportation. In this paper, an optimal allocation model of public transit mode proportion (MPMP has been built to achieve the low-carbon public transit. Optimal ratios of passenger traffic for rail, bus, and taxi are derived by running the model using typical data. With different values of traffic demand, construction cost, travel time, and accessibilities, MPMP can generate corresponding optimal ratios, benefiting decision impacts analysis and decision makers. Instead of considering public transit as a united system, it is separated into units in this paper. And Shanghai is used to test model validity and practicality.

  9. Developing nuclear power to realize low-carbon and economic sustainable development of China

    International Nuclear Information System (INIS)

    Zhang Xingfa

    2012-01-01

    Thermal power is the primary power energy of China, whose basic primary energy consumption is mostly burning coal. And thereby carbon dioxide emission reduction becomes much difficult in China. Seeking low-carbon discharge power energy is the necessary trend in China electric power development. Among the new energy, wind power, hydropower and solar energy have some distinctive shortcoming, which can not make up the energy growth demand with the rapid growth of the economy. Comparing to other kinds of electric energy, the nuclear power possesses the evident advantages, it will become the basis energy to carry out the goal of energy conservation and emission reduction in China and developing nuclear power can realize the sustainable development of China economy under low-carbon condition. (author)

  10. Study on Chinese model of low carbon economy-energy-electricity-environment

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhaoguang

    2010-09-15

    With the successful experience on energy efficiency in the past 30 years in China, it can be summarized as Energy Usage Management(EUM) and Integrated Resource Strategic Planning(IRSP). They will play essential role in Low Carbon Economy. The model of Low Carbon Economy-Energy-Electricity-Environment and an outlook of Chinese economic growth, energy-electricity demand, and renewable energy generation have been studied in this paper. It has been shown that China would save energy 4.38 billion toe and reduce CO2 emission 16.55 billion ton by EUM, and would save energy 1.5 billion toe and reduce CO2 emission 5.7 Btons by IRSP during 2010-2030.

  11. Analysis of responses to the microgeneration strategy and low carbon buildings programme consultation

    Energy Technology Data Exchange (ETDEWEB)

    Gibbard, J.; Long, S.; McCartney, K.; Rushton, K.

    2005-10-15

    This report summarises and analyses the written responses to the consultation document, 'Microgeneration Strategy and Low Carbon Buildings Programme', issued by the Department of Trade and Industry (DTI) in June 2005. Responses were received from 204 different organisations representing 29 stakeholder groups. The consultation document contained 41 core questions divided into eight sections: general; product development and deployment; communications; economics; installation; Low Carbon Buildings Programme; physical infrastructure; and local authorities and regional bodies. In the analysis, the responses to these questions were categorised according to whether they represented a 'clear consensus', a 'majority view', 'supporting themes' and 'divergent themes'. Using these categories, stakeholder agreement on the eight strategic issues is summarised in a matrix. The report is divided into three sections: introduction; summary of responses; and key findings. The respondents are listed in an appendix. Another appendix reproduces the consultation questions.

  12. A monetary plan for upgrading climate finance and support the low-carbon transition

    International Nuclear Information System (INIS)

    Hourcade, Jean Charles; Cassen, Christophe

    2015-01-01

    This article examines how carbon finance can be part of a general reform of the financial system. Climate policies can indeed stimulate a sustainable and inclusive climate finance, in line with the call of the Cancun Agreement for a paradigm shift in climate negotiations. The mechanism described in this article is based on the adoption by Parties to the negotiations of a social value of carbon to trigger a wave of low-carbon investments in the world. Central banks offer credit lines for commercial banks backed by this social value of carbon, which are then used to cut the risk to invest in low- carbon investments. A future agreement in Paris next year should support this type of mechanisms.

  13. Low Carbon Design Research on the Space Layout Types of Office Buildings

    Science.gov (United States)

    Xia, Bing

    2018-01-01

    It is beneficial to find out the relationship of the spatial layout and low-carbon design in order to reduce buildings’ carbon emissions in the conceptual design phase. This paper analyzes and compares shape coefficient values, annual energy consumption and lighting performance of office buildings of different space layout types in Shanghai. Based on morphological characteristics of different types, the study also analyzes and presents low-carbon design strategies for each single type. This study assumes that architects should conduct passive and active design according to the specific building space layout, so that to make best use of the advantages and bypassing the disadvantages, in order to maximally reduce buildings’ carbon emissions.

  14. Developing knowledge and strategies for enabling and governing transitions to a low carbon society

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Jørgensen, Ulrik; Lauridsen, Erik Hagelskjær

    research alliance “Enabling and governing transitions to a low carbon society” during 2010-2013. The aim of this alliance is to conceptualize the dynamics of transition processes towards a low carbon society by involving the diverse set of actors from consumers to governmental agencies, companies...... and organizations. Transition of the path-dependent, socio-technical regimes in the energy system is a governance challenge, since transitions need to occur simultaneously in different arenas without necessarily having a specific „centre‟ of co-ordination. Changes of regimes require innovative breakthroughs......, companies, cities, and national and international policy. Theoretically the research alliance builds upon a combination of theories including social practice theory, innovation economy, institutional theory, actor-network theory and governance theory. Through a combination of historical analysis, case...

  15. Research of System Building Basing on the Low Carbon Economy About Carbon Accounting for the Enterprise

    Directory of Open Access Journals (Sweden)

    Yao Liqiong

    2016-01-01

    Full Text Available As global warming has become truth, is developing as a new economic model, The new economic development model has given rise to an important branch of environmental accounting, namely carbon accounting. At first, this paper discusses the carbon accounting theoretical foundation comprehensively, and then analyzes the environment of the construction of the carbon accounting system. The focus of the article is to build enterprise carbon accounting system, it covers the confirmation and measurement, record and information disclosure of the enterprise carbon accounting on the way of low carbon economy, its core is the processing of carbon emission rights, information disclosure mode and content, etc.; The purpose of this paper is to build enterprise carbon accounting system which is suitable for China’s national conditions, in order to provide certain reference and theoretical support for the low carbon economy development of our country.

  16. Low Carbon Grid Study: Analysis of a 50% Emission Reduction in California

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ehlen, Ali [Center for Energy Efficiency and Renewable Technologies, Sacramento, CA (United States); Caldwell, James H. [Center for Energy Efficiency and Renewable Technologies, Sacramento, CA (United States)

    2016-01-07

    The California 2030 Low Carbon Grid Study (LCGS) analyzes the grid impacts of a variety of scenarios that achieve 50% carbon emission reductions from California's electric power sector. Impacts are characterized based on several key operational and economic metrics, including production costs, emissions, curtailment, and impacts on the operation of gas generation and imports. The modeling results indicate that achieving a low-carbon grid (with emissions 50% below 2012 levels) is possible by 2030 with relatively limited curtailment (less than 1%) if institutional frameworks are flexible. Less flexible institutional frameworks and a less diverse generation portfolio could lead to higher curtailment (up to 10%), operational costs (up to $800 million higher), and carbon emissions (up to 14% higher).

  17. Analysis of responses to the microgeneration strategy and low carbon buildings programme consultation

    Energy Technology Data Exchange (ETDEWEB)

    Gibbard, J; Long, S; McCartney, K; Rushton, K

    2005-10-15

    This report summarises and analyses the written responses to the consultation document, 'Microgeneration Strategy and Low Carbon Buildings Programme', issued by the Department of Trade and Industry (DTI) in June 2005. Responses were received from 204 different organisations representing 29 stakeholder groups. The consultation document contained 41 core questions divided into eight sections: general; product development and deployment; communications; economics; installation; Low Carbon Buildings Programme; physical infrastructure; and local authorities and regional bodies. In the analysis, the responses to these questions were categorised according to whether they represented a 'clear consensus', a 'majority view', 'supporting themes' and 'divergent themes'. Using these categories, stakeholder agreement on the eight strategic issues is summarised in a matrix. The report is divided into three sections: introduction; summary of responses; and key findings. The respondents are listed in an appendix. Another appendix reproduces the consultation questions.

  18. A low-carbon future: Spatial planning's role in enhancing technological innovation in the built environment

    International Nuclear Information System (INIS)

    Crawford, Jenny; French, Will

    2008-01-01

    The scope of spatial planning activity includes issues of governance, corporate organisation, policy integration, statutory and regulatory frameworks, and technical analysis and design. The nature of its potential contribution to achieving low-carbon built environments will vary according to the resolution of tensions between pressures for leadership, consistent decision making and speed of change and the value placed on diversity, flexibility and innovation. A planning system that can support technological innovation will be characterised by high levels of organisational and institutional capacity and high-quality knowledge systems that support a focus on delivering place-based objectives. The paper reflects on further aspects of such a system and the issues that spatial planning needs to address in delivering low-carbon energy systems

  19. Bringing the Low-Carbon Agenda to China: A Study in Transnational Policy Diffusion

    Directory of Open Access Journals (Sweden)

    Andreas Hofem

    2013-01-01

    Full Text Available This study traces the transnational interactions that contributed to introducing the low-carbon economy agenda into Chinese policymaking. A microprocessual two-level analysis (outside-in as well as inside-access is employed to analyse transnational and domestic exchanges. The study provides evidence that low-carbon agenda-setting – introduced by transnational actors, backed by foreign funding, promoted by policy entrepreneurs from domestic research institutes, propelled by top-level attention, but only gradually and cautiously adopted by the government bureaucracy – can be considered a case of effective transnational diffusion based on converging perceptions of novel policy challenges and options. Opinion leaders and policy-brokers from the government-linked scientific community functioned as effective access points to the Chinese government’s policy agenda.

  20. An ethical assessment of low carbon vehicles using cost benefit analysis

    OpenAIRE

    Thomopoulos, Nikolas; Harrison, Gillian

    2016-01-01

    Global concerns about climate change, as confirmed at COP21, have led to lower carbon emissions environmental policies, particularly in the road transport sector. Through an empirical analysis of low carbon vehicle (LCV) policies in California, this paper contrasts the findings from diverse distribution theories between income quintiles - used as a proxy for societal groups - to address vertical equity concerns and offer an overview of impact distribution to policy makers. Thus, it contribute...

  1. The impact of Chinese carbon emission trading scheme (ETS) on low carbon energy (LCE) investment

    International Nuclear Information System (INIS)

    Mo, Jian-Lei; Agnolucci, Paolo; Jiang, Mao-Rong; Fan, Ying

    2016-01-01

    China is planning to introduce emission trading scheme (ETS) to decrease CO_2 emission. As low carbon energy (LCE) will play a pivotal role in reducing CO_2 emissions, our paper is to assess the extent and the conditions under which a carbon ETS can deliver LCE investment in China. We chose wind technology as a case study and a real-option based model was built to explore the impact of a number of variables and design features on investment decisions, e.g. carbon and electricity price, carbon market risk, carbon price floor and ceiling and on-grid ratio. We compute critical values of these variables and features and explore trade-offs among them. According to our work, a carbon ETS has a significant effect on wind power plant investment although it cannot support investment in wind power on its own. Carbon price stabilization mechanisms such as carbon price floor can significantly improve the effect of carbon ETS but the critical floor to support investment is still much higher than the carbon price in China pilot ETSs. Our results show that other policy measures will be needed to promote low-carbon energy development in China. - Highlights: • The impact of Chinese emission trading scheme on low carbon energy investment is assessed. • A real-option based investment decision model under uncertainty is built and employed. • Key variables and features of ETS influencing wind power investment are explored. • Chinese carbon ETS cannot support low carbon energy investment on its own. • Other policy measures complementing ETS are still needed and should be coordinated.

  2. Safety and effective developing nuclear power to realize green and low-carbon development

    OpenAIRE

    Ye, Qi-Zhen

    2016-01-01

    This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety, environmental protection, enhancement of nuclear power technology, nuclear waste trea...

  3. Identifying and explaining framing strategies of low carbon lifestyle movement organisations

    OpenAIRE

    Buechs, M.; Saunders, C.; Wallbridge, R.; Smith, G.; Bardsley, N.

    2015-01-01

    Over the last decade we have seen the growth and development of low carbon lifestyle movement organisations, which seek to encourage members of the public to reduce their personal energy use and carbon emissions. As a first step to assess the transformational potential of such organisations, this paper examines the ways in which they frame their activities. This reveals an important challenge they face: in addressing the broader public, do they promote ‘transformative’ behaviours or do they l...

  4. Breaking the climate deadlock. A Global Deal for Our Low-Carbon Future

    International Nuclear Information System (INIS)

    Beinhocker, E.; Howard, S.; Kenber, M.; Morgan, J.; Oppenheim, J.

    2008-06-01

    This report outlines the 10 building blocks for an agreement that will create a prosperous low carbon climate-resilient world. The report is targeted at G8 + 5 leaders, policy makers, business leaders, and opinion formers from key countries. It identifies the actions and questions that need to be resolved by political and business leaders over the next 18 months to achieve a successful outcome to the UN climate change negotiations in Copenhagen in December 2009

  5. Understanding the development trends of low-carbon energy technologies: A patent analysis

    International Nuclear Information System (INIS)

    Albino, Vito; Ardito, Lorenzo; Dangelico, Rosa Maria; Messeni Petruzzelli, Antonio

    2014-01-01

    Highlights: • Governments’ strategies set important frameworks to develop and sustain low-carbon energy technologies. • Commercial activities play a key role in the low-carbon energy technologies’ development. • The number of patents that are based upon basic research is growing. - Abstract: Eco-innovations are being recognized as fundamental means to foster sustainable development, as well as to create new business opportunities. Nowadays, the eco-innovation concept is gaining ground within both academic and practitioner studies with the attempt to better understand the main dynamics underlying its nature and guide policymakers and companies in supporting its development. This paper contributes to the extant literature on eco-innovation by providing a comprehensive overview of the evolution of a specific type of eco-innovations that are playing a crucial role in the current socio-economic agenda, namely low-carbon energy technologies. Accordingly, we focus our attention on the related patenting activity of different countries and organizations over time, as well as on influencing policy initiatives and events. Hence, we collected 131,661 patents granted at the United States Patent and Trademark Office (U.S.PTO.) between 1971 and 2010, and belonging to the “Nuclear power generation”, “Alternative energy production”, and “Energy conservation” technological classes, as indicated by the International Patent Classification (IPC) Green Inventory. Our findings report the development trends of low-carbon energy technologies, as well as identify major related environmental programs, historical events, and private sector initiatives explaining those trends, hence revealing how these different circumstances have significantly influenced their development over time

  6. Assessing the dynamic material criticality of infrastructure transitions: A case of low carbon electricity

    International Nuclear Information System (INIS)

    Roelich, Katy; Dawson, David A.; Purnell, Phil; Knoeri, Christof; Revell, Ruairi; Busch, Jonathan; Steinberger, Julia K.

    2014-01-01

    Highlights: • We present a method to analyse material criticality of infrastructure transitions. • Criticality is defined as the potential for, and exposure to, supply disruption. • Our method is dynamic reducing the probability of lock-in to at-risk technologies. • We show that supply disruption potential is reducing but exposure is increasing. - Abstract: Decarbonisation of existing infrastructure systems requires a dynamic roll-out of technology at an unprecedented scale. The potential disruption in supply of critical materials could endanger such a transition to low-carbon infrastructure and, by extension, compromise energy security more broadly because low carbon technologies are reliant on these materials in a way that fossil-fuelled energy infrastructure is not. Criticality is currently defined as the combination of the potential for supply disruption and the exposure of a system of interest to that disruption. We build on this definition and develop a dynamic approach to quantifying criticality, which monitors the change in criticality during the transition towards a low-carbon infrastructure goal. This allows us to assess the relative risk of different technology pathways to reach a particular goal and reduce the probability of being ‘locked in’ to currently attractive but potentially future-critical technologies. To demonstrate, we apply our method to criticality of the proposed UK electricity system transition, with a focus on neodymium. We anticipate that the supply disruption potential of neodymium will decrease by almost 30% by 2050; however, our results show the criticality of low carbon electricity production increases ninefold over this period, as a result of increasing exposure to neodymium-reliant technologies

  7. Uncertainties in key low carbon power generation technologies - Implication for UK decarbonisation targets

    International Nuclear Information System (INIS)

    Kannan, R.

    2009-01-01

    The UK government's economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a 'what-if' framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In this paper results of six sensitivities, via restricted investments in key low carbon technologies to reflect their technical and political uncertainties, and an alternate investment strategies from perceived risk and other barriers, have been presented. (author)

  8. A Low Carbon Development Guide for Local Government Actions in China

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Nina; Zhou, Nan; Price, Lynn; Ohshita, Stephanie

    2011-05-01

    Local level actions are crucial for achieving energy-saving and greenhouse gas emission reduction targets. Yet it is challenging to implement new policies and actions due to a lack of information, funding, and capacity. This is particularly the case in developing countries such as China. Even though national energy intensity and carbon intensity targets have been set, most local governments do not have the knowledge regarding actions to achieve the targets, the cost-effectiveness of policies, the possible impact of policies, or how to design and implement a climate action plan. This paper describes a guidebook that was developed to motivate and provide local governments in China with information to create an action plan to tackle climate change and increase energy efficiency. It provides a simple step-by-step description of how action plans can be established and essential elements to be included - from preparing a GHG emission inventory to implementation of the plan. The guidebook also provides a comprehensive list of successful policies and best practices found internationally and in China to encourage low carbon development in industry, buildings, transportation, electric power generation, agriculture and forestry. This paper also presents indicators that can be used to define low-carbon development, as well as to evaluate the effectiveness of actions taken at an aggregated (city) level, and at a sectoral or end use level. The guidebook can also be used for low carbon development by local governments in other developing countries.

  9. Informed public preferences for electricity portfolios with CCS and other low-carbon technologies.

    Science.gov (United States)

    Fleishman, Lauren A; De Bruin, Wändi Bruine; Morgan, M Granger

    2010-09-01

    Public perceptions of carbon capture and sequestration (CCS) and other low-carbon electricity-generating technologies may affect the feasibility of their widespread deployment. We asked a diverse sample of 60 participants recruited from community groups in Pittsburgh, Pennsylvania to rank 10 technologies (e.g., coal with CCS, natural gas, nuclear, various renewables, and energy efficiency), and seven realistic low-carbon portfolios composed of these technologies, after receiving comprehensive and carefully balanced materials that explained the costs and benefits of each technology. Rankings were obtained in small group settings as well as individually before and after the group discussions. The ranking exercise asked participants to assume that the U.S. Congress had mandated a reduction in carbon dioxide emissions from power plants to be built in the future. Overall, rankings suggest that participants favored energy efficiency, followed by nuclear power, integrated gasification combined-cycle coal with CCS and wind. The most preferred portfolio also included these technologies. We find that these informed members of the general public preferred diverse portfolios that contained CCS and nuclear over alternatives once they fully understood the benefits, cost, and limitations of each. The materials and approach developed for this study may also have value in educating members of the general public about the challenges of achieving a low-carbon energy future. © 2010 Society for Risk Analysis.

  10. The future of Japan's power business in a low-carbon society

    International Nuclear Information System (INIS)

    Toyoda, Masakazu

    2016-01-01

    This paper examines the implication and detail of the agreement of COP 21, and clarifies the task for electric power companies and the direction of development based on this. In face of the formulation of energy mix policy for 2030, in July 2015, Japan established a greenhouse gas reduction target of 25% compared to 2013, and registered it. Although the goal for achieving a low-carbon society has been completed by setting energy saving target and energy mix policy, how to realize it during the progress of power system innovation is important and it is not easy. As the energy policy, the following are important: (1) steady realization of energy saving, (2) cost reduction and balancing of introduction of renewable energy, (3) clean use of fossil fuels, and (4) ensuring the safety of nuclear power and steady restart. This study discusses what will be made for each item, and what will be needed. To make Japan's efforts toward a low-carbon society a reality, the securement of zero-emission power sources of 44% is indispensable, and 20% to 22% (a little less of half of it) is expectedly depending on nuclear power. With the Paris Agreement at COP 21, the buildup of a low-carbon society in Japan is now an urgent issue. However, there are various hurdles for realizing it, and in addition, the system innovation of electric power business has entered a full-fledged stage, making the task further complicated. (A.O.)

  11. Low carbon technology performance vs infrastructure vulnerability: analysis through the local and global properties space.

    Science.gov (United States)

    Dawson, David A; Purnell, Phil; Roelich, Katy; Busch, Jonathan; Steinberger, Julia K

    2014-11-04

    Renewable energy technologies, necessary for low-carbon infrastructure networks, are being adopted to help reduce fossil fuel dependence and meet carbon mitigation targets. The evolution of these technologies has progressed based on the enhancement of technology-specific performance criteria, without explicitly considering the wider system (global) impacts. This paper presents a methodology for simultaneously assessing local (technology) and global (infrastructure) performance, allowing key technological interventions to be evaluated with respect to their effect on the vulnerability of wider infrastructure systems. We use exposure of low carbon infrastructure to critical material supply disruption (criticality) to demonstrate the methodology. A series of local performance changes are analyzed; and by extension of this approach, a method for assessing the combined criticality of multiple materials for one specific technology is proposed. Via a case study of wind turbines at both the material (magnets) and technology (turbine generators) levels, we demonstrate that analysis of a given intervention at different levels can lead to differing conclusions regarding the effect on vulnerability. Infrastructure design decisions should take a systemic approach; without these multilevel considerations, strategic goals aimed to help meet low-carbon targets, that is, through long-term infrastructure transitions, could be significantly jeopardized.

  12. Strategies for Low-Carbon Green Growth and Urban Management in Korea

    Directory of Open Access Journals (Sweden)

    Jichung Yang

    Full Text Available ABSTRACT: National policies and strategies for low-carbon green growth in Korea are reviewed in this study. Providing standards and guidelines for urban comprehensive planning and management plans is necessary so that the series of plans can deal with possible effects from climate changes. Urban planning guidelines for management and improvements to achieve low carbon green growth were set up and implemented, focusing on institutional and regulatory foundations. These deal with climate change influences on urban planning, reduction of green house gas emissions and elevation of energy efficiency based on plans of land use units. In the case of Seoul city, transit-oriented compact development, public transportation-oriented structure, green space expansion, and pleasant living spaces are implemented in relation to urban structure and land use. We should suggest systematic and comprehensive countermeasures against greenhouse gas emissions and climate changes in terms of spatial structure, transportation systems, natural resource conservation, environment management, energy and open spaces. For the Seoul mega-city, plans show the capabilities of the policy department including many policy tools. Reflecting smart city, ubiquitous city, and U-Eco city concepts and human behavior, we should move towards increasing efficiency and maintaining sustainable economic growth. KEYWORDS: Low-carbon green growth, urban management, Korea, Seoul

  13. Research on Price of Railway Freight Based on Low-Carbon Economy

    Directory of Open Access Journals (Sweden)

    Fenling Feng

    2016-01-01

    Full Text Available Transportation is one of the major energy consumption and carbon emission industries. Railway transport is a typical low-carbon transport. To accelerate the green low-carbon transportation development and improve the railway market share, this paper defines the concept of carbon saving profit to study the price of railway freight after the government functions were separated from railway enterprise management. First, taking full account of market factors and on the principle of utility maximization and maximum likelihood method, the sharing ratio model of transportation modes is established. Then consideration is given to both the profit of railway enterprises and social benefits, and income maximization model of railway freight based on low-carbon economy is established. The model can scientifically guide the transportation users who prefer to use resource-saving and environmental-friendly transportation modes, optimize transportation structure, and comprehensively improve the efficiency of transportation system. Finally, case analysis is conducted to verify the rationality and validity of the model, and reference for the rail freight pricing is provided.

  14. Towards low carbon business park energy systems: Classification of techno-economic energy models

    International Nuclear Information System (INIS)

    Timmerman, Jonas; Vandevelde, Lieven; Van Eetvelde, Greet

    2014-01-01

    To mitigate climate destabilisation, human-induced greenhouse gas emissions urgently need to be curbed. A major share of these emissions originates from the industry and energy sectors. Hence, a low carbon shift in industrial and business park energy systems is called for. Low carbon business parks minimise energy-related carbon dioxide emissions by maximal exploitation of local renewable energy production, enhanced energy efficiency, and inter-firm heat exchange, combined in a collective energy system. The holistic approach of techno-economic energy models facilitates the design of such systems, while yielding an optimal trade-off between energetic, economic and environmental performances. However, no models custom-tailored for industrial park energy systems are detected in literature. In this paper, existing energy model classifications are scanned for adequate model characteristics and accordingly, a confined number of models are selected and described. Subsequently, a practical typology is proposed, existing of energy system evolution, optimisation, simulation, accounting and integration models, and key model features are compared. Finally, important features for a business park energy model are identified. - Highlights: • A holistic perspective on (low carbon) business park energy systems is introduced. • A new categorisation of techno-economic energy models is proposed. • Model characteristics are described per model category. • Essential model features for business park energy system modelling are identified. • A strategy towards a techno-economic energy model for business parks is proposed

  15. Low carbon renewable natural gas production from coalbeds and implications for carbon capture and storage.

    Science.gov (United States)

    Huang, Zaixing; Sednek, Christine; Urynowicz, Michael A; Guo, Hongguang; Wang, Qiurong; Fallgren, Paul; Jin, Song; Jin, Yan; Igwe, Uche; Li, Shengpin

    2017-09-18

    Isotopic studies have shown that many of the world's coalbed natural gas plays are secondary biogenic in origin, suggesting a potential for gas regeneration through enhanced microbial activities. The generation of biogas through biostimulation and bioaugmentation is limited to the bioavailability of coal-derived compounds and is considered carbon positive. Here we show that plant-derived carbohydrates can be used as alternative substrates for gas generation by the indigenous coal seam microorganisms. The results suggest that coalbeds can act as natural geobioreactors to produce low carbon renewable natural gas, which can be considered carbon neutral, or perhaps even carbon negative depending on the amount of carbon sequestered within the coal. In addition, coal bioavailability is no longer a limiting factor. This approach has the potential of bridging the gap between fossil fuels and renewable energy by utilizing existing coalbed natural gas infrastructure to produce low carbon renewable natural gas and reducing global warming.Coalbeds produce natural gas, which has been observed to be enhanced by in situ microbes. Here, the authors add plant-derived carbohydrates (monosaccharides) to coal seams to be converted by indigenous microbes into natural gas, thus demonstrating a potential low carbon renewable natural gas resource.

  16. Ecological network analysis for a low-carbon and high-tech industrial park.

    Science.gov (United States)

    Lu, Yi; Su, Meirong; Liu, Gengyuan; Che