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Sample records for carbon steel exposed

  1. Microbiologically Influenced Corrosion of Carbon Steel Exposed to Biodiesel

    Directory of Open Access Journals (Sweden)

    S. Malarvizhi

    2016-01-01

    Full Text Available Environmental concerns over worsening air pollution problems caused by emissions from vehicles and depletion of fossil fuels have forced us to seek fuels such as biodiesel which can supplement petrofuels. Biodiesels have the ability to retain water and provide a conducive environment for microbiologically influenced corrosion (MIC which may cause difficulties during transportation, storage, and their use. This paper analyses the influence of bacteria on the corrosivity of biodiesel obtained from Jatropha curcas on carbon steel using mass loss method. Carbon steel showed the highest corrosion rates in B100 (100% biodiesel both in the presence and in absence of bacteria. The surface analysis of the metal was carried out using SEM.

  2. Mechanism of Pitting Corrosion Prevention by Nitrite in Carbon Steel Exposed to Dilute Salt Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Philip E. Zapp; John W. Van Zee

    2002-02-01

    The research has developed a broad fundamental understanding of the inhibition action of nitrite ions in preventing nitrate pitting corrosion of carbon steel tanks containing high-level radioactive waste. This fundamental understanding can be applied to specific situations during waste removal for permanent disposition and waste tank closure to ensure that the tanks are maintained safely. The results of the research provide the insight necessary to develop solutions that prevent further degradation.

  3. Microbial corrosion and cracking in steel. Fundamental studies on the electrochemical behaviour of carbon steel exposed in sulphide and sulphate-reducing environments

    Energy Technology Data Exchange (ETDEWEB)

    Rischel Hilbert, Lisbeth

    1998-08-01

    The aim of the report is to give a fundamental understanding of the response of different electrochemical techniques on carbon steel in a sulphide environment as well as in a biologically active sulphate-reducing environment (SRB). This will form the basis for further studies and for recommendations in regards to electrochemical monitoring of MIC. The work presented here and further studies are also planned to lead to a Ph.D. thesis on `MIC monitoring based on mechanisms on corrosion`. The results of laboratory experiments conducted in the period 1995 to 1997 are summarised. Conclusions will be based on results from the entire 3 year period, but only selected experimental data primarily from the latest experiments will be presented in detail here. Microbial corrosion of carbon steel under influence of sulphate-reducing bacteria (SRB) is characterised by the formation of both biofilm and corrosion products (ferrous sulphides) on the metal surface. Experiments have been conducted on carbon steel exposed in near neutral (pH 6 to 8.5) saline hydrogen sulphide environment (0 to 100 mg/l total dissolved sulphide) for a period of 14 days. Furthermore coupons have been exposed in a bioreactor for a period of up to 120 days in sulphide-producing environment controlled by biological activity of (SRB). (au)

  4. Vapor Corrosion Response of Low Carbon Steel Exposed to Simulated High Level Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B

    2006-01-26

    A program to resolve the issues associated with potential vapor space corrosion and liquid/air interface corrosion in the Type III high level waste tanks is in place. The objective of the program is to develop understanding of vapor space (VSC) and liquid/air interface (LAIC) corrosion to ensure a defensible technical basis to provide accurate corrosion evaluations with regard to vapor space and liquid/air interface corrosion. The results of the FY05 experiments are presented here. The experiments are an extension of the previous research on the corrosion of tank steel exposed to simple solutions to corrosion of the steel when exposed to complex high level waste simulants. The testing suggested that decanting and the consequent residual species on the tank wall is the predominant source of surface chemistry on the tank wall. The laboratory testing has shown that at the boundary conditions of the chemistry control program for solutions greater than 1M NaNO{sub 3}{sup -}. Minor and isolated pitting is possible within crevices in the vapor space of the tanks that contain stagnant dilute solution for an extended period of time, specifically when residues are left on the tank wall during decanting. Liquid/air interfacial corrosion is possible in dilute stagnant solutions, particularly with high concentrations of chloride. The experimental results indicate that Tank 50 would be most susceptible to the potential for liquid/air interfacial corrosion or vapor space corrosion, with Tank 49 and 41 following, since these tanks are nearest to the chemistry control boundary conditions. The testing continues to show that the combination of well-inhibited solutions and mill-scale sufficiently protect against pitting in the Type III tanks.

  5. Fundamental Studies on the Electrochemical Behaviour of Carbon Steel Exposed in Sulphide and Sulphate-Reducing Environments

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    The aim of the report is to give a fundamental understanding of the response of different electrochemical techniques on carbon steel in a sulphide environment as well as in a biologically active sulphate-reducing environment (SRB). This will form the basis for further studies and for recommendati...

  6. Ultrahigh Carbon Steels

    Science.gov (United States)

    Sherby, O. D.; Oyama, T.; Kum, D. W.; Walser, B.; Wadsworth, J.

    1985-06-01

    Recent studies and results on ultrahigh carbon (UHC) steels suggest that major development efforts on these steels are timely and that programs to evaluate prototype structural components should be initiated. These recent results include: the development of economical processing techniques incorporating a divorced eutectoid transformation, the improvement of room temperature strength and ductility by heat treatment, the enhancement of superplastic properties through dilute alloying with silicon, and the attainment of exceptional notch impact strength in laminated UHC steel composites manufactured through solid state bonding. The unique mechanical properties achieved in UHC steels are due to the presence of micron-size fer-rite grains and ultrafine spheroidized carbides.

  7. Tensile Strength and Oxide Analysis of Carbon Steel in Concrete Exposed in Atmospheric Environment for 53 Years

    Institute of Scientific and Technical Information of China (English)

    FENG Xingguo; LU Xiangyu; ZUO Yu; CHEN Da; SU Xiaodong

    2015-01-01

    The tensile strength of a corroded rebar in a 53-year-old concrete structure was studied. The microstructure of the metallic substrate, the fracture surface, and the corrosion product layers were investigated. Metallographic observation results showed that the carbon steel was constituted of ferrite and some pearlite. The tensile test results indicated that the corroded rebar presented low strength and elongation. In addition, the fracture surface of the rebar in the tensile test displayed dimple fracture behavior. The Raman spectroscopy results indicated that corrosion products at the general corrosion zone were obviously different from those at the localized corrosion zone. The rust layer at the general corrosion zone was composed of goethite (α-FeOOH), magnetite (Fe3O4), and hematite (α-Fe2O3), while that of the pitting zone was made of feroxyhyte (δ-FeOOH), goethite (α-FeOOH), and hematite (α-Fe2O3). However, the general tendencies that the corrosion products were constituted of a mix of oxides and hydroxides, the oxides mainly existed in the internal part and the hydroxides more presented in the external layer were observed.

  8. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  9. Formation of Biofilms and Biocorrosion on AISI-1020 Carbon Steel Exposed to Aqueous Systems Containing Different Concentrations of a Diesel/Biodiesel Mixture

    Directory of Open Access Journals (Sweden)

    Ivanilda Ramos de Melo

    2011-01-01

    Full Text Available Environmental and economic concerns accelerated biofuels research and industrial production. Many countries have been using diesel and biodiesel blends as fuels justifying research on biofilms formation and metals corrosion. Cylinders made of AISI-1020 carbon steel with an exposed area of 1587 mm2, water, and water associated with B3 fuel (diesel/biodiesel blend at 97 : 3 v/v were used.The formation of biofilms was detected, and biocorrosion was detected on AISI-1020. The results showed a variation in sessile microflora during the experiments. In the biofilms, a significant concentration of aerobic, anaerobic, IOB, Pseudomonas aeruginosa, and sulfate-reducing bacteria was observed. The corrosion rates varied between 0.45±0.01 and 0.12±0.01 mm/year, depending on the experimental conditions. The main corrosion products identified were various forms of FeOOH, magnetite, and all forms of FexSy. In systems where there were high levels of sulfate reducing bacteria, corrosion pits were observed. In addition, the aliphatic hydrocarbons present in the fluid containing 10% B3 were totally degraded.

  10. History of ultrahigh carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  11. Microbially induced corrosion of carbon steel in deep groundwater environment

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    Pauliina eRajala

    2015-07-01

    Full Text Available The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland for periods of three and eight months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel.

  12. Ultrahigh Carbon Steel.

    Science.gov (United States)

    1984-10-01

    Steels have been utilized to prepare compacted powders of white cast iron (2 to 3%C) which exhibit superplastic be- havior at 650 0C and which are ductile ...strength and ductility than many of these commercially-avail- able steels. In particular, austempered fine-grained UHC steels exhibit good co7,binations of... Ductility of Rapidly Solidified White Cast Irons ", Powd. Metall., 26 (1983), pp. 155-160. (29) L. E. Eiselstein, 0. A. Ruano, J. Wadsworth, and 0. D

  13. Electrochemical Studies of Nitrate-Induced Pitting in Carbon Steel

    Energy Technology Data Exchange (ETDEWEB)

    Zapp, P.E.

    1998-12-07

    The phenomenon of pitting in carbon steel exposed to alkaline solutions of nitrate and chloride was studied with the cyclic potentiodynamic polarization technique. Open-circuit and pitting potentials were measured on specimens of ASTM A537 carbon steel in pH 9.73 salt solutions at 40 degrees Celsius, with and without the inhibiting nitrite ion present. Nitrate is not so aggressive a pitting agent as is chloride. Both nitrate and chloride did induce passive breakdown and pitting in nitrite-free solutions, but the carbon steel retained passivity in solutions with 0.11-M nitrite even at a nitrate concentration of 2.2 M.

  14. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  15. Studies of stainless steel exposed to sandblasting

    Directory of Open Access Journals (Sweden)

    Horodek Paweł

    2015-12-01

    Full Text Available The influence of sandblasting on surface and subsurface of stainless steel is investigated using variable energy positron beam (VEP, positron annihilation spectroscopy (PAS, scanning electron microscopy (SEM, and atomic force microscopy (AFM. Samples of stainless steel were blasted using 110 μm particles of Al2O3 under different pressure and time duration. In the case of sandblasting for 90 s, the reduction of positron diffusion length depending on the applied pressure was observed. Sandblasting during 30 s leads only to the reduction of positron diffusion length to about 60 nm for all samples. Positron lifetimes close to 170 ps measured using positrons emitted directly from the source point to the presence of vacancies on the dislocation lines. SEM and AFM images show that surface roughness depends rather on pressure of sandblasting than time of exposition.

  16. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  17. Microbial corrosion of carbon steel by sulfate-reducing bacteria:

    DEFF Research Database (Denmark)

    Nielsen, Lars Vendelbo; Hilbert, Lisbeth Rischel

    1997-01-01

    Electrochemical measurements (EIS and DC-polarisation curves) have been conducted on carbon steel coupons exposed in SRB-active environments. Results from EIS measurements show that very large interfacial capacities are found in such systems, and consequently high capacitive currents...... for a misleading conclusion that increasing corrosion rates are caused by cathodic depolarisation in SRB-active environments....

  18. Plain carbon steel bipolar plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    WANG Jianli; SUN Juncai; TIAN Rujin; XU Jing

    2006-01-01

    Bipolar plates are a multifunctional component of PEMFC. Comparing with the machined graphite and stainless steels, the plain carbon steel is a very cheap commercial metal material. In this paper, the possibility of applying the plain carbon steels in the bipolar plate for PEMFC was exploited. In order to improve the corrosion resistance of the low carbon steel in the PEMFCs' environments,two surface modification processes was developed and then the electrochemical performances and interfacial contact resistance (ICR) of the surface modified plate of plain carbon steel were investigated. The results show that the surface modified steel plates have good corrosion resistance and relatively low contact resistance, and it may be a candidate material as bipolar plate of PEMFC.

  19. Iron cycling at corroding carbon steel surfaces.

    Science.gov (United States)

    Lee, Jason S; McBeth, Joyce M; Ray, Richard I; Little, Brenda J; Emerson, David

    2013-01-01

    Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media.

  20. Ultrahigh Ductility, High-Carbon Martensitic Steel

    Science.gov (United States)

    Qin, Shengwei; Liu, Yu; Hao, Qingguo; Zuo, Xunwei; Rong, Yonghua; Chen, Nailu

    2016-10-01

    Based on the proposed design idea of the anti-transformation-induced plasticity effect, both the additions of the Nb element and pretreatment of the normalization process as a novel quenching-partitioning-tempering (Q-P-T) were designed for Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb hot-rolled steel. This high-carbon Q-P-T martensitic steel exhibits a tensile strength of 1890 MPa and elongation of 29 pct accompanied by the excellent product of tensile and elongation of 55 GPa pct. The origin of ultrahigh ductility for high-carbon Q-P-T martensitic steel is revealed from two aspects: one is the softening of martensitic matrix due to both the depletion of carbon in the matensitic matrix during the Q-P-T process by partitioning of carbon from supersaturated martensite to retained austenite and the reduction of the dislocation density in a martensitic matrix by dislocation absorption by retained austenite effect during deformation, which significantly enhances the deformation ability of martensitic matrix; another is the high mechanical stability of considerable carbon-enriched retained austenite, which effectively reduces the formation of brittle twin-type martensite. This work verifies the correctness of the design idea of the anti-TRIP effect and makes the third-generation advanced high-strength steels extend to the field of high-carbon steels from low- and medium-carbon steels.

  1. Atmospheric Corrosion of Q235 Carbon Steel and Q450 Weathering Steel in Turpan,China

    Institute of Scientific and Technical Information of China (English)

    Qiang YU; Chao-fang DONG; Yue-hua FANG; Kui XIAO; Chun-yun GUO; Gang HE; Xiao-gang LI

    2016-01-01

    Q235 carbon steel and Q450 weathering steel were exposed to the hot and dry environment of Turpan, China for three years.The corrosion rates of both steels were calculated and compared.The morphologies of the rust layer products were observed by optical microscopy and scanning electron microscopy.Analyses of the rust layers were performed by X-ray photoelectron spectroscopy,X-ray powder diffraction,and Raman spectroscopy,and anal-ysis results indicate that the compositions of rust are main iron rich oxide such as FeOOH,Fe3 O4 ,and Fe2 O3 .The iron oxide layer content proportion was calculated through a semi-quantitative algorithm.The resistance elements (Cr,Ni,and Cu)enhanced the resistance properties of the Q450 weathering steel matrix.Moreover,the resistance elements increased the proportion of goethite crystals in the corroded rust layer.

  2. Atmospheric corrosion of carbon steel resulting from short term exposures

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, R.; Cook, D.C.; Perez, T.; Reyes, J. [Department of Physics, Old Dominion University, Norfolk, VA 23529 (United States)

    1998-12-31

    The study of corrosion products from short term atmospheric exposures of carbon steel, is very important to understand the processes that lead to corrosion of steels, and ultimately improve the performance of such steel in highly corrosive environments. Many regions along the Gulf of Mexico have extremely corrosive environments due to high mean annual temperature, humidity, time-of-wetness and every high atmospheric pollutants. The process the formation of corrosion products resulting from short term exposure of carbon steel, both as a function of environmental conditions and exposure time, has been investigated. Two sets of coupons were exposed at marine and marine locations, in Campeche, Mexico. Each set was exposed between 1 and 12 months to study the corrosion as a function of time. During the exposure periods, the relative humidity, rainfall, mean temperature, wind speed and wind direction were monitored along with the chloride and sulfur dioxide concentrations in the air. The corroded coupons were analyzed by Moessbauer, Raman, Infrared spectroscopies and X-ray diffraction in order to completely identify the oxides and map their location in the corrosion coating. Scattering and transmission Moessbauer analysis showed some layering of the oxides with lepidocrocite and akaganeite closer to the surface. The fraction of akaganeite phase increased at sites with higher chloride concentrations. A detailed analysis on the development of the oxide phases as a function of exposure time and environmental conditions will be presented. (Author)

  3. EIS Response of MIC on Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Maahn, Ernst

    1998-01-01

    Abstract Microbially influenced corrosion of carbon steel under sulphate reducing (sulphide-producing) bacterial activity (SRB) results in the formation of both ferrous sulphides as well as biofilm on the metal surface. The electrochemical characteristics of the ferrous sulphide/steel interface...... as compared to the biofilm/ferrous sulphide/steel interface has been studied with EIS, DC polarisations (Tafel, LPR) and a potentiostatic step technique. The electrochemical response is related to a threshold sulphide concentration above which very characteristic changes such as indications of finite...... response from the metal surface....

  4. Anticorrosive Influence of Acetobacter aceti Biofilms on Carbon Steel

    Science.gov (United States)

    France, Danielle Cook

    2016-09-01

    Microbiologically influenced corrosion (MIC) of carbon steel infrastructure is an emerging environmental and cost issue for the ethanol fuel industry, yet its examination lacks rigorous quantification of microbiological parameters that could reveal effective intervention strategies. To quantitatively characterize the effect of cell concentration on MIC of carbon steel, numbers of bacteria exposed to test coupons were systematically controlled to span four orders of magnitude throughout a seven-day test. The bacterium studied, Acetobacter aceti, has been found in ethanol fuel environments and can convert ethanol to the corrosive species acetic acid. A. aceti biofilms formed during the test were qualitatively evaluated with fluorescence microscopy, and steel surfaces were characterized by scanning electron microscopy. During exposure, biofilms developed more quickly, and test reactor pH decreased at a faster rate, when cell exposure was higher. Resulting corrosion rates, however, were inversely proportional to cell exposure, indicating that A. aceti biofilms are able to protect carbon steel surfaces from corrosion. This is a novel demonstration of corrosion inhibition by an acid-producing bacterium that occurs naturally in corrosive environments. Mitigation techniques for MIC that harness the power of microbial communities have the potential to be scalable, inexpensive, and green solutions to industrial problems.

  5. Modification in the Microstructure of Mod. 9Cr-1Mo Ferritic Martensitic Steel Exposed to Sodium

    Science.gov (United States)

    Prasanthi, T. N.; Sudha, Cheruvathur; Paul, V. Thomas; Bharasi, N. Sivai; Saroja, S.; Vijayalakshmi, M.

    2014-09-01

    Mod. 9Cr-1Mo is used as the structural material in the steam generator circuit of liquid metal-cooled fast breeder reactors. Microstructural modifications on the surface of this steel are investigated after exposing to flowing sodium at a temperature of 798 K (525 °C) for 16000 hours. Sodium exposure results in the carburization of the ferritic steel up to a depth of ~218 µm from the surface. Electron microprobe analysis revealed the existence of two separate zones with appreciable difference in microchemistry within the carburized layer. Differences in the type, morphology, volume fraction, and microchemistry of the carbides present in the two zones are investigated using analytical transmission electron microscopy. Formation of separate zones within the carburized layer is understood as a combined effect of leaching, diffusion of the alloying elements, and thermal aging. Chromium concentration on the surface in the α-phase suggested possible degradation in the corrosion resistance of the steel. Further, concentration-dependent diffusivities for carbon are determined in the base material and carburized zones using Hall's and den Broeder's methods, respectively. These are given as inputs for simulating the concentration profiles for carbon using numerical computation technique based on finite difference method. Predicted thickness of the carburized zone agrees reasonably well with that of experiment.

  6. Marine atmospheric corrosion of carbon steels

    Directory of Open Access Journals (Sweden)

    Morcillo, Manuel

    2015-06-01

    Full Text Available Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a environmental conditions necessary for akaganeite formation; (b characterisation of akaganeite in the corrosion products formed; (c corrosion mechanisms of carbon steel in marine atmospheres; (d exfoliation of rust layers formed in highly aggressive marine atmospheres; (e long-term corrosion rate prediction; and (f behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camariñas, Galicia in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM/energy dispersive spectrometry (EDS, X-ray diffraction (XRD, Mössbauer spectroscopy and SEM/μRaman spectroscopy.La investigación fundamental en corrosión atmosférica marina de aceros al carbono es un campo científico relativamente joven que presenta grandes lagunas de conocimiento. La formación de akaganeíta en los productos de corrosión que se forman sobre el acero cuando se expone a atmósferas marinas conduce a un incremento notable de la velocidad de corrosión. En el trabajo se abordan las siguientes cuestiones: (a condiciones ambientales necesarias para la formación de akaganeíta, (b caracterización de la akaganeíta en los productos de corrosión formados, (c mecanismos de corrosión del acero al carbono en atmósferas marinas, (d exfoliación de las capas de herrumbre formadas en atmósferas marinas muy agresivas, (e predicción de la velocidad de corrosión a largo plazo, y (f comportamiento de aceros patinables. La

  7. Ten years of Toarcian argillite - carbon steel in situ interaction

    Energy Technology Data Exchange (ETDEWEB)

    Dauzeres, Alexandre [IRSN, PRP-DGE/SRTG/LETIS, BP 17, 92262 Fontenay-aux-Roses cedex (France); Maillet, Anais [IRSN, PRP-DGE/SRTG/LETIS, BP 17, 92262 Fontenay-aux-Roses cedex (France); UMR CNRS 7285, IC2MP, Batiment B35 - 5, avenue Albert Turpain, 86022 Poitiers cedex (France); Gaudin, Anne [UMR CNRS 6112, LPGN, 2 rue de la Houssiniere, BP 92208, 44322 Nantes cedex 3 (France); El Albani, Abderrazak; Vieillard, Philippe [UMR CNRS 7285, IC2MP, Batiment B35 - 5, avenue Albert Turpain, 86022 Poitiers cedex (France)

    2013-07-01

    In situ interaction experiments over periods of 2, 6, and 10 years between Toarcian argillite and carbon steel discs were carried out in the Tournemire Underground Research Laboratory (URL), yielding a dataset of the materials' geochemical evolution under conditions representative of the future geological disposal of high-level long-lived radioactive wastes. The carbon steel discs were exposed to corrosion due to trapped oxygen. The corrosion rates indicate that the oxidizing transient lasted between 2 and 6 years. A systematic dissolution of calcium phases (Ca-smectite sheets in I/S and calcite) was observed in the iron diffusion halos. The iron release induced mineralogical dissolution and precipitation reactions, which partly clogged the argillite porosity. (authors)

  8. Research of Mold Powder for Ultra-Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper explained the mechanism of carbon pickup byultra-low-carbon steels during continuous casting and indicated that the major cause of carbon pickup is the contact of the molten steel with the enriched-carbon layer of the powder. Forming of the enriched-carbon layer is due to the existing of “carbon core”. Accordingly, the measures to reduce the carbon content and amount of the enriched-carbon layer were investigated. A kind of new powder has been developed and successfully used to minimize the carbon pickup by ultra-low carbon steels during continuous casting.

  9. Bimetallic layered castings alloy steelcarbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast processso-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic carbon cast steel, whereas working part (layer is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  10. The distribution of carbon in steels

    Energy Technology Data Exchange (ETDEWEB)

    Nechaev, Yurii S, E-mail: yuri1939@inbox.ru

    2011-05-31

    The nature and characteristics of the way carbon present in steel is distributed spatially and over states may be related to quasichemical 'reactions' that lead to the formation in austenite ({gamma}-Fe-C) and ferrite ({alpha}-Fe-C) of 'carbo-austenite' and 'carbo-ferrite molecules' (nanocomplexes) consisting, along with C atoms, of, respectively, {gamma}-Fe or {alpha}-Fe and of octahedral {gamma}- or {alpha}-interstitials. In this way, various aspects of the quasichemical dissolution and diffusion 'reactions' of carbon in the material can be determined, as can the quasichemical component of the martensite transformation (MT) mechanism in carbon steels. (reviews of topical problems)

  11. Aluminizing Low Carbon Steel at Lower Temperatures

    Institute of Scientific and Technical Information of China (English)

    Xiao Si; Bining Lu; Zhenbo Wang

    2009-01-01

    This study reports the significantly enhanced aluminizing behaviors of a low carbon steel at temperatures far below the austenitizing temperature, with a nanostructured surface layer produced by surface mechanical attrition treatment (SMAT). A much thicker iron aluminide compound layer with a much enhanced growth kinetics of η-Fe2Al5 in the SMAT sample has been observed relative to the coarse-grained steel sample. Compared to the coarse-grained sample, a weakened texture is formed in the aluminide layer in the SMAT sample. The aluminizing kinetics is analyzed in terms of promoted diffusivity and nucleation frequency in the nanostructured surface layer.

  12. MECHANISTIC UNDERSTANDING OF CAUSTIC CRACKING OF CARBON STEELS

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Diaz, B.; Roy, A.

    2009-10-19

    Liquid waste generated by the PUREX process for separation of nuclear materials is concentrated and stored in Type IV single-shell carbon steel tanks at the Savannah River Site (SRS). The Type IV tanks for this waste do not have cooling coils and have not undergone heat treatment to stress-relieve the tanks. After the waste is concentrated by evaporation, it becomes very alkaline and can cause stress corrosion cracking (SCC) and pitting corrosion of the tank materials. SRS has experienced leakage from non-stress-relieved waste tanks constructed of A285 carbon steel and pitting of A212 carbon steel tanks in the vapor space. An investigation of tank materials has been undertaken at SRS to develop a basic understanding of caustic SCC of A285 and A212 grade carbon steels exposed to aqueous solutions, primarily containing sodium hydroxide (NaOH), sodium nitrate (NaNO{sub 3}), and sodium nitrite (NaNO{sub 2}) at temperatures relevant to the operating conditions of both the F and H area plants. This report presents the results of this corrosion testing program. Electrochemical tests were designed using unstressed coupons in a simulated tank environment. The purpose of this testing was to determine the corrosion susceptibility of the tank materials as a function of chemical concentration, pH, and temperature. A285 and A516 (simulates A212 carbon steel) coupons were used to investigate differences in the corrosion of these carbon steels. Electrochemical testing included measurement of the corrosion potential and polarization resistance as well as cyclic potentiodynamic polarization (CPP) testing of coupons. From the CPP experiments, corrosion characteristics were determined including: corrosion potential (E{sub corr}), pitting or breakdown potential (E{sub pit}), and repassivation potential (E{sub prot}). CPP results showed no indications of localized corrosion, such as pitting, and all samples showed the formation of a stable passive layer as evidenced by the positive

  13. Effect of steel surface conditions on reinforcing steel corrosion in concrete exposed to marine environments

    Directory of Open Access Journals (Sweden)

    Anzola, E.

    2005-09-01

    Full Text Available Laboratory methods and experimental tests were deployed in the present study to evaluate corrosion in reinforced concrete exposed to marine environments. Reinforcing steel exhibiting two different surface conditions prior to embedment in concrete were studied, one the one hand to assess the electrochemical behaviour of the bars during exposure of the concrete specimens to a simulated marine environment, and on the other to determine the strength of the steel/concrete bond. The reinforced concrete specimens prepared were adapted as required for electrochemical potential and corrosion rate testing. A total of 56 7x15-cm cylindrical specimens containing 3/8" steel rods anchored at a depth of 11.5 cm were made to evaluate the steel / concrete bond and exposed to a natural marine environment for 28 or 190 days prior to testing. All the specimens were made with ready-mixed concrete. It may be concluded from the results of the corrosion tests on reinforcing steel with different surface conditions that the oxide initially covering the bars was dissolved and the steel passivated by the alkalinity in the concrete. The chief finding of the bonding study was that the layer of oxide formed in pre-embedment steel deterioration contributed to establishing a better bond.

    En el contexto de esta investigación, se tomaron en consideración métodos y ensayos experimentales de laboratorio, que permiten hacer una evaluación de la corrosión del hormigón armado expuesto en ambientes marinos. Por una parte se evaluó el comportamiento electroquímico de dos condiciones de estados superficiales del acero embebido en el hormigón, exponiéndolo en un ambiente marino simulado y, por otra parte, se estudió la adherencia entre el acero y el hormigón, con los mismos estados superficiales usados para la evaluación electroquímica. Las probetas se fabricaron de hormigón con acero de refuerzo en su interior, adecuándolas para realizar los ensayos de potenciales

  14. Integrating Steel Production with Mineral Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Klaus Lackner; Paul Doby; Tuncel Yegulalp; Samuel Krevor; Christopher Graves

    2008-05-01

    The objectives of the project were (i) to develop a combination iron oxide production and carbon sequestration plant that will use serpentine ores as the source of iron and the extraction tailings as the storage element for CO2 disposal, (ii) the identification of locations within the US where this process may be implemented and (iii) to create a standardized process to characterize the serpentine deposits in terms of carbon disposal capacity and iron and steel production capacity. The first objective was not accomplished. The research failed to identify a technique to accelerate direct aqueous mineral carbonation, the limiting step in the integration of steel production and carbon sequestration. Objective (ii) was accomplished. It was found that the sequestration potential of the ultramafic resource surfaces in the US and Puerto Rico is approximately 4,647 Gt of CO2 or over 500 years of current US production of CO2. Lastly, a computer model was developed to investigate the impact of various system parameters (recoveries and efficiencies and capacities of different system components) and serpentinite quality as well as incorporation of CO2 from sources outside the steel industry.

  15. Nanostructure-based Processes at the Carbonizing Steels

    Directory of Open Access Journals (Sweden)

    L.I. Roslyakova

    2015-12-01

    Full Text Available The studies of nanostructure-based processes carburizing steels showed that oxidizing atmosphere when carburizing steel contains along with carbon dioxide (CO2 + C = 2CO molecular and atmospheric oxygen (O2 + 2C = 2CO; O + C = CO released from the carbonate ВаСОз during its thermal dissociation. Intensive formation of CO provides high carbonizing ability of carbonate-soot coating and steel.

  16. Processing of Ultralow Carbon Pipeline Steels with Acicular Ferrite

    Institute of Scientific and Technical Information of China (English)

    Furen XIAO; Mingchun ZHAO; Yiyin SHAN; Bo LIAO; Ke YANG

    2004-01-01

    Acicular ferrite microstructure was achieved for an ultralow carbon pipeline steel through the improved thermomechanical control process (TMCP), which was based on the transformation process of deformed austenite of steel.Compared with commercial pipeline steels, the experimental ultralow carbon pipeline steel possessed the satisfied strength and toughness behaviors under the current improved TMCP, although it contained only approximately 0.025% C, which should mainly be attributed to the microstructural characteristics of acicular ferrite.

  17. Steel slag carbonation in a flow-through reactor system: the role of fluid-flux.

    Science.gov (United States)

    Berryman, Eleanor J; Williams-Jones, Anthony E; Migdisov, Artashes A

    2015-01-01

    Steel production is currently the largest industrial source of atmospheric CO2. As annual steel production continues to grow, the need for effective methods of reducing its carbon footprint increases correspondingly. The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace (BOF) steel production, in particular its major constituent, larnite {Ca2SiO4}, which is a structural analogue of olivine {(MgFe)2SiO4}, the main mineral subjected to natural carbonation in peridotites, offers the potential to offset some of these emissions. However, the controls on the nature and efficiency of steel slag carbonation are yet to be completely understood. Experiments were conducted exposing steel slag grains to a CO2-H2O mixture in both batch and flow-through reactors to investigate the impact of temperature, fluid flux, and reaction gradient on the dissolution and carbonation of steel slag. The results of these experiments show that dissolution and carbonation of BOF steel slag are more efficient in a flow-through reactor than in the batch reactors used in most previous studies. Moreover, they show that fluid flux needs to be optimized in addition to grain size, pressure, and temperature, in order to maximize the efficiency of carbonation. Based on these results, a two-stage reactor consisting of a high and a low fluid-flux chamber is proposed for CO2 sequestration by steel slag carbonation, allowing dissolution of the slag and precipitation of calcium carbonate to occur within a single flow-through system.

  18. Comparative Structural Strength Research of Hardened Carbon Steel and Hot-Rolled Alloy Steel

    Science.gov (United States)

    Bogomolov, A. V.; Zhakupov, A. N.; Kanayev, A. T.; Sikach, I. A.; Tugumov, K. K.

    2016-08-01

    Experiments on quantitative evaluation of fatigue strength showed that St5ps and St5sp carbon steels with A400 strength class can be fully applied for erection of constructions and buildings having cyclical loads during operation. Study of corrosion resistance of hardened carbon steel in comparison with hot-rolled alloy steel consists in difference in structures and hence, difference in intensity of electric and chemical processes featuring presence of steel in concrete. Structure of St5sp steel with A400 strength class in surface area has significantly less corrosion rate than ferritic-perlitic structure of 35GS steel with A400 strength class.

  19. Friction stir processing on carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, Sergei Yu., E-mail: tsy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Melnikov, Alexander G., E-mail: melnikov-ag@tpu.ru [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Rubtsov, Valery E., E-mail: rvy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)

    2014-11-14

    Friction stir processing of medium carbon steel samples has been carried out using a milling machine and tools made of cemented tungsten carbide. Samples have been machined from 40 and 40X steels. The tools have been made in the shape of 5×5×1.5 mm and 3×3×1.5 mm tetrahedrons. The microstructure of stirred zone has been obtained using the smaller tool and consists of fine recrystallized 2-3 μm grains, whereas the larger tool has produced the 'onion-like' structures comprising hard quenched 'white' 500-600 MPa layers with 300-350 MPa interlayers of bainite needles. The mean values of wear intensity obtained after measuring the wear scar width were 0.02 mm/m and 0.001 mm/m for non-processed and processed samples, respectively.

  20. Corrosion Behaviors of Steel A3 Exposed to Thiobacillus Ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Jianhua LIU; Xin LIANG; Songmei LI

    2008-01-01

    The corrosion behaviors of steel A3 in synergistic action of Thiobacillus ferrooxidans (T.f) and electrochemically accelerated corrosion were studied by electrochemical, microbiology and surface analysis methods. The open circuit potential (Eocp) and electrochemical impedance spectroscopy (EIS) of the steel A3 electrodes were measured in leathen culture medium without and with T.f (simply called T.f solution in the following paper)in immersion electrode way at the time of the 2nd, 5th, 10th, 20th and 30th days, respectively. It was found that Eocp of the electrode for immersion in leathen culture medium shifted negatively with the immersion time while that for immersion in T.f solutions shifted negatively, then positively and finally negatively. On the 20th day, the corrosion of steel A3 for immersion in culture medium was in pitting initiation stage while that for immersion in T.f solutions was in pitting growth stage. It was found that the corrosion of steel A3 was accelerated by T.f. The morphology of corrosion product of steel A3 immersion in T.f solutions observed through scanning electron microscopy (SEM) transformed from solid globules to tabular plates and to spongy globules and plates.

  1. Crack branching in carbon steel. Fracture mechanisms

    Science.gov (United States)

    Syromyatnikova, A. S.; Alekseev, A. A.; Levin, A. I.; Lyglaev, A. V.

    2010-04-01

    The fracture surfaces of pressure vessels made of carbon steel that form during crack branching propagation are examined by fractography. Crack branching is found to occur at a crack velocity higher than a certain critical value V > V c . In this case, the material volume that is involved in fracture and depends on the elastoplastic properties of the material and the sample width has no time to dissipate the energy released upon crack motion via the damage mechanisms intrinsic in the material under given deformation conditions (in our case, via cracking according to intragranular cleavage).

  2. Control of microbiological corrosion on carbon steel with sodium hypochlorite and biopolymer.

    Science.gov (United States)

    Oliveira, Sara H; Lima, Maria Alice G A; França, Francisca P; Vieira, Magda R S; Silva, Pulkra; Urtiga Filho, Severino L

    2016-07-01

    In the present work, the interaction of a mixture of a biocide, sodium hypochlorite (NaClO), and a biopolymer, xanthan, with carbon steel coupons exposed to seawater in a turbulent flow regime was studied. The cell concentrations, corrosion rates, biomasses, and exopolysaccharides (EPSs) produced on the coupon surfaces with the various treatments were quantified. The corrosion products were evaluated using X-ray diffraction (XRD), and the surfaces of steels were analysed by scanning electron microscopy (SEM). The results indicated that xanthan and the hypochlorite-xanthan mixture reduced the corrosion rate of steel.

  3. Thermoplastic liners for carbon steel pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi, Mauyed S.; AlDossary, Abdullah K. [Saudi Aramco, Dhahran (Saudi Arabia)

    2009-12-19

    Materials selection for pipe and fittings used to convey corrosive fluids has often been a challenge. Traditionally, exotic Corrosion Resistant Alloys (CRA) have been used in corrosive environments despite their high cost. Plastic lined carbon steel piping offers a cost effective alternative to the use of CRAs by eliminating corrosion, significantly reducing the use of toxic chemicals and the heavy metal usually present in CRAs. Thermoplastic Liners offer the combination of corrosion resistance and mechanical strength, which are unachievable with singular materials. Under pressure conditions, the liner is fully supported by the metalwork, while under vacuum conditions, the liner must be thick enough along with venting system to withstand the collapsing forces created by the negative pressure. Plastic liners have been used successfully to line and protect metallic pipelines for many years and have become an indispensable requirement of the oil and gas industry particularly with water injection and hydrocarbon services. In the case of internally corroded pipes, the use of thermoplastic liners for rehabilitation is an option to extend the lifetime of companies' assets, reduce maintenance cost and increase intervals between T and Is. For new construction, plastic liners in carbon steel pipes can compete technically and economically with pipelines of CRA materials and other corrosion inhibition systems. This paper describes various design features, installations of thermoplastic liners in comparison to other corrosion inhibition methods. (author)

  4. Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

    Science.gov (United States)

    Mohamed, Nedal; Boulfiza, Mohamed; Evitts, Richard

    2013-03-01

    Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4™ potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.

  5. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, K.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt t

  6. Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

    Science.gov (United States)

    Johansson, Leena-Sisko; Saastamoinen, Tuomas

    1999-04-01

    We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

  7. Medium carbon vanadium micro alloyed steels for drop forging

    Energy Technology Data Exchange (ETDEWEB)

    Jeszensky, Gabor; Plaut, Ronald Lesley

    1992-12-31

    Growing competitiveness of alternative manufacturing routes requires cost minimization in the production of drop forged components. The authors analyse the potential of medium carbon, vanadium microalloyed steels for drop forging. Laboratory and industrial experiments have been carried out emphasizing deformation and temperature cycles, strain rates and dwell times showing a typical processing path, associated mechanical properties and corresponding microstructures. The steels the required levels of mechanical properties on cooling after forging, eliminating subsequent heat treatment. The machinability of V-microalloyed steels is also improved when compared with plain medium carbon steels. (author) 17 refs., 19 figs., 5 tabs.

  8. The effect of environmental variables on atmospheric corrosion of carbon steel in Shenyang

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; WANG ZhenYao; KE Wei

    2009-01-01

    A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H_2S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.

  9. Fire exposed steel columns with a thermal gradient over the cross-section

    NARCIS (Netherlands)

    Ojeda, O.D.; Maljaars, J.; Abspoel, R.

    2016-01-01

    Thermal gradients often occur in fire exposed structures. This paper considers thermal gradients over the cross-section of steel columns. By means of finite element simulations, the paper demonstrates that these gradients reduce the fiexural buckling resistance of the columns. This is due to the ecc

  10. Comparison between half-cell potential of reinforced concrete exposed to carbon dioxide and chloride environment

    Directory of Open Access Journals (Sweden)

    Somnuk Tangtermsirikul

    2010-10-01

    Full Text Available The objective of this study is to investigate the effect of concrete mix proportion and fly ash on half-cell potential (HCPand corrosion current density (icorr of steel in concrete exposed to different environments. Reinforced concrete specimenswith different fly ash replacement percentages and water to binder ratios (w/b were studied in this paper. The specimenswere subjected to two highly corrosive environments which are chloride and carbon dioxide. HCP and icorr were used tomonitor the corrosion process. Results of this study demonstrate that both HCP and icorr indicated the same tendency,especially for corroded specimens after being exposed to chloride. This means that HCP can be used to inspect corrosion ofsteel due to chloride. In case of carbonation, concrete specimens with fly ash showed more negative potential values thanconcrete without fly ash. However, chloride exposure test exhibited that specimen with higher fly ash replacement corrodedearlier. Moreover, HCP measurement presented different values between concrete exposed to chloride and carbon dioxide.There was an effect of carbonation to increase HCP during the initiation stage. A proper evaluation guideline for steelcorrosion due to carbonation needs to be further studied.

  11. Comparison of Impact Properties for Carbon and Low Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    O.H. Ibrahim

    2011-01-01

    The impact properties of hot rolled carbon steel (used for the manufacture of reinforcement steel bars) and the quenched & tempered (Q&T) low alloy steel (used in the pressure vessel industry) were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200℃. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q&T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the difference in the chemical composition and microstructure for the two steels.

  12. Evolution of Initial Atmospheric Corrosion of Carbon Steel in an Industrial Atmosphere

    Science.gov (United States)

    Pan, Chen; Han, Wei; Wang, Zhenyao; Wang, Chuan; Yu, Guocai

    2016-12-01

    The evolution of initial corrosion of carbon steel exposed to an industrial atmosphere in Shenyang, China, has been investigated by gravimetric, XRD, SEM/EDS and electrochemical techniques. The kinetics of the corrosion process including the acceleration and deceleration processes followed the empirical equation D = At n . The rust formed on the steel surface was bi-layered, comprised of an inner and outer layer. The outer layer was formed within the first 245 days and had lower iron content compared to the inner layer. However, the outer layer disappeared after 307 days of exposure, which is considered to be associated with the depletion of Fe3O4. The evolution of the rust layer formed on the carbon steel has also been discussed.

  13. Steel slag carbonation in a flow-through reactor system:The role of fluid-flux

    Institute of Scientific and Technical Information of China (English)

    Eleanor J.Berryman; Anthony E.Williams-Jones; Artashes A.Migdisov

    2015-01-01

    Steel production is currently the largest industrial source of atmospheric CO2.As annual steel production continues to grow,the need for effective methods of reducing its carbon footprint increases correspondingly.The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace (BOF) steel production,in particular its major constituent,lamite {Ca2SiO4},which is a structural analogue of olivine {(MgFe)2SiO4},the main mineral subjected to natural carbonation in peridotites,offers the potential to offset some of these emissions.However,the controls on the nature and efficiency of steel slag carbonation are yet to be completely understood.Experiments were conducted exposing steel slag grains to a CO2-H2O mixture in both batch and flow-through reactors to investigate the impact of temperature,fluid flux,and reaction gradient on the dissolution and carbonation of steel slag.The results of these experiments show that dissolution and carbonation of BOF steel slag are more efficient in a flow-through reactor than in the batch reactors used in most previous studies.Moreover,they show that fluid flux needs to be optimized in addition to grain size,pressure,and temperature,in order to maximize the efficiency of carbonation.Based on these results,a two-stage reactor consisting of a high and a low fluid-flux chamber is proposed for CO2 sequestration by steel slag carbonation,allowing dissolution of the slag and precipitation of calcium carbonate to occur within a single flow-through system.

  14. Twin structure of the lath martensite in low carbon steel

    Directory of Open Access Journals (Sweden)

    Pan Zhang

    2016-04-01

    Full Text Available It has been well accepted that the martensites in quenched carbon steels exhibit two typical morphologies which are closely dependent on the carbon content, i.e. lath martensite in low carbon steels and lenticular martensite in high carbon steels. Based on conventional belief, the lath martensites in low carbon steels are with high density dislocations as the substructure, in contrast to twin substructure in lenticular high carbon martensite. In the present work, an intensive transmission electron microscopy investigation was made to characterize the microstructures of the lath martensite in a low carbon steel of 0.2 wt%C. It was found that lots of lath martensites consist of twin as their substructure, rather than high density dislocations. In addition, nanoscale precipitates cohering with ferrite matrix were found at the twin interfaces. The orientation relationships between the precipitates and the ferrite matrix are in good agreement with that of primitive hexagonal ω phase in titanium alloys and other bcc metals or alloys.

  15. Microstructural, Structural, and Thermal Characterization of Annealed Carbon Steels

    Science.gov (United States)

    Lara-Guevara, A.; Ortiz-Echeverri, C. J.; Rojas-Rodriguez, I.; Mosquera-Mosquera, J. C.; Ariza-Calderón, H.; Ayala-Garcia, I.; Rodriguez-García, M. E.

    2016-10-01

    As is well known, the metallurgical microstructure of carbon steel is formed by ferrite and pearlite after the annealing heat treatment. When the cooling rate increases, the diffusive process is interrupted causing a change in the metallurgical microstructure which will affect steel properties. The aim of this work was to study thermal, structural, and microstructural properties of annealed carbon steel samples with four different carbon contents. Crystalline structure and crystalline quality were studied by the X-ray diffraction technique, where the full width at half maximum analysis showed that as the carbon content increased, the crystalline quality decreased. The metallurgical microstructure morphology was studied by scanning electron microscopy. The thermal diffusivity and the heat capacity were determined by the photoacoustic technique and by the thermal relaxation method, respectively. The thermal diffusivity and the thermal conductivity decreased as the carbon content increased. The amplitude signal of photothermal radiometry increased as the carbon content increased, while the phase signal of photothermal radiometry did not show significant differences among studied carbon steel types. The photoacoustic technique represents an important alternative in the steel characterization field.

  16. Twin structure of the lath martensite in low carbon steel

    Institute of Scientific and Technical Information of China (English)

    Pan Zhang; Yulin Chen; Wenlong Xiao; Dehai Ping; Xinqing Zhao

    2016-01-01

    It has been well accepted that the martensites in quenched carbon steels exhibit two typical morphol-ogies which are closely dependent on the carbon content, i.e. lath martensite in low carbon steels and lenticular martensite in high carbon steels. Based on conventional belief, the lath martensites in low carbon steels are with high density dislocations as the substructure, in contrast to twin substructure in lenticular high carbon martensite. In the present work, an intensive transmission electron microscopy investigation was made to characterize the microstructures of the lath martensite in a low carbon steel of 0.2 wt%C. It was found that lots of lath martensites consist of twin as their substructure, rather than high density dislocations. In addition, nanoscale precipitates cohering with ferrite matrix were found at the twin interfaces. The orientation relationships between the precipitates and the ferrite matrix are in good agreement with that of primitive hexagonalωphase in titanium alloys and other bcc metals or alloys.&2016 Chinese Materials Research Society. Production and hosting by Elsevier B.V. This is an open access.

  17. Archaeologic analogues: Microstructural changes by natural ageing in carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Esther Bravo [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Fernandez, Jorge Chamon [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Arasanz, Javier Guzman [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Peces, Raquel Arevalo [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Criado, Antonio Javier [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Dietz, Christian [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Martinez, Juan Antonio [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Criado Portal, Antonio Jose [Dpto. de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)]. E-mail: antoniocriado@quim.ucm.es

    2006-02-15

    When discussing the container material for highly active radionuclear waste, carbon steel is one of the materials most frequently proposed by the international scientific community. Evidently, security with respect to the container behaviour into deep geological deposits is fundamental. Among other parameters, knowledge about material mechanical properties is essential when designing the container. Time ageing of carbon steel, apart from possible alterations of the chemical composition (e.g. corrosion) involves important microstructural changes, at the scale of centuries and millenniums. The latter may cause variations of the mechanical properties of carbon steel storage containers, with the corresponding risk of possible leakage. In order to properly estimate such risk and to adjust the corresponding mathematical models to reality, the microstructural changes observed in this study on archaeologic samples are evaluated, comparing ancient and modern steels of similar chemical composition and fabrication processes.

  18. Martensite Formation in Partially and Fully Austenitic Plain Carbon Steels

    NARCIS (Netherlands)

    Van Bohemen, S.M.C.; Sietsma, J.

    2009-01-01

    The progress of martensite formation in plain carbon steels Fe-0.46C, Fe-0.66C, and Fe-0.80C has been investigated by dilatometry. It is demonstrated that carbon enrichment of the remaining austenite due to intercritical annealing of Fe-0.46C and Fe-0.66C does not only depress the start temperature

  19. Analysis on the deformation and fracture behavior of carbon steel by in situ tensile test

    Institute of Scientific and Technical Information of China (English)

    Fan Li; Haibo Huang

    2006-01-01

    The deformation and fracture behaviors of low-carbon steel, medium-carbon steel, and high-carbon steel were studied on internal microstructure using the scanning electron microscopy in situ tensile test. The microstructure mechanism of their deformation and fracture behavior was analyzed. The results show that the deformation and fracture behavior of low-carbon steel depends on the grain size of ferrite, the deformation and fracture behavior of medium-carbon steel depends on the size of ferrite grain and pearlite lump,and the deformation and fracture behavior of high-carbon steel depends on the size of pearlite lump and the pearlitic interlamellar spacing.

  20. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Science.gov (United States)

    2010-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  1. Ultrafine-grained low carbon steels by severe plastic deformation

    Directory of Open Access Journals (Sweden)

    S. Dobatkin

    2008-07-01

    Full Text Available The structure and properties of 0,14% C and 0,1% C - B low-carbon steels taken in two initial states, martensitic and ferritic-pearlitic, were studied after cold equal-channel angular (ECA pressing. ECA pressing leads to the formation of only partially submicrocrystalline structure with a grain size of 150 – 300 nm, depending on the steel alloying and initial state. The finest structure with the elements of 190 nm in size is obtained in the 0,1% C - B steel microalloyed with boron. The strength of the 0,1% C - B steel after cold ECA pressing (Rm = 805-1235 MPa meets the specifications of fasteners of the R80 - R120 strength grade. The strength of the deformed 0,14% C steel is close to the R80 strength grade.

  2. In situ 3D monitoring of corrosion on carbon steel and ferritic stainless steel embedded in cement paste

    KAUST Repository

    Itty, Pierre-Adrien

    2014-06-01

    In a X-ray microcomputed tomography study, active corrosion was induced by galvanostatically corroding steel embedded in cement paste. The results give insight into corrosion product build up, crack formation, leaching of products into the cracks and voids, and differences in morphology of corrosion attack in the case of carbon steel or stainless steel reinforcement. Carbon steel was homogeneously etched away with a homogeneous layer of corrosion products forming at the steel/cement paste interface. For ferritic stainless steel, pits were forming, concentrating the corrosion products locally, which led to more extensive damage on the cement paste cover. © 2014 Elsevier Ltd.

  3. Ultrasonic inspection for circumferential butt joint of austenitic stainless steel with carbon steel

    Institute of Scientific and Technical Information of China (English)

    Wan Shengyun; Xiong Lasen

    2006-01-01

    Tthe practical application of ultrasonic wave inspection in welded joint by austenitic stainless steel with carbon steel is presented. It is shown from the experimental results that the high frequency narrow-pulsed longitudinal ultrasonic wave inspection technique can detect the defects in deferent sound path and location within the tested welded joint clearly and exactly. The study in the paper may provide a new approach for further application of ultrasonic inspection in coarse-grained materials.

  4. ESTIMATION OF IRREVERSIBLE DAMAGEABILITY AT FATIGUE OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2014-04-01

    Full Text Available Purpose. Damageability estimation of carbon steel in the conditions of cyclic loading. Methodology. The steel fragments of railway wheel rim and rail head served as material for research with chemical composition 0.65 % С, 0.67 % Mn, 0.3 % Si, 0.027 % P, 0.028 % S и 0.7 % C, 0.82 % Mn, 0.56 % Si, 0.025 % P, 0.029 % S accordingly. The microstructure of tested steels corresponded to the state of metal after a hot plastic deformation. The fatigue research was conducted in the conditions of symmetric bend using the proof-of-concept machine of type «Saturn-10». Full Wohler diagrams and the lines corresponding to forming of sub-and micro cracks were constructed. The distribution analysis of internal stresses in the metal under cyclic loading was carried out using the microhardness tester of PMT-3 type.Findings. On the basis of fatigue curves for high-carbon steels analysis the positions of borders dividing the areas of convertible and irreversible damages were determined. The article shows that with the growth of carbon concentration in the steel at invariability of the structural state an increase of fatigue limit is observed. At the same time the acceleration of processes, which determine transition terms from the stage of forming of submicrocracks to the microcracks occurs. The research of microhardness distribution in the metal after destruction confirmed the nature of carbon amount influence on the carbon steel characteristics. Originality. Regardless on the stages of breakdown site forming the carbon steels behavior at a fatigue is determined by the ration between the processes of strengthening and softening. At a cyclic loading the heterogeneity of internal stresses distribution decreases with the increase of distance from the destruction surface. Analysis of metal internal restructuring processes at fatigue loading made it possible to determine that at the stages prior to incubation period in the metal microvolumes the cells are already

  5. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    Abstract Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC...... of carbon steel must be monitored on-line in order to provide an efficient protection and control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic...... techniques even though localised corrosion rate cannot be measured. FSM measures general corrosion and detects localised corrosion, but the sensitivity is not high enough for monitoring initiation of pitting and small attacks. Electrochemical techniques as LPR and EIS give distorted data and unreliable...

  6. Austenite Recrystallization and Controlled Rolling of Low Carbon Steels

    Institute of Scientific and Technical Information of China (English)

    DU Lin-xiu; ZHANG Zhong-ping; SHE Guang-fu; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    The dynamic recrystallization and static recrystallization in a low carbon steel were investigated through single-pass and double-pass experiments. The results indicate that as the deformation temperature increases and the strain rate decreases, the shape of the stress-strain curve is changed from dynamic recovery shape to dynamic recrystallization shape. The austenite could not recrystallize within a few seconds after deformation at temperature below 900 ℃. According to the change in microstructure during deformation, the controlled rolling of low carbon steel can be divided into four stages: dynamic recrystallization, dynamic recovery, strain-induced ferrite transformation, and rolling in two-phase region. According to the microstructure after deformation, the controlled rolling of low carbon steel can be divided into five regions: non-recrystallized austenite, partly-recrystallized austenite, fully-recrystallized austenite, austenite to ferrite transformation, and dual phase.

  7. 78 FR 21105 - Circular Welded Carbon Steel Pipes and Tubes From Thailand: Preliminary Results of Antidumping...

    Science.gov (United States)

    2013-04-09

    ... Carbon Steel Pipes and Tubes from Thailand: 2011- 2012 Administrative Review,'' dated concurrently with... International Trade Administration Circular Welded Carbon Steel Pipes and Tubes From Thailand: Preliminary Results of Antidumping Duty Administrative Review; 2011- 2012 AGENCY: Import Administration,...

  8. Modeling Corrosion Reactions of Steel in a Dilute Carbonate Solution

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2016-02-01

    This research models the corrosion reactions of a high-strength steel in an aerated, dilute, carbonate solution during a single-cycle voltammetry. Based on a previous study (Eliyan et al. in J Mater Eng Perform 24(6):1-8, 2015) and a literature survey, the corrosion reactions of the cathodic reduction, anodic dissolution, and passivation, as well as the interfacial interactions and the chemistry of the corrosion products are illustrated in schematics. The paper provides a visual guide on the corrosion reactions for steel in carbonate solutions based on the available mechanistic details that were reported and are still being investigated in literature.

  9. Residual stress measurements in carbon steel

    Science.gov (United States)

    Heyman, J. S.; Min, N.

    1986-01-01

    External dc magnetic field-induced changes in natural velocity of Rayleigh surface waves were measured in steel specimens under various stress conditions. The low field slopes of curves representing the fractional changes of natural velocity were proved to provide correct stress information in steels with different metallurgical properties. The slopes of curves under uniaxial compression, exceeding about one third of the yield stress, fell below zero in all the specimens when magnetized along the stress axis. The slopes under tension varied among different steels but remained positive in any circumstances. The stress effect was observed for both applied and residual stress. A physical interpretation of these results is given based on the stress-induced domain structure changes and the delta epsilon effect. Most importantly, it is found that the influence of detailed metallurgical properties cause only secondary effects on the obtained stress information.

  10. Effect of hydrogen attack on acoustic emission behavior of low carbon steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to investigate the effect of hydrogen attack degree on acoustic emission (AE) behavior of low carbon steel during tensiling, specimens made of low carbon steel was exposed to hydrogen gas of 18 MPa at 450 and 500℃ for 240, 480 and 720 h respectively. Experimental results show that with increase of the hydrogen attack degree, the totally AE activity decreases during tensiling. In addition, the count of AE signals with high amplitude for the specimens with hydrogen attack keeps a constant which is less than that without hydrogen attack. It is concluded that AE signals originate in the specimens with hydrogen attack from intergranular fracture induced by methane blisterings or/and microcracks on grain boundaries.

  11. 77 FR 59892 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Affirmative Final Determination of...

    Science.gov (United States)

    2012-10-01

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Affirmative Final... mm to 5.0 mm. \\1\\ See Carbon and Certain Alloy Steel Wire Rod from Mexico: Affirmative Preliminary... on said entries.\\4\\ \\2\\ See Carbon and Certain Alloy Steel Wire Rod from Mexico: Initiation of...

  12. 78 FR 15376 - Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea

    Science.gov (United States)

    2013-03-11

    ... COMMISSION Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea On the basis... Korea and the antidumping duty orders on corrosion-resistant carbon steel flat products from Germany and... Corrosion-Resistant Carbon Steel Flat Products from Germany and Korea: Investigation Nos. 701-TA-350 and...

  13. Mechanical and corrosion behaviour of EUROFER 97 steel exposed to Pb-17Li

    Energy Technology Data Exchange (ETDEWEB)

    Benamati, G.; Fazio, C. E-mail: concetta@brasimone.enea.it; Ricapito, I

    2002-12-01

    Corrosion and tensile samples of the EUROFER 97 steel were exposed to Pb-17Li in the LIFUS II loop at 480 deg. C. The specimens were extracted after 1500, 3000 and 4500 h exposure. After extraction, weight change measurements and metallurgical analysis were performed on the corrosion specimens, while tensile tests were performed at 480 deg. C. The results showed that EUROFER 97 underwent uniform corrosion and the mechanical properties seem to be unaffected or only slightly affected by the liquid metal. In this paper, the results are reported and discussed also with reference to previous similar work.

  14. 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.

  15. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    and control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic techniques even though localised corrosion rate cannot be measured. FSM measures general......Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC of carbon steel must be monitored on-line in order to provide an efficient protection...... corrosion and detects localised corrosion, but the sensitivity is not high enough for monitoring initiation of pitting and small attacks. Electrochemical techniques as LPR and EIS give distorted data and unreliable corrosion rates, when biofilm and corrosion products cover the steel surface. However, EIS...

  16. Numerical simulation and experimental investigation of laser dissimilar welding of carbon steel and austenitic stainless steel

    Science.gov (United States)

    Nekouie Esfahani, M. R.; Coupland, J.; Marimuthu, S.

    2015-07-01

    This study reports an experimental and numerical investigation on controlling the microstructure and brittle phase formation during laser dissimilar welding of carbon steel to austenitic stainless steel. The significance of alloying composition and cooling rate were experimentally investigated. The investigation revealed that above a certain specific point energy the material within the melt pool is well mixed and the laser beam position can be used to control the mechanical properties of the joint. The heat-affected zone within the high-carbon steel has significantly higher hardness than the weld area, which severely undermines the weld quality. A sequentially coupled thermo-metallurgical model was developed to investigate various heat-treatment methodology and subsequently control the microstructure of the HAZ. Strategies to control the composition leading to dramatic changes in hardness, microstructure and service performance of the dissimilar laser welded fusion zone are discussed.

  17. Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel%Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    R Paventhan; P R Lakshminarayanan; V Balasubramanian

    2012-01-01

    Friction weIding is a solid state joining process used extensively currently owing to its advantages such as low heat input, high production efficiency, ease of manufacture, and environment friendliness. Materials difficult to be welded by fusion welding processes can be successfully welded by friction welding. An attempt was made to develop an empirical relationship to predict the tensile strength of friction welded AISI 1040 grade medium carbon steel and AISI 304 austenitic stainless steel, incorporating the process parameters such as friction pressure, forging pressure, friction time and forging time, which have great influence on strength of the joints. Response surface methodology was applied to optimize the friction welding process parameters to attain maximum tensile strength of the joint. The maximum tensile strength of 543 MPa could be obtained for the joints fabricated under the welding conditions of friction pressure of 90 MPa, forging pressure of 90 MPa, friction time of 6 s and forging time of 6 s.

  18. Carbon distribution in bainitic steel subjected to deformation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu. F., E-mail: yufi55@mail.ru [Institute of High Current Electronics SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Nikitina, E. N., E-mail: Nikitina-EN@mail.ru; Gromov, V. E., E-mail: gromov@physics.sibsiu.ru [Siberian State Industrial University, Novokuznetsk, 654007 (Russian Federation)

    2015-10-27

    Analysis of the formation and evolution of carbide phase in medium carbon steel with a bainitic structure during compressive deformation was performed by means of transmission electron diffraction microscopy. Qualitative transformations in carbide phase medium size particles, their density and volume concentration depended on the degree of deformation.

  19. Vanadium Effect on a Medium Carbon Forging Steel

    Directory of Open Access Journals (Sweden)

    Carlos Garcia-Mateo

    2016-05-01

    Full Text Available In the present work the influence of vanadium on the hardenability and the bainitic transformation of a medium carbon steel is analyzed. While V in solid solution enhances the former, it hardly affects bainitic transformation. The results also reveal an unexpected result, an increase of the prior austenite grain size as the V content increases.

  20. Erosion Effect of Molten Steel on Carbon Containing Refractories for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    LI Hongxia; YANG Bin; LIU Guoqi; CHENG Hepeng

    2007-01-01

    The erosion resistance of carbon containing refractories for continuous casting to molten steel was investigated by means of simulative erosion test and examining used refractories.Decolonization and reaction between molten steel and decolonization layer are main erosion process of carbon containing refractories by1 molten steel.The reactions between molten steel and oxide in refractories determine the thickness of decarbonization layer A dense layer formation on the working surface contacting with molten steel during casting will suppress decarbonization and erosion process.

  1. Corrosion behaviour of steels and refractory metals and tensile features of steels exposed to flowing PbBi in the LECOR loop

    Energy Technology Data Exchange (ETDEWEB)

    Fazio, C. E-mail: concetta.fazio@psf.fzk.de; Ricapito, I.; Scaddozzo, G.; Benamati, G

    2003-05-15

    An experimental activity has been started using the LECOR loop at the ENEA Brasimone centre to investigate the corrosion behaviour of steels and refractory metals as well as the tensile properties of steels exposed to flowing liquid lead bismuth with low oxygen activity. The oxygen content in the liquid metal was controlled and monitored by a dedicated system. The compatibility test was performed at 673 K and the corrosion and tensile results herein reported concern the first 1500-h run of the loop operation. All the materials tested suffered from liquid metal attack exhibiting a weight loss. The consequent evaluation of the corrosion rate showed that, under the given test conditions, the refractory metals are more resistant than the steels. The tensile properties of austenitic steel are not affected by the liquid metal corrosion, while the martensitic steel exhibited a mixed brittle-ductile fracture surface.

  2. Elastic Sag Property of Low Carbon Martensite Spring Steel

    Institute of Scientific and Technical Information of China (English)

    LI Ye-sheng; CHEN Mi-song; WU Zi-ping; ZHU Yin-lu; DUO Tie-yun

    2004-01-01

    This paper studies the elastic sag resistance of new low-carbon martensite spring steel 35Si2CrVB developed recently and points out that the cause of elastic sag is attributed to cyclic softening of spring steel engendered during its serving,also considers that elastic sag property should be evaluated by dynamic mechanical properties of spring material such as dynamic yield strength σ'0.2, ratio of dynamic yield strength σ'0.2 vs. tensile strength σb (σ'0.2/σb) and ratio of dynamic yield strength σ' 0.2vs. static yield strengthσ0.2 (σ'0.2/σ0. 2 )etc. , which are measured by the cyclic stress-strain curve test. Compared with conventional spring steel 60Si2MnA, 35Si2CrVB has good advantages in both dynamic and static properties, which show it possesses higher elastic sag resistance than 60Si2MnA because of its lath-martensite structure tempering in low temperature different from 60Si2MnA steel's plate martensite structure tempering inmedium temperature. So it can be demonstrated that low carbon martensite spring steel is more appropriate for the demands of spring.

  3. Weldability of Low Carbon Transformation Induced Plasticity Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Mei; LI Lin; FU Ren-yu; ZHANG Ji-cheng; WAN Zi

    2008-01-01

    Transformation induced plasticity (TRIP) steel exhibited high or rather high carbon equivalent (CE) because of its chemical composition,which was a particularly detrimental factor affecting weldability of steels.Thus the weldability of a TRIP steel (grade 600) containing (in mass percent,%) 0.11C-1.19Si-1.67Mn was extensively studied.The mechanical properties and impact toughness of butt joint,the welding crack susceptibility of weld and heat affected zone (HAZ) for tee joint,control thermal severity (CTS) of the welded joint,and Y shape 60° butt joint were measured after the gas metal arc welding (GMAW) test.The tensile strength of the weld was higher than 700 Mpa.Both in the fusion zone (FZ) and HAZ for butt joint,the impact toughness was much higher than 27 J,either at room temperature or at -20 ℃,indicating good low temperature impact ductility of the weld of TRIP 600 steel.In addition,welding crack susceptibility tests revealed that weldments were free of surface crack and other imperfection.All experimental results of this steel showed fairly good weldability.For application,the crossmember in automobile made of this steel exhibited excellent weldability,and fatigue and durability tests were also accomplished for crossmember assembly.

  4. Morphological and microstructural studies on aluminizing coating of carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Samsu, Zaifol; Othman, Norinsan Kamil; Daud, Abd Razak; Hussein, Hishammuddin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2013-11-27

    Hot dip aluminizing is one of the most effective methods of surface protection for steels and is gradually gaining popularity. The morphology and microstructure of an inter-metallic layer form on the surface of low carbon steel by hot dip aluminization treatment had been studied in detail. This effect has been investigated using optical and scanning electron microscopy, and X-ray diffraction. The result shows that the reaction between the steel and the molten aluminium leads to the formation of Fe–Al inter-metallic compounds on the steel surface. X-ray diffraction and electron microscopic studies showed that a two layer coating was formed consisting of an external Al layer and a (Fe{sub 2}Al{sub 5}) inter metallic on top of the substrate after hot dip aluminizing process. The inter-metallic layer is ‘thick’ and exhibits a finger-like growth into the steel. Microhardness testing shown that the intermetallic layer has high hardness followed by steel substrate and the lowest hardness was Al layer.

  5. Novel sintered ceramic materials incorporated with EAF carbon steel slag

    Science.gov (United States)

    Karayannis, V.; Ntampegliotis, K.; Lamprakopoulos, S.; Papapolymerou, G.; Spiliotis, X.

    2017-01-01

    In the present research, novel sintered clay-based ceramic materials containing electric arc furnace carbon steel slag (EAFC) as a useful admixture were developed and characterized. The environmentally safe management of steel industry waste by-products and their valorization as secondary resources into value-added materials towards circular economy have attracted much attention in the last years. EAF Carbon steel slag in particular, is generated during the manufacture of carbon steel. It is a solid residue mainly composed of rich-in- Fe, Ca and Si compounds. The experimental results show that the beneficial incorporation of lower percentages of EAFC up to 6%wt. into ceramics sintered at 950 °C is attained without significant variations in sintering behavior and physico-mechanical properties. Further heating up to 1100 °C strongly enhances the densification of the ceramic microstructures, thus reducing the porosity and strengthening their mechanical performance. On the other side, in terms of thermal insulation behavior as well as energy consumption savings and production cost alleviation, the optimum sintering temperature appears to be 950 °C.

  6. 76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...

    Science.gov (United States)

    2011-03-21

    ..., fully stabilized (commonly referred to as interstitial-free (IF)) steels, high strength low alloy (HSLA...), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels with...; high strength low alloy; and the substrate for motor lamination steel may also enter under...

  7. THE MACHINING OF HARDENED CARBON STEELS BY COATED CUTTING TOOLS

    Directory of Open Access Journals (Sweden)

    Yusuf ŞAHİN

    2001-02-01

    Full Text Available The investigation of machining AISI 1050 carbon steels hardened to the 60 HRC hardness was carried out to determine the tool life and wear behaviour of the various cutting tools under different conditions. These experiments were conducted at using coated ceramic cutting tools and carbide cutting tools. The experimental results showed that the coated ceramic tools exhibited better performance than those of the coated carbide tools when machining the hardened steels. Moreover, wear behaviour of cutting tools were investigated in a scanning electron microscope. Electron microscopic examination also indicated that flank wear, thermal cracks on the tool nose combined with the nose deformation on the tools were responsible for the wear behaviour of the ceramic tools. For the carbide tools, however, removal of coated material from the substrate tool and combined with the crater wear were effective for the machining the hardened steel.

  8. Effects of tempering on internal friction of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Hoyos, J.J., E-mail: jjhoyos@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia); Ghilarducci, A.A., E-mail: friccion@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Instituto Balseiro-Universidad Nacional de Cuyo, Consejo Nacional de Investigaciones Cientificas y Tecnologicas, Av. Bustillo 9500, 8400 Bariloche RN (Argentina); Salva, H.R., E-mail: salva@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Instituto Balseiro-Universidad Nacional de Cuyo, Consejo Nacional de Investigaciones Cientificas y Tecnologicas, Av. Bustillo 9500, 8400 Bariloche RN (Argentina); Chaves, C.A., E-mail: cachaves@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia); Velez, J.M., E-mail: jmvelez@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia)

    2011-04-15

    Research highlights: {yields} Time tempering dependent microstructure of two steels is studied by internal friction. {yields} Internal friction indicates the interactions of dislocations with carbon and carbides. {yields} Internal friction detects the first stage of tempering. {yields} Precipitation hardening is detected by the decrease in the background. - Abstract: Two steels containing 0.626 and 0.71 wt.% carbon have been studied to determine the effects of tempering on the microstructure and the internal friction. The steels were annealed at 1093 K, quenched into water and tempered for 60 min at 423 K, 573 K and 723 K. The increase of the tempering time diminishes the martensite tetragonality due to the redistribution of carbon atoms from octahedrical interstitial sites to dislocations. Internal friction spectrum is decomposed into five peaks and an exponential background, which are attributed to the carbide precipitation and the dislocation relaxation process. Simultaneous presence of peaks P1 and P2 indicates the interaction of dislocations with the segregated carbon and carbide precipitate.

  9. 77 FR 54926 - Certain Seamless Carbon and Alloy Steel; Standard, Line, and Pressure Pipe From Germany

    Science.gov (United States)

    2012-09-06

    ... COMMISSION Certain Seamless Carbon and Alloy Steel; Standard, Line, and Pressure Pipe From Germany... steel standard, line, and pressure pipe from Germany would be likely to lead to continuation or... 2012), entitled Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from...

  10. Heat exchange performance of stainless steel and carbon foams modified with carbon nano fibers

    NARCIS (Netherlands)

    Tuzovskaya, I.; Pacheco Benito, S.; Chinthaginjala, J.K.; Reed, C.P.; Lefferts, L.; Meer, van der T.H.

    2012-01-01

    Carbon nanofibers (CNF), with fishbone and parallel wall structures, were grown by catalytic chemical vapor deposition on the surface of carbon foam and stainless steel foam, in order to improve their heat exchange performance. Enhancement in heat transfer efficiency between 30% and 75% was achieved

  11. Electrochemical corrosion behavior of carbon steel with bulk coating holidays

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS (Electrochemical Impedance Spectroscopy) in a 3.5vol% NaCl aqueous solution.The area ratio of bulk coating holiday to total coating area of steel is 4.91%. The experimental results showed that at free corrosionpotential, the corrosion of carbon steel with disbonded coating holiday is heavier than that with broken holiday and disbonded & broken holiday with time; Moreover, the effectiveness of Cathodic Protection (CP) of carbon steel with broken holiday is better than that with disbonded holiday and disbonded & broken holiday on CP potential -850 mV (vs CSE). Further analysis indicated that the two main reasons for corrosion are electrolyte solution slowly penetrating the coating, and crevice corrosion at steel/coating interface near holidays. The ratio of impedance amplitude (Z) of different frequency to minimum frequency is defined as K value. The change rate of K with frequency is related to the type of coating holiday.

  12. The Study on 400 MPa Class Plain Carbon Structure Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; LI Sheng-li; LI Wei-juan; DU Lin-xiu; WANG Guo-dong

    2004-01-01

    New generation of structure steel has been developed to meet the uninterruptedly increasing needs of the economic construction and development of society, and such material is characterized by ultra-fine grain. In this paper, 400MPa class plain carbon structure steel has been studied, making its yield strength doubled and service life doubled on the basis of good comprehensive properties in large quantity utilization. The deformation behavior and the stain induced transformation of SS400 steel at different temperature were investigated in the laboratory, and the industrial rolling test was carried out in 2 050mm HSM of Baosteel. Not only the laboratory studies but also the industrial test show that the technical route of the experimentis correct and the industrial test results on the basis of low carbon plain steel indicate that the grain size of ferrite was near to 4 ~ 5 μm, elongation was more than 30% , impact property was good, the yield strength can reach 400 MPa.

  13. A new nanoscale metastable iron phase in carbon steels

    Science.gov (United States)

    Liu, Tianwei; Zhang, Danxia; Liu, Qing; Zheng, Yanjun; Su, Yanjing; Zhao, Xinqing; Yin, Jiang; Song, Minghui; Ping, Dehai

    2015-01-01

    Metastable ω phase is common in body-centred cubic (bcc) metals and alloys, including high-alloying steels. Recent theoretical calculations also suggest that the ω structure may act as an intermediate phase for face-centred cubic (fcc)-to-bcc transformation. Thus far, the role of the ω phase played in fcc-bcc martensitic transformation in carbon steels has not been reported. In previous investigations on martensitic carbon steels, extra electron diffraction spots were frequently observed by transmission electron microscopy (TEM), and these spots were historically ascribed to the diffraction arising from either internal twins or carbides. In this paper, an intensive TEM investigation revealed that the extra spots are in fact attributed to the metastable ω phase in particle-like morphology with an overall size of several or dozens of nanometres. The strict orientation relationships between the ω phase and the ferrite matrix are in good agreement with those of the hexagonal (P6/mmm) ω phase in other bcc metals and alloys. The identification of the ω phase as well as the extra diffraction spots might provide a clue to help understand the physical mechanism of martensitic transformation in steels. PMID:26503890

  14. Behavior of portal frames of steel hollow sections exposed to fire

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmoud El-Heweity

    2012-06-01

    Full Text Available This paper presents a numerical study concerning the behavior of hollow sections steel portal frames exposed to fire. A model is developed to employ both thermal and structural responses incorporating material and geometric non-linearities. To establish the failure mechanism of a frame under fire conditions, a failure criterion is proposed and validated against available experimental data. The failure temperatures predicted through the suggested failure criterion show good agreement compared to the experimental results. A parametric study is then conducted using the calibrated model to focus on failure mechanisms and associated failure temperatures. Variables considered are fire condition and rafter’s inclination angle. The assessment of frame performance is based on the generated failure mechanism and enhancement of failure temperature due to the chosen parameters. Results indicate that the studied variables strongly affect the failure mechanisms of portal frames. Contradictory, their effects on the failure temperature are minimal. Finally, the study presents vital outlines for the designer to find out and hence trace the failure mechanism prior to the completion of the final design stage. Only at this point, the optimum fire protection or adequate section capacity can be accomplished and may seriously be implemented in the field of industrial steel constructions.

  15. 76 FR 45509 - Final Results of Antidumping Duty Changed Circumstances Review: Carbon and Certain Alloy Steel...

    Science.gov (United States)

    2011-07-29

    ... Circumstances Review: Carbon and Certain Alloy Steel Wire Rod from Mexico, 75 FR 67685 (November 3, 2010...: Carbon and Certain Alloy Steel Wire Rod From Mexico, 71 FR 27989 (May 15, 2006). Notification This notice... International Trade Administration Final Results of Antidumping Duty Changed Circumstances Review: Carbon...

  16. Inhibition Performance of Enhanced-Mo Inhibitor for Carbon Steel in 55% LiBr Solution

    Institute of Scientific and Technical Information of China (English)

    LIANG Cheng-hao; HU Xian-qi

    2008-01-01

    The inhibition performance of enhanced-Mo inhibitor for carbon steel in 55% LiBr solution was measured by means of chemical immersion, electrochemical measurements, and physical detection technologies. Results indicated that enhanced-Mo inhibitor showed excellent inhibition performance of carbon steel in 55% LiBr solution, especially at high temperature. With increasing the temperature of solution from 160 ℃ to 240 ℃, the corrosion rates of carbon steel increased from 17.67 μm/a to 33.07 μm/a. Enhanced-Mo inhibitor might improve the anodic polarization performance of carbon steel and widen the passive potential region of carbon steel in 55% LiBr solution. Enhanced-Mo inhibitor belongs to anodic inhibitor. In 55% LiBr solution, the relationship between corrosion current density icorr and corrosion potential Ecorr of carbon steel accorded with the equation lgicorr=-2.66-3.54Ecorr, and the value of cathodic Tafel constant βc for the H2 reaction was 282 mVSCE. When 55% LiBr solution contained enhanced-Mo inhibitor, a passive film comprising Fe3O4 and MoO2 was formed on the carbon steel surface by electrochemical reactions. The corrosion of carbon steel might be retarded by this protective film, and the anticorrosion performance of carbon steel in 55% LiBr solution might be improved by enhanced-Mo inhibitor.

  17. Deformation Behavior of Ultra-low Carbon Steel in Ferrite Region during Warm Processing

    Institute of Scientific and Technical Information of China (English)

    XU Guang; CHEN Zhenye; LIU Li; YU Shengfu

    2008-01-01

    The hot deformation experiments of ultra-low carbon steel in ferrite range were carried out ina hot simulator in order to research hot deformation behaviors of ultra-low carbon steel in ferrite range at low temperature.The results show that the influences of deformation parameters on flow stress are different to those in austenitic deformation.The deformation characteristic parameters were calculated for ultra-low carbon steel in ferrite region.The flow stress equation for ultra-low carbon steel in ferritic deformation at low temperature was obtained.

  18. Research on Welding Test of Grey Cast Iron and Low-Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Grey cast iron's welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks ...

  19. Effect of Carbon Steel Composition and Microstructure on CO2 Corrosion

    Science.gov (United States)

    Akeer, Emad S.

    The environmental conditions encountered in oil and gas wells and pipelines can cause severe localized corrosion to mild steel. The utility of carbon steel in oil and gas pipelines depends on formation of protective corrosion product layers. However, the microstructure and chemical composition of steel are considered to be important variables that affect the ability of these layers to protect steel from corrosion. The present study investigated the effect of alloying elements and metallurgy of five different pipeline steels, with different chemical composition and microstructure, on CO2 corrosion in flowing conditions with focus on the iron carbonate layer formed and related corrosion phenomena that could lead to localized corrosion. The microstructure of tested steels was examined using optical microscopy and etching. Preliminary experiments were conducted using a glass cell, which is a very well known and widely used apparatus. Then a comparison was done with the newly developed thin channel flow cell (TCFC) to validate whether the TCFC can be used instead of glass cell in this study, which required very high velocity and wall shear stresses. It was found that there are no significant effects of alloying elements and steel microstructure on corrosion rate in experiments done at pH 4.0 at 25°C and 80°C. Further experiments were then conducted in the TCFC to study the effect of alloying elements and microstructure under conditions where a protective FeCO3 4 corrosion product layer forms, using very high liquid flow rates. For each of the studied steels, an FeCO3 corrosion product layer was formed within two days of exposure at low wall shear stress at 80°C, pH 6.6, and partial pressure of CO2 of 1.5 bar (1.5 bar pCO 2). For all tested steels, the FeCO3 layer reduced the general corrosion rate to less than 1.0 mm/y. These "pre-formed" FeCO3 layers were then exposed to high liquid flow velocity and wall shear stress (535 Pa) for 3 days. This caused partial loss of

  20. INFLUENCE OF ELECTRIC SPARK ON HARDNESS OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2014-03-01

    Full Text Available Purpose. The purpose of work is an estimation of influence of an electric spark treatment on the state of mouldable superficial coverage of carbon steel. Methodology. The steel of fragment of railway wheel rim served as material for research with chemical composition 0.65% С, 0.67% Mn, 0.3% Si, 0.027% P, 0.028% S. Structural researches were conducted with the use of light microscopy and methods of quantitative metallography. The structural state of the probed steel corresponded to the state after hot plastic deformation. The analysis of hardness distribution in the micro volumes of cathode metal was carried out with the use of microhardness tester of type of PMT-3. An electric spark treatment of carbon steel surface was executed with the use of equipment type of EFI-25M. Findings. After electric spark treatment of specimen surface from carbon steel the forming of multi-layered coverage was observed. The analysis of microstructure found out the existence of high-quality distinctions in the internal structure of coverage metal, depending on the probed area. The results obtained in the process are confirmed by the well-known theses, that forming of superficial coverage according to technology of electric spark is determined by the terms of transfer and crystallization of metal. The gradient of structures on the coverage thickness largely depends on development of structural transformation processes similar to the thermal character influence. Originality. As a result of electric spark treatment on the condition of identical metal of anode and cathode, the first formed layer of coverage corresponds to the monophase state according to external signs. In the volume of coverage metal, the appearance of carbide phase particles is accompanied by the decrease of microhardness values. Practical value. Forming of multi-layered superficial coverage during electric spark treatment is accompanied by the origin of structure gradient on a thickness. The effect

  1. A Spray Pyrolysis Method to Grow Carbon Nanotubes on Carbon Fibres, Steel and Ceramic Bricks.

    Science.gov (United States)

    Vilatela, Juan J; Rabanal, M E; Cervantes-Sodi, Felipe; García-Ruiz, Máximo; Jiménez-Rodríguez, José A; Reiband, Gerd; Terrones, Mauricio

    2015-04-01

    We demonstrate a spray pyrolysis method to grow carbon nanotubes (CNTs) with high degree of crystallinity, aspect ratio and degree of alignment on a variety of different substrates, such as conventional steel, carbon fibres (CF) and ceramics. The process consists in the chemical vapour deposition of both a thin SiO2 layer and CNTs that subsequently grow on this thin layer. After CNT growth, increases in specific surface by factors of 1000 and 30 for the steel and CF samples, respectively, are observed. CNTs growth on ceramic surfaces results in a surface resistance of 37.5 Ohm/sq. When using conventional steel as a rector tube, we observed CNTs growth rates of 0.6 g/min. Details of nanotube morphology and the growth mechanism are discussed. Since the method discussed here is highly versatile, it opens up a wide variety of applications in which specific substrates could be used in combination with CNTs.

  2. Mechanical Properties and Corrosion Behavior of Low Carbon Steel Weldments

    Directory of Open Access Journals (Sweden)

    Mohamed Mahdy

    2013-01-01

    Full Text Available This research involves studying the mechanical properties and corrosion behavior of “low carbon steel” (0.077wt% C before and after welding using Arc, MIG and TIG welding. The mechanical properties include testing of microhardness, tensile strength, the results indicate that microhardness of TIG, MIG welding is more than arc welding, while tensile strength in arc welding more than TIG and MIG.The corrosion behavior of low carbon weldments was performed by potentiostat at scan rate 3mV.sec-1 in 3.5% NaCl to show the polarization resistance and calculate the corrosion rate from data of linear polarization by “Tafel extrapolation method”. The results indicate that the TIG welding increase the corrosion current density and anodic Tafel slop, while decrease the polarization resistance compared with unwelded low carbon steel. Cyclic polarization were measured to show resistance of specimens to pitting corrosion and to calculate the forward and reveres potentials. The results show shifting the forward, reverse and pitting potentials toward active direction for weldments samples compared with unwelded sample.

  3. Austenite and ferrite grain size evolution in plain carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Militzer, M.; Giumelli, A.; Hawbolt, E.B.; Meadowcroft, T.R. [British Columbia Univ., Vancouver, BC (Canada)

    1995-01-01

    Grain size evolution in a 0.17%C, 0.74%Mn plain carbon steel is investigated using a Gleeble 1500 thermomechanical simulator. Austenite grain growth measurements in the temperature range from 900 to 1150{degrees}C have been used to validate the Abbruzzese and Luecke model, which is recommended for simulating grain growth during reheating. For run-out table conditions, the ferrite grain size decreases from 1l{mu}m to 4{mu}m when the cooling rate from the austenite is increased from 1 to 80{degrees}C/s.

  4. Hybrid Friction Stir Welding of High-carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Don-Hyun Choi; Seung-Boo Jung; Chang-Yong Lee; Byung-Wook Ahn; Jung-Hyun Choi; Yun-Mo Yeon; Keun Song; Seung-Gab Hong; Won-Bae Lee; Ki-Bong Kang

    2011-01-01

    A high-carbon steel joint, SK5 (0.84 wt% C), was successfully welded by friction stir welding (FSW), both without and with a gas torch, in order to control the cooling rate during welding. After welding, the weld zone comprised gray and black regions, corresponding to microstructural variation: a martensite structure and a duplex structure of ferrite and cementite, respectively. The volume fraction of the martensite structure and the Vickers hardness in the welds were decreased with the using of the gas torch, which was related with the lower cooling rate.

  5. Corrosion inhibition of carbon steel by extract of Buddleia perfoliata

    Directory of Open Access Journals (Sweden)

    ROY LOPES-SESENES

    2012-06-01

    Full Text Available Buddleia perfoliata leaves extract has been investigated as a carbon steel corrosion inhibitor in 0.5 M sulfuric acid by using polarization curves, electrochemical impedance spectroscopy and weight-loss tests at different concentrations (0, 100, 200, 300, 400 and 500 ppm and temperatures, namely 25, 40 and 60 °C. Results showthat inhibition efficiency increases as the inhibitor concentration increases, decreases with temperature, and reaches a maximum value after 12 h of exposure, decreasing with a further increase in the exposure time. It was found that the inhibitory effect is due to the presence of tannines on this extract.

  6. Corrosion Inhibition of Carbon Steel in Chloride and Sulfate Solutions

    Directory of Open Access Journals (Sweden)

    Amr Ahmed Elsayed

    2016-02-01

    Full Text Available Corrosion is a major problem in industry and in infrastructure; a huge sum of expenditure every year is spent on preventing, retarding, and repairing its damages. This work studies the engineering of an inhibitor for carbon steel metal used in the cooling systems containing high concentration of chloride and sulfate ions. For this purpose, the synergy between the dichromate, molybdate and nitrite inhibitors is examined and optimized to the best results. Moreover, care was taken that the proposed inhibitor is compliant with the environmental laws and regulations.

  7. Recrystallization of High Carbon Steel during High Strain Rate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The recrystallization of high carbon steel during high temperature and high speed rolling has been studied by analyzing the stress-strain curves and the austenite grain size.Isothermal multi-pass hot compression at high strain rate was carried out by Gleeble-2000. The austenite grain size was measured by IBAS image analysis system. The results show that static recrystallization occurred at interpass time under pre-finish rolling, and at the finish rolling stage, due to the brief interpass time, static recrystallization can not be found.

  8. Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

    Science.gov (United States)

    Eliezer, D.; Nelson, H. G.

    1978-01-01

    An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

  9. 78 FR 16252 - Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, and Thailand: Final Results...

    Science.gov (United States)

    2013-03-14

    ... interstitial-free (``IF'')) steels, high strength low alloy (``HSLA'') steels, and the substrate for motor... and nitrogen elements. HSLA steels are recognized as steels with micro-alloying levels of elements... International Trade Administration Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia,...

  10. 75 FR 43931 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Preliminary Results of...

    Science.gov (United States)

    2010-07-27

    ... (``IF'')) steels, high strength low alloy (``HSLA'') steels, and the substrate for motor lamination... titanium and/or niobium added to stabilize carbon and nitrogen elements. HSLA steels are recognized as... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from...

  11. 76 FR 22868 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of...

    Science.gov (United States)

    2011-04-25

    ... (``IF'')) steels, high strength low alloy (``HSLA'') steels, and the substrate for motor lamination... titanium and/or niobium added to stabilize carbon and nitrogen elements. HSLA steels are recognized as... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From...

  12. Efficiency of inhibitor for biocorrosion influenced by consortium sulfate reducing bacteria on carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Mahat, Nur Akma; Othman, Norinsan Kamil [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Sahrani, Fathul Karim [School of Environment and Natural Resources Science, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    The inhibition efficiency of benzalkonium chloride (BKC) in controlling biocorrosion on the carbon steel surfaces has been investigated. The carbon steel coupons were incubated in the presence of consortium SRB (C-SRB) with and without BKC for the difference medium concentration. The corrosion rate and inhibition efficiency have been evaluated by a weight loss method. The morphology of biofilm C-SRB on the steel surfaces were characterized with variable pressure scanning electron microscopy (VPSEM). The results revealed that BKC exhibits a low corrosion rate, minimizing the cell growth and biofilm development on the carbon steel surfaces.

  13. Efficiency of inhibitor for biocorrosion influenced by consortium sulfate reducing bacteria on carbon steel

    Science.gov (United States)

    Mahat, Nur Akma; Othman, Norinsan Kamil; Sahrani, Fathul Karim

    2015-09-01

    The inhibition efficiency of benzalkonium chloride (BKC) in controlling biocorrosion on the carbon steel surfaces has been investigated. The carbon steel coupons were incubated in the presence of consortium SRB (C-SRB) with and without BKC for the difference medium concentration. The corrosion rate and inhibition efficiency have been evaluated by a weight loss method. The morphology of biofilm C-SRB on the steel surfaces were characterized with variable pressure scanning electron microscopy (VPSEM). The results revealed that BKC exhibits a low corrosion rate, minimizing the cell growth and biofilm development on the carbon steel surfaces.

  14. Distribution of radionuclides during melting of carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Thurber, W.C.; MacKinney, J.

    1997-02-01

    During the melting of steel with radioactive contamination, radionuclides may be distributed among the metal product, the home scrap, the slag, the furnace lining and the off-gas collection system. In addition, some radionuclides will pass through the furnace system and vent to the atmosphere. To estimate radiological impacts of recycling radioactive scrap steel, it is essential to understand how radionuclides are distributed within the furnace system. For example, an isotope of a gaseous element (e.g., radon) will exhaust directly from the furnace system into the atmosphere while a relatively non-volatile element (e.g., manganese) can be distributed among all the other possible media. This distribution of radioactive contaminants is a complex process that can be influenced by numerous chemical and physical factors, including composition of the steel bath, chemistry of the slag, vapor pressure of the particular element of interest, solubility of the element in molten iron, density of the oxide(s), steel melting temperature and melting practice (e.g., furnace type and size, melting time, method of carbon adjustment and method of alloy additions). This paper discusses the distribution of various elements with particular reference to electric arc furnace steelmaking. The first two sections consider the calculation of partition ratios for elements between metal and slag based on thermodynamic considerations. The third section presents laboratory and production measurements of the distribution of various elements among slag, metal, and the off-gas collection system; and the final section provides recommendations for the assumed distribution of each element of interest.

  15. Microstructure and Property of High Carbonic-Chromium Cast Steel with Different Hot Deformation Ratio

    Institute of Scientific and Technical Information of China (English)

    XU Tao; WANG Jiu-liang; ZHANG Run-jun; CHAO Guo-hua; LIU Jian-hua

    2004-01-01

    The microstructure and properties of high carbonic-chromium cast steel subjected to different hot deformation ratios were studied. The experimental results show that the microstructure and properties of high carbonic-chromium cast steel are obviously improved after hot deformation, and the best mechanical properties of the cast steel can be obtained under hot deformation ratio of 40 %-50 %, which leads to the morphology change of eutectic carbide and the precipitation of granular carbides.

  16. A study on the impediment of thickness diminution of carbon steel tube using applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Oh; Hong, Seong Min [Chungnam National Univ., Taejon (Korea, Republic of); Park, Yun Won [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    2002-03-15

    Carbon steel pipe is used as a pipe laying for the cooling water of nuclear reactor. In order to examine the diminution of steel thickness, the magnetic field permeability of applicable permanent magnets was simulated by computer. The susceptibility of the permanent magnets according to the temperature was measured to investigate the applicability of permanent magnets at the cooling water temperature of nuclear power plant. The structure and magnetic properties of carbon steel tube were observed regarding to the existence of oxidized layer.

  17. 76 FR 78882 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Affirmative Preliminary Determination of...

    Science.gov (United States)

    2011-12-20

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Affirmative Preliminary... Administration, Department of Commerce. SUMMARY: We preliminarily determine that carbon and certain alloy steel wire rod (wire rod) with an actual diameter between 4.75 mm and 5.00 mm produced in Mexico and...

  18. 78 FR 2658 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Rescission of Antidumping Duty...

    Science.gov (United States)

    2013-01-14

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Rescission of... its administrative review of the antidumping duty order on carbon and certain alloy steel wire rod (``wire rod'') from Mexico for the period October 1, 2011, through September 30, 2012. DATES:...

  19. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  20. Laser alloying of the plain carbon steel surface layer

    Directory of Open Access Journals (Sweden)

    A. Radziszewska

    2008-07-01

    Full Text Available As an example of the types of features observed after laser alloying, the addition of Ta to mild carbon steel is described. The system is of interest because such alloying is beneficial in improving surface related properties. The paper describes the microstructure and properties (phase and chemical composition, microhardness of the laser alloyed surface layer. In the investigation the optical microscope, the scanning electron microscope (SEM, chemical (EDS microanalysis composition and microhardness testing methods have been used. Specimens of 0,17 %C plain steel were coated with Ta powder layers. The paints containing organic components were used as the binders during deposition of Ta powder layers on the sample surface. The thickness of Ta deposited layers amounted to 0,16 mm. The specimens were then swept through high power (of nominal power 2,5 kW CW CO2 laser radiation at different speeds.The surface alloyed layers varied in microstructure consisted of fiber like Ta2C + γ eutectics, chemical composition and microhardness. The EDS analyses revealed the enrichment of tantalum in the laser alloyed zone (LAZ. The changes of process parameters had an influence on the hardness of alloyed surface layers: by increasing scanning velocity (from 12 mm/s to 20 mm/s and decreasing laser power (from 1,8 kW to 1,35 kW, the hardness diminished. The wear tests were also carried out which showed that laser alloying of plain carbon steel surface layer led to improvement of their wear resistance.

  1. Reduction of work hardening rate in low-carbon steels

    Science.gov (United States)

    Yalamanchili, Bhaskar Rao

    Low carbon grades of steel rods are used to produce finished products such as fine wire, coat hangers, staples, and roofing nails. These products are subject to ductility failures during production due to excessively high work hardening rates during wire drawing. The high work hardening rates are attributed to the presence of residuals, free nitrogen, or combinations thereof. This research concludes that the most cost-effective way to reduce the work hardening rate during wire drawing is to combine boron with nitrogen to form boron nitride, and thus reducing its work hardening contribution. The results of this study also conclude the following: (1) Boron/Nitrogen ratio is the more significant factor than rod tensile strength, which affects work hardening rate. Higher ratio is better in the 0.79 to 1.19 range. (2) Maintaining this narrow B/N range requires precise process control. (3) Process conditions such as dissolved oxygen (Steel Texas (North Star) benefited from this research by being able to provide a competitive edge in both quality and cost of its low carbon boron grades thus making North Star a preferred supplier of wire rod for these products.

  2. CORROSION BEHAVIORS OF THE EXPOSED SIDE AND UNDERSIDE OF LOW ALLOY WEATHERING STEEL IN QINGDAO AND WANNING FOR 18 MONTHS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    For 18 months, a newly developed low alloy weathering steel has been exposed in two coastal sites (Qingdao in the north China, Wanning in the south China). The different corrosion behaviors of the exposed side and the underside of the samples were characterized by X-ray diffraction (XRD), polarization curve, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and N2 adsorp-tion approach. It was found that the samples exhibited higher corrosion rate in Wan-ning than that in Qingdao. The underside of the samples corrodes more seriously than the exposed side in Qingdao, whereas the result in Wanning is just the reverse.The protection performance of rust layers mainly depends on its compactness and the enrichment of Cu and Cr is a secondary causation. The different compactness of rust layers in the exposed side and the underside originates from different corrosion conditions of the two sides.

  3. Fireside corrosion and steamside oxidation of 9-12% Cr martensitic steels exposed for long term testing

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Jensen, S. A.; Rasmussen, F.

    2009-01-01

    To obtain long term corrosion and steam oxidation data for the 9-12%Cr ferritic steels, test tube sections have been exposed in Amager 3 and Avedore 1 coal fired power plants in Denmark (formerly run by ENERGI E2). Thus direct comparisons can be made for T91 and T92 for the 9% Cr steels and X20Cr......MoV121 and HCM12 for the 12% Cr steels. The test tubes were welded in as part of the existing final superheaters in actual plants and exposure has been conducted over a ten year period (1994-2005). Compared to the older steel types, T92 and HCM12 utilise tungsten to improve their creep strength. From...... Avedore I testing, T91 and T92 can be compared for exposure times up to similar to 48 000 h exposure. From Amager 3 testing, X20, HCM12 and T92 were tested; T92 has been exposed for up to 31 000 h and X20 and HCM12 have had 84 500 h exposure. Tube sections were removed for various exposure durations...

  4. 76 FR 16607 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Notice of Partial Rescission of Antidumping...

    Science.gov (United States)

    2011-03-24

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Notice of Partial... antidumping duty order on carbon and certain alloy steel wire rod from Mexico. See Antidumping or... carbon and certain alloy steel wire rod from Mexico, in part, with respect to DeAcero, Aceros,...

  5. 78 FR 28190 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Final Results of Antidumping Duty...

    Science.gov (United States)

    2013-05-14

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Final Results of... carbon and certain alloy steel wire rod (wire rod) from Mexico. The period of review (POR) is October 1... (the Act). \\1\\ See Carbon and Certain Alloy Steel Wire Rod From Mexico: Preliminary Results...

  6. 77 FR 66954 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2012-11-08

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Preliminary Results of... on carbon and certain alloy steel wire rod (wire rod) from Mexico. The period of review is October 1... Antidumping Duty Orders: Carbon and Certain Alloy Steel Wire Rod from Brazil, Indonesia, Mexico,...

  7. 77 FR 13545 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Notice of Final Results of Antidumping Duty...

    Science.gov (United States)

    2012-03-07

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Notice of Final Results... duty order on carbon and certain alloy steel wire rod (wire rod) from Mexico.\\1\\ This review covers.... \\1\\ See Carbon and Certain Alloy Steel Wire Rod from Mexico: Notice of Preliminary Results...

  8. 76 FR 33218 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Initiation of Anti-Circumvention Inquiry of...

    Science.gov (United States)

    2011-06-08

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Initiation of Anti... antidumping (AD) order on carbon and certain alloy steel wire rod from Mexico.\\1\\ See Notice of Antidumping Duty Orders: Carbon and Certain Alloy Steel Wire Rod from Brazil, Indonesia, Mexico, Moldova,...

  9. 78 FR 33809 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of...

    Science.gov (United States)

    2013-06-05

    ... Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of China: Rescission...'') initiated an administrative review of the antidumping duty order on seamless carbon and alloy steel standard... order on seamless carbon and alloy steel standard, line, and pressure pipe from the People's Republic...

  10. 78 FR 16832 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation...

    Science.gov (United States)

    2013-03-19

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... corrosion-resistant carbon steel flat products (``CORE'') from Germany and the Republic of Korea (``Korea...-Year (``Sunset'') Review, 77 FR 85 (January 3, 2012). \\2\\ See Corrosion-Resistant Carbon Steel...

  11. 77 FR 24221 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission...

    Science.gov (United States)

    2012-04-23

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission... countervailing duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to...

  12. 77 FR 13093 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2012-03-05

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty (``CVD'') order on corrosion-resistant carbon steel flat... Review'' below. \\1\\ See Corrosion-Resistant Carbon Steel Flat Products from the Republic of...

  13. 77 FR 31877 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five...

    Science.gov (United States)

    2012-05-30

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five... duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to lead...

  14. 77 FR 301 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year...

    Science.gov (United States)

    2012-01-04

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year Reviews Concerning the Countervailing Duty Order on Corrosion-Resistant Carbon Steel Flat Products From Korea and the Antidumping Duty Orders on Corrosion-Resistant Carbon Steel Flat Products From Germany...

  15. 76 FR 77775 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-12-14

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... countervailing duty order on corrosion-resistant carbon steel flat products from the Republic of Korea covering the period January 1, 2009, through December 31, 2009. See Corrosion-Resistant Carbon Steel...

  16. 78 FR 55057 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-09

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea.... See Corrosion-Resistant Carbon Steel Flat Products from Germany and the Republic of Korea:...

  17. 76 FR 3613 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2011-01-20

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... review of the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE..., 2008. See Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea:...

  18. 77 FR 72827 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Final...

    Science.gov (United States)

    2012-12-06

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... on certain corrosion- resistant carbon steel flat products (``CORE'') from Germany and the Republic... Reviews'' section of this notice. \\1\\ Corrosion-Resistant Carbon Steel Flat Products From Germany and...

  19. Internal corrosion of carbon steel piping in hot aquifers service

    Directory of Open Access Journals (Sweden)

    Simičić Miloš V.

    2011-01-01

    Full Text Available Internal corrosion of carbon steel pipelines is a major problem encountered in water service. In terms of prediction of the remaining lifetime for water pipelines based on the corrosion allowance, the three main approaches are corrosion modelling, corrosion inhibitor availability, and corrosion monitoring. In this study we used two theoretical corrosion models, CASSANDRA and NORSOK M-506 of quite different origin in order to predict uniform corrosivity of hot aquifers in eight different pipelines. Because of the varying calculation criteria for the different models, these can give very different corrosion rate predictions for the same data input. This is especially true under conditions where the formation of protective films may occur, such as at elevated temperatures. The evaluation of models was conducted by comparison using weight-loss coupons and three corrosion inhibitors were obtained from commercial suppliers. The tests were performed during the 60-day period. Even though inhibitors’ efficiencies of 98% had been achieved in laboratory testing, inhibitors’ availabilities of 85% have been used due to logistics problems and other issues. The results, given in mmpy, i.e. millimeter per year, are very consistent with NORSOK M-506 prediction. This is presumably because the model considers the effect of the formation of a passive iron carbonate film at temperatures above 80 °C and significant reduction in corrosion rate. Corrosion inhibitor A showed a better performance than inhibitors B and C in all cases but the target corrosion rates of less than 0.1 mmpy were achieved for all inhibitors. The chemical type of corrosion inhibitor A is based on quaternary amines mixed with methanol, isopropyl alcohol, xylene and ethylbenzene. Based on the obtained results the carbon steel lifetime of 30 years, provided proper inhibitors are present and 3mm corrosion allowance, can be achieved for hot aquifers service with presented water compositions.

  20. Study on temper-rapid cooling process of low carbon steel produced by CSP

    Institute of Scientific and Technical Information of China (English)

    Huajie Wu; Yangchun Liu; Jie Fu

    2007-01-01

    On the basis of the effect of carbon precipitation on the microstructure and properties of steel products below A1 temperature,a new thermal treatment method (temper-rapid cooling process) was studied. By the temper-rapid cooling process, the yield strengths of the high strength low carbon (HSLC) steel ZJ330 and SPA-H produced using the compact strip production (CSP) process increased from 340 to about 410 MPa and from 410 to about 450 MPa, respectively. The results indirectly indicated that there existed nanoscaled iron-carbon precipitates that have obvious precipitation effect on low carbon steel produced by CSP. The prospect of application is discussed.

  1. Constitutive model depending upon temperature and strain rate of carbon constructional quality steels

    Institute of Scientific and Technical Information of China (English)

    杨柳; 罗迎社

    2008-01-01

    The basic factors relating to the rheological stress in the constitutive equations were introduced.Carbon constructional quality steels were regarded as a kind of elastic-viscoplastic materials under high temperature and the elastic-viscoplastic constitutive models were summarized.A series of tension experiments under the same temperature and different strain rates,and the same strain rate and different temperatures were done on 20 steel,35 steel and 45 steel.52 groups of rheological stress-strain curves were obtained.The experimental results were analyzed theoretically.The rheological stress constitutive models of carbon steels were built combining the strong points of the Perzyna model and Johnson-Cook model.Comparing the calculation results conducted from the model with the experiment results,the results proves that the model can reflect the temperature effect and strain rate effect of carbon constructional quality steels better.

  2. Stress-strain curves of steel and aluminium exposed to matural fires

    NARCIS (Netherlands)

    Maljaars, J.

    2010-01-01

    The temperature-dependent reduction factors on the yield stress in codes for steel structures, ky, are derived using a constant heating rate and a constant stress, where the influence of creep is implicitly taken into account. This paper considers the material properties of steel and aluminium on th

  3. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  4. Study of carbon steel corrosion layer by X-ray diffraction and absorption methods

    Energy Technology Data Exchange (ETDEWEB)

    Malinovschi, V. [University of Pitesti, Research Center for Advanced Materials, Targul din Vale Street, No.1, 110040 Pitesti, Arges (Romania)]. E-mail: malinov@electra.upit.ro; Ducu, C. [University of Pitesti, Research Center for Advanced Materials, Targul din Vale Street, No.1, 110040 Pitesti, Arges (Romania); Aldea, N. [National Institutes for Research and Development for Isotopic and Molecular Technologies, P.O. Box 700, 3400 Cluj-Napoca (Romania); Fulger, M. [Institutes for Nuclear Research, P.O. Box 0402, 0300 Pitesti (Romania)

    2006-06-30

    To predict the behavior of structural metallic materials into the CANDU nuclear reactor, the oxide films on the surface were growth in a controlled manner using an autoclave simulating the environment specific to the nuclear reactor. In order to establish the structural changes of the oxide films, the X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and extended X-ray absorption fine structure spectroscopy (EXAFS) analysis were used. Analysis performed showed differences in morphology of the oxide films from carbon steel samples exposed under different conditions corresponding to primary and secondary circuits in CANDU nuclear reactor. The oxide phases were identified and the thicknesses of the films were calculated. The agreement between results obtained by these methods was discussed according to the microstructure of the samples.

  5. Fatigue Property of Nano-grained Delaminated Low-carbon Steel Sheet

    Institute of Scientific and Technical Information of China (English)

    X. Li; T.F. Jing; M.M. Lu; R. Xu; B.Y. Liang; J.W. Zhang

    2011-01-01

    Tension-tension fatigue life tests on nano-grained delaminated Iow-carbon steel sheet under different fatigue loads are carried out to study the fatigue properties of the steel. The three-dimensional microstructures of the steel are observed by TEM. In addition, the morphology of the fatigue fracture of the specimen under different loads is observed by SEM. The results show that micro-cracks form on the weak interface of the nano-grained steel under Iow-stress conditions, which hinders the propagation of the main cracks and reduces the fatigue crack propagation rate, resulting in the extending fatigue life of the steel.

  6. STUDY OF THE HARDENING TEMPERATURE INFLUENCE ON PROCESSES WHEN TEMPERING CARBON STEEL

    Directory of Open Access Journals (Sweden)

    Ms. Irina L. Polyanskaya

    2016-12-01

    Full Text Available The article presents the research results of carbon steel electrical resistance changes at low tem-pering and determines the effect of temperature on the electrical resistance. The analysis of the results showed that the influence of carbon on the value of the electrical resistance is higher than the influence of the crystal structure defects. The changes of the hardened steel electrical resistance are due to the redistri-bution of carbon.

  7. Simple Predicting Method for Fatigue Crack Growth Rate Based on Tensile Strength of Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Three types of fatigue tests for an annealed carbon steel containing carbon of 0.42 % were carried out on smooth specimens and specimens with a small blind hole in order to investigate the fatigue crack growth law. A simple predicting method for crack growth rates has been proposed involving strength σb and the relation between cyclic stress and strain. The validity of proposed method has been confirmed by experiments on several carbon steels with different loadings.

  8. Effect of Carbon Properties on Melting Behavior of Mold Fluxes for Continuous Casting of Steels

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance,steel quality and environment of casting operation. The high temperature microscopy technique was used to investigate the melting behaviour of mold fluxes, and drip test method was used to determine their melting rate. The results showed that free carbon is a dominant factor in governing the melting behaviour of fluxes, and the melting rate is increased with increasing carbon reactivity and decreasing carbon content.

  9. Study on rolling process optimization of high carbon steel wire

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The existing problems in the manufacture of SWRH82B high carbon steel wire were discussed by sampling and testing the microstructure and properties of the steel from the workshop. To solve the problems, the experimental parameters for thermal simulation were optimized, and the thermal simulating experiments were carried out on a Gleeble1500 thermal simulator. The process parameters for the manufacture were optimized after analysis of the data, and the productive experiments were performed after the water box in front of the no-twist blocks was reconstructed, to control the temperature of the loop layer. The results from the productive experiments showed that the cooling rate of 10-15 ℃/s was reasonable before phase transformation, about 5℃/s during phase wire was increased to 1150-1170 MPa with an increase of 20-30 MPa, the percentage reduction of section was to 34%-36% with an increase of 1%-3% by testing the finished products after reconstruction.

  10. Aluminizing of plain carbon steel: Effect of temperature on coating and alloy phase morphology at constant holding time

    OpenAIRE

    Isiko, Maureen Bangukira

    2012-01-01

    Aluminized steel possesses excellent physical, chemical and mechanical properties as compared to plain carbon steel. This type of steel has found application in high temperature, oxidizing and corrosive environments. In addition, aluminized steel is more cost effective than stainless steels. The objective of the current study is to study effect of temperature on the thicknesses and phase morphology of the coating and intermetallic layer that is formed during hot-dip aluminizing of steel at a ...

  11. FINITE DIFFERENCE SIMULATION OF LOW CARBON STEEL MANUAL ARC WELDING

    Directory of Open Access Journals (Sweden)

    Laith S Al-Khafagy

    2011-01-01

    Full Text Available This study discusses the evaluation and simulation of angular distortion in welding joints, and the ways of controlling and treating them, while welding plates of (low carbon steel type (A-283-Gr-C through using shielded metal arc welding. The value of this distortion is measured experimentally and the results are compared with the suggested finite difference method computer program. Time dependent temperature distributions are obtained using finite difference method. This distribution is used to obtain the shrinkage that causes the distortions accompanied with structural forces that act to modify these distortions. Results are compared with simple empirical models and experimental results. Different thickness of plates and welding parameters is manifested to illustrate its effect on angular distortions. Results revealed the more accurate results of finite difference method that match experimental results in comparison with empirical formulas. Welding parameters include number of passes, current, electrode type and geometry of the welding process.

  12. Electric arc surfacing on low carbon steel: Structure and properties

    Science.gov (United States)

    Ivanov, Yurii; Gromov, Victor; Kormyshev, Vasilii; Konovalov, Sergey; Kapralov, Evgenii; Semin, Alexander

    2016-11-01

    By the methods of modern materials science, the structure-phase state and microhardness distribution along the cross-section of single and double coatings surfaced on martensite low carbon steel by alloy powder-cored wire were studied. It was established that the increased mechanical properties of surfaced layer are determined by the sub-micro and nanodispersed martensite structure formation, containing iron borides forming the eutectic of lamellar form. The plates of Fe2B are formed mainly in the eutectic of a single-surfaced layer, while FeB is formed in a double-surfaced layer. The existence of bend extinction contours indicating the internal stress fields formation at the boundaries of Fe borides-α-Fe phases were revealed.

  13. Subgrains and boron distribution of low carbon bainitic steels

    Institute of Scientific and Technical Information of China (English)

    Xuemin Wang; Bing Cao; Chengjia Shang; Xueyi Liu; Xinlai He

    2005-01-01

    The structure variation of deformed austenite during the relaxation stage after deformation at various temperatures in an Nb-B ultra low carbon bainitic steel and Fe-Ni alloy was studied by the thermo-simulation. Optical microscope and TEM were applied to analyze the microstructure after RPC (Relaxation-precipitation-controlling phase transformation technique) and the evolution of dislocation configuration. The particle tracking autoradiography (PTA) technique, revealing the distribution of boron, was employed to show the change of boron segregation after different relaxation times. The results indicate that during the relaxation stage the recovery occurs in the deformed austenite, the dislocations rearrange and subgrains form. During the subsequent cooling the boron will segregate at the boundaries of subgrains.

  14. Corrosion inhibition of carbon steel by sodium metavanadate

    Directory of Open Access Journals (Sweden)

    VIJAYA GOPAL SRIBHARATHY

    2012-08-01

    Full Text Available The inhibition efficiency of sodium metavanadate (SMV-adipic acid (AA system in controlling corrosion of carbon steel in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight-loss method; 250 ppm of SMV exhibits inhibition efficiency of 56 %. Addition of adipic acid to SMV improves the inhibition efficiency of the system. The formulation consisting of 250 ppm of SMV and 250 ppm of adipic acid has inhibition efficiency of 98 %. A synergistic effect exists between SMV and adipic acid with the synergism parameters greater than 1. Mecha¬nistic aspects of corrosion inhibition have been studied by electrochemical methods like potentiodynamic polarization and electrochemical impedance spectroscopy. FTIR spectra reveal that the protective film consists of Fe2+-SMV complex and Fe2+-adipic acid complex. The protective film has been analyzed by fluorescence spectra, SEM and EDAX.

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

    OpenAIRE

    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 o...

  16. Energy use and carbon dioxide emissions in the steel sector in key developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Price, L.K.; Phylipsen, G.J.M.; Worrell, E.

    2001-04-01

    Iron and steel production consumes enormous quantities of energy, especially in developing countries where outdated, inefficient technologies are still used to produce iron and steel. Carbon dioxide emissions from steel production, which range between 5 and 15% of total country emissions in key developing countries (Brazil, China, India, Mexico, and South Africa), will continue to grow as these countries develop and as demand for steel products such as materials, automobiles, and appliances increases. In this report, we describe the key steel processes, discuss typical energy-intensity values for these processes, review historical trends in iron and steel production by process in five key developing countries, describe the steel industry in each of the five key developing countries, present international comparisons of energy use and carbon dioxide emissions among these countries, and provide our assessment of the technical potential to reduce these emissions based on best-practice benchmarking. Using a best practice benchmark, we find that significant savings, in the range of 33% to 49% of total primary energy used to produce steel, are technically possible in these countries. Similarly, we find that the technical potential for reducing intensities of carbon dioxide emissions ranges between 26% and 49% of total carbon dioxide emissions from steel production in these countries.

  17. Influence of Heat Treatments on the Corrosion Resistance of Medium -Carbon Steel using Sulfuric Spring Water

    Directory of Open Access Journals (Sweden)

    Ikhlas Basheer

    2013-04-01

    Full Text Available The corrosion is one of the important problems that may be occur to the parts of machinery and equipment after manufactured and when used as a result of exposure to corrosive media. Plain-carbon steel is considered as one of the most common minerals used in industrial applications. Some of heat treatments can have direct effect on the corrosion rate of steel by building up galvanic corrosion cells between its microscopic phases. Therefore, to adopt one of kinds of the plain-carbon steel and the most commonly used in industry to be study subject, that is medium carbon steel and took samples of this steel has been treated thermally in three methods which the normalising, annealing, and hardening .The corrosive media used in the research is Sulfuric Spring, it contains many chemical compounds to show its influence on the corrosion of steel. The weight loss method is used to determine corrosion rate and to compare between the results obtained, show that the greatest corrosion resistance of the annealed steel and the corrosion resistance of the hardened steel is the lowest while the corrosion  resistance of the normalised steel is in-between them.         Calcium carbonate was formed on the metal surface which acts as an isolating layer which decrease corrosion rate with time

  18. Three Heavy Reflector Experiments in the IPEN/MB-01 Reactor: Stainless Steel, Carbon Steel, and Nickel

    Science.gov (United States)

    dos Santos, A.; de Andrade e Silva, G. S.; Mura, L. F.; Fuga, R.; Jerez, R.; Mendonça, A. G.

    2014-04-01

    The heavy reflector experiments performed in the IPEN/MB-01 research reactor facility comprise a set of critical configurations employing the standard 28×26-fuel-rod configuration. The heavy reflector, either Stainless Steel, Carbon Steel or Nickel plates, was placed at the west face of this reactor. 32 plates around 3.0 mm thick were used in all the experiments. The aim was to provide high quality experimental data for the interpretation and validation of the SS-304 heavy reflector calculation methods. The experiments of Carbon Steel, which is composed mainly of iron, and Nickel were performed to provide a consistent and an interpretative check to the SS-304 reflector measurements. The experimental data comprise a set of critical control bank positions, temperatures and reactivities as a function of the number of the plates. The competition between the effect of thermal neutron capture in the heavy reflector and the effect of fast neutrons back scattering to the core is highlighted by varying the reflector thickness. For the Carbon Steel case the reactivity gain when all the 32 plates are inserted is the smallest one, thus demonstrating that Carbon Steel or essentially iron does not have the same reflector properties as the Stainless Steel or Nickel plates do. Nickel has the highest reactivity gain, thus demonstrating that this material is better reflector than Iron and Stainless Steel. The theoretical analysis was performed by MCNP-5 with the nuclear data library ENDF/B-VII.0. It was shown that this library has a very good performance up to thirteen plates and overestimates the reactivity for higher number of plates independently of the type of the reflector.

  19. Hot deformation behavior of medium carbon V-N microalloyed steel

    Institute of Scientific and Technical Information of China (English)

    XU Lei; WANG Cheng-yang; LIU Guo-quan; BAI Bing-zhe

    2009-01-01

    Processing maps for a medium carbon V-N microalloyed steel(designated as VN steel) and a medium carbon V-N bared steel(designated as Non-VN steel) were developed to study the hot deformation behavior and the influence of vanadium and nitrogen,in the temperature range of 750-1 100 ℃ and strain rate range of 0.005-30 s~(-1).Experimental results show that the processing map for the VN steel exhibits two dynamic recrystallization and three instability domains,while that for the Non-VN steel has one dynamic recrystallization and three instability domains.The instability domains of VN steel are larger than those of the Non-VN steel,and the VN steel is easier to be unstable when being hot deformed at high temperature and high stain rate.The addition and precipitation of vanadium and nitrogen can hinder the dynamic recrystallization.Compared with the Non-VN steel,the VN steel has higher dynamic recrystallization critical strain and the corresponding stress.

  20. Development of Low and Middle Carbon Martensite Spring Steel with High Strength and Toughness for Automobile

    Institute of Scientific and Technical Information of China (English)

    Li Ye-sheng; Wu Zi-ping; Zhu Yin-lu; Chen Hui-huang

    2004-01-01

    The conventional middle and high carbon spring steels have some drawbacks in properties, production and application. In order to meet the demands of rapid development of automobile, a new low and middle carbon spring steel35Si2CrMnVB, C0.34, Sil.66, Mn0.80, Cr0.67, V0.13, B0.001, P0.011, S0.014 wt.%, has been developed. Comparison between the new spring steel 35Si2CrMnVB and the conventional spring steel 60Si2MnA, C0.61, Sil.75, Mn0.76, P0.021,S0.018 wt.%, shows that the new spring steel has not only high strength, good ductility, good comprehensive mechanical properties, but also low decarbonization tendency, sufficient hardenability and high elastic sag resistance, etc.. The microstructure change in quenched steel caused by the decreasing of carbon contents is detected through metallographic observation, the new low and middle carbon spring steel 35Si2CrMnVB after quenching is composed of almost lath martensite with high dislocation density and only a little martensite with twin structure. It is testified that to develop low carbon spring steel with more excellent properties for automobile is feasible.

  1. Fatigue Life Estimation of Medium-Carbon Steel with Different Surface Roughness

    Directory of Open Access Journals (Sweden)

    Changyou Li

    2017-03-01

    Full Text Available Medium-carbon steel is commonly used for the rail, wire ropes, tire cord, cold heading, forging steels, cold finished steel bars, machinable steel and so on. Its fatigue behavior analysis and fatigue life estimation play an important role in the machinery industry. In this paper, the estimation of fatigue life of medium-carbon steel with different surface roughness using established S-N and P-S-N curves is presented. To estimate the fatigue life, the effect of the average surface roughness on the fatigue life of medium-carbon steel has been investigated using 75 fatigue tests in three groups with average surface roughness (Ra: 0.4 μm, 0.8 μm, and 1.6 μm, respectively. S-N curves and P-S-N curves have been established based on the fatigue tests. The fatigue life of medium-carbon steel is then estimated based on Tanaka-Mura crack initiation life model, the crack propagation life model using Paris law, and material constants of the S-N curves. Six more fatigue tests have been conducted to validate the presented fatigue life estimation formulation. The experimental results have shown that the presented model could estimate well the mean fatigue life of medium-carbon steel with different surface roughness.

  2. Effect of Stress Relief Annealing on Microstructure & Mechanical Properties of Welded Joints Between Low Alloy Carbon Steel and Stainless Steel

    Science.gov (United States)

    Nivas, R.; Das, G.; Das, S. K.; Mahato, B.; Kumar, S.; Sivaprasad, K.; Singh, P. K.; Ghosh, M.

    2017-01-01

    Two types of welded joints were prepared using low alloy carbon steel and austenitic stainless steel as base materials. In one variety, buttering material and weld metal were Inconel 82. In another type, buttering material and weld metal were Inconel 182. In case of Inconel 82, method of welding was GTAW. For Inconel 182, welding was done by SMAW technique. For one set of each joints after buttering, stress relief annealing was done at 923 K (650 °C) for 90 minutes before further joining with weld metal. Microstructural investigation and sub-size in situ tensile testing in scanning electron microscope were carried out for buttered-welded and buttered-stress relieved-welded specimens. Adjacent to fusion boundary, heat-affected zone of low alloy steel consisted of ferrite-pearlite phase combination. Immediately after fusion boundary in low alloy steel side, there was increase in matrix grain size. Same trend was observed in the region of austenitic stainless steel that was close to fusion boundary between weld metal-stainless steel. Close to interface between low alloy steel-buttering material, the region contained martensite, Type-I boundary and Type-II boundary. Peak hardness was obtained close to fusion boundary between low alloy steel and buttering material. In this respect, a minimum hardness was observed within buttering material. The peak hardness was shifted toward buttering material after stress relief annealing. During tensile testing no deformation occurred within low alloy steel and failure was completely through buttering material. Crack initiated near fusion boundary between low alloy steel-buttering material for welded specimens and the same shifted away from fusion boundary for stress relieved annealed specimens. This observation was at par with the characteristics of microhardness profile. In as welded condition, joints fabricated with Inconel 82 exhibited superior bond strength than the weld produced with Inconel 182. Stress relief annealing

  3. Recent Progress in High Strength Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    Zrník J.

    2006-01-01

    Full Text Available Advanced High Strength (AHS steels, among them especially Dual Phase (DP steels, Transformation Induced Plasticity (TRIP steels, Complex Phase (CP steels, Partially Martensite (PM steels, feature promising results in the field. Their extraordinary mechanical properties can be tailored and adjusted by alloying and processing. The introduction of steels with a microstructure consisting at least of two different components has led to the enlargement of the strength level without a deterioration of ductility. Furthermore, the development of ultra fine-grained AHS steels and their service performance are reviewed and new techniques are introduced. Various projects have been devoted to develop new materials for flat and long steel products for structural applications. The main stream line is High Strength, in order to match the weight lightening requirements that concern the whole class of load bearing structures and/or steel components and one of the most investigated topics is grain refinement.

  4. Local hardening evaluation of carbon steels by using frequency sweeping excitation and spectrogram method

    Science.gov (United States)

    Tsuchida, Yuji; Kudo, Yuki; Enokizono, Masato

    2017-02-01

    This paper presents our proposed frequency sweeping excitation and spectrogram method (FSES method) by a magnetic sensor for non-destructive testing of hardened low carbon steels. This method can evaluate the magnetic properties of low carbon steels which were changed after induction heating treatment. It was examined by our proposed method that the degrees of yield strength of low carbon steels were varied depending on hardened conditions. Moreover, it was made clear that the maximum magnetic field strength, Hmax, derived from the measured B-H loops was very sensitive to the hardening if the surface of the samples were flat.

  5. SURFACE ROUGHNESS AND CUTTING FORCES IN CRYOGENIC TURNING OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    T. C. YAP

    2015-07-01

    Full Text Available The effect of cryogenic liquid nitrogen on surface roughness, cutting forces, and friction coefficient of the machined surface when machining of carbon steel S45C in wet, dry and cryogenic condition was studied through experiments. The experimental results show that machining with liquid nitrogen increases the cutting forces, reduces the friction coefficient, and improves the chips produced. Beside this, conventional machining with cutting fluid is still the most suitable method to produce good surface in high speed machining of carbon steel S45C whereas dry machining produced best surface roughness in low speed machining. Cryogenic machining is not able to replace conventional cutting fluid in turning carbon steel.

  6. THE ELECTROCHEMICAL BEHAVIOR OF OCEANIC MICROBIOLOGICAL INFLUENCED CORROSION ON CARBON STEEL

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The corrosion behavior of carbon steel in the medium of marine microorganisms was investigated by electrochemical impedance spectra, polarization curves, and so on. Experimental results showed that the corrosion potential of carbon steel moved in a negative direction in the unpurified marine microorganism solution, and the polarization style of the cathodic process did not change. The electrochemical impedance spectra showed that the impedance value of the electrode decreased in the medium with bacteria, which indicated that the existence of microorganism could accelerate the corrosion progress of carbon steel.

  7. Creep testing and viscous behavior research on carbon constructional quality steel under high temperature

    Institute of Scientific and Technical Information of China (English)

    余敏; 罗迎社; 彭相华

    2008-01-01

    Creep tests under at a certain temperature and different stress levels were performed on two carbon constructional quality steels at a certain stress level and different temperatures,and their creep curves at high temperature were obtained based on analyzing the testing data.Taking 45 steel at a certain temperature and stress as the example,the integral creep constitutive equation and the differential stress-strain constitutive relationship were established based on the relevant rheological model,and the integral core function was also obtained.Simultaneously,the viscous coefficients denoting the viscous behavior in visco-plastic constitutive equation were determined by taking use of the creep testing data.Then the viscous coefficients of three carbon steels(20 steel,35 steel and 45 steel) were compared and analyzed.The results show that the viscosity is different due to different materials at the same temperature and stress.

  8. Modeling of a self-healing process in blast furnace slag cement exposed to accelerated carbonation

    NARCIS (Netherlands)

    Zemskov, S.V.; Ahmad, B.; Copuroglu, O.; Vermolen, F.J.

    2013-01-01

    In the current research, a mathematical model for the post-damage improvement of the carbonated blast furnace slag cement (BFSC) exposed to accelerated carbonation is constructed. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate, whi

  9. 75 FR 64254 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products From Brazil; Final Results of...

    Science.gov (United States)

    2010-10-19

    ... degassed, fully stabilized (commonly referred to as interstitial-free (IF)) steels, high strength low alloy... and nitrogen elements. HSLA steels are recognized as steels with micro- alloying levels of elements... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products From...

  10. 78 FR 42039 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2013-07-15

    ..., fully stabilized (commonly referred to as interstitial-free (``IF'')) steels, high strength low alloy... columbium), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels... stabilized; high strength low alloy; and the substrate for motor lamination steel may also enter under...

  11. 78 FR 64473 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Final No...

    Science.gov (United States)

    2013-10-29

    ..., fully stabilized (commonly referred to as interstitial-free (``IF'')) steels, high strength low alloy... columbium), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels... stabilized; high strength low alloy; and the substrate for motor lamination steel may also enter under...

  12. New low-carbon steel for hot, warm, or cold forging

    Energy Technology Data Exchange (ETDEWEB)

    Ollilainen, V.; Hocksell, E. [Imatra Steel Oy Ab, Imatra Steelworks (Finland)

    2000-05-01

    The development of a new high-strength steel started from the needs of cold forging and continued into hot- and warm-forging areas. The steel has a very low carbon content (<0.1% C) and chromium-boron alloying. Its hardening is simple: just water quenching without tempering. Hot forgings of this steel are directly quenched from forging temperature, resulting in process cost savings and weight reduction. (orig.)

  13. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  14. 77 FR 21968 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of...

    Science.gov (United States)

    2012-04-12

    ... International Trade Administration Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the... and alloy steel standard, line, and pressure pipe from the People's Republic of China. The period of... countervailing duty order on seamless carbon and alloy steel standard, line, and pressure pipe from the...

  15. 75 FR 27297 - Certain Hot-Rolled Carbon Steel Flat Products from India: Notice of Final Results of Antidumping...

    Science.gov (United States)

    2010-05-14

    ...- degassed, fully stabilized (commonly referred to as interstitial-free ``IF'')) steels, high-strength low... to as columbium), or both, added to stabilize carbon and nitrogen elements. HSLA steels are... International Trade Administration Certain Hot-Rolled Carbon Steel Flat Products from India: Notice of...

  16. Carbonation of steel slag for CO2 sequestration: Leaching of products and reaction mechanisms

    NARCIS (Netherlands)

    Huijgen, W.J.J.; Comans, R.N.J.

    2006-01-01

    Carbonation of industrial alkaline residues can be used as a CO2 sequestration technology to reduce carbon dioxide emissions. In this study, steel slag samples were carbonated to a varying extent. Leaching experiments and geochemical modeling were used to identify solubility-controlling processes of

  17. Origin of abnormal formation of pearlite in medium-carbon steel under nonequilibrium conditions of heating

    Science.gov (United States)

    Mirzaev, D. A.; Yakovleva, I. L.; Tereshchenko, N. A.; Urtsev, V. N.; Degtyarev, V. N.; Shmakov, A. V.

    2016-06-01

    The structure and kinetics of the formation of austenite in medium-carbon steel during shortterm heating above the temperature Ac 1 followed by accelerated cooling are analyzed. It has been shown that the abnormal formation of pearlite in steel results from the concentrational and structural inhomogeneity of austenite, as well as the presence of carbide particles in ferrite areas.

  18. Solidification Structure of Low Carbon Steel Strips with Different Phosphorus Contents Produced by Strip Casting

    Institute of Scientific and Technical Information of China (English)

    Na LI; Zhenyu LIU; Yiqing QIU; Zhaosen LIN; Xianghua LIU; Guodong WANG

    2006-01-01

    In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.

  19. Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

    NARCIS (Netherlands)

    Hu, J.; Koleva, D.A.; De Wit, J.H.W.; Kolev, H.; Van Breugel, K.

    2011-01-01

    This study presents the results on the investigation of the corrosion behavior of carbon steel in model alkaline medium in the presence of very low concentration of polymeric nanoaggregates [0.0024 wt % polyethylene oxide (PEO)113-b-PS70 micelles]. The steel electrodes were investigated in chloride

  20. CYCLIC RECRYSTALLIZATION OF FERRITE IN HOT-ROLLED LOW-CARBON SHEET STEEL WITH STRUCTURETEXTURAL HETEROGENEITY

    Directory of Open Access Journals (Sweden)

    A. M. Nesterenko

    2009-01-01

    Full Text Available It is determined that in the process of soaking at subcritical temperature 680 °C in hot-rolled rolling of low-carbon steel 08 ps recrystallization is developed with heterogeneous fu ll repeat change of the steel ferrite change by its section.

  1. Microbial Methane Production Associated with Carbon Steel Corrosion in a Nigerian Oil Field.

    Science.gov (United States)

    Mand, Jaspreet; Park, Hyung S; Okoro, Chuma; Lomans, Bart P; Smith, Seun; Chiejina, Leo; Voordouw, Gerrit

    2015-01-01

    Microbially influenced corrosion (MIC) in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  2. Microbial methane production associated with carbon steel corrosion in a Nigerian oil field

    Directory of Open Access Journals (Sweden)

    Jaspreet eMand

    2016-01-01

    Full Text Available Microbially influenced corrosion (MIC in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  3. Behavior of AISI SAE 1020 Steel Implanted by Titanium and Exposed to Bacteria Sulphate Deoxidizer

    Science.gov (United States)

    Niño, Ely Dannier V.; Garnica, Hernán; Dugar-Zhabon, Veleriy; Castillo, Genis

    2014-05-01

    A hybrid technology to treat solid surfaces with the pulse high voltage and electric arc discharges of low pressure with a three-dimensional ion implantation technique (3DII) is applied. This technology is used to protect AISI SAE 1020 steel against a microbiological corrosion. The titanium ion implanted steel samples (coupons) are subjected to a medium of bacteria sulphate deoxidizer (BSD) which are very typical of the hydrocarbon industry and are potentially harmful for structures when are in contact with petroleum and some of its derivatives. The used technology aims to find an effective hybrid procedure to minimize the harmful effects of bacteria on AISI SAE 1020 steel. The hybrid technology efficiency of superficial titanium implantation is estimated through the measurements of the point corrosion characteristics obtained after testing both the treated and non-treated coupons. The three-dimensional surface structures of the samples are reconstructed with help of a confocal microscope.

  4. Polysaccharide from Plantago as a green corrosion inhibitor for carbon steel in 1M HCl solution.

    Science.gov (United States)

    Mobin, Mohammad; Rizvi, Marziya

    2017-03-15

    Polysaccharide from Plantago ovata was investigated for its inhibition characteristics for carbon steel corrosion in 1M HCl. The mucilage of the Plantago is comprised of a highly branched polysaccharide, arabinosyl (galaturonic acid) rhamnosylxylan (AX), which is mainly responsible for the corrosion inhibition of the carbon steel. The techniques that were used to assess the inhibition and adsorption properties of the AX in the acid solution are gravimetric method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-vis spectroscopy and FTIR. Thermodynamic and activation parameters revealed that the spontaneous adsorption of AX on carbon steel was mixed type and predominantly chemical in nature. Quantum chemical analysis supports the proposed mechanism of inhibition. AX from Plantago could serve as a green corrosion inhibitor for the carbon steel in hydrochloric medium with good inhibition efficiency but low risk of environmental pollution.

  5. Evaluation of long-term corrosion durability and self-healing ability of scratched coating systems on carbon steel in a marine environment

    Science.gov (United States)

    Zhao, Xia; Chen, Changwei; Xu, Weichen; Zhu, Qingjun; Ge, Chengyue; Hou, Baorong

    2016-09-01

    Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications. A composite coating system, including a primer, middle coat and topcoat, were used to protect carbon steel from corrosion in a marine environment. Two environmental additives, glass fibers and thiourea, were applied in the middle coat to modify the coating system. The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods. Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.% fibers and 0.5 wt.% thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5% NaCl for 120 d. Evolution of localized corrosion factors with time, as obtained from the current distribution showed that fibers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development significantly. Surface characterization suggested that adequate thiourea could be absorbed uniformly on fibers for a long time to play an important role in protecting the carbon steel. Finally, schematic models were established to demonstrate the action of fibers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.

  6. Hybrid use of steel and carbon-fiber reinforced concrete for monitoring of crack behavior

    OpenAIRE

    Ding, Yining; Han, Z; Zhang, Y; Azevedo, Cecília Maria

    2012-01-01

    In order to study the damage after concrete cracking, the influence of the combined use of steel fiber and carbon fiber on the conductivity and crack resistance of concrete beam under flexural loading were investigated. Carbon fiber and steel fiber were added as diphasic conductive materials to produce the electric conductive and ductile concrete. This paper reports the experimental and analytical work associated with establishing the crack width in relation to the fractional c...

  7. Prediction of Hot Ductility of Low-Carbon Steels Based on BP Network

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The purpose of the research is to obtain an effective method to predict the hot ductility of low-carbon steels, which will be a re ference to evaluate the crack sensitivity of steels. Several sub-netwo rks modeled from BP network were constructed for different temperature use, and the measured reduction of area (AR) of 12 kinds of low-carbo n steels under the temperature of 600 to 1000℃ were processed as trai ning samples. The result of software simulation shows that the model e stablished is relatively effective for predicting the hot ductility of steels.

  8. Microstructure and Mechanical Properties of a Dissimilar Friction Stir Weld between Austenitic Stainless Steel and Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    M.Jafarzadegan; A.Abdollah-zadeh; A.H.Feng; T.Saeid; J.Shen; H.Assadi

    2013-01-01

    Dissimilar fusion welding of austenitic stainless steels to carbon steels has some metallurgical and technical problems.It was suggested that the solid-state nature of friction stir welding (FSW) can overcome these problems and produce a sound weld with reliable mechanical properties.In this study,plates of 304 stainless steel and st37 steel were welded together by FSW at tool rotational speed of 600 r/min and welding speed of 50 mm/min.In the stir zone (SZ) of 304 stainless steel,the results showed a refined grain structure with some features of metadynamic recrystallization.In the SZ of st37 steel,the hot deformation of material in the austenite region produced small austenite grains.These grains transformed to fine ferrite and pearlite by cooling the material after FSW.The production of fine grains increased the hardness and tensile strength in the SZ of both sides with respect to their base metals (BMs).

  9. Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

  10. Determination of free nitrogen in carbon steels by inert gas fusion method

    Science.gov (United States)

    Tabakov, Ya. I.; Grigorovich, K. V.; Mansurova, E. R.

    2016-07-01

    The possibility to use hot extraction (thermal extraction in a carrier-gas flow) for fractional analysis of nitrogen in carbon steels is shown for cord and reinforcing-bar steels. A rapid procedure is developed for an analysis of free nitrogen in carbon steels. The validity of the analytical procedure is confirmed by high-temperature hydrogen extraction. The data obtained by the two methods correlate well with each other. A sample preparation procedure is developed for the determination of the content of dissolved nitrogen.

  11. The effect of carbon content on the structure-property of HSLA-100 steels

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C.I.; Mujahid, M.; DeArdo, A.J. [Univ. of Pittsburgh, PA (United States). Basic Metals Processing Research Inst.

    1995-12-31

    A major attraction of modern structural steels is their ability to offer a reduction in fabrication costs without compromising the quality and performance of the structure. For example, the relatively new family of high strength low alloy (HSLA-100) steels with copper additions features a reduction in the carbon content which leads to subsequent improvements in toughness and weldability. The strength in these steels is derived from a highly dislocated aged martensite and the precipitation of Cu particles which retards the softening associated during the aging process. Formation of austenite is also observed during aging around 640 C which is indicative of the low Ac{sub 1} temperature for this kind of steel composition. The purpose of this paper was to study the effect of carbon content on the structure-property relation of HSLA-100 steels.

  12. Effect of Cr, Mo and W on the Microstructure of Al Hot Dipped Carbon Steels

    Energy Technology Data Exchange (ETDEWEB)

    Trung, Trinh Van [School of Materials Science and Engineering, Hanoi University of Science and Technology, Hanoi (Viet Nam); Kim, Min Jung; Park, Soon Yong; Vadav, Poonam; Abro, Muhammad Ali; Lee, Dong Bok [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-02-15

    A low carbon steel, Fe-2.25%Cr steel (ASTM T22), and Fe-2.25%Cr-1.6%W steel (ASTM T23) were aluminized by hot dipping into molten Al baths. After hot-dipping, a thin Al-rich topcoat and a thick alloy layer formed on the surface. The topcoat consisted primarily of a thin Al layer that contained a small amount of Fe, whereas the alloy layer consisted of Al-Fe intermetallics such as Al{sub 5}Fe{sub 2} and AlFe. Cr, Mo, and W in T22 and T23 steels reduced the thickness of the topcoat and the alloy layer, and flattened the reaction front of the aluminized layer, when compared to the low carbon steel.

  13. Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

    Science.gov (United States)

    Wan, Long; Huang, Yong-xian; Lü, Shi-xiong; Huang, Ti-fang; Lü, Zong-liang

    2016-08-01

    In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid-solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation (LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.

  14. The structural dependence of work hardening in low carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.E.

    1991-12-01

    The influence of the dislocation cell structure on the work hardening behavior of low carbon steel sheets was investigated. Specimens were prestrained at low temperature to suppress cell formation and their subsequent behavior was compared with results of isothermal reference tests. It was found that the extent of cell development has little or no influence on the plastic behavior at room temperature and below. Interrupted temperature, tensile-shear tests demonstrated further that the transient behavior induced by loading path changes is also not strongly associated with the cell walls. In-situ straining studies indicate that the factor controlling the flow stress at room temperature is the limited mobility of screw dislocations moving the cell interiors, and not dislocation interactions with the cell walls. The unique properties of a/2<111> screw dislocations are known to dominate low temperature deformation behavior in bcc metals. The current work indicates that these dislocations may still control the flow stress at intermediate temperatures, even in the presence of a developed cell structure.

  15. Elucidation of mechanism wear carbon steel with structure of martensite

    Directory of Open Access Journals (Sweden)

    I. A. Vakulenko

    2013-04-01

    Full Text Available Purpose. The purpose of the paper is an estimation of degree of metal hardness change for the railway wheel with martensite structure during rolling. Methodology. As strength characteristic the Rockwell hardness is used. Wear tests were conducted in the conditions of normal loading with (10% and without sliding on the test equipment SMTs-2. Parameters of the fine crystalline structure (tetragonality degree of the crystalline grid, dislocation density, scale of coherent scattering regions, and disturbance value of the crystalline grid of second kind are determined by the methods of X-ray structural analysis. Findings. During operation of the railway wheels with different strength level, origin of defects on the wheel thread is caused by simultaneous action of both the friction forces and the cyclically changing loadings. Considering that formation of damage centers is largely determined by the state of metal volumes near the wheel thread, one should expect the differences in friction processes development at high contact stress for the wheels with different strength level and structural state. Originality. During the wear tests softening effect of carbon steel with martensite quenching structure is obtained. Softening effect equaled 3.5–7% from the level of quenched metal hardness. The softening effect is accompanied by the reduction of tetragonality degree of the crystalline structure of martensite, reduction of coherent scattering regions, dislocation density increase and crystalline grid disturbance of the second kind. Practical value. The results point out the necessity for further studies to clarify the resulted softening effect mechanism.

  16. Parameters Optimization of Low Carbon Low Alloy Steel Annealing Process

    Institute of Scientific and Technical Information of China (English)

    Maoyu ZHAO; Qianwang CHEN

    2013-01-01

    A suitable match of annealing process parameters is critical for obtaining the fine microstructure of material.Low carbon low alloy steel (20CrMnTi) was heated for various durations near Ac temperature to obtain fine pearlite and ferrite grains.Annealing temperature and time were used as independent variables,and material property data were acquired by orthogonal experiment design under intercritical process followed by subcritical annealing process (IPSAP).The weights of plasticity (hardness,yield strength,section shrinkage and elongation) of annealed material were calculated by analytic hierarchy process,and then the process parameters were optimized by the grey theory system.The results observed by SEM images show that microstructure of optimization annealing material are consisted of smaller lamellar pearlites (ferrite-cementite)and refining ferrites which distribute uniformly.Morphologies on tension fracture surface of optimized annealing material indicate that the numbers of dimple fracture show more finer toughness obviously comparing with other annealing materials.Moreover,the yield strength value of optimization annealing material decreases apparently by tensile test.Thus,the new optimized strategy is accurate and feasible.

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

    Science.gov (United States)

    Tomáš, Ivan; Kovářík, Ondřej; Kadlecová, Jana; Vértesy, Gábor

    2015-09-01

    Fatigue damage was investigated by the method of magnetic adaptive testing (MAT), which is based on the systematic measurement and evaluation of minor magnetic hysteresis loops. A large number of magnetic measurements were performed on a single reference series of low carbon steel flat samples, which were fatigued by cyclic bending in an identical way, up to an increasing level of fatigue damage. The measurements of the magnetic properties of these samples were repeated under varied conditions, including speed of magnetization of the samples, sample temperature during the measurement, choice of the evaluated signal, frequency of the voltage sampling, and range of the applied amplitudes of the magnetizing field/current. Special attention was turned to the influence of the thickness of the non-ferromagnetic spacers positioned between the surface of the samples and the flat fronts of the attached magnetizing yokes. On one hand, the spacers decrease the values of the induced signal and its derivatives, but on the other hand they substantially increase the reproducibility of the measurement and positively influence the shapes of the resulting degradation curves. Optimum conditions for the magnetic measurement of the fatigue damage were searched, found, and recommended. The results indicate the reliable applicability of MAT to detect early stages of the material fatigue, and to predict its residual lifetime.

  18. Inhibition of carbon steel corrosion by 11-aminoundecanoic acid

    Directory of Open Access Journals (Sweden)

    Saad Ghareba

    2015-12-01

    Full Text Available The current study reports results on the investigation of the possibility of using 11-aminoundecanoic acid (AA as an inhibitor of general corrosion of carbon steel (CS in HCl under a range of experimental conditions: inhibitor concentration, exposure time, electrolyte temperature and pH and CS surface roughness. It was found that AA acts as a mixed-type inhibitor, yielding maximum inhibition efficiency of 97 %. The adsorption of AA onto the CS surface was described by the Langmuir adsorption isotherm. The corresponding apparent Gibbs free energy of AA adsorption on CS at 295 K was calculated to be −30.2 kJ mol–1. The adsorption process was found to be driven by a positive change in entropy of the system. PM-IRRAS measurements revealed that the adsorbed AA layer is amorphous, which can be attributed to the repulsion between the neighboring positively charged amine groups and a high heterogeneity of the CS surface. It was also found that the AA provides very good corrosion protection of CS of various surface roughness, and over a prolonged time.

  19. Causes and prevention of corrosion in carbon steel natural gas coolers

    Energy Technology Data Exchange (ETDEWEB)

    Kotwica, D.J.; Minevski, L. [BetzDearborn, The Woodlands, TX (United States)

    1998-12-31

    Two case histories in which high pressure natural gas coolers had failed due to the presence of carbon dioxide are reviewed. CO{sub 2} along with CO and H{sub 2}S are acid gases usually present in natural gas feeds. Carbonic acid can form in aqueous condensate, lowering the pH and locally corroding mild steel tube metal. Stress corrosion cracking (SCC) can occur in tubing containing residual tensile stresses from welding or manufacturing. Bicarbonates and carbonates concentrated in condensate from CO{sub 2} and CO present in natural gas are required to produce SCC. Cathodic depolarizers such as oxygen in conjunction with the presence of carbonic acid will increase the corrosion rate of mild steel. Oxygen also increases the susceptibility of mild steel to carbonate SCC.

  20. AISI/DOE Technology Roadmap Program: Improved Surface Quality of Exposed Automotive Sheet Steels

    Energy Technology Data Exchange (ETDEWEB)

    John G. Speer; David K. Matlock; Noel Meyers; Young-Min Choi

    2002-10-10

    Surface quality of sheet steels is an important economic and technical issue for applications such as critical automotive surfaces. This project was therefore initiated to develop a more quantitative methodology for measuring surface imperfections, and to assess their response to forming and painting, particularly with respect to their visibility or invisibility after painting. The objectives were met, and included evaluation of a variety of imperfections present on commercial sheet surfaces or simulated using methods developed in the laboratory. The results are expected to have significant implications with respect to the methodology for assessing surface imperfections, development of quantitative criteria for surface inspection, and understanding and improving key painting process characteristics that influence the perceived quality of sheet steel surfaces.

  1. Evaluation of corrosion of steel embedded in concrete exposed to carbonation AAS using a factorial experiment with repeated measures. Evaluación de la corrosión del acero embebido en concreto AAS, expuesto a carbonatación mediante un experimento factorial con medidas repetidas.

    Directory of Open Access Journals (Sweden)

    W Aperador Chaparro

    2013-03-01

    Full Text Available This article presents various techniques for assessing corrosion, the linear polarization resistance and galvanostatic pulse, the analysis was performed using analysis of variance models using a factorial experiment with three factors, one repeated measure, because on the same experimental unit (reinforced concrete, it experienced several samples to be measured in time (0 h=1, 350 h=2, 700 h=3, 1050 h=4, 1700 h=5 y 2600 h=6. This makes the observations are not independent, the other two factors relate to, the binder (ce: 1 = activatedslag [AAS] and 2 = ordinary Portland concrete [OPC] and the exposure condition (ca: 1 = y 2 = environmental exposure accelerated carbonation. These factors were discussed according to the results of the electrochemical properties. Initially performed the statistical processing of each of the variables in relation to the properties and analyzed the interaction between them. Where they established the differences in materials used as coating steel, concrete, OPC and AAS. OPC concrete specimens, exhibited a resting potential, polarization resistance and ohmic (CO2 condition than those obtained for reinforced concrete in AAS.En este artículo se presentan las técnicas de evaluación de la corrosión, tales como potencial de corrosión, resistencia lineal a la polarización y pulso galvanostático a los concretos de activación alcalina (AAS y Portland tipo I (OPC. El estudio se realizó por medio de modelos de análisis de varianza, aplicando un experimento factorial con tres factores, uno de ellos medida repetida, debido a que sobre la misma unidad experimental (concreto armado AAS y OPC se ensayaron varias muestras para medirlas en el tiempo (0 h=1, 350 h=2, 700 h=3, 1050 h=4, 1700 h=5 y 2600 h=6, lo que hace que las observaciones no sean independientes; los otros dos factores corresponden al cementante (ce: 1=escoria activada alcalinamente [AAS] y 2=concreto Portland ordinario [OPC] y la condición de exposici

  2. Corrosion behavior of some transition metals and 4340 steel metals exposed to sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Natishan, P.M.; Jones-Meehan, J.; Loeb, G.I.; Little, B.J.; Ray, R.; Beard, M.

    1999-11-01

    Microbial colonization of metals (zirconium, chromium, niobium, tantalum, molybdenum, tungsten, and type 4340 steel [UNS G43400]) and susceptibility of these metals to microbiologically influenced corrosion by sulfate-reducing bacteria was investigated. Environmental scanning electron microscopy characterization after 12 months and 21 months showed patchy biofilms on all metals except tungsten. Weight loss after 24 months for zirconium and niobium were either nonexistent or negligible, indicating that these metals did not experience MIC under the test conditions.

  3. Dilatometric investigations of phase transformations at heating and cooling of hardened, unalloyed, high-carbon steels

    Directory of Open Access Journals (Sweden)

    J. Pacyna

    2011-05-01

    Full Text Available Purpose: The reason for writing this paper was to describe the kinetics of phase transformations during continuous heating from hardened state and subsequent cooling of unalloyed high carbon steel.Design/methodology/approach: Dilatometric investigations were performed using a DT 1000 dilatometer of a French company Adamel. Samples after quenching and quenching and sub-quenching in liquid nitrogen (-196 °C were heated up 700 °C at the rate of 0.05 °C/s and subsequent cooled to room temperature at the rate of 0.05 °C/s.Findings: Regardless of heating the hardened high-carbon steel to 700 °C, a small fraction of the retained austenite remained in its structure, and was changing into fresh martensite only during cooling in the temperature range: 280°C-170°C.Research limitations/implications: Schematic presentation of the differential curve of tempering of the hardened high-carbon, unalloyed steel illustrating the phase transformations occurring during heating from hardened state.Practical implications: An observation, that a small fraction of the retained austenite remained in the structure of tempered high-carbon steel, indicates that even unalloyed steel should be tempered two times.Originality/value: Detailed descriptions of kinetics phase transformations during heating from hardened state of unalloyed high carbon steel.

  4. The possibility of tribopair lifetime extending by welding of quenched and tempered stainless steel with quenched and tempered carbon steel

    Directory of Open Access Journals (Sweden)

    V. Marušić

    2015-04-01

    Full Text Available In the conditions of tribocorrosion wear, extending of parts lifetime could be achieved by using stainless steel,which is hardened to sufficiently high hardness. In the tribosystem bolt/ bushing shell/link plate of the bucket elevator transporter conveyor machine, the previously quenched and tempered martensitic stainless steel for bolts is hardened at ≈47 HRC and welded with the quenched and tempered high yield carbon steel for bolts. Additional material, based on Cr-Ni-Mo (18/8/6 is used. The microstructure and hardness of welded samples are tested. On the tensile tester, resistance of the welded joint is tested with a simulated experiment. Dimensional control of worn tribosystem elements was performed after six months of service.

  5. 77 FR 43806 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of...

    Science.gov (United States)

    2012-07-26

    ... International Trade Administration Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the... Department) initiated an administrative review of the antidumping duty order on seamless carbon and alloy... carbon and alloy steel standard, line, and pressure pipe from the People's Republic of China covering...

  6. 77 FR 44213 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea...

    Science.gov (United States)

    2012-07-27

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... certain corrosion-resistant carbon steel flat products (``CORE'') from Germany and the Republic of Korea..., Director, Office 3, on ``Sunset Reviews of the Antidumping Duty Orders on Corrosion-Resistant Carbon...

  7. The effect of metal microstructure on the initial attachment of Escherichia coli to 1010 carbon steel.

    Science.gov (United States)

    Javed, M A; Stoddart, P R; McArthur, S L; Wade, S A

    2013-09-01

    Metallurgical features have been shown to play an important role in the attachment of microorganisms to metal surfaces. In the present study, the influence of the microstructure of as-received (AR) and heat-treated (HT) 1010 carbon steel on the initial attachment of bacteria was investigated. Heat treatment was carried out with the aim of increasing the grain size of the carbon steel coupons. Mirror-polished carbon steel coupons were immersed in a minimal medium inoculated with Escherichia coli (ATCC 25922) to investigate the early (15, 30 and 60 min) and relatively longer-term (4 h) stages of bacterial attachment. The results showed preferential colonisation of bacteria on the grain boundaries of the steel coupons. The bacterial attachment to AR steel coupons was relatively uniform compared to the HT steel coupons where an increased number of localised aggregates of bacteria were found. Quantitative analysis showed that the ratio of the total number of isolated (i.e., single) bacteria to the number of bacteria in aggregates was significantly higher on the AR coupons than the HT coupons. Longer-term immersion studies showed production of extracellular polymeric substances by the bacteria and corrosion at the grain boundaries on both types of steel coupon tested.

  8. 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.

  9. Stress and Composition of Carbon Stabilized Expanded Austenite on Stainless Steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2009-01-01

    Low-temperature gaseous carburizing of stainless steel is associated with a colossal supersaturation of the fcc lattice with carbon, without the development of carbides. This article addresses the simultaneous determination of stress and composition profiles in layers of carbon xpanded austenite...

  10. Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength low carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in low carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have ob- vious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

  11. Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

    Institute of Scientific and Technical Information of China (English)

    FU Jie; WU HuaJie; LIU YangChun; KANG YongLin

    2007-01-01

    This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength Iow carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in Iow carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have obvious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

  12. Biocidal effect of cathodic protection on bacterial viability in biofilm attached to carbon steel.

    Science.gov (United States)

    Miyanaga, Kazuhiko; Terashi, Ryosuke; Kawai, Hirofumi; Unno, Hajime; Tanji, Yasunori

    2007-07-01

    Biofilm formed on carbon steel by various species of bacterial cells causes serious problems such as corrosion of steel, choking of flow in the pipe, deterioration of the heat-transfer efficiency, and so on. Cathodic protection is known to be a reliable method for protecting carbon steel from corrosion. However, the initial attachment of bacteria to the surface and the effects of cathodic protection on bacterial viability in the biofilm have not been clarified. In this study, cathodic protection was applied to an artificial biofilm containing Pseudomonas aeruginosa (PAO1), a biofilm constituent, on carbon steel. The aims of this study were to evaluate the inhibition effect of cathodic protection on biofilm formation and to reveal the inhibition mechanisms. The viability of PAO1 in artificial biofilm of 5 mm thickness on cathodically protected steel decreased to 1% of the initial cell concentration. Analysis of pH distribution in the artificial biofilm by pH microelectrode revealed that pH in proximity to carbon steel increased to approximately 11 after cathodic protection for 5 h. Moreover, 99% of region in the artificial biofilm was under the pH conditions of over nine. A simulation of pH profile was shown to correspond to experimental values. These results indicate cells in the artificial biofilm were killed or damaged by cathodic protection due to pH increase.

  13. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    BOOMER, K.D.

    2007-08-21

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed.

  14. Effect of carbon dioxide and temperature on passive film parametersof superduplex stainless steel

    Directory of Open Access Journals (Sweden)

    Emandro Vieira da Costa

    2013-01-01

    Full Text Available Superduplex stainless steel has been frequently employed in new sites of Brazilian Pre-Salt. In these environments, chloride concentration, temperature and carbon dioxide are normally present in higher levels than those at sea water at room temperature. In these conditions, it is expected that the passive films of stainless steel also show modifications. To better understand such modifications, samples of superduplex stainless steel UNS S32750 were submitted to electrochemical impedance measurements in brine media, at two temperatures and under presence/absence of carbon dioxide. The electrochemical impedance results were initially tested using the Kramers-Kronig transform and subsequently fitted by equivalent circuit employing constant phase elements - CPE. Moreover, to quantify the effect of each factor (temperature, chloride, carbon dioxide and microstructure on the equivalent circuit, their parameters were tested applying statistical analysis. Significant effect of carbon dioxide and temperature was found on related parameters of passive film for heat-treated samples.

  15. Can Thermally Sprayed Aluminum (TSA) Mitigate Corrosion of Carbon Steel in Carbon Capture and Storage (CCS) Environments?

    Science.gov (United States)

    Paul, S.; Syrek-Gerstenkorn, B.

    2017-01-01

    Transport of CO2 for carbon capture and storage (CCS) uses low-cost carbon steel pipelines owing to their negligible corrosion rates in dry CO2. However, in the presence of liquid water, CO2 forms corrosive carbonic acid. In order to mitigate wet CO2 corrosion, use of expensive corrosion-resistant alloys is recommended; however, the increased cost makes such selection economically unfeasible; hence, new corrosion mitigation methods are sought. One such method is the use of thermally sprayed aluminum (TSA), which has been used to mitigate corrosion of carbon steel in seawater, but there are concerns regarding its suitability in CO2-containing solutions. A 30-day test was carried out during which carbon steel specimens arc-sprayed with aluminum were immersed in deionized water at ambient temperature bubbled with 0.1 MPa CO2. The acidity (pH) and potential were continuously monitored, and the amount of dissolved Al3+ ions was measured after completion of the test. Some dissolution of TSA occurred in the test solution leading to nominal loss in coating thickness. Potential measurements revealed that polarity reversal occurs during the initial stages of exposure which could lead to preferential dissolution of carbon steel in the case of coating damage. Thus, one needs to be careful while using TSA in CCS environments.

  16. Influence of shadow effect on the strength of steel beams exposed to fire

    DEFF Research Database (Denmark)

    Virdi, Kuldeep; Wickström, Ulf

    2013-01-01

    in or in direct contact with concrete are not considered appropriately - only the reduction of the exposed area is taken into account. In addition, the shadow effect is rarely considered in structures with both concrete and asteel elements such as composite floors. It has been mainly used for stand-alone columns...

  17. Microstructure Examinations in Corners of the Low-Carbon Steel Slabs from Continuos Caster Machine

    Directory of Open Access Journals (Sweden)

    Kwinta G.

    2016-12-01

    Full Text Available The exposed selvedge layers in slabs cast by the continuous process should be free from surface defects, which in most cases appear in the form of cracks on the casting surface and run to its interior. In addition to the parameters of the casting process, the occurrence of such defects depends on the chemical composition of cast steel, on the segregation of surface active elements and formation of the precipitates of carbides, nitrides and other phases. Due to the frequent occurrence of defects in corners of the slabs, non-destructive testing was performed on the mechanically cleaned surfaces of slabs. The test material was low-carbon API(American Petroleum Institute API 5L standard steel micro alloyed with Nb and Ti designed for the production of pipes to handle gas, oil and other liquid and gaseous fuels. Despite the use of different methods of inspection, i.e. ultrasonic, magnetic particle and penetrant, cracks were not traced in the examined material. Then, from the corners of the examined slabs, specimens were cut out for metallographic examinations. The main purpose of these examinations was to disclose the presence of possible cracks and micro cracks on the surfaces transversal and longitudinal to the direction of casting. At the same time, studies were conducted to establish the number and morphology of non-metallic inclusions in selvedge layers of the slab corners and axis. Additionally, hardness of the slabs was measured. The conducted studies revealed only some minor differences in the slab hardness along its axis (130 ÷ 135 HB and in selvedge layers (120 ÷ 123 HB.

  18. Effect of thermal treatment on the corrosion resistance of Type 316L stainless steel exposed in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Y. [Department of Materials Science & Engineering, McMaster University, Hamilton, ON (Canada); Zheng, W. [CanmetMATERIALS, Natural Resources Canada, Hamilton, ON (Canada); Guzonas, D.A. [Canadian Nuclear Laboratories Chalk River Laboratories, ON (Canada); Cook, W.G. [Department of Chemical Engineering, University of New Brunswick, Fredericton, NB (Canada); Kish, J.R., E-mail: kishjr@mcmaster.ca [Department of Materials Science & Engineering, McMaster University, Hamilton, ON (Canada)

    2015-09-15

    There are still unknown aspects about the growth mechanism of oxide scales formed on candidate stainless steel fuel cladding materials during exposure in supercritical water (SCW) under the conditions relevant to the Canadian supercritical water-cooled reactor (SCWR). The tendency for intermetallic precipitates to form within the grains and on grain boundaries during prolonged exposure at high temperatures represents an unknown factor to corrosion resistance, since they tend to bind alloyed Cr. The objective of this study was to better understand the extent to which intermetallic precipitates affects the mode and extent of corrosion in SCW. Type 316L stainless steel, used as a model Fe–Cr–Ni–Mo alloy, was exposed to 25 MPa SCW at 550 °C for 500 h in a static autoclave for this purpose. Mechanically-abraded samples were tested in the mill-annealed (MA) and a thermally-treated (TT) condition. The thermal treatment was conducted at 815 °C for 1000 h to precipitate the carbide (M{sub 23}C{sub 6}), chi (χ), laves (η) and sigma (σ) phases. It was found that although relatively large intermetallic precipitates formed at the scale/alloy interface locally affected the oxide scale formation, their discontinuous formation did not affect the short-term overall apparent corrosion resistance.

  19. Study of the corrosion behaviors of 304 austenite stainless steel specimens exposed to static liquid lithium at 600 K

    Science.gov (United States)

    Meng, Xiancai; Zuo, Guizhong; Ren, Jun; Xu, Wei; Sun, Zhen; Huang, Ming; Hu, Wangyu; Hu, Jiansheng; Deng, Huiqiu

    2016-11-01

    Investigation of corrosion behavior of stainless steel served as one kind of structure materials exposed to liquid lithium (Li) is one of the keys to apply liquid Li as potential plasma facing materials (PFM) or blanket coolant in the fusion device. Corrosion experiments of 304 austenite stainless steel (304 SS) were carried out in static liquid Li at 600 K and up to1584 h at high vacuum with pressure less than 4 × 10-4 Pa. After exposure to liquid Li, it was found that the weight of 304 SS slightly decreased with weight loss rate of 5.7 × 10-4 g/m2/h and surface hardness increased by about 50 HV. Lots of spinel-like grains and holes were observed on the surface of specimens measured by SEM. By further EDS, XRD and metallographic analyzing, it was confirmed that the main compositions of spinel-like grains were M23C6 carbides, and 304 SS produced a non-uniform corrosion behavior by preferential grain boundary attack, possibly due to the easy formation of M23C6 carbides and/or formation of Li compound at grain boundaries.

  20. Modeling of mechanical behaviour of HSLA low carbon bainitic steel thermomechanically processed

    Science.gov (United States)

    Santos, D. B.; Rodrigues, P. C. M.; Cota, A. B.

    2003-10-01

    A comparative study of the microstructure characterization and mechanical properties was done in a HSLA low carbon (0.08%) bainitic steel containing boron, developed by industry as a bainitic steel grade APIX80. The steel was submitted to two different thermomechanical processes. In the first one, controlled rolling followed by accelerated cooling was applied in laboratory mill. In the second processing, specimens of the same steel were submitted to hot torsion testing. The influence of cooling conditions like start cooling temperature, cooling rates and finish cooling temperature on the microstructure and mechanical properties were investigated. The final microstructure obtained was a complex mixture of polygonal ferrite, perlite, bainite and martensite/retained austenite constituent. The use of multiple regression analysis allowed the establishment of quantitative relationships between the accelerated cooling variables and mechanical properties of the steel available from Vickers microhardness and tensile tests.

  1. The impact properties of laminated composites containing ultrahigh carbon (UHC) steels

    Science.gov (United States)

    Kum, D. W.; Oyama, T.; Wadsworth, J.; Sherby, O. D.

    AN ULTRAHIGH carbon (UHC) steel/mild steel laminated composite and a UHC steel/UHC steel laminate have been successfully manufactured by a roll-bonding procedure. Impact properties of these laminates, as well as of monolithic samples of the steels contained in these laminates, have been determined in the crackarrestor orientation over the temperature range 25 to -196°C. Both notched and unnotched samples of the laminated composite and laminate have been tested. Extremely low ductile-to-brittle temperatures of -140°C, and very high shelf energies (>325 J), have been found both for the laminated composites and the laminates. This remarkably good behavior is shown to be a result of notch blunting by delamination within the laminates.

  2. Corrosion of carbon steel, zinc and copper by air pollution in Chongqing

    Institute of Scientific and Technical Information of China (English)

    YE Di; ZHAO Da-wei; CHEN Gang-cai; ZHANG Dong-bao

    2007-01-01

    This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H+, were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose-response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.

  3. Corrosion of stainless and carbon steels in molten mixtures of industrial nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Goods, S.H.; Bradshaw, R.W. [Sandia National Labs., Livermore, CA (United States); Prairie, M.R.; Chavez, J.M. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    Corrosion behavior of two stainless steels and carbon steel in mixtures of NaNO{sub 3} and KNO{sub 3} was evaluated to determine if impurities found in commodity grades of alkali nitrates aggravate corrosivity as applicable to an advanced solar thermal energy system. Corrosion tests were conducted for 7000 hours with Types 304 and 316 stainless steels at 570C and A36 carbon steel at 316C in seven mixtures of NaNO{sub 3} and KNO{sub 3} containing variations in impurity concentrations. Corrosion tests were also conducted in a ternary mixture of NaNO{sub 3}, KNO{sub 3}, and Ca(NO{sub 3}){sub 2}. Corrosion rates were determined by descaled weight losses while oxidation products were examined by scanning electron microscopy, electron microprobe analysis, and X-ray diffraction. The nitrate mixtures were periodically analyzed for changes in impurity concentrations and for soluble corrosion products.

  4. Mathematical modeling and validation of the carburizing of low carbon steels

    Science.gov (United States)

    García Mariaca, A.; Cendales, E. D.; Chamarraví, O.

    2016-02-01

    This paper shows the mathematical modeling of heat and mass transfer in transient state of cylindrical bars of low carbon steel subjected to carburizing process. The model solution for the two phenomena was performed using a one-dimensional analysis in the radius direction, using the numerical method of finite differences; also a sensitivity analysis by varying the coefficient of convective heat transfer (h) is performed. The modeling results show that this carburization steel is strongly dependent on h. These results suggest that if it can increase the value of h in this kind of process could reduce the time of process for this heat treatment. Additionally, an experimental procedure was established by carburization of a steel AISI SAE 1010, which develops cementing solid phase and the specimen steel and micrographic hardness profiles obtained from samples of the specimen analysis was performed, to determine the penetration depth of the carbon and validate this result over the values obtained by the computer model.

  5. Corrosion of Carbon Steel under Epoxy-varnish Coating Studied by Scanning Kelvin Probe

    Institute of Scientific and Technical Information of China (English)

    XIAO Kui; DONG Chaofang; ZHANG Xin; WU Junsheng; XU Longjiao; LI Xiaogang

    2012-01-01

    The corrosion behavior of partly coated carbon steel was investigated by salt spray test and scanning Kelvin probe (SKP) in order to understand the long-term corrosion behavior of coated carbon steel in marine atmosphere environment.The localized corrosion was accurately characterized by SKP in both coated and uncoated regions.The SKP results showed that Volta potential varied with the test time,and the more the corrosion products,the more positive the potential.The borderline between coated and uncoated regions of partly coated steel shifted towards the coated side with the increasing of test time.The coating disbonding rate could be determined according to the shift of potential borderline measured by SKP.The corrosion mechanism of partly coated steel in NaC1 salt spray was discussed according to the potential maps and corrosion morphologies.

  6. Application of standard end-quench test to structural steel with elevated carbon content at low hardenability

    Science.gov (United States)

    Gliner, R. E.; Vybornov, V. V.

    2013-03-01

    Special features of the test of plain steel with elevated carbon content for hardenability, which is used in the production of gears instead carburizing alloy steel, are considered. It is shown that it is possible and effective to use computer simulation of the hardenability detectable by testing of this class of steel by the method of end quenching with allowance for the chemical composition.

  7. 78 FR 60850 - Carbon and Certain Alloy Steel Wire Rod From Brazil: Final Results of the Expedited Second Sunset...

    Science.gov (United States)

    2013-10-02

    ... International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Brazil: Final Results of the... certain alloy steel wire rod (wire rod) from Brazil would be likely to lead to continuation or recurrence... Alloy Steel Wire Rod from Brazil, 67 FR 55805 (August 30, 2002). \\2\\ See Initiation of...

  8. 76 FR 2344 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Preliminary Results of...

    Science.gov (United States)

    2011-01-13

    ... stabilized (commonly referred to as interstitial-free (``IF'')) steels, high-strength low-alloy (``HSLA... columbium), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels...: vacuum-degassed fully stabilized; high-strength low-alloy; and the substrate for motor lamination...

  9. Aluminizing and subsequent nitriding of plain carbon low alloy steels for piston ring applications

    Energy Technology Data Exchange (ETDEWEB)

    Bindumadhavan, P.N.; Keng Wah, H.; Prabhakar, O. [Nanyang Technol. Univ., Singapore (Singapore). Div. of Mater. Eng.; Makesh, S. [Chemical and Nuclear Engineering Building, University of Maryland, 20783, College Park, MD (United States); Gowrishankar, N. [I P Rings Ltd., D 11/12, Industrial Estate, 603209, Maraimalainagar (India)

    2000-05-22

    Nitriding is a case hardening process that is commonly used for increasing the wear life of automotive piston rings. However, special alloy steels are required to achieve high surface hardness and nitrided case depth values required by the automotive industry. The cost of such alloy steels is one of the major components of the total cost of the nitrided piston ring. To address this issue, efforts have been directed towards development of cheaper raw materials as substitutes for nitridable steels. In this study, an attempt has been made to increase the surface hardness of two plain carbon low alloy steels by aluminizing and subsequent diffusion treatment and nitriding. The process parameters for the aluminizing operation are discussed. Results indicate that a near twofold increase in surface hardness is achievable by aluminizing followed by diffusion treatment and nitriding (580-1208 HV for EN32B steel and 650-1454 HV for 15CR3 steel). It has also been found that the nitrided case depth obtained (0.11-0.13 mm for EN32B steel and 0.10-0.14 mm for 15CR3 steel) matches well with the general requirements of the piston ring industry. The diffusion of aluminum into the alloy layer has also been discussed and the theoretical predictions were compared with actual values of Al concentration, as obtained by SEM-EDS system. It is found that Fick's law gives a fairly good prediction of the actual Al concentration profile, in spite of the complexity of the diffusion path. X-Ray diffraction studies have confirmed the presence of AlN in the alloy layer, which could be instrumental in the significant increase in surface hardness. It is proposed that aluminizing followed by diffusion treatment and nitriding of plain carbon low alloy steels could provide an alternative to the use of expensive nitridable steels for piston ring applications. (orig.)

  10. EFFECT OF CARBON CONTENT ON MICROSTRUCTURE AND PROPERTIES OF HIGH STRENGTH AND HIGH ELONGATION STEELS

    Institute of Scientific and Technical Information of China (English)

    Y. Chen; X. Chen; P.H. Li; S.K. Pu; Z.X. Yuan; B.F. Xu; D.X. Lou; A.M. Guo; S.B.Zhou

    2003-01-01

    The microstructure and mechanical properties of new kind of hot-rolled high strengthand high elongation steels with retained austenite were studied by discussing the in-fluence of different carbon content. The research results indicate that carbon contenthas a significant effect on retaining austenite and consequently resulting in high elon-gation. Besides, new findings about relationship between carbon content and retainedaustenite as well as properties were discussed in the paper.

  11. EFFECT OF CARBON CONTENT ON MICROSTRUCTURE AND PROPERTIES OF HIGH STRENGTH AND HIGH ELONGATION STEELS

    Institute of Scientific and Technical Information of China (English)

    Y.Chen; X.Chen; 等

    2003-01-01

    The microstructure and mechanical properties of new kind of hot-rolled high strength and high elongation steels with retained austenite were studied by discussing the in-fluence of different carbon content.The research results indicate that carbon content has a significant effect on retaining austenite and consequently resulting in high elon-gation.Besides,new findings about relationship between carbon content and retained austenite as well as properties were discussed in the paper.

  12. Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

    OpenAIRE

    Hu, J; Koleva, D. A.; Wit, J.H.W. de; Kolev, H.; Breugel, K. van

    2011-01-01

    This study presents the results on the investigation of the corrosion behavior of carbon steel in model alkaline medium in the presence of very low concentration of polymeric nanoaggregates [0.0024 wt % polyethylene oxide (PEO)113-b-PS70 micelles]. The steel electrodes were investigated in chloride free and chloride-containing cement extracts. The electrochemical measurements (electrochemical impedance spectroscopy and potentiodynamic polarization) indicate that the presence of micelles alter...

  13. Corrosion Performance of Carbon Steel in Micelle-containing Cement Extract

    OpenAIRE

    Hu, J; Koleva, D. A.; Wit, J.H.W. de; Petrov, P; Breugel, K. van

    2010-01-01

    This study presents the results from a preliminary investigation on the corrosion behavior of low carbon steel in cement extract (CE) in the presence of very low concentration polymeric nanoaggregates (PEO113-b-PS70 micelles). The steel electrodes were investigated in Cl--containing CE as corrosion medium, compared to chloride-free CE as a reference case. The results from the electrochemical measurements (Electrochemical Impedance Spectroscopy (EIS) and Potentio-dynamic Polarization (PDP)) in...

  14. Enhanced wear and corrosion resistance of plasma electrolytic carburized layer on T8 carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jie; Wang, Bin; Zhang, Yifan; 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); Xia, Yuan; Li, Guang [Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (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)

    2016-03-01

    A hardening layer of 70 μm on T8 carbon steel was fabricated by plasma electrolytic carburizing (PEC) in glycerol solution at 380 V with 3 min treatment. The discharge process was characterized using optical emission spectroscopy (OES), and the electron temperature in plasma envelope was determined. Meanwhile, diffusion coefficient of carbon was calculated on the basis of carbon concentration profile. The tribological property of carburized steel under dry sliding against ZrO{sub 2} ball was measured by a ball-disc friction and wear tester. The corrosion behaviors were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the carburized layer mainly contained α-Fe and Fe{sub 3}C phases with maximum hardness of 620 HV. The PEC treatment significantly decreased the friction coefficient from 0.4 to 0.1. The wear rate of PEC treated steel was about 5.86 × 10{sup −6} mm{sup 3}/N·m, which was less than 1/4 of T8 steel substrate. After PEC treatment, the wear and corrosion resistance of T8 steel were improved. Particularly, the pitting corrosion of steel substrate was obviously suppressed. - Highlights: • Electron temperature in plasma electrolytic carburizing process is determined. • Diffusion coefficient of carbon in PEC is higher than conventional carburizing. • Wear and corrosion resistance of T8 steel are both improved after PEC treatment. • Pitting corrosion of steel substrate is obviously suppressed by PEC treatment.

  15. Aminopyrimidine derivatives as inhibitors for corrosion of 1018 carbon steel in nitric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, M. [Chemistry Department, Faculty of Science, Benha University, Benha (Egypt)]. E-mail: metwally552@hotmail.com; Helal, E.A. [Corrosion Department, Badr El-Din Petroleum company (Egypt); Fouda, A.S. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt)]. E-mail: asfouda@yahoo.com

    2006-07-15

    The effect of some aminopyrimidine derivatives on the corrosion of 1018 carbon steel in 0.05 M HNO{sub 3} solution was studied using weight loss and polarization techniques. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitor and with decreasing temperature. The addition of KI to aminopyrimidine derivatives enhanced the inhibition efficiency due to synergistic effect. The inhibitors are adsorbed on the steel surface according to Temkin isotherm. Some thermodynamic functions were computed and discussed. It was found that the aminopyrimidine derivatives provide a good protection to steel against pitting corrosion in chloride containing solutions.

  16. Corrosion and Runoff Behavior of Carbon Steel in Simulated Acid Rain

    Institute of Scientific and Technical Information of China (English)

    Baigang AN; Xueyuan ZHANG; Enhou HAN; Honxi LI

    2004-01-01

    Under the condition of simulated rain precipitation in the laboratory, with ElS and SEM observation, the effects of pH value of simulated rain on corrosion and runoff behavior of carbon steel A3 were studied. The corrosion rate of A3 steel increased and runoff action of rain precipitation on A3 steel surface was intensified with decreasing pH value, of simulated rainwater.The runoff and corrosion traces were formed along the flowing direction of rainwater, which appeared more apparently with decreasing pH value.

  17. A Transmission Electron Microscopy Study of Plate Martensite Formation in High-carbon Low Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    Albin Stormvinter; Peter Hedstr(o)m; Annika Borgenstam

    2013-01-01

    The martensitic microstructures in two high-carbon low alloy steels have been investigated by classical and automated crystallographic analysis under a transmission electron microscope.It is found that the martensitic substructure changes from consisting mostly of transformation twins for 1.20 mass% carbon (C) steel to both transformation twins and planar defects on {101}M for 1.67 mass% C steel.In the 1.67 mass% C steel it is further found that small martensite units have a rather homogeneous substructure,while large martensite units are more inhomogeneous.In addition,the martensite units in both steels are frequently found to be of zigzag patterns and have distinct crystallographic relationships with neighboring martensite units,e.g.kink or wedge couplings.Based on the present findings the development of martensite in high-carbon low alloy steels is discussed and a schematic of the martensite formation is presented.Moreover,whether the schematic view can be applied to plate martensite formation in general,is discussed.

  18. 75 FR 75455 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of Full...

    Science.gov (United States)

    2010-12-03

    ... (``IF'')) steels, high strength low alloy (``HSLA'') steels, and the substrate for motor lamination... titanium and/or niobium added to stabilize carbon and nitrogen elements. HSLA steels are recognized as... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From...

  19. Effect of Intercritical Heat Treatment on the Abrasive Wear Behaviour of Plain Carbon Dual Phase Steel

    Science.gov (United States)

    Manoj, M. K.; Pancholi, V.; Nath, S. K.

    Dual phase (DP) steels have been prepared from low carbon steel (0.14% C) at intercritical temperature 740°C and time is varied from 1 minute to 30 minutes followed by water quenching. These steels have been characterized by optical microscopy, FE-SEM, hardness measurements, tensile properties and electron backscattered diffraction (EBSD) studies. Tensile properties of a typical dual phase steel are found to be 805 MPa ultimate tensile strength with 18% total elongation. Martensite volume fraction of D P steel (determined by EBSD technique) prepared at 740°C for 6 minutes is found to be 10.2% and the grain size of ferrite and martensite found to be 14.39 micron and 1.05 microns respectively. Abrasive wear resistance of dual phase steels has been determined by pin on drum wear testing machine. DP steels have been found to be 25% more wear resistant than that of normalized steel. Short intercritical heating time followed by water quenching gives higher wear resistance by virtue of smaller and well dispersed martensite island in the matrix of ferrite.

  20. Mechanical and service properties of low carbon steels processed by severe plastic deformation

    Directory of Open Access Journals (Sweden)

    J. Zrnik

    2009-07-01

    Full Text Available The structure and properties of the 0,09% C-Mn-Si-Nb-V-Ti, 0,1% C-Mn-V-Ti and 0,09% C-Mo-V-Nb low-carbon steels were studied after cold equal-channel angular pressing (ECAP. ECAP leads to the formation of partially submicrocrystalline structure with a grain size of 150 – 300 nm. The submicrocrystalline 0,09% C-Mn-Si-Nb-V-Ti steel compared with the normalized steel is characterized by Re higher more than by a factor of 2 and by the impact toughness higher by a factor of 3,5 at a test temperature of -40°C. The plasticity in this case is somewhat lower. The high-strength state of the submicrocrystalline 0,1% C-Mn-V-Ti and 0,09% C-Mo-V-Nb steels after ECAP is retained up to a test temperature of 500°C. The strength properties at 600°C (i.e. the fire resistance of these steels are higher by 20-25% as compared to those of the undeformed steels. The strength of the 0,09% C-Mo-V-Nb steel at 600°C is substantially higher than that of the 0,1% C-Mn-V-Ti steel.

  1. Preparation and Characterization of Nano-Structured SiO2 Thin Films on Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Dong Zhou YAN; Gang WEI

    2003-01-01

    Nano-structured SiO2 thin films were prepared on the surface of carbon steel for the first time by LPD. The compositions of the films were analyzed by XPS, and the surface morphology of the thin films were observed by AFM. The thin films were constituted by compact particles of SiO2, and there was no Fe in the films. In the process of film forming, the SiO2 colloid particles were deposited or absorbed directly onto the surface of carbon steel substrates that were activated by acid solution containing inhibitor, and corrosion of the substrates was avoided. The nano-structured SiO2 thin films that were prepared had excellent protective efficiency to the carbon steel.

  2. Mechanics property Study for Interface Bim Composite of Zinc Alloy ZAS35/Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    陈基勇; 耿浩然; 杨爱玲

    2002-01-01

    The distortional fields of interface-U-field and V-field-have been obtained after the mechanics property for the geometric distortion of interface of cracked zinc alloy ZAS35/carbon steel is analyzed by means of a laser moire interferometry. The optimum cast preheating temperature has been decided in the light of the experiment of shear strength. After the microstructure of interface of bimetal composite of zinc alloy ZAS35/carbon steel is analyzed and studied with a X ray diffraction and an electronic scanning mirror (ESM), the phase component of metallurgical bond of interface of zinc alloy ZAS35/carbon steel has been gained, and the results of interface scan of distribution of elements Fe/Zn have been obtained with the dip coating temperature of 700(C. The above working theory, the experimental technology and its results will be introduced in this paper, and its results will be analyzed.

  3. Anodic Oxidation of Carbon Steel at High Current Densities and Investigation of Its Corrosion Behavior

    Science.gov (United States)

    Fattah-Alhosseini, Arash; Khan, Hamid Yazdani

    2017-02-01

    This work aims at studying the influence of high current densities on the anodization of carbon steel. Anodic protective coatings were prepared on carbon steel at current densities of 100, 125, and 150 A/dm2 followed by a final heat treatment. Coatings microstructures and morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the uncoated carbon steel substrate and the anodic coatings were evaluated in 3.5 wt pct NaCl solution through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The results showed that the anodic oxide coatings which were prepared at higher current densities had thicker coatings as a result of a higher anodic forming voltage. Therefore, the anodized coatings showed better anti-corrosion properties compared to those obtained at lower current densities and the base metal.

  4. Corrosion-resistant Foamed Cements for Carbon Steels

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Gill, S.; Pyatina, T., Muraca, A.; Keese, R.; Khan, A.; Bour, D.

    2012-12-01

    The cementitious material consisting of Secar #80, Class F fly ash, and sodium silicate designed as an alternative thermal-shock resistant cement for the Enhanced Geothermal System (EGS) wells was treated with cocamidopropyl dimethylamine oxide-based compound as foaming agent (FA) to prepare numerous air bubble-dispersed low density cement slurries of and #61603;1.3 g/cm3. Then, the foamed slurry was modified with acrylic emulsion (AE) as corrosion inhibitor. We detailed the positive effects of the acrylic polymer (AP) in this emulsion on the five different properties of the foamed cement: 1) The hydrothermal stability of the AP in 200 and #61616;C-autoclaved cements; 2) the hydrolysis-hydration reactions of the slurry at 85 and #61616;C; 3) the composition of crystalline phases assembled and the microstructure developed in autoclaved cements; 4) the mechanical behaviors of the autoclaved cements; and, 5) the corrosion mitigation of carbon steel (CS) by the polymer. For the first property, the hydrothermal-catalyzed acid-base interactions between the AP and cement resulted in Ca-or Na-complexed carboxylate derivatives, which led to the improvement of thermal stability of the AP. This interaction also stimulated the cement hydration reactions, enhancing the total heat evolved during cement’s curing. Addition of AP did not alter any of the crystalline phase compositions responsible for the strength of the cement. Furthermore, the AP-modified cement developed the porous microstructure with numerous defect-free cavities of disconnected voids. These effects together contributed to the improvement of compressive-strength and –toughness of the cured cement. AP modification of the cement also offered an improved protection of CS against brine-caused corrosion. There were three major factors governing the corrosion protection: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS

  5. Computational analysis of linear friction welding process and micromechanical modeling of deformation behavior for medium carbon steel

    Institute of Scientific and Technical Information of China (English)

    杨夏炜; 李文亚; 马铁军

    2015-01-01

    Finite element simulation of linear friction welding (LFW) medium carbon steel was carried out using the ABAQUS software. A two-dimensional (2D) coupled thermo-mechanical model was established. First, the temperature fields of medium carbon steel during LFW process were investigated. And then, the Mises stress and the 1st, 2nd and 3rd principal stresses fields’ evolution of the steel during LFW process were studied. The deformation behavior of LFW carbon steel was analyzed by using micromechanics model based on ABAQUS with Python code. The Lode parameter was expressed using the Mohr stress circle and it was investigated in detail.

  6. Multiaxial ratcheting of 20 carbon steel: Macroscopic experiments and microscopic observations

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yawei [State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Kang, Guozheng, E-mail: guozhengkang@yahoo.com.cn [State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Liu, Yujie; Jiang, Han [School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2013-09-15

    The multiaxial ratcheting behaviors of polycrystalline 20 ordinary carbon steel were investigated at room temperature. The macroscopic experimental results showed that the studied multiaxial ratcheting depends greatly on the mean stress, stress amplitude and loading path. The axial ratcheting strain increased with the increase of applied mean stress and stress amplitude. Apparent additional hardening was observed in the non-proportionally multiaxial cyclic loading. The multiaxial ratcheting of 20 carbon steel was lower than the corresponding uniaxial one and varies with different loading paths. Dislocation patterns and their evolutions of the multiaxial ratcheting of different loading paths were then investigated using transmission electron microscopy. The obtained images showed that, with the increasing number of loading cycles, the dislocation patterns evolved from dislocation lines and networks to dislocation tangles, walls and cells. After certain cycles, sub-grains were formed because of the re-arrangement of dislocations in the walls of cells and inside the cells since the cross slip of dislocations can be easily activated for the 20 carbon steel, a kind of body-centered cubic metal. The dislocation evolution of the multiaxial ratcheting is much quicker than that of the uniaxial one. With the reference to the uniaxial one of 20 carbon steel, the macroscopic multiaxial ratcheting behaviors can be qualitatively correlated with the microscopic observation of the dislocation patterns and their evolution. - Highlights: • Multiaxial loading hardly changes the cyclic stable feature of 20 carbon steel. • Multiaxial ratcheting of 20 carbon steel depends greatly on the load path. • Dislocation patterns evolve quicker in the multiaxial case. • The stabilized dislocation pattern is sub-grain, rather than the dislocation cell. • Sub-grains formed after certain cycles make the stable ratcheting strain rate large.

  7. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    OpenAIRE

    Weimin Song; Jian Yin

    2016-01-01

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%,...

  8. Direct gas-solid carbonation kinetics of steel slag and the contribution to in situ sequestration of flue gas CO(2) in steel-making plants.

    Science.gov (United States)

    Tian, Sicong; Jiang, Jianguo; Chen, Xuejing; Yan, Feng; Li, Kaimin

    2013-12-01

    Direct gas-solid carbonation of steel slag under various operational conditions was investigated to determine the sequestration of the flue gas CO2 . X-ray diffraction analysis of steel slag revealed the existence of portlandite, which provided a maximum theoretical CO2 sequestration potential of 159.4 kg CO 2 tslag (-1) as calculated by the reference intensity ratio method. The carbonation reaction occurred through a fast kinetically controlled stage with an activation energy of 21.29 kJ mol(-1) , followed by 10(3) orders of magnitude slower diffusion-controlled stage with an activation energy of 49.54 kJ mol(-1) , which could be represented by a first-order reaction kinetic equation and the Ginstling equation, respectively. Temperature, CO2 concentration, and the presence of SO2 impacted on the carbonation conversion of steel slag through their direct and definite influence on the rate constants. Temperature was the most important factor influencing the direct gas-solid carbonation of steel slag in terms of both the carbonation conversion and reaction rate. CO2 concentration had a definite influence on the carbonation rate during the kinetically controlled stage, and the presence of SO2 at typical flue gas concentrations enhanced the direct gas-solid carbonation of steel slag. Carbonation conversions between 49.5 % and 55.5 % were achieved in a typical flue gas at 600 °C, with the maximum CO2 sequestration amount generating 88.5 kg CO 2 tslag (-1) . Direct gas-solid carbonation of steel slag showed a rapid CO2 sequestration rate, high CO2 sequestration amounts, low raw-material costs, and a large potential for waste heat utilization, which is promising for in situ carbon capture and sequestration in the steel industry.

  9. 78 FR 60316 - Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and...

    Science.gov (United States)

    2013-10-01

    ... order on carbon and certain alloy steel wire rod from Mexico. The Commission found that the respondent... COMMISSION [Investigation Nos. 701-TA-417 and 731-TA-953, 957-959, and 961-962 (Second Review)] Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and Tobago, and...

  10. 78 FR 63450 - Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and...

    Science.gov (United States)

    2013-10-24

    ... International Trade Administration, Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico... on carbon and certain alloy steel wire rod (``wire rod'') from Brazil, Indonesia, Mexico, Moldova... Brazil, Indonesia, Mexico, Moldova, Trinidad and Tobago, and Ukraine, pursuant to section 751(c) of...

  11. 78 FR 33103 - Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and...

    Science.gov (United States)

    2013-06-03

    ... COMMISSION [Investigation Nos. 701-TA-417 and 731-TA-953, 957-959, 961, and 962 (Second Review)] Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and Tobago, and Ukraine... countervailing duty order on carbon and certain alloy steel wire rod (``wire rod'') from Brazil and...

  12. 76 FR 34044 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Extension of Time Limits for the Preliminary...

    Science.gov (United States)

    2011-06-10

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE International Trade Administration Carbon and Certain Alloy Steel Wire Rod From Mexico: Extension of Time Limits... administrative review of the antidumping duty order on carbon and certain alloy steel wire rod from...

  13. 77 FR 5240 - Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan: Continuation of Antidumping Duty...

    Science.gov (United States)

    2012-02-02

    ... should the order be revoked. See Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan: Final... within a reasonably foreseeable time. See Light-Walled Rectangular Pipe and Tube From Taiwan, 77 FR 3497... International Trade Administration Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan:...

  14. 76 FR 78313 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam

    Science.gov (United States)

    2011-12-16

    ... COMMISSION Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam... United Arab Emirates, and Vietnam of circular welded carbon- quality steel pipe, provided for in... of India, Oman, the United Arab Emirates, and Vietnam.\\2\\ \\1\\ The record is defined in sec....

  15. 77 FR 45576 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2012-08-01

    ... Fair Value, and Affirmative Critical Circumstances, In Part: Certain Lined Paper Products From the... Than Fair Value: Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China, 66... Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary Results of...

  16. 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

    2016-01-01

    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 d

  17. 78 FR 25253 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure From the People's Republic of China...

    Science.gov (United States)

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Seamless Carbon and Alloy Steel Standard, Line, and Pressure From the People... seamless carbon and alloy steel standard, line, and pressure pipe ] (``seamless pipe'') from the...

  18. 78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2013-03-29

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) has completed its administrative review of the countervailing duty (CVD) order on corrosion-resistant...\\ See Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

  19. 75 FR 77615 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2010-12-13

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) published a notice of initiation of the administrative review of the antidumping duty order on corrosion... results of this review. See Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic...

  20. 76 FR 69703 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2011-11-09

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) published a notice of initiation of the administrative review of the antidumping duty order on corrosion... results of this review. See Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic...

  1. 76 FR 4291 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Partial Rescission of...

    Science.gov (United States)

    2011-01-25

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty order on corrosion- resistant carbon steel flat products from... ] requests for administrative review and partial revocation of the countervailing duty order on...

  2. 77 FR 25141 - Corrosion-Resistant Carbon Steel Flat Products From Germany and South Korea: Extension of Time...

    Science.gov (United States)

    2012-04-27

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and South Korea... of the antidumping duty (AD) orders on corrosion-resistant carbon steel flat products (CORE) from... Countervailing Duty Operations, Office 3, regarding ``Sunset Reviews of the Antidumping Duty Orders on...

  3. INFLUENCE OF CARBON CONTENT OF MARTENSITE STEELS ON HARDNESS RE-DISTRIBUTION NEAR WORN SURFACE

    Institute of Scientific and Technical Information of China (English)

    Y.P. Ma

    2002-01-01

    After three-body abrasion, the hardness re-distribution near the worn surface has aclose relationship with the carbon content of martensite steel. It is considered thatthere is a competition between the work-hardening and the temper softening, whichresults from deformation and friction heat of material. When the carbon content ofmartensite steel is below about 0.6%, the subsurface hardness distribution of materialis a softened layer sandwiched between two hardened layers, but above 0.6%C, nosoftened region appears on the hardness re-distribution curve.

  4. Effect of Rare Earths on Corrosion Resisting Properties of Carbon-Manganese Clean Steels

    Institute of Scientific and Technical Information of China (English)

    郭锋; 林勤; 孙学义

    2004-01-01

    Electrochemistry experiments were made on carbon-manganese clean steel with rare earths Ce and La respectively to observe corrosion parameters such as corrosion current icorr, and characteristic potential of pitting Eb. The results indicate that the rare earths have effect on corrosion resisting properties of carbon-manganese clean steel, and the optimum contents of La is about 0.011% (mass fraction) and Ce about 0.014% (mass fraction) respectively. The change of corrosion resistance is related to the action of rare earths on microstructure and effect on surface state of samples in the process of polarization.

  5. Influence of grain size on radiation effects in a low carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Alsabbagh, Ahmad, E-mail: ahalsabb@ncsu.edu [Department of Nuclear Engineering, North Carolina State University (United States); Valiev, Ruslan Z. [Institute of Physics of Advanced Materials, Ufa State Aviation Technical University (Russian Federation); Murty, K.L. [Department of Nuclear Engineering, North Carolina State University (United States)

    2013-11-15

    Ultra-fine grain (UFG) metals with a relatively large volume of interfaces are expected to be more radiation resistant than conventional metals; grain boundaries act as unsaturable sinks for neutron irradiation induced defects. Effects of neutron irradiation on conventional and ultra-fine grain structured carbon steel are studied using the PULSTAR reactor at NC State University to relatively low fluence (∼1.15 × 10{sup −3} dpa). The low dose irradiation of ultrafine grained carbon steel revealed minute radiation effects in contrast to the observed radiation hardening and reduction of ductility in its conventional grained counterpart.

  6. Image analysis of corrosion pit initiation on ASTM type A240 stainless steel and ASTM type A 1008 carbon steel

    Science.gov (United States)

    Nine, H. M. Zulker

    The adversity of metallic corrosion is of growing concern to industrial engineers and scientists. Corrosion attacks metal surface and causes structural as well as direct and indirect economic losses. Multiple corrosion monitoring tools are available although those are time-consuming and costly. Due to the availability of image capturing devices in today's world, image based corrosion control technique is a unique innovation. By setting up stainless steel SS 304 and low carbon steel QD 1008 panels in distilled water, half-saturated sodium chloride and saturated sodium chloride solutions and subsequent RGB image analysis in Matlab, in this research, a simple and cost-effective corrosion measurement tool has identified and investigated. Additionally, the open circuit potential and electrochemical impedance spectroscopy results have been compared with RGB analysis to gratify the corrosion. Additionally, to understand the importance of ambiguity in crisis communication, the communication process between Union Carbide and Indian Government regarding the Bhopal incident in 1984 was analyzed.

  7. 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.

  8. 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. PMID:28067318

  9. Factors affecting stress assisted corrosion cracking of carbon steel under industrial boiler conditions

    Science.gov (United States)

    Yang, Dong

    Failure of carbon steel boiler tubes from waterside has been reported in the utility boilers and industrial boilers for a long time. In industrial boilers, most waterside tube cracks are found near heavy attachment welds on the outer surface and are typically blunt, with multiple bulbous features indicating a discontinuous growth. These types of tube failures are typically referred to as stress assisted corrosion (SAC). For recovery boilers in the pulp and paper industry, these failures are particularly important as any water leak inside the furnace can potentially lead to smelt-water explosion. Metal properties, environmental variables, and stress conditions are the major factors influencing SAC crack initation and propagation in carbon steel boiler tubes. Slow strain rate tests (SSRT) were conducted under boiler water conditions to study the effect of temperature, oxygen level, and stress conditions on crack initation and propagation on SA-210 carbon steel samples machined out of boiler tubes. Heat treatments were also performed to develop various grain size and carbon content on carbon steel samples, and SSRTs were conducted on these samples to examine the effect of microstructure features on SAC cracking. Mechanisms of SAC crack initation and propagation were proposed and validated based on interrupted slow strain tests (ISSRT). Water chemistry guidelines are provided to prevent SAC and fracture mechanics model is developed to predict SAC failure on industrial boiler tubes.

  10. Microstructure and Mechanical Properties of Resistance Spot Welding Joints of Carbonitrided Low-Carbon Steels

    Science.gov (United States)

    Taweejun, Nipon; Poapongsakorn, Piyamon; Kanchanomai, Chaosuan

    2017-04-01

    Carbonitrided low-carbon steels are resistance welded in various engineering components. However, there are no reports on the microstructure and mechanical properties of their resistance spot welding (RSW) joints. Therefore, various carbonitridings were performed on the low-carbon steel sheets, and then various RSWs were applied to these carbonitrided sheets. The metallurgical and mechanical properties of the welding joint were investigated and discussed. The peak load and failure energy increased with the increases of welding current and fusion zone (FZ) size. At 11 kA welding current, the carbonitrided steel joint had the failure energy of 16 J, i.e., approximately 84 pct of untreated steel joint. FZ of carbonitrided steel joint consisted of ferrite, Widmanstatten ferrite, and untempered martensite, i.e., the solid-state transformation products, while the microstructure at the outer surfaces consisted of untempered martensite and retained austenite. The surface hardening of carbonitrided steel after RSW could be maintained, i.e., approximately 810 HV. The results can be applied to carbonitriding and RSW to achieve a good welding joint.

  11. Effect of Boron on Delayed Fracture Resistance of Medium-Carbon High Strength Spring Steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The delayed fracture behavior of medium-carbon high strength spring steel containing different amounts of boron (0. 000 5%, 0. 001 6%) was studied using sustained load delayed fracture test. The results show that delayed fracture resistance of boron containing steels is higher than that of conventional steel 60Si2MnA at the same strength level and it increases with the increase of boron content from 0. 000 5 % to 0. 001 6 %. The delayed fracture mode is mainly intergranular in the boron containing steels tempered at 350 ℃, which indicates that the addition of boron does not change the fracture character. However, the increase of boron content enlarges the size of the crack initiation area. Further study of phase analysis indicates that most boron is in solid solution, and only a very small quantity of boron is in the M3 (C, B) phase.

  12. Influence of Molybdenum Addition on Mechanical Properties of Low Carbon HSLA-100 Steel

    Directory of Open Access Journals (Sweden)

    Bogucki R.

    2014-10-01

    Full Text Available The results of mechanical properties and microstructure observation of low carbon copper bearing steel with high addition of molybdenum are presented in this paper. This steels were characterized by contents of molybdenum in the range from 1% to 3% wt. After the thermo -mechanical processing the steels were subsequently quenched and tempered at different temperatures (500-800 °C for 1h. The changes of mechanical properties as function of tempering temperature were typical for the steel with the copper addition. The sudden drop of impact resistance after tempering from 575 °C to 600 °C was caused probably by precipitates of Laves phase of type Fe2Mo.

  13. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    Directory of Open Access Journals (Sweden)

    M. Mazur

    2010-07-01

    Full Text Available The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundaries of retained austenite on rate anddevelopment of stress corrosion processes. The lowest corrosion resistance was obtained for W3 steel characterized by high contents ofmolybdenum (2.94% Mo which should be connected with the intensity precipitate processes of Fe2Mo phase. For steels W1 and W2which contents molybdenum equals 1.02% and 1.88%, respectively were obtained similar courses of corrosive cracking.

  14. The effect of various deformation processes on the corrosion behavior of casing and tubing carbon steels in sweet environment

    Science.gov (United States)

    Elramady, Alyaa Gamal

    The aim of this research project is to correlate the plastic deformation and mechanical instability of casing steel materials with corrosion behavior and surface change, in order to identify a tolerable degree of deformation for casing steel materials. While the corrosion of pipeline and casing steels has been investigated extensively, corrosion of these steels in sweet environments with respect to plastic deformation due to bending, rolling, autofrettage, or handling needs more investigation. Downhole tubular expansion of pipes (casings) is becoming standard practice in the petroleum industry to repair damaged casings, shutdown perforations, and ultimately achieve mono-diameter wells. Tubular expansion is a cold-drawing metal forming process, which consists of running conical mandrels through casings either mechanically using a piston or hydraulically by applying a back pressure. This mechanism subjects the pipes to large radial plastic deformations of up to 30 pct. of the inner diameter. It is known that cold-working is a way of strengthening materials such as low carbon steel, but given that this material will be subjected to corrosive environments, susceptibility to stress corrosion cracking (SCC) should be investigated. This research studies the effect of cold-work, in the form of cold-rolling and cold-expansion, on the surface behavior of API 5CT steels when it is exposed to a CO2-containing environment. Cold-work has a pronounced influence on the corrosion behavior of both API 5CT K55 and P110 grade steels. The lowest strength grade steel, API 5CT K55, performed poorly in a corrosive environment in the slow strain rate test. The ductile material exhibited the highest loss in strength and highest susceptibility to stress corrosion cracking in a CO 2-containing environment. The loss in strength declined with cold-rolling, which can be ascribed to the surface compressive stresses induced by cold-work. On the other hand, API 5CT P110 grade steels showed higher

  15. Adhesion of composite carbon/hydroxyapatite coatings on AISI 316L medical steel

    Directory of Open Access Journals (Sweden)

    J. Gawroński

    2009-07-01

    Full Text Available In this paper are contains the results of studies concerning the problems associated with increased of hydroxyapatite (HAp adhesion, manufactured by using Pulse Laser Deposition (PLD method, to the austenitic steel (AISI 316L through the coating of carbon interlayer on it. Carbon coating was deposited by Radio Frequency Plasma Assisted Chemical Vapour Deposition (RF PACVD method.Test results unequivocally showed that the intermediate carbon layer in a determined manner increase the adhesion of hydroxyapatite to the metallic substrate. Obtained results give rise to deal with issues of manufacturing composite bilayer – carbon film/HAp – on ready implants, casted from austenitic cast steel by lost-wax process method as well as in gypsum forms.

  16. Raising the heat and wear resistances of hardened carbon steels by friction strengthening treatment

    Science.gov (United States)

    Makarov, A. V.; Korshunov, L. G.; Malygina, I. Yu.; Solodova, I. L.

    2007-03-01

    The effect of friction treatment by a hard-alloy indenter on the microhardness and resistance to the heat-induced softening upon tempering of hardened medium-and high-carbon steels at 100-600°C is studied. The x-ray and electron microscopy methods are used to determine the causes of the increase in the heat resistance of the friction-strained steel surfaces. A comparative analysis of the effect of the hardening treatment by a hard-alloy indenter and by abrasive particles on the friction-induced heat resistance is performed for the case of high-speed friction treatment of a high-carbon laser-hardened steel.

  17. Joining of Low-Carbon Steel Sheets with Al-Based Weld

    Directory of Open Access Journals (Sweden)

    Boczkal G.

    2016-03-01

    Full Text Available The analysis of the connection steel/Al/steel made by resistance welding was performed. The used low-carbon steel had low content of carbon and other elements, aluminum was of 99.997 wt.% Al purity. Formation of various FeAl intermetallic phases found in the phase diagram depending on the duration of the process was analyzed. Two distinctively different types of structure depending on time of welding were observed: 1 hypoeutectic structure for samples processed for 5 s, and 2 eutectic structure for samples processed for 10 s and more. The shear test showed increase of mechanical properties of the connection for the samples welded 10 s.

  18. EFFECT OF ELECTRIC FIELD ON THE AUSTENIZATION OF A LOW CARBON STEEL

    Institute of Scientific and Technical Information of China (English)

    X.T.Liu; J.Z.Cui

    2004-01-01

    With an electric field during austenitizing, the martensite transformation of the low carbon steel was promoted, and more martensite were obtained. The electric field promotes the homogeneity of carbon, and reduces the free energy of austenite. The critical neuclus r* and the critical driving force G* responsible for the nucleation of proeutectoid ferrite were increased. As a result of which the diffusion controlled proeuctoid ferrite transformation was retarded and the hardenability was improved.

  19. Effect of commercial metals (Al, Cu, carbon steel, and Zn) on the oxidation of soy-biodiesel

    Science.gov (United States)

    Díaz-Ballote, L.; Castillo-Atoche, A.; Maldonado, L.; Ruiz-Gómez, M. A.; Hernández, E.

    2016-09-01

    The effect of aluminum, copper, low carbon steel and zinc on the oxidation of biodiesel derived from soybean oil is studied using residual mass curves from thermogravimetry. Biodiesel is oxidized in the presence and absence of each metal in static conditions and exposed to ambient air. Oxidized biodiesel parameters are confirmed by viscosity measurements, nuclear magnetic resonance and Fourier transform infrared spectroscopy. The results showed that the metals do not negatively influence the oxidative stability of biodiesel and it can even be considered that they slightly inhibit the oxidation process. This behavior was ascribed to a depletion of dissolved oxygen in biodiesel due to oxidation of the metal and the low solubility of oxygen at high temperature.

  20. Carbonated aqueous media for quench heat treatment of steels

    Science.gov (United States)

    Nayak, U. Vignesh; Rao, K. M. Pranesh; Pai, M. Ashwin; Prabhu, K. Narayan

    2016-09-01

    Distilled water and polyalkylene glycol (PAG)-based aqueous quenchants of 5 and 10 vol.% with and without carbonation were prepared and used as heat transfer media during immersion quenching. Cooling curves were recorded during quenching of an inconel 600 cylindrical probe instrumented with multiple thermocouples. It was observed that the vapor stage duration was prolonged and the wetting front ascended uniformly for quenching with carbonated media. The cooling data were analyzed by determining the critical cooling parameters and by estimating the spatially dependent probe/quenchant interfacial heat flux transients. The study showed significantly reduced values of heat transfer rate for carbonated quenchants compared to quenchants without carbonation. Further, the reduction was more pronounced in the case of PAG-based carbonated quenchants than carbonated distilled water. The results also showed the dependence of heat transfer characteristics of the carbonated media on polymer concentration. The effect of quench uniformity on the microstructure of the material was assessed.

  1. The influence of aluminum and carbon on the abrasion resistance of high manganese steels

    Science.gov (United States)

    Buckholz, Samuel August

    Abrasive wear testing of lightweight, austenitic Fe-Mn-Al-C cast steel has been performed in accordance with ASTM G65 using a dry sand, rubber wheel, abrasion testing apparatus. Testing was conducted on a series of Fe-30Mn-XAl-YC-1Si-0.5Mo chemistries containing aluminum levels from 2.9 to 9.5 wt.% and carbon levels from 0.9 to 1.83 wt.%. Solution treated materials having an austenitic microstructure produced the highest wear resistance. Wear resistance decreased with higher aluminum, lower carbon, and higher hardness after age hardening. In the solution treated condition the wear rate was a strong function of the aluminum to carbon ratio and the wear rate increased with a parabolic dependence on the Al/C ratio, which ranged from 1.8 to 10.2. Examination of the surface wear scar revealed a mechanism of plowing during abrasion testing and this method of material removal is sensitive to work hardening rate. Work hardening behavior was determined from tensile tests and also decreased with increasing Al/C ratio and after aging hardening. The loss of wear resistance is related to short range ordering of Al and C in the solution treated materials and kappa-carbide precipitation in age hardened materials and both contribute to planar slip and lower work hardening rates. A high carbon tool steel (W1) and a bainitic low alloy steel (SAE 8620) were also tested for comparison. A lightweight steel containing 6.5 wt.% Al and 1.2 wt.% C has wear resistance comparable to within 5% of the bainitic SAE 8620 steel forging currently used for the Bradley Fighting Vehicle track shoe and this cast Fe-Mn-Al-C steel, at equivalent tensile properties, would be 10% lighter.

  2. Bainite Formation in Medium-Carbon Low-Silicon Spring Steels Accounting for Chemical Segregation

    NARCIS (Netherlands)

    Goulas, C.; Mecozzi, M.G.; Sietsma, J.

    2016-01-01

    In this paper, the effect of chemical inhomogeneity on the isothermal bainite formation is investigated in medium-carbon low-silicon spring steel by dilatometry and microscopy. The analysis of the microstructure at different times during transformation shows that chemical segregation of substitution

  3. Effect of Additional Sulfide and Thiosulfate on Corrosion of Q235 Carbon Steel in Alkaline Solutions

    Directory of Open Access Journals (Sweden)

    Bian Li Quan

    2016-01-01

    Full Text Available This paper investigated the effect of additional sulfide and thiosulfate on Q235 carbon steel corrosion in alkaline solutions. Weight loss method, scanning electron microscopy (SEM equipped with EDS, X-ray photoelectron spectroscopy (XPS, and electrochemical measurements were used in this study to show the corrosion behavior and electrochemistry of Q235 carbon steel. Results indicate that the synergistic corrosion rate of Q235 carbon steel in alkaline solution containing sulfide and thiosulfate is larger than that of sulfide and thiosulfate alone, which could be due to redox reaction of sulfide and thiosulfate. The surface cracks and pitting characteristics of the specimens after corrosion were carefully examined and the corrosion products film is flake grains and defective. The main corrosion products of specimen induced by S2− and S2O32- are FeS, FeS2, Fe3O4, and FeOOH. The present study shows that the corrosion mechanism of S2− and S2O32- is different for the corrosion of Q235 carbon steel.

  4. About Reverted Austenite in Carburized Layers of Low-Carbon Martensitic Steels

    Science.gov (United States)

    Ivanov, A. S.; Bogdanova, M. V.; Vylezhnev, V. P.

    2015-05-01

    Processes of surface hardening in low-carbon martensitic steel 24Kh2G2NMFTB under carburizing and subsequent quenching from the intercritical temperature range are studied. Special features of formation of reverted austenite with high strength and stability are considered.

  5. DEFORMATION AND FRACTURE MICROPROCESSES OF EXPLOSIVELY LOADED LOW-CARBON STEELS UNDER TENSION

    OpenAIRE

    Larionov, V; Yakovleva, S.

    1991-01-01

    The mechanism of strength properties formation in low-carbon steels subjected to explosive treatment is investigated. With this aim in view, the features inherent to plastic deformation and fracture microprocesses have been studied. A quantitative analysis of the microinhomogeneous plastic deformation characteristics has been carried out.

  6. Cumalative Distribution Functions for the Relative Humidity Thresholds for the Onset of Carbon Steel Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon

    1998-05-13

    The purpose of this calculation is to process the cumulative distribution functions (CDFs) characterizing the relative humidity (RH) thresholds for the onset of carbon steel corrosion provided by expert elicitation and minimize the set of values to 200 points for use in WAPDEG.

  7. Martensitic transformation and stress partitioning in a high-carbon steel

    DEFF Research Database (Denmark)

    Villa, Matteo; Grumsen, Flemming Bjerg; Pantleon, Karen;

    2012-01-01

    Martensitic transformation in a high-carbon steel was investigated with (synchrotron) X-ray diffraction at sub-zero Celsius temperature. In situ angular X-ray diffraction was applied to: (i) quantitatively determine the fractions of retained austenite and martensite; and (ii) measure the evolution...

  8. Fabrication of cast carbon steel with ultrafine TiC particles

    Institute of Scientific and Technical Information of China (English)

    Sang-Hoon LEE; Jin-Ju PARK; Sung-Mo HONG; Byoung-Sun HAN; Min-Ku LEE; Chang-Kyu RHEE

    2011-01-01

    The carbon steels dispersed with ultrafine TiC particles were fabricated by conventional casting method. The casting process is more economical than other available routes for metal matrix composite production, and the large sized components to be fabricated in short processing time. However, it is extremely difficult to obtain uniform dispersion of ultrafine ceramic particles in liquid metals due to the poor wettability and the specific gravity difference between the ceramic particle and metal matrix, In order to solve these problems, the mechanical milling (MM) and surface-active processes were introduced. As a result, Cu coated ultrafine TiC powders made by MM process using high energy ball milling machine were mixed with Sn powders as a surfactant to get better wettability by lowering the surface tension of carbon steel melt, The microstructural investigations by OM show that ultrafine TiC particles are distributed uniformly in carbon steel matrix. The grain sizes of the cast matrix with ultrafine TiC particles are much smaller than those without ultrafine TiC particles. This is probably due to the fact that TiC particles act as nucleation sites during solidification. The wear resistance of cast carbon steel composites added with MMed TiC/Cu-Sn powders is improved due to grain size refinement.

  9. Interaction of carbon-vacancy complex with minor alloying elements of ferritic steels

    Science.gov (United States)

    Bakaev, A.; Terentyev, D.; He, X.; Zhurkin, E. E.; Van Neck, D.

    2014-08-01

    Interstitial carbon, dissolved in bcc matrix of ferritic steels, plays an important role in the evolution of radiation-induced microstructure since it exhibits strong interaction with vacancies. Frequent formation and break-up of carbon-vacancy pairs, occurring in the course of irradiation, affect both kinetics of the accumulation of point defect clusters and carbon spatial distribution. The interaction of typical alloying elements (Mn, Ni, Cu, Si, Cr and P) in ferritic steels used as structural materials in nuclear reactors with a carbon-vacancy complex is analyzed using ab initio techniques. It is found that all the considered solutes form stable triple clusters resulting in the increase of the total binding energy by 0.2-0.3 eV. As a result of the formation of energetically favourable solute-carbon-vacancy triplets, the dissociation energy for vacancy/carbon emission is also increased by ∼0.2-0.3 eV, suggesting that the solutes enhance thermal stability of carbon-vacancy complex. Association of carbon-vacancy pairs with multiple solute clusters is found to be favorable for Ni, Cu and P. The energetic stability of solute(s)-carbon-vacancy complexes was rationalized on the basis of pairwise interaction data and by analyzing the variation of local magnetic moments on atoms constituting the clusters.

  10. Effect of microstructure of carbon steel on magnetite formation in simulated Hot Conditioning environment of nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Prafful Kumar, E-mail: prafful@barc.gov.in; Kiran Kumar, M.; Kain, Vivekanand

    2015-09-15

    Highlights: • Heat treatments used to tailor microstructure of a low and a high carbon steel. • Oxide growth rates established in Hot Conditioning simulated environment. • Only magnetite formed on all microstructural conditions of both the steels. • Growth rate was higher for all microstructures of high carbon steel upto 72 h. • After 72 h growth rate stabilized in narrow band for all microstructures of a steel. - Abstract: The objective of present investigation is to establish the role of starting microstructure of carbon steel on the magnetite formation behaviour in Hot Conditioning simulated environment. Two grades of carbon steel (low and high carbon) were subjected to selective heat-treatments to generate different microstructures: martensite, tempered martensite and modified ferrite–pearlite. Oxidation was carried out in lithiated water of pH 10–10.2 in a static autoclave at 270 °C. The results of the investigation clearly establish that: (a) high carbon steel (0.63% C) showed a relatively higher rate of oxidation over the low carbon (0.08% C) grade at all the test durations and (b) the oxidation rates for both the grades were sensitive to microstructural differences at initial stages of oxidation while the differences narrowed down after 72 h of exposure. The oxide formed was established to be magnetite on all the specimens.

  11. A facile electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yi [State Key Lab of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Rd. 8, Xindu District, Chengdu City, Sichuan Province 610500 (China); School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu City, Sichuan Province 610500 (China); He, Yi, E-mail: chemheyi@swpu.edu.cn [State Key Lab of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Rd. 8, Xindu District, Chengdu City, Sichuan Province 610500 (China); School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu City, Sichuan Province 610500 (China); Luo, Pingya, E-mail: luopy@swpu.edu.cn [State Key Lab of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Rd. 8, Xindu District, Chengdu City, Sichuan Province 610500 (China); Chen, Xi; Liu, Bo [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu City, Sichuan Province 610500 (China)

    2016-04-15

    Graphical abstract: - Highlights: • A facile fabrication of superhydrophobic film was obtained on carbon steel. • Composition of superhydrophobic film is iron palmitate. • The film exhibits excellent chemical stability and good self-cleaning effect. • Corrosion of C45 steel is significantly inhibited with superhydrophobic surface. - Abstract: Superhydrophobic Fe film with hierarchical micro/nano papillae structures is prepared on C45 steel surface by one-step electrochemical method. The superhydrophobic surface was measured with a water contact angle of 160.5 ± 0.5° and a sliding angle of 2 ± 0.5°. The morphology of the fabricated surface film was characterized by field emission scanning electron microscopy (FE-SEM), and the surface structure seems like accumulated hierarchical micro-nano scaled particles. Furthermore, according to the results of Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS), the chemical composition of surface film was iron complex with organic acid. Besides, the electrochemical measurements showed that the superhydrophobic surface improved the corrosion resistance of carbon steel in 3.5 wt.% NaCl solution significantly. The superhydrophobic layer can perform as a barrier and provide a stable air–liquid interface which inhibit penetration of corrosive medium. In addition, the as-prepared steel exhibited an excellent self-cleaning ability that was not favor to the accumulation of contaminants.

  12. Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: laboratory investigation.

    Science.gov (United States)

    Stipanicev, Marko; Turcu, Florin; Esnault, Loïc; Rosas, Omar; Basseguy, Régine; Sztyler, Magdalena; Beech, Iwona B

    2014-06-01

    Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -800corrosion rate, expressed as 1/(Rp/Ω), was lower in the inoculated seawater though they varied significantly on both reactors. Initial and final corrosion rates were virtually identical, namely initial 1/(Rp/Ω)=2×10(-6)±5×10(-7) and final 1/(Rp/Ω)=1.1×10(-5)±2.5×10(-6). Measured data, including electrochemical noise transients and statistical parameters (0.0545), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.

  13. Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

    Institute of Scientific and Technical Information of China (English)

    Long Wan; Yong-xian Huang; Shi-xiong L; Ti-fang Huang; Zong-liang L

    2016-01-01

    In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liq-uid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation (LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region ap-peared when shear movement was from copper to iron.

  14. Hot Deformation Behavior and Dynamic Recrystallization of Medium Carbon LZ50 Steel

    Science.gov (United States)

    Du, Shiwen; Chen, Shuangmei; Song, Jianjun; Li, Yongtang

    2017-01-01

    Hot deformation and dynamic recrystallization behaviors of a medium carbon steel LZ50 were systematically investigated in the temperature range from 1143 K to 1443 K (870 °C to 1170 °C) at strain rates from 0.05 to 3s-1 using a Gleeble-3500 thermo-simulation machine. The flow stress constitutive equation for hot deformation of this steel was developed with the two-stage Laasraoui equation. The activation energy of the tested steel was 304.27 KJ/mol, which was in reasonable agreement with those reported previously. The flow stress of this steel in hot deformation was mainly controlled by dislocation climb during their intragranular motion. The effect of Zener-Hollomon parameter on the characteristic points of the flow curves was studied, and the dependence of critical strain on peak strain obeyed a linear equation. Dynamic recrystallization was the most important softening mechanism for the tested steel during hot deformation. Kinetic equation of this steel was also established based on the flow stress. The austenite grain size of complete dynamic recrystallization was a power law function of Zener-Hollomon parameter with an exponent of -0.2956. Moreover, the microstructures induced under different deformation conditions were analyzed.

  15. Hot Deformation Behavior and Dynamic Recrystallization of Medium Carbon LZ50 Steel

    Science.gov (United States)

    Du, Shiwen; Chen, Shuangmei; Song, Jianjun; Li, Yongtang

    2017-03-01

    Hot deformation and dynamic recrystallization behaviors of a medium carbon steel LZ50 were systematically investigated in the temperature range from 1143 K to 1443 K (870 °C to 1170 °C) at strain rates from 0.05 to 3s-1 using a Gleeble-3500 thermo-simulation machine. The flow stress constitutive equation for hot deformation of this steel was developed with the two-stage Laasraoui equation. The activation energy of the tested steel was 304.27 KJ/mol, which was in reasonable agreement with those reported previously. The flow stress of this steel in hot deformation was mainly controlled by dislocation climb during their intragranular motion. The effect of Zener-Hollomon parameter on the characteristic points of the flow curves was studied, and the dependence of critical strain on peak strain obeyed a linear equation. Dynamic recrystallization was the most important softening mechanism for the tested steel during hot deformation. Kinetic equation of this steel was also established based on the flow stress. The austenite grain size of complete dynamic recrystallization was a power law function of Zener-Hollomon parameter with an exponent of -0.2956. Moreover, the microstructures induced under different deformation conditions were analyzed.

  16. Mineral CO2 sequestration by steel slag carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.; Comans, R.N.J.

    2005-01-01

    Mineral CO2 sequestration, i.e., carbonation of alkaline silicate Ca/Mg minerals, analogous to natural weathering processes, is a possible technology for the reduction of carbon dioxide emissions to the atmosphere. In this paper, alkaline Ca-rich industrial residues are presented as a possible feeds

  17. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accclerated carbon ions with linear energy transfers of 125.5, 200 and 700 keV/μm were measured, respectively. Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves. They are 7.86±0.17, 10.44±1.11 and 32.32±3.58 μm2 in turn. With the surviving response of V79 cells to 60Co γ-rays as a reference value, relative biological effectiveness at 10%, 20%, 50% and 80% survival levels were given for the accelerated carbon ions. The results showed that carbon ions with LET of 125.5 keV/μm had a higher value of RBE at all the four survival levels than the carbon ions with other LETs. It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200 keV/μm for carbon ions.

  18. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    LIQiang; ZHOUGuang-Ming; 等

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accelerated carbon ions with linear energy transfers of 125.5,200 and 700keV/um were measured,respectively,Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves.They are 7.86±0.17,10.44±1.11 and 32.32±3.59um2 in turn.With the surviving response of V79 cells to 60Co γ-rays as a reference value,relative biological effectiveness at 10%,20%,50%and 80% survival levels were given for the accelerated carbon ions,The results showed that carbon ions with LET of 125.5keV/um had a higher value of RBE at all the four survival levels than the carbon ions with other LETs.It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200keV/um for carbon ions.

  19. Finite Element Analysis of Fire Truck Chassis for Steel and Carbon Fiber Materials

    Directory of Open Access Journals (Sweden)

    Salvi Gauri Sanjay

    2014-07-01

    Full Text Available Chassis is the foremost component of an automobile that acts as the frame to support the vehicle body. Hence the frame ought to be very rigid and robust enough to resist shocks vibrations and stresses acting on a moving vehicle. Steel in its numerous forms is commonly used material for producing chassis and overtime alumimium has acquired its use. However, in this study traditional materials are replaced with ultra light weight carbon fiber materials. High strength and low weight of carbon fibers makes it ideal for manufacturing automotive chassis. This paper depicts the modal and static structural analysis of TATA 407 fire truck chassis frame for steel as well as carbon fibers. From the analyzed results, stress, strain and total deformation values were compared for both the materials. Since it is easy to analyze structural systems by finite element method, the chassis is modified using PRO-E and the Finite Element Analysis is performed on ANSYS workbench.

  20. Effect of temper rolling on the bake-hardening behavior of low carbon steel

    Institute of Scientific and Technical Information of China (English)

    Chun-fu Kuang; Shen-gen Zhang; Jun Li; Jian Wang; Pei Li

    2015-01-01

    In a typical process, low carbon steel was annealed at two different temperatures (660°C and 750°C), and then was temper rolled to improve the mechanical properties. Pre-straining and baking treatments were subsequently carried out to measure the bake-hardening (BH) values. The influences of annealing temperature and temper rolling on the BH behavior of the steel were investigated. The results indicated that the microstructure evolution during temper rolling was related to carbon atoms and dislocations. After an apparent increase, the BH value of the steel significantly decreased when the temper rolling reduction was increased from 0%to 5%. This was attributed to the increase in solute carbon concentration and dislocation density. The maximum BH values of the steel annealed at 660°C and 750°C were 80 MPa and 89 MPa at the reductions of 3%and 4%, respectively. Moreover, increasing the annealing temperature from 660 to 750°C resulted in an ob-vious increase in the BH value due to carbide dissolution.

  1. Nanocrystallization of aluminized surface of carbon steel for enhanced resistances to corrosion and corrosive wear

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China); Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Li, D.Y., E-mail: dongyang.li@ualberta.c [Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Shang, C.J. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China)

    2009-12-15

    Aluminizing is often used to improve steel's resistances to corrosion, oxidation and wear. This article reports our recent attempts to further improve aluminized carbon steel through surface nanocrystallization for higher resistances to corrosion and corrosive wear. The surface nanocrystallization was achieved using a process combining sandblasting and recovery heat treatment. The entire surface modification process includes dipping carbon steel specimens into a molten Al pool to form an Al coat, subsequent diffusion treatment at elevated temperature to form an aluminized layer, sandblasting to generate dislocation network or cells, and recovery treatment to turn the dislocation cells into nano-sized grains. The grain size of the nanocrystallized aluminized surface layer was in the range of 20-100 nm. Electrochemical properties, electron work function (EWF), and corrosive wear of the nanocrystalline alloyed surfaces were investigated. It was demonstrated that the nanocrystalline aluminized surface of carbon steel exhibited improved resistances to corrosion, wear and corrosive wear. The passive film developed on the nanocrystallized aluminized surface was also evaluated in terms of its mechanical properties and adherence to the substrate.

  2. The anaerobic corrosion of carbon steel in alkaline media – Phase 2 results

    Directory of Open Access Journals (Sweden)

    Fennell P.A.H.

    2013-07-01

    Full Text Available In the Belgian Supercontainer concept a carbon steel overpack will surround high-level waste and spent fuel containers and be encased in a cementitious buffer material. A programme of research was carried out to investigate and measure the rate of anaerobic corrosion of carbon steel in an artificial alkaline porewater that simulates the aqueous phase in the cementitious buffer material. The corrosion rates were measured by monitoring hydrogen evolution using a manometric gas cell technique and by applying electrochemical methods. Phase 2 of the programme has repeated and extended previous Phase 1 measurements of the effects of radiation, temperature and chloride concentration of the anaerobic corrosion rate. This paper provides an update on the results from Phase 2 of the programme. The results confirm previous conclusions that the long-term corrosion rate of carbon steel in alkaline simulated porewater is determined by the formation of a thin barrier layer and a thicker outer layer composed of magnetite. Anaerobic corrosion of steel in cement requires an external supply of water.

  3. Effects of tantalum content on the microstructure and mechanical properties of low-carbon RAFM steel

    Science.gov (United States)

    Chen, Jianguo; Liu, Chenxi; Liu, Yongchang; Yan, Biyu; Li, Huijun

    2016-10-01

    In order to explore the influence of tantalum content on the microstructure and mechanical properties of low carbon RAFM (reduced activation ferritic/martensitic) steels, three low carbon RAFM steels with different tantalum contents (0%, 0.027%, 0.073%) were designed. The precipitation behavior and effect of precipitates on the mechanical properties of the Low-C RAFM steel were investigated. The results indicate that increase of tantalum content causes decrease of the prior austenite grain size and the amount of M23C6 carbides precipitated along prior austenite grain boundaries and packet boundaries as well as increase of the amount of MX nano-sized particles within intragranular regions. The impact properties of low carbon RAFM steels are excellent regardless of the tantalum content. The impact properties and hardness are obviously improved by increasing tantalum content, which may be related to increase of the number of MX and decrease of M23C6. Furthermore, the tensile properties at elevated temperature below 600 °C are hardly changed with increase of tantalum content, yet those at 800 °C are improved with increasing tantalum content. This implies that MX carbides would be more important for tensile properties at higher temperature.

  4. Cladding of the carbon fiber on the steel base using electron beam in the air atmosphere

    Science.gov (United States)

    Losinskaya, A.; Lozhkina, E.; Bardin, A.; Stepanova, N.

    2016-11-01

    The formation of the high-carbon layers on the low-carbon steel (0.18 % C) using the method of electron-beam partial melting of the carbon fibers is considered. A 1.4 MeV electron beam extracted into air was used. The features of the cladded layers formation using different binders for a reliable fixation of the cladding material are studied. It is revealed that the best results are obtained using the phenol-formaldehyde glue as the binder. A 3 mm thickness layers with 2.2 % C are shown to be formed.

  5. Computer Simulation of Ferrite Transformation during Hot Working of Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Yunbo XU; Yongmei YU; Xianghua LIU; Guodong WANG

    2004-01-01

    On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing conditions. Results indicate that Ar3d temperature mostly depended on alloying composition and processing parameters. Ar3d increased as strain rate or strain increased for the same steel grade. In view of enhancement of deformation on transformation,the basic kinetics model was established to simulate deformation induced transformation behavior, using which the influence of the deformation stored energy and effective deformation ledge on the nucleation and growth can be considered. The simulated results are in good agreement with experiment results.

  6. Ni-P-SiC composite coatings electroplated on carbon steel assisted by mechanical attrition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Ni-P-SiC composite coatings were electroplated on carbon steel substrate assisted by mechanical attrition(MA).The MA action was conducted by dispersing glass balls on the cathodic surface,vibrating in the horizontal direction.The experimental results show that,under the assistant of MA action,the adhesion of Ni-P-SiC coating on the steel substrate can be improved effectively,and the Ni-P-SiC coatings exhibit a crystallized structure and Ni-P matrix can combine tightly with SiC particles,and the hardness and...

  7. Dynamic Recrystallization and Grain Growth Behavior of 20SiMn Low Carbon Alloy Steel

    Institute of Scientific and Technical Information of China (English)

    DONG Lanfeng; ZHONG Yuexian; MA Qingxian; YUAN Chaolong; MA Lishen

    2008-01-01

    A senes of thermodynamics experiments were used to optimize the hot forging process of 20SiMn low-carbon alloy steel.A dynamic recrystallization and grain growth model was developed for the 20SiMn steel for common production conditions of heavy forgings by doing a nonlinear curve fit of the expenment data.Optimized forging parameters were developed based on the control of the dynamic recrystallization and the MnS secondary phase.The data shows that the initial grain size and the MnS secondary phase all affect the behavior of the 20SiMn dynamic recrystallization and grain growth.

  8. MODELING OF FERRITE GRAIN GROWTH OF LOW CARBON STEELS DURING HOT ROLLING

    Institute of Scientific and Technical Information of China (English)

    Y.T. Zhang; D.Z. Li; Y.Y. Li

    2002-01-01

    For most commercial steels the prediction of the final properties depends on accuratelycalculating the room temperature ferrite grain size. A grain growth model is proposedfor low carbon steels Q235B during hot rolling. By using this model, the initial ferritegrain size after continuous cooling and ferrite grain growing in coiling procedure canbe predicted. Finally, in-plant trials were performed in the hot strip mill of Ansteel.The calculated final ferrite grain sizes are in good agreement with the experimentalones. It is helpful both for simulation of microstructure evolution and prediction ofmechanical properties.

  9. 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.

  10. Estimation on gas generation and corrosion rates of carbon steel, stainless steel and zircaloy in alkaline solutions under low oxygen condition

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, Morihiro; Honda, Akira [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan); Nishimura, Tsutomu; Wada, Ryutaro [Kobe Steel Ltd., Engineering Company, Energy and Nuclear System Center, Osaka (Japan)

    2002-06-01

    Hydrogen gas generated by corrosion of metals in TRU waste repository may degrade the function of the engineered barrier system for nuclide migration. Therefore, estimation of gas generation rates of metals under the repository condition is important. In this study, we obtained gas generation rates of carbon steel, stainless steel and zircaloy in alkaline solutions under low oxygen conditions and evaluated the corrosion rates based on these data in order to compare with the published data. The magnitude of corrosion rates of carbon steel, stainless steel and zircaloy were 10{sup -1} {mu}m/y, 10{sup -2} {mu}m/y and 10{sup -3} {mu}m/y, respectively. These values agreed with the published corrosion rates from gas generation rates by others. (author)

  11. 76 FR 36081 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil and Japan: Revocation of the...

    Science.gov (United States)

    2011-06-21

    ... (``IF'')) steels, high strength low alloy (``HSLA'') steels, and the substrate for motor lamination... titanium and/or niobium added to stabilize carbon and nitrogen elements. HSLA steels are recognized as...-quality steel products are covered by the orders, including: vacuum degassed, fully stabilized;...

  12. Formation of fouling deposits on a carbon steel surface from Colombian heavy crude oil under preheating conditions

    Science.gov (United States)

    Muñoz Pinto, D. A.; Cuervo Camargo, S. M.; Orozco Parra, M.; Laverde, D.; García Vergara, S.; Blanco Pinzon, C.

    2016-02-01

    Fouling in heat exchangers is produced by the deposition of undesired materials on metal surfaces. As fouling progresses, pressure drop and heat transfer resistance is observed and therefore the overall thermal efficiency of the equipment diminishes. Fouling is mainly caused by the deposition of suspended particles, such as those from chemical reactions, crystallization of certain salts, and some corrosion processes. In order to understand the formation of fouling deposits from Colombian heavy oil (API≈12.3) on carbon steel SA 516 Gr 70, a batch stirred tank reactor was used. The reactor was operated at a constant pressure of 340psi while varying the temperature and reaction times. To evaluate the formation of deposits on the metal surfaces, the steel samples were characterized by gravimetric analysis and Scanning Electron Microscopy (SEM). On the exposed surfaces, the results revealed an increase in the total mass derived from the deposition of salt compounds, iron oxides and alkaline metals. In general, fouling was modulated by both the temperature and the reaction time, but under the experimental conditions, the temperature seems to be the predominant variable that controls and accelerates fouling.

  13. The Inhibitive Potential of Arecaceae Extract on the Corrosivity of Aluminium based Matrix Composite and Medium Carbon Steel in Different Media

    Directory of Open Access Journals (Sweden)

    Paul Aondona IHOM

    2013-06-01

    Full Text Available In this research study, the inhibitive potential of Arecaceae extract on the corrosivity of aluminium based matrix composite and medium carbon steel in different media have been undertaken. The composite and the carbon steel were exposed in 0.5M NaOH and 0.5M HCl solutions as the control solutions. The Arecaceae extract from the fruit juice was added in volume percentages of 5%v/v and 10%v/v. The exposure time covered 12 days, and the monitored temperature range during the exposure time was 25-39°C. The result indicated that the most corrosive media were those without the Arecaceae inhibitor; where corrosion rate ranged from 0.106mpy to 0.409mpy. The medium carbon steel did not show any sign of corrosion in the 0.5M NaOH solution. Arecaceae inhibitor addition of 5%v/v gave optimum corrosion rate reduction; the corrosion rate was in the range of 0.018mpy to 0.199mpy. Although the lowest range of 0.013mpy to 0.192mpy was obtained with 10%v/v of Arecaceae, however on the overall performance the 5%v/v of Arecaceae was better. The inhibition of corrosion by Arecaceae was as a result of adsorption and phase layers on the surface of the metals.

  14. 碳钢在海水环境中的腐蚀和污损特性研究%Corrosion and Biofouling Character of Carbon Steel in Seawater

    Institute of Scientific and Technical Information of China (English)

    杨海洋; 黄桂桥

    2013-01-01

    Change of corrosion rate of carbon steels in seawater was discussed. Corrosion and biofouling character of carbon steels in seawater were summarized. The result showed that corrosion rate of the carbon steel exposed to seawater decreases with time, which is stable after one or two years of exposure;the corrosion course can be divided into the process dynamics controlled stage, the oxygen diffusion controlled stage, the growth of fouling organism controlled stage, and microbiological corrosion controlled stage.%讨论了碳钢材料在海水环境中的腐蚀速率随时间的变化情况,总结了碳钢在海水中不同暴露阶段的腐蚀和生物污损特性。结果显示,碳钢在海水中的腐蚀速度随时间延长而下降,暴露1~2年后腐蚀速率变化不显著,其腐蚀过程可分为腐蚀过程控制阶段、氧扩散控制阶段、污损生物成长控制阶段和微生物腐蚀控制阶段等4个阶段。

  15. Predictive Models for the Determination of Pitting Corrosion Versus Inhibitor Concentrations and Temperature for Radioactive Sludge in Carbon Steel Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.I.

    1998-10-06

    Statistical models have been developed to predict the occurrence of pitting corrosion in carbon steel waste storage tanks exposed to radioactive nuclear waste. The levels of nitrite concentrations necessary to inhibit pitting at various temperatures and nitrate concentrations were experimentally determined via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based on various statistical analyses of the experimental data. Feed-forward Artificial Neural Network (ANN) models, trained using the Back-Propagation of Error Algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models developed using the same data.

  16. Precipitation behavior of carbides in high-carbon martensitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Qin-tian; Li, Jing; Shi, Cheng-bin; Yu, Wen-tao; Shi, Chang-min [University of Science and Technology, Beijing (China). State Key Laboratory of Advanced Metallurgy; Li, Ji-hui [Yang Jiang Shi Ba Zi Group Co., Ltd, Guangdong (China)

    2017-01-15

    A fundamental study on the precipitation behavior of carbides was carried out. Thermo-calc software, scanning electron microscopy, electron probe microanalysis, transmission electron microscopy, X-ray diffractometry and high-temperature confocal laser scanning microscopy were used to study the precipitation and transformation behaviors of carbides. Carbide precipitation was of a specific order. Primary carbides (M7C3) tended to be generated from liquid steel when the solid fraction reached 84 mol.%. Secondary carbides (M7C3) precipitated from austenite and can hardly transformed into M23C6 carbides with decreasing temperature in air. Primary carbides hardly changed once they were generated, whereas secondary carbides were sensitive to heat treatment and thermal deformation. Carbide precipitation had a certain effect on steel-matrix phase transitions. The segregation ability of carbon in liquid steel was 4.6 times greater that of chromium. A new method for controlling primary carbides is proposed.

  17. Effect of boron on hot strips of low carbon steel produced by compact strip production

    Institute of Scientific and Technical Information of China (English)

    Hao Yu; Yonglin Kang

    2008-01-01

    The effect of boron on hot strips of low carbon steel produced by compact strip production (CSP) to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low alloy steel. The mechanical properties and microstructural evolution of the hot strip were studied using optical microscopy and tensile tests. By means of an electrolytic disso- lution technique and Thermo-Cal calculation, the precipitates containing boron were analyzed and detected. From the electron back- scattered diffraction analysis, it can be deciphered whether the microstructure has recrystallized or not. Furthermore, the effect of boron segregation on the recrystallization or non-recrystallization conditions can be distinguished. The segregation behavior of boron was investigated in boron-containing steel. The nonequilibrium segregation of boron during processing was discussed on the basis of the forming complexes with vacancies that migrate to the boundaries prior to annihilation, which was confirmed by the subsequent cold rolling with annealing experiments.

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

    Science.gov (United States)

    Finkenstadt, Victoria L; Côté, Gregory L; Willett, J L

    2011-06-01

    Corrosion of metals is a serious and challenging problem faced worldwide by industry. Purified Leuconostoc mesenteroides exopolysaccharide (EPS) coatings, cast from aqueous solution, inhibited the corrosion of low-carbon steel as determined by electrochemical impedance spectroscopy (EIS). There were two different corrosion behaviors exhibited when EPS films from different strains were cast onto the steel. One EPS coating reacted immediately with the steel substrate to form an iron (III) oxide layer ("rust") during the drying process while another did not. The samples that did not flash corrode had higher corrosion inhibition and formed an iron (II) passivation layer during EIS testing that persisted after the cells were disassembled. Corrosion inhibition was strain-specific as polysaccharides with similar structure did not have the same corrosion potential.

  19. Inhibition of carbon steel corrosion in 1 M HCl medium by potassium thiocyanate

    Directory of Open Access Journals (Sweden)

    A. Anejjar

    2014-04-01

    Full Text Available The effect of potassium thiocyanate (KSCN on the corrosion of carbon steel (C-steel in 1 M HCl has been investigated in relation to the concentration of the inhibitor by polarization curves, electrochemical impedance spectroscopy and weight loss measurement. The results obtained revealed that this compound is a good mixed type inhibitor with predominant cathodic effectiveness. The effect of temperature on the corrosion behavior with the addition of optimal concentration of KSCN was studied in the temperature range 298–328 K. The value of inhibition efficiency decreases slightly with the increase in temperature. Changes in impedance parameters (charge transfer resistance, Rct, and double layer capacitance, Cdl were indicative of adsorption of KSCN on the metal surface, leading to the formation of a protective film. Adsorption of KSCN on the C-steel surface was found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined and discussed.

  20. Hot Deformation Behavior and Microstructural Evolution of a Medium Carbon Vanadium Microalloyed Steel

    Science.gov (United States)

    Cutrim, Rialberth M.; Rodrigues, Samuel F.; Reis, Gedeon S.; Silva, Eden S.; Aranas, Clodualdo; Balancin, Oscar

    2016-11-01

    Hot forging of steel requires application of large strains, under which conditions, dynamic recrystallization (DRX) is expected to take place. In this study, torsion tests were carried out on a medium carbon vanadium microalloyed steel (38MnSiVS5) to simulate hot forging. Deformations were applied isothermally in the temperature range 900-1200 °C at strain rates of 0.1-10 s-1 in order to observe for the occurrence of DRX and to investigate for the microstructural evolution during straining. The shape of the flow curves indicated that the recrystallization takes place during deformation. This was supported by optical microscopy performed on the quenched samples which displayed considerable amounts of recrystallized grains. It was shown that the grain size depends on straining conditions such as strain rate and temperature. Finally, it was revealed that these process parameters can considerably affect the evolution of microstructure of industrial grade steels by means of DRX.

  1. Investigations on bending condition for welded carbon steel pipe by high frequency induction heating

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Toshimi; Matsumoto, Teruo; Tamai, Yasumasa

    1987-08-01

    The induction heating bent pipes of carbon steel welded pipes are used for the piping in nuclear power plants, in place of elbows. This application is useful to suppress the radiation exposure at in-service inspection. The quality of the bent pipes are controlled on the technical standards of welding for electrical equipments. However, the influence of the bending condition has not been yet sufficiently understood on the mechanical properties of the bent pipes. The purpose of this investigation is to establish the appropriate bending condition for the carbon steel weld pipe which corresponds to the carbon steel pipe STPT 42 in JIS G 3456, in relation to the transformation of the structures of the base metal and the weld metal during bending. The results are summarized as follows: (1) The maximum heating temperature should be set in the range from 900 deg C to 1000 deg C, in order to assure the high Charpy impact properties. (2) The maximum heating temperature which is lower than 900 deg C causes the imperfect transformation of the base metal and the weld metal, then is likely to spoil the Charpy impact properties. (3) Higher heating rate causes the increase of A/sub c1/ point, remarkably for the base metal which has higher carbon content than weld metal. (4) Higher cooling rate causes hardening of the base metal and weld metal, however, the transformation temperature does not change remarkably, except for the Ar/sub 1/ point of base metal.

  2. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-07-22

    ... party group responses to its notice of institution (75 FR 16504, April 1, 2010) were adequate. A record... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... Brazil and Japan, and the suspended investigation on hot-rolled steel from Russia. SUMMARY:...

  3. 78 FR 40429 - Certain Hot-Rolled Carbon Steel Flat Products From India: Rescission of Countervailing Duty...

    Science.gov (United States)

    2013-07-05

    ... Countervailing Duty Administrative Reviews and Request for Revocation in Part, 78 FR 6291 (January 30, 2013... Reviews and Request for Revocation in Part, 78 FR 25418, 25422 (May 1, 2013). U.S. Steel and Nucor... International Trade Administration Certain Hot-Rolled Carbon Steel Flat Products From India: Rescission...

  4. QUALITY TESTING OF HEAT TREATMENT OF MEDIUM-CARBON STEEL CONSTRUCTION ITEMS BASED ON THE BIPOLAR PULSED REMAGNETIZATION

    Directory of Open Access Journals (Sweden)

    V. F. Matyuk

    2014-01-01

    Full Text Available The features of bipolar pulsed remagnetization of construction medium-carbon steel items for testing the heat treatment temperature and structure of these items are discussed, the methods of bipolar pulse remagnetization providing testing of items of considered steels are suggested.

  5. On The Enhancement of Wear Resistance of Hardened Carbon Tool Steel (AISI 1095) With Cryogenic Quenching

    Institute of Scientific and Technical Information of China (English)

    V.Soundararajan; N.Alagurmurthi; K.Palaniradja

    2004-01-01

    Many experimental investigations reveal that it is very difficult to have a completely martensitic structure by any hardening process. Some amount of austenite is generally present in the hardened steel. This austenite existing along with martensite is normally referred as the retained austenite. The presence of retained austenite greatly reduces the mechanical properties and such steels do not develop maximum hardness even after cooling at rates higher than the critical cooling rates.Strength can be improved in hardened steels containing retained austenite by a process known as cryogenic quenching.Untransformed austenite is converted into martensite by this treatment. This conversion of retained austenite into martensite results in increased hardness, wear resistance and dimensional stability of steel. Wear can be defined as the progressive loss of materials from the operating surface of a body occurring as a result of relative motion at the surface. Hardness, load,speed, surface roughness, temperature are the major factors which influences wear. Many studies on wear indicate that increasing hardness decreases the wear of a material. With this in mind, to study the surface wear on a surface modified(Cryogenic treated) steel material an attempt has been made in this paper. In this study as a Part -I Hardening was carried out on carbon tool steel (AISI 1095) of different L/D ratio with conventional quenchants like purified water, aqueous solution and Hot mineral oil. As a Part -Ⅱ hardening was followed by quenching was carried out as said in Part- I and the hardened specimen were quenched in liquid Nitrogen which is at sub zero condition. The specimens were tested for its microstructure, hardness and wear loss. The results were compared and analyzed. The alloying elements increases the content of retained austenite hence the material used was AISI1095 (Carbon 0.9%, Si 0.2%, Mn0.4% and the rest Iron)

  6. Modelling of quenching process of medium-carbon steel

    Directory of Open Access Journals (Sweden)

    A. Kulawik

    2010-01-01

    Full Text Available The paper refers to numerical modelling of the hardening process of steel C45. In the algorithm the heat transfer equation, equilibrium equations and macroscopic model of phase transformations, basis of CCT diagrams, are used. Coupling between basic phenomena of hardening process is considered, in particular the influence of latent heat on the fields of temperature, and also thermal, structural and plastic strains and transformation - induced plasticity in the model is taken into account as well. The method of calculating the phase transformation during heating applied by the authors uses data from the continuous heating diagram (CHT. The homogenization line of austenite determines the end of heating. The influence of austenisation temperature on the kinetics of transformations is taken into account. To calculate the increase of martensite content Koistinen-Marburger formula is used. Field of stresses and strains are obtained from solutions of finite element method equations of equilibrium in increment form.

  7. Formation of carburized layer structure with reverted austenite on low-carbon martensitic steel 12Kh2G2NMFT

    Science.gov (United States)

    Ivanov, A. S.; Bogdanova, M. V.

    2013-03-01

    The structure of surface layer in low-carbon martensitic steel 12Kh2G2NMFT obtained by carburizing followed by high-temperature tempering and quenching from the intercritical temperature range is investigated.

  8. Inhibition effect of phosphorus-based chemicals on corrosion of carbon steel in secondary-treated municipal wastewater.

    Science.gov (United States)

    Shen, Zhanhui; Ren, Hongqiang; Xu, Ke; Geng, Jinju; Ding, Lili

    2013-01-01

    Secondary-treated municipal wastewater (MWW) could supply a viable alternative water resource for cooling water systems. Inorganic salts in the concentrated cooling water pose a great challenge to corrosion control chemicals. In this study, the inhibition effect of 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), trimethylene phosphonic acid (ATMP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) on corrosion of carbon steel in secondary-treated MWW was investigated by the means of potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition effect increased with increasing concentration of inhibitors. The corrosion rates of carbon steel were 1.5, 0.8, 0.2 and 0.5 mm a(-1) for blank, HEDP, ATMP and PBTCA samples at 50 mg L(-1), respectively. The phosphorus-based chemicals could adsorb onto the surface of the carbon steel electrode, form a coat of protective film and then protect the carbon steel from corrosion in the test solution.

  9. 76 FR 20954 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea..., the Department published in the Federal Register the countervailing duty order on...

  10. 77 FR 67395 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the...

    Science.gov (United States)

    2012-11-09

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the Subject Reviews AGENCY: United States International Trade Commission. ACTION: Notice. DATES:...

  11. 77 FR 16810 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-03-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea..., the Department published in the Federal Register the countervailing duty order on...

  12. 75 FR 18153 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-04-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea..., the Department published in the Federal Register the countervailing duty order on...

  13. Low-energy electron irradiation of preheated and gas-exposed single-wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ecton, P.A. [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Beatty, J.; Verbeck, G. [Department of Chemistry, University of North Texas, Denton, TX 76203 (United States); Lakshantha, W.; Rout, B. [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Perez, J.M., E-mail: jperez@unt.edu [Department of Physics, University of North Texas, Denton, TX 76203 (United States)

    2016-11-30

    Highlights: • Preheating SWCNTs in situ before irradiation prevents an increase in the D peak. • Preheated SWCNTs exposed to air or gases before irradiation show an increase in D peak. • The increase in D peak is not due to irradiation-induced chemisorption of adsorbates. • The effects are more significant for small diameter SWCNTs. • The increase in D peak is attributed to defects that increase inter-tube interactions. - Abstract: We investigate the conditions under which electron irradiation at 2 keV of single-wall carbon nanotube (SWCNT) bundles produces an increase in the Raman D peak. We find that irradiation of SWCNTs that are preheated in situ at 600 °C for 1 h in ultrahigh vacuum before irradiation does not result in an increase in the D peak. Irradiation of SWCNTs that are preheated in vacuum and then exposed to air or gases results in an increase in the D peak, suggesting that adsorbates play a role in the increase in the D peak. Small diameter SWCNTs that are not preheated or preheated and then exposed to air show a significant increase in the D and G bands after irradiation. X-ray photoelectron spectroscopy shows no chemical shifts in the C 1s peak of SWCNTs that have been irradiated versus SWCNTs that have not been irradiated, suggesting that chemisorption of adsorbates is not responsible for the increase in the D peak.

  14. Cavitation erosion resistance of diamond-like carbon coating on stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Feng; Jiang, Shuyun, E-mail: jiangshy@seu.edu.cn

    2014-02-15

    Two diamond-like carbon (DLC) coatings are prepared on stainless steel 304 by cathodic arc plasma deposition technology at different substrate bias voltages and arc currents (−200 V/80 A, labeled DLC-1, and −100 V/60 A, labeled DLC-2). Cavitation tests are performed by using a rotating-disk test rig to explore the cavitation erosion resistance of the DLC coating. The mass losses, surface morphologies, chemical compositions and the phase constituents of the specimens after cavitation tests are examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the DLC-2 coatings can elongate the incubation period of stainless steel, leading to an excellent cavitation erosion resistance as compared to the untreated stainless steel specimens. After duration of 100 h cavitation test, serious damaged surfaces and plenty of scratches can be observed on the surfaces of the stainless steel specimens, while only a few grooves and tiny pits are observed on the DLC-2 coatings. It is concluded that, decreasing micro defects and increasing adhesion can reduce the delamination of DLC coating, and the erosion continues in the stainless steel substrate after DLC coating failure, and the eroded surface of the substrate is subjected to the combined action from cavitation erosion and slurry erosion.

  15. Analyses of quenching process during turn-off of plasma electrolytic carburizing on carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jie; 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); 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); Wang, Bin; Jin, Xiaoyue; Du, Jiancheng [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)

    2014-10-15

    Highlights: • Cooling rate of carburized steel at the end of PEC treatment is measured. • The quench hardening in the fast or slow turn-off mode hardly takes place. • Decrease of the surface roughness during slow turn-off process is found. • A slow turn-off mode is recommended to replace the conventional turn-off mode. - Abstract: Plasma electrolytic carburizing (PEC) under different turn-off modes was employed to fabricate a hardening layer on carbon steel in glycerol solution without stirring at 380 V for 3 min. The quenching process in fast turn-off mode or slow turn-off mode of power supply was discussed. The temperature in the interior of steel and electron temperature in plasma discharge envelope during the quenching process were evaluated. It was found that the cooling rates of PEC samples in both turn-off modes were below 20 °C/s, because the vapor film boiling around the steel sample reduced the cooling rate greatly in terms of Leidenfrost effect. Thus the quench hardening hardly took place, though the slow turn-off mode slightly decreased the surface roughness of PEC steel. At the end of PEC treatment, the fast turn-off mode used widely at present cannot enhance the surface hardness by quench hardening, and the slow turn-off mode was recommended in order to protect the electronic devices against a large current surge.

  16. Advanced manufacturing technologies of large martensitic stainless steel castings with ultra low carbon and high cleanliness

    Directory of Open Access Journals (Sweden)

    Lou Yanchun

    2010-11-01

    Full Text Available The key manufacturing technologies associated with composition, microstructure, mechanical properties, casting quality and key process control for large martensitic stainless steel castings are involved in this paper. The achievements fully satisfied the technical requirements of the large 700 MW stainless steel hydraulic turbine runner for the Three Gorges Hydropower Station, and become the major technical support for the design and manufacture of the largest 700 MW hydraulic turbine generator unit in the world developed through our own efforts. The characteristics of a new high yield to tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel with ultra low carbon and high cleanliness are also described. Over the next ten years, the large martensitic stainless steel castings and advanced manufacturing technologies will see a huge demand in clean energy industry such as nuclear power, hydraulic power at home and abroad. Therefore, the new high yield o tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel materials, the fast and flexible manufacturing technologies of large size castings, and new environment friendly sustainable process will face new challenges and opportunities.

  17. India's iron and steel industry: Productivity, energy efficiency and carbon emissions

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Katja; Sathaye, Jayant

    1998-10-01

    Historical estimates of productivity growth in India's iron and steel sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. The authors derive both growth accounting and econometric estimates of productivity growth for this sector. Their results show that over the observed period from 1973--74 to 1993--94 productivity declined by 1.71{percent} as indicated by the Translog index. Calculations of the Kendrick and Solow indices support this finding. Using a translog specification the econometric analysis reveals that technical progress in India's iron and steel sector has been biased towards the use of energy and material, while it has been capital and labor saving. The decline in productivity was caused largely by the protective policy regarding price and distribution of iron and steel as well as by large inefficiencies in public sector integrated steel plants. Will these trends continue into the future, particularly where energy use is concerned? Most likely they will not. The authors examine the current changes in structure and energy efficiency undergoing in the sector. Their analysis shows that with the liberalization of the iron and steel sector, the industry is rapidly moving towards world-best technology, which will result in fewer carbon emissions and more efficient energy use in existing and future plants.

  18. Cavitation erosion resistance of diamond-like carbon coating on stainless steel

    Science.gov (United States)

    Cheng, Feng; Jiang, Shuyun

    2014-02-01

    Two diamond-like carbon (DLC) coatings are prepared on stainless steel 304 by cathodic arc plasma deposition technology at different substrate bias voltages and arc currents (-200 V/80 A, labeled DLC-1, and -100 V/60 A, labeled DLC-2). Cavitation tests are performed by using a rotating-disk test rig to explore the cavitation erosion resistance of the DLC coating. The mass losses, surface morphologies, chemical compositions and the phase constituents of the specimens after cavitation tests are examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the DLC-2 coatings can elongate the incubation period of stainless steel, leading to an excellent cavitation erosion resistance as compared to the untreated stainless steel specimens. After duration of 100 h cavitation test, serious damaged surfaces and plenty of scratches can be observed on the surfaces of the stainless steel specimens, while only a few grooves and tiny pits are observed on the DLC-2 coatings. It is concluded that, decreasing micro defects and increasing adhesion can reduce the delamination of DLC coating, and the erosion continues in the stainless steel substrate after DLC coating failure, and the eroded surface of the substrate is subjected to the combined action from cavitation erosion and slurry erosion.

  19. Phase Evolution in Boride-Based Cermets and Reaction Bonding onto Plain Low Carbon Steel Substrate

    Science.gov (United States)

    Palanisamy, B.; Upadhyaya, A.

    2012-04-01

    Reaction sinter bonding is a process that aims to bond two materials for improvement in properties through reactive sintering technique. The process has been effectively used to sinter hard materials like borides in situ which not only possess excellent oxidation resistance, good corrosion resistance but also resistant to abrasive wear. Sinter bonding is a unique surface modification process achieved through powder metallurgy and is competent with other techniques like boronizing sintering and sinter-brazing since it eliminates the additional operations of heat treatment and assembly and removes the inherent setbacks with these processes. This study focuses on identifying the phase evolution mechanism using characterization tools like x-ray diffractometry and energy dispersive spectroscopy and study of sinter bonding of the boron containing precursors (Mo-Cr-Fe-Ni-FeB-MoB) onto plain carbon steel. A microstructure containing Fe-based matrix dispersed with complex borides develops with temperature in the tape cast sheets. A fivefold increase in hardness between plain carbon steel in wrought condition and sinter bonded steel was observed. The multilayer consisted of a reaction zone adjacent to the interface and was investigated with the composition profile and hardness measurements. A model of sinter bonding between the cermet and the steel has also been proposed.

  20. Protection of carbon steel against hot corrosion using thermal spray Si- and Cr-base coatings

    Science.gov (United States)

    Porcayo-Calderon, J.; Gonzalez-Rodriguez, J. G.; Martinez, L.

    1998-02-01

    A Fe75Si thermal spray coating was applied on the surface of a plain carbon steel baffle plate. Beneath this coating, a Ni20Cr coating was applied to give better adherence to the silicon coating. The baffle was installed in the high-temperature, fireside, corrosion zone of a steam generator. At the same time, an uncoated 304 stainless steel baffle was installed nearby for comparison. For 13 months the boiler burned heavy fuel oil with high contents of vanadium. The samples were studied employing scanning electron microscopy, x-ray microanalysis, and x-ray diffraction techniques. After that, it was possible to inspect the structural state of the components, and it was found that the stainless steel baffle plates were destroyed almost completely by corrosion, whereas the carbon steel coated baffle plate did not suffer a significant attack, showing that the performance of the thermal spray coating was outstanding and that the coating was not attacked by vanadium salts of the molten slag.

  1. HYDROTHERMALLY SELF-ADVANCING HYBRID COATINGS FOR MITIGATING CORROSION OF CARBON STEEL.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.

    2006-11-22

    Hydrothermally self-advancing hybrid coatings were prepared by blending two starting materials, water-borne styrene acrylic latex (SAL) as the matrix and calcium aluminate cement (CAC) as the hydraulic filler, and then their usefulness was evaluated as the room temperature curable anti-corrosion coatings for carbon steel in CO{sub 2}-laden geothermal environments at 250 C. The following two major factors supported the self-improving mechanisms of the coating during its exposure in an autoclave: First was the formation of a high temperature stable polymer structure of Ca-complexed carboxylate groups containing SAL (Ca-CCG-SAL) due to hydrothermal reactions between SAL and CAC; second was the growth with continuing exposure time of crystalline calcite and boehmite phases coexisting with Ca-CCG-SAL. These two factors promoted the conversion of the porous microstructure in the non-autoclaved coating into a densified one after 7 days exposure. The densified microstructure not only considerably reduced the conductivity of corrosive ionic electrolytes through the coatings' layers, but also contributed to the excellent adherence of the coating to underlying steel' s surface that, in turn, retarded the cathodic oxygen reduction reaction at the corrosion site of steel. Such characteristics including the minimum uptake of corrosive electrolytes by the coating and the retardation of the cathodic corrosion reaction played an important role in inhibiting the corrosion of carbon steel in geothermal environments.

  2. Computation of carbon concentration curves in vacuum carburizing of steels

    Science.gov (United States)

    Semenov, M. Yu.; Smirnov, A. E.; Ryzhova, M. Yu.

    2013-05-01

    The boundary conditions of the diffusion problem in parametric form are determined on the basis of an experimental study of formation of carbon-saturated layers in vacuum carburizing. The boundary conditions are applied in a model of a process with cyclic modes of carburizing. Adequacy of the developed model is confirmed.

  3. Improved Wear Resistance of Low Carbon Steel with Plasma Melt Injection of WC Particles

    Science.gov (United States)

    Liu, Aiguo; Guo, Mianhuan; Hu, Hailong

    2010-08-01

    Surface of a low carbon steel Q235 substrate was melted by a plasma torch, and tungsten carbide (WC) particles were injected into the melt pool. WC reinforced surface metal matrix composite (MMC) was synthesized. Dry sliding wear behavior of the surface MMC was studied and compared with the substrate. The results show that dry sliding wear resistance of low carbon steel can be greatly improved by plasma melt injection of WC particles. Hardness of the surface MMC is much higher than that of the substrate. The high hardness lowers the adhesion and abrasion of the surface MMC, and also the friction coefficient of it. The oxides formed in the sliding process also help to lower the friction coefficient. In this way, the dry sliding wear resistance of the surface MMC is greatly improved.

  4. Effects of WC particle size on the wear resistance of laser surface alloyed medium carbon steel

    Science.gov (United States)

    Tong, Xin; Li, Fu-hai; Kuang, Min; Ma, Wen-you; Chen, Xing-chi; Liu, Min

    2012-01-01

    The CO2 laser surface alloying technique was used to form wear resistance layers on medium carbon steel with a kind of spherical WC powder. The effects of WC particle size on the abrasive wear resistance were thoroughly investigated. The results indicate that the laser alloyed layer is characterized by dendritic primary phase and ledeburite microstructure, consisting of austenite, martensite and carbides of Fe3W3C, W2C and WC. The laser surface alloying with WC powder could improve the abrasive wear resistance of the medium carbon steel by over 63%. The factors such as the hardness, the amount and the distribution of WC particle determined the laser alloyed samples' wear resistance, and the laser alloyed sample with WC powder of 88-100 μm diameter presented the best wear resistance in this study. Furthermore, the wear resistance mechanisms of the laser alloyed layers were also explored.

  5. Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available Linear alkyl benzene sulfonic acid (L and three of its ester derivatives (L1, L2, L3 were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q. The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH∗, entropy (ΔS∗ of activation, adsorption–desorption equilibrium constant (Kads, standard free energy of adsorption (ΔGoads, heat (ΔHoads, and entropy of adsorption (ΔSoads were calculated to elaborate the corrosion inhibition mechanism.

  6. Carbon recovery by fermentation of CO-rich off gases - Turning steel mills into biorefineries.

    Science.gov (United States)

    Molitor, Bastian; Richter, Hanno; Martin, Michael E; Jensen, Rasmus O; Juminaga, Alex; Mihalcea, Christophe; Angenent, Largus T

    2016-09-01

    Technological solutions to reduce greenhouse gas (GHG) emissions from anthropogenic sources are required. Heavy industrial processes, such as steel making, contribute considerably to GHG emissions. Fermentation of carbon monoxide (CO)-rich off gases with wild-type acetogenic bacteria can be used to produce ethanol, acetate, and 2,3-butanediol, thereby, reducing the carbon footprint of heavy industries. Here, the processes for the production of ethanol from CO-rich off gases are discussed and a perspective on further routes towards an integrated biorefinery at a steel mill is given. Recent achievements in genetic engineering as well as integration of other biotechnology platforms to increase the product portfolio are summarized. Already, yields have been increased and the portfolio of products broadened. To develop a commercially viable process, however, the extraction from dilute product streams is a critical step and alternatives to distillation are discussed. Finally, another critical step is waste(water) treatment with the possibility to recover resources.

  7. Fatigue life of stainless steel 304 enhancement by addition of multi-walled carbon nanotubes (MWCNTs)

    Energy Technology Data Exchange (ETDEWEB)

    Syed, Rizwanulhaque; Jiang, Wei; Wang, Cunshan [Dalian University of Technology, Dalian (China); Sabir, M. Iqbal [Xiao Zhang County, Tianjin (China)

    2015-01-15

    Stainless steel is among the most widely used industrial materials. In particular, stainless steel 304 (304SS) is the most used material grade. To increase the utilization of any industrial material, its fatigue life should be optimized. In this work, the fatigue life of 304SS was enhanced by the addition of multi-walled carbon nanotubes (MWCNTs). Moreover, the incorporation of a small amount of MWCNTs increased the fatigue life of 304SS. Scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction (XRD) results showed that the suppression of fatigue crack growth rate was caused by CNT deposition at the crack tip. CNTs were entangled with each other, thereby resulting in finer grain size. The XRD diffractograms of the 304SS treated area peak showed that the microstructure consisted of austenite and carbon.

  8. Using Phased Array Ultrasonic Testing in Lieu of Radiography for Acceptance of Carbon Steel Piping Welds

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Traci L.; Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Nove, Carol A.

    2014-08-01

    The Pacific Northwest National Laboratory (PNNL) is conducting studies for the U.S. Nuclear Regulatory Commission (NRC) to assess the capability, effectiveness, and reliability of ultrasonic testing (UT) as a replacement method for radiographic testing (RT) for volumetric examination of nuclear power plant (NPP) components. This particular study focused on evaluating the use of UT on carbon steel plate welds. Welding fabrication flaws included a combination of planar and volumetric types, e.g., incomplete fusion, lack of penetration, cracks, porosity, and slag inclusions. The examinations were conducted using phased-array (PA) UT techniques applied primarily for detection and flaw type characterization. This paper will discuss the results of using UT in lieu of RT for detection and classification of fabrication flaws in carbon steel plate welds.

  9. Modeling of Reversible γ/α Transformations of Low Carbon Steels in the Intercritical Temperature Range

    Institute of Scientific and Technical Information of China (English)

    Tam(a)s R(E)TI; Imre FELDE; Hakan G(U)R

    2004-01-01

    A phenomenological kinetic model has been developed for the prediction of non-isothermal reversible incomplete transformations in low-carbon hypoeutectoid steels. The theoretical basis of the proposed method has its origin in a possible extension of the traditional Austin-Rickett kinetic differential equation. To critically assess the applicability of the model, anumber of experiments based on computer simulations have been performed to predict the austenite/ferrite proeutectoid transformation in the temperature range of Ae1 to Ae3 on plain carbon hypoeutectoid steels. A comparison with published experimental data has verified that the model developed is reasonable both quantitatively and with respect to well-established trends. Extension of the method of prediction appears promising when the non-isothermal reactions occurring during heat treatment (such as carbide precipitation and dissolution) can be assumed to proceed in a reversible manner.

  10. Bonding strength in carbon steel sandwich panels under condition of diffusion-rolling with small reduction

    Institute of Scientific and Technical Information of China (English)

    LIU Jing; HAN Jing-tao; FU Ding-mei

    2005-01-01

    One of the key problems by diffusion-rolling bonding with small reduction for carbon steel plates is the bonding assistant coat. A bonding assistant coat used below 850 ℃ was developed. It contained copper as basic element and zinc as main alloy element. Other small elements and rare metals were added to decrease the melting point and to obtain a better clouding and high plasticity. Based on the theory of brazing and transient liquid diffusion welding, two carbon steel plates were rolled with small reduction by using self-made bonding assistant coat. Temperature, pressure and holding time are the main technology parameters for controlling the process of diffusion-rolling. The results show that the bonding strength is the greatest when the bonding temperature is 830 ℃, holding time is 3 min and the reduction rate is 9%.

  11. Effect of Carbon and Nitrogen Content on Deformation and Fracture of AISI 304 Austenitic Stainless Steel

    Directory of Open Access Journals (Sweden)

    C. Menapace

    2008-04-01

    Full Text Available The effect of small differences in the content of carbon and nitrogen on the room temperature tensile deformation and fracture behaviour of an AISI 304 stainless steel was studied. In the steel containing the lower amount of carbon and nitrogen, a higher amount of strain induced alfa’ martensite is formed, which increases strain hardening rate and both uniform and total elongation at fracture. The presence of large martensitic areas in the cross section causes strain localization at the austenite/martensite interface, which promotes the nucleation of cracks and their propagation along the interface. This results in a decrease of Ultimate Tensile Strength. Strain induced transformation slightly reduces strain rate sensitivity, as well.

  12. Green corrosion inhibitors for carbon steel by green leafy vegetables extracts in 1 M HCl

    Directory of Open Access Journals (Sweden)

    Ghadah M. Al-Senani

    2015-12-01

    Full Text Available The effect of some Green Leafy Vegetables (GLV extracts namely Lactuca sativa (Lactuca, Eruca Sativa (Arugula, Petroselinum crispum (Parsley, and Anethum Graveolens (Dill were investigated on inhibition of corrosion carbon steel in 1 M HCl solution using gravimetric (weight loss method. The inhibition efficiency has increased as concentration of the extract increased. The inhibition efficiency has decreased as the temperature increased. The results obtained showed that GLV extracts inhibited the corrosion process by a physical adsorption mechanism that followed the Langmuir, Freundlich, and Temkin adsorption isotherm models. The adsorption thermodynamic parameters that were calculated include, free energy of adsorption (∆G°ads, activation energy (Ea, enthalpy of adsorption (ΔH°ads, and entropy of adsorption (ΔS°ads are proposed for the corrosion of carbon steel in 1 M HCl in the absence and presence of GLV extract.

  13. Effect of Caffeine-Zn2+ System in Preventing Corrosion of Carbon Steel in Well Water

    Directory of Open Access Journals (Sweden)

    K. Rajam

    2013-01-01

    Full Text Available The inhibition efficiency (IE of caffeine in controlling corrosion of carbon steel in well water in the absence and presence of Zn2+ has been evaluated by mass loss method. The formulation, consisting of 200 ppm of caffeine and 50 ppm Zn2+, offers 82% inhibition efficiency to carbon steel immersed in well water. Addition of malic acid increases inhibition efficiency of the caffeine-Zn2+ system. The inhibition efficiency of caffeine-Zn2+ and caffeine-Zn2+-malic acid system decreases with the increase in immersion period and increases with the increase in pH from 3 to 11. AC impedance spectra, SEM micrographs, and AFM studies reveal the formation of protective film on the metal surface. The film is found to be UV fluorescent.

  14. Formation of TiO2 Modified Film on Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Laizhou SONG; Shizhe SONG; Zhiming GAO

    2004-01-01

    A new technique for preparing TiO2 modified film on carbon steel was accomplished by electroless plating and sol-gel composite process. The artificial neural network was applied to optimize the preparing condition of TiO2 modified film. The optimized condition for forming TiO2 modified film on carbon steel was that NiP plating for 50 min,dip-coating times as 4, heat treatment time for 2 h, and the molar ratio of complexing agent and Ti(OC4HZ9)4 kept 1.5:1. The results showed that TiO2 modified film have good corrosion resistance. The result conformed that it is feasible to design the preparing conditions of TiO2 modified film by artificial neural network.

  15. Contribution of electrochemical dissolution during pickling of low carbon steel in acidic solutions

    OpenAIRE

    2014-01-01

    International audience; An electrochemical cell coupled with ICP-OES chemical analysis was used to explore the role of chemical and electrochemical reactions in pickling of low carbon steel in acidic media. Impedance spectroscopy was used to highlight scale properties. Dissolution of hematite is shown to be mainly of chemical nature, whereas the dissolution of magnetite and wüstite is both chemical and electrochemical. Initially, chemical dissolution of the scale dominated. The electrochemica...

  16. Use of Artificial Neural Network for Predicting the Mechanical Property of Low Carbon Steel

    OpenAIRE

    Somkuwar, Vandana

    2013-01-01

    For product development manufacturers and designers need information about the existing materials and new material and its properties as early as possible. This paper presents a method of predicting the properties of unknown material using artificial neural network. The developed neural network model is employed for simulations of the relationship between mechanical property and the chemical composition of low carbon steel. Simulating and analyzing result shows that network model can effectiv...

  17. Kinetics of austenite formation during continuous heating in a low carbon steel

    OpenAIRE

    Oliveira, Fernando Lucas Gonçalves e; Andrade, Margareth Spangler; Cota, André Barros

    2007-01-01

    The kinetics and microstructural evolution of austenite formation in a low carbon steel, with initial microstructure composed of ferrite and pearlite, were studied during continuous heating, by using dilatometric analysis and measurements of microstructural parameters. The formation of austenite was observed to occur in two stages: (a) pearlite dissolution and (b) ferrite to austenite transformation. The critical temperatures of austenite formation in continuous heating increase with increasi...

  18. Multi-objective Optimization of Process Performances when Cutting Carbon Steel with Abrasive Water Jet

    Directory of Open Access Journals (Sweden)

    M. Radovanović

    2016-12-01

    Full Text Available Multi-objective optimization of process performances (perpendicularity deviation, surface roughness and productivity when cutting carbon steel EN S235 with abrasive water jet is presented in this paper. Cutting factors (abrasive flow rate, traverse rate and standoff distance were determined when perpendicularity deviation and surface roughness are minimal and productivity is maximal. Multi-objective genetic algorithm (MOGA was used for the determination set of nondominated optimal points, known as Pareto front.

  19. CO{sub 2} corrosion resistance of carbon steel in relation with microstructure changes

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa, Nathalie, E-mail: nochoa@usb.ve [Departamento de Ciencia de los Materiales, Universidad Simón Bolívar, Aptdo., 89000, Caracas (Venezuela, Bolivarian Republic of); Vega, Carlos [Departamento de Ciencia de los Materiales, Universidad Simón Bolívar, Aptdo., 89000, Caracas (Venezuela, Bolivarian Republic of); Pébère, Nadine; Lacaze, Jacques [Université de Toulouse, CIRIMAT, UPS/INPT/CNRS, ENSIACET, 4 Allée Emile Monso, CS 44362, 31030 Toulouse Cedex 4 (France); Brito, Joaquín L. [Laboratorio de Físico-química de Superficies, Centro de Química, Instituto Venezolano de Investigaciones Cientificas (IVIC), Carretera Panamericana, Km 11, Altos de Pipe, Estado Miranda (Venezuela, Bolivarian Republic of)

    2015-04-15

    The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO{sub 2} was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to characterize the formation of the corrosion product layers. Electrochemical results revealed that corrosion resistance increased in the following order: B < N < Q&T < A. From the polarization curves it was shown that specifically, cathodic current densities were affected by microstructural changes. SEM images indicated that ferrite dissolved earlier than cementite and a thin layer of corrosion products was deposited on the steel surface. XPS analyses revealed that this layer was composed of a mixture of iron carbonate and non-dissolved cementite. It was also found that the quantity of FeCO{sub 3} content on the steel surface was greater for Q&T and A microstructures. These results, in agreement with the electrochemical data, indicate that the deposition mechanism of iron carbonate is closely related to the morphology of the non-dissolved cementite, determining the protective properties of the corrosion product layers. - Highlights: • The effect of change in microstructure on CO{sub 2} corrosion resistance was evaluated. • An API 5LX 42 carbon steel was immersed in a 0.5 M NaCl solution saturated with CO{sub 2}. • Banded, normalized, quenched-tempered and annealed microstructures were considered. • Electrochemical measurements were coupled with surface analysis. • Morphology and distribution of undissolved Fe{sub 3}C control corrosion kinetics.

  20. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Energy Technology Data Exchange (ETDEWEB)

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  1. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  2. Surface coatings on carbon steel for prevention of flow accelerated corrosion under two phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hee-Sang; Kim, Kyung Mo; Hur, Do Haeng [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Seung Hyun; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    Since the occurrence of a Surry-2 pipe rupture accident, a lot of effort has been made to prevent FAC of carbon steel piping. Some of the chemicals were suggested as a corrosion inhibitor. A platinum decoration was applied as another prevention strategy of carbon steel thinning. The severe FAC-damaged carbon steel pipings were replaced by tolerant materials such as SA335 Gr.P22. However, some components such as the piping materials between moisture separator and turbine have still suffered from the FAC degradation. This work provides a coating method to prevent the FAC degradation of the SA106 Gr.B, which is a piping material between moisture separator and high-pressure turbine, under two-phase flow. We suggested the coating materials to prevent FAC of SA106Gr.B under two-phase water-vapor flow. The FAC resistance of SA106Gr.B was improved with 5 times by electroless-deposited Ni-P protective layer. Other coating materials also enhanced the tolerance up to 5 times for the FAC in a condition of 150 .deg. C and 3.8 bar at 9.5 compared to non-coated SA106Gr.B.

  3. Formation of Diffusion Layers by Anode Plasma Electrolytic Nitrocarburizing of Low-Carbon Steel

    Science.gov (United States)

    Kusmanov, S. A.; Kusmanova, Yu. V.; Naumov, A. R.; Belkin, P. N.

    2015-08-01

    The structure of the low-carbon steel after plasma electrolytic nitrocarburizing in the electrolyte containing acetonitrile was investigated. The cross-sectional microstructure, composition, and phase constituents of a modified layer under different processing conditions were characterized. It is shown that the electrolyte that contained ammonium chloride and acetonitrile provides the saturation of steel with nitrogen and carbon and the formation of the Fe4N and FeN0.05 nitrides, Fe4C carbide and other phases. The nitrogen diffusion decreases the austenitization temperature and results in the formation of martensite after the sample cooling in the electrolyte. The formation of a carbon and nitrogen source in a vapor-gas envelope (VGE) is investigated. The proposed mechanism includes evaporation of acetonitrile in the VGE, its adsorption on an anode with the following thermal decomposition, and also the acetonitrile reduction to amine with subsequent hydrolysis to ethanol that is determined with the use of chromatographic method. The aqueous solution that contained 10 wt.% NH4Cl and 10 wt.% CH3CN allows one to obtain the nitrocarburized layer with the thickness of 0.22 mm and microhardness up to 740 HV during 10 min at 850 °C. This treatment regime leads to the decrease in the surface roughness of steel R a from 1.01 μm to 0.17 μm.

  4. Growth characteristics of thermophile sulfate-reducing bacteria and its effect on carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T.; Liu, H.; Hu, Y.; Zhou, L.; Zheng, B. [Department of Chemistry and Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2009-03-15

    Sulfate-reducing bacteria (SRB) have been identified as the main corrosive microorganisms causing unpredictable failure of materials. In this present work, a strain of thermophile SRB isolated from Bohai oilfield of China has been characterized and preliminarily identified. Furthermore, its effects on carbon steel at 60 C in SRB culture media were studied by electrochemical methods such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), and weight loss measurements. The results show that the bacteria belong to Desulfotomaculum. The optimum growth temperature and pH of the bacteria were 60 C and 7.0, respectively. Weight loss measurements suggested that the corrosion rate of carbon steel in the culture media inoculated with thermophile SRB at 60 C was 2.2 times less than that at 37 C. At 60 C, SRB shifted the freely corroding potential of carbon steel toward a more positive value in the first 10 days, which later change to a negative value. Results obtained from potentiodynamic polarization and EIS were in good agreement. The changes in biofilm structure with increase in bacteria supply offers some kind of protection to the base material in the early culture days at 60 C. Subsequently, it accelerated corrosion. Energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) methods indicate that corrosion products such as iron sulfides (FeS{sub x}) in biofilm play an important role in the biocorrosion process. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  5. A Novel Carbon Steel Pipe Protection Based on Radial Basis Function Neural Network

    Directory of Open Access Journals (Sweden)

    Sami A. Ajeel

    2010-01-01

    Full Text Available Problem statement: The cost due to corrosion Damage have estimated to be 3-4% of their gross national product which significantly Countries problem around the world. Approach: In this study, a novel carbon steel pipe protection based on RBFNN was proposed. The RBFNN used to predict the minimum current density required in impressed current cathodic protection to protect low carbon steel pipe. Learning data was performed by using a 30 samples test with different concentration C%, temperature T, distance D and pH. The RBFNN model has four input nodes representing the (concentration C%, temperature T, distance D and pH, eight nodes at hidden layer and one output node representing the min. current density. Results: Generalization test used 5 data samples taken from the experimental results other than those data samples used in the learning process to check the performance of the neural network on these data. Conclusion: In addition, the experimental results indicate that proposed system can be used successfully to obtain minimum cathodic protection current density to protect low carbon steel pipes.

  6. Seed Extract of Psidium guajava as Ecofriendly Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Medium

    Institute of Scientific and Technical Information of China (English)

    K.P.Vinod Kumar; M. Sankara Narayana Pillai; G. Rexin Thusnavis

    2011-01-01

    The anticorrosion characteristics of the seeds of Psidium guajava (P. Guajava) fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of adsorption of the inhibitor on the metal surface (Q), change in entropy (△S), change in free energy of the reaction (△G), corrosion rate (CR) and energy of activation for corrosion reaction of carbon steel (E) were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investigated using Fourier transform infrared (FT-IR) spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy (SEM) micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. Guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.

  7. Fate of D3 mouse embryonic stem cells exposed to X-rays or carbon ions.

    Science.gov (United States)

    Luft, S; Pignalosa, D; Nasonova, E; Arrizabalaga, O; Helm, A; Durante, M; Ritter, S

    2014-01-15

    The risk of radiation exposure during embryonic development is still a major problem in radiotoxicology. In this study we investigated the response of the murine embryonic stem cell (mESC) line D3 to two radiation qualities: sparsely ionizing X-rays and densely ionizing carbon ions. We analyzed clonogenic cell survival, proliferation, induction of chromosome aberrations as well as the capability of cells to differentiate to beating cardiomyocytes up to 3 days after exposure. Our results show that, for all endpoints investigated, carbon ions are more effective than X-rays at the same radiation dose. Additionally, in long term studies (≥8 days post-irradiation) chromosomal damage and the pluripotency state were investigated. These studies reveal that pluripotency markers are present in the progeny of cells surviving the exposure to both radiation types. However, only in the progeny of X-ray exposed cells the aberration frequency was comparable to that of the control population, while the progeny of carbon ion irradiated cells harbored significantly more aberrations than the control, generally translocations. We conclude that cells surviving the radiation exposure maintain pluripotency but may carry stable chromosomal rearrangements after densely ionizing radiation.

  8. Graphitization of Spray-formed Ultrahigh Carbon Steels Containing Si during Hot Rolling

    Institute of Scientific and Technical Information of China (English)

    Guangmin LUO; Jiansheng WU; Junfei FAN; Haisheng SHI; Yijian LIN; Jingguo ZHANG

    2005-01-01

    The graphitization behavior of ultrahigh carbon steels containing Si in hot rolling processes was investigated. The graphite stringers went mostly through the small pores and generally paralleled to the rolling direction. The influence of alloy elements on graphitization was estimated based on thermodynamics, which showed that Si content was important for graphitization. Graphite stringers nucleated at small pores and grew with carbon diffusion during hot rolling. Alloy contents, pores and hot deformation at γ+Fe3C phase range were the key factors for the formation of graphite. The probable effect of deformation on graphite formation during hot rolling was discussed in this paper.

  9. Growth of carbon nanotubes and microfibers over stainless steel mesh by cracking of methane

    OpenAIRE

    2008-01-01

    The ${La}_{2}{NiO}_{4}$ film was synthesized on the 304 stainless steel (SS) mesh. The hydrogen reduction of La2NiO4 generated homogeneous nanocatalyst particles (probably ${Ni}/{La}_2{O}_{3}$) over which methane was cracked, producing carbon notubes/microfibers and hydrogen. The carbon nanotubes/microfibers were strongly bonded to the SS mesh. It was observed that the methane conversion always reached its maximum at the cracking temperature of 750 °C regardless of its concentration varying f...

  10. Effect of RE-Modifier on Microstructure and Mechanical Property of High-Carbon Medium-Manganese Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of RE-modifier on the microstructure and mechanical properties of high carbon-medium manganese steel has been investigated in present work. The results showed that the RE-modifier can refine the crystalline grain of high-carbon medium-manganese steel. The shape and distribution of carbides are improved and the columnar grains and phosphide in grain boundary are eliminated. Consequently, the impact toughness of the steel is increased by more than one time, compared with no addition of RE-modifier.

  11. Mathematical Modeling and Microstructure Analysis of Low Carbon Steel Strips Produced by Horizontal Single Belt Casting (HSBC)

    Science.gov (United States)

    Ge, Sa; Chang, Sheng; Wang, Tong; Calzado, Luis E.; Isac, Mihaiela; Kozinski, Janusz; Guthrie, Roderick I. L.

    2016-06-01

    The horizontal single belt casting (HSBC) process has been proposed as an efficient, economical, and environmentally friendly alternative approach to the production of ferrous alloys. Low carbon steel strips were cast using the HSBC simulator apparatus to study the characteristics and properties of the as-cast steel strips. Three-dimensional computational fluid dynamics simulations using ANSYS FLUENT 14.5 were also performed. Numerical predictions were validated against experimental casting results. Microstructural analyses and as-cast surface texture studies were conducted on low carbon steels.

  12. Adsorption and corrosion-inhibiting effect of Dacryodis edulis extract on low-carbon-steel corrosion in acidic media.

    Science.gov (United States)

    Oguzie, E E; Enenebeaku, C K; Akalezi, C O; Okoro, S C; Ayuk, A A; Ejike, E N

    2010-09-01

    The inhibition of low-carbon-steel corrosion in 1M HCl and 0.5M H(2)SO(4) by extracts of Dacryodis edulis (DE) was investigated using gravimetric and electrochemical techniques. DE extract was found to inhibit the uniform and localized corrosion of carbon steel in the acidic media, affecting both the cathodic and anodic partial reactions. The corrosion process was inhibited by adsorption of the extracted organic matter onto the steel surface in a concentration-dependent manner and involved both protonated and molecular species. Molecular dynamics simulations were performed to illustrate the process of adsorption of some specific components of the extract.

  13. Effect of heat treatment on the wear resistance of high-carbon and high-nitrogen steels subjected to abrasive wear

    Science.gov (United States)

    Filippov, M. A.; Belozerova, T. A.; Blinov, V. M.; Kostina, M. A.; Val'kov, E. V.

    2006-03-01

    The effect of quenching and tempering on the capacity of steels based on chromium-carbon, chromium-nitrogen, and carbon-manganese austenite for strain-induced martensitic transformation, hardening, and wear resistance in the process of abrasive wear is studied. The steels contain 1-1.2% C or N and 18% Cr or Mn. The wear resistance of the studied steels having a structure of metastable austenite is compared to that of steel 110G13.

  14. 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

  15. Fatigue testing of steel pipes repaired with carbon/epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Jeffrey M.; Kessler, Michael R. [University of Tulsa, OK (United States). Dept. of Mechanical Engineering; Walker, Roger H.; Duell, Joshua M. [Citadel Technologies (CTI Services LLC), Tulsa, OK (United States); Kadakia, Dixit; Sousa, Nuno [T.D. Williamson, Inc., Tulsa, OK (United States)

    2005-07-01

    Fatigue tests were performed on pressure vessels to determine the effectiveness of repairs made using a carbon/epoxy composite material system. The carbon/epoxy system is intended to repair externally damaged or corroded steel pipe where blunt defects are present. 6.0 inch (15.2 cm) nominal diameter by 5.0 feet (1.52 m) long pressure vessels were constructed from A-106 Grade B steel for test purposes. Defects were machined into the outer surface of each vessel to determine limitations of the carbon/epoxy repair system. Two test plans were used in this work. The vessels of the first test plan contained relatively sharp defects and were subjected to internal pressure fluctuations between 13 and 113% of MAOP. The vessels of the second test plan contained more blunt-like defects and were cyclically pressurized from 55 to 100% of the pipe MAOP. Results indicate there is substantial increase in the performance of pipes repaired with the carbon/epoxy composite compared to those with no repairs. At the conclusion of the cyclical pressurization, the pipes with the carbon/epoxy repair were pressurized monotonically until rupture occurred. From the second test plan, the monotonic rupture data after fatigue showed no degradation in failure pressures compared with rupture data of non-fatigued vessels. (author)

  16. The time-dependent health and biochemical effects in rats exposed to stainless steel welding dust and its soluble form.

    Science.gov (United States)

    Halatek, Tadeusz; Stanislawska, Magdalena; Kaminska, Irena; Cieslak, Malgorzata; Swiercz, Radoslaw; Wasowicz, Wojciech

    2017-02-23

    Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. The principal objective of this study was to determine the dynamics of toxic effects of inhalation exposure to morphologically rated welding dust from stainless steel welding and its soluble form in TSE System with a dynamic airflow. We assessed the pulmonary toxicity of welding dust in Wistar rats exposed to 60.0 mg/m(3) of respirable-size welding dust (mean diameter 1.17 µm) for 2 weeks (6 h/day, 5 days/week); the aerosols were generated in the nose-only exposure chambers (NOEC). An additional aim included the study of the effect of betaine supplementation on oxidative deterioration in rat lung during 2 weeks of exposure to welding dust or water-soluble dust form. The animals were divided into eight groups (n = 8 per group): control, dust, betaine, betaine + dust, soluble-form dust, soluble-form dust + betaine, saline and saline + betaine groups. Rats were euthanized 1 or 2 weeks after the last exposure for assessment of pulmonary toxicity. Differential cell counts, total protein concentrations and cellular enzyme (lactate dehydrogenase-LDH) activities were determined in bronchoalveolar lavage (BAL) fluid, and corticosterone and thiobarbituric acid reactive substances (TBARS) concentrations were assessed in serum. The increase in polymorphonuclear (PMN) leukocytes in BAL fluid (a cytological index of inflammatory responses of the lung) is believed to reflect pulmonary toxicity of heavy metals. Biomarkers of toxicity assessed in bronchoalveolar fluids indicate that the level of the toxic effect depends mainly on the solubility of studied metal compounds; biomarkers that showed treatment effects included: total cell, neutrophil and lymphocyte counts, total protein concentrations, and cellular enzyme (lactate dehydrogenase) activity

  17. Outbursts formation on low carbon and trip steel grades during hot-dip galvanisation

    Science.gov (United States)

    Petit, E. J.; Lamm, L.; Gilles, M.

    2004-12-01

    Low carbon and TRIP grade steels have been hot dip galvanised in order to study outbursts formation. Microstructure and texture of intermetallic phases have been observed after selective electrochemical etching by scanning electron microscopy. Potential versus time (chronopotentiometric) characteristics were recorded in order to monitor surface modifications. This combination of techniques enable to quantify and observe intermetallic phase one by one. The overall thickness of coating on both substrates are similar. However, microstructures of Fe-Zn intermetallic phases are very different on both grades. In particular, the V phase is dense on standard steel but develops a highly branched filament structure on TRIP steel. The transformation of V phase to d and G1 are limited on TRIP steel. Differences of texture provide clues for understanding mechanisms of formation of outbursts. They can account for the differences of mechanical properties and corrosion resistance. Silicon from the substrate influences the reactivity of TRIP steels due to capping and local reactions. La formation des outbursts a été étudiée sur un acier bas carbone et sur un acier TRIP galvanisés. Les épaisseurs des revêtements sont similaires. Néanmoins, les observations microscopiques et les érosions électrochimiques montrent que la répartition des phases intermétalliques et leurs microstructures diffèrent sensiblement en fonction de la nature du substrat. Ces différences expliquent les propriétés mécaniques et anticorrosions. L’encapsulation de la surface par les oxydes de silicium freine la transformation de la phase dzêta en delta et gamma sur l’acier TRIP.

  18. Electrochemical evaluation of the corrosion behaviour for structural steel SAE 1005 exposed to two different atmospheres (urban and industrial) and comparison with atmospheric corrosion gravimetric measurements

    Science.gov (United States)

    Salas, Y.; Guerrero, L.; Castiblanco, H.; Torres, C.; Palacios, A.

    2016-02-01

    The Atmospheric corrosion is a phenomenon we see every day in our environment that arises due to environmental pollution we generate, there is currently very little information on atmospheric corrosion in the department of Boyacá and in general, in Colombia. The aim of this paper is to analyse which of these two environments is more aggressive and wherein the steel corrodes faster. To analyse these phenomenon specimens made in steel SAE 105 exposed for five months to the atmosphere in the municipalities of Tunja and Nobsa (an urban atmosphere and other industrial atmosphere) were installed, a control was carried to verify the amount of time that will be exposed each of these samples to the atmosphere, of Thus it may determine the lifetime of a structural steel. For the analysis of these samples electrochemical tests were carried out to calculate the rate of corrosion and resistance to polarization, also the gravimetric method be conducted to compare what was the amount of mass lost during the time of exposure to each of the samples.

  19. Nanosecond pulsed laser welding of high carbon steels

    Science.gov (United States)

    Ascari, Alessandro; Fortunato, Alessandro

    2014-03-01

    The present paper deals with the possibility to exploit low-cost, near infra-red, nanosecond pulsed laser sources in welding of high carbon content thin sheets. The exploitation of these very common sources allows to achieve sound weld beads with a good depth-to-width ratio and very small heat affected zones when the proper process parameters are involved. In particular the role of pulse frequency, pulse duration, peak power and welding speed on the characteristics of the weld beads is studied and the advantage of the application of short-pulse laser sources over traditional long-pulse or continuous wave one is assessed.

  20. Coarsening behaviour of M23C6 carbides in creep-resistant steel exposed to high temperatures

    OpenAIRE

    M. Godec; Skobir Balantič, D. A.

    2016-01-01

    High operating temperatures can have very deleterious effects on the long-term performance of high-Cr, creep-resistant steels used, for example, in the structural components of power plants. For the popular creep-resistant steel X20CrMoV12.1 we analysed the processes of carbide growth using a variety of analytical techniques: transmission electron microscopy (TEM) and diffraction (TED), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The evolution of the micro...

  1. Influence of formulated neem seed oil and jatropha curcas seed oil on wire drawing of mild steel and medium carbon steel at elevated temperatures

    Directory of Open Access Journals (Sweden)

    Mamuda Muhammad

    2016-09-01

    Full Text Available So many facets of hot wire drawing process, despite its extensive and long time employment in the industries, still remain unclear, due to want of systematic investigation of the process. This work investigated the influence of formulated neem seed and jatropha seed oil as lubricants, using antimony dialkyl dithiocarbamates (ADTC as an additive, on wire drawing process. The suitability of the bio-based oils in friction and wear control during wire drawing process were investigated, using a four ball tester. Experimental drawing process, using a Tungsten Carbide die and the formulated lubricants was carried out on mild steel and medium carbon steel rod (6 and 8mm diameter respectively at temperatures from 20OC to 750OC, on a drawing bench. The stresses and the temperature distribution profiles along the work-piece were reported. Up to 45% of reductions in area, without wire fracture, achieved on the drawing of the medium carbon steel have equally been reported.

  2. Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale.

    Science.gov (United States)

    Hossain, R; Pahlevani, F; Quadir, M Z; Sahajwalla, V

    2016-10-11

    Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels' performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano scale of the compressive stability of retained austenite in high carbon martensitic steel. Using a combination of standard compression testing, X-ray diffraction, optical microstructure, electron backscattering diffraction imaging, electron probe micro-analysis, nano-indentation and micro-indentation measurements, we determined the mechanical stability of retained austenite and martensite in high carbon steel under compressive stress and identified the phase transformation mechanism, from the macro to the nano level. We found at the early stage of plastic deformation hexagonal close-packed (HCP) martensite formation dominates, while higher compression loads trigger body-centred tetragonal (BCT) martensite formation. The combination of this phase transformation and strain hardening led to an increase in the hardness of high carbon steel of around 30%. This comprehensive characterisation of stress induced phase transformation could enable the precise control of the microstructures of high carbon martensitic steels, and hence their properties.

  3. Equilibration of plain carbon and alloy steels with endothermic carburizing atmospheres: Part II. Oxidation of plain carbon and Armco steels during carburizing at 1000 °C and 1038 °C

    Science.gov (United States)

    Hwang, Jong-Il; Jhee, Tae-Gu; Kim, Young-Kyu; Hwang, Tae-Young

    2010-10-01

    Carbon contents by the weight gain of AISI type 1010 steel foils equilibrated with CO-CO2 mixtures at 1000 °C were 0.03 wt.% to 0.07 wt.% higher than those by chemical analysis at carbon potentials of 0.2 wt.%C to 0.7 wt.%C. The lower the carbon potential, the bigger the difference became. This difference of 0.05 wt.% to 0.08 wt.% was also measured when the same materials were equilibrated with CO-CO2 mixtures at 1038 °C at carbon potentials below 0.4 wt.%C. Oxygen analyses of these equilibrated steel foils confirmed that those differences of 0.03 wt.% to 0.07 wt.% and 0.05 wt.% to 0.08 wt.% were mainly due to the selective oxidation of manganese. When Armco steels and type 1010 steels were equilibrated simultaneously with endothermic-base carburizing atmospheres at 1038 °C, oxidation was negligible and the carbon contents of the both steels were identical at carbon potentials of 0.2 wt.%C to 1.4 wt.%C.

  4. Low-energy electron irradiation of preheated and gas-exposed single-wall carbon nanotubes

    Science.gov (United States)

    Ecton, P. A.; Beatty, J.; Verbeck, G.; Lakshantha, W.; Rout, B.; Perez, J. M.

    2016-11-01

    We investigate the conditions under which electron irradiation at 2 keV of single-wall carbon nanotube (SWCNT) bundles produces an increase in the Raman D peak. We find that irradiation of SWCNTs that are preheated in situ at 600 °C for 1 h in ultrahigh vacuum before irradiation does not result in an increase in the D peak. Irradiation of SWCNTs that are preheated in vacuum and then exposed to air or gases results in an increase in the D peak, suggesting that adsorbates play a role in the increase in the D peak. Small diameter SWCNTs that are not preheated or preheated and then exposed to air show a significant increase in the D and G bands after irradiation. X-ray photoelectron spectroscopy shows no chemical shifts in the C 1s peak of SWCNTs that have been irradiated versus SWCNTs that have not been irradiated, suggesting that chemisorption of adsorbates is not responsible for the increase in the D peak.

  5. Application of carbon FRP for fatigue strengthening of old steel structures

    Science.gov (United States)

    Vůjtěch, J.; Ryjáček, P.; Vovesný, M.

    2017-02-01

    The traffic requirements on the existing infrastructure are rising still. This coupled with its age puts a strain on it. This is especially problematic for old steel bridges. Higher and more frequent loads will lead to development of fatigue damage to those structures. This causes an issue for the infrastructure owners as the existing methods of repair are difficult, time consuming and expensive. So there is a need to find some easier alternatives. One of such can be the use of carbon fibre reinforced polymers (CFRP). They are being successfully used for repairs and strengthening of concrete structures however their use with steel is still relatively new. The purpose of this work is to establish how does a deteriorated steel reinforced with CFRP behave under fatigue loading. To test this a series of experiments was designed. With the help of a preliminary numerical study the dimensions of the specimens and the applied loading was established. There are two sets of specimens. With both we are using mild steel and each set has different level of surface deterioration (corrosion pits or corrosion holes). The specimens are reinforced using hand laid wet layup composites. They are subjected to fatigue loading and the difference between the fatigue life reinforced and unreinforced specimens is observed. Based on the preliminary study, it is expected, that the reinforcement will prolong the life expectancy by half.

  6. Analyses of quenching process during turn-off of plasma electrolytic carburizing on carbon steel

    Science.gov (United States)

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

    2014-10-01

    Plasma electrolytic carburizing (PEC) under different turn-off modes was employed to fabricate a hardening layer on carbon steel in glycerol solution without stirring at 380 V for 3 min. The quenching process in fast turn-off mode or slow turn-off mode of power supply was discussed. The temperature in the interior of steel and electron temperature in plasma discharge envelope during the quenching process were evaluated. It was found that the cooling rates of PEC samples in both turn-off modes were below 20 °C/s, because the vapor film boiling around the steel sample reduced the cooling rate greatly in terms of Leidenfrost effect. Thus the quench hardening hardly took place, though the slow turn-off mode slightly decreased the surface roughness of PEC steel. At the end of PEC treatment, the fast turn-off mode used widely at present cannot enhance the surface hardness by quench hardening, and the slow turn-off mode was recommended in order to protect the electronic devices against a large current surge.

  7. Magnetic-field-induced microstructural features in a high carbon steel during diffusional phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoxue, E-mail: zhangxiaoxue1213@gmail.com [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Zhang, Yudong, E-mail: yudong.zhang@univ-metz.fr [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Gong, Minglong, E-mail: gml@mail.neuq.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Esling, Claude, E-mail: claude.esling@univ-metz.fr [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Zhao, Xiang, E-mail: zhaox@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Zuo, Liang, E-mail: lzuo@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China)

    2012-12-15

    In this work, a high purity, high carbon steel was heat treated without and with a 12-T magnetic field. The microstructural features induced by magnetic field during its diffusion-controlled austenite decomposition were investigated by means of optical microscopy and SEM/EBSD. It is found that the magnetic field increases the amount of the abnormal structure, which is composed of proeutectoid cementite along the prior austenite boundaries and ferrite around it, because magnetic field increases the austenite grain size and promotes the transformation of carbon-depleted austenite to ferrite. No specific orientation relationship between abnormal ferrite and cementite has been found in the non-field- or the field-treated specimens. Magnetic field evidently promotes the spheroidization of pearlite, due to its effect of enhancing carbon diffusion through raising the transformation temperature and its effect of increasing the relative ferrite/cementite interface energy. As magnetic field favors the nucleation of the high magnetization phase-pearlitic ferrite, the occurrence of the P-P2 OR that corresponds to the situation that ferrite nucleates prior to cementite during pearlitic transformation is enhanced by the magnetic field. - Highlights: Black-Right-Pointing-Pointer The field-induced microstructural features in a high carbon steel during diffusional phase transformation has been investigated. Black-Right-Pointing-Pointer Magnetic field increases the amount of the abnormal structure and promotes the spheroidization of pearlite. Black-Right-Pointing-Pointer Magnetic field enhances the occurrence of the P-P2 OR.

  8. Pyrolytic carbon-coated stainless steel felt as a high-performance anode for bioelectrochemical systems.

    Science.gov (United States)

    Guo, Kun; Hidalgo, Diana; Tommasi, Tonia; Rabaey, Korneel

    2016-07-01

    Scale up of bioelectrochemical systems (BESs) requires highly conductive, biocompatible and stable electrodes. Here we present pyrolytic carbon-coated stainless steel felt (C-SS felt) as a high-performance and scalable anode. The electrode is created by generating a carbon layer on stainless steel felt (SS felt) via a multi-step deposition process involving α-d-glucose impregnation, caramelization, and pyrolysis. Physicochemical characterizations of the surface elucidate that a thin (20±5μm) and homogenous layer of polycrystalline graphitic carbon was obtained on SS felt surface after modification. The carbon coating significantly increases the biocompatibility, enabling robust electroactive biofilm formation. The C-SS felt electrodes reach current densities (jmax) of 3.65±0.14mA/cm(2) within 7days of operation, which is 11 times higher than plain SS felt electrodes (0.30±0.04mA/cm(2)). The excellent biocompatibility, high specific surface area, high conductivity, good mechanical strength, and low cost make C-SS felt a promising electrode for BESs.

  9. 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.

  10. Crack initiation and crack growth behavior of carbon and low-alloy steels

    Energy Technology Data Exchange (ETDEWEB)

    Gavenda, D.J.; Luebbers, P.R.; Chopra, O.K. [Argonne National Lab., IL (United States). Energy Technology Div.

    1997-01-01

    Section III of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. These curves were based on tests of smooth polished specimens at room temperature in air. The effects of reactor coolant environments are not explicitly addressed by the Code design curves, but recent test data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be a factor of {approx}70 shorter than in air. Results of fatigue tests that examine the influence of reactor environment on crack imitation and crack growth of carbon and low-alloy steels are presented. Crack lengths as a function of fatigue cycles were determined in air by a surface replication technique, and in water by block loading that leaves marks on the fracture surface. Decreases in fatigue life of low-alloy steels in high-dissolved-oxygen (DO) water are primarily caused by the effects of environment during early stages of fatigue damage, i.e., growth of short cracks <100 {micro}m in depth. For crack sizes of >100 {micro}m, crack growth rates in high-DO water are higher than in air by one order of magnitude. The effects of LWR environments on growth of short cracks are discussed.

  11. Fabrication and compressive performance of plain carbon steel honeycomb sandwich panels

    Institute of Scientific and Technical Information of China (English)

    Yu'an Jing; Shiju Guo; Jingtao Han; Yufei Zhang; Weijuan Li

    2008-01-01

    Plain carbon steel Q215 honeycomb sandwich panels were manufactured by brazing in a vacuum furnace. Their characteristic parameters, including equivalent density, equivalent elastic modulus, and equivalent compressive strength along out-of-plane (z-direction) and in-plane (x- and y-directions), were derived theoretically and then determined experimentally by an 810 material test system. On the basis of the experimental data, the compressive stress-strain curves were given. The results indicate that the measurements of equivalent Young's modulus and initial compressive strength are in good agreement with calculations, and that the maximum compressive strain near to solid can be up to 0.5-0.6 along out-of-plane, 0.6-0.7 along in-plane. The strength-to-density ratio of plain carbon steel honeycomb panels is near to those of Al alloy hexagonal-honeycomb and 304L stainless steel square-honeycomb, but the compressive peak strength is greater than that of Al alloy hexagonal-honeycomb.

  12. Effect of Niobium on Isothermal Transformation of Austenite to Ferrite in HSLA Low-Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    CAO Jian-chun; LIU Qing-you; YONG Qi-long; SUN Xin-jun

    2007-01-01

    Using thermomechanical simulation experiment, the kinetics of the isothermal transformation of austenite to ferrite in two HSLA low-carbon steels containing different amounts of niobium was investigated under the conditions of both deformation and undeformation. The results of optical microstructure observation and quantitative metallography analysis showed that the kinetics of the isothermal transformation of austenite to ferrite in lower niobium steel with and without deformation suggests a stage mechanism, wherein there exists a linear relationship between the logarithms of holding time and ferrite volume fraction according to Avrami equation, whereas the isothermal transformation of austenite to ferrite in high niobium steel proceeds via a two stage mechanism according to micrographs, wherein, the nucleation rate of ferrite in the initial stage of transformation is low, and in the second stage,the rate of transformation is high and the transformation of residual austenite to ferrite is rapidly complete. Using carbon extraction replica TEM, niobium carbide precipitation for different holding time was investigated and the results suggested that NbC precipitation and the presence of solute niobium would influence the transformation of austenite to ferrite. The mechanism of the effect of niobium on the isothermal transformation was discussed.

  13. Thermodynamic Research on Precipitates in Low Carbon Nb-Microalloyed Steels Produced by Compact Strip Production

    Institute of Scientific and Technical Information of China (English)

    Song XIANG; Guoquan LIU; Yang LI; Changrong LI; Andong WANG

    2007-01-01

    Microalloying element Nb in low carbon steels produced by compact strip production (CSP) process plays an important role in inhibiting recrystallization, decreasing the transformation temperature and grain refinement.With decreasing the rolling temperature, dislocations can be pinned by carbonitrides and the strength is increased. Based on the two sublattice model, with metal atom sublattice and interstitial atom sublattice,a thermodynamic model for carbonitride was established to calculate the equilibrium between matrix and carbonitride. In the steel produced by CSP, the calculation results showed that the starting temperature of precipitation of Ti and Nb are 1340℃ and 1040℃, respectively. In the range of 890-950℃, Nb rapidly precipitated. And the maximum of the atomic fraction of Nb in carbonitride was about 0.68. The morphologies and energy spectrum of the precipitates showed that (NbTi) (CN) precipitated near the dislocations. The experiment results show that Nb rapidly precipitated when the temperature was lower than 970℃, and the atomic fraction of Nb in carbonitride was about 60%-80%. The calculation results are in agreement with the experiment data. Therefore the thermodynamic model can be a useful assistant tool in the research on the precipitates in the low carbon steels produced by CSP.

  14. Inlfuence of carbon content on microstructure and mechanical properties of Mn13Cr2 and Mn18Cr2 cast steels

    Institute of Scientific and Technical Information of China (English)

    Lu Dingshan; Liu Zhongyi; Li Wei

    2014-01-01

    In this paper, a comparison study was carried out to investigate the inlfuence of carbon content on the microstructure, hardness, and impact toughness of water-quenched Mn13Cr2 and Mn18Cr2 cast steels. The study results indicate that both steels' water-quenched microstructures are composed of austenite and a smal amount of carbide. The study also found that, when the carbon contents are the same, there is less carbide in Mn18Cr2 steel than in Mn13Cr2 steel. Therefore, the hardness of Mn18Cr2 steel is lower than that of Mn13Cr2 steel but the impact toughness of Mn18Cr2 steel is higher than that of Mn13Cr2 steel. With increasing the carbon content, the hardness increases and the impact toughness decreases in these two kinds of steels, and the impact toughness of Mn18Cr2 steel substantialy exceeds that of Mn13Cr2 steel. Therefore, the water-quenched Mn18Cr2 steel with high carbon content could be applied to relatively high impact abrasive working conditions, while the as-cast Mn18Cr2 steel could be only used under working conditions of relatively low impact abrasive load due to lower impact toughness.

  15. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Science.gov (United States)

    Yuan, Hengguang; Hu, Shanglian; Huang, Peng; Song, Hua; Wang, Kan; Ruan, Jing; He, Rong; Cui, Daxiang

    2011-12-01

    Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  16. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Directory of Open Access Journals (Sweden)

    Huang Peng

    2011-01-01

    Full Text Available Abstract Herein we are the first to report that single-walled carbon nanotubes (SWCNTs exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  17. Anticorrosion Performance of Carbon Steel in 55% LiBr Solution Containing PMA/SbBr3 Inhibitor

    Institute of Scientific and Technical Information of China (English)

    HU Xian-qi; LIANG Cheng-hao; HUANG Nai-bao

    2006-01-01

    The anticorrosion performance of carbon steel in 55% LiBr solution containing PMA/SbBr3 inhibitor was studied by weight-loss tests, electrochemical measurements and surface analysis. In 55%LiBr+PMA/SbBr3 solution, corrosion rates of carbon steel at 145 ℃, 175 ℃, 190 ℃ and 240 ℃ are 18.32 μm·a-1, 27.68 μm·a-1, 53.58 μm·a-1 and 73.78 μm·a-1, respectively. PMA/SbBr3 inhibitor may inhibit the corrosion of carbon steel in 55% LiBr solution effectively. Especially, it shows an excellent corrosion inhibition performance at high temperature. Both anodic and cathodic reactions of carbon steel may be inhibited by PMA/SbBr3 inhibitor, so it may be classified as mixed inhibitor. In 55%LiBr+PMA/SbBr3 solution, the apparent activation energy of the corrosion reaction of carbon steel is 29.61 kJ·mol-1. The corrosion inhibition mechanism of PMA/SbBr3 is suggested as follows: PMA has the effect of inhibiting hydrogen evolution and a strong oxidizing property; Sb3+ also exhibits oxidizing properties, and can exist stably with PMA in LiBr solutions; the passive film comprising Fe2O3 and antimony formed on carbon steel surface may prevent Br- from diffusing into the metal surface due to the synergistic effect of PMA and Sb3+; As a result, the anticorrosion performance of carbon steel may be improved by PMA/SbBr3 inhibitor in 55% LiBr solution.

  18. Effects of Rolling and Cooling Conditions on Microstructure and Mechanical Properties of Low Carbon Cold Heading Steel

    Institute of Scientific and Technical Information of China (English)

    LI Zhuang; WU Di; LV Wei

    2012-01-01

    Effects of rolling and cooling conditions on microstructure and mechanical properties of low carbon cold heading steel were investigated on a laboratory hot rolling mill. The results have shown that the mechanical proper ties of low carbon steels exceed the standard requirements of ML30, ML35, ML40, and ML45 steel, respectively due to thermomechanical controlled processing (TMCP). This is attributed to a significant amount of pearlite and the ferrite-grain refinement. Under the condition of relatively low temperature rolling, the mechanical properties exceed standard requirements of ML45 and ML30 steel after water cooling and air cooling, respectively. Fast cooling which leads to more pearlite and finer ferrite grains is more critical than finish rolling temperatures for low carbon cold heading steel. The specimen at high finish rolling temperature exhibits very good mechanical properties due to fast cooling. This result has great significance not only for energy saving and emission reduction, but also for low-carbon economy, because the goals of the replacement of medium-carbon by low-carbon are achieved with TMCP.

  19. Influence of the carbon content on the phase composition and mechanical properties of P92-type steel

    Science.gov (United States)

    Dudko, V. A.; Fedoseeva, A. E.; Belyakov, A. N.; Kaibyshev, R. O.

    2015-11-01

    The deformation behavior and the microstructure evolution under the creep of 10Kh9V2MFBR steel (Russian analog of the P92 steel) (in wt %, Fe-8.9% Cr-0.05% Si-0.2% Mn-1.9% W-0.5% Mo-0.25% V-0.07Nb-0.08% N-0.01% B) with the standard (0.1%) and lowered (0.018%) carbon contents have been investigated. After the heat treatment, which included normalizing at 1050°C and tempering at 720-750°C, carbides M 23 C 6 and carbonitrides M(C,N) are formed in the 10Kh9V2MFBR steel, while in the 02Kh9V2MFBR steel (modified P92 steel), carbides M 23 C 6, nitrides M 2N, and carbonitrides M(C,N) as well as δ-ferrite (23%) were found. The measurements of hardness and tensile tests at room and elevated temper-atures did not reveal substantial distinctions in the short-term mechanical properties of both steels. The hardness of steels after tempering was 220 HB. At the same time, the creep characteristics of the steels were found to be different. A decrease in the carbon content leads to an increase in the long-term creep strength and creep limit at 650°C for short-term tests with time-to-fracture shorter than 103 h. The time to fracture of steels with various carbon contents is almost the same in long-term creep tests. Factor responsible for such effect of carbon on the creep strength are discussed.

  20. Pyrolysis-catalysis of waste plastic using a nickel-stainless-steel mesh catalyst for high-value carbon products.

    Science.gov (United States)

    Zhang, Yeshui; Nahil, Mohamad A; Wu, Chunfei; Williams, Paul T

    2017-02-03

    A stainless-steel mesh loaded with nickel catalyst was produced and used for the pyrolysis-catalysis of waste high-density polyethylene with the aim of producing high-value carbon products, including carbon nanotubes (CNTs). The catalysis temperature and plastic-to-catalyst ratio were investigated to determine the influence on the formation of different types of carbon deposited on the nickel-stainless-steel mesh catalyst. Increasing temperature from 700 to 900°C resulted in an increase in the carbon deposited on the nickel-loaded stainless-steel mesh catalyst from 32.5 to 38.0 wt%. The increase in sample-to-catalyst ratio reduced the amount of carbon deposited on the mesh catalyst in terms of g carbon g(-1) plastic. The carbons were found to be largely composed of filamentous carbons, with negligible disordered (amorphous) carbons. Transmission electron microscopy analysis of the filamentous carbons revealed them to be composed of a large proportion (estimated at ∼40%) multi-walled carbon nanotubes (MWCNTs). The optimum process conditions for CNT production, in terms of yield and graphitic nature, determined by Raman spectroscopy, was catalysis temperature of 800°C and plastic-to-catalyst ratio of 1:2, where a mass of 334 mg of filamentous/MWCNTs g(-1) plastic was produced.

  1. 78 FR 76653 - Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and...

    Science.gov (United States)

    2013-12-18

    ... COMMISSION [Investigation Nos. 701-TA-417 and 731-TA-953, 957-959, 961, and 962 (Second Review)] Carbon and Certain Alloy Steel Wire Rod From Brazil, Indonesia, Mexico, Moldova, Trinidad and Tobago, and Ukraine Scheduling of full five-year reviews concerning the countervailing duty order on carbon and certain...

  2. Extended X-Ray Absorption Fine Structure Investigation of Carbon Stabilized Expanded Austenite and Carbides in Stainless Steel AISI 316

    DEFF Research Database (Denmark)

    Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny;

    2011-01-01

    Low temperature carburized AISI 316 stainless steel - carbon expanded austenite - was investigated with EXAFS and synchrotron diffraction together with synthesized carbides of the type M3C2, M7C3 and M23C6. It was found that the chemical environment of carbon expanded austenite is not associated ...

  3. Influence of Carbon Content and Rolling Temperature on Rolling Texture in 3 Pct Si Steel

    Science.gov (United States)

    Shingaki, Y.; Takashima, M.; Hayakawa, Y.

    2017-01-01

    Effects of carbon and rolling temperature up to 453 K (180 °C) on rolling texture of 3 pct Si steel at a reduction of 66 pct were investigated using a single crystal with an initial orientation of {110}. With residual-level carbon, uniform slip deformation was observed in the specimen cold rolled at room temperature and most of initial orientation {110} rotated to {111} during the rolling. With carbon addition, the formation of the deformation twins and the shear bands were promoted in the specimen cold rolled at room temperature. Regions with {110} were observed inside the shear bands. Warm-rolled specimen with residual-level carbon had microbands containing tiny {110} regions. Warm-rolled specimen with carbon addition had both the shear bands and the microbands but no deformation twin. Additionally, there were unique band structures with rotated crystal orientation around the rolling direction from initial orientation {110}. These experimental results suggest that the carbon addition inhibits dislocation migration by the increase of the critical resolved shear stress (CRSS) and that the high deformation temperature activates multiple slip systems by the reduction of CRSS and further that the carbon addition and high deformation temperature superimposed bring about the activation of symmetrical {110} slip systems additionally.

  4. Influence of Carbon Content and Rolling Temperature on Rolling Texture in 3 Pct Si Steel

    Science.gov (United States)

    Shingaki, Y.; Takashima, M.; Hayakawa, Y.

    2016-10-01

    Effects of carbon and rolling temperature up to 453 K (180 °C) on rolling texture of 3 pct Si steel at a reduction of 66 pct were investigated using a single crystal with an initial orientation of {110}. With residual-level carbon, uniform slip deformation was observed in the specimen cold rolled at room temperature and most of initial orientation {110} rotated to {111} during the rolling. With carbon addition, the formation of the deformation twins and the shear bands were promoted in the specimen cold rolled at room temperature. Regions with {110} were observed inside the shear bands. Warm-rolled specimen with residual-level carbon had microbands containing tiny {110} regions. Warm-rolled specimen with carbon addition had both the shear bands and the microbands but no deformation twin. Additionally, there were unique band structures with rotated crystal orientation around the rolling direction from initial orientation {110}. These experimental results suggest that the carbon addition inhibits dislocation migration by the increase of the critical resolved shear stress (CRSS) and that the high deformation temperature activates multiple slip systems by the reduction of CRSS and further that the carbon addition and high deformation temperature superimposed bring about the activation of symmetrical {110} slip systems additionally.

  5. Study on Carburizing Kinetics of Low-carbon Steel at High-temperature and Short-term

    Institute of Scientific and Technical Information of China (English)

    Lu Sheng; Xiao Nianxin; Zhang Hailong

    2007-01-01

    In this paper, the carburizing kinetics of low-carbon steel at high-temperature and short-term in liquid cast-iron were studied by metallographic microscope, chemical analysis and so on, and the microstructure of carburized layer was also analyzed. The results show that the carburizing rate of low-carbon steel at high-temperature and short-term is so fast, and the microstructure of carburized layer possess higher carbon content, and cementite, pearlite and ferrite exist in carburized layer structure simultaneously. Besides, the kinetic equations of permeating layer forming have been presented, and the carburizing mechanism was preliminary discussed also.

  6. Electrochemical Impedance and Modelling Studies of the Corrosion of Three Commercial Stainless Steels in Molten Carbonate

    Directory of Open Access Journals (Sweden)

    C. S. Ni

    2014-01-01

    Full Text Available The corrosion induced by molten carbonates on the metallic structure materials is a problem constraining the life span of molten carbonate fuel cell (MCFC at elevated temperatures. The reaction between the outgrowing oxide scale and lithium carbonate in the electrolyte is generally a slow process and very important to the passivation behaviour of the underlying steel. The corrosion behaviour of three commercial alloys (P92, SS304, and SS310 with different Cr contents in molten (0.62Li, 0.38K2CO3 at 650°C was monitored by electrochemical impedance spectroscopy (EIS for 120 hours to investigate the lithiation process. With SEM images and extensive XRD analysis of the oxides, equivalent circuits were proposed to interpret the impedance data and explain the corrosion behaviour of the three alloys at different stage with respect to lithiation process.

  7. STUDY ON FATIGUE SHORT CRACK GROWTH LAW AND FATIGUE LIFE FOR MEDIUM CARBON STEELS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The fatigue crack initiation from notch root and the short-crack growth laws of two medium carbon alloying structural steels-35CrMo and 42CrMo are investigated under the different stress ratios R=0.1, 0.3) and three-point bending condition. The relationships between the maximum stress range at the notch root Δσmax and the number of cycles before fatigue crack initiation Ni are determined. The threshold stresses of fatigue crack initiation (Δσmax)th are got, and the smallcrack growth laws are obtained for these steels. An effective and convenient method is proposed for predicting the fatigue life of the notch specimens.

  8. When can Electrochemical Techniques give Reliable Corrosion Rates on Carbon Steel in Sulfide Media?

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, Tor; Nielsen, Lars Vendelbo

    2005-01-01

    Effects of film formation on carbon steel in hydrogen sulfide media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from hydrogen sulfide solutions, biological sulfide media and natural sulfide containing geothermal water have been collected and the process...... corrosion rates, but this effect may not be detected if rates are already overestimated. It is concluded that electrochemical techniques can be used for corrosion rate monitoring in som hydrogen sulfide media, but care must be taken when choosing the scan rates, and it is important to realize when direct...... in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Oxygen entering the system accelerates...

  9. Reliability of Electrochemical Techniques for Determining Corrosion Rates on Carbon Steel in Sulfide Media

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, T.; Nielsen, Lars Vendelbo

    2007-01-01

    Effects of film formation on carbon steel in hydrogen sulfide (H2S) media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from H2S solutions, biological sulfide media, and natural sulfide containing geothermal water have been collected, and the process...... if the biofilm in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemicel impedance spectroscopy (EIS). Oxygen entering the system...... accelerates corrosion rates, but this effect may not be detected if rates are already overestimated. It is concluded that electrochemical techniques can be used for corrosion reate monitoring in some H2S media, but care must be taken in the choice of scan ratre; it is important to realize when direct...

  10. 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.

  11. A NOVEL PARAMETER FOR EVALUATING THE FATIGUE CRACK GROWTH RATE IN CARBON STEELS

    Institute of Scientific and Technical Information of China (English)

    X.S.Wang; S.Q.Zhu; N.Kawagoishi; H.Nisitani

    2001-01-01

    A novel parameter is suggested for evaluating the fatigue crack growth rate in carbonsteels.Fatigue crack propagation tests of an annealed 0.42% carbon steel were carriedout under different conditions to investigate the relationship between this dominatingparameter and the crack opening displacement (COD).A new equation of fatiguecrack growth rate is formulated in terms of the suggested parameter.The physicalmeanings of the material parameters in this equation are explored experimentally.Considering the relation of crack growth and deformation properties,a simple andapplicable method is proposed to evaluate the fatigue crack growth rate.It is alsoobserved that the material parameters in the fatigue crack growth rate equation ofcarbon steels are related linearly to the material strength.The results are in a goodagreement with experimental results.

  12. Effect of silicon and prior deformation of austenite on isothermal transformation in low carbon steels

    Institute of Scientific and Technical Information of China (English)

    Minghui CAI; Hun DING; Jiansu ZHANG; Long LI

    2009-01-01

    Isothermal transformation (TTT) behavior of the low carbon steels with two Si con-tents (0.50 wt pct and 1.35 wt pct) was investigated with and without the prior deformation. The results show that Si and the prior deformation of the austenite have significant effects on the transformation of the ferrite and bainite. The addition of Si refines the ferrite grains, accelerates the polygonal ferrite transformation and the formation of M/A constituents, leading to the improvement of the strength. The ferrite grains formed under the prior deformation of the austenite become more ho-mogeneous and refined. However, the influence of deformation on the tensile strength of both steels is dependent on the isothermal temperatures. Thermodynamic calcu-lation indicates that Si and prior deformation reduce the incubation time of both ferrite and bainite transformation, but the effect is weakened by the decrease of the isothermal temperatures.

  13. Effect of Al on Microstructures and Mechanical Properties of the Ultrahigh Carbon Steels

    Institute of Scientific and Technical Information of China (English)

    Huifen PENG; Baoqi WANG; Jianjun ZHANG; Xiaoyan SONG; Xiaoli MA; Nanju GU

    2004-01-01

    In this research, we tried to find a simple processing method to break up the network carbides in ultrahigh carbon steels (UHCS). Our results revealed that Al addition was favorable to the decrease in the proeutectoid carbides, the pearlite-colony size and the pearlitic interlamellar spacing of the forged microstructures, and that a fully-pearlitic structure was obtained in the UHCS containing 1.6 wt pct Al. The quenching-and-tempering process resulted in fine microstructure in those steels. On the other hand, the strength of the UHCSs increased with the increase of the Al content, and the highest strength was obtained at the UHCS with 1.6 wt pct Al. The UHCSs with Al contents higher than 1.3 wt pct showed a high tensile strength of more than σb=1000 MPa and good ductility of higher than δ5=10% at ambient temperature.

  14. Corrosion Behavior of Low-Alloy Pipeline Steel Exposed to H2S/CO2-Saturated Saline Solution

    Science.gov (United States)

    Liu, Zhenguang; Gao, Xiuhua; Du, Linxiu; Li, Jianping; Li, Ping; Bai, Xiaolei; Misra, R. D. K.

    2017-02-01

    Immersion experiments were carried out to study H2S/CO2 corrosion behavior of low-alloy pipeline steel in terms of microstructure, corrosion kinetics, corrosion phases, microscopic surface morphology, cross-sectional morphology and elemental distribution. The experimental results indicated that the microstructure of designed steel was tempered martensite. The corrosion rate followed exponential behavior. H2S corrosion dominated the corrosion process, and the corrosion products were mackinawite, greigite and troilite. The corrosion products changed from mackinawite/greigite to mackinawite/troilite, and mackinawite dominated the corrosion phases. The corrosion products became more compact with immersion time, which led to decrease in corrosion rate. The chromium and molybdenum content in the corrosion product was higher than that in the steel substrate.

  15. Scale formation and descaling in hot rolling of low carbon steel

    Science.gov (United States)

    Basabe Mancheno, Vladimir Vinicio

    In this research, the effects of gas composition, elapsed time of reaction and temperature on scale formation and descaling of low carbon steel were investigated and results were discussed from the viewpoint of the phase composition of the scales, oxidation rates, oxidation mechanisms, adhesion, fracture mechanics, porosity and residual scale. The phase composition and morphology of scales grown under conditions similar to those of reheating furnaces were analyzed. Low carbon steel was oxidized over the temperature range 1000-1250°C in gas mixtures of O 2-CO2-H2O-N2, O2-H 2O-N2 and O2-CO2-N2. The mole fraction of each phase, wustite (FeO), magnetite (Fe3O 4) and hematite (Fe2O3) was determined by the direct comparison method Two types of scales were observed. The first type was a crystalline scale with an irregular outer surface composed mostly of wustite, and a negligible amount of magnetite. The second type was the classical three-layer scale composed of wustite, magnetite and hematite. In general, the experiments showed that the furnace atmosphere, oxidation time and temperature influence the phase composition of the scales. Low carbon steel was oxidized in air over the temperature range 600-1200°C for 120 s to approximate the formation of secondary and tertiary scale in hot rolling. The mole fraction of wustite, magnetite and hematite was determined by the direct comparison method The phase composition of the scales changed with temperature and time. During the initial 30 s of oxidation, wustite was the predominant phase in the temperature range 800-1200°C, and as oxidation proceeded, the percentages of magnetite and hematite increased. In addition, the texture of the scales was investigated by orientation imaging microscopy (OIM); it was found that temperature influences the texture of the scales. The experiments indicated that 850°C is the ideal temperature for the finishing mill in order to reduce surface defects and work roll wear. The adhesion of

  16. Modelling of induction heating of carbon steel tubes: Mathematical analysis, numerical simulation and validation

    Energy Technology Data Exchange (ETDEWEB)

    Di Luozzo, N. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Fontana, M., E-mail: mfontan2006@gmail.com [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Arcondo, B. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, C1063ACV Buenos Aires (Argentina)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Numerical simulations of the heating by induction in steel tubes were performed. Black-Right-Pointing-Pointer Finite element method was employed in this electromagnetic-heat transfer coupled problem. Black-Right-Pointing-Pointer The outside temperature evolution of the steel tubes was determined experimentally and numerically. Black-Right-Pointing-Pointer Temperatures in the inner and outer tube surface and the heat affected zone were determined. - Abstract: The transient liquid phase bonding process is been performed to join carbon steel tubes. Fe{sub 96.2}B{sub 3.8} wt% amorphous ribbons of thickness a Almost-Equal-To 20 {mu}m have been employed as filler material. The tubes are aligned with their butted surfaces in contact with the amorphous layer. The joint is heated into a high frequency induction coil under Argon atmosphere. The temperature is raised at the highest possible rate to the process temperature (at about Almost-Equal-To 1250 Degree-Sign C) and then held for a predetermined time. In this paper, the numerical simulations of the heating stage of the bonding process have been made using the finite element method. This method had shown of being able to deal with these kind of coupled problems: electromagnetic field generated by alternating currents, eddy currents generated on the steel tube, heating of the steel tube due to joule effect and heat transfer by conduction, convection and radiation. The experimental heating stage, for its further simulation, was done with carbon steel tubes. In particular, we are interested in the temperature evolution of the tube upon heating: time to reach the process temperature at the joint, temperature differences between the inner and outer surface of the tube and the extension of the heat affected zone, taking into account the ferromagnetic-paramagnetic transition. The numerical simulations are validated by comparison with infrared radiation thermometer measurements of the

  17. An Experimental Investigation of Galvanic Anode Specifications for Suitable Cathodic Corrosion Protection of Low Carbon Steel in Kaduna Metropolitan Soil

    Directory of Open Access Journals (Sweden)

    T.N. Guma

    2016-06-01

    Full Text Available The paper stresses corrosion risks from huge underground engineering steel structures within the metropolitan area of Kaduna-a top city in Nigeria. Cathodic protection (CP is examined as an effective, economical and durable method of preventing corrosion of such structures if suitably designed-installed. Variables that can cause wide differences and difficulties in CP designs such as material make, surface area and nature of structure, corrosivity level of environment, etc, are recognized. Some supplementary information that accounts for complexity of such variables which can be used to optimize CP design of the structures was sought experimentally. Relative performances by zinc, pure magnesium and magnesium alloy as common and cheap galvanic anodes were investigated in a laboratory CP of polished bare low carbon steel specimens in soil of surveyed resistivity spectrum 31.9-152.9 ohm-m from the area. Specimens were exposed with and without CP by the anodes at ambient temperature up to 40 days in various samples of the soil. Levels of specimen protections were determined by analysis of obtained information on their corrosion rates and polarized potentials relative to the un-protected ones at 8-day intervals. The analysis indicated that; corrosion of the structures can be optimally reduced to negligible rates by polarizing them to -0.85V versus Cu/CuSO4 electrode with the anodes, pure magnesium is comparatively the best of the anodes for CP of the structures in terms of economy and effectiveness followed by magnesium alloy, and a unit surface area of the anodes can protect up to nearly 1200 units of the structure with the -0.85V protective potential depending on the anode type.

  18. Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale

    Science.gov (United States)

    Hossain, R.; Pahlevani, F.; Quadir, M. Z.; Sahajwalla, V.

    2016-10-01

    Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels’ performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano scale of the compressive stability of retained austenite in high carbon martensitic steel. Using a combination of standard compression testing, X-ray diffraction, optical microstructure, electron backscattering diffraction imaging, electron probe micro-analysis, nano-indentation and micro-indentation measurements, we determined the mechanical stability of retained austenite and martensite in high carbon steel under compressive stress and identified the phase transformation mechanism, from the macro to the nano level. We found at the early stage of plastic deformation hexagonal close-packed (HCP) martensite formation dominates, while higher compression loads trigger body-centred tetragonal (BCT) martensite formation. The combination of this phase transformation and strain hardening led to an increase in the hardness of high carbon steel of around 30%. This comprehensive characterisation of stress induced phase transformation could enable the precise control of the microstructures of high carbon martensitic steels, and hence their properties.

  19. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Weimin Song

    2016-08-01

    Full Text Available Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF and carbon fiber (CF was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC, carbon fiber reinforced concrete (CFRC and hybrid fiber reinforced concrete (HFRC were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored.

  20. Microhardness tests of stainless steel 52100 implanted with nitrogen and carbon dioxide

    CERN Document Server

    Mardanian, M; Taheri, Z

    2003-01-01

    In this research work, samples of stainless steel 52100 disks were implanted with nitrogen and carbon dioxide ions at the energy of 90 keV. Microhardness measurement were performed to determine the hardness of the surface. The N-2 sup + implanted steels at the doses of 1x10 sup 1 8 ions cm sup sub 2 gave the highest hardness of 49.70%, while for the CO sub 2 sup + ions implantation, the hardness of 17% and 5% were obtained at the doses of 3x10 sup 1 8 and 1x10 sup 1 9 ions cm sup - 2, respectively. To support the interpretation of our microhardness results the implanted surface were analyzed by the use of XRD method. Our results indicated that the hardness of the N sub 2 sup + implanted samples are due to formation of beta-Cr N phase in the surface layer, while in the CO sub 2 + implanted samples no observation of carbon as graphite or carbide was made. In addition, the absence of any hump in the XRD spectrum indicating that carbon is not in the amorphous phase either.

  1. The relationship between microbial metabolic activity and biocorrosion of carbon steel.

    Science.gov (United States)

    Dzierzewicz, Z; Cwalina, B; Chodurek, E; Wilczok, T

    1997-12-01

    The effect of metabolic activity (expressed by generation time, rate of H2S production and the activity of hydrogenase and adenosine phosphosulphate (APS)-reductase enzymes) of the 8 wild strains of Desulfovibrio desulfuricans and of their resistance to metal ions (Hg2+, Cu2+, Mn2+, Zn2+, Ni2+, Cr3+) on the rate of corrosion of carbon steel was studied. The medium containing lactate as the carbon source and sulphate as the electron acceptor was used for bacterial metabolic activity examination and in corrosive assays. Bacterial growth inhibition by metal ions was investigated in the sulphate-free medium. The rate of H2S production was approximately directly proportional to the specific activities of the investigated enzymes. These activities were inversely proportional to the generation time. The rate of microbiologically induced corrosion (MIC) of carbon steel was directly proportional to bacterial resistance to metal ions (correlation coefficient r = 0.95). The correlation between the MIC rate and the activity of enzymes tested, although weaker, was also observed (r = 0.41 for APS-reductase; r = 0.69 for hydrogenase; critical value rc = 0.30, p = 0.05, n = 40).

  2. ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES

    Energy Technology Data Exchange (ETDEWEB)

    BOOMER, K.D.

    2007-01-31

    The effect of the important chemical constituents in the Hanford nuclear waste simulant on the anodic behavior of carbon steel was studied. Specifically, the effect of pH, nitrite concentration, nitrite/nitrate concentration ratios, total organic carbon and the chloride concentration on the open circuit potential, pitting potential and repassivation potential was evaluated. It was found that pH adjusting, although capable of returning the tank chemistry back to specification, did not significantly reduce the corrosivity of the stimulant compared to the present condition. Nitrite was found to be a potent inhibitor for carbon steel. A critical concentration of approximately 1.2M appeared to be beneficial to increase the difference of repassivation potential and open circuit potential considerably and thus prevent pitting corrosion from occurring. No further benefit was gained when increasing nitrite concentration to a higher level. The organic compounds were found to be weak inhibitors in the absence of nitrite and the change of chloride from 0.05M to 0.2M did not alter the anodic behavior dramatically.

  3. Influence of carbon content on superplastic behavior in Ti- and B-added Cr-Mo steels

    Energy Technology Data Exchange (ETDEWEB)

    Aramaki, M.; Higashida, K.; Onodera, R. [Kyushu Univ., Fukuoka (Japan). Dept. of Materials Science and Engineering

    1999-05-01

    Superplasticity has been investigated in various ferrous alloys and steels. However, in these materials, especially in hypoeutectoid steels below the A{sub 1} temperature, the relationship between the content of carbon and elongation to failure is not obvious. In the present investigation, the influence of carbon content on superplastic behavior is studied using carbon steels based on Cr-Mo steel. In order to obtain the fine grain structure, a small amount of Ti and B were added and the content of carbon was controlled to be in the range from 0.24 to 0.83 pct. The largest value of elongation to failure was 644 pct, which was obtained for a specimen containing 0.58 pct carbon. The temperature and strain rate at which the maximum value was obtained were 710 C and 5 {times} 10{sup {minus}4} s{sup {minus}1}, respectively. Of all the specimens, this specimen had the minimum grain size. Moreover, the area fraction of carbide took the maximum value at the temperature where the largest elongation value was obtained. These results show that the addition of carbon has an effect on grain refinement by the formation of carbide, but excess amounts of carbon (>0.6 pct) bring about premature failure because of the resulting coarse microstructure and larger carbides.

  4. Urinary homovanillic acid and vanillylmandelic acid in workers exposed to carbon disulfide.

    Science.gov (United States)

    Yang, X F; Lee, B L; New, A L; Ong, H Y; Ma, L; Zhang, Q; Ong, C N

    1996-03-01

    Homovanillic acid (HVA) and vanillylmandelic acid (VMA), two end products of dopamine metabolism, were measured in 60 workers exposed to carbon disulfide (CS(2)) in a rayon factory and in 48 unexposed workers. The airborne CS(2) concentrations in eight major exposure zones of the plant were measured monthly over a period of 4 years, from 1990 to 1994. In addition, the exposure concentrations and exposure history of each worker were integrated to estimate the overall lifetime exposure. Industrial hygiene data showed that the geometric mean concentrations of CS(2) in the plant ranged from 2.68 to 20.19 ppm, and more than 15% of the studied population had been repeatedly exposed to CS(2) at concentrations exceeding the ACGIH recommended time-weighted average of 10 ppm. The results showed that there was a significantly lower level and a higher proportion of CS(2) workers with decreased HVA and VMA excretion. However, there were no statistical correlations between the two dopaminergic metabolites and the mean CS(2) concentration, and years of employment. In contrast, significant dose-effect relationships were observed between these two metabolites and the integrated cumulative exposure (ICE) variable. The correlation coefficients for ICE and HVA, and ICE and VMA were -0.35 (p < 0.01) and -0.20 (p <0.05), respectively. These data suggest that chronic exposure to CS(2) was associated with measurable reduction in catecholamine metabolite concentrations. This finding is compatible with the earlier observations in laboratory animals that CS(2) exposures interfere with neurochemical metabolism.

  5. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Li Ling; Xie Huasheng; Huang Danzhong; Li Hankun; Tan Rui; Zhou Jingyi

    2008-01-01

    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 bum-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.

  7. Characterization of the corrosion behavior of different stainless steel alloys exposed to flowing fresh seawater, using E.I.S technique

    Energy Technology Data Exchange (ETDEWEB)

    Al Muhanna, K. [Petroleum Research and Studies Center, Kuwait Institute for Scientific Research, KISR, P.O.Box 24885, Safat 13109 Kuwait (Kuwait)

    2004-07-01

    E.I.S technique was used to characterize the corrosion behavior of UNS NO. S 31600 stainless steel, UNS NO. S 30400 stainless steel and UNS NO. S 62800 sanicro 28 exposed to continuous fresh Seawater. The total exposure time of the test was about 180 days. Two types of additives (4 ppm of Cl{sub 2} and 5 ppm of NH{sub 3}) were also added to the seawater to investigate their effect on the surfaces of these alloys. During the tests, no marine - macro fouling was observed on the surfaces of the tested alloys, as the seawater was filtrated at the Doha Desalination Research Center, where the study was carried out, but only a slimy layer spread on the whole surface of the alloys. The corrosion behavior of each alloy was monitored by the open circuit potential measurement, and the E.I.S technique using the EG and G 352 software and hardware instrument, where the resistance of the solution (R{sub sol}), the resistance of the surface of the tested alloy (R{sub p}), and the double layer capacitance (Cdl) was calculated. Under this study's experimental conditions, results indicated that the stainless steel alloys were highly resistant to marine fouling and corrosion in seawater, and were not affected by the aggressive additives, such as NH{sub 3}, and Cl{sub 2} in the seawater. (author)

  8. Carbon steel corrosion in the low-pressure turbine exhaust environment

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Andrew G. [Xcel Energy, Golden, CO (United States)

    2010-11-15

    Corrosion of carbon steel on the steam side of condensers has long been observed by power plant operators, but the mechanism has not been well understood. Characteristics of the corrosion are areas of bare metal resulting from intergranular attack intermixed with black or red iron oxide, condensing high-purity steam with high local velocities, the lowest temperature in the steam cycle, and relative constancy over time in the macroscopic corrosion pattern. Effective mitigation would reduce iron transport into the steam cycle from the condenser, and might also reduce the likelihood of through-wall leaks in the cooling tubes of air-cooled condensers. (orig.)

  9. Mechanism of Austenite Evolution During Deformation of Ultra-High Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-lan; SUN Xin-jun; DONG Han

    2008-01-01

    The mechanism of transformation of austenite to cementite and pearlite during the deformation of ultra-high carbon steel was discussed. The results indicate that the pearlite and cementite can be induced by deformation be-tween Acm to Arcm. The transformation during deformation is still considered as a diffusion-controlled process. With the increase of time and reduction, the pearlite fraction increased. At the beginning of the transformation, the pearli- te was lamelliform. When the rate of reduction was increased to 70%, some of the induced lamellar pearlite was bro-ken up under deformation.

  10. STUDY OF DYNAMIC RECRYSTALLIZATION OF LOW CARBON STEEL IN THIN SLAB CONTINUOUS ROLLING PROCESS

    Institute of Scientific and Technical Information of China (English)

    X.K. Liang; X.J. Sun; Q.Y. Liu; H. Dong

    2006-01-01

    Combined with the technological characteristics of thin slab continuous rolling process (TSCR),dynamic recrystallization of an extremely coarse austenite of low carbon steel is studied by Thermecmaster-Z hot simulator. By the analysis of true stress-strain curves and the observation of microstructures at different deformation stages, the critical stress and critical strain are determined under different deformation conditions. The effect of Z parameter on dynamic recrystallization of coarse austenite is studied. The microstructure evolution in real production is also discussed.

  11. 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.

  12. New Spheroidizing Technique of Ultra-High Carbon Steel With Aluminum Addition

    Institute of Scientific and Technical Information of China (English)

    LI Hong-juan; WANG Bao-qi; SONG Xiao-yan; GUO Su-zhen; GU Nan-ju

    2006-01-01

    A new spheroidizing process of ultra-high carbon steel (UHCS) containing C 1.55%, Cr 1.45%, and Al 1.5% in mass percent has been proposed. The effect of processing parameters on the microstructure was analyzed. The UHCS produced by this new process has a microstructure with recrystallized ferrite matrix and fine and uniform carbide particles. After this spheroidizing, the UHCS exhibits good mechanical properties at ambient temperature, for example σb=1 100 MPa, σs=915 MPa, δ=8% and high ratio of σs/σb.

  13. Carbon emissions due to deforestation for the production of charcoal used in Brazil’s steel industry

    Science.gov (United States)

    Sonter, Laura J.; Barrett, Damian J.; Moran, Chris J.; Soares-Filho, Britaldo S.

    2015-04-01

    Steel produced using coal generates 7% of global anthropogenic CO2 emissions annually. Opportunities exist to substitute this coal with carbon-neutral charcoal sourced from plantation forests to mitigate project-scale emissions and obtain certified emission reduction credits under the Kyoto Protocol’s Clean Development Mechanism. This mitigation strategy has been implemented in Brazil and is one mechanism among many used globally to reduce anthropogenic CO2 emissions; however, its potential adverse impacts have been overlooked to date. Here, we report that total CO2 emitted from Brazilian steel production doubled (91 to 182 MtCO2) and specific emissions increased (3.3 to 5.2 MtCO2 per Mt steel) between 2000 and 2007, even though the proportion of coal used declined. Infrastructure upgrades and a national plantation shortage increased industry reliance on charcoal sourced from native forests, which emits up to nine times more CO2 per tonne of steel than coal. Preventing use of native forest charcoal could have avoided 79% of the CO2 emitted from steel production between 2000 and 2007; however, doing so by increasing plantation charcoal supply is limited by socio-economic costs and risks further indirect deforestation pressures and emissions. Effective climate change mitigation in Brazil’s steel industry must therefore minimize all direct and indirect carbon emissions generated from steel manufacture.

  14. Microstructural evolution and mechanical behaviour of surface hardened low carbon hot rolled steel

    Energy Technology Data Exchange (ETDEWEB)

    Tewary, N.K. [Department of Metallurgy and Materials Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Syed, B. [R and D Division, Tata Steel Limited, Jamshedpur 831007 (India); Ghosh, S.K., E-mail: skghosh@metal.becs.ac.in [Department of Metallurgy and Materials Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Kundu, S. [R and D Division, Tata Steel Limited, Jamshedpur 831007 (India); Shariff, S.M.; Padmanabham, G. [Centre for Laser Processing, ARCI-Hyderabad, Balapur PO, AP 500005 (India)

    2014-06-01

    Surface hardening of low carbon hot rolled C–Mn steel has been successfully performed by high power diode laser with an achievable case depth of about 300 μm. The laser treated samples have been characterised using optical microscope, scanning electron microscope, transmission electron microscope, and X-ray diffraction techniques. Higher hardness level is achieved in laser surface hardened zone (≈300 HV) than in the base alloy region (≈140 HV). The variation in hardness as a function of distance across the laser tracks is observed during multi-track laser hardening. Laser hardened steel sheets show enhanced mechanical strength (YS: 383–443 MPa, UTS: 476–506 MPa) with the lowering of percentage total elongation (23–28%) compared to the base alloy (YS: 351 MPa, UTS: 450 MPa and total elongation is 32%). Strain hardening exponent (‘n’) has been evaluated from true tensile stress–strain diagram and it shows a similar nature for both base alloy and laser treated steels. The microstructure in the base alloy region consists of a mixture of ferrite and pearlite, whereas predominantly lath martensite is present in the laser hardened surface layer. The improvement of mechanical strength is discussed in terms of the formation of this hardened layer on the surface.

  15. Theoretical and Experimental on Carbon Dioxide Sequestration Degree of Steel Slag

    Institute of Scientific and Technical Information of China (English)

    LI Jian-li; ZHANG Hui-ning; XU An-jun; CUI Jian; HE Dong-feng; TIAN Nai-yuan

    2012-01-01

    The limitation and experimental CO2 sequestration degree of steel slag is the focus. The theoretical and the practical COe sequestration degree was assessed under mild operating conditions. After calculation in theory, it can be found that the CO2 sequestration limitation degree for every kilogram steel slag is about 442 g when taking magne- sium into consideration, and the experimental CO2 sequestration degree for every kilogram slag is about 77 g, under the conditions that the liquid to solid ratio is 50 L/kg, CO2 flow is 0.5 L/min and the temperature of reaction is the ambient temperature. When solution NH4Cl and CHa COOH for experiments and other conditions keep the same, the actual potential CO2 sequestration for every kilogram slag is 69.3 g and 31.20 g respectively. Thus, optimization of process parameters like granularity of slag is necessary to enhance the carbon dioxide sequestration degree for steel slag.

  16. Flexural Strength of Carbon Fiber Reinforced Polymer Repaired Cracked Rectangular Hollow Section Steel Beams

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2015-01-01

    Full Text Available The flexural behavior of rectangular hollow section (RHS steel beams with initial crack strengthened externally with carbon fiber reinforced polymer (CFRP plates was studied. Eight specimens were tested under three-point loading to failure. The experimental program included three beams as control specimens and five beams strengthened with CFRP plates with or without prestressing. The load deflection curves were graphed and failure patterns were observed. The yield loads and ultimate loads with or without repairing were compared together with the strain distributions of the CFRP plate. It was concluded that yield loads of cracked beams could be enhanced with repairing. Meanwhile, the ultimate loads were increased to some extent. The effect of repair became significant with the increase of the initial crack depth. The failure patterns of the repaired specimens were similar to those of the control ones. Mechanical clamping at the CFRP plate ends was necessary to avoid premature peeling between the CFRP plate and the steel beam. The stress levels in CFRP plates were relatively low during the tests. The use of prestressing could improve the utilization efficiency of CFRP plates. It could be concluded that the patching repair could be used to restore the load bearing capacity of the deficient steel beams.

  17. A facile electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on carbon steel

    Science.gov (United States)

    Fan, Yi; He, Yi; Luo, Pingya; Chen, Xi; Liu, Bo

    2016-04-01

    Superhydrophobic Fe film with hierarchical micro/nano papillae structures is prepared on C45 steel surface by one-step electrochemical method. The superhydrophobic surface was measured with a water contact angle of 160.5 ± 0.5° and a sliding angle of 2 ± 0.5°. The morphology of the fabricated surface film was characterized by field emission scanning electron microscopy (FE-SEM), and the surface structure seems like accumulated hierarchical micro-nano scaled particles. Furthermore, according to the results of Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS), the chemical composition of surface film was iron complex with organic acid. Besides, the electrochemical measurements showed that the superhydrophobic surface improved the corrosion resistance of carbon steel in 3.5 wt.% NaCl solution significantly. The superhydrophobic layer can perform as a barrier and provide a stable air-liquid interface which inhibit penetration of corrosive medium. In addition, the as-prepared steel exhibited an excellent self-cleaning ability that was not favor to the accumulation of contaminants.

  18. Mass Transfer Coefficient During Cathodic Protectionof Low Carbon Steel in Seawater

    Directory of Open Access Journals (Sweden)

    Ameel Mohammed Rahman

    2009-01-01

    Full Text Available The aim of this research is to calculate mass transfer coefficient, kd, during cathodic protection of low carbon steel in neutral seawater (3.5% W/V NaCl in distilled water with pH = 7. Two types of cathodic protection were used:First: Sacrificial anode cathodic protection (SACP were a pipeline of steel carrying seawater using zinc as a sacrificial anode and with variable temperatures ranged (0 – 45oC and volumetric flow rate ranged (5 – 900 lit/hr. It was found that the kd increases with increasing temperature and volumetric flow rate of seawater, where kd ranged (0.24×10-6 – 41.6×10-6 m/s.Second: Impressed current cathodic protection (ICCP technique adopting a rotating vertical steel cylinder in seawater with variable temperatures ranged (0 – 45oC and rotating velocity ranged (0 – 400 rpm. It was found that the kd increases with increasing temperature and rotating velocity, where kd ranged (7.25×10-6 – 36.82×10-6 m/s.

  19. Effects of LWR coolant environments on fatigue design curves of carbon and low-alloy steels

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Shack, W.J. [Argonne National Lab., IL (United States)

    1998-03-01

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the code specify fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data indicate that the Code fatigue curves may not always be adequate in coolant environments. This report summarizes work performed by Argonne National Laboratory on fatigue of carbon and low-alloy steels in light water reactor (LWR) environments. The existing fatigue S-N data have been evaluated to establish the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, temperature, orientation, and sulfur content on the fatigue life of these steels. Statistical models have been developed for estimating the fatigue S-N curves as a function of material, loading, and environmental variables. The results have been used to estimate the probability of fatigue cracking of reactor components. The different methods for incorporating the effects of LWR coolant environments on the ASME Code fatigue design curves are presented.

  20. Study on laser welded heat-affected zone in new ultralow carbon bainitic steel

    Institute of Scientific and Technical Information of China (English)

    Lin Zhao; Wuzhu Chen; Xudong Zhang; Jiguo Shan

    2007-01-01

    800 MPa grade ultralow carbon bainitic (NULCB) steel is the recently developed new generation steel, which was produced by thermo mechanical controlled processing & relaxation-precipitation controlling transformation (TMCP&RPC) technique. The microstructure and the mechanical properties of the heat-affected zone (HAZ) in NULCB steel under laser welding conditions were investigated by using a Gleeble-1500 thermal simulator. The experimental results indicate that the simplex microstructure in the HAZ is granular bainite that consists of bainite-ferrite (BF) lath and M-A constituent when the cooling time from 800 to 500°C (t8/5) is 0.3-30 s, and the M-A constituent consists of twinned martensite and residual austenite. As t8/5 increases, the hardness and tensile strength of HAZ decreases, but they are higher than that of the base metal, indicating the absence of softened zone after laser welding. The impact toughness of HAZ increases at first and then decreases when tw increases. The impact energy of HAZ is much higher than that of the base metal when t8/5 is between 3 and 15 s. It indicates that excellent low temperature toughness can be obtained under appropriate laser welding conditions.

  1. Thermodynamic analysis of carbon migration in W1-1.0C steel in plasma surface chromizing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    W1-1.0C steel was chromized at 1173 K with double glow plasma surface alloying process, and the distribution of Fe, Cr,and C contents in the chromized layer was measured using glow discharge spectrum analysis (GDA).The behavior and mechanism of carbon migration during the formation of chromized layer were studied through thermodynamic analysis and calculation.The gradient of carbon chemical potential was regarded as the driving force of carbon migration.An equation was derived to describe the carbon content varying with the chromium content within the carbon-rich region.The calculated results from the equation approximated closely to the experimental ones.

  2. INVESTIGATION OF FRACTURE DESIGN FOR MEDIUM CARBON STEEL UNDER EXTRA-LOW CYCLIC FATIGUE IN AXIAL LOADING

    Institute of Scientific and Technical Information of China (English)

    Youtang Li; Shuai Tan; Hongyan Duan

    2008-01-01

    The extra-low cyclic fracture problem of medium carbon steel under axial fatigue loading was investigated.Several problems,such as the relations of the cycle times to the depth and tip radius of the notch,loading frequency,loading range and the parameters of fracture design for medium carbon steel on condition of extra-low axial fatigue loading were discussed based on the experiments.Experimental results indicated that the tension-pressure fatigue loading mode was suitable for extra-low cyclic fatigue fracture design of medium carbon steel and it resulted in low energy consumption,fracture surface with high quality,low cycle times,and high efficiency.The appropriate parameters were as follows:loading frequency 3-5 Hz,notch tip radius r=(0.2-0.3)mm,opening angle α=60°,and notch depth t=(0.14-0.17)D.

  3. Co-precipitation of copper and niobium carbide in a low carbon steel

    Science.gov (United States)

    Gagliano, Michael Scott

    Co-precipitation of niobium carbide and body-centered cubic (BCC) copper in ferrite was investigated as a high strength, low carbon, chromium-free alternative to conventional high performance structural steels that rely on a tempered martensitic microstructure. Theoretical nucleation and growth rate models for BCC copper and niobium carbide were constructed using calculated thermodynamic driving forces in conjunction with classical theories for the homogeneous nucleation and subsequent growth of coherent, spherical precipitates. The maximum calculated nucleation and growth rates for niobium carbide were found to be 1.0 x 106 nuclei/cm3s at 666°C and 1.0 nm/s at 836°C, respectively, for an austenitizing temperature of 1170°C. For BCC copper in ferrite, the maximum calculated nucleation and growth rates were determined to be 8.0 x 1015 nuclei/cm 3s at 612°C and 0.038 nm/s at 682°C, respectively, for all austenitizing temperatures. Three-dimensional atom probe (3DAP) microscopy revealed the presence of nano-scale BCC copper clusters in approximately the same number density predicted by the theoretical nucleation model. Using an experimentally determined "effective" activation energy for copper in iron, the normalized theoretical nucleation rate curve compared very well with the normalized hardness response after 5 minutes of aging and effectively described the experimental short-time aging behavior of a low carbon, niobium bearing steel. The size and morphological evolution as well as the growth and coarsening behavior of copper precipitates were investigated through conventional TEM during isothermal direct aging at 550°C for a niobium and niobium-free steel. Although niobium carbide precipitation was not characterized, niobium additions provided increased hardness upon direct aging and showed a much higher resistance to overaging, than a niobium-free steel, for long isothermal aging times. In both steels for aging times up to five hours, both 9R type and BCC

  4. Optimisation of the hot conditioning of carbon steel surfaces of primary heat transport system of Pressurized Heavy Water Reactors using electrochemical impedance spectroscopy

    Science.gov (United States)

    Kiran Kumar, M.; Gaonkar, Krishna; Ghosh, Swati; Kain, Vivekanand; Bojinov, Martin; Saario, Timo

    2010-06-01

    Hot conditioning operation of the primary heat transport system is an important step prior to the commissioning of Pressurized Heavy Water Reactors. One of the major objectives of the operation is to develop a stable and protective magnetite layer on the inner surfaces of carbon steel piping. The correlation between stable magnetite film growth on carbon steel surfaces and the period of exposure to hot conditioning environment is generally established by a combination of weight change measurements and microscopic/morphological observations of the specimens periodically removed during the operation. In the present study, electrochemical impedance spectroscopy (EIS) at room temperature is demonstrated as an alternate, quantitative technique to arrive at an optimal duration of the exposure period. Specimens of carbon steel were exposed for 24, 35 and 48 h during hot conditioning of primary heat transport system of two Indian PHWRs. The composition and morphology of oxide films grown during exposure was characterized by X-ray diffraction and optical microscopy. Further, ex situ electrochemical impedance spectra of magnetite films formed after each exposure were measured, in 1 ppm Li + electrolyte at room temperature as a function of potential in a range of -0.8 to +0.3 VSCE. The defect density of the magnetite films formed after each exposure was estimated by Mott-Schottky analysis of capacitances extracted from the impedance spectra. Further the ionic resistance of the oxide was also extracted from the impedance spectra. Defect density was observed to decrease with increase in exposure time and to saturate after 35 h, indicating stabilisation of the barrier layer part of the magnetite film. The values of the ionic transport resistance start to increase after 35-40 h of exposure. The quantitative ability of EIS technique to assess the film quality demonstrates that it can be used as a supplementary tool to the thickness and morphological characterizations of samples

  5. Optimisation of the hot conditioning of carbon steel surfaces of primary heat transport system of Pressurized Heavy Water Reactors using electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kiran Kumar, M., E-mail: mkiran@barc.gov.i [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Gaonkar, Krishna; Ghosh, Swati; Kain, Vivekanand [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Bojinov, Martin [Department of Physical Chemistry, University of Chemical Technology and Metallurgy, Kl. Ohridski Blvd. 8, 1756 Sofia (Bulgaria); Saario, Timo [VTT Materials and Building, VTT Technical Research Centre of Finland, P.O. Box 1000, Kemistintie 3, FIN-02044 VTT, Espoo (Finland)

    2010-06-15

    Hot conditioning operation of the primary heat transport system is an important step prior to the commissioning of Pressurized Heavy Water Reactors. One of the major objectives of the operation is to develop a stable and protective magnetite layer on the inner surfaces of carbon steel piping. The correlation between stable magnetite film growth on carbon steel surfaces and the period of exposure to hot conditioning environment is generally established by a combination of weight change measurements and microscopic/morphological observations of the specimens periodically removed during the operation. In the present study, electrochemical impedance spectroscopy (EIS) at room temperature is demonstrated as an alternate, quantitative technique to arrive at an optimal duration of the exposure period. Specimens of carbon steel were exposed for 24, 35 and 48 h during hot conditioning of primary heat transport system of two Indian PHWRs. The composition and morphology of oxide films grown during exposure was characterized by X-ray diffraction and optical microscopy. Further, ex situ electrochemical impedance spectra of magnetite films formed after each exposure were measured, in 1 ppm Li{sup +} electrolyte at room temperature as a function of potential in a range of -0.8 to +0.3 V{sub SCE}. The defect density of the magnetite films formed after each exposure was estimated by Mott-Schottky analysis of capacitances extracted from the impedance spectra. Further the ionic resistance of the oxide was also extracted from the impedance spectra. Defect density was observed to decrease with increase in exposure time and to saturate after 35 h, indicating stabilisation of the barrier layer part of the magnetite film. The values of the ionic transport resistance start to increase after 35-40 h of exposure. The quantitative ability of EIS technique to assess the film quality demonstrates that it can be used as a supplementary tool to the thickness and morphological characterizations of

  6. Methodology to make a robust estimation of the carbon steel overpack lifetime with respect to the Belgian Supercontainer design

    Science.gov (United States)

    Kursten, B.; Druyts, F.

    2008-09-01

    The Supercontainer (SC) design is the preferred Belgian option for the final disposal of vitrified high-level waste (VHLW) and spent fuel (SF) in deep underground clay layers. The SC consists of a carbon steel overpack, containing VHLW canisters or SF assemblies, surrounded by a thick concrete buffer, which in turn, is entirely encased in a stainless steel envelope. An integrated R&D strategy is developed to demonstrate and defend that the integrity of the carbon steel overpack can be ensured at least during the thermal phase. This integrated approach, proposed to estimate the lifetime of the carbon steel overpack, consists of three steps: lifetime prediction, validation, and confidence building. Under the predicted conditions within the SC (highly alkaline concrete buffer), the carbon steel overpack is expected to undergo uniform corrosion (passive dissolution). The methodology exists in demonstrating that corrosion forms other than uniform corrosion (e.g. localised corrosion such as pitting corrosion, crevice corrosion and stress corrosion cracking) cannot occur ('exclusion principle'). This paper elaborates on how this methodology is implemented.

  7. Passive film growth on carbon steel and its nanoscale features at various passivating potentials

    Science.gov (United States)

    Li, Yuan; Cheng, Y. Frank

    2017-02-01

    In this work, the passivation and topographic sub-structure of passive films on a carbon steel in a carbonate/bicarbonate solution was characterized by electrochemical measurements, atomic force microscopy and X-ray photoelectron spectroscopy. When passivating at a potential near the active-passive transition, the film contains the mixture of Fe3O4, Fe2O3 and FeOOH, with numerous nanoscale features. As the film-forming potential shifts positively, the passive film becomes more compact and the nanoscale features disappear. When the film is formed at a passive potential where the oxygen evolution is enabled, the content of FeOOH in the film increases, resulting in an amorphous topography and reduced corrosion resistance.

  8. Improvement of center segregation in high-carbon steel billets using soft reduction

    Institute of Scientific and Technical Information of China (English)

    Wenjun Wang; Xionggang Hu; Linxin Ning; Raimund Bülte; Wolfgang Bleck

    2006-01-01

    Center segregation is the main reason for cup fracture of high-carbon wire rod during drawing. Therefore, to continuously produce cast billets with very low center segregation is an important objective. The soft reduction technology is considered to be an effective method to minimize center segregation. To elucidate the effect of soft reduction on the internal quality of high-carbon steel billets, soft reduction was applied with different solid fractions in the core area of billets in a laboratory casting machine. A coupled temperature/displacement finite element model was developed to calculate the solid fraction using the commercial software ABAQUS.Center segregation, center porosity, homogeneity of elements, and equiaxed crystal zone were obviously improved by applying soft reduction, especially when the solid fraction was less than 1.0. The optimal results were obtained when the solid fraction was approximately 0.9.

  9. Processing of low carbon steel plate and hot strip—An overview

    Indian Academy of Sciences (India)

    B K Panigrahi

    2001-08-01

    Soaking temperature, drafting schedule, finish rolling and coiling temperatures all play important roles in processing of low carbon plate and strip. They control the kinetics of various physical and metallurgical processes, viz. austenitization, recrystallization and precipitation behaviour. The final transformed microstructures depend upon these processes and their interaction with each other. In view of increasing cost of input materials, new processing techniques such as recrystallized controlled rolling and warm rolling have been developed for production of plates and thinner hot bands with very good deep drawability respectively. Besides hybrid computer modelling is used for production of strip products with tailor made properties. Although there have been few reviews on low carbon microalloyed steels in the past the present one deals with new developments.

  10. 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.

  11. Ultrasonic characterization of defects. Part 4. Study of realistic flaws in welded carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Lingvall, F.; Stepinski, T. [Uppsala Univ. (Sweden). Signals and Systems

    1999-02-01

    This report treats the ultrasonic measurements performed on the new V-welded carbon steel blocks and development of the algorithms for feature extraction, flaw position estimation, etc. Totally 36 different defects, divided into 8 types, were manufactured and implanted into the V-welds in the steel blocks. The flaw population can also be divided in two major groups: sharp flaws (various types of cracks and lack of fusion) and soft types of flaws (slag, porosity and over penetration). A large amount of B- and D-scan measurements were performed on these flaws using 6 different transducers. The evaluation of these measurements resulted in the conclusion that the signal variation for the same type of defects is rather large compared to the variation found in signals from artificial and simulated defects. The steel block measurements also revealed that some of the defects were hard to distinguish, particularly if traditional features like fall/raise times, pulse duration and echo dynamics are used. To overcome this difficulty more powerful feature extraction methods were proposed, like the discrete wavelet transform and principal component analysis. Another important subject that is treated in this report is the estimation of flaw positions from B-scans. The previously used, one dimensional method, appeared to be sensitive to errors in the steel block measurements which, in some cases, resulted in poor flaw position estimates. Therefore, a two dimensional approach was proposed which should result in more robust estimates due to the larger amount of data that is used for the estimation.

  12. Effect of high heating and cooling rate on interface of diffusion bonded gray cast iron to medium carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, B. [Firat University, Technical Education Faculty, Metal Department, 23119 Elazig (Turkey); Orhan, N. [Firat University, Technical Education Faculty, Metal Department, 23119 Elazig (Turkey)]. E-mail: norhan@firat.edu.tr; Hascalik, A. [Firat University, Technical Education Faculty, Department of Manufacturing, Elazig (Turkey)

    2007-07-01

    In the present study, a gray cast iron and a medium carbon steel couple were diffusion bonded at the temperatures of 850, 900, 950 and 1000 deg. C under a pressure of 8 MPa for 30 min, and the effects of temperature and high heating and cooling rate on interface formations and microstructure were investigated. After diffusion bonding, scanning electron microscopy, shear test measurements and microhardness measurement of interface region were made. The microstructure at the inside of medium carbon steel of bonded couple consisted of martensite. As a result, from the microstructural observations, a good bonding along the interface of the bonded couples and the interface is free from voids and microcracks.

  13. NbC precipitates EELS spectra in a very low carbon microalloyed steel

    Directory of Open Access Journals (Sweden)

    Mancilla, J. E.

    2004-06-01

    Full Text Available In this paper a characterization study by transmission electron microscopy (TEM and electron energy loss spectroscopy (EELS of NbC precipitates in microalloyed steel is presented. The steel was hot rolled in a laboratory scale two-high reversing mill. The shape, size, location, and number of particles per unit area in the steel microstructure are reported. The particles were semi quantitatively analyzed for the heavier alloying elements using EDS, while EELS was used for the lighter elements, e. g. carbon and nitrogen. The EELS study of the precipitates reveals that the carbon is present as a compound (NbC without nitrogen.

    En este trabajo se presenta un estudio de caracterización por espectroscopia de pérdida de energía de electrones (EPEE realizado en un microscopio electrónico de transmisión de los precipitados de NbC en un acero microaleado. El acero se laminó en caliente en un laminador dúo reversible escala laboratorio. Las partículas de precipitados se caracterizaron en tamaños, formas y distribución y se analizaron semicuantitativamente para los elementos de aleación del acero más pesados, empleando un detector por dispersión de energías de rayos X, mientras que la EPEE se empleó para los elementos más ligeros, es decir, el carbono y el nitrógeno. El estudio por EPEE de los precipitados muestra que el carbono está presente como un compuesto (NbC sin que se haya encontrado nitrógeno en los mismos.

  14. Surface Roughness Prediction Model in Machining of Carbon Steel by PVD Coated Cutting Tools

    Directory of Open Access Journals (Sweden)

    Yusuf Sahin

    2004-01-01

    Full Text Available The surface roughness model in the turning of AISI 1040 carbon steel was developed in terms of cutting speed, feed rate and depth of cut using response surface methodology. Machining tests were carried out using PVD-coated tools under different cutting conditions. The surface roughness equations of cutting tools when machining the carbon steels were achieved by using the experimental data. The results are presented in terms of mean values and confidence levels. The established equation shows that the feed rate was found to be a main influencing factor on the surface roughness. It increased with increasing the feed rate, but decreased with increasing the cutting speed and the depth of cut, respectively. The variance analysis for the second-order model shows that the interaction terms and the square terms were statically insignificant. However, it could be seen that the first-order effect of feed rate was significant while cutting speed and depth of cut was insignificant. The predicted surface roughness of the samples was found to lie close to that of the experimentally observed ones with 95% confident intervals.

  15. Experimental Study on Vacuum Carburizing Process for Low-Carbon Alloy Steel

    Science.gov (United States)

    Wei, Shaopeng; Wang, Gang; Zhao, Xianhui; Zhang, Xiaopeng; Rong, Yiming

    2013-10-01

    As a low-carbon alloy steel, 20Cr2Ni4A steel has an excellent mechanical properties. It has been used for producing heavy-duty gears, which require good wear and fatigue resistance. The vacuum carburizing process can improve the quality of gears and extend the service life. In this article, a complete heat-treatment process for 20Cr2Ni4A, with carburizing, tempering, quenching and cryogenic steps involved, was proposed. A numerical method was employed to design the carburizing step. The carburized samples were characterized by analysis of carbon profile, surface-retained austenite content, microstructure, and hardness profile. A good microstructure was obtained with acicular-tempered martensite, less-retained austenite, fine granular-dispersed carbides, and was oxide free. The final surface hardness was 64.2HRC, and the case depth was 0.86 mm, which meet the requirements of products. The relationships among process, performance, and microstructure were investigated to understand the inner connection.

  16. Development of Fractal Dimension and Characteristic Roughness Models for Turned Surface of Carbon Steels

    Science.gov (United States)

    Zuo, Xue; Zhu, Hua; Zhou, Yuankai; Ding, Cong; Sun, Guodong

    2016-08-01

    Relationships between material hardness, turning parameters (spindle speed and feed rate) and surface parameters (surface roughness Ra, fractal dimension D and characteristic roughness τ∗) are studied and modeled using response surface methodology (RSM). The experiments are carried out on a CNC lathe for six carbon steel material AISI 1010, AISI 1020, AISI 1030, AISI 1045, AISI 1050 and AISI 1060. The profile of turned surface and the surface roughness value are measured by a JB-5C profilometer. Based on the profile data, D and τ∗ are computed through the root-mean-square method. The analysis of variance (ANOVA) reveals that spindle speed is the most significant factors affecting Ra, while material hardness is the most dominant parameter affecting τ∗. Material hardness and spindle speed have the same influence on D. Feed rate has less effect on three surface parameters than spindle speed and material hardness. The second-order models of RSM are established for estimating Ra, D and τ∗. The validity of the developed models is approximately 80%. The response surfaces show that a surface with small Ra and large D and τ∗ can be obtained by selecting a high speed and a large hardness material. According to the established models, Ra, D and τ∗ of six carbon steels surfaces can be predicted under cutting conditions studied in this paper. The results have an instructive meaning to estimate the surface quality before turning.

  17. ACCIDENTAL DROP OF A CARBON STEEL/LEAD SHIPPING CASK AT LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    B. D. Hawkes; K. R. Durstine

    2007-07-01

    A shielded cask is used to transport radioactive materials between facilities. The cask was fabricated with an outer and inner shell of hot rolled low carbon steel. Lead was poured in the annular space between the shells to provide radiation shielding. Carbon steel is known to be susceptible to lowtemperature brittle fracture under impact loading. This paper will present the analysis results representing postulated transportation accidents during on-site transfers of the cask. The accident scenarios were based on a series of cask drops onto a rigid surface from a height of 6 ft assuming brittle failure of the cask shell at subzero temperatures. Finite element models of the cask and its contents were solved and post processed using ABAQUS software. Each model was examined for failure to contain radioactive materials and/or significant loss of radiation shielding. Results of these analyses show that the body of the cask exhibits considerable ruggedness and will remain largely intact after the impact. There will be deformation of the main cask body with localized brittle failure of the cask outer shell and components and but no complete penetration of the cask shielding. The cask payload outer waste can will experience some permanent plastic deformation in each drop, but will not be deformed to the point where it will rupture, thus maintaining confinement of the can contents.

  18. Accidental Drop of a Carbon Steel/Lead Shipping Cask (HFEF 14) at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Brian D. Hawkes; Michael E. Nitzel

    2007-08-01

    A shielded cask is used to transport radioactive materials between facilities at the Idaho National Laboratory. The cask was fabricated with an outer and inner shell of A36 carbon steel with lead poured in the annular space between the shells to provide radiation shielding. Carbon steel is known to be susceptible to low-temperature brittle fracture under impact loading. This paper will present the analysis results representing postulated transportation accidents during on-site transfers of the cask at subzero temperatures. The accident scenarios were based on a series of cask drops onto a rigid surface from a height of 1.83m (6 ft.) Finite element models of the cask and its contents were solved and post processed using the ABAQUS software. Each model was examined for failure to contain radioactive materials and/or significant loss of radiation shielding. Results of these analyses show that the body of the cask exhibits considerable ruggedness and will remain largely intact after the impact. There will be deformation of the main cask body with localized brittle failure of the cask outer shell and door structure. The cask payload outer waste can remains in the cask but will experience some permanent plastic deformation in each drop. It will not be deformed to the point where it will rupture, thus maintaining confinement of the can contents.

  19. Study of the Deburring Process for Low Carbon Steel by Plasma Electrolytic Oxidation

    Science.gov (United States)

    Li, Hongtao; Kan, Jinfeng; Jiang, Bailing; Liu, Yanjie; Liu, Zheng

    2016-08-01

    In an appropriate electrochemical environment, the discrete thermal electron emission could be induced in the micro area due to the uneven distribution of electron flux on the anode surface. Thus an oxygen molecule could be ionized at the liquid-solid interface after collision, and then oxygen plasma with distribution characteristics would be formed. The plasma electrolytic oxidation (PEO) could happen at the liquid-solid interface. In this work, the low carbon steel was used to study the deburring process by PEO at a high frequency (70000 Hz) pulse DC mode. Its burr height H from 3.23 mm to 0.04 mm was removed to form a smooth surface within 6 min. The values of corrosion potential and current density for the untreated sample were -0.667 V and 6.735×10-5 A/cm2, respectively. But for the treated sample, the corrosion potential and current density were relatively lower, -0.354 V and 1.19×10-7 A/cm2. Therefore, PEO was expected to be a new deburring method of carbon steel for the material processing field. supported by National Natural Science Foundation of China (No. 51571114) and Natural Science Foundation of Jiangsu Province, China (No. BK20130935)

  20. Effect of Niobium and Titanium on Dynamic Recrystallization Behavior of Low Carbon Steels

    Institute of Scientific and Technical Information of China (English)

    MA Li-qiang; LIU Zhen-yu; JIAO Si-hai; YUAN Xiang-qian; WU Di

    2008-01-01

    Using a Gleeble 3800 thermo-mechanical simulator, the effect of niobium and titanium on the dynamic re-crystallization (DRX) behavior of low carbon steels was investigated. Isothermal single compression tests were per-formed in the temperature range of 850 to 1 150 ℃ at eonatant strain rates of 0. 1 to 5 s-1. The experimental results showed that the addition of niobium and titanium to the low carbon steels significantly increased both the peak stress and steady state stress. The activation energy of deformation Qd was larger than the activation energy associated with the steady state stress Qss. Furthermore, the difference between Qd and Qss became significant because of the addition of niobium and titanium. DRX is effeetively retarded beeause of solute dragging and dynamic precipitate pinning of niobium and titanium, resulting in higher values of the peak strain and steady state strain. Finally, the influence of niobium and titanium on the DRX kinetics and steady state grain size was determined.

  1. Influence of severe plastic deformation on the structure and properties of ultrahigh carbon steel wire

    Energy Technology Data Exchange (ETDEWEB)

    Leseur, D R; Sherby, O D; Syn, C K

    1999-07-01

    Ultrahigh-carbon steel wire can achieve very high strength after severe plastic deformation, because of the fine, stable substructures produce. Tensile strengths approaching 6000 MPa are predicted for UHCS containing 1.8%C. This paper discusses the microstructural evolution during drawing of UHCS wire, the resulting strength produced and the factors influencing fracture. Drawing produces considerable alignment of the pearlite plates. Dislocation cells develop within the ferrite plates and, with increasing strain, the size normal to the axis ({lambda}) decreases. These dislocation cells resist dynamic recovery during wire drawing and thus extremely fine substructures can be developed ({lambda} < 10 nm). Increasing the carbon content reduces the mean free ferrite path in the as-patented wire and the cell size developed during drawing. For UHCS, the strength varies as {lambda}{sup {minus}5}. Fracture of these steels was found to be a function of carbide size and composition. The influence of processing and composition on achieving high strength in these wires during severe plastic deformation is discussed.

  2. CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.; Mickalonis, J.; Subramanian, K.; Ketusky, E.

    2011-10-14

    Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.

  3. Effect of chloride content of molten nitrate salt on corrosion of A516 carbon steel.

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, Robert W.; Clift, W. Miles

    2010-11-01

    The corrosion behavior of A516 carbon steel was evaluated to determine the effect of the dissolved chloride content in molten binary Solar Salt. Corrosion tests were conducted in a molten salt consisting of a 60-40 weight ratio of NaNO{sub 3} and KNO{sub 3} at 400{sup o}C and 450{sup o}C for up to 800 hours. Chloride concentrations of 0, 0.5 and 1.0 wt.% were investigated to determine the effect on corrosion of this impurity, which can be present in comparable amounts in commercial grades of the constituent salts. Corrosion rates were determined by descaled weight losses, corrosion morphology was examined by metallographic sectioning, and the types of corrosion products were determined by x-ray diffraction. Corrosion proceeded by uniform surface scaling and no pitting or intergranular corrosion was observed. Corrosion rates increased significantly as the concentration of dissolved chloride in the molten salt increased. The adherence of surface scales, and thus their protective properties, was degraded by dissolved chloride, fostering more rapid corrosion. Magnetite was the only corrosion product formed on the carbon steel specimens, regardless of chloride content or temperature.

  4. Absorption of metals in mulloway (Argyrosomus japonicus) after ingesting nickel-plated carbon-steel hooks.

    Science.gov (United States)

    McGrath, Shane P; Reichelt-Brushett, Amanda J; Butcher, Paul A; Cairns, Stuart C

    2014-08-01

    Previous research has alluded to the potential of metals being absorbed by fish after ingesting fishing hooks, which may have adverse effects on fish health and the organisms that consume them. Subsequently, this study aimed to quantify the potential of mulloway (Argyrosomus japonicus) to absorb metals during the decay of ingested nickel-plated carbon-steel hooks. Twenty-five treatment fish were allowed to ingest nickel-plated carbon-steel hooks during angling and then monitored with 25 controls (untreated fish) for up to 42 days for hook ejection and mortality. Blood, liver and muscle samples were collected from treatment, control and 14 wild-caught individuals to determine the concentrations of chromium, cobalt, copper, iron, manganese and nickel. The results showed that increased oxidation influenced hook ejection, and that hook-ingested fish had significantly elevated concentrations of nickel in their liver and blood, but not muscle. This research has shown that there is an avenue for metal absorption from ingested hooks.

  5. Influence of explosive welding parameters on properties of bimetal Ti-carbon steel

    Directory of Open Access Journals (Sweden)

    Prazmowski Mariusz

    2017-01-01

    Full Text Available Explosion welding of metals is a process of great technological significance in terms of modern metal composites manufacturing possibilities Nevertheless, selecting welding parameters is not an easy task. This paper assesses the effect of various values of distance of sheets on the quality of the bond zone in titanium (Ti Gr.1 - carbon steel (P355GH structure. The research was carried out for initial state bonds i.e. immediately following explosion welding. The results of mechanical and structural investigations were presented. In order to determine changes in the value of strengthening, microhardness tests of both the weld and the joined plates were performed. Performed metallographic analysis shows that the standoff distance affects the quality of the bond zone boundary. Smaller distance promotes the formation of waves with lower parameters (of length and height, whereas greater distances allow forming the bond of a more pronounced, repetitive wavy character, however, increasing the quantity of the fusion zone at the same time. Also, the initial distance between the materials to be joined makes for the strengthening in the areas adjacent to bond boundary. The results received allowed to conclude that for the assumed parameters it is possible to obtain Ti -carbon steel bi-metal with properties meeting the standard’s requirements.

  6. Characterizations of Dynamic Strain-induced Transformation in Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Luhan Hao; Mingyue Sun; Namin Xiao; Dianzhong Li

    2012-01-01

    Dynamic strain-induced transformation of the low carbon steel Q(235) at 770℃ and 850℃ leads to fine ferrite grains. The microstructure characterization and mechanism of the fine ferrite grain were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) technique. The results show that strain-induced microstructure is the mixed microstructure of ferrite and pearlite, with cementite randomly distributed on ferrite grain boundaries and the grains interiors. EBSD images of grain boundaries demonstrate that high angle grain boundaries (HAGBs) are dominant in both of the deformation induced microstructures occurring below and above A(e3) , with only a few low angle grain boundaries (LAGBs) existing in the grain interiors. It implies that the dynamic strain-induced transformation (DSIT) happens above and below A(e3) temperature and has the same phase transition mechanisms. The refinement of ferrite is the cooperative effect of DSIT and continuous dynamic recrystallization (CDRX) of ferrite. Besides, DSIT is deemed as an incomplete carbon diffusion phase transition through the analysis of microstructure and the previous simulated results. The strengths of the Q(235) steel with refined ferrite and pearlite structure get doubled than the initial state without treated by DSIT and the residual stress in the refined structure is partly responsible for the ductility loss.

  7. Effects of carbon percentage, Stelmor cooling rate and laying head temperature on tensile strength gain in low carbon steels

    Science.gov (United States)

    Gade, Surya Prakash

    Low carbon steel wire rods are used to produce finished products such as fine wire, coat hangers, staples, and roofing nails. These products are subjected to excessively high work hardening rates during wire drawing process resulting in a variation in wire tensile strength. This research analyzes the effects of carbon percentage, StelmorRTM cooling rate and laying head temperature on the tensile strength gain in wire drawn low carbon steels using design of experiments. The probable reasons for variations in tensile strength gain are analyzed by observing the microstructural changes during experiments. Microstructural analysis was done extensively using optical microscope and Transmission Electron Microscope (TEM) and it was found that the tensile strength gain variation is mainly caused by the increase in the dislocation density in wire rod and wire due to high cooling rate and high laying head temperature, within the range considered. This research concludes that a low carbon wire rod can be produced with minimum tensile strength gain, lower dislocation density and finer ferrite grain size by maintaining a low cooling rate in the StelmorRTM cooling zone and low laying head temperature, which is the temperature at which the wire rod coils are laid on the Stelmor RTM deck. It is also concluded from the results of the present study that: (1) The lowest tensile strength gain is for NS 1006T-3 (0.07 wt.% Carbon) with low cooling rate of 14°F/s and low laying head temperature of 1500°F. (2) The highest tensile strength gain is for NS 1006T-3 with high cooling rate of 26°F/s and high laying head temperature of 1650°F. (3) The effect of StelmorRTM cooling rate and laying head temperature and their interaction are found to be the significant factors causing the variation in wire tensile strength gain. The StelmorRTM cooling rate has the most significant effect on tensile strength gain among the three factors. (4) The effect of carbon percentage on wire tensile strength

  8. Sour and sweet corrosion of carbon steel : general or pitting or localized or all of the above?

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S.; Doiron, A.; Li, J.; Park, D.Y.; Liu, P. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2009-07-01

    Carbon steel is used for 80 per cent of all refinery components in refineries, petrochemical plants and oil and gas pipelines. This paper described a model designed to predict internal pitting corrosion of carbon steel in sour and sweet environments. The effects of temperature and partial pressure of carbon dioxide (CO{sub 2}) were investigated experimentally using scanning electron microscopy (SEM) and laser profilometer analyses. Eight carbon steel coupons were placed in a high temperature high pressure rotating cage system. An autoclave was charged with CO{sub 2} and methane. Coupons were then examined using SEM and energy dispersive spectroscopy (EDS). Pit depth and density were evaluated. The obtained data were then filtered using a Gaussian filter to minimize scattering. The study showed that mass loss increased almost linearly as a function of CO{sub 2} partial pressure. An analysis of the surface layers indicated that a compact layer did not form to protect the surface from corrosion. Classical pitting corrosion processes were discussed, and the characteristics of carbon steel corrosion were outlined. 23 refs., 2 tabs., 12 figs.

  9. Erosion and Corrosion of Mild Steel and Stainless Steel in Sodium Carbonate/Bicarbonate Solution Bearing Alumina Particle

    Institute of Scientific and Technical Information of China (English)

    YUAN Qing-long; LIANG Hong-da

    2004-01-01

    With a rotating cylinder electrode apparatus, the polarization behaviors of the mild steel and the stainless steel 0Cr18Ni9 in NaHCO3 (0.5 M)+Na2CO3 (0.5 M) solution with and without erodent particles were investigated and compared. The results show that the rotation speed of cylinder hardly affects the polarization behavior of sample in solution without particles but exerts a great influence on that with particles. Increasing rotation speed, the free corrosion potential shifts to positive direction and the oxygen limiting current density increases. Both the mild steel and stainless steel 0Cr18Ni9 experience a significant increase of the mass loss by increasing erosion, and erosive wear was dominated by severe micro-plowing. The insufficient mechanical strength of both materials leads to a low resistance to particle removal. Increasing peripheral velocities of the rotating cylinder enhances the corrosion rate of the mild steel. The stainless steel 0Cr18Ni9, due to a high erosive wear, also suffers from similar erosion-corrosion damage, despite that its corrosion resistance is much higher than that of the mild steel.

  10. The extrinsic influence of carbon fibre reinforced plastic laminates to strengthen steel structures

    Indian Academy of Sciences (India)

    A K Patnaik; C L Bauer; T S Srivatsan

    2008-06-01

    The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and discussed in this paper were obtained by closely studying the behaviour of steel beams strengthened with carbon FRP material. An attempt is made to succinctly summarise the findings for two different types of strengthening of the steel beams using carbon FRP laminates. The first type of beams focuses on enhancing the strength of steel in flexure while the second focuses on increasing the shear strength of the beams. Three beams were designed so as to cause them to fail in flexure. Of the beams studied, two were strengthened using carbon FRP strips attached to the tension flange. One of the beams was tested to facilitate comparison of their behaviour to the two beams which are strengthened in flexure. Three other beams were designed such that they failed predominantly in shear. Of these three, two were strengthened with carbon FRP strips attached to the webs while the third beam was used as a control beam for the purpose of drawing comparisons. Preliminary results revealed a noticeable increase in the strength for both the flexure strengthened beams and the beams strengthened in shear. The observed increase in shear strength of the beams was 26% while the increase in strength for the beams tested in flexure was 15%. This study convincingly shows that it is possible to strengthen steel beams using carbon FRP laminates in both flexure and in shear.

  11. Emerging Energy-efficiency and Carbon Dioxide Emissions-reduction Technologies for the Iron and Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept.. China Energy Group; Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept.. China Energy Group; Arens, Marlene [Fraunhofer Inst. for Systems and Innovation Research (ISI), Karlsruhe (Germany)

    2013-01-31

    Iron and steel manufacturing is among the most energy-intensive industries and accounts for the largest share, approximately 27 percent, of global carbon dioxide (CO2) emissions from the manufacturing sector. The ongoing increase in world steel demand means that this industry’s energy use and CO2 emissions continue to grow, so there is significant incentive to develop, commercialize and adopt emerging energy-efficiency and CO2 emissions-reduction technologies for steel production. Although studies from around the world have identified a wide range of energy-efficiency technologies applicable to the steel industry that have already been commercialized, information is limited and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on 56 emerging iron and steel industry technologies, with the intent of providing a well-structured database of information on these technologies for engineers, researchers, investors, steel companies, policy makers, and other interested parties. For each technology included, we provide information on energy savings and environmental and other benefits, costs, and commercialization status; we also identify references for more information.

  12. Decomposition analysis of energy-related carbon dioxide emissions in the iron and steel industry in China

    Institute of Scientific and Technical Information of China (English)

    Wenqiang SUN; Jiuju CAI, Hai YU, Lei DAI

    2012-01-01

    This work aims to identify the main factors influencing the energy-related carbon dioxide (CO2) emissions from the iron and steel industry in China during the period of 1995-2007. The logarithmic mean divisia index (LMDI) technique was applied with period-wise analysis and time-series analysis. Changes in energy- related CO2 emissions were decomposed into four factors: emission factor effect, energy structure effect, energy consumption effect, and the steel production effect. The results show that steel production is the major factor responsible for the rise in CO2 emissions during the sampling period; on the other hand the energy consump- tion is the largest contributor to the decrease in C02 emissions. To a lesser extent, the emission factor and energy structure effects have both negative and positive contributions to C02 emissions, respectively. Policy implications are provided regarding the reduction of C02 emissions from the iron and steel industry in China, such as controlling the overgrowth of steel production, improving energy-saving technologies, and introducing low-carbon energy sources into the iron and steel industry.

  13. Rate of formation of carboxyhemoglobin in exercising humans exposed to carbon monoxide.

    Science.gov (United States)

    Tikuisis, P; Kane, D M; McLellan, T M; Buick, F; Fairburn, S M

    1992-04-01

    The purpose of this study was to test the CFK equation for its prediction of the rate of formation of carboxyhemoglobin (HbCO) in exercising humans by use of measured values of the respiratory variables and to characterize the rate of appearance of HbCO with frequent blood sampling. Ten nonsmoking male subjects were exposed to carbon monoxide (CO) on two separate occasions distinguished by the level of activity. Steady-state exercise was conducted on a cycle ergometer at either a low (approximately 45 W) or moderate (approximately 90 W) power output. Each experiment began with an exposure of 3,000 ppm CO for 3 min during a rest period followed by three intermittent exposures ranging from 3,000 ppm CO for 1 min at low exercise to 667 ppm CO for 3 min at moderate exercise. Increases in HbCO were normalized against predicted values to account for individual differences in the variables that govern CO uptake. No difference in the normalized uptake of CO was found between the low- and moderate-exercise trials. However, the CFK equation underpredicted the increase in HbCO for the exposures at rest and the first exposure at exercise, whereas it overpredicted for the latter two exposures at exercise. The net increase in HbCO after all exposures (approximately 10% HbCO) deviated by less than 1% HbCO between the measured and predicted values. The rate of appearance of HbCO fits a sigmoidal shape with considerable overshoot at the end of exposure. This can be explained by delays in the delivery of CO to the blood sampling point (dorsal hand vein) and by a relatively small blood circulation time compared with other regions of the body. A simple circulation model is used to demonstrate the overshoot phenomenon.

  14. Rate of formation of carboxyhemoglobin in exercising humans exposed to carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Tikuisis, P.; Kane, D.M.; McLellan, T.M.; Buick, F.; Fairburn, S.M. (Defence and Civil Institute of Environmental Medicine, North York, Ontario (Canada))

    1992-04-01

    The purpose of this study was to test the CFK equation for its prediction of the rate of formation of carboxyhemoglobin (HbCO) in exercising humans by use of measured values of the respiratory variables and to characterize the rate of appearance of HbCO with frequent blood sampling. Ten nonsmoking male subjects were exposed to carbon monoxide (CO) on two separate occasions distinguished by the level of activity. Steady-state exercise was conducted on a cycle ergometer at either a low ([approximately]45 W) or moderate ([approximately]90W) power output. Each experiment began with an exposure of 3,000 ppm CO for 3 min during a rest period followed by three intermittent exposures ranging from 3,000 ppm CO for 1 min at low exercise to 667 ppm CO for 3 min at moderate exercise. Increases in HbCO were normalized against predicted values to account for individual differences in the variables that govern CO uptake. No difference in the normalized uptake of CO was found between the low-and moderate-exercise trials. However, the CFK equation underpredicted the increase in HbCO for the exposures at rest and the first exposure at exercise, whereas it overpredicted for the latter two exposures at exercise. The net increase in HbCO after all exposures ([approximately]10% HbCO) deviated by <1% HbCO between the measured and predicted values. The rate of appearance of HbCO fits a sigmoidal shape with considerable overshoot at the end of exposure. This can be explained by delays in the delivery of CO to the blood sampling point (dorsal hand vein) and by a relatively small blood circulation time compared with other regions of the body. A simple circulation model is used to demonstrate the overshoot phenomenon. 26 refs., 6 figs., 1 tab.

  15. Characterization of dual-phase steel microstructure by combined submicrometer EBSD and EPMA carbon measurements.

    Science.gov (United States)

    Pinard, Philippe T; Schwedt, Alexander; Ramazani, Ali; Prahl, Ulrich; Richter, Silvia

    2013-08-01

    Electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) measurements are combined to characterize an industrial produced dual-phase steel containing some bainite fraction. High-resolution carbon mappings acquired on a field emission electron microprobe are utilized to validate and improve the identification of the constituents (ferrite, martensite, and bainite) performed by EBSD using the image quality and kernel average misorientation. The combination eliminates the ambiguity between the identification of bainite and transformation-induced dislocation zones, encountered if only the kernel average misorientation is considered. The detection of carbon in high misorientation regions confirms the presence of bainite. These results are corroborated by secondary electron images after nital etching. Limitations of this combined method due to differences between the spatial resolution of EBSD and EPMA are assessed. Moreover, a quantification procedure adapted to carbon analysis is presented and used to measure the carbon concentration in martensite and bainite on a submicrometer scale. From measurements on reference materials, this method gives an accuracy of 0.02 wt% C and a precision better than 0.05 wt% C despite unavoidable effects of hydrocarbon contamination.

  16. Electrochemical Impedance Spectroscopy Study on Corrosion Protection of Acrylate Nanocomposite on Mild Steel Doped Carbon Nanotubes

    Science.gov (United States)

    Mahmud, M. R.; Akhir, M. M.; Shamsudin, M. S.; Afaah, A. N.; Aadila, A.; Asib, N. A. M.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Harun, M. K.; Rusop, M.; Abdullah, S.

    2015-05-01

    Acrylate:carbon nanotubes (A:CNTs) nanocomposite thin film was prepared by sol- gel technique. The corrosion coating protection of acrylate:carbon nanotubes (CNTs) nanocomposite thin film has been coated on mild steel characterised by electrochemical impedance spectrometer (EIS) measurement and equivalent circuit model are employed to analyse coating impedance for corrosion protection. In this study, 3.5 w/v % sodium chloride (NaCl) solution was immersed the acrylate:carbon nanotubes nanocomposite thin film. As the results, the surface morphology were found that there formation of carbon nanotubes with good distribution on acrylate-based coating. From EIS measurement, A:CNTs nanocomposite thin film with 0.4 w/v % contain of CNTs was exhibited the highest coating impedance from Nyquist graph after immersed in sodium chloride solution and may provide the excellent corrosion protection. The Bode plots have shown the impedance is high at the beginning from the time at high frequency and slightly decreases with value of frequency become smaller.

  17. The adsorption and inhibition effect of calcium lignosulfonate on Q235 carbon steel in simulated concrete pore solution

    Science.gov (United States)

    Wang, Yishan; Zuo, Yu; Zhao, Xuhui; Zha, Shanshan

    2016-08-01

    The corrosion inhibition of calcium lignosulfonate (CLS) for Q235 carbon steel in saturated Ca(OH)2 + 0.1 mol/L NaCl solution was studied by means of weight loss, polarization, fluorescence microscopy (FM), scanning electron microscopy/energy dispersive spectrometry (SEM/EDS), microscopic infrared spectral imaging (M-IR) and X-ray photoelectron spectroscopy (XPS). For the steel in simulated concrete pore solution (pH 12.6), an increase of Eb value and a decrease of icorr value occurred with different concentrations of CLS. The optimal content of CLS was 0.001 mol/L at which the inhibition rate was 98.86% and the Eb value increased to 719 mV after 10 h of immersion. In mortar solution and in reinforced concrete environment, CLS also showed good inhibition for steel. The preferential adsorption of CLS around pits was detected by M-IR. The result illustrates that at the early stage the adsorption of CLS was heterogeneous and CLS may have a competitive adsorption with chloride ions at the active sites, which would be beneficial for decreasing the susceptibility of pitting corrosion. After the pre-filming time, an intact adsorption CLS film formed on carbon steel surface. The adsorption between CLS and calcium presented as Casbnd Osbnd S bonds. The adsorption of CLS on carbon steel surface occurred probably by both physisorption and chemisorption.

  18. 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.

  19. The evolution of ultrahigh carbon steels - from the Great Pyramids, to Alexander the Great, to Y2K

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J

    1999-10-01

    Hypereutectoid steels containing between about 1 and 2.1 wt%C, and now known as ultrahigh carbon steels (UHCS), have both a rich history (dating back to the time of Alexander the Great, i.e. {approximately} 300 BC) and an interesting, recent, technological period of development (from 1975 to the present). The connections between the modern UHCS and their ancient counterparts, and in particular Damascus steels, have received considerable attention. In addition to monolithic products, UHCS have also been used in both ancient and modern times in laminated composites. In the present paper, a summary of the modern development of UHCS and UHCS-containing laminates is given, and parallels are drawn with ancient materials. Also, ancient laminated composites containing other steels are described; controversial issues and a possible solution related to the age of such a laminate found in the Great Pyramid of Gizeh are discussed.

  20. A Conceptual Model for the Interaction between Carbon Content and Manganese Sulphide Inclusions in the Short-Term Seawater Corrosion of Low Carbon Steel

    Directory of Open Access Journals (Sweden)

    Robert E. Melchers

    2016-05-01

    Full Text Available The critical role of manganese sulphide (MnS inclusions for the initiation of the short-term growth of pitting or localized corrosion of low carbon steels has long been recognized. Classical results show that pitting probability and pitting severity increases with increased sulphide concentration for low carbon steels as a result of magnesium sulphides acting as local cathodes for initiating pitting corrosion. However, the iron carbides (cementite in steels can also act as local cathodes for initiation of pitting corrosion. Herein it is proposed that there is competition between pits for cathodic area and that this will determine the severity of pitting and general corrosion observed in extended exposures. Preliminary experimental data for immersion exposures of up to 56 days in natural seawater of three low carbon steels show, contrary to conventional wisdom, greater pit depths for the steels with lower S content. However, the pit depth results are consistent with lower C/S ratios. This is considered to support the concept of cathodic competition between C and S. It is proposed that this offers explanations for a number of other phenomena, including the thus far unexplained apparently higher reactivity of some MnS inclusions.

  1. Blister formation on 13Cr2MoNbVB ferritic-martensitic steel exposed to hydrogen plasma

    Science.gov (United States)

    Nikitin, A. V.; Tolstolutskaya, G. D.; Ruzhytskyi, V. V.; Voyevodin, V. N.; Kopanets, I. E.; Karpov, S. A.; Vasilenko, R. L.; Garner, F. A.

    2016-09-01

    The influence of pre-irradiation specimen deformation level on surface blister formation and sub-surface cracking of dual-phase 13Cr2MoNbVB ferritic-martensitic steel was studied using glow discharge hydrogen plasma with ion energy of 1 keV to fluences of 2 × 1025 H/m2. Protium was used for most studies, but deuterium was used for measuring the depth dependence of hydrogen diffusion. Formation of blisters was observed in the temperature range 230-340 K. It was found that pre-irradiation deformation caused changes in the threshold fluences of blister formation and also in blister size distribution. Subsurface cracks located on grain boundaries far beyond the implantation zone were formed concurrently with blisters, arising from hydrogen diffusion and trapping at defects. It was observed that cracks as long as 1 mm in length were formed in 95% deformed steel at depths up to 500 μm from surface.

  2. Effects of iron-reducing bacteria on carbon steel corrosion induced by thermophilic sulfate-reducing consortia.

    Science.gov (United States)

    Valencia-Cantero, Eduardo; Peña-Cabriales, Juan José

    2014-02-28

    Four thermophilic bacterial species, including the iron-reducing bacterium Geobacillus sp. G2 and the sulfate-reducing bacterium Desulfotomaculum sp. SRB-M, were employed to integrate a bacterial consortium. A second consortium was integrated with the same bacteria, except for Geobacillus sp. G2. Carbon steel coupons were subjected to batch cultures of both consortia. The corrosion induced by the complete consortium was 10 times higher than that induced by the second consortium, and the ferrous ion concentration was consistently higher in iron-reducing consortia. Scanning electronic microscopy analysis of the carbon steel surface showed mineral films colonized by bacteria. The complete consortium caused profuse fracturing of the mineral film, whereas the non-iron-reducing consortium did not generate fractures. These data show that the iron-reducing activity of Geobacillus sp. G2 promotes fracturing of mineral films, thereby increasing steel corrosion.

  3. Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

    2015-09-01

    The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

  4. Comparison of CaCO3 from Natural Sources and Artificial Carbonates as Activators of Solid-Phase Carburizing of Low-Carbon Steel

    Science.gov (United States)

    González-Angeles, A.; López-Cuevas, J.; Pitalúa-Díaz, N.

    2013-11-01

    The process of solid-phase carburizing of steel with the use of carbonates of different origin including chemical reagents, limestone and oyster shells is studied. The highest microhardness is obtained in the case of SrCO3, wheres Na2CO3 is shown to be the cheapest and most economically expedient carbonate. A good carburized layer can be obtained using a mixture of limestone and oyster shells.

  5. Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Buchweishaija, Joseph

    1997-12-31

    Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

  6. 77 FR 25404 - Certain Hot-Rolled Carbon Steel Flat Products From India: Rescission of Antidumping Duty...

    Science.gov (United States)

    2012-04-30

    ... International Trade Administration Certain Hot-Rolled Carbon Steel Flat Products From India: Rescission of... products from India for the period December 1, 2010, through November 30, 2011. See Antidumping or... India: Customs and Border Protection Data for Selection of Respondents for Individual Review,''...

  7. 75 FR 1495 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Results of Countervailing...

    Science.gov (United States)

    2010-01-11

    ... Countervailing Duty Orders: Certain Hot-Rolled Carbon Steel Flat Products From India and Indonesia, 66 FR 60198... Division of Reserve Bank of India (RBI) provides short-term pre- shipment export financing, or ``packing credits,'' to exporters through commercial banks. Upon presentation of a confirmed export order or...

  8. 77 FR 61738 - Circular Welded Carbon Steel Pipes and Tubes From Thailand: Final Results of Antidumping Duty...

    Science.gov (United States)

    2012-10-11

    ... International Trade Administration Circular Welded Carbon Steel Pipes and Tubes From Thailand: Final Results of..., Department of Commerce. SUMMARY: On April 6, 2012, the Department of Commerce (the Department) published the... pipes and tubes from Thailand.\\1\\ This review covers the respondents Pacific Pipe Public Company...

  9. 75 FR 67108 - Cut-To-Length Carbon Steel Plate From India, Indonesia, Italy, Japan, and Korea

    Science.gov (United States)

    2010-11-01

    ..., Italy, Japan, and Korea (70 FR 72607). The Commission is now conducting second reviews to determine..., subparts A, D, E, and F (19 CFR part 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1... orders on imports of CTL carbon steel plate from India, Indonesia, Italy, and Korea (65 FR 6587)...

  10. 76 FR 19788 - Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand

    Science.gov (United States)

    2011-04-08

    ... determined on January 4, 2011 that it would conduct expedited reviews (76 FR 5205). The Commission... COMMISSION Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand... fittings from Brazil, China, Japan, Taiwan, and Thailand would be likely to lead to continuation...

  11. 76 FR 8772 - Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan and Korea

    Science.gov (United States)

    2011-02-15

    ... the domestic interested party group response to its notice of institution (75 FR 67108, November 1... COMMISSION Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan and Korea AGENCY: United..., Indonesia, Italy, Japan, and Korea. SUMMARY: The Commission hereby gives notice that it will proceed...

  12. 77 FR 73674 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, The United Arab Emirates, and Vietnam

    Science.gov (United States)

    2012-12-11

    ..., 2012 (77 FR 37711). The hearing was held in Washington, DC, on October 17, 2012, and all persons who... countervailing duty determination with respect to circular welded carbon-quality steel pipe from Vietnam (77 FR 64471, October 22, 2012), the Commission terminated investigation No. 701-TA-485 (77 FR 65712,...

  13. 77 FR 37711 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam...

    Science.gov (United States)

    2012-06-22

    ... detailed scope language, see 77 FR 19635, April 2, 2012. For further information concerning the conduct of... COMMISSION Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam...-fair-value imports from India, Oman, the United Arab Emirates, and Vietnam of circular welded...

  14. Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2015-01-01

    Full Text Available While NaNO2 addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance, ca. 100 times more NaNO2 addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed whereby NO2- ion is added to oxidize. The NO2- ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2 addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation by NO2- ion; however, regardless of the alloys, nitrogen compounds (not nitrite were detected at the outermost surface but were not incorporated in the inner oxide.

  15. 75 FR 47263 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Final...

    Science.gov (United States)

    2010-08-05

    ....'' \\1\\ See Initiation of Five-Year (``Sunset'') Review, 75 FR 16437 (April 1, 2010) (Notice of..., 75 FR 16437 (2010). Section 351.218(d)(1)(i) of the Department's regulations provides domestic... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the...

  16. 78 FR 73827 - Suspension Agreement on Certain Cut-to-Length Carbon Steel Plate From the Russian Federation...

    Science.gov (United States)

    2013-12-09

    ... Certain Cut-to-Length Carbon Steel Plate from the Russian Federation, 68 FR 3859 (January 27, 2003... of the Antidumping Duty Suspension Agreement, 78 FR 61333 (October 3, 2013) and accompanying Decision... Russian Federation; Final Results of Antidumping Duty Administrative Review AGENCY: Enforcement...

  17. Effect of Thermomechanical Controlled Processing on Mechanical Properties of 490 MPa Grade Low Carbon Cold Heading Steel

    Institute of Scientific and Technical Information of China (English)

    LI Zhuang

    2009-01-01

    Thermomechanical controlled processing (TMCP) of low carbon cold heading steel in different austenite conditions were conducted by a laboratory hot rolling mill.Effect of various processing parameters on the mechanical properties of the steel was investigated.The results showed that the mechanical properties of the low carbon cold heading steel could be significantly improved by TMCP without heat treatment.The improvement of mechanical properties can be attributed mainly to the ferrite grain refinement due to low temperature rolling.In the experiments the better ultimate tensile strength and ductility are obtained by lowering finishing cooling temperature within the temperature range from 650 ℃ to 550 ℃ since the interlamellar space in pearlite colonies become smaller.Good mechanical properties can be obtained in a proper austenite condition and thermomechanical processing parameter.The ferrite morphology has a more pronounced effect on the mechanical behavior than refinement of the microstructure.It is possible to realize the replacement of medium-carbon by low-carbon for 490 Mpa grade cold heading steel with TMCP.

  18. 77 FR 32552 - Circular Welded Carbon-Quality Steel Pipe From the Socialist Republic of Vietnam: Preliminary...

    Science.gov (United States)

    2012-06-01

    ... imports from an NME country, section 773(c)(1) of the Act directs it to base normal value (NV), in most... merchandise (i.e., by CONNUM). We based all of our targeted dumping calculations on the U.S. net price, which... Determination of Sales at Less Than Fair Value: Certain Cold-Rolled Flat-Rolled Carbon-Quality Steel...

  19. Microstructural Evolution of a Low-Carbon Steel during Application of Quenching and Partitioning Heat Treatments after Partial Austenitization

    NARCIS (Netherlands)

    Santofimia, M.J.; Zhao, L.; Sietsma, J.

    2008-01-01

    The “quenching and partitioning” (Q&P) process has been studied in a low-carbon steel containing 1.1 wt pct aluminum by heat treatments consisting of partial austenitization at 900 °C and subsequent rapid cooling to a quenching temperature in the range between 125 °C and 175 °C, followed by an isoth

  20. 78 FR 55241 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-10

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) is conducting an administrative review of the countervailing duty (CVD) order on corrosion-resistant.... SUPPLEMENTARY INFORMATION: Scope of the Order The merchandise covered by this Order \\2\\ is certain...