Investigations of corrosion films formed on API-X52 pipeline steel in acid sour media

International Nuclear Information System (INIS)

Hernandez-Espejel, A.; Dominguez-Crespo, M.A.; Cabrera-Sierra, R.; Rodriguez-Meneses, C.; Arce-Estrada, E.M.

2010-01-01

Corrosion films formed by voltammetry using different switching potentials and by immersion on API-X52 pipeline steel in simulated acid sour media (NACE ID182) have been characterized using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Linear Polarization and Electrochemical Impedance Spectroscopy (EIS) techniques. XRD and EDS analysis showed that the films are mainly composed of sulphide compounds (mackinawite, troilite, marcasite and pyrite) as well as iron oxides, as steel damage increases. Across SEM micrographs the corrosion films formed by potentiodynamic and immersion tests are very similar, covering most of the steel. Polarization and EIS results corroborate poor behavior against corrosion.

Erosion Behaviour of API X100 Pipeline Steel at Various Impact Angles and Particle Speeds

Directory of Open Access Journals (Sweden)

Paul C. Okonkwo

2016-09-01

Full Text Available Erosion is the gradual removal of material due to solid particle impingement and results in a failure of pipeline materials. In this study, a series of erosion tests were carried out to investigate the influence of particle speed and impact angle on the erosion mechanism of API X100 pipeline steel. A dry erosion machine was used as the test equipment, while the particle speed ranged from 20 to 80 m/s and impact angles of 30° and 90° were used as test parameters. The eroded API X100 steel surface was characterized using scanning electron microscope (SEM and X-ray photoelectron spectroscopy (XPS. The weight loss and erosion rate were also investigated. The results showed that at a 90° impact angle, a ploughing mechanism was occurring on the tested specimens, while material removal through low-angle cutting was the dominant mechanism at lower impact angles. Embedment of alumina particles on the target steel surface, micro-cutting, and low-angle cutting were observed at low impact angles. Therefore, the scratches, cuttings, and severe ploughings observed on some failed oil and gas pipelines could be attributed to the erosion mechanism.

EBSD study of hydrogen-induced cracking in API-5 L-X46 pipeline steel

International Nuclear Information System (INIS)

Venegas, V.; Caleyo, F.; Gonzalez, J.L.; Baudin, T.; Hallen, J.M.; Penelle, R.

2005-01-01

The spatial distribution of plastic deformation and grain orientation surrounding hydrogen-induced cracks (HIC) is investigated in samples of API-5L-X46 pipeline steel using scanning electron microscopy and electron backscattering diffraction (EBSD). This work shows direct experimental evidence of the influence of microstructure, microtexture and mesotexture on HIC crack path

2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

International Nuclear Information System (INIS)

Sadeghi Meresht, E.; Shahrabi Farahani, T.; Neshati, J.

2012-01-01

Highlights: ► Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. ► The techniques include weight loss, potentiodynamic polarization, EIS and AFM. ► 2-Butyne-1,4-diol acts as a mixed-type inhibitor. ► The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na 2 CO 3 /1 M NaHCO 3 solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of −21.08 kJ mol −1 .

Microbial Corrosion of API 5L X-70 Carbon Steel by ATCC 7757 and Consortium of Sulfate-Reducing Bacteria

Directory of Open Access Journals (Sweden)

Arman Abdullah

2014-01-01

Full Text Available Various cases of accidents involving microbiology influenced corrosion (MIC were reported by the oil and gas industry. Sulfate reducing bacteria (SRB have always been linked to MIC mechanisms as one of the major causes of localized corrosion problems. In this study, SRB colonies were isolated from the soil in suspected areas near the natural gas transmission pipeline in Malaysia. The effects of ATCC 7757 and consortium of isolated SRB upon corrosion on API 5L X-70 carbon steel coupon were investigated using a weight loss method, an open circuit potential method (OCP, and a potentiodynamic polarization curves method in anaerobic conditions. Scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDS were then used to determine the corrosion morphology in verifying the SRB activity and corrosion products formation. Results from the study show that the corrosion rate (CR of weight loss method for the isolated SRB is recorded as 0.2017 mm/yr compared to 0.2530 mm/yr for ATCC 7757. The Tafel plot recorded the corrosion rate of 0.3290 mm/yr for Sg. Ular SRB and 0.2500 mm/yr for Desulfovibrio vulgaris. The results showed that the consortia of isolated SRB were of comparable effects and features with the single ATCC 7757 strain.

Carbonic anhydrase from Apis mellifera: purification and inhibition by pesticides.

Science.gov (United States)

Soydan, Ercan; Güler, Ahmet; Bıyık, Selim; Şentürk, Murat; Supuran, Claudiu T; Ekinci, Deniz

2017-12-01

Carbonic anhydrase (CA) enzymes have been shown to play an important role in ion transport and in pH regulation in several organisms. Despite this information and the wealth of knowledge regarding the significance of CA enzymes, few studies have been reported about bee CA enzymes and the hazardous effects of chemicals. Using Apis mellifera as a model, this study aimed to determine the risk of pesticides on Apis mellifera Carbonic anhydrase enzyme (Am CA). CA was initially purified from Apis mellifera spermatheca for the first time in the literature. The enzyme was purified with an overall purification of ∼35-fold with a molecular weight of ∼32 kDa. The enzyme was then exposed to pesticides, including tebuconazole, propoxur, carbaryl, carbofuran, simazine and atrazine. The six pesticides dose-dependently inhibited in vitro AmCA activity at low micromolar concentrations. IC 50 values for the pesticides were 0.0030, 0.0321, 0.0031, 0.0087, 0.0273 and 0.0165 μM, respectively. The AmCA inhibition mechanism of these compounds is unknown at this moment.

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

2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

Energy Technology Data Exchange (ETDEWEB)

Sadeghi Meresht, E. [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Shahrabi Farahani, T., E-mail: tshahrabi34@modares.ac.ir [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Neshati, J. [Research Institute of Petroleum Industry, RIPI, 1485733111, Tehran (Iran, Islamic Republic of)

2012-01-15

Highlights: Black-Right-Pointing-Pointer Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. Black-Right-Pointing-Pointer The techniques include weight loss, potentiodynamic polarization, EIS and AFM. Black-Right-Pointing-Pointer 2-Butyne-1,4-diol acts as a mixed-type inhibitor. Black-Right-Pointing-Pointer The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na{sub 2}CO{sub 3}/1 M NaHCO{sub 3} solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of -21.08 kJ mol{sup -1}.

Construction and assembly of pipelines using API 5L grade X80 tubes - considerations to be observed with high-strength steels; Construcao e montagem de dutos terrestres utilizando tubos API 5L Gr. X80

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Ailton C. de; Rabello, Jose Mauricio B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2005-07-01

The use of line pipes API 5L Grade X80, at the point of view of designer allows: reduction of wall thickness and pipe weight or increase of design pressure. In the pipeline construction point of view, the use of line pipes API 5L Grade X80 provide some advantages, however some difficulties must be expected in several stages of the construction and assembly. The implications in cost, productivity, inspection and integrity, with the application of these high resistance steels, complying with PETROBRAS Standard N - 464 Construcao, Montagem e Condicionamento de Dutos Terrestres (Rev. H - 2004 Dec) and the experience consolidated in pipelines construction abroad were presented. At the design stage, a comparison between pipelines designed using API 5L-X70 and API 5L-X80 was carried out approaching the aspects of variation of thickness, pressure design and design factor. An evaluation of the expected gains when choosing API 5L Grade X80 steels were done, regarding reduction of costs and pipe weight. Regarding API 5L-X80 pipe fabrication, the obtained results were reported, proving that this aspect was already overcome, showing the viability of its production in Brazil. Difficulties were detected regarding construction and assembly stage and showing the need of revision of PETROBRAS standard N-464. (author)

Connections: Superplasticity, Damascus Steels, Laminated Steels, and Carbon Dating

Science.gov (United States)

Wadsworth, Jeffrey

2016-12-01

In this paper, a description is given of the connections that evolved from the initial development of a family of superplastic plain carbon steels that came to be known as Ultra-High Carbon Steels (UHCS). It was observed that their very high carbon contents were similar, if not identical, to those of Damascus steels. There followed a series of attempts to rediscover how the famous patterns found on Damascus steels blades were formed. At the same time, in order to improve the toughness at room temperature of the newly-developed UHCS, laminated composites were made of alternating layers of UHCS and mild steel (and subsequently other steels and other metals). This led to a study of ancient laminated composites, the motives for their manufacture, and the plausibility of some of the claims relating to the number of layers in the final blades. One apparently ancient laminated composite, recovered in 1837 from the great pyramid of Giza which was constructed in about 2750 B.C., stimulated a carbon dating study of ancient steels. The modern interest in "Bladesmithing" has connections back to many of these ancient weapons.

Determination of Burst Pressure of API Steel Pipes using Stress Modified Critical Strain Model

International Nuclear Information System (INIS)

Alang, N A; Razak, N A; Sulaiman, A S

2012-01-01

This paper presents a technique which can be used to determine the burst pressure of defective steel pipes using non-linear finite element (FE) analysis. The technique uses stress modified critical strain (SMCS) failure criterion to study the effect of gouge defects on maximum working pressure of API X65 steel pipes. The procedures in determining the model parameters using 3-D, homogeneous isotropic elastic-plastic material model with large deformation finite element analyses from notched tensile bars were systematically discussed. The relationship between burst pressure and gouge depth was proposed. The burst pressure estimated then was compared to experimental data from the literature for validation showing overall good agreements.

Effect of Ethanol Chemistry on SCC of Carbon Steel

Science.gov (United States)

2011-02-22

Pipeline companies have a keen interest in assessing the feasibility of transporting fuel grade ethanol (FGE) and ethanol blends in existing pipelines. Previous field experience and laboratory research, funded by PRCI and API, has shown that steel ca...

Evaluation of the susceptibility to pitting corrosion of steel api 5L x42 exposed to solutions containing chloride ions and CO{sub 2} by electrochemical noise measurements; Evaluacion de la susceptibilidad a la corrosion por picado del acero api 5l x42 expuesto a un ambiente con cloruros y CO{sub 2} mediante la tecnica de ruido electroquimico

Energy Technology Data Exchange (ETDEWEB)

Pena-Ballesteros, D.; Rodriguez-Vanegas, N.; Anteliz, C.; Sarmiento Klapper, H.

2011-07-01

The concentration of chloride ions and the partial pressure of CO{sub 2} play an important role in the degradation of low-carbon steels used for the construction of pipelines in oil and gas industry. In order to evaluate the susceptibility of carbon steel API 5L X42 to pitting corrosion electrochemical noise and linear polarization resistance measurements were carried out in aqueous solutions containing chloride ions and CO{sub 2}. The concentration of chloride ions was varied between, 10000 and 18000 ppm, and the CO{sub 2} partial pressure between 10 psi and 18 psi. Experimental results pointed out that the formation of protective layer, consisting mainly of FeCO{sub 3}, depends on the partial pressure of CO{sub 2} in the system. Nevertheless, the stability of this layer was considerably affected by increasing the concentration of chloride ions causing that localized corrosion has taken place in some areas of the surface of API 5L X42, which were detected by electrochemical noise technique. (Author) 10 refs.

Validation of methods for WDXRF and OES-spark techniques in steel analysis. Determination of the uncertainty of measurements for API steel plant sample

International Nuclear Information System (INIS)

Silva, Carlos Eduardo da

2009-01-01

The increase of gas and petroleum demanding in the national and international markets, the specification and certification of the chemical analysis results of gas and oil pipe-line have became more and more challenging. A continuous development has been outlined to improve API grade alloy steels (American Petroleum Institute). The steel properties depend on the chemical composition control and process parameters during its manufacturing. In this work, a comparison of the measurement uncertainty between X-ray fluorescence (WD system) and Optical Emission (OES-spark) spectrometry, for API grade steel plant samples analysis, was outlined. Usually, this kind of analyze requires less than 40 seconds for full chemical characterization for adjustment in the process parameters production. The main influence source in the chemical analysis was evaluated for design of experiments. The constituents and trace elements such as Al, Si, P, S, Ti, V, Cr, Mn, Co, Ni, Cu, As, Nb, Mo and Sn were determined using the ASTM E-322, E-415, E-1009 and E-1085 standard methodologies. The 185A and 187A certified reference materials from CMI (Czech Metrology Institute) were used for evaluation of the methods. The uncertainty of the measurement, precision, accuracy, repeatability and reproducibility of the measurements were obtained applying statistic tests, recommended by ISO/IEC 17025. The uncertainty of measurement for each element is discussed for both techniques. (author)

On high temperature strength of carbon steels

International Nuclear Information System (INIS)

Ichinose, Hiroyuki; Tamura, Manabu; Kanero, Takahiro; Ihara, Yoshihito

1977-01-01

In the steels for high temperature use, the oxidation resistance is regarded as important, but carbon steels show enough oxidation resistance to be used continuously at the temperature up to 500 deg. C if the strength is left out of consideration, and up to 450 deg. C even when the strength is taken into account. Moreover, the production is easy, the workability and weldability are good, and the price is cheap in carbon steels as compared with alloy steels. In the boilers for large thermal power stations, 0.15-0.30% C steels are used for reheater tubes, main feed water tubes, steam headers, wall water tubes, economizer tubes, bypass pipings and others, and they account for 70% of all steel materials used for the boilers of 350 MW class and 30% in 1000 MW class. The JIS standard for the carbon steels for high temperature use and the related standards in foreign countries are shown. The high temperature strength of carbon steels changes according to the trace elements, melting and heat treatment as well as the main compositions of C, Si and Mn. Al and N affect the high temperature strength largely. The characteristics of carbon steels after the heating for hours, the factors controlling the microstructure and high temperature strength, and the measures to improve the high temperature strength of carbon steels are explained. (Kako, I.)

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.

The effect of hot strip mill processing parameters and alloy addition on low temperature toughness of API-X70 steel

Energy Technology Data Exchange (ETDEWEB)

Ro, Kwang Seop; Al-Shammary, Saad; Al-Butairi, Adel A. [QA and PTS, SAUDI IRON and STEEL COMAPNY, Al-Jubail, (Saudi Arabia); Al-Hajeri, Khaled F. [Saudi Basic Industries Corporation, Jubail, (Saudi Arabia)

2010-07-01

The design of high strength steel grade is based on stringent specifications in terms of chemistry, mechanical properties and surface requirements. This study investigated the effect of alloy addition on low temperature toughness of API X70 pipeline steel. Seven different chemical compositions have been selected for experimental testing. Ni, Cr and Cu were added in various quantities to the tested material without deteriorating the phase transformation to acicular ferrite. A tensile test, Charpy impact test, DWTT pressed notch test and microstructural observations using optical microscope and SEM were carried out. Statistical analyses were done to identify the relationship between chemical composition and DWTT shear area. The following equation showed excellent agreement with the experimental test data: Pct Shear aero of DWTT (-10 degrees C) = 954 - 0.3*SRT + 0.5*TBT - 0.4*FRT + 0.04*CT - 306*C - 60*(Mn+Ni+Cu) + 38*(Mo+Cr) - 791*(Ti+Nb+V) - 4*MA. The results showed that it is possible to design high strength API X 70 steel grades with good DWTT toughness by using the statistical equation that was developed.

Distinguishing feral and managed honeybees (Apis mellifera) using stable carbon isotopes

OpenAIRE

Anderson , Lucy; Dynes , Travis; Berry , Jennifer; Delaplane , Keith; McCormick , Lydia; Brosi , Berry

2014-01-01

International audience; The ability to distinguish feral and managed honeybees (Apis mellifera) has applications in studies of population genetics, parasite transmission, pollination, interspecific interactions, and bee breeding. We evaluated a diagnostic test based on theoretical differences in stable carbon isotope ratios generated by supplemental feeding. We evaluated (1) if carbon isotope ratios can distinguish feral and managed honeybees and (2) the temporal persistence of the signal aft...

The influence of surface roughness on the hydrogen permeation of type API 5L-X52 steel; Influencia del acabado superficial en la permeacion de hidrogeno del acero API 5L-X52 steel

Energy Technology Data Exchange (ETDEWEB)

Requiz, R; Vera, N; Camero, S

2004-07-01

The influence of surface reoughness on the corrosion and hydrogen permeation behaviour was evaluated on a type API 5L-52 steel in dearated 0.1M NaSO{sub 4} at pH=2. Potentiodynamic polarization curves were emplyed to determine the electrochemical behaviour of the steel, while the Devanathan-Stachurski technique was used to estimate the hydrogen permeation rate. Additionally, the surface roughness profiles were obtained in order to correlate the changes in the hydrogen perkeation rate with different metal surface finishings. The obtained results clearly demonstrate that when the roughness parameters have larger values, the cathodic current of hydrogen evolution increases while the hydrogen entry rate decreases. This effect can be attributed to the microstructural defects induced at the steel surface, such as dislocations, which increase the catalytic activity of the atomic hydrogen favouring its recombination. Also, these defects could allow the atomic hydrogen to remain adsorbed on the steel surface. Both effects could hinder the hydrogen diffusion into the metal since the possibility for this atom of becoming absorbed has been reduced. (Author) 16 refs.

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

Directory of Open Access Journals (Sweden)

Wenning Shen

Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

Understanding API-polymer proximities in amorphous stabilized composite drug products using fluorine-carbon 2D HETCOR solid-state NMR.

Science.gov (United States)

Abraham, Anuji; Crull, George

2014-10-06

A simple and robust method for obtaining fluorine-carbon proximities was established using a (19)F-(13)C heteronuclear correlation (HETCOR) two-dimensional (2D) solid-state nuclear magnetic resonance (ssNMR) experiment under magic-angle spinning (MAS). The method was applied to study a crystalline active pharmaceutical ingredient (API), avagacestat, containing two types of fluorine atoms and its API-polymer composite drug product. These results provide insight into the molecular structure, aid with assigning the carbon resonances, and probe API-polymer proximities in amorphous spray dried dispersions (SDD). This method has an advantage over the commonly used (1)H-(13)C HETCOR because of the large chemical shift dispersion in the fluorine dimension. In the present study, fluorine-carbon distances up to 8 Å were probed, giving insight into the API structure, crystal packing, and assignments. Most importantly, the study demonstrates a method for probing an intimate molecular level contact between an amorphous API and a polymer in an SDD, giving insights into molecular association and understanding of the role of the polymer in API stability (such as recrystallization, degradation, etc.) in such novel composite drug products.

Mechanical properties and fatigue strength of high manganese non-magnetic steel/carbon steel welded joints

International Nuclear Information System (INIS)

Nakaji, Eiji; Ikeda, Soichi; Kim, You-Chul; Nakatsuji, Yoshihiro; Horikawa, Kosuke.

1997-01-01

The dissimilar materials welded joints of high manganese non-magnetic steel/carbon steel (hereafter referred to as DMW joints), in which weld defects such as hot crack or blowhole are not found, were the good quality. Tensile strength of DMW joints was 10% higher than that of the base metal of carbon steel. In the bend tests, the DMW joints showed the good ductility without crack. Charpy absorbed energy at 0(degC) of the DMW joints was over 120(J) in the bond where it seems to be the lowest. Large hardening or softening was not detected in the heat affected zone. Fatigue strength of the DMW joints is almost the same with that of the welded joints of carbon steel/carbon steel. As the fatigue strength of the DMW joints exceeds the fatigue design standard curve of JSSC for carbon steel welded joints, the DMW joints can be treated the same as the welded joints of carbon steel/carbon steel of which strength is lower than that of high manganese non-magnetic steel, from the viewpoint of the fatigue design. (author)

Corrosion of API 5L B and X52 in crude oil/water/gas mixtures

Energy Technology Data Exchange (ETDEWEB)

Perdomo, J J; Gonzalez, J J; Viloria, A; De Veer, H; De Abreu, Y

2000-02-01

Laboratory and field tests were conducted to evaluate the corrosion behavior of API 5L grade B and X52 steels using Furrial's crude oil in the presence of water and gas containing carbon dioxide (CO{sub 2}) and hydrogen sulfide (H{sub 2}S). The results suggest that the corrosiveness of this crude oil/water/gas mixture is not detrimental to either steel. However, pitting corrosion was observed. The low general corrosion rates measured were attributed to the natural inhibiting properties of the crude oil.

Corrosion of API 5L B and X52 in crude oil/water/gas mixtures

Energy Technology Data Exchange (ETDEWEB)

Perdomo, J.J.; Gonzalez, J.J.; Viloria, A.; De Veer, H.; De Abreu, Y.

2000-02-01

Laboratory and field tests were conducted to evaluate the corrosion behavior of API 5L grade B and X52 steels using Furrial's crude oil in the presence of water and gas containing carbon dioxide (CO{sub 2}) and hydrogen sulfide (H{sub 2}S). The results suggest that the corrosiveness of this crude oil/water/gas mixture is not detrimental to either steel. However, pitting corrosion was observed. The low general corrosion rates measured were attributed to the natural inhibiting properties of the crude oil.

Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

Science.gov (United States)

Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

2015-07-01

The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

Cubic martensite in high carbon steel

Science.gov (United States)

Chen, Yulin; Xiao, Wenlong; Jiao, Kun; Ping, Dehai; Xu, Huibin; Zhao, Xinqing; Wang, Yunzhi

2018-05-01

A distinguished structural characteristic of martensite in Fe-C steels is its tetragonality originating from carbon atoms occupying only one set of the three available octahedral interstitial sites in the body-centered-cubic (bcc) Fe lattice. Such a body-centered-tetragonal (bct) structure is believed to be thermodynamically stable because of elastic interactions between the interstitial carbon atoms. For such phase stability, however, there has been a lack of direct experimental evidence despite extensive studies of phase transformations in steels over one century. In this Rapid Communication, we report that the martensite formed in a high carbon Fe-8Ni-1.26C (wt%) steel at room temperature induced by applied stress/strain has actually a bcc rather than a bct crystal structure. This finding not only challenges the existing theories on the stability of bcc vs bct martensite in high carbon steels, but also provides insights into the mechanism for martensitic transformation in ferrous alloys.

Interphase and intergranular stress generation in carbon steels

International Nuclear Information System (INIS)

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

2004-01-01

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

Passivation condition of carbon steel in bentonite/sand mixture

International Nuclear Information System (INIS)

Taniguchi, Naoki; Kawakami, Susumu

2002-03-01

It is essential to understand the corrosion type of carbon steel under the repository conditions for the lifetime assessment of carbon steel overpack used for geological isolation of high-level radioactive waste. According to the previous study, carbon steel is hard to passivate in buffer material assuming a chemical condition range of groundwater in Japan. However, concrete support will be constructed around the overpack in the case of repository in the soft rock system and groundwater having a higher pH may infiltrate to buffer material. There is a possibility that the corrosion type of carbon steel will be influenced by the rise of the pH in groundwater. In this study, anodic polarization experiments were performed to understand the passivation condition of carbon steel in buffer material saturated with water contacted with concrete. An ordinary concrete an a low-alkalinity concrete were used in the experiment. The results of the experiments showed that the carbon steel can passivate under the condition that water having pH > 13 infiltrate to the buffer material assuming present property of buffer material. If the low-alkalinity concrete is selected as the support material, passivation can not occur on carbon steel overpack. The effect of the factors of buffer material such as dry density and mixing ratio of sand on the passivation of carbon steel was also studied. The results of the study showed that the present property of buffer material is enough to prevent passivation of carbon steel. (author)

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

Science.gov (United States)

Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

Effect of Pipe Flattening in API X65 Linepipe Steels Having Bainite vs. Ferrite/Pearlite Microstructures

Directory of Open Access Journals (Sweden)

Singon Kang

2018-05-01

Full Text Available The influence of microstructure on pipe flattening response was assessed using two different commercially produced U-ing, O-ing, and expansion (UOE pipes from API X65 steels having either a bainitic microstructure (steel B or a ferrite/pearlite microstructure (steel FP. A four-point bending apparatus and distinctive procedure were used to minimize strain localization during flattening. The flattened specimens were sectioned at different positions through the thickness, and tensile tested in both the longitudinal (LD and transverse directions (TD to assess the through-thickness variation in properties. Yield strength (YS distributions in the LD show V-shaped profiles through thickness in both steels, whereas the YS in the TD nearest the outside diameter (OD surface is reduced. These variations in YS are due to the Bauschinger effect associated with the compressive flattening pre-strain. The uniform elongation (UE of steel FP is almost independent of specimen position through the thickness, but for steel B there is a substantial reduction of the UE at both the inside and outside diameter positions and this reduction is greater in the LD. This work confirms that flattened pipe mechanical properties exhibit an important dependence on their microstructure type and it is postulated that the flattening procedure also influences the mechanical properties.

Corrosion of carbon steel in contact with bentonite

International Nuclear Information System (INIS)

Dobrev, D.; Vokal, A.; Bruha, P.

2010-01-01

Document available in extended abstract form only. Carbon steel canisters were chosen in a number of disposal concepts as reference material for disposal canisters. The corrosion rates of carbon steels in water solution both in aerobic and anaerobic conditions are well known, but only scarce data are available for corrosion behaviour of carbon steels in contact with bentonite. A special apparatus, which enables to measure corrosion rate of carbon steels under conditions simulating conditions in a repository, namely in contact with bentonite under high pressure and elevated temperatures was therefore prepared to study: - Corrosion rate of carbon steels in direct contact with bentonite in comparison with corrosion rate of carbon steels in synthetic bentonite pore water. - Influence of corrosion products on bentonite. The apparatus is composed of corrosion chamber containing a carbon steel disc in direct contact with compacted bentonite. Synthetic granitic water is above compacted bentonite under high pressure (50 - 100 bar) to simulate hydrostatic pressure in a repository. The experiments can be carried out under various temperatures. Bentonites used for experiments were Na-type of bentonite Volclay KWK 80 - 20 and Ca-Mg Czech bentonite from deposit Rokle. Before adding water into corrosion system the corrosion chamber was purged by nitrogen gas. The saturation of bentonite and corrosion rate were monitored by measuring consumption of water, pressure increase caused by swelling pressure of bentonite and by generation of hydrogen. Corrosion rate was also determined after corrosion experiments from weight loss of samples. The results of experiments show that the corrosion behaviour of carbon steels in contact with bentonite is very different from corrosion of carbon steels in water simulating bentonite pore water solution. The corrosion rates of carbon steel in contact with bentonite reached after 30 days of corrosion the values approaching 40 mm/yr contrary to values

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.

Characterization of Mechanical Properties and Residual Stress in API 5L X80 Steel Welded Joints

Science.gov (United States)

de Sousa Lins, Amilton; de Souza, Luís Felipe Guimarães; Fonseca, Maria Cindra

2018-01-01

The use of high-strength and low-alloy steels, high design factors and increasingly stringent safety requirements have increased the operating pressure levels and, consequently, the need for further studies to avoid and prevent premature pipe failure. To evaluate the possibility of improving productivity in manual arc welding of this type of steel, this work characterizes the mechanical properties and residual stresses in API 5L X80 steel welded joints using the SMAW and FCAW processes. The residual stresses were analyzed using x-ray diffraction with the sin2 ψ method at the top and root of the welded joints in the longitudinal and transverse directions of the weld bead. The mechanical properties of the welded joints by both processes were characterized in terms of tensile strength, impact toughness and Vickers microhardness in the welded and shot peening conditions. A predominantly compressive residual stress was found, and shot peening increased the tensile strength and impact toughness in both welded joints.

Corrosion of carbon steel welds

International Nuclear Information System (INIS)

Daniel, B.

1988-09-01

This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

Inhibition of Corrosion of Carbon Steel in 3.5% NaCl Solution by Myrmecodia Pendans Extract

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Atria Pradityana

2016-01-01

Full Text Available Inhibitor is a substance that is added to the corrosive media to inhibit corrosion rate. Organic inhibitors are preferred to inorganic ones since they are environmentally friendly. One of the organic compounds which is rarely reported as a corrosion inhibitor is Myrmecodia Pendans. The organic compounds can be adsorbed on the metal surface and block the active surface to reduce the rate of corrosion. In this study, the used pipe was carbon steel API 5L Grade B with 3.5% NaCl solution as the corrosion medium. The objective of this research was to analyze the inhibition mechanism Myrmecodia Pendans towards carbon steel in a corrosion medium. Concentration variations of extract Myrmecodia Pendans were 0–500 ppm. Fourier Transform Infrared (FTIR was used for chemical characterization of Myrmecodia Pendans. Polarization and Electrochemical Impedance Spectroscopy (EIS were used to measure the corrosion rate and behaviour. From the electrochemical measurements, it was found that the addition of 400 mg/L inhibitor gave the highest inhibition efficiency. Myrmecodia Pendans acted as a corrosion inhibitor by forming a thin layer on the metal surface.

Experimental and numerical simulation of carbon manganese steel ...

African Journals Online (AJOL)

Experimental and numerical simulation of carbon manganese steel for cyclic plastic behaviour. J Shit, S Dhar, S Acharyya. Abstract. The paper deals with finite element modeling of saturated low cycle fatigue and the cyclic hardening phenomena of the materials Sa333 grade 6 carbon steel and SS316 stainless steel.

The influence of surface roughness on the hydrogen permeation of type API 5L-X52 steel

International Nuclear Information System (INIS)

Requiz, R.; Vera, N.; Camero, S.

2004-01-01

The influence of surface roughness on the corrosion and hydrogen permeation behaviour was evaluated on a type API 5L-52 steel in dearated 0.1M NaSO 4 at pH=2. Potentiodynamic polarization curves were employed to determine the electrochemical behaviour of the steel, while the Devanathan-Stachurski technique was used to estimate the hydrogen permeation rate. Additionally, the surface roughness profiles were obtained in order to correlate the changes in the hydrogen perkeation rate with different metal surface finishings. The obtained results clearly demonstrate that when the roughness parameters have larger values, the cathodic current of hydrogen evolution increases while the hydrogen entry rate decreases. This effect can be attributed to the microstructural defects induced at the steel surface, such as dislocations, which increase the catalytic activity of the atomic hydrogen favouring its recombination. Also, these defects could allow the atomic hydrogen to remain adsorbed on the steel surface. Both effects could hinder the hydrogen diffusion into the metal since the possibility for this atom of becoming absorbed has been reduced. (Author) 16 refs

Corrosion of carbon steel in neutral water

International Nuclear Information System (INIS)

Kawai, Noboru; Iwahori, Toru; Kurosawa, Tatsuo

1983-01-01

The initial corrosion behavior of materials used in the construction of heat exchanger and piping system of BWR nuclear power plants and thermal power plants have been examined in neutral water at 30, 50, 100, 160, 200, and 285 deg C with two concentrations of dissolved oxygen in the water. In air-saturated water, the corrosion rate of carbon steel was so higher than those in deaerated conditions and the maximum corrosion rate was observed at 200 deg C. The corrosion rate in deaerated water gradually increased with increasing the water temperature. Low alloy steel (2.25 Cr, 1Mo) exhibited good corrosion resistance compared with the corrosion of carbon steel under similar testing conditions. Oxide films grown on carbon steel in deaerated water at 50, 100, 160, 200, and 285 deg C for 48 and 240 hrs were attacked by dissolved oxygen in room temperature water respectively. However the oxide films formed higher than about 160 deg C showed more protective. The electrochemical behavior of carbon steel with oxide films was also similar to the effect of temperature on the stability of oxide films. (author)

Comparative Study of API 5L X60 and ASTM 572 Gr50 Steel Exposed to Crude Oil and Seawater

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Marcy Viviana Chiquillo Márquez

2018-04-01

Full Text Available In the petroleum industry, the biphasic conditions in storage and separation tanks allow that the material to remain exposed to two different environments, causing its deterioration. In this article, an evaluation is made of the corrosive behavior and Vickers microhardness (HV of two high strength low alloy (HSLA steels and how their surfaces are characterized. The ASTM 572 Gr50 steel showed a lower corrosion rate in all systems after being immersed for 720 and 1440 hours. Characterizing the surface by means of Scanning Electron Microscopy (SEM showed uniform and localized corrosion for the both steels, and revealed that the ASTM 572 Gr50 steel shows pitting corrosion in crude oil systems. The electrochemical results revealed that the corrosion potential of API X60 steel was more negative; however the ASTM 572 Gr50 steel had a higher current density and a lower polarization resistance when immersed in an oil/seawater mixture. It also observed that, after being immersed in the corrosive fluids, the microstructures of the steels were not modified and variations in their microhardness (HV were minute.

Super-Hydrophobic Green Corrosion Inhibitor On Carbon Steel

Science.gov (United States)

Hassan, H.; Ismail, A.; Ahmad, S.; Soon, C. F.

2017-06-01

There are many examples of organic coatings used for corrosion protection. In particular, hydrophobic and super-hydrophobic coatings are shown to give good protection because of their enhanced ability to slow down transport of water and ions through the coating. The purpose of this research is to develop water repellent coating to avoid direct contact between metal and environment corrosive and mitigate corrosion attack at pipeline system. This water repellent characteristic on super-hydrophobic coating was coated by electrodeposition method. Wettability of carbon steel with super-hydrophobic coating (cerium chloride and myristic acid) and oxidized surface was investigated through contact angle and inhibitor performance test. The inhibitor performance was studied in 25% tannin acid corrosion test at 30°C and 3.5% sodium chloride (NaCl). The water contact angle test was determined by placing a 4-μL water droplet of distilled water. It shows that the wettability of contact angle super-hydrophobic with an angle of 151.60° at zero minute can be classified as super-hydrophobic characteristic. By added tannin acid as inhibitor the corrosion protection on carbon steel becomes more consistent. This reveals that the ability of the coating to withstand with the corrosion attack in the seawater at different period of immersions. The results elucidate that the weight loss increased as the time of exposure increased. However, the corrosion rates for uncoated carbon steel is high compared to coated carbon steel. As a conclusion, from both samples it can be seen that the coated carbon steel has less corrosion rated compared to uncoated carbon steel and addition of inhibitor to the seawater provides more protection to resist corrosion attack on carbon steel.

Corrosion behavior of carbon steel in wet Na-bentonite medium

International Nuclear Information System (INIS)

Yeon, Jae-Won; Ha, Young-Kyoung; Choi, In-Kyu; Chun, Kwan-Sik

1996-01-01

Corrosion behaviors of carbon steel in wet Na-bentonite medium were studied. Corrosion rate of carbon steel in wet bentonite was measured to be 20 μm/yr at 25 deg C using the AC impedance technique. This value is agreed with that obtained by weight loss at 40 deg C for 1 year. The effect of bicarbonate ion on the corrosion of carbon steel in wet bentonite was also evaluated. The carbon steels in wet bentonite having 0.001, 0.01, and 0.1 M concentration of bicarbonate ion gave corrosion rates of 20, 8, and 0.2 μm/yr, respectively. Corrosion potentials of specimens were also measured and compared with the AC impedance results. Both results indicated that bicarbonate ion could effectively reduce the corrosion rate of carbon steels in bentonite due to the formation of protective layer on the carbon steel. (author)

Corrosion resistance of ERW (Electric Resistance Welded) seam welds as compared to metal base in API 5L steel pipes

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Velasquez, Jorge L.; Godinez Salcedo, Jesus G.; Lopez Fajardo, Pedro [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE). Dept. de Ingenieria Metalurgica

2009-07-01

The corrosion resistance of ERW seam welds and the base metal in API 5L X70 steel pipes was evaluated by Tafel tests. The procedure was according to ASTM G3 standard. The study was completed with metallographic and chemical characterization of the tested zones, that is, the welded zone and the base metal away of the weld. All tests were made on the internal surface of the pipe in order to assess the internal corrosion of an in-service pipeline made of the API 5L X70 steel. The test solution was acid brine prepared according to NACE Publications 1D182 and 1D196. The results showed that the ERW seam weld corrodes as much as three times faster than the base material. This behavior is attributed to a more heterogeneous microstructure with higher internal energy in the ERW seam weld zone, as compared to the base metal, which is basically a ferrite pearlite microstructure in a normalized condition. This result also indicates that pipeline segments made of ERW steel pipe where the seam weld is located near or at the bottom of the pipe are prone to a highly localized attack that may form channels of metal loss if there is water accumulation at the bottom of the pipeline. (author)

Hardness and microstructural characterization of API 5L X70 steel pipes welded by HF/ERW process; Caracterizacao microestrutural e de dureza em tubos de aco API 5L X70 soldados pelo processo HF/ERW

Energy Technology Data Exchange (ETDEWEB)

Calcada, Mauricio Vieira; Voorwald, Herman Jacobus Cornelis; Nascimento, Marcelino Pereira do [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia

2010-07-01

The materials that stand in the manufacture of steel pipes are called API, that should have, high mechanical resistance, high corrosion resistance, high fatigue resistance, good weldability, and other properties. Thus, the purpose of this project was to evaluate the microstructure and hardness of welded joints by the HF/ERW process of API 5L X70 steel pipes. The microstructural analysis was performed using a surface finish with grit sizes from 220 to 25 {mu}m e polishing with diamond paste from 9 {mu}m to 0.05 {mu}m; the revelation was made with 3% Nital attack. The Vickers hardness was performed across the welded joint by 33 points to indentation. The results were: 80.5 {+-} 3.4% of ferrite and 19.5 {+-} 3.4% of perlite for microanalysis. As for hardness, the values were: 215.69 HV10 for weld line, 218.65 HV10 for ZTA and 218.95 HV10 for base metal. (author)

Effect of black clay soil moisture on the electrochemical behavior of API X70 pipeline steel

Science.gov (United States)

Hendi, R.; Saifi, H.; Belmokre, K.; Ouadah, M.; Smili, B.; Talhi, B.

2018-03-01

The effect of moisture content variation (20–100 wt.%) on the electrochemical behavior of API X70 pipeline steel buried in the soil of Skikda (East of Algeria) was studied using electrochemical techniques, scanning electron microscopy (SEM), X ray diffraction analysis (XRD) and weight loss measurement. The electrochemical measurements showed that the corrosion current Icorr is directly proportional to the moisture content up to 50 wt.%, beyond this content, this value becomes almost constant. The result were confirmed by electrochemical impedance spectroscopy; the capacitance of the double layer formed on the surface is the highest at 50 wt.%. A single time constant was detected by plotting the Bode diagrams. The steel surface degradation has been appreciated using the scanning electron microscopy observations. A few pitting corrosion at 20 wt.% moisture, followed by more degradation at 50 wt.% have been revealed. However, when the moisture amount exceeded 50 wt.%, the surface became entirely covered by a corrosion product. XRD analysis revealed the dominance of FeOOH and Fe3O4 phases on steel surface for a moisture content of 50 wt.%.

Electrochemical Corrosion Behavior of Carbon Steel and Hot Dip Galvanized Steel in Simulated Concrete Solution with Different pH Values

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Wanchen XIE

2017-08-01

Full Text Available Hot dip galvanizing technology is now widely used as a method of protection for steel rebars. The corrosion behaviors of Q235 carbon steel and hot galvanized steel in a Ca(OH2 solution with a pH from 10 to 13 was investigated by electrode potential and polarization curves testing. The results indicated that carbon steel and hot galvanized steel were all passivated in a strong alkaline solution. The electrode potential of hot dip galvanized steel was lower than that of carbon steel; thus, hot dip galvanized steel can provide very good anodic protection for carbon steel. However, when the pH value reached 12.5, a polarity reversal occurred under the condition of a certain potential. Hot dip galvanized coating became a cathode, and the corrosion of carbon steel accelerated. The electrochemical behaviors and passivation abilities of hot dip galvanized steel and carbon steel were affected by pH. The higher the pH value was, the more easily they were passivated.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16675

Effect of Different Thermomechanical Processes on the Microstructure, Texture, and Mechanical Properties of API 5L X70 Steel

Science.gov (United States)

Masoumi, Mohammad; Echeverri, Edwan Anderson Ariza; Silva, Cleiton Carvalho; Béreš, Miloslav; de Abreu, Hamilton Ferreira Gomes

2018-03-01

A commercial API 5L X70 steel plate was subjected to different thermomechanical processes to propose a novel thermomechanical rolling path to achieve improved mechanical properties. Scanning electron microscopy, electron backscatter diffraction, and x-ray texture analysis were employed for microstructural characterization. The results showed that strain-free recrystallized {001} ferrite grains that developed at higher rolling temperature could not meet the American Petroleum Institute (API) requirements. Also, refined and work-hardened grains that have formed in the intercritical region with high stored energy do not provide suitable tensile properties. However, fine martensite-austenite constituents dispersed in ferrite matrix with grains having predominantly {111} and {110} orientations parallel to the normal direction that developed under isothermal rolling at 850 °C provided an outstanding combination of tensile strength and ductility.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Trial manufacturing of titanium-carbon steel composite overpack

International Nuclear Information System (INIS)

Honma, Nobuyuki; Chiba, Takahiko; Tanai, Kenji

1999-11-01

This paper reports the results of design analysis and trial manufacturing of full-scale titanium-carbon steel composite overpacks. The overpack is one of the key components of the engineered barrier system, hence, it is necessary to confirm the applicability of current technique in their manufacture. The required thickness was calculated according to mechanical resistance analysis, based on models used in current nuclear facilities. The Adequacy of the calculated dimensions was confirmed by finite-element methods. To investigate the necessity of a radiation shielding function of the overpack, the irradiation from vitrified waste has been calculated. As a result, it was shown that shielding on handling and transport equipment is a more reasonable and practical approach than to increase thickness of overpack to attain a self-shielding capability. After the above investigation, trial manufacturing of full-scale model of titanium-carbon steel composite overpack has been carried out. For corrosion-resistant material, ASTM Grade-2 titanium was selected. The titanium layer was bonded individually to a cylindrical shell and fiat cover plates (top and bottom) made of carbon steel. For the cylindrical shell portion, a cylindrically formed titanium layer was fitted to the inner carbon steel vessel by shrinkage. For the flat cover plates (top and bottom), titanium plate material was coated by explosive bonding. Electron beam welding and gas metal arc welding were combined to weld of the cover plates to the body. No significant failure was evident from inspections of the fabrication process, and the applicability of current technology for manufacturing titanium-carbon steel composite overpack was confirmed. Future research and development items regarding titanium-carbon steel composite overpacks are also discussed. (author)

Study on corrosion of carbon steel in DEA aqueous solutions

Science.gov (United States)

Yang, Jun Han; Xie, Jia Lin; Zhang, Li

2018-02-01

Corrosion of carbon steel in the CO2 capture process using diethanolamine (DEA) aqueous solutions was investigated. The effects of the mass concentrations of DEA, solution temperature and CO2 loading on the corrosion rate of carbon steel were demonstrated. The experimental results provided comprehensive information on the appropriate concentration range of DEA aqueous solutions under which low corrosion of carbon steel can be achieved.

ICP-AES determination of trace elements in carbon steel

International Nuclear Information System (INIS)

Sengupta, Arijit; Rajeswari, B.; Kadam, R.M.; Babu, Y.; Godbole, S.V.

2010-01-01

Full text: Carbon steel, a combination of the elements iron and carbon, can be classified into four types as mild, medium, high and very high depending on the carbon content which varies from 0.05% to 2.1%. Carbon steel of different types finds application in medical devices, razor blades, cutlery and spring. In the nuclear industry, it is used in feeder pipes in the reactor. A strict quality control measure is required to monitor the trace elements, which have deleterious effects on the mechanical properties of the carbon steel. Thus, it becomes imperative to check the purity of carbon steel as a quality control measure before it is used in feeder pipes in the reactor. Several methods have been reported in literature for trace elemental determination in high purity iron. Some of these include neutron activation analysis, atomic absorption spectrometry and atomic emission spectrometry. Inductively coupled plasma atomic emission spectrometry (ICP-AES) is widely recognized as a sensitive technique for the determination of trace elements in various matrices, its major advantages being good accuracy and precision, high sensitivity, multi-element capability, large linear dynamic range and relative freedom from matrix effects. The present study mainly deals with the direct determination of trace elements in carbon steel using ICP-AES. An axially viewing ICP spectrometer having a polychromator with 35 fixed analytical channels and limited sequential facility to select any analytical line within 2.2 nm of a polychromator line was used in these studies. Iron, which forms one of the main constituents of carbon steel, has a multi electronic configuration with line rich emission spectrum and, therefore, tends to interfere in the determination of trace impurities in carbon steel matrix. Spectral interference in ICP-AES can be seriously detrimental to the accuracy and reliability of trace element determinations, particularly when they are performed in the presence of high

Study on Spheroidization and Related Heat Treatments of Medium Carbon Alloy Steels

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Harisha S. R.

2018-01-01

Full Text Available The importance of medium carbon steels as engineering materials is reflected by the fact that out of the vast majority of engineering grade ferrous alloys available and used in the market today, a large proportion of them are from the family of medium carbon steels. Typically medium carbon steels have a carbon range of 0.25 to 0.65% by weight, and a manganese content ranging from 0.060 to 1.65% by weight. Medium carbon steels are more resistive to cutting, welding and forming as compared to low carbon steels. From the last two decades a number of research scholars reported the use of verity of heat treatments to tailor the properties of medium carbon steels. Spheroidizing is the novel industrial heat treatment employed to improve formability and machinability of medium/high carbon low alloy steels. This exclusive study covers procedure, the effects and possible outcomes of various heat treatments on medium carbon steels. In the present work, other related heat treatments like annealing and special treatments for property alterations which serve as pretreatments for spheroidizing are also reviewed. Medium carbon steels with property alterations by various heat treatment processes are finding increased responsiveness in transportation, aerospace, space, underwater along with other variegated fields. Improved tribological and mechanical properties consisting of impact resistance, stiffness, abrasion and strength are the main reasons for the increased attention of these steels in various industries. In the present scenario for the consolidation of important aspects of various heat treatments and effects on mechanical properties of medium carbons steel, a review of different research papers has been attempted. This review may be used as a guide to provide practical data for heat treatment industry, especially as a tool to enhance workability and tool life.

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.

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.

Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65

International Nuclear Information System (INIS)

Diaz S, A.; Gonzalez F, E.; Arganis J, C.; Luna C, P.; Carapia M, L.

2004-01-01

In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

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

International Nuclear Information System (INIS)

Itty, Pierre-Adrien; Serdar, Marijana; Meral, Cagla; Parkinson, Dula; MacDowell, Alastair A.; Bjegović, Dubravka; Monteiro, Paulo J.M.

2014-01-01

Highlights: • The morphology of the corrosion of steel in cement paste was studied in situ. • During galvanostatic corrosion, carbon steel reinforcement corroded homogeneously. • On ferritic stainless steel, deep corrosion pits formed and caused wider cracks. • The measured rate of steel loss correlated well with Faraday’s law of electrolysis. - Abstract: 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

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

Study of sulphate-reducing bacteria corrosion in the weld joint for API X-70 steel

Energy Technology Data Exchange (ETDEWEB)

Flores, J. E.; Patino-Carachure, C.; Alfonso, I.; Rodriguez, J. A.; Rosas, G.

2012-11-01

The corrosion behavior originated by sulfate-reducing bacteria (SRB) was studied in two regions of welded API X-70 steel pipeline. The studies were focused on base material (BM) and heat affected zone (HAZ), from the internal region of the pipe. SRB were extracted from oil and grown in a Postgate medium. Corrosion was evaluated at 60 degree centigrade for times between 5 and 64 days. Potentiodynamic polarization curves, obtained by electrochemical techniques, indicated surface activation at short times. Structural and morphological characterizations were carried out by scanning electron microscopy (SEM) and optical microscopy (OM). H{sub 2}S concentration and pH were also measured. Results showed an important increase in the corrosion damage up to 20 days, influenced by the SRB activity, which lead to a maximum of H{sub 2}S (pH minimum). It was found a localized corrosion attack in the HAZ in a higher quantity compared to BM; and the formation of a thin film on the steel surface, originated by corrosion products and bacterial activity. (Author) 15 refs.

Medium carbon vanadium micro alloyed steels for drop forging

International Nuclear Information System (INIS)

Jeszensky, Gabor; Plaut, Ronald Lesley

1992-01-01

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)

Mixed structures in continuously cooled low-carbon automotive steels

International Nuclear Information System (INIS)

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

1993-01-01

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

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)

Effect of Microstructure on HIC Susceptibility of API X70MS Linepipe Steel

Energy Technology Data Exchange (ETDEWEB)

Sung, Joon-Ho; Sim, Ho-Seop; Park, Byung-Gyu [Dongkuk Steel R and D Center, Pohang (Korea, Republic of); Cho, Kyung-Mox [Pusan National University, Busan (Korea, Republic of)

2017-06-15

The resistance of hydrogen induced cracking (HIC) was investigated with different microstructures of API X70MS steel. Ferrite/acicular ferrite (F/AF), deformed ferrite/acicular ferrite, ferrite/bainite (F/B) and single acicular ferrite (AF) were obtained by thermo-mechanical controlled process (TMCP) with changing rolling and cooling conditions. HIC resistance was found to be affected by the type as well as morphology of the microstructure, and thus the behavior of crack initiation and propagation could be analyzed. It was found that single AF and deformed F/AF with uniformly distributed dislocation reduced HIC initiation. Banded microstructure with a hardness value below 250 HV, such as AF, showed good HIC propagation resistance due to high toughness. AF generally exhibited excellent crack initiation and propagation resistance, namely the best HIC susceptibility performance. AF might redeem the HIC resistance for the banded microstructure also.

Validation of methods for WDXRF and OES-spark techniques in steel analysis. Determination of the uncertainty of measurements for API steel plant sample; Validacao de metodos para as tecnicas de WDXRF e OES-spark na analise de acos. Calculo de incerteza de medicao para amostras de processo, aco classe API

Energy Technology Data Exchange (ETDEWEB)

Silva, Carlos Eduardo da

2009-07-01

The increase of gas and petroleum demanding in the national and international markets, the specification and certification of the chemical analysis results of gas and oil pipe-line have became more and more challenging. A continuous development has been outlined to improve API grade alloy steels (American Petroleum Institute). The steel properties depend on the chemical composition control and process parameters during its manufacturing. In this work, a comparison of the measurement uncertainty between X-ray fluorescence (WD system) and Optical Emission (OES-spark) spectrometry, for API grade steel plant samples analysis, was outlined. Usually, this kind of analyze requires less than 40 seconds for full chemical characterization for adjustment in the process parameters production. The main influence source in the chemical analysis was evaluated for design of experiments. The constituents and trace elements such as Al, Si, P, S, Ti, V, Cr, Mn, Co, Ni, Cu, As, Nb, Mo and Sn were determined using the ASTM E-322, E-415, E-1009 and E-1085 standard methodologies. The 185A and 187A certified reference materials from CMI (Czech Metrology Institute) were used for evaluation of the methods. The uncertainty of the measurement, precision, accuracy, repeatability and reproducibility of the measurements were obtained applying statistic tests, recommended by ISO/IEC 17025. The uncertainty of measurement for each element is discussed for both techniques. (author)

Fatigue behaviour of friction welded medium carbon steel and austenitic stainless steel dissimilar joints

International Nuclear Information System (INIS)

Paventhan, R.; Lakshminarayanan, P.R.; Balasubramanian, V.

2011-01-01

Research highlights: → Fusion welding of dissimilar metals is a problem due to difference in properties. → Solid state welding process such as friction welding is a solution for the above problem. → Fatigue life of friction welded carbon steel and stainless steel joints are evaluated. → Effect of notch on the fatigue life of friction welded dissimilar joints is reported. → Formation of intermetallic is responsible for reduction in fatigue life of dissimilar joints. -- Abstract: This paper reports the fatigue behaviour of friction welded medium carbon steel-austenitic stainless steel (MCS-ASS) dissimilar joints. Commercial grade medium carbon steel rods of 12 mm diameter and AISI 304 grade austenitic stainless steel rods of 12 mm diameter were used to fabricate the joints. A constant speed, continuous drive friction welding machine was used to fabricate the joints. Fatigue life of the joints was evaluated conducting the experiments using rotary bending fatigue testing machine (R = -1). Applied stress vs. number of cycles to failure (S-N) curve was plotted for unnotched and notched specimens. Basquin constants, fatigue strength, fatigue notch factor and notch sensitivity factor were evaluated for the dissimilar joints. Fatigue strength of the joints is correlated with microstructure, microhardness and tensile properties of the joints.

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.

Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

DEFF Research Database (Denmark)

Hilbert, Lisbeth Rischel

2000-01-01

corrosion rates, when biofilm and corrosion products cover the steel surface. However, EIS might be used for detection of MIC. EN is a suitable technique to characterise the type of corrosion attack, but is unsuitable for corrosion rate estimation. The concentric electrodes galvanic probe arrangement......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...

Hydrogen sulfide corrosion of weld regions in API X52 steel; Corrosion por acido sulfhidrico de las regiones de soldadura en acero API X52

Energy Technology Data Exchange (ETDEWEB)

Arenas-Martinez, L.F [Universidad Autonoma de Coahuila, Coahuila (Mexico)]. E-mail: fernando.arenas@uadec.edu.mx; Garcia-Cerecero, G. [Corporacion Mexicana de Investigacion en Materiales S.A. de C.V., Saltillo, Coahuila (Mexico)

2012-10-15

The corrosion behavior of gas metal arc welding (GMAW) regions has been studied using potentiodynamic polarization and polarization resistance (LPR) techniques. Experiments were conducted in hydrogen sulfide (H{sub 2}S)-containing brine and in H{sub 2}S-free brine. Welds were made on API 5L X52 steel. Due to differences in their microstructure, chemical composition and residual stress level, weld regions exhibited different responses under H{sub 2}S corrosion. Base metal exhibited the highest corrosion rate (CR) and the most cathodic corrosion potential. [Spanish] Se estudio el comportamiento ante la corrosion de las regiones de soldadura de un cordon realizado por arco metalico con gas (GMAW) sobre un acero grado API X52 mediante las tecnicas de polarizacion potencio dinamica y resistencia a la polarizacion (LPR). Los experimentos se realizaron utilizando salmuera con 300 ppm de acido sulfhidrico (H{sub 2}S) y salmuera libre de H{sub 2}S como electrolitos. Debido a las diferencias en su microestructura, composicion quimica y el nivel de esfuerzos residuales, las regiones de soldadura mostraron diferentes respuestas a la corrosion por H{sub 2}S. El metal base exhibio la velocidad de corrosion (VC) mas alta y el potencial de corrosion mas catodico.

Improved corrosion resistance of cast carbon steel in sulphur oxides by Alonizing

International Nuclear Information System (INIS)

Holtzer, M.; Dzioba, Z.

1992-01-01

The results of studies on the Alonizing of cast steel and of testing the corrosion resistance of this cast steel in an atmosphere containing 5 to 6% SO 2 + 50% SO 3 at 853 K are described and compared with the results obtained with unalonized cast carbon steel and high-alloy 23Cr-8Ni-2Mo cast steel. The duration of the corrosion tests was 336 hours. The aluminium diffusion layer on cast carbon steel was obtained by holding the specimens in a mixture containing 99% of powered Fe-Al and 1% of NH 4 Cl at 1323 ± 20 K. The holding time was 10 and 20 hours, respectively. The aluminium layer formed on the cast carbon steel was examined by optical microscopy and an X-ray microanalysis. After Alonizing for 10 h the layer had reached a thickness of 950 μm, and contained up to 35% Al. In a mixture of sulphur oxides corrosion rate of the alonized cast carbon steel was by about 600 times lower than of the unalonized cast carbon steel, and by about 50 times lower than that of the 23Cr-8Ni-2Mo cast steel. (orig.) [de

Processing and refinement of steel microstructure images for assisting in computerized heat treatment of plain carbon steel

Science.gov (United States)

Gupta, Shubhank; Panda, Aditi; Naskar, Ruchira; Mishra, Dinesh Kumar; Pal, Snehanshu

2017-11-01

Steels are alloys of iron and carbon, widely used in construction and other applications. The evolution of steel microstructure through various heat treatment processes is an important factor in controlling properties and performance of steel. Extensive experimentations have been performed to enhance the properties of steel by customizing heat treatment processes. However, experimental analyses are always associated with high resource requirements in terms of cost and time. As an alternative solution, we propose an image processing-based technique for refinement of raw plain carbon steel microstructure images, into a digital form, usable in experiments related to heat treatment processes of steel in diverse applications. The proposed work follows the conventional steps practiced by materials engineers in manual refinement of steel images; and it appropriately utilizes basic image processing techniques (including filtering, segmentation, opening, and clustering) to automate the whole process. The proposed refinement of steel microstructure images is aimed to enable computer-aided simulations of heat treatment of plain carbon steel, in a timely and cost-efficient manner; hence it is beneficial for the materials and metallurgy industry. Our experimental results prove the efficiency and effectiveness of the proposed technique.

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.

Estudo do efeito da tensão sobre a permeação por Hidrogênio em Aços API 5L X60 e API 5L X65

Directory of Open Access Journals (Sweden)

Bruno Araújo Araújo

2017-12-01

Full Text Available Under operating conditions, the oil and gas transmission pipelines can be subjected to high pressures and, at the same time, suffer the effect of acidic substances in the transported hydrocarbons such as H2S, whose action alone or combined with stresses acting in the structure can cause degradation processes of the mechanical properties of the material. Given the importance of the phenomenon, this work has as main objective the realization of hydrogen electrochemical permeation tests in API 5L X60 and API 5L X65 steels under mechanical loading conditions. A device for performing electrochemical permeation tests of hydrogen in the specimens subjected to stress was used for the tests. Thus, it was possible to observe experimentally the influence of stress on the diffusion properties during the experiment. By applying stress on the order of 20% of the yield strength, it was possible to verify the increase of diffusivity of API 5L X60 steel. Furthermore, there was a strong influence of the stress level of permeability, because a large increase of permeability of API 5L X65 steel. The results indicate that the lattice deformation due to imposed mechanical stress has a great influence on the diffusion properties of materials

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.

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

KAUST Repository

Itty, Pierre-Adrien; Serdar, Marijana; Meral, Cagla; Parkinson, Dula; MacDowell, Alastair A.; Bjegović, Dubravka; Monteiro, Paulo J.M.

2014-01-01

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.

Fatigue of carbon and low-alloy steels in LWR environments

International Nuclear Information System (INIS)

Chopra, O.K.; Michaud, W.F.; Shack, W.J.

1994-01-01

Fatigue tests have been conducted on A106-Gr B carbon steel and A533-Gr B low-alloy steel to evaluate the effects of an oxygenated-water environment on the fatigue life of these steels. For both steels, environmental effects are modest in PWR water at all strain rates. Fatigue data in oxygenated water confirm the strong dependence of fatigue life on dissolved oxygen (DO) and strain rate. The effect of strain rate on fatigue life saturates at some low value, e.g., between 0.0004 and 0.001%/s in oxygenated water with ∼0.8 ppm DO. The data suggest that the saturation value of strain rate may vary with DO and sulfur content of the steel. Although the cyclic stress-strain and cyclic-hardening behavior of carbon and low-alloy steels is distinctly different, the degradation of fatigue life of these two steels with comparable sulfur levels is similar. The carbon steel exhibits pronounced dynamic strain aging, whereas strain-aging effects are modest in the low-alloy steel. Environmental effects on nucleation of fatigue crack have also been investigated. The results suggest that the high-temperature oxygenated water has little or not effect on crack nucleation

Aerosol measurements from plasma torch cuts on stainless steel, carbon steel, and aluminum

International Nuclear Information System (INIS)

Novick, V.J.; Brodrick, C.J.; Crawford, S.; Nasiatka, J.; Pierucci, K.; Reyes, V.; Sambrook, J.; Wrobel, S.; Yeary, J.

1996-01-01

The main purpose of this project is to quantify aerosol particle size and generation rates produced by a plasma torch whencutting stainless steel, carbon steel and aluminum. the plasma torch is a common cutting tool used in the dismantling of nuclear facilities. Eventually, other cutting tools will be characterized and the information will be compiled in a user guide to aid in theplanning of both D ampersand D and other cutting operations. The data will be taken from controlled laboratory experiments on uncontaminated metals and field samples taken during D ampersand D operations at ANL nuclear facilities. The plasma torch data was collected from laboratory cutting tests conducted inside of a closed, filtered chamber. The particle size distributions were determined by isokinetically sampling the exhaust duct using a cascade impactor. Cuts on different thicknesses showed there was no observable dependence of the aerosol quantity produced as a function of material thickness for carbon steel. However, data for both stainless steel and aluminum revealed that the aerosol mass produced for these materials appear to have some dependance on thickness, with thinner materials producing tmore aerosols. The results of the laboratory cutting tests show that most measured particle size distributions are bimodal with one mode at about 0.2 μm and the other at about 10 μm. The average Mass Median Aerodynamic Diameters (MMAD's) for these tests are 0.36 ±0.08 μm for stainless steel, 0.48 ±0.17μm for aluminum and 0.52±0.12 μm for carbon steel

Mechanistic studies of carbon steel corrosion inhibition by cashew ...

African Journals Online (AJOL)

The phenoxide, R-Ar-O- ions from the CNSL inhibitor were found to be responsible for the reduction of the corrosion rate of the carbon steel. Also, it was observed that the surface charge of the carbon steel electrodes was positive with respect to the solutions containing CNSL inhibitor. It is likely that the mechanism of the ...

Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

International Nuclear Information System (INIS)

Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo

2016-01-01

The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

Energy Technology Data Exchange (ETDEWEB)

Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo, E-mail: brandao@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Mecanica e de Materiais

2016-09-15

The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

Electrochemical performances of diamond-like carbon coatings on carbon steel, stainless steel, and brass

International Nuclear Information System (INIS)

Hadinata, Samuel-Sudibyo; Lee, Ming-Tsung; Pan, Szu-Jung; Tsai, Wen-Ta; Tai, Chen-Yi; Shih, Chuan-Feng

2013-01-01

Diamond-like carbon (DLC) coatings have been deposited onto stainless steel, carbon steel and brass by plasma-enhanced chemical vapor deposition, respectively. Atomic arrangement, chemical structure, surface morphology and cross-section microstructure of the DLC coatings were examined by X-ray diffraction, Raman scattering spectroscopy and scanning electron microscopy. The electrochemical behaviors of the DLC coatings in 3.5 wt.% NaCl solution were investigated by performing an open circuit potential (OCP) measurement and a potentiodynamic polarization test. The experimental results showed that properly deposited DLC coatings could cause an increase of OCP by hundreds of millivolts and a reduction of anodic current density by several orders of magnitude as compared to that of the substrate. The results also demonstrated that electrochemical techniques could be used as tools to detect the soundness of the DLC coating by examining OCP and polarization curve, which varied with the form of defect and depended on the type of substrate. - Highlights: ► The substrate could affect the quality of diamond-like carbon (DLC) coating. ► Defect-free DLC coating exhibited extremely low anodic current density. ► The quality of DLC coating on metal could be evaluated by electrochemical test

Electrochemical performances of diamond-like carbon coatings on carbon steel, stainless steel, and brass

Energy Technology Data Exchange (ETDEWEB)

Hadinata, Samuel-Sudibyo; Lee, Ming-Tsung [Department of Materials Science and Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Pan, Szu-Jung [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Tsai, Wen-Ta, E-mail: wttsai@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Tai, Chen-Yi [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Shih, Chuan-Feng [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Department of Electrical Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China)

2013-02-01

Diamond-like carbon (DLC) coatings have been deposited onto stainless steel, carbon steel and brass by plasma-enhanced chemical vapor deposition, respectively. Atomic arrangement, chemical structure, surface morphology and cross-section microstructure of the DLC coatings were examined by X-ray diffraction, Raman scattering spectroscopy and scanning electron microscopy. The electrochemical behaviors of the DLC coatings in 3.5 wt.% NaCl solution were investigated by performing an open circuit potential (OCP) measurement and a potentiodynamic polarization test. The experimental results showed that properly deposited DLC coatings could cause an increase of OCP by hundreds of millivolts and a reduction of anodic current density by several orders of magnitude as compared to that of the substrate. The results also demonstrated that electrochemical techniques could be used as tools to detect the soundness of the DLC coating by examining OCP and polarization curve, which varied with the form of defect and depended on the type of substrate. - Highlights: ► The substrate could affect the quality of diamond-like carbon (DLC) coating. ► Defect-free DLC coating exhibited extremely low anodic current density. ► The quality of DLC coating on metal could be evaluated by electrochemical test.

Sustainable Steel Carburization by Using Snack Packaging Plastic Waste as Carbon Resources

Directory of Open Access Journals (Sweden)

Songyan Yin

2018-01-01

Full Text Available In recent years, the research regarding waste conversion to resources technology has attracted growing attention with the continued increase of waste accumulation issues and rapid depletion of natural resources. However, the study, with respect to utilizing plastics waste as carbon resources in the metals industry, is still limited. In this work, an environmentally friendly approach to utilize snack packaging plastic waste as a valuable carbon resources for steel carburization is investigated. At high temperature, plastic waste could be subject to pyrolytic gasification and decompose into small molecular hydrocarbon gaseous products which have the potential to be used as carburization agents for steel. When heating some snack packaging plastic waste and a steel sample together at the carburization temperature, a considerable amount of carbon-rich reducing gases, like methane, could be liberated from the plastic waste and absorbed by the steel sample as a carbon precursor for carburization. The resulting carburization effect on steel was investigated by optical microscopy, scanning electron microscopy, electron probe microanalyzer, and X-ray photoelectron spectrometer techniques. These investigation results all showed that snack packaging plastic waste could work effectively as a valuable carbon resource for steel carburization leading to a significant increase of surface carbon content and the corresponding microstructure evolution in steel.

Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe

Directory of Open Access Journals (Sweden)

Wenhao Wu

2018-01-01

Full Text Available Twin-Wire Pulsed Tandem Gas Metal Arc Welding process with high welding production efficiency was used to join the girth weld seam of API X80 steel linepipe of 18.4 mm wall thickness and 1422 mm diameter. The macrostructure, microstructure, hardness, and electrochemical corrosion behavior of welded joints were studied. Effects of temperature and Cl− concentration on the corrosion behavior of base metal and weld metal were investigated. Results show that the welded joint has good morphology, mechanical properties, and corrosion resistance. The corrosion resistance of both the base metal and the weld metal decreases with increasing temperature or Cl− concentration. In the solution with high Cl− concentration, the base metal and weld metal are more susceptible to pitting. The corrosion resistance of the weld metal is slightly lower than that of the base metal.

Temperature effect on API grade steels in CO{sub 2} environments

Energy Technology Data Exchange (ETDEWEB)

Martins, F.A; Bott, I. [Catholic University of Rio de Janeiro, Metallurgical and Materials Science Department, DCMM/PUC RJ, Rio de Janeiro (Brazil); Rodrigues, A.P.C.; Reznik, L.Y.; Freitas, D.S. de [National Institute of Technology, Corrosion and Degradation Department, DCOR/INT (Brazil)

2004-07-01

There is urgency in optimising and to widen the resources for corrosion control to minimise problems regarding failure and leakage in pipelines. The corrosion control is especially important as it is increasingly associated with mechanical integrity. This means that there is an effort to produce alloys with better mechanical properties which consequently will gradually reduce the thickness of the pipeline walls. However it is necessary to bear in mind that internal corrosion occurs and it can compromise the use of these materials. This is so because as long as the wall thickness is diminished, the corrosion can lead to catastrophic failures and reduce tubes life-time significantly. Therefore, it is necessary to study the behaviour of the steel in critical environments to understand and to obtain a better performance, and moreover, to predict their corrosion rates. The aim of this project is to study the behaviour of the steel X70 and X80 grade, base metal and welded joints, in CO{sub 2} environment. The main focus will be in the stability of iron carbonate film as function of temperature. The methodology of this study will involve several tests and analyses. Electrochemical tests will be carried out in a second part of this work to assess the film formation and to determine, in comparison with gravimetric tests, the corrosion rate. The morphology attack will be determined and metallographic analysis will be carry out to evaluate the steel microstructure. Complementary analysis will be accomplished using SEM/EDX and x-rays diffraction. It is expected to obtain information about the temperature range in which the iron carbonate film on X70 and X80 steels is stable, in such way that it will improve their application. The results of this project will contribute to the leakage control technology in pipelines. Moreover, it will permit a real recommendation of the wall thickness of pipelines to be employed in field, which in return will provide an augment of guarantee in

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...

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Ductile failure analysis of defective API X65 pipes based on stress-modified fracture strain criterion

International Nuclear Information System (INIS)

Oh, Chang Kyun; Kim, Yun Jae; Baek, Jong Hyun; Kim, Young Pyo; Kim, Woo Sik

2006-01-01

A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure for API X65 pipes with gouge defects

Archaeologic analogues: Microstructural changes by natural ageing in carbon steels

International Nuclear Information System (INIS)

Munoz, Esther Bravo; Fernandez, Jorge Chamon; Arasanz, Javier Guzman; Peces, Raquel Arevalo; Criado, Antonio Javier; Dietz, Christian; Martinez, Juan Antonio; Criado Portal, Antonio Jose

2006-01-01

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

Effects of tempering on internal friction of carbon steels

International Nuclear Information System (INIS)

Hoyos, J.J.; Ghilarducci, A.A.; Salva, H.R.; Chaves, C.A.; Velez, J.M.

2011-01-01

Research highlights: → Time tempering dependent microstructure of two steels is studied by internal friction. → Internal friction indicates the interactions of dislocations with carbon and carbides. → Internal friction detects the first stage of tempering. → 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.

Carbon in condensed hydrocarbon phases, steels and cast irons

Directory of Open Access Journals (Sweden)

GAFAROVA Victoria Alexandrovna

2017-11-01

Full Text Available The article presents a review of studies carried out mainly by the researchers of the Ufa State Petroleum Technological University, which are aimed at detection of new properties of carbon in such condensed media as petroleum and coal pitches, steels and cast irons. Carbon plays an important role in the industry of construction materials being a component of road and roof bitumen and setting the main mechanical properties of steels. It was determined that crystal-like structures appear in classical glass-like substances – pitches which contain several thousands of individual hydrocarbons of various compositions. That significantly extends the concept of crystallinity. In structures of pitches, the control parameter of the staged structuring process is paramagnetism of condensed aromatic hydrocarbons. Fullerenes were detected in steels and cast irons and identified by various methods of spectrometry and microscopy. Fullerene С60, which contains 60 carbon atoms, has diameter of 0,7 nm and is referred to the nanoscale objects, which have a significant influence on the formation of steel and cast iron properties. It was shown that fullerenes appear at all stages of manufacture of cast irons; they are formed during introduction of carbon from the outside, during crystallization of metal in welded joints. Creation of modified fullerene layers in steels makes it possible to improve anticorrosion and tribological properties of structural materials. At the same time, outside diffusion of carbon from the carbon deposits on the metal surface also leads to formation of additional amount of fullerenes. This creates conditions for occurrence of local microdistortions of the structure, which lead to occurrence of cracks. Distribution of fullerenes in iron matrix is difficult to study as the method is labor-intensive, it requires dissolution of the matrix in the hydrofluoric acid and stage fullerene separation with further identification by spectral methods.

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. Copyright © 2014. Published by Elsevier B.V.

Plasticity of low carbon stainless steels

International Nuclear Information System (INIS)

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

1975-01-01

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

A study of the condition for the passivation of carbon steel in bentonite

International Nuclear Information System (INIS)

Taniguchi, Naoki; Morimoto, Masataka; Honda, Akira

1999-01-01

It is important to study the corrosion behavior of materials to be used for overpack for high-level radioactive waste disposal. Carbon steel is one of the candidate materials. The type of corrosion on carbon steel depends on whether the carbon steel is passivated or not. In this study, the condition for the passivation of carbon steel was studied using bentonite as the buffer material. Anodic polarization in bentonite and the measurements of pH of porewater in bentonite was measured. The results of these experiments showed that the possibility of passivation is small in highly compacted bentonite in groundwater in Japan. Therefore, localized corrosion on carbon steel due to the breakdown of passive film is unlikely in bentonite. In other words, general corrosion seems to be the most probable type of corrosion under repository condition in Japan. (author)

Medium carbon vanadium steels for closed die forging

International Nuclear Information System (INIS)

Jeszensky, Gabor; Plaut, Ronald Lesley

1993-01-01

This work analyses the medium carbon micro alloyed vanadium potential for closed die forged production. The steels reach the mechanical resistance requests during cooling after forging, eliminating the subsequent thermal treatment. Those steels also present good fatigue resistance and machinability. The industrial scale experiments are also reported

Analysis of heat transfer in plain carbon steels

International Nuclear Information System (INIS)

Han, Heung Nam; Lee, Kyung Jong

1999-01-01

During cooling of steels, the heat transfer was controlled by radiation, convection, conduction and heat evolution from phase transformation. To analyze the heat transfer during cooling precisely, the material constants such as density, heat capacity and the heat evolved during transformation were obtained as functions of temperature and chemical composition for each phase observed in plain carbon steel using a thermodynamic analysis based on the sublattice model of Fe-C-Mn system. The results were applied to 0.049 wt% and 0.155 wt% carbon steels with an austenitic stainless steel as reference by developing a proper heat transfer governing equation. The equation was solved using the lumped system method. In addition, using a transformation dilatometer with adequate experimental conditions to clarify the individual heat transfer effect, the transformation heat evolved during cooling and the transformation behavior as well as the temperature change were observed. The predicted temperature profiles during cooling were well agreed with the measured ones

Ferrite morphology and residual phases in continuously cooled low carbon steels

International Nuclear Information System (INIS)

Dunne, D.P.

1999-01-01

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

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

Science.gov (United States)

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

2017-05-01

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

Interface Analyses Between a Case-Hardened Ingot Casting Steel and Carbon-Containing and Carbon-Free Refractories

Science.gov (United States)

Fruhstorfer, Jens; Dudczig, Steffen; Rudolph, Martin; Schmidt, Gert; Brachhold, Nora; Schöttler, Leandro; Rafaja, David; Aneziris, Christos G.

2018-06-01

Corrosion tests of carbon-free and carbon-containing refractories were performed. The carbon-free crucibles corroded, whereas the carbon-containing crucibles were negligibly attacked. On them, inclusions were attached. This study investigates melt oxygen contents, interface properties, and steel compositions with their non-metallic inclusions in order to explore the inclusion formation and deposition mechanisms. The carbon-free crucibles were based on alumina, mullite, and zirconia- and titania-doped alumina (AZT). The carbon-containing (-C) ones were alumina-C and AZT-C. Furthermore, nanoscaled carbon and alumina additives (-n) were applied in an AZT-C-n material. In the crucibles, the case-hardened steel 17CrNiMo7-6 was remelted at 1580 °C. It was observed that the melt and steel oxygen contents were higher for the tests in the carbon-free crucibles. Into these crucibles, the deoxidizing alloying elements Mn and Si diffused. Reducing contents of deoxidizing elements resulted in higher steel oxygen levels and less inclusions, mainly of the inclusion group SiO2-core-MnS-shell (2.5 to 8 μ m). These developed from smaller SiO2 nuclei. The inclusion amount in the steel was highest after remelting in AZT-C-n for 30 minutes but decreased strongly with increasing remelting time (60 minutes) due to inclusions' deposition on the refractory surface. The Ti from the AZT and the nanoadditives supported inclusion growth and deposition. Other inclusion groups were alumina and calcium aluminate inclusions. Their contents were high after remelting in carbon- or AZT-containing crucibles but generally decreased during remelting. On the AZT-C-n crucible, a dense layer formed from vitreous compositions including Al, Ca, Mg, Si, and Ti. To summarize, for reducing forming inclusion amounts, mullite is recommended as refractory material. For capturing formed inclusions, AZT-C-n showed a high potential.

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-04-25

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

Corrosion behaviour of carbon steel in the Tournemire clay

International Nuclear Information System (INIS)

Foct, F.; Dridi, W.; Cabrera, J.; Savoye, S.

2004-01-01

Carbon steels are possible materials for the fabrication of nuclear waste containers for long term geological disposal in argillaceous environments. Experimental studies of the corrosion behaviour of such materials has been conducted in various conditions. Concerning the numerous laboratory experiments, these conditions (water and clay mixture or compacted clay) mainly concern the bentonite clay that would be used for the engineered barrier. On the opposite, only few in-situ experiments has been conducted directly in the local clay of the repository site (such as Boom clay, etc.). In order to better estimate the corrosion behaviour of carbon steels in natural clay site conditions, an experimental study has been conducted jointly by EDF and IRSN in the argillaceous French site of Tournemire. In this study, A42 carbon steel specimens have been exposed in 3 different zones of the Tournemire clay formation. The first type of environmental conditions concerns a zone where the clay has not been affected by the excavation (EDZ) of the main tunnel neither by the main fracture zone of the clay formation. The second and third ones are located in the EDZ of the tunnel. In the second zone, an additional aerated water flows from the tunnel, whereas it does not in the third place. Some carbon steel specimens have been extracted after several years of exposure to these conditions. The average corrosion rate has been measured by the weight loss technique and the pitting corrosion depth has been evaluated under an optical microscope. Corrosion products have also been characterised by scanning electron microscopy and X-ray diffraction technique. Results are then discussed regarding the surrounding environmental conditions. Calculations of the oxygen transport from the tunnel through the clay and of the clay re-saturation can explain, in a first approach, the corrosion behaviour of the carbon steel in the different tested zones. (authors)

Coupled gamma/alpha phase transformations in low-carbon steels

Science.gov (United States)

Mizutani, Yasushi

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

Gaseous hydrogen embrittlement of an API X80 ferrito-pearlitic steel; Fragilisation par l'hydrogene gazeux d'un acier ferrito-perlitique de grade API X80

Energy Technology Data Exchange (ETDEWEB)

Moro, I.

2009-11-15

This work deals with hydrogen embrittlement, at ambient temperature and under a high pressure gaseous way, of an API X80 high elasticity limit steel used for pipelines construction, and with the understanding of the associated physical mechanisms of the embrittlement. At first has been described a bibliographic study of the adsorption, absorption, diffusion, transport and trapping of hydrogen in the steels. Then has been carried out an experimental and numerical study concerning the implantation in the finite element code CASTEM3M of a hydrogen diffusion model coupled to mechanical fields. The hydrogen influence on the mechanical characteristics of the X80 steel, of a ferrito-pearlitic microstructure has been studied with tensile tests under 300 bar of hydrogen and at ambient temperature. The sensitivity of the X80 steel to hydrogen embrittlement has been analyzed by tensile tests at different deformation velocities and under different hydrogen pressures on axisymmetrical notched test specimens. These studies show that the effect of the hydrogen embrittlement vary effectively with the experimental conditions. Moreover, correlated with the results of the tests simulations, it has been shown too that in these experimental conditions and for that steel, the hydrogen embrittlement is induced by three different hydrogen populations: the hydrogen trapped at the ferrite/perlite interfaces, the hydrogen adsorbed on surface and the reticular hydrogen trapped in the material volume. At last, the tensile and rupture tests of specimens, during which atmosphere changes have been carried out, have shown a strong reversibility of the hydrogen embrittlement, associated with its initiation as soon as hydrogen is introduced in the atmosphere. At last, three hydrogen mechanisms, depending of the different hydrogen populations are presented and discussed. (O.M.)

Corrosion behaviour of dissimilar welds between martensitic stainless steel and carbon steel from secondary circuit of candu npp

International Nuclear Information System (INIS)

Popa, L.; Fulger, M.; Tunaru, M.; Velciu, L.; Lazar, M.

2015-01-01

Corrosion damages of welds occur in spite of the fact that the proper base metal and filler metal have been correctly selected, industry codes and standards have been followed and welds have been realized with full weld penetration and have proper shape and contour. It is not unusual to find that, although the base metal or alloy is resistant to corrosion in a particular environment, the welded counterpart is not resistant. In secondary circuit of a Nuclear Power Station there are some components which have dissimilar welds. Our experiments were performed in chloride environmental on two types of samples: non-welded (420 martensitic steel and 52.2k carbon steel) and dissimilar welds (dissimilar metal welds: joints beetween 420 martensitic steel and 52.2k carbon steel). To evaluate corrosion susceptibility of dissimilar welds was used electrochemical method (potentiodynamic method) and metallography microscopy (microstructural analysis). The present paper follows the localized corrosion behaviour of dissimilar welds between austenitic stainless steel and carbon steel in solutions containing chloride ions. We have been evaluated the corrosion rates of samples (welded and non-welded) by electrochemically. (authors)

Influence of the maximum applied magnetic field on the angular dependence of Magnetic Barkhausen Noise in API5L steels

Energy Technology Data Exchange (ETDEWEB)

Martínez-Ortiz, P. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F. (Mexico); Pérez-Benítez, J.A., E-mail: japerezb@ipn.mx [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F. (Mexico); Espina-Hernández, J.H. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F. (Mexico); Caleyo, F. [Departamento de Ingeniería Metalúrgica, ESIQIE, UPALM Edif. 7, Instituto Politécnico Nacional, Zacatenco, C.P. 07738 México D.F. (Mexico); Mehboob, N.; Grössinger, R. [Institute of Solid State Physics, Vienna University of Technology, Vienna A-1040 (Austria); Hallen, J.M. [Departamento de Ingeniería Metalúrgica, ESIQIE, UPALM Edif. 7, Instituto Politécnico Nacional, Zacatenco, C.P. 07738 México D.F. (Mexico)

2016-03-01

This work studies the influence of the maximum applied magnetic field on the angular dependence of the energy of the Magnetic Barkhausen Noise signal in three different API5L pipeline steels. The results show that the shape of the angular dependence of the Magnetic Barkhausen Noise energy changes with the increase of the amplitude of the applied magnetic field. This phenomenon is a consequence of the presence of unlike magnetization processes at different magnitudes of the applied magnetic field. The outcomes reveal the importance of controlling the value of the maximum applied field as parameter for the improvement of the MBN angular dependence measurements. - Highlights: • Study the angular dependence of MBN with applied field in three pipeline steels. • Reveals the change of this angular dependence with the increase applied field. • Explains this dependence based on the domain wall dynamics theory.

Influence of the maximum applied magnetic field on the angular dependence of Magnetic Barkhausen Noise in API5L steels

International Nuclear Information System (INIS)

Martínez-Ortiz, P.; Pérez-Benítez, J.A.; Espina-Hernández, J.H.; Caleyo, F.; Mehboob, N.; Grössinger, R.; Hallen, J.M.

2016-01-01

This work studies the influence of the maximum applied magnetic field on the angular dependence of the energy of the Magnetic Barkhausen Noise signal in three different API5L pipeline steels. The results show that the shape of the angular dependence of the Magnetic Barkhausen Noise energy changes with the increase of the amplitude of the applied magnetic field. This phenomenon is a consequence of the presence of unlike magnetization processes at different magnitudes of the applied magnetic field. The outcomes reveal the importance of controlling the value of the maximum applied field as parameter for the improvement of the MBN angular dependence measurements. - Highlights: • Study the angular dependence of MBN with applied field in three pipeline steels. • Reveals the change of this angular dependence with the increase applied field. • Explains this dependence based on the domain wall dynamics theory.

Improvement of deposition efficiency and control of hardness for cold-sprayed coatings using high carbon steel/mild steel mixture powder

International Nuclear Information System (INIS)

Ogawa, Kazuhiro; Amao, Satoshi; Yokoyama, Nobuyuki; Ootaki, Kousuke

2011-01-01

In this study, in order to make high carbon steel coating by cold spray technique, spray conditions such as carrier gas temperature and pressure etc. were investigated. And also, in order to improve deposition efficiency and control coating hardness of cold-sprayed high carbon steel, high carbon and mild steel mixed powder and its mechanical milled powder were developed and were optimized. By using the cold-spray technique, particle deposition of a high carbon steel was successful. Moreover, by applying mixed and mechanical milled powders, the porosity ratio was decreased and deposition efficiency was improved. Furthermore, using these powders, it is possible to control the hardness value. Especially, when using mechanical milled powder, it is very difficult to identify the interface between the coating and the substrate. The bonding between the coating and the substrate is thus considered to be excellent. (author)

Content of nitrogen in waste petroleum carbon for steel industries

International Nuclear Information System (INIS)

Rios, R.O; Jimenez, A.F; Szieber, C.W; Banchik, A.D

2004-01-01

Steel industries use refined carbon as an alloy for steel production. This alloy is produced from waste carbon from the distillation of the petroleum. The refined carbon, called recarburizer, is obtained by calcination at high temperature. Under these thermal conditions the organic molecules decompose and a fraction of the N 2 , S and H 2 , volatile material and moisture are released; while the carbon tends to develop a crystalline structure similar to graphite's. The right combination of calcinations temperature and time in the furnace can optimize the quality of the resulting product. The content of S and N 2 has to be minimized for the use of calcined carbon in the steel industry. Nitrogen content should be reduced by two orders of magnitude, from 1% - 2% down to hundreds of ppm by weight. This work describes the activities undertaken to obtain calcined coke from petroleum from crude oil carbon that satisfies the requirements of the Mercosur standard 02:00-169 (Pending) for use as a carborizer in steels industries. To satisfy the requirements of the Mercosur standards NM 236:00 IRAM-IAS-NM so that graphite is used as a carburizer a content of 300 ppm maximum weight of nitrogen has to be obtained. So the first stage in this development is to define a production process for supplying calcined coke in the range of nitrogen concentrations required by the Mercosur standards (CW)

Accelerated Carbonation of Steel Slag Compacts: Development of High-Strength Construction Materials

Energy Technology Data Exchange (ETDEWEB)

Quaghebeur, Mieke; Nielsen, Peter, E-mail: peter.nielsen@vito.be; Horckmans, Liesbeth [Sustainable Materials Management, VITO, Mol (Belgium); Van Mechelen, Dirk [RECMIX bvba, Genk (Belgium)

2015-12-17

Mineral carbonation involves the capture and storage of carbon dioxide in carbonate minerals. Mineral carbonation presents opportunities for the recycling of steel slags and other alkaline residues that are currently landfilled. The Carbstone process was initially developed to transform non-hydraulic steel slags [stainless steel (SS) slag and basic oxygen furnace (BOF) slags] in high-quality construction materials. The process makes use of accelerated mineral carbonation by treating different types of steel slags with CO{sub 2} at elevated pressure (up to 2 MPa) and temperatures (20–140°C). For SS slags, raising the temperature from 20 to 140°C had a positive effect on the CO{sub 2} uptake, strength development, and the environmental properties (i.e., leaching of Cr and Mo) of the carbonated slag compacts. For BOF slags, raising the temperature was not beneficial for the carbonation process. Elevated CO{sub 2} pressure and CO{sub 2} concentration of the feed gas had a positive effect on the CO{sub 2} uptake and strength development for both types of steel slags. In addition, the compaction force had a positive effect on the strength development. The carbonates that are produced in situ during the carbonation reaction act as a binder, cementing the slag particles together. The carbonated compacts (Carbstones) have technical properties that are equivalent to conventional concrete products. An additional advantage is that the carbonated materials sequester 100–150 g CO{sub 2}/kg slag. The technology was developed on lab scale by the optimization of process parameters with regard to compressive strength development, CO{sub 2} uptake, and environmental properties of the carbonated construction materials. The Carbstone technology was validated using (semi-)industrial equipment and process conditions.

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

Science.gov (United States)

Hafni; Hadi, Syafrul; Edison

2017-12-01

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

Internal friction in martensitic carbon steels

International Nuclear Information System (INIS)

Hoyos, J.J.; Ghilarducci, A.A.; Salva, H.R.; Chaves, C.A.; Velez, J.M.

2009-01-01

This paper proposes relationships between the internal friction and the microstructure of two steels containing 0.626 and 0.71 wt.% carbon. The steels were annealed at 1093 K for 5 min, quenched into water and tempered for 10 min at 423, 573 and 723 K. Internal friction was measured by using a forced vibration pendulum, in a temperature range from 100 to 450 K. The internal friction spectrum is decomposed into four peaks: P1 at 215 K, P2 at 235 K, P3 at 260 K and P4 at 380 K for 3 Hz. Peak P1 is attributed to the interactions between dislocations and carbon atoms. Peak P2 is related to the interaction between dislocations and carbide. Peak P3 is related to the generations of kink - pairs along edge dislocations. Peak P4 is attributed to epsilon carbide precipitation.

Electroslag welding of rotor steels produced with vacuum-carbon reduction

International Nuclear Information System (INIS)

Roshchin, M.B.; Modzhuk, M.D.; Izvekov, B.V.

1985-01-01

Metallurgical processes of electroslag welding of rotor steels, melted with vacuum-carbon deoxidation, have been considered. It is established, that during electroslag welding of steels with carbon content 0.20...0.30%, suppression of welding bath boiling and production of dense weld metal with a high impact strength can be ensured at oxygen concentration in soldered on metal not exceeding 0.01% and silicon content 0.06...0.10%

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.

Bainite formation kinetics in high carbon alloyed steel

International Nuclear Information System (INIS)

Luzginova, N.V.; Zhao, L.; Sietsma, J.

2008-01-01

In recent years, many investigations have been carried out on the modeling of the bainite formation. In the present work, a physical approach proposed in the literature is implemented to model the formation of lower bainite in high carbon steels (1 wt.% C). In this model, the carbon diffusion is assumed to control the kinetics of the bainite formation. Both the nucleation and the growth rates are considered in an Avrami type analysis. The effect of alloying elements is taken into account considering only the thermodynamics of the system. The results and the physical meaning of the model parameters are discussed. It is shown that the diffusional approach gives a reasonable description of bainite formation kinetics in high carbon steel. Only two fitting parameters are used: the first accounts for carbon grain-boundary diffusion and the second is the initial nucleation-site density. The model satisfactorily accounts for the effect of transformation temperature, but does not take into account the carbide precipitation during bainite formation and the effect of alloying elements on the diffusion coefficient of carbon

Carbon steel protection in G.S. (Girlder sulfide) plants. CITROSOLV process influence. Pt. 6

International Nuclear Information System (INIS)

Lires, O.A.; Burkart, A.L.; Delfino, C.A.; Rojo, E.A.

1988-01-01

In order to protect carbon steel towers and piping of Girlder sulfide (G.S.) experimental heavy water plants against corrosion produced by the action of aqueous solutions of hydrogen sulfides, a method, previously published, was developed. Carbon steel, exposed to saturated aqueous solutions of hydrogen sulfide, forms iron sulfide scales. In oxygen free solutions evolution of corrosion follows the sequence: mackinawite → cubic ferrous sulfide → troilite → pyrrotite → pyrite. Scales formed by pyrrotite-pyrite or pyrite are the most protective layers (these are obtained at 130 deg C, 2 MPa, for periods of 14 days). CITROSOLV Process (Pfizer) is used to descaling and passivating stainless steel plant's components. This process must be used in mixed (carbon steel - stainless steel) circuits and may cause the formation of magnetite scales over the carbon steel. The influence of magnetite in the pyrrotite-pyrite scales formation is studied in this work. (Author) [es

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.

Electrochemical noise from corroding carbon steel and aluminium

International Nuclear Information System (INIS)

Singh, P.R.; Gaonkar, K.B.; De, P.K.; Banerjee, S.

1997-05-01

Electrochemical noise measurements were conducted on carbon steel and aluminium in sodium chloride solutions. Noise parameters like standard deviation of potential and current, noise resistance, pitting index, noise power were studied for the purpose of measuring corrosion rate. These parameters compared well with the corrosion rate. Pitting index was not very reliable. Current noise was more close to the corrosion rates. General corrosion gave rise to white noise type of power spectrum while flicker noise type of spectrum was obtained from pitting attack. Sodium nitrite is shown to inhibit the corrosion of carbon steel. Aluminium corrodes in the early period of exposure and passivates during long exposure

Corrosion study of API 5L x-series pipeline steels in 3.5% NaCl solution under varying conditions

International Nuclear Information System (INIS)

Shahid, M.; Qureshi, M.I.; Farooq, M.U.; Khan, M.I.

2003-01-01

Pipelines provide convenient and efficient means for mass transportation of variety of fluids, such as oil and gas, over varying distances. In the last two decades or so, pipeline designers focused mainly on the usage of larger sizes and higher operating pressures for achieving higher transportation efficiency. This has been accomplished through the provision of steels with progressive increase in yield strength coupled with good weldability and sufficient toughness to restrict crack propagation. In addition to higher strength and toughness, developing pipeline technologies have required improved resistance to corrosion, which has been tried with specific alloy additions and special control over non-metallic inclusions. Corrosion investigations were carried out on various grades of pipeline steels (API 5L X-46, X-52, X-56, X-60 and X- 70) under varying environmental conditions. This paper describes the results pertaining to corrosion behavior of the steels in 3.5% NaCl solutions in stagnant, turbulent and deaerated conditions. It was found that all grades corrode in this solution and their corrosion potentials and corrosion currents are in close vicinity of each other. Turbulent solutions, however, have shown an increase in corrosion rates whereas deaeration has revealed a relative decrease in aggressivity of the electrolyte. (author)

Corrosion Protection of Carbon Steel Using Poly aniline Composite with Inorganic Pigments

International Nuclear Information System (INIS)

Al-Dulaimi, A.A.; Shahrir Hashim; Khan, M.I.

2011-01-01

Two inorganic pigments (TiO 2 and SiO 2 ) were used to prepare composites with poly aniline (PANI) by situ polymerization method. PANI and PANI composites with SiO 2 and TiO 2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO 2 and PANI-TiO 2 ) was examined using scanning electron microscopy. Samples were then used as pigments through blending them with acrylic paint and applied on the surface of carbon steel panels. Corrosion was evaluated for coating of carbon steel panels through full immersion test up to standard ASTMG 31. Mass loss was calculated after they have been exposed in acidic media. A digital camera was also used for monitoring corrosion visually on the surface of carbon steel specimens. The results revealed that acrylic paint pigmented by PANI-SiO 2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments. (author)

Damascus steels: history, processing, properties and carbon dating

International Nuclear Information System (INIS)

Wadsworth, J.

2007-01-01

In the mid-1970s, a class of steels containing high levels of carbon (∼ 1-2 wt% C) was developed for superplastic characteristics - that is, the ability to plastically deform to an extraordinary degree in tension at intermediate temperatures. Because these steels also had excellent room temperature properties, they were developed for their commercial potential. In the late 1970s, we became aware of the striking compositional similarities between these modern steels and the ancient steels of Damascus. This observation led us to revisit the history and metallurgy of Damascus steels and related steels. The legends and origins of Damascus steel date back to the time of Alexander the Great (323 BC) and the medieval Crusades (11th and 12th century AD), and this material has also been the subject of scrutiny by famous scientist in Europe, including Michael Faraday. Modern attempts to reproduce the legendary surface patterns which famously characterized Damascus steels are described. The extend to which the characteristics of Damascus steels are unusual is discussed. Finally, a program on radiocarbon dating was initiated to directly determine the age of about 50 ancient steels, including a Damascus knife, and the results are summarized. (author)

The effects of bacteria on the corrosion behavior of carbon steel in compacted bentonite

International Nuclear Information System (INIS)

Nishimura, T.; Wada, R.; Nishimoto, H.; Fujiwara, K.; Taniguchi, N.; Honda, A.

1999-10-01

As a part of evaluation of corrosion life of carbon steel overpack, the experimental studies have been performed on the effects of bacteria on the corrosion behavior of carbon steel in compacted bentonite using iron bacteria (IB) as a representative oxidizing bacteria and sulphur reducing bacteria (SRB) as a representative reducing bacteria. The results of the experimental studies showed that; The activity of SRB was low in compacted bentonite in spite of applying suitable condition for the action of bacteria such as temperature and nutritious solution. Although the corrosion behavior of carbon steel was affected by the existence of bacteria in simple solution, the corrosion rates of carbon steel in compacted bentonite were several μ m/year -10 μ m/year irrespective of coexistence of bacteria and that the corrosion behavior was not affected by the existence of bacteria. According to these results, it was concluded that the bacteria would not affect the corrosion behavior of carbon steel overpack under repository condition. (author)

Study of API 5L X70 steel corrosion processes when in contact with some Brazilian soils

International Nuclear Information System (INIS)

Jesus, Sergio Luis de

2007-01-01

Pipelines, fuel storage tanks and other metallic structures are in permanent contact and exposed to different types of soils, of horizons or layers, or of soil aggressiveness. This interaction may cause expressive damages to the environment and to the planned work. Contamination may occur due to leakage of stored products, splitting during transportation, accidents caused by pipelines without extensive maintenance. The result of these accidents could be, among others, some financial losses. In order to recognize the dynamic interactions between metallic surfaces and the environment it is crucial to have preventive actions and to develop better-applied materials. API steel 5L X70 has been used in structures of low and high pressure with high mechanical strength and corrosion and, even so, it is susceptible to etching corrosion since it is in contact with different environments from mangrove regions to industrial environments. The present case evaluated the role of 5L X70 API steel in contact with different soil horizons representative of the Brazilian soil. This investigation correlated chemical species with solute ions in soil solution, secondary and primary phase minerals besides physical and chemical characteristics as pH, electric conductivity, total dissolved solids, among others, to the results of corrosion resistance and ways of corrosion. The evaluation was carried out using x-ray diffractometry, scanning electron microscopy, total reflection x-ray fluorescence, fuel injection flow besides texture and gravimetric analyses to soil characterization and mineralogy, identification of corrosion products, soil solution analyses, evaluation of tested materials and classification of ways and types of corrosion. This was an attempt to integrate the data to a better understanding of the process involving reagents and products. The results showed that different soil horizons such as different types of analyzed soils produce specific etching in metallic structures

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.

Modification of steel surface by plasma electrolytic saturation with nitrogen and carbon

Energy Technology Data Exchange (ETDEWEB)

Kusmanov, S.A., E-mail: sakusmanov@yandex.ru; Kusmanova, Yu.V., E-mail: yulia.kusmanova@yandex.ru; Smirnov, A.A., E-mail: sciencealexsm@gmail.com; Belkin, P.N., E-mail: belkinp@yandex.ru

2016-06-01

The effect of the electrolyte composition with ammonia, acetone, and ammonium chloride on the structure and properties of low carbon steel was studied in anode plasma electrolytic nitrocarburising. An X-ray diffractometer, a scanning electron microscopy (SEM) and an optical microscope were used to characterize the phase composition of the modified layer and its surface morphology. Surface roughness was studied with a profilometer–profilograph. The hardness of the treated and untreated samples was measured using a microhardness tester. The sources of nitrogen and carbon are shown to be the products of evaporation and thermal decomposition of the electrolyte components. It is established that the influence of concentration of ammonia, acetone, and ammonium chloride on the size of the structural components of the hardened layer is explained by the competition of the anode dissolution, high-temperature oxidation and diffusion of the saturating component. The electrolyte composition (10–12.5% ammonium chloride, 5% acetone, 5% ammonia) and processing mode (800 °C, 5–10 min) of low carbon steels allowing to obtain the hardened surface layer up to 0.2 mm with microhardness 930 HV and with decrease in the roughness (R{sub a}) from 1.013 to 0.054 μm are proposed. The anode plasma electrolytic nitricarburising is able to decrease friction coefficient of the treated low carbon steel from 0.191 to 0.169 and wear rate from 13.5 mg to 1.0 mg. - Highlights: • Aqueous solution (12.5% NH{sub 4}Cl, 5% ammonia, 5% acetone) is proposed for PEN/C steels. • Microhardness of steel (0.2% C) is 930 HV due to PEN/C for 5–10 min at 800 °C. • Anode PEN/C of low carbon steel decreases its roughness (R{sub a}) from 1.013 to 0.054 μm. • Anode PEN/C decreases friction coefficient of low carbon steel from 0.191 to 0.169 • Anode PEN/C decreases wear loss of low carbon steel from 13.5 mg to 1.0 mg.

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.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-01-15

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

Estudo do comportamento do aço API 5L X80 quando submetido à soldagem por processo automatizado Study on the behavior of API 5L X80 steel when subjected to automated welding process

Directory of Open Access Journals (Sweden)

Siderley Fernandes Albuquerque

2012-06-01

Full Text Available No Brasil, a soldagem de tubulações tem sido praticamente de forma manual, entretanto, a utilização de processos de soldagem automatizados têm crescido muito nos últimos anos, contribuindo para o maior controle dos parâmetros de soldagem, e conseqüentemente, a possibilidade de obtenção de juntas soldadas com melhores propriedades mecânicas. A soldagem de tubulações com aço API 5L X80 ainda vem sendo avaliada no Brasil no que diz respeito aos melhores procedimentos, parâmetros e processos de soldagem; a aplicação de processos automatizados nas condições específicas de campo constitui em uma opção ainda incipiente no país por se discutir ainda a relação custo/benefício com a sua implantação. Logo, o objetivo deste trabalho é avaliar o comportamento na ZTA de juntas soldadas do aço API 5L X80 utilizados para transporte de petróleo e gás quando submetidos à soldagem com diferentes parâmetros, procedimentos e processos de soldagem, incluindo o processo automatizado; os resultados indicam além da redução da extensão e do tamanho de grão da ZTA a preservação da estrutura bainítica do metal de base nesta região nas soldagem executadas com processos automatizados.The welding of pipes has been largely manual in Brazil, however, the use of automated welding processes have greatly increased in recent years, contributing to greater control of welding parameters, and consequently, the possibility of obtaining welded joints with better mechanical properties. The welding of pipes of API 5L X80 steel has been evaluated in Brazil considering to best practices, parameters and welding processes; the implementation of automated processes in the specific field conditions is relevant project and innovative design in this area. Therefore, the objective is to evaluate the behavior in the HAZ of the API 5L X80 steel used for transporting oil and gas when subjected to automated welding processes; the results indicated besides the

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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.

Study of an API migration for two XML APIs

NARCIS (Netherlands)

T.T. Bartholomei; K. Czarnecki; R. Lämmel (Ralf); T. van der Storm (Tijs); M.G.J. van den Brand (Mark); D. Gasevic; J. Gray

2010-01-01

htmlabstractAPI migration refers to adapting an application such that its dependence on a given API (the source API) is eliminated in favor of depending on an alternative API (the target API) with the source and target APIs serving the same domain. One may attempt to automate API migration by code

The Effects of Cr and Al Addition on Transformation and Properties in Low‐Carbon Bainitic Steels

Directory of Open Access Journals (Sweden)

Junyu Tian

2017-01-01

Full Text Available Three low‐carbon bainitic steels were designed to investigate the effects of Cr and Al addition on bainitic transformation, microstructures, and properties by metallographic method and dilatometry. The results show that compared with the base steel without Cr and Al addition, only Cr addition is effective for improving the strength of low‐carbon bainitic steel by increasing the amount of bainite. However, compared with the base steel, combined addition of Cr and Al has no significant effect on bainitic transformation and properties. In Cr‐bearing steel, Al addition accelerates initial bainitic transformation, but meanwhile reduces the final amount of bainitic transformation due to the formation of a high‐temperature transformation product such as ferrite. Consequently, the composite strengthening effect of Cr and Al addition is not effective compared with individual addition of Cr in low‐carbon bainitic steels. Therefore, in contrast to high‐carbon steels, bainitic transformation in Cr‐bearing low‐carbon bainitic steels can be finished in a short time, and Al should not be added because Al addition would result in lower mechanical properties.

Corrosion Cyclic Voltammetry of Two Types of Heat-Affected Zones (HAZs) of API-X100 Steel in Bicarbonate Solutions

Science.gov (United States)

Eliyan, Faysal Fayez; Alfantazi, Akram

2014-12-01

This paper examined the electrochemical corrosion behavior and corrosion products of two types of heat-affected HAZs made from API-X100 steel. Cyclic voltammetry, with different scan rates and potential ranges at 10 cycles, was applied to analyze the interdependent corrosion reactions of cathodic reduction, anodic dissolution, passivation, and transpassivation. The HAZ cooled at 60 K/s, from a peak temperature of 1470 K (1197 °C) that was held for 15 seconds, exhibited better passivation and lower cathodic activity than the HAZ cooled at 10 K/s. Increasing bicarbonate concentration, from 0.05 and 0.2 to 0.6 M, increases the anodic activity and cathodic reduction, but accordingly protects the active surfaces and enhances passivation.

Tribological performance of hard carbon coatings on 440C bearing steel

Energy Technology Data Exchange (ETDEWEB)

Kustas, F M; Misra, M S; Shepard, D F; Froechtenigt, J F [Martin Marietta Astronautics Group, Denver, CO (United States)

1991-11-01

Hard carbon coatings such as amorphous carbon, diamond and diamond-like carbon have received considerable attention for tribological applications owing to their high hardness, high modulus and desirable surface properties. Unfortunately, most of the deposition techniques induce high substrate temperatures that would temper traditional bearing steels and reduce the substrate load-carrying capability. Therefore, to effectively use these desirable coatings, a lower temperature deposition technique is required. Ion beam deposition can provide essentially ambient temperature conditions, accurate control of process parameters and good coating-substrate adhesion. To use these attributes, a test program was initiated to deposit mass-analyzed, high purity C{sup +} and CH{sub 4}{sup +} ions on molybdenum and 440C bearing steel for subsequent characterization by Raman spectroscopy and friction-wear tests. Results for a coating deposited from a carbon monoxide source showed an amorphous carbon-microcrystalline graphtie structure which exhibited very high microhardness and a three fold reduction in coefficient of friction for unlubricated tests compared to untreated 440C steel. In addition, incrementally increasing the applied load (by up to a factor of 5) resulted in progressively lower coefficients of friction, which conforms to solid lubrication theory. End-of-travel wear debris and some limited coating delamination were observed within thinner areas of the coating. Therefore an amorphous carbon-graphite coating applied to 440C steel at ambient temperature exhibits solid lubricating film characteristics with high load-carrying capability. (orig.).

Effect of small addition of Cr on stability of retained austenite in high carbon steel

Energy Technology Data Exchange (ETDEWEB)

Hossain, Rumana; Pahlevani, Farshid, E-mail: f.pahlevani@unsw.edu.au; Sahajwalla, Veena

2017-03-15

High carbon steels with dual phase structures of martensite and austenite have considerable potential for industrial application in high abrasion environments due to their hardness, strength and relatively low cost. To design cost effective high carbon steels with superior properties, it is crucial to identify the effect of Chromium (Cr) on the stability of retained austenite (RA) and to fully understand its effect on solid-state phase transition. This study addresses this important knowledge gap. Using standard compression tests on bulk material, quantitative X-ray diffraction analysis, nano-indentation on individual austenitic grains, transmission electron microscopy and electron backscatter diffraction–based orientation microscopy techniques, the authors investigated the effect of Cr on the microstructure, transformation behaviour and mechanical stability of retained austenite in high carbon steel, with varying Cr contents. The results revealed that increasing the Cr %, altered the morphology of the RA and increased its stability, consequently, increasing the critical pressure for martensitic transformation. This study has critically addressed the elastoplastic behaviour of retained austenite – and provides a deep understanding of the effect of small additions of Cr on the metastable austenite of high carbon steel from the macro- to nano-level. Consequently, it paves the way for new applications for high carbon low alloy steels. - Highlights: • Effect of small addition of Cr on metastable austenite of high carbon steel from the macro- to nano-level • A multi-scale study of elastoplastic behaviour of retained austenite in high carbon steel • The mechanical stability of retained austenite during plastic deformation increased with increasing Cr content • Effect of grain boundary misorientation angle on hardness of individual retained austenite grains in high carbon steel.

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. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Corrosion Behaviour of Nickel Plated Low Carbon Steel in Tomato Fluid

Directory of Open Access Journals (Sweden)

Oluleke OLUWOLE

2010-12-01

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

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

NARCIS (Netherlands)

Tuzovskaya, I.; Pacheco Benito, Sergio; Chinthaginjala, J.K.; Reed, C.P.; Lefferts, Leonardus; van der Meer, Theodorus 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

Properties of welded joints of 2,25Cr-1Mo steel with various carbon content

International Nuclear Information System (INIS)

Vornovitskij, I.N.; Brodetskaya, E.Z.; Pozdnyakova, A.S.

1980-01-01

Properties of welded joints of 2,25 Cr - 1 Mo steel pipelines with different carbon content are considered. It is shown that application of electrodes developed in some countries for welding permits in many cases to exclude heat treatment of welded joints owing to high ductility of weld deposited metal. To improve the ductility, it is necessary to limit both carbon content down to 0,03-0,06% and detrimental elements (sulfur, phosphorus). Heat affected zone hardness may be increased at the expense of carbon. Weld deposited metal possesses the highest long-term strength at the given test temperature; in this case long-term strength of welded joints and base metal is practically the same. The long-term strength of high-carbon steel is higher at the test temperature of 565 deg C as compared to mean-carbon and low-carbon steels, whose long-term strength is practically equal at this temperature. The long-term strength of high-carbon and mean-carbon steels is practically the same and higher as compared with low-carbon one at the test temperature of 510 deg C

Surface protection of austenitic steels by carbon nanotube coatings

Science.gov (United States)

MacLucas, T.; Schütz, S.; Suarez, S.; Mücklich, F.

2018-03-01

In the present study, surface protection properties of multiwall carbon nanotubes (CNTs) deposited on polished austenitic stainless steel are evaluated. Electrophoretic deposition is used as a coating technique. Contact angle measurements reveal hydrophilic as well as hydrophobic wetting characteristics of the carbon nanotube coating depending on the additive used for the deposition. Tribological properties of carbon nanotube coatings on steel substrate are determined with a ball-on-disc tribometer. Effective lubrication can be achieved by adding magnesium nitrate as an additive due to the formation of a holding layer detaining CNTs in the contact area. Furthermore, wear track analysis reveals minimal wear on the coated substrate as well as carbon residues providing lubrication. Energy dispersive x-ray spectroscopy is used to qualitatively analyse the elemental composition of the coating and the underlying substrate. The results explain the observed wetting characteristics of each coating. Finally, merely minimal oxidation is detected on the CNT-coated substrate as opposed to the uncoated sample.

The effect of variations in carbon activity on the carburization of austenitic steels in sodium

International Nuclear Information System (INIS)

Gwyther, J.R.; Hobdell, M.R.; Hooper, A.J.

1978-07-01

Experience has shown that the liquid sodium coolant of fast breeder reactors is an effective carbon-transport medium; the resulting carburization of thin austenitic stainless steel components (eg IHX and fuel cladding) could adversely affect their mechanical integrity. The degree and nature of steel carburization depend, inter alia, on the carbon activity of the sodium environment. Exploratory tests are described in which specimens of austenitic stainless steel were carburized in sodium, the carbon activity of which was continuously monitored by a BNL electrochemical carbon meter. The sodium carbon activity was initially high, but decreased with time, simulating conditions equivalent to plant start-up or coolant clean-up following accidental oil ingress. The extent and nature of steel carburization was identified by metallography, electron microscopy, X-ray crystallography and chemical analysis. (author)

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)

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

Science.gov (United States)

2013-03-19

...] Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation of... ``ITC'') that revocation of the antidumping duty (``AD'') orders on corrosion-resistant carbon steel... (``Sunset'') Review, 77 FR 85 (January 3, 2012). \\2\\ See Corrosion-Resistant Carbon Steel Flat Products From...

intercritical heat treatments effects on low carbon steels quenched

African Journals Online (AJOL)

DR B. A. EZEKOYE

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

Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

Energy Technology Data Exchange (ETDEWEB)

Moon, Joonoh, E-mail: mjo99@kims.re.kr [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju [Sheet Products Design Team, Technical Research Center, Hyundai Steel Company, 1480 Bukbusaneop-ro, Dangjin, Chungnam 343-823 (Korea, Republic of); Lee, Chang-Hoon; Lee, Tae-Ho [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of)

2016-01-15

Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M{sub 3}C→MX→MX+M{sub 7}C{sub 3}+M{sub 23}C{sub 6}. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M{sub 3}C particle, and increased after 10 min by the precipitation of M{sub 7}C{sub 3} and M{sub 23}C{sub 6} particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M{sub 7}C{sub 3} particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M{sub 23}C{sub 6} and M{sub 7}C{sub 3} particles deteriorated the HIC resistance.

Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

International Nuclear Information System (INIS)

Moon, Joonoh; Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju; Lee, Chang-Hoon; Lee, Tae-Ho

2016-01-01

Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M_3C→MX→MX+M_7C_3+M_2_3C_6. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M_3C particle, and increased after 10 min by the precipitation of M_7C_3 and M_2_3C_6 particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M_7C_3 particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M_2_3C_6 and M_7C_3 particles deteriorated the HIC resistance.

APIs

CERN Document Server

Jacobson, Daniel; Woods, Dan

2011-01-01

Programmers used to be the only people excited about APIs, but now a growing number of companies see them as a hot new product channel. This concise guide describes the tremendous business potential of APIs, and demonstrates how you can use them to provide valuable services to clients, partners, or the public via the Internet. You'll learn all the steps necessary for building a cohesive API business strategy from experts in the trenches. Facebook and Twitter APIs continue to be extremely successful, and many other companies find that API demand greatly exceeds website traffic. This book offe

Low carbon manganese-nickel-niobium steel

International Nuclear Information System (INIS)

Heisterkamp, F.; Hulka, K.

1983-11-01

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

76 FR 66893 - Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Final...

Science.gov (United States)

2011-10-28

...] Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Final Results of... circular welded carbon steel pipes and tubes from India, Thailand, and Turkey, pursuant to section 751(c..., Thailand, and Turkey. See Antidumping Duty Order; Certain Welded Carbon Steel Standard Pipes and Tubes from...

Comparison of angular dependence of magnetic Barkhausen noise of hysteresis and initial magnetization curve in API5L steel

Science.gov (United States)

Chávez-Gonzalez, A. F.; Martínez-Ortiz, P.; Pérez-Benítez, J. A.; Espina-Hernández, J. H.; Caleyo, F.

2018-01-01

This work analyzes the differences between the magnetic Barkhausen noise corresponding to the initial magnetization curve and Barkhausen noise corresponding to one branch of the hysteresis loop in API-5L steel. The outcomes show that the Barkhausen noise signal corresponding to the initial magnetization curve and that corresponding to the hysteresis are significantly different. This difference is due to the presence of different processes of the domain wall dynamics in both phenomena. To study the processes present in magnetization dynamics for an applied field of H > 0, research into the angular dependence of a Barkhausen signal using applied field bands has revealed that a Barkhausen signal corresponding to the initial magnetization curve is more suitable than a Barkhausen signal corresponding to the hysteresis loop.

Variation of transition temperatures from upper to lower bainites in plain carbon steels

International Nuclear Information System (INIS)

Oka, M.; Okamoto, H.

1995-01-01

Experimental results and explanations for the transition temperature from upper to lower bainites in carbon steels containing from 0.20 to 1.80 wt%C were presented metallographically and kinematically. The experimental results are summarized as follows: (1) Lower bainite is not formed in steels with less than 0.35 wt%C and no transition from upper to lower bainite occurs. (2) The transition temperature of steels containing from 0.54 to 1.10 %C indicates a constant temperature of 350 C and does not depend on the carbon content. It is important to note that a transition temperature of 350 C corresponds to the Ms temperature of a 0.55%C steel being the boundary of the martensite morphology between a lath and a plate. (3) Transition temperatures of steels with more than 1.10%C decrease along the a line below about 65 C from T 0 -composition line. The bainitic transformation is essentially a kind of the martensitic one and its nucleation site is considered to be a carbon depleted zone in austenite by the thermal fluctuation of carbon atom at an isothermal holding temperature. The supercooling of about 65 C below the T 0 -composition line at the carbon range more than 1.10 wt%C is attributed to the non-chemical free energy for the displacive growth of lower bainite. (orig.)

Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates

Directory of Open Access Journals (Sweden)

Aizik F.

2012-08-01

Full Text Available In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile’s core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.

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.

High carbon microalloyed martensitic steel with ultrahigh strength-ductility

Energy Technology Data Exchange (ETDEWEB)

Qin, Shengwei; Liu, Yu; Hao, Qingguo [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Ying [School of Mechanical Engineering, Shanghai Dianji University, Shanghai 200245 (China); Chen, Nailu, E-mail: nlchen@sjtu.edu.cn [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zuo, Xunwei; Rong, Yonghua [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

2016-04-29

Based on the idea of rising the mechanical stability of retained austenite by the addition of Si in Fe-Mn based steels, an Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb was designed, then its hot rolled plate was successively tread by normalization process as pretreatment of novel quenching-partitioning-tempering (Q-P-T) process. Product of tensile and elongation (PSE) of 53.94 GPa% were obtained for this high carbon Q-P-T martensitic steel, and the PSE (40.18 GPa%) obtained by the conversion of tensile sample size using Oliver formula still is more excellent PSE than those of other microalloyed advanced high strength steels reported. The microstructural characterization reveals origin of ultrahigh PSE resulting from both the increase of considerable and dispersed carbon enriched retained austenite with relative high mechanical stability in volume fraction and the decrease of brittle twin-type martensite with the sensitivity of notch.

Effects of hydrogen on carbon steels at the Multi-Function Waste Tank Facility

International Nuclear Information System (INIS)

Carlos, W.C.

1995-01-01

Concern has been expressed that hydrogen produced by corrosion, radiolysis, and decomposition of the waste could cause embrittlement of the carbon steel waste tanks at Hanford. The concern centers on the supposition that the hydrogen evolved in many of the existing tanks might penetrate the steel wall of the tank and cause embrittlement that might lead to catastrophic failure. This document reviews literature on the effects of hydrogen on the carbon steel proposed for use in the Multi-Function Waste Tank Facility for the time periods before and during construction as well as for the operational life of the tanks. The document draws several conclusions about these effects. Molecular hydrogen is not a concern because it is not capable of entering the steel tank wall. Nascent hydrogen produced by corrosion reactions will not embrittle the steel because the mild steel used in tank construction is not hard enough to be susceptible to hydrogen stress cracking and the corrosion product hydrogen is not produced at a rate sufficient to cause either loss in tensile ductility or blistering. If the steel intended for use in the tanks is produced to current technology, fabricated in accordance with good construction practice, postweld heat treated, and operated within the operating limits defined, hydrogen will not adversely affect the carbon steel tanks during their 50-year design life. 26 refs

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.

A study on the impediment of thickness diminution of Carbon steel tube by using a applied magnetic field

International Nuclear Information System (INIS)

Kim, Jong Oh; Kim, Jong Hui; Cho, Wan Sik; Hong, Sung Min; Park, Yun Won

2001-03-01

Magnetic properties of the carbon steel tube which is used as the pipe laying of cooling water in nuclear power plant were measured to research the impediment of thickness diminution of carbon steel tube. Magnetic field distribution of carbon steel tube in the applied magnetic field was simulated by computer program. On the basis of the simulation results, Alnico 5DG and Alnico 5 were selected as the permanent magnets applicable to the carbon steel tube. Sm2Co17 magnet was used to compare the performance of permanent magnets. The experimental apparatus similar to the draining environment of cooling water in nuclear power plant was also manufactured in order to research the impediment of thickness diminution of carbon steel carbon tube

Carbon and metal-carbon implantations into tool steels for improved tribological performance

Science.gov (United States)

Hirvonen, J.-P.; Harskamp, F.; Torri, P.; Willers, H.; Fusari, A.; Gibson, N.; Haupt, J.

1997-05-01

The high-fluence implantation of carbon and dual implantations of metal-metalloid pairs into steels with different microstructures are briefly reviewed. A previously unexamined system, the implantation of Si and C into two kinds of tool steels, M3 and D2, have been studied in terms of microstructure and tribological performance. In both cases ion implantation transfers a surface into an amorphous layer. However, the tribological behavior of these two materials differs remarkably: in the case of ion-implanted M3 a reduction of wear in a steel pin is observed even at high pin loads, whereas in the case of ion-implanted D2 the beneficial effects of ion implantation were limited to the lowest pin load. The importance of an initial phase at the onset of sliding is emphasized and a number of peculiarities observed in ion-implanted M3 steel are discussed.

75 FR 77828 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Extension of Time Limit...

Science.gov (United States)

2010-12-14

...-Rolled Carbon-Quality Steel Products From Brazil: Extension of Time Limit for Final Results of...-Rolled Carbon Quality Steel Products From Brazil: Preliminary Results of Countervailing Duty... administrative review of the countervailing duty order on certain hot-rolled flat-rolled carbon- quality steel...

The anaerobic corrosion of carbon steel in concrete

International Nuclear Information System (INIS)

Naish, C.C.; Balkwill, P.H.; O'Brien, T.M.; Taylor, K.J.; Marsh, G.P.

1991-01-01

This is the final report of a 2 year programme aimed at (1) determining the rate of anaerobic corrosion of steel in concrete, (2) investigating the nature of the corrosion products formed on carbon steel embedded in cementitious material under anaerobic conditions and (3) evaluating the effect of hydrogen over-pressures on the rate of anaerobic corrosion. All experiments have been carried out at temperatures in the range 20-30 0 C, ie ambient conditions. 4 refs.; 19 figs.; 6 tabs

Modelling hydrogen permeation in a hydrogen effusion probe for monitoring corrosion of carbon steels

International Nuclear Information System (INIS)

Santiwiparat, P.; Rirksomboon, T.; Steward, F.R.; Lister, D.H.; Cook, W.G.

2015-01-01

Hydrogen accumulation inside carbon steel and stainless steel devices shaped like cylindrical cups attached to a pipe containing hydrogen gas was modelled with MATLAB software. Hydrogen transfer around the bottom of the cups (edge effect) and diffusion through the cup walls (material effect) were accounted for. The variation of hydrogen pressure with time was similar for both materials, but the hydrogen plateau pressures in stainless steel cups were significantly higher than those in carbon steel cups. The geometry of the cup also affected the plateau pressure inside the cup. (author)

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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.

Electrochemical and weight-loss study of carbon steel corrosion

International Nuclear Information System (INIS)

Thomas, V.J.; Olive, R.P.

2007-01-01

The Point Lepreau Generating Station (PLGS) will undergo an 18 month refurbishment project beginning in April, 2008. During this time, most of the carbon steel piping in the primary loop will be drained of water and dried. However, some water will remain during the shutdown due to the lack of drains in some lower points in the piping system. As a result, it is necessary to examine the effect of corrosion during the refurbishment. This study examined the effect of several variables on the corrosion rate of clean carbon steel. Specifically, the effect of oxygen in the system and the presence of chloride ions were evaluated. Corrosion rates were determined using both a weight-loss technique and electrochemical methods. The experiment was conducted at room temperature. The corrosion products from the experiment were analyzed using a Raman microscope. The results of the weight-loss measurements show that the corrosion rate of polished carbon steel is independent of both the presence of oxygen and chloride ions. The electrochemical method failed to yield meaningful results due to the lack of clearly interpretable data and the inherent subjectivity in the analysis. Lepidocricite was found to be the main corrosion product using the Raman microscope. (author)

Electrochemical corrosion behavior of carbon steel with bulk coating holidays

Institute of Scientific and Technical Information of China (English)

无

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.

Structural and tribological properties of carbon steels modified by plasma pulses

International Nuclear Information System (INIS)

Sartowska, B.; Walis, L.; Piekoszewski, J.; Senatorski, J.; Stanislawski, J.; Nowicki, L.; Ratajczak, R.; Barlak, M.; Kopcewicz, M.; Kalinowska, J.; Prokert, F.

2006-01-01

Carbon steels with different concentration of carbon and heat (Armco-iron, steels 20, 45, 65 and N9) were treated according to the standard procedures: they were irradiated with five intense (about 5 J/cm 2 ), short (μs range) argon or nitrogen plasma pulses generated in a rod plasma injector (RPI) type of plasma generator. Samples were characterized by the following methods: nuclear reaction analysis (NRA) 14 N(d,α) 12 C , scanning electron microscopy (SEM), conversion electron Moessbauer spectroscopy (CEMS), X-ray diffraction analysis (GXRD), and Amsler wear tests. SEM observations shown that the morphology of the pulse treated samples, both argon and nitrogen plasma are identical. It has been found, that nitrogen is much more efficient than argon in ausenitization of carbon steel. The craters and droplets are uniformly distributed over the surface, which is typical of melted and rapidly recrystallized top layers. The thickness of the modified layers is in the range of 1.2-1.6 μm

Carbon steel protection in G.S. [Girldler sulphide] plants: Pt. 7

International Nuclear Information System (INIS)

Lires, Osvaldo; Delfino, Cristina; Rojo, Enrique.

1989-01-01

In order to protect carbon steel towers and piping of a GS experimental heavy water plant against corrosion produced by the action of aqueous solutions of hydrogen sulphide, a method, elsewhere published, was developed. Carbon steel exposed to saturated aqueous solutions of hydrogen sulphide forms iron sulphide scales. In oxygen free solutions, evolution of corrosion follows the sequence mackinawite → cubic ferrous sulphide → troilite → pyrrotite → pyrite. Scales formed by pyrrotite and pyrite are the most protective layers (these are obtained at 130 deg C, 2 MPa for a period of 14 days). During a plant shutdown procedures, the carbon steel protected with those scales is exposed to water and highly humid air; under such conditions oxidation is unavoidable. Later, treatment in plant conditions does not regenerate scales because the composition of regenerated scales involves more soluble iron sulphides such as mackinawite and troilite. Therefore, it is not recommendable to expose the protective scales to atmospherical conditions. (Author)

Special Advanced Studies for Pollution Prevention. Delivery Order 0017: Sol-Gel Surface Preparation for Carbon Steel and Stainless Steel Bonding

National Research Council Canada - National Science Library

Zheng, Haixing

1997-01-01

The objective of this program is to study the feasibility of using sol-gel active alumina coatings for the surface preparation of carbon steel and stainless steel for adhesive bonding, and to optimize...

75 FR 64246 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of...

Science.gov (United States)

2010-10-19

...-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of Antidumping Duty Order AGENCY... certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Antidumping Duty Order: Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, 67 FR 11093 (March 12, 2002...

The Dutch xAPI Experience: xAPI Recipes

OpenAIRE

Berg, Alan; Scheffel, Maren; Drachsler, Hendrik; Ternier, Stefaan; Specht, Marcus

2017-01-01

We present the collected experiences since 2012 of the Dutch Special Interest Group (SIG) for Learning Analytics in the application of the xAPI standard and best practices around the application of xAPI in various contexts. We present three projects that apply xAPI in very different ways and publish a consistent set of xAPI recipes.

75 FR 55745 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

Science.gov (United States)

2010-09-14

... Products covered by this order are certain corrosion-resistant carbon steel flat products from Korea. These... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... review of the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE...

A discussion for stabilization time of carbon steel in atmospheric corrosion

Science.gov (United States)

Zhang, Zong-kai; Ma, Xiao-bing; Cai, Yi-kun

2017-09-01

Stabilization time is an important parameter in long-term prediction of carbon steel corrosion in atmosphere. The range of the stabilization time of carbon steel in atmospheric corrosion has been published in many scientific literatures. However, the results may not precise because engineering experiences is dominant. This paper deals with the recalculation of stabilization time based on ISO CORRAG program, and analyzes the results and makes a comparison to the data mentioned above. In addition, a new thinking to obtain stabilization time will be proposed.

Does carbonation of steel slag particles reduce their toxicity? An in vitro approach.

Science.gov (United States)

Ibouraadaten, Saloua; van den Brule, Sybille; Lison, Dominique

2015-06-01

Mineral carbonation can stabilize industrial residues and, in the steel industry, may contribute to simultaneously valorize CO2 emissions and slag. We hypothesized that, by restricting the leaching of metals of toxicological concern such as Cr and V, carbonation can suppress the toxicity of these materials. The cytotoxic activity (WST1 assay) of slag dusts collected from a stainless and a Linz-Donawitz (LD) steel plant, before and after carbonation, was examined in J774 macrophages. The release of Cr, V, Fe, Mn and Ni was measured after incubation in artificial lung fluids mimicking the extracellular and phagolysosomal milieu to which particles are confronted after inhalation. LD slag had the higher Fe, Mn and V content, and was more cytotoxic than stainless steel slag. The cytotoxic activity of LD but not of stainless dusts was reduced after carbonation. The cytotoxic activity of the dusts toward J774 macrophages necessitated a direct contact with the cells and was reduced in the presence of inhibitors of phagocytosis (cytochalasin D) or phagolysosome acidification (bafilomycin), pointing to a key role of metallic constituents released in phagolysosomes. This in vitro study supports a limited reduction of the cytotoxic activity of LD, but not of stainless, steel dusts upon carbonation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Successive carbon- and boron saturation of KhVG steel in powder mixtures

Energy Technology Data Exchange (ETDEWEB)

Alimov, Yu A; Gordienko, S I

1975-01-01

Method of successive saturation of KhVG steel with carbon and boron in powder mixtures is described. After carbonization of steel in a charcoal carburator at 930 deg C during 3 hrs a domain of equiaxial large grains is formed there the latter representing carbides of Fe/sub 3/C and (Fe, M)/sub 3/C. The increase of duration of carbonization up to 5 hrs and above results in formation of a cement grid greatly impairing the mechanical properties of the metal. Carbonization is followed by borating in powdered technical boron carbide at 900 deg C for 4 hrs which ensures formation on the sample surface of a borated layer with depth up to 65 mkm covering the carbonized zone. As followed from metallographic and x-ray structural analysis, the borated layer consists of boride needles with complex composition (Fe, Cr, Mn)B. Oil hardening of carbonized KhVG steel from 850 deg C and low-temperature tempering at 180 deg C for 1 hr results in formation in the main metal of martensite-carbide structure and, respectively, in the decrease of the microhardness gradient between the diffusion layers, as compared with borated KhVG steel. Operation tests of strengthened matrices of preforming machines under the conditions of application of dynamic pressing forces up to 1500 kg Fce/cm/sup 2/ demonstrated that the cyclical strength of carboborated coverings is 2.0-3.0 times higher than that of borated ones. The method of carboborating is recommended for strengthening the details of stamp and press tools.

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

International Nuclear Information System (INIS)

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

1998-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-06-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

OpenAIRE

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-01-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The rev...

Carbon transfer between 2 1/4 Cr 1 Mo alloy and austenitic steels (experiments in anisothermal loops)

International Nuclear Information System (INIS)

Baque, P.; Besson, M.; Champeix, L.; Donati, J.R.; Oberlin, C.; Saint-Paul, P.

1976-01-01

Studies on carbon transfer between the ferritic steel 2 1/4 Cr 1 Mo and the austenitic steels 316L and 321H have shown that there is not any measurable carbon transfer in the operating conditions of the secondary circuit of PHENIX (475 deg C was the maximal temperature of the 2 1/4 Cr 1 Mo steel). A significant carbon transfer has been observed between the ferritic steel and the 316L steel when the 321H was replaced by the 2 1/4 Cr 1 Mo steel in the same thermohydraulic conditions (the ferritic steel was then used up to 545 deg C). This experiment has demonstrated the importance of the temperature and the initial carbon content of the ferritic steel as parameters in the decarburization process. It appears that decarburization may not be sensitive to the thermohydraulic conditions at least in the range investigated in those experiments. In the other hand the 316L steel is observed to have been carburized, the degree of carburization remaining appreciably constant and independent on the temperature between 400 deg C and 550 deg C [fr

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.

Hardness and adhesion performances of nanocoating on carbon steel

Science.gov (United States)

Hasnidawani, J. N.; Azlina, H. N.; Norita, H.; Bonnia, N. N.

2018-01-01

Nanocoatings industry has been aggressive in searching for cost-effective alternatives and environmental friendly approaches to manufacture products. Nanocoatings represent an engineering solution to prevent corrosion of the structural parts of ships, insulation and pipelines industries. The adhesion and hardness properties of coating affect material properties. This paper reviews ZnO-SiO2 as nanopowder in nano coating formulation as the agent for new and improved coating performances. Carbon steel on type S50C used as common substrate in nanocoating industry. 3wt% ZnO and 2wt% SiO2 addition of nanoparticles into nanocoating showed the best formulation since hardness and adhesion of nanocoating was good on carbon steel substrate. Incorporation of nanoparticles into coating increased the performances of coating.

A computational model for the carbon transfer in stainless steel sodium systems

International Nuclear Information System (INIS)

Casadio, S.; Scibona, G.

1980-01-01

A method is proposed of computing the carbon transfer in the type 316, 304 and 321 stainless steels in sodium environment as a function of temperature, exposure time and carbon concentration in the sodium. The method is based on the criteria developed at ANL by introducing some simplifications and takes also into account the correlations obtained at WARD. Calculated carbon profiles are compared both with experimental data and with the results available by the other computer methods. The limits for quantitative predictions of the stainless steel carburization or decarburization exposed in a specific environment are discussed. (author)

The effect of cyclic and dynamic loads on carbon steel pipe

International Nuclear Information System (INIS)

Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.

1996-02-01

This report presents the results of four 152-mm (6-inch) diameter, unpressurized, circumferential through-wall-cracked, dynamic pipe experiments fabricated from STS410 carbon steel pipe manufactured in Japan. For three of these experiments, the through-wall crack was in the base metal. The displacement histories applied to these experiments were a quasi-static monotonic, dynamic monotonic, and dynamic, cyclic (R = -1) history. The through-wall crack for the third experiment was in a tungsten-inert-gas weld, fabricated in Japan, joining two lengths of STS410 pipe. The displacement history for this experiment was the same history applied to the dynamic, cyclic base metal experiment. The test temperature for each experiment was 300 C (572 F). The objective of these experiments was to compare a Japanese carbon steel pipe material with US pipe material, to ascertain whether this Japanese steel was as sensitive to dynamic and cyclic effects as US carbon steel pipe. In support of these pipe experiments, quasi-static and dynamic, tensile and fracture toughness tests were conducted. An analysis effort was performed that involved comparing experimental crack initiation and maximum moments with predictions based on available fracture prediction models, and calculating J-R curves for the pipe experiments using the η-factor method

Microstructural investigations of 0.2% carbon content steel

Science.gov (United States)

Tollabimazraehno, Sajjad; Hingerl, Kurt

2011-10-01

The effect of thermal annealing to get different phases on low carbon steel was investigated. Steel sheets (0.2 wt. % C) of 900 μm thickness were heat treated to produce different structures. All the samples have the same starting point, transformation to coarse austenite at 900 degree Celsius. The nano indentation results revealed that samples have different hadness. By making conventional SEM micrographs, focus ion beam maps, and Electron backscatter diffraction (EBSD) the microstructural development and grain boundary variation of transformed phases martensite, biainte, tempered martensite and different combination of these phases were studied.

Surface modifications induced by yttrium implantation on low manganese-carbon steel

Energy Technology Data Exchange (ETDEWEB)

Caudron, E.; Buscail, H. [Univ. Blaise Pascal Clermont-Fd II, Le Puy en Velay (France). Lab. Vellave d' Elaboration et d' Etude des Materiaux; Haanapel, V.A.C.; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Health and Consumer Protection, Joint Research Center, The European Commission, 21020, Ispra (Italy)

1999-12-15

Low manganese-carbon steel samples were ion implanted with yttrium. Sample compositions and structures were investigated before and after yttrium implantations to determine the yttrium distribution in the sample. Yttrium implantation effects were characterized using several analytical and structural techniques such as X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction, glancing angle X-ray diffraction and Rutherford backscattering spectrometry. In this paper it is shown that correlation between composition and structural analyses provides an understanding of the main compounds induced by yttrium implantation in low manganese-carbon steel. (orig.)

The difference in thermal and mechanical stabilities of austenite between carbon- and nitrogen-added metastable austenitic stainless steels

International Nuclear Information System (INIS)

Masumura, Takuro; Nakada, Nobuo; Tsuchiyama, Toshihiro; Takaki, Setsuo; Koyano, Tamotsu; Adachi, Kazuhiko

2015-01-01

In order to evaluate the effects of carbon and nitrogen addition on the stability of austenite, athermal and deformation-induced α′-martensitic transformation behaviors were investigated using type 304-metastable austenitic stainless steels containing 0.1 mass% carbon or nitrogen. The difference in the development of the deformation microstructure in particular is discussed in terms of the stacking-fault energy (SFE). Since carbon-added steel has a lower SFE than that of nitrogen-added steel, deformation twins and ε-martensite were preferentially formed in the carbon-added steel, whereas a dislocation cell structure developed in the nitrogen-added steel. Crystallographic analysis using the electron backscatter diffraction method revealed that the difference in the deformation microstructure has a significant influence on the growth behavior of deformation-induced α′-martensite, that is, the interface of the deformation twins and ε-martensite suppresses the growth of α′-martensite, whereas dislocation cell boundaries are not effective. As a result, the mechanical stability of carbon-added steel is slightly higher than that of nitrogen-added steel, although the thermal stabilization effect of carbon is much lower than that of nitrogen

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

Directory of Open Access Journals (Sweden)

Ikhlas Basheer

2015-02-01

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

Effect of artificial aging on the microstructure of weldment on API 5L X-52 steel pipe

International Nuclear Information System (INIS)

Vargas-Arista, B.; Hallen, J.M.; Albiter, A.

2007-01-01

The effects of artificial aging on the microstructure in the weldment of an API 5L X-52 steel pipe were studied. Aging was performed at 250 deg. C over a period of 1000 h and values were recorded at every 100 h intervals. Transmission electron microscopy observations showed precipitation strengthening from nearly circular Nb-C containing nanoparticles for the base metal and heat affected zone, and cementite for the weld metal. The largest amount of precipitation in the weldment zone was obtained at 500 h, due to peak-aging, which showed the highest particle density. The weld metal was more susceptible to aging, exhibiting the highest increase in precipitation at 500 h, followed by the heat affected zone. After 500 h, the deterioration in the microstructure was caused by the coarsening of particles due to over-aging. The base metal showed the larger increment in particle size after 900 h of aging accompanied by a bigger decrease in fine particles than in the weld metal

A Study of the Effect of Interrupted Quenches on a Thermomechanically Processed High Carbon Steel.

Science.gov (United States)

1982-10-01

steel . Successful martempering requires a cooling rate sufficient to avoid the nose of the C- curve and thus prevent significant bainite formation. When...STUDY OF THE EFFECT OF INTERRUPTED QUENCHES ON A THERMONECHANICALLY PROCESSED HIGH CARBON STEEL by Steven A. Barton October 1982 Thesis Advisor: T.R...unlimited. A Study of the Effect of Interrupted Quenches on a Thermomechanically Processed High Carbon Steel by Steven A. Barton Lieutenant, United

The Mechanism of High Ductility for Novel High-Carbon Quenching-Partitioning-Tempering Martensitic Steel

Science.gov (United States)

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

2015-09-01

In this article, a novel quenching-partitioning-tempering (Q-P-T) process was applied to treat Fe-0.6C-1.5Mn-1.5Si-0.6Cr-0.05Nb hot-rolled high-carbon steel and the microstructures including retained austenite fraction and the average dislocation densities in both martensite and retained austenite were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, respectively. The Q-P-T steel exhibits high strength (1950 MPa) and elongation (12.4 pct). Comparing with the steel treated by traditional quenching and tempering (Q&T) process, the mechanism of high ductility for high-carbon Q-P-T steel is revealed as follows. Much more retained austenite existing in Q-P-T steel than in Q&T one remarkably enhances the ductility by the following two effects: the dislocation absorption by retained austenite effect and the transformation-induced plasticity effect. Besides, lower dislocation density in martensite matrix produced by Q-P-T process plays an important role in the improvement of ductility. However, some thin plates of twin-type martensite embedded in dislocation-type martensite matrix in high-carbon Q-P-T steel affect the further improvement of ductility.

Mineral CO2 sequestration by steel slag carbonation

International Nuclear Information System (INIS)

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

2005-12-01

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 feedstock for mineral CO2 sequestration. These materials are cheap, available near large point sources of CO2, and tend to react relatively rapidly with CO2 due to their chemical instability. Ground steel slag was carbonated in aqueous suspensions to study its reaction mechanisms. Process variables, such as particle size, temperature, carbon dioxide pressure, and reaction time, were systematically varied, and their influence on the carbonation rate was investigated. The maximum carbonation degree reached was 74% of the Ca content in 30 min at 19 bar pressure, 100C, and a particle size of <38 μm. The two must important factors determining the reaction rare are particle size (<2 mm to <38 μm) and reaction temperature (25-225C). The carbonation reaction was found to occur in two steps: (1) leaching of calcium from the steel slag particles into the solution; (2) precipitation of calcite on the surface of these particles. The first step and, more in particular, the diffusion of calcium through the solid matrix toward the surface appeared to be the rate-determining reaction step, The Ca diffusion was found to be hindered by the formation of a CaCO3-coating and a Ca-depleted silicate zona during the carbonation process. Research on further enhancement of the reaction rate, which would contribute to the development of a cost-effective CO2-sequestration process, should focus particularly on this mechanism

Electrochemical formation of carbonated corrosion products on carbon steel in deaerated solutions

International Nuclear Information System (INIS)

Refait, Ph.; Bourdoiseau, J.A.; Jeannin, M.; Nguyen, D.D.

2012-01-01

Highlights: ► Green rust is electro-generated at low NaHCO 3 concentration (0.003 mol dm −3 ). ► Chukanovite and carbonated green rust are obtained in NaHCO 3 + Na 2 SO 4 deaerated electrolytes. ► The mechanisms of formation of carbonated corrosion products of carbon steel are specified. - Abstract: To investigate the nature and properties of carbonated rust layers, carbon steel electrodes were polarised anodically at a potential ∼100–200 mV higher than the open circuit potential in NaHCO 3 solutions (0.003, 0.1 and 1 mol dm −3 ) continuously deaerated by an argon flow. X-ray diffraction and μ-Raman spectroscopy were used to identify the electro-generated compounds. GR(CO 3 2− ) (=Fe II 4 Fe III 2 (OH) 12 CO 3 ·4H 2 O) is observed at 0.003 and 0.1 mol dm −3 NaHCO 3 whereas FeCO 3 is obtained at the largest concentration (1 mol dm −3 ). GR(CO 3 2− ) is accompanied by magnetite Fe 3 O 4 at the lowest NaHCO 3 concentration. The current density decreases to negligible values in each case, indicating that a passive film also forms independently of the nature of the carbonated compound. Experiments were performed similarly in solutions of NaHCO 3 and Na 2 SO 4 . Chukanovite Fe 2 (OH) 2 CO 3 could be obtained in solutions containing 0.03 mol dm −3 of each salt. In contrast with the results obtained in the solutions free of sulphate, the current density remains important during the formation of the rust layer

The Effects of Cr and Al Addition on Transformation and Properties in Low‐Carbon Bainitic Steels

OpenAIRE

Junyu Tian; Guang Xu; Mingxing Zhou; Haijiang Hu; Xiangliang Wan

2017-01-01

Three low‐carbon bainitic steels were designed to investigate the effects of Cr and Al addition on bainitic transformation, microstructures, and properties by metallographic method and dilatometry. The results show that compared with the base steel without Cr and Al addition, only Cr addition is effective for improving the strength of low‐carbon bainitic steel by increasing the amount of bainite. However, compared with the base steel, combined addition of Cr and Al has no significant effect o...

Molecular carbon nitride ion beams for enhanced corrosion resistance of stainless steel

Science.gov (United States)

Markwitz, A.; Kennedy, J.

2017-10-01

A novel approach is presented for molecular carbon nitride beams to coat stainless surfaces steel using conventional safe feeder gases and electrically conductive sputter targets for surface engineering with ion implantation technology. GNS Science's Penning type ion sources take advantage of the breaking up of ion species in the plasma to assemble novel combinations of ion species. To test this phenomenon for carbon nitride, mixtures of gases and sputter targets were used to probe for CN+ ions for simultaneous implantation into stainless steel. Results from mass analysed ion beams show that CN+ and a variety of other ion species such as CNH+ can be produced successfully. Preliminary measurements show that the corrosion resistance of stainless steel surfaces increased sharply when implanting CN+ at 30 keV compared to reference samples, which is interesting from an application point of view in which improved corrosion resistance, surface engineering and short processing time of stainless steel is required. The results are also interesting for novel research in carbon-based mesoporous materials for energy storage applications and as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost.

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

76 FR 64312 - Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan: Final Results of the Expedited...

Science.gov (United States)

2011-10-18

... Rectangular Carbon Steel Tubing From Taiwan: Final Results of the Expedited Sunset Review of the Antidumping... the antidumping duty order on light-walled welded rectangular carbon steel tubing from Taiwan pursuant... steel tubing from Taiwan pursuant to section 751(c) of the Act. See Initiation of Five-Year (``Sunset...

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.

78 FR 55241 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

Science.gov (United States)

2013-09-10

... merchandise covered by this Order \\2\\ is certain corrosion- resistant carbon steel flat products from Korea... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE) from the...

Nonmetallic inclusions in carbon steel smelted in plasma furnace

Energy Technology Data Exchange (ETDEWEB)

Shengelaya, I B; Kostyakov, V N; Nodiy, T K; Imerlishvili, V G; Gavisiani, A G [AN Gruzinskoj SSR, Tbilisi. Inst. Metallurgii

1979-01-01

A complex investigation on nonmetallic inclusions in carbon cast iron, smelted in plasma furnace in argon atmosphere and cast partly in the air and partly in argon atmosphere, has been carried out. As compared to open-hearth furnace carbon steel, the test metal was found to contain more oxide inclusions and nitrides; besides, in chromium-containing metal, chromium nitrides form the larger part of nitrides.

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.

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)

Effect of Biodiesel Concentration on Corrosion of Carbon Steel by Serratia marcescens

Directory of Open Access Journals (Sweden)

Pusparizkita Yustina M

2018-01-01

Full Text Available Biodiesel come into being used as an alternative source of energy as the diminishing of petroleum reserves. This fuel is typically stored in tanks that are commonly made from carbon steel, which is easily corroded by microorganisms. Recent studies have shown that bacteria aside from SRB may also be involved in corrosion. Therefore, this research was aimed to evaluate the effect of biodiesel concentration (15%, 20% and 30% v/v mixed in diesel oil on the corrosion of carbon steel by S. marcescens that dominate biocorrosion on hydrocarbon products. In this study, the corrosion process was investigated by evaluation of biofilm morphology and composition, the rate of corrosion and the corrosion product of carbon steel which was exposed in the mixture of hydrocarbons and the presence of S. marcescens. It can be concluded that higher concentration of biodiesel in diesel oil leads to higher growth of bacteria in the biofilm and higher corrosion rate.

Testing of methods for decontamination of stainless steels and carbon steels conformably to demountable equipment of nuclear power plant with WWR type reactor

International Nuclear Information System (INIS)

Dergunova, G.M.; Nazarov, V.K.; Ozolin, A.B.; Smirnov, L.M.; Stel'mashuk, V.P.; Yulikov, E.I.; Vlasov, I.N.

1978-01-01

Results are given of experiments on decontamination of stainless steel by the oxidation-reduction method and also results of decontamination of carbon steel by means of solutions based on oxalic acid, citric acid and phosphoric acid. Investigations of efficiency of oxidation-reduction treatment were done on samples of stainless steel cut from the pipeline of the primary coolant circuit of reactor. Comparison is given of efficiency of oxidation-reduction methods of contamination of stainless steel in the case of application of different compositions of decontaminating solutions. Dependences are given for decontamination completeness on duration of operations, on temperature and on ratio of volume of decontaminating solutions to surface are of the sample. For carbon steels parameters are given for decontamination process by means of oxalic, citric and phosphoric acid solutions. (I.T.) [ru

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

Science.gov (United States)

2013-03-29

.... Scope of the Order Products covered by this order are certain corrosion-resistant carbon steel flat... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... countervailing duty (CVD) order on corrosion-resistant carbon steel flat products from the Republic of Korea for...

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.

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

International Nuclear Information System (INIS)

Torisaka, Yasunori; Kihara, Junji

1978-01-01

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

Analysis of corrosion products of carbon steel in wet bentonite

International Nuclear Information System (INIS)

Osada, Kazuo; Nagano, Tetsushi; Nakayama, Shinichi; Muraoka, Susumu

1992-02-01

As a part of evaluation of the long-term durability for the overpack containers for high-level radioactive waste, we have conducted corrosion tests for carbon steel in wet bentonite, a candidate buffer material. The corrosion rates were evaluated by weight difference of carbon steel and corrosion products were analyzed by Fourier transform infrared spectroscopy (FT-IR) and colorimetry. At 40degC, the corrosion rate of carbon steel in wet bentonite was smaller than that in pure water. At 95degC, however, the corrosion rate in wet bentonite was much higher than that in pure water. This high corrosion rate in wet bentonite at 95degC was considered to result from evaporation of moisture in bentonite in contact with the metal. This evaporation led to dryness and then to shrinkage of the bentonite, which generated ununiform contact of the metal with bentonite. Probably, this ununiform contact promoted the local corrosion. The locally corroded parts of specimen in wet bentonite at 95degC were analyzed by Fourier transform infrared microspectroscopy (micro-FT-IR), and lepidocrocite γ-FeO(OH) was found as well as goethite α-FeO(OH). In wet bentonite at 95degC, hematite α-Fe 2 O 3 was identified by means of colorimetry. (author)

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.

Microbiologically influenced corrosion of carbon steel in the presence of sulphate reducing bacteria

International Nuclear Information System (INIS)

Tunaru, M.; Velciu, L.; Mihalache, M.; Laurentiu, P.

2016-01-01

Sulphate-reducing bacteria (SRB) are the most important organisms in microbiologically induced corrosion. In this context, the paper presents an assessment (by experimental tests) of the behaviour of carbon steel samples (SA106gr.B) in SRB media. Some of samples were immersed in microbial environment in order microbiological analysis of their surface and another part was used to perform accelerated electrochemical tests to determine electrochemical parameters for the system carbon steel / microbial medium (corrosion rate, the polarization resistance of the surface, susceptibility to pitting corrosion). The surfaces of the tested samples were analyzed using the optical and electronic microscope, and emphasized the role of bacteria in the development of biofilms under which appeared characteristics of corrosion attack. The correlation of all results confirmed that SRB accelerated the localized corrosion of the surfaces of SA 106gr.B carbon steel. (authors)

Influences of spray parameters on the structure and corrosion resistance of stainless steel layers coated on carbon steel by plasma spray treatment

International Nuclear Information System (INIS)

Yeom, Kyong An; Lee, Sang Dong; Kwon, Hyuk Sang; Shur, Dong Soo; Kim, Joung Soo

1996-01-01

Stainless steel powders were sprayed on the grit-blasted SM45C carbon steel substrates using a plasma spray method. The influences of the spray parameters on the structure and corrosion resistance of the layers coated on the carbon steel were investigated. Corrosion behavior of the layers were analyzed by the anodic polarization tests in deaerated 0.1 M NaCl + 0.01 M NaOH solution at 80 deg C. The surface roughness and porosity were observed to decrease with decreasing the particle size. The surface hardness of the coating was always higher than that of the matrix, SM45C, implying that the higher resistance of the coating to erosion-corrosion than that of matrix, and increased as the spray power and the spray distance increase. Stainless steel coats showed more corrosion resistance than the carbon steel did, due to their passivity. The corrosion resistance of the coats, however, were inferior to that of the bulk stainless steels due to the inherent defects formed in the coats. The defects such as rough surface and pores provided the occluded sites favorable for the initiation of localized corrosion, resulting in the conclusion that finer the powder is, higher the corrosion resistance is. And the Cr oxides formation resulting in Cr depletion around the oxides reduced the corrosion resistance of the coats. (author)

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.

Influence of ultraviolet light irradiation on the corrosion behavior of carbon steel AISI 1015

Science.gov (United States)

Riazi, H. R.; Danaee, I.; Peykari, M.

2013-03-01

Corrosion of carbon steel in sodium chloride solution was studied under ultraviolet illumination using weight loss, polarization, electrochemical impedance spectroscopy and current transient tests. The polarization test revealed an increase in the corrosion current density observed under UV illumination. The impedance spectroscopy indicated that the charge transfer resistance of the system was decreased by irradiation of UV light on a carbon steel electrode. The weight loss of carbon steel in solution increased under UV light, which confirms the results obtained from electrochemical measurements. We propose that the main effect of UV irradiation is on the oxide film, which forms on the surface. Thus, in presence of UV, the conductivity of oxide film might increase and lead to higher metal dissolution and corrosion rate.

75 FR 32160 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Extension of Time Limit...

Science.gov (United States)

2010-06-07

...-Rolled Carbon-Quality Steel Products from Brazil: Extension of Time Limit for Preliminary Results of...-quality steel products from Brazil. See Agreement Suspending the Countervailing Duty Investigation on Hot... duty order on certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Initiation...

75 FR 29976 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Extension of the Final...

Science.gov (United States)

2010-05-28

... DEPARTMENT OF COMMERCE International Trade Administration [A-475-826] Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Extension of the Final Results of Antidumping Duty Administrative...-quality steel plate products from Italy. See Certain Cut-to-Length Carbon-Quality Steel Plate Products...

78 FR 4385 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Preliminary...

Science.gov (United States)

2013-01-22

...-Quality Steel Plate Products From the Republic of Korea: Preliminary Results of Antidumping Duty... the antidumping duty order on certain cut-to- length carbon-quality steel plate products (CTL plate... Carbon-Quality Steel Plate Products from the Republic of Korea'' dated concurrently with this notice...

Cast Steel Filtration Trials Using Ceramic-Carbon Filters

Directory of Open Access Journals (Sweden)

Lipowska B.

2014-12-01

Full Text Available Trials of cast steel filtration using two types of newly-developed foam filters in which carbon was the phase binding ceramic particles have been conducted. In one of the filters the source of carbon was flake graphite and coal-tar pitch, while in the other one graphite was replaced by a cheaper carbon precursor. The newly-developed filters are fired at 1000°C, i.e. at a much lower temperature than the currently applied ZrO2-based filters. During filtration trials the filters were subjected to the attack of a flowing metal stream having a temperature of 1650°C for 30 seconds.

Corrosion of a carbon steel in simulated liquid nuclear wastes

International Nuclear Information System (INIS)

Saenz Gonzalez, Eduardo

2005-01-01

This work is part of a collaboration agreement between CNEA (National Atomic Energy Commission of Argentina) and USDOE (Department of Energy of the United States of America), entitled 'Tank Corrosion Chemistry Cooperation', to study the corrosion behavior of carbon steel A537 class 1 in different simulated non-radioactive wastes in order to establish the safety concentration limits of the tank waste chemistry at Hanford site (Richland-US). Liquid high level nuclear wastes are stored in tanks made of carbon steel A537 (ASTM nomenclature) that were designed for a service life of 20 to 50 years. A thickness reduction of some tank walls, due to corrosion processes, was detected at Hanford site, beyond the existing predicted values. Two year long-term immersion tests were started using non radioactive simulated liquid nuclear waste solutions at 40 C degrees. This work extends throughout the first year of immersion. The simulated solutions consist basically in combinations of the 10 most corrosion significant chemical components: 5 main components (NaNO 3 , NaCl, NaF, NaNO 2 and NaOH) at three concentration levels and 5 secondary components at two concentration levels. Measurements of the general corrosion rate with time were performed for carbon steel coupons, both immersed in the solutions and in the vapor phases, using weight loss and electrochemistry impedance spectroscopy techniques. Optic and scanning electron microscopy examination, analysis of U-bend samples and corrosion potential measurements, were also done. Localized corrosion susceptibility (pitting and crevice corrosion) was assessed in isolated short-term tests by means of cyclic potentiodynamic polarization curves. The effect of the simulated waste composition on the corrosion behavior of A537 steel was studied based on statistical analyses. The Surface Response Model could be successfully applied to the statistical analysis of the A537 steel corrosion in the studied solutions. General corrosion was not

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

International Nuclear Information System (INIS)

Lee, Hyo Bok

1979-01-01

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

Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

Energy Technology Data Exchange (ETDEWEB)

Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun [Pusan National University, School of Mechanical Engineering, Busan (Korea, Republic of)

2010-10-15

The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

International Nuclear Information System (INIS)

Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun

2010-01-01

The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

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

International Nuclear Information System (INIS)

Stumpf, Waldo; Banks, Kevin

2006-01-01

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

An Evaluation of Carbon Steel Corrosion Under Stagnant Seawater Conditions

National Research Council Canada - National Science Library

Lee, Jason

2004-01-01

Corrosion, of 1020 carbon steel coupons in, natural seawater over a six-month period was more aggressive under stagnant anaerobic conditions than stagnant aerobic conditions as measured by weight loss...

Microstructure and Mechanical Properties of Austempered Medium-Carbon Spring Steel

Science.gov (United States)

Kim, Seong Hoon; Kim, Kwan-Ho; Bae, Chul-Min; Lee, Jae Sang; Suh, Dong-Woo

2018-03-01

Changes in microstructure and mechanical properties of medium-carbon spring steel during austempering were investigated. After austempering for 1 h at 290 °C or 330 °C, the bainite transformation stabilized austenite, and microstructure consisting of bainitic ferrite and austenite could be obtained after final cooling; the retained austenite fraction was smaller in the alloy austempered at 290 °C because carbon redistribution between bainitic ferrite and austenite slowed as the temperature decreased, and thereby gave persistent driving force for the bainite transformation. The products of tensile strength and reduction of area in the austempered alloy were much larger in the austempered steel than in quenched and tempered alloy, mainly because of significant increase in reduction of area in austempered alloy.

Effect of nanoprecipitates and grain size on the mechanical properties of advanced structural steels

International Nuclear Information System (INIS)

Suarez, M.A.; Alvarez-Perez, M.A.; Alvarez-Fregoso, O.; Juarez-Islas, J.A.

2011-01-01

Highlights: → The composition of the steel responded positively to the thermomechanical processing. → Yield strength was increased due to micrometric grain size of 2.2 μm. → Mechanical properties were improved due to nanometric precipitates of 5 nm. → Yield strength values of the API steel were improved up to 877.9 MPa. - Abstract: The microstructure and nanometric precipitates present in advanced structured steel have been studied by high resolution transmission electron microscopy equipped with energy dispersion X-ray microanalysis, in order to relate the nanometric precipitates and grain size with the improvement of the yield strength value of the API steel. The microstructure and nanometric precipitates of the advanced steel were obtained by a combination of thermo-mechanical controlled hot rolling and accelerated cooling procedures. The API steel composition consisted of hot rolled Nb-Ti microalloyed with: 0.07C, 1.40Mn, 0.24Si, 0.020Al, 0.009P, 0.001S, 0.05Mo, 0.5Cr, 0.05Nb, 0.25Ni, 0.10Cu, 0.012Ti, 0.05N in wt%. As a result, this hot rolled steel tested at a strain rate of 5 x 10 -3 s -1 showed an improved yield strength from 798 MPa to 878 MPa due to the micrometric grain size of 2.2 μm and to the nanometric precipitates with a size of around 5 nm in the microstructure of the steel studied.

A Study of Submicron Grain Boundary Precipitates in Ultralow Carbon 316LN Steels

Science.gov (United States)

Downey, S.; Han, K.; Kalu, P. N.; Yang, K.; Du, Z. M.

2010-04-01

This article reports our efforts in characterization of an ultralow carbon 316LN-type stainless steel. The carbon content in the material is one-third that in a conventional 316LN, which further inhibits the formation of grain boundary carbides and therefore sensitizations. Our primary effort is focused on characterization of submicron size precipitates in the materials with the electron backscatter diffraction (EBSD) technique complemented by Auger electron spectroscopy (AES). Thermodynamic calculations suggested that several precipitates, such as M23C6, Chi, Sigma, and Cr2N, can form in a low carbon 316LN. In the steels heat treated at 973 K (700 °C) for 100 hours, a combination of EBSD and AES conclusively identified the grain boundary precipitates (≥100 nm) as Cr2N, which has a hexagonal closed-packed crystallographic structure. Increases of the nitrogen content promote formation of large size Cr2N precipitates. Therefore, prolonged heat treatment at relatively high temperatures of ultralow carbon 316LN steels may result in a sensitization.

78 FR 29113 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Final...

Science.gov (United States)

2013-05-17

...-Quality Steel Plate Products From the Republic of Korea: Final Results of Antidumping Duty Administrative... administrative review of the antidumping duty order on certain cut-to-length carbon-quality steel plate products... duty order on certain cut-to-length carbon-quality steel plate products from the Republic of Korea...

CO2 laser cladding of VERSAlloyTM on carbon steel with powder feeding

International Nuclear Information System (INIS)

Kim, Jae-Do; Kweon, Jin-Wook

2007-01-01

Laser cladding processing with metal powder feeding has been experimented on carbon steel with VERSAlloy TM . A special device for the metal powder feeding was designed and manufactured. By adopting proper cladding parameters, good clad layers and sound metallurgical bonding with the base metal were obtained. Analysis indicates that the micro hardness of clad layer and the heat-affected zone increased with increasing of cladding speed. The experimental results showed that VERSAlloy TM cladded well with carbon steel

Effect of the dendritic morphology on hot tearing of carbon steels

International Nuclear Information System (INIS)

Ridolfi, M R

2016-01-01

Hot tears form during solidification in the brittle region of the dendritic front. Most hot tearing criteria are based on solid and fluid mechanics, being the phenomenon strictly depending on the solid resistance to applied strains and on the liquid capability of filling the void spaces. Modelling both mechanisms implies the precise description of the dendritic morphology. To this scope, the theory of coalescence of the dendritic arms at grain boundaries of Rappaz et al. has been applied, in this work, to the columnar growth of carbon steels by means of a simple mathematical model. Depending on the alloy composition, solid bridging starts at solid fractions down to about 0.8 and up to above 0.995 (very low carbon). The morphology of the brittle region changes drastically with increasing carbon and adding other solutes. In particular, ferritic dendrites, typical of low carbon steels, tend to offer short and wide interdendritic spaces to the surrounding liquid making possible their complete filling, and few solid bridges; peritectic steels show the rise of austenite growing and bridging rapidly in the interdendritic spaces, preventing void formation; austenitic dendrites form long and narrow interdendritic spaces difficult to reach for the liquid and with a lot of solid bridges. Sulphur addition mainly acts in delaying the coalescence end, more markedly in ferritic dendrites. (paper)

77 FR 27438 - Certain Corrosion-Resistant Carbon Steel Flat Products From Korea: Final Results of Expedited...

Science.gov (United States)

2012-05-10

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Certain Corrosion-Resistant... order on certain corrosion-resistant carbon steel flat products (``CORE'') from the Republic of Korea.... Scope of the Order The merchandise covered by the order includes flat-rolled carbon steel products, of...

Study of sulphate-reducing bacteria corrosion in the weld joint for API X-70 steel

Directory of Open Access Journals (Sweden)

Flores, J. E.

2012-10-01

Full Text Available The corrosion behavior originated by sulfate-reducing bacteria (SRB was studied in two regions of welded API X-70 steel pipeline. The studies were focused on base material (BM and heat affected zone (HAZ, from the internal region of the pipe. SRB were extracted from oil and grown in a Postgate medium. Corrosion was evaluated at 60 °C for times between 5 and 64 days. Potentiodynamic polarization curves, obtained by electrochemical techniques, indicated surface activation at short times. Structural and morphological characterizations were carried out by scanning electron microscopy (SEM and optical microscopy (OM. H₂S concentration and pH were also measured. Results showed an important increase in the corrosion damage up to 20 days, influenced by the SRB activity, which lead to a maximum of H₂S (pH minimum. It was found a localized corrosion attack in the HAZ in a higher quantity compared to BM; and the formation of a thin film on the steel surface, originated by corrosion products and bacterial activity.

El comportamiento ante la corrosión, originada por bacterias sulfato-reductoras (SRB, fue estudiado en dos regiones de un tubo de acero soldado API X-70. Los estudios se enfocaron en el material base (BM y la zona afectada térmicamente (HAZ, en la parte interna del tubo. Las SRB fueron extraídas del petróleo y cultivadas en un medio Postgate. El comportamiento a la corrosión fue evaluado a una temperatura de 60 °C, por periodos comprendidos entre 5 y 64 días. El análisis de las curvas de polarización potenciodinámicas, obtenidas por técnicas electroquímicas, indicó la activación de la superficie para tiempos cortos. La superficie fue caracterizada estructural y morfológicamente mediante microscopia electrónica de barrido (SEM, así como mediante microscopía óptica (OM. La concentración de H₂S y el pH también fueron medidos. Los resultados mostraron un aumento importante de la corrosi

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)

Grain Refinement of Low Carbon Martensitic Steel by Heat Treatment

Directory of Open Access Journals (Sweden)

N. V. Kolebina

2015-01-01

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

X-ray photoelectron spectroscopy characterization of high dose carbon-implanted steel and titanium alloys

Science.gov (United States)

Viviente, J. L.; García, A.; Alonso, F.; Braceras, I.; Oñate, J. I.

1999-04-01

A study has been made of the depth dependence of the atomic fraction and chemical bonding states of AISI 440C martensitic stainless steel and Ti-6Al-4V alloy implanted with 75 keV C + at very high doses (above 10 18 ions cm -2), by means of X-ray photoelectron spectroscopy combined with an Ar + sputtering. A Gaussian-like carbon distribution was observed on both materials at the lowest implanted dose. More trapezoidal carbon depth-profiles were found with increasing implanted doses, and a pure carbon layer was observed only on the titanium alloy implanted at the highest dose. The implanted carbon was combined with both base metal and carbon itself to form metallic carbides and graphitic carbon. Furthermore, carbon-enriched carbides were also found by curve fitting the C 1s spectra. The titanium alloy showed a higher carbidic contribution than the steel implanted at the same C + doses. A critical carbon concentrations of about 33 at.% and 23 at.% were measured for the formation of C-C bonds in Ti-6Al-4V and steel samples, respectively. The carbon atoms were bound with metal to form carbidic compounds until these critical concentrations were reached; when this C concentration was exceeded the proportion of C-C bonds increased and resulted in the growth of carbonaceous layers.

Formation of low friction and wear-resistant carbon coatings on tool steel by 75keV, high-dose carbon ion implantation

International Nuclear Information System (INIS)

Mikkelsen, N.J.; Eskildsen, S.S.; Straede, C.A.; Chechenin, N.G.

1994-01-01

Hardened AISI D2 steel samples were subjected to mass-separated C + ion bombardment at 75keV with ion doses in the range 0.5-15x10 18 C + cm -2 . It was observed that sputtering was still limited, and the system exhibited internal growth, because most of the ions penetrated more than 0.1μm into the growing carbon film. At the lowest ion doses applied, carbon was implanted into the steel, while higher doses resulted in the implanted carbon concentration near the surface being almost 100%. For the highest doses applied, Rutherford backscattering spectrometry and surface profilometry analyses showed that layers about 0.5-1μm thick of almost pure carbon grew outward from the steel substrate. Transmission electron microscopy showed that the carbon layers were amorphous and exhibited an intermixed layer-substrate interface. The layers were hard and exhibited pronounced elastic recovery when subjected to ultralow load indentation. Low friction and excellent wear properties were measured when tested under dry conditions with a ball-on-disc tribometer. ((orig.))

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

Science.gov (United States)

2012-02-02

... Rectangular Carbon Steel Tubing From Taiwan: Continuation of Antidumping Duty Order AGENCY: Import... revocation of the antidumping duty order on light-walled welded rectangular carbon steel tubing from Taiwan would likely lead to a continuation or recurrence of dumping and material injury to an industry in the...

Monitoring of stainless-steel slag carbonation using X-ray computed microtomography.

Science.gov (United States)

Boone, Marijn A; Nielsen, Peter; De Kock, Tim; Boone, Matthieu N; Quaghebeur, Mieke; Cnudde, Veerle

2014-01-01

Steel production is one of the largest contributors to industrial CO2 emissions. This industry also generates large amounts of solid byproducts, such as slag and sludge. In this study, fine grained stainless-steel slag (SSS) is valorized to produce compacts with high compressive strength without the use of a hydraulic binder. This carbonation process is investigated on a pore-scale level to identify how the mineral phases in the SSS react with CO2, where carbonates are formed, and what the impact of these changes is on the pore network of the carbonated SSS compact. In addition to conventional research techniques, high-resolution X-ray computed tomography (HRXCT) is applied to visualize and quantify the changes in situ during the carbonation process. The results show that carbonates mainly precipitate at grain contacts and in capillary pores and this precipitation has little effect on the connectivity of the pore space. This paper also demonstrates the use of a custom-designed polymer reaction cell that allows in situ HRXCT analysis of the carbonation process. This shows the distribution and influence of water and CO2 in the pore network on the carbonate precipitation and, thus, the influence on the compressive strength development of the waste material.

Corrosion behavior of carbon steel for overpack in groundwater containing bicarbonate ions

International Nuclear Information System (INIS)

Nishimura, Toshiyasu; Dong, Junpha

2009-01-01

Carbon steel is considered in Japan the candidate material for overpacks in high-level radioactive waste disposal. Effects of bicarbonate solutions on the corrosion behavior and corrosion products of carbon steel were investigated by electrochemical measurements, FT-IR and XRD analyses. The anodic polarization measurements showed that bicarbonate ions (HCO 3 - ) accelerated the anodic dissolution and the outer layer film formation of carbon steel in the case of high concentrations, on the other hand, it inhibited these processes in the case of low concentrations. The FT-IR and XRD analyses of the anodized film showed that siderite (FeCO 3 ) was formed in 0.5 to 1.0 mol/L bicarbonate solution, and Fe 2 (OH) 2 CO 3 in 0.1 to 0.2 mol/L bicarbonate solution, while Fe 6 (OH) 12 CO 3 was formed in 0.02 to 0.05 mol/L bicarbonate solutions. The stability of these corrosion products was able to be explained by using the actual potential-pH diagrams for the Fe-H 2 O-CO 2 system. (author)

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.

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 are to be ex...

Effect of quenching and tempering process on sulfide stress cracking susceptibility in API-5CT-C110 casing steel

Energy Technology Data Exchange (ETDEWEB)

Liu, M.; Wang, C.H.; Dai, Y.C.; Li, X.; Cao, G.H. [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Russell, A.M. [Division of Materials Science and Engineering, Ames Laboratory of the U.S.D.O.E., and Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Liu, Y.H.; Dong, X.M. [Tube & Pipe Department, Baosteel Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900 (China); Zhang, Z.H., E-mail: zhzhang@baosteel.com [Tube & Pipe Department, Baosteel Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900 (China)

2017-03-14

Three quenching and tempering processes performed on API-5CT-C110 casing steel produced tempered martensite structures and similar mechanical properties but distinct sulfide stress cracking (SSC) behavior as evaluated by Double Cantilever Beam (DCB) testing. An as-quenched specimen tempered at 690 °C for two hours showed superior SSC behavior compared to another specimen tempered at 715 °C for one hour. The latter contained a larger fraction of low-angle boundaries (LABs) and higher values of kernel average misorientation (KAM) than those in the former. Moreover, one more quenching and tempering on the former specimen would produce better SSC resistance with a decrease in the fraction of LABs and the values of KAM. Since dislocations trap hydrogen more strongly than grain boundaries, the specimen with higher KAM values, as well as higher dislocation density, would trap more hydrogen atoms and lead to greater SSC.

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

Science.gov (United States)

Song, Weimin; Yin, Jian

2016-08-18

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.

FP corrosion dependence on carbon and chromium content in Fe-Cr steel

International Nuclear Information System (INIS)

Sasaki, Koei; Tanigaki, Takanori; Fukumoto, Ken-ichi; Uno, Masayoshi

2015-01-01

In an attempt to investigate Cs or Cs-Te corrosion dependence on chromium or carbon content in Fe-Cr steel, cesium and Cs-Te corrosion test were performed to three specimens, Fe-9Cr-0C, Fe-9Cr-0.14C and Fe-13Cr-0.14C, for 100 hours at 973K in simulated high burn-up fuel pin environment. Cesium corrosion depth has no dependence on chromium or carbon content in Fe-Cr steel. Cs-Te corrosion was appeared in only Fe-13Cr-0.14C which has chromium carbides ranged along grain boundary. Appearance of the Cs-Te corrosion was determined by distribution or arrangement of chromium carbides which depends on chromium and carbon content. (author)

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

International Nuclear Information System (INIS)

Kouli, M.-E.; Giannakis, M

2016-01-01

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

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.

Development of carbon steel with superior resistance to wall thinning and fracture for nuclear piping system

International Nuclear Information System (INIS)

Rhee, Chang Kyu; Lee, Min Ku; Park, Jin Ju

2010-07-01

Carbon steel is usually used for piping for secondary coolant system in nuclear power plant because of low cost and good machinability. However, it is generally reported that carbon steel was failed catastrophically because of its low resistance to wall thinning and fracture toughness. Especially, flow accelerated corrosion (FAC) is one of main problems of the wall thinning of piping in the nuclear power plant. Therefore, in this project, fabrication technology of new advanced carbon steel materials modified by dispersion of nano-carbide ceramics into the matrix is developed first in order to improve the resistance to wall thinning and fracture toughness drastically compared to the conventional one. In order to get highly wettable fine TiC ceramic particles into molten metal, the micro-sized TiC particles were first mechanically milled by Fe (MMed TiC/Fe) in a high energy ball mill machine in Ar gas atmosphere, and then mixed with surfactant metal elements (Sn, Cr, Ni) to obtain better wettability, as this lowered surface tension of the carbon steel melt. According to microscopic images revealed that an addition of MMed TiC/Fe-surfactant mixed powders favorably disperses the fine TiC particles in the carbon steel matrix. It was also found that the grain size refinement of the cast matrix is achieved remarkably when fine TiC particles were added due to the fact that they act as nucleation sites during the solidification process. As a results, a cast carbon steel dispersed with fine TiC particles shows improved mechanical properties such as hardness, tensile strength and cavitation resistance compared to that of without particles. However, the slight decrease of toughness was found

Influence of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in bicarbonate/carbonate buffer solution

Energy Technology Data Exchange (ETDEWEB)

Li, D.G. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Tubular Goods Research Center of CNPC, Xi' an 710065 (China)], E-mail: dangguoli78@yahoo.com.cn; Feng, Y.R.; Bai, Z.Q. [Tubular Goods Research Center of CNPC, Xi' an 710065 (China); Zhu, J.W.; Zheng, M.S. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2007-11-01

The influences of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in NaHCO{sub 3}/Na{sub 2}CO{sub 3} buffer solution are investigated by capacitance measurement and electrochemical impedance spectroscopy (EIS). The results show that the passive film appears n-type semiconductive character; with increasing the solution temperature, the addition of chromium into carbon steel and increasing the concentration of chloride ions, the slopes of Mott-Schottky plots decrease, which indicates the increment of the defect density in the passive film. EIS results show that the transfer impedance R{sub 1} and the diffusion impedance W decrease with increasing the solution temperature, with the addition of chromium into carbon steel and with increasing the chloride ions concentration. It can be concluded that the corrosion protection effect of passive film on the substrate decreases with increasing the solution temperature, adding chromium into carbon steel and increasing chloride ions concentration.

corrosion response of low carbon steel in tropical road mud

African Journals Online (AJOL)

Dr Obe

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

Metallurgical study of low-temperature plasma carbon diffusion treatments for stainless steels

International Nuclear Information System (INIS)

Lewis, D.B.; Leyland, A.; Stevenson, P.R.; Cawley, J.; Matthews, A.

1993-01-01

We recently reported a novel low-temperature carbon diffusion technique for surface hardening of stainless steels. The treatment was shown to provide benefits in terms of abrasive wear resistance. There is also evidence to suggest that by performing diffusion treatments at low temperatures (i.e. below 400 C), these benefits can be achieved without compromising corrosion resistance. Here a variety of surface analysis and depth profiling techniques have been used to determine the physical and mechanical properties of carbon-rich layers produced on a range of stainless steel substrate materials. X-ray diffraction (XRD) was employed to determine the crystallographic structure, whilst wavelength dispersive X-ray analysis (WDX) and glow discharge optical spectroscopy (GDOS) gave information on the concentration and distribution of the diffused species within the treated layers. A variety of carbide-based structures was detected, including the expected M 23 C 6 and, more surprisingly, M 3 C. Optical and electron microscopy techniques were used to provide information on layer morphology. The surfaces produced by the low-temperature carbon-diffusion process generally exhibit a distinct diffusion layer of between 1 and 20 μm, depending on the material and the treatment conditions. Austenitic stainless steels appear to give the best response to treatment, however other types of stainless steel can be treated, particularly if the microstructure contains above 5% retained austenite. Here we discuss the changes in mechanical and metallurgical properties provided by this technique and its potential value for treatment of both austenitic and other stainless steel substrate materials. (orig.)

Comparison of carbon footprints of steel versus concrete pipelines for water transmission.

Science.gov (United States)

Chilana, Lalit; Bhatt, Arpita H; Najafi, Mohammad; Sattler, Melanie

2016-05-01

The global demand for water transmission and service pipelines is expected to more than double between 2012 and 2022. This study compared the carbon footprint of the two most common materials used for large-diameter water transmission pipelines, steel pipe (SP) and prestressed concrete cylinder pipe (PCCP). A planned water transmission pipeline in Texas was used as a case study. Four life-cycle phases for each material were considered: material production and pipeline fabrication, pipe transportation to the job site, pipe installation in the trench, and operation of the pipeline. In each phase, the energy consumed and the CO2-equivalent emissions were quantified. It was found that pipe manufacturing consumed a large amount of energy, and thus contributed more than 90% of life cycle carbon emissions for both kinds of pipe. Steel pipe had 64% larger CO2-eq emissions from manufacturing compared to PCCP. For the transportation phase, PCCP consumed more fuel due to its heavy weight, and therefore had larger CO2-eq emissions. Fuel consumption by construction equipment for installation of pipe was found to be similar for steel pipe and PCCP. Overall, steel had a 32% larger footprint due to greater energy used during manufacturing. This study compared the carbon footprint of two large-diameter water transmission pipeline materials, steel and prestressed concrete cylinder, considering four life-cycle phases for each. The study provides information that project managers can incorporate into their decision-making process concerning pipeline materials. It also provides information concerning the most important phases of the pipeline life cycle to target for emission reductions.

Fatigue crack growth rate of API X70 steel pipelines under spectrum loading

International Nuclear Information System (INIS)

Beden, S.M.; Abdullah, S.; Ariffin, A.K.

2012-01-01

Pipelines offer the most efficient way to transport bulk quantities of gas and oil, either from points of production to storage locations or from storage locations to distributed points of end use. As one of the main materials of west–east gas transmission pipes, X70 pipelines usually serve under variable amplitude loading (VAL). Base on the importance of in-service API X70 pipelines, it is important for the safe operation of this system to know its behaviour under VAL. This paper focuses on the ability of using the NASGRO model to predict the fatigue crack growth (FCG), based on investigation with the modified Wheeler model and experimental data. The results show that the NASGRO model give a fatigue life near by to that published in literatures and also showed the FCG rate response of X70 pipeline steels when exposed to VAL with different overload values. Extra modification to the NASGRO model may lead to better representing of FCG rate. Highlights: ► The assessment of fatigue crack propagation under different load histories are proposed and presented in this paper. ► Due to lack of knowledge in the related area, as yet no universal model exists. ► The output was based on both simulation and experiments. The simulation part was carried out based on the NASGRO model. ► This work focus on fatigue crack growth (FCG) and fatigue life based on the comparison with the previous work.

A quality approach to maintain the properties of S235 JR structural carbon steel in Lebanon

International Nuclear Information System (INIS)

Sidawi, J.A.; Al Khatib, H.

2004-01-01

Full text.S235JR carbon steel is one of the most popular steels used in Lebanon. It is imported by steel dealers and is widely used by all fabricators and manufacturers of steels for many structural purposes and applications. This kind of steel has good ductile properties as well as excellent weldability. It is still known by its previous designation St 37-2 or E 24-2. S235JR is produced in many shapes and thicknesses such as steel plates, sheets, angles and different other geometric shapes. Standard chemical and mechanical tests were conducted and reported on S235JR hot-rolled structural low-carbon mild steel specimens collected from Lebanese steel market. The main objective of this work is to assure the compliance of these properties with those set by the steel manufacturer. The above mentioned tests were performed at the laboratories of the Industrial Research Institute (IR) in Lebanon to assure the quality and credibility of the results. related European and American standards were presented as references and compared with the achieved results. Discussion was presented to show the similarities and differences between S235JR steel samples and standard requirements. Some of the reasons for such differences were discussed. Sufficient data was furnished through this work for the public and mainly for the Lebanese Standard Organization LIBNOR to easily adopt and implement the EN 10025:1993 European standard that can be applied in Lebanon concerning the most commonly used hot rolled low carbon structural steel. A follow up concerning adopting and implementing EN 10025:1993 will be briefed

Preparation of diamond like carbon thin film on stainless steel and ...

Indian Academy of Sciences (India)

Diamond-like carbon; buffer layer; plasma CVD; surface characterization; biomedical applications. Abstract. We report the formation of a very smooth, continuous and homogeneous diamond-like carbon DLC thin coating over a bare stainless steel surface without the need for a thin Si/Cr/Ni/Mo/W/TiN/TiC interfacial layer.

Measurement of carbon activity in sodium and steel and the behaviour of carbon-bearing species

International Nuclear Information System (INIS)

Rajendran Pillai, S.; Ranganathan, R.; Mathews, C.K.

1988-01-01

Carburization or decarburization of structural materials in a sodium system depends on the local differences in carbon activity. The behaviour of carbon-bearing species in sodium influences its carbon activity. In order to understand the behaviour of carbon in these systems, an electrochemical carbon meter was fabricated in our laboratory. The original version of this meter was capable of operating in the temperature range of 850-980 K. Studies are carried out to extend this lower limit of temperature. Employing the carbon meter, experiments were carried out to understand the behaviour of carbon-bearing species. Gas equilibration experiments were also carried out with the same view. A new method for measuring the carbon activity in steels are described which employs the carbon meter. A review on these investigations and the conclusions reached on the behaviour of carbon in fast reactor loops are described

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

...)] 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 carbon... respect to circular welded carbon-quality steel pipe from Oman and the United Arab Emirates being sold in...

75 FR 69125 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China

Science.gov (United States)

2010-11-10

... with material injury by reason of imports from China of certain seamless carbon and alloy steel standard, line, and pressure pipe (``seamless SLP pipe''), provided for in subheadings 7304.19.10, 7304.19... Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China Determination On the basis of...

Effect of microstructural variation on the Cu/CK45 carbon steel friction weld joint

Energy Technology Data Exchange (ETDEWEB)

Lee, W.B.; Jung, S.B. [Advanced Materials and Process Research Center for IT, Sungkyunkwan Univ., Gyounggi-do (Korea)

2003-12-01

The mechanical properties of friction-welded pure Cu/CK45 carbon steel joints have been studied. The joint strength increased with increasing upset pressure till it reached a critical value. However, the joint strength was fixed at a low strength with increasing friction time, compared to that of the Cu base metal. The hardness near the interface at the Cu side was softer than that of the base metal due to the dynamically recrystallized and annealed grain. The width of the softened region became wider with increasing friction time and decreasing upset pressure. But the hardness of the CK45 carbon steel side showed a slightly higher value than that of the base metal. This result was explained by the formation of martensite structure at the CK45 carbon steel side during the welding process. (orig.)

Effect of carbon activity on the creep behaviour of 21/4Cr, 1Mo steel in sodium

International Nuclear Information System (INIS)

Cordwell, J.E.; Charnock, W.; Nicholson, R.D.

1979-02-01

The creep endurance and creep cracking behaviour of 2 1/4Cr, 1Mo steel in sodium at 475 0 C have been studied at three different sodium carbon activities. Creep endurance was found to increase with increasing carbon activity of the sodium. Tests carried out in high carbon activity sodium were discontinued before fracture. Creep crack initiation displacement at notches decreased with increasing carbon activity, presumably as a result of notch tip carburisation. The plastic zones at the tips of blunt notches in specimens exposed in high carbon activity sodium were preferentially carburised. These observations were similar to those made previously on 9Cr, 1Mo steel. One difference detected metallographically was that in a high carburising environment uniform carburisation was obtained in the 2 1/4Cr, 1Mo steel specimens whereas carburisation gradients were observed in the 9Cr, 1Mo steel. Creep crack propagation rates for given notch opening displacement rates in low and intermediate carbon activity sodium were indistinguishable. However, the strenthening that resulted from the mild carburisation of the specimen in the intermediate carbon activity sodium caused slower notch opening displacement rates and crack propagation rates than in the low carbon activity sodium, when the rates were compared at the same crack length. (author)

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.

Influence of the impurities on the depth of penetration with carbon steel weldings

Directory of Open Access Journals (Sweden)

O. Savytsky

2014-04-01

Full Text Available In this paper the results of the research about the influence of the impurities on the depth of penetration with carbon steels weldings of different chemical composition are presented. These data suggest that presence of those impurities, such as sulphure and oxygen, in the steel, increases the depth of penetration to 1,3 - 1,5 times compared to welding refined steels. Applying activating fluxes for welding high tensile steels, provides an increase in the depth of penetration of 2 - 3 times.

Corrosion of carbon steel and low-alloy steel in diluted seawater containing hydrazine under gamma-rays irradiation

International Nuclear Information System (INIS)

Nakano, Junichi; Yamamoto, Masahiro; Tsukada, Takashi

2014-01-01

Seawater was injected into reactor cores of Units 1, 2, and 3 in the Fukushima Daiichi nuclear power station as an urgent coolant. It is considered that the injected seawater causes corrosion of steels of the reactor pressure vessel and primary containment vessel. To investigate the effects of gamma-rays irradiation on weight loss in carbon steel and low-alloy steel, corrosion tests were performed in diluted seawater at 50°C under gamma-rays irradiation. Specimens were irradiated with dose rates of 4.4 kGy/h and 0.2 kGy/h. To evaluate the effects of hydrazine (N 2 H 4 ) on the reduction of oxygen and hydrogen peroxide, N 2 H 4 was added to the diluted seawater. In the diluted seawater without N 2 H 4 , weight loss in the steels irradiated with 0.2 kGy/h was similar to that in the unirradiated steels, and weight loss in the steels irradiated with 4.4 kGy/h increased to approximate 1.7 times of those in the unirradiated steels. Weight loss in the steels irradiated in the diluted seawater containing N 2 H 4 was similar to that in the diluted seawater without N 2 H 4 . When N 2 was introduced into the gas phase in the flasks during gamma-rays irradiation, weight loss in the steels decreased. (author)

Microstructure and properties of SA 106B carbon steel after treatment of the melt with nano-sized TiC particles

International Nuclear Information System (INIS)

Park, Jin-Ju; Hong, Sung-Mo; Park, Eun-Kwang; Kim, Kyeong-Yeol; Lee, Min-Ku; Rhee, Chang-Kyu

2014-01-01

Carbon steel dispersed with nano-sized TiC ceramic particles was fabricated using the liquid metal casting process by means of their ex-situ introduction. For this purpose, the nano-sized TiC powders with an initial average size of 40 nm were first mechanically activated with two metal powders (Fe, Ni) and then introduced externally into the molten carbon steel during the casting process. According to the chemical composition analysis, 90% of the initial TiC nanoparticles were discovered within the cast carbon steel. Compared to cast carbon steel without TiC nanoparticles, the grain size refinement and mechanical property enhancement were achieved. Atom probe tomographic analysis revealed that the TiC nanoparticles were approximately 30 nm in size in the carbon steel matrix with a number density of 1.49×10 21 m −3

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

Science.gov (United States)

2010-04-09

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time Limit for Preliminary Results of... countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea. See Countervailing...

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

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2012-03-22

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...

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

Science.gov (United States)

2011-04-14

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...

Holographic interferometry as electrochemical emission spectroscopy of carbon steel in seawater with low concentration of RA-41 corrosion inhibitor

International Nuclear Information System (INIS)

Habib, K.; Al-Muhana, K.; Habib, A.

2009-01-01

In the present investigation, holographic interferometry was utilized for the first time to determine the rate change of the number of the fringe evolutions during the corrosion test of carbon steel in blank seawater and with seawater with different concentrations of a corrosion inhibitor. In other words, the anodic dissolution behaviors (corrosion) of the carbon steel were determined simultaneously by holographic interferometry, an electromagnetic method, and by the electrochemical impedance (EI) spectroscopy, an electronic method. So, the abrupt rate change of the number of the fringe evolutions during corrosion test (EI) spectroscopy, of the carbon steel is called electrochemical emission spectroscopy. The corrosion process of the steel samples was carried out in blank seawater and seawater with different concentrations, 5-20 ppm, of RA-41 corrosion inhibitor using the EI spectroscopy method, at room temperature. The electrochemical emission spectra of the carbon steel in different solutions represent a detailed picture of the rate change of the anodic dissolution of the steel throughout the corrosion processes. Furthermore, the optical interferometry data of the carbon steel were compared to the data, which were obtained from the EI spectroscopy. Consequently, holographic interferometric is found very useful for monitoring the anodic dissolution behaviors of metals, in which the number of the fringe evolutions of the steel samples can be determined in situ. (Author)

Corrosion of austenitic and ferritic-martensitic steels exposed to supercritical carbon dioxide

International Nuclear Information System (INIS)

Tan, L.; Anderson, M.; Taylor, D.; Allen, T.R.

2011-01-01

Highlights: → Oxidation is the primary corrosion phenomenon for the steels exposed to S-CO 2 . → The austenitic steels showed significantly better corrosion resistance than the ferritic-martensitic steels. → Alloying elements (e.g., Mo and Al) showed distinct effects on oxidation behavior. - Abstract: Supercritical carbon dioxide (S-CO 2 ) is a potential coolant for advanced nuclear reactors. The corrosion behavior of austenitic steels (alloys 800H and AL-6XN) and ferritic-martensitic (FM) steels (F91 and HCM12A) exposed to S-CO 2 at 650 deg. C and 20.7 MPa is presented in this work. Oxidation was identified as the primary corrosion phenomenon. Alloy 800H had oxidation resistance superior to AL-6XN. The FM steels were less corrosion resistant than the austenitic steels, which developed thick oxide scales that tended to exfoliate. Detailed microstructure characterization suggests the effect of alloying elements such as Al, Mo, Cr, and Ni on the oxidation of the steels.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

International Nuclear Information System (INIS)

Henshall, G.A.

1996-11-01

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

Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

International Nuclear Information System (INIS)

Flores, Eugenio A.; Olivares, Octavio; Likhanova, Natalya V.; Dominguez-Aguilar, Marco A.; Nava, Noel; Guzman-Lucero, Diego; Corrales, Monica

2011-01-01

Highlights: → N-Alkyl-sodium phthalamates as corrosion inhibitors for industry in acidic medium. → Compounds behaved as mixed type inhibitors and followed Langmuir adsorption isotherm. → Efficiencies were proportional to aliphatic chain length and inhibitor concentration. → Iron complexes and chelates with phthalamates contributed to carbon steel protection. - Abstract: Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42-86% at 25 deg. C and 25-60% at 40 o C. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe +2 complexes and Fe +2 chelates with phthalamates prevented steel from further corrosion.

77 FR 25405 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

Science.gov (United States)

2012-04-30

... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for the Preliminary Results of...

76 FR 21332 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

Science.gov (United States)

2011-04-15

... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...

75 FR 25841 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

Science.gov (United States)

2010-05-10

... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...

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

Science.gov (United States)

2012-04-27

...-Resistant Carbon Steel Flat Products From Germany and South Korea: Extension of Time Limits for Preliminary...) orders on corrosion-resistant carbon steel flat products (CORE) from Germany and South Korea (Korea... from Germany and South Korea: Adequacy Redetermination Memorandum,'' (April 20, 2012). The preliminary...

Production of metal fullerene surface layer from various media in the process of steel carbonization

Directory of Open Access Journals (Sweden)

KUZEEV Iskander Rustemovich

2018-04-01

Full Text Available Studies devoted to production of metal fullerene layer in steels when introducing carbon from organic and inorganic media were performed. Barium carbonate was used as an inorganic medium and petroleum pitch was used as an organic medium. In order to generate the required amount of fullerenes in the process of steel samples carbonization, optimal temperature mode was found. The higher temperature, absorption and cohesive effects become less important and polymeric carbon structures destruction processes become more important. On the bottom the temperature is limited by petroleum pitch softening temperature and its transition to low-viscous state in order to enhance molecular mobility and improve the possibility of their diffusion to metal surface. Identification of fullerenes in the surface modified layer was carried out following the methods of IR-Fourier spectrometry and high-performance liquid chromatography. It was found out that nanocarbon structures, formed during carbonization in barium carbonate and petroleum pitch mediums, possess different morphology. In the process of metal carbonization from carbonates medium, the main role in fullerenes synthesis is belonged to catalytic effect of surface with generation of endohedral derivatives in the surface layer; but in the process of carbonization from pitch medium fullerenes are formed during crystallization of the latter and crystallization centers are of fullerene type. Based on theoretical data and dataof spectral and chromatographic analysis, optimal conditions of metal fullerene layer formation in barium carbonate and petroleum pitch mediums were determined. Low cohesion of layer, modified in barium carbonate medium, with metal basis was discovered. That was caused by limited carbon diffusion in the volume of α-Fe. According to the detected mechanism of fullerenes formation on steel surface in gaseous medium, fullerenes are formed on catalytic centers – ferrum atoms, forming thin metal

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.

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

Science.gov (United States)

2012-05-30

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-350 and 731-TA-616 and 618 (Third Review)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five-Year Reviews... corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion...

76 FR 68208 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, United Arab Emirates, and Vietnam...

Science.gov (United States)

2011-11-03

... (Preliminary)] Circular Welded Carbon-Quality Steel Pipe From India, Oman, United Arab Emirates, and Vietnam... carbon-quality steel pipe from India, Oman, United Arab Emirates, and Vietnam, provided for in... Governments of India, Oman, United Arab Emirates, and Vietnam. Unless the Department of Commerce extends the...

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

International Nuclear Information System (INIS)

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

1997-01-01

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

Characterization of carbon ion implantation induced graded microstructure and phase transformation in stainless steel

Energy Technology Data Exchange (ETDEWEB)

Feng, Kai; Wang, Yibo [Shanghai Key laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, Zhuguo, E-mail: lizg@sjtu.edu.cn [Shanghai Key laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

2015-08-15

Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 10{sup 17} ions-cm{sup −} {sup 2}, 2.4 × 10{sup 17} ions-cm{sup −} {sup 2}, and 4.8 × 10{sup 17} ions-cm{sup −} {sup 2}. The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. - Highlights: • Carbon implantation leads to phase transformation from austenite to ferrite. • The passive film on SS316L becomes thinner after carbon ion implantation. • An amorphous layer is formed by carbon ion implantation. • Nanophase precipitate from amorphous layer at higher ion implantation fluence. • Corrosion resistance of SS316L is improved by carbon implantation.

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

International Nuclear Information System (INIS)

BOOMER, K.D.

2007-01-01

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

Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65; Estudio comparativo de la corrosion inducida por microorganismos sulfatorreductores, en un acero inoxidable 304L sensibilizado y un acero al carbono API X65

Energy Technology Data Exchange (ETDEWEB)

Diaz S, A.; Gonzalez F, E.; Arganis J, C.; Luna C, P.; Carapia M, L. [ININ, Carretera Mexico-Toluca Km. 36.5, 52045 Estado de Mexico (Mexico)]. e-mail: ads@nuclear.inin.mx

2004-07-01

In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

The performance of a surface-applied corrosion inhibitor for the carbon steel in saturated Ca(OH)2 solutions

International Nuclear Information System (INIS)

Zheng, Haibing; Li, Weihua; Ma, Fubin; Kong, Qinglin

2014-01-01

In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH) 2 solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH) 2 solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface

Yttrium implantation effects on extra low carbon steel and pure iron

Energy Technology Data Exchange (ETDEWEB)

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

1999-05-25

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

Corrosion Inhibitor of Carbon Steel from Onion Peel Extract

Directory of Open Access Journals (Sweden)

Muhammad Samsudin Asep

2018-01-01

Full Text Available Carbon steels composed by two main elements, they are iron (Fe and carbon (C elements which widely used in industrial because of its resistance and more affordable than stainless steel, but their weakness is they have low corrosion resistance. One way to modify carbon steel is by coating them with antioxidant compounds that can delay, slow down, and prevent lipid oxidation process, which obtained from onion peel extract. Several studies on corrosion inhibitors have been performed. However, the efficiency was not reach the optimum. This study aims to examine the effect of onion peel extract concentration on the efficiency of corrosion inhibitor and characterization of the green corrosion inhibitor from onion peel extract. This research method begins by extracting onion peel to 200 ml solvent which we use aquadest and methanol and mixed with 5 grams of crushed onion peel, then let them be extracted for 60 minutes with room temperature. Once it was filtered and the solution obtained, followed by evaporating process with rotary evaporator to decrease the content of solvent. The product is ready to be used as a green corrosion inhibitor of carbon steel in 1 mol/L HCl. While the analysis used is HPLC qualitative analysis, and electroplatting process. The impedance is measured at a frequency of 100 kHz to 4 mHz with an AC current of 10mV. Inhibitor concentrations are vary between 2 ml and 4 ml of onion peel extract. Electroplatting is done within 30 minutes with 10 minutes each checking time. Furthermore, quantitative analysis was done for the analysis of corrosion rate and weight loss. Based on HPLC analysis, it is known that the extract of onion peel contains 1mg/L of quercetin, which is belong to flavonoid group as green inhibitor. While electroplatting process, aquadest solvent having average efficiency of 99,57% for 2 ml of extract, and 99,60% for 4 ml of extract. Methanol solvent having average efficiency of 99,52% for 2 ml of extract and 99

Efficiency and corrosion rate analysis of organic inhibitor utilization from bawang dayak leaves (EleutherineamericanaMerr.) on API 5L steel

Science.gov (United States)

Sari, Shaimah Rinda; Sari, Eli Novita; Rizky, Yoel; Sulistijono, Triana, Yunita

2018-05-01

This research studied the inhibition of corrosion by bawang dayak leaves extract (EleutherineamericanaMerr.) on API 5L steel in brine water environment (3.5% NaCl). The inhibitor was extracted using maceration process from bawang dayak leaves that was cultivated in Paser District, East Kalimantan. The test of antioxidant activity showed that bawang dayak leaves extract is a very powerful antioxidant with IC50 value of 27.30204. The results from FTIR test show the presence of electronegative atoms and double bonds of the alkenes groups that provide the potential of the extract as a corrosion inhibitor. Efficiency of inhibition reached up to 93.158% for the addition of inhibitor with 300 ppm concentration and 20 days of immersion time. This inhibitory behavior is also supported by polarization measurements where the lowest corrosion rate of 0.00128 mm/year is obtained at the same concentration and immersion time.

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

NARCIS (Netherlands)

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

2017-01-01

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

Drug Interaction API

Data.gov (United States)

U.S. Department of Health & Human Services — The Interaction API is a web service for accessing drug-drug interactions. No license is needed to use the Interaction API. Currently, the API uses DrugBank for its...

Zn-10.2% Fe coating over carbon steel atmospheric corrosion resistance. Comparison with zinc coating

International Nuclear Information System (INIS)

Arnau, G.; Gimenez, E.; Rubio, M.V.; Saura, J.J.; Suay, J.J.

1998-01-01

Zn-10.2% Fe galvanized coating versus hot galvanized coating over carbon steel corrosion performance has been studied. Different periods of atmospheric exposures in various Valencia Community sites, and salt spray accelerated test have been done. Carbon steel test samples have been used simultaneously in order to classify exposure atmosphere corrosivity, and environmental exposure atmosphere characteristics have been analyzed. Corrosion Velocity versus environmental parameters has been obtained. (Author) 17 refs

Preliminary study on the corrosion behavior of carbon steel in Horonobe groundwater environment

International Nuclear Information System (INIS)

Taniguchi, Naoki; Kogawa, Noritaka; Maeda, Kazuto

2006-08-01

It is necessary to understand the corrosion behavior of candidate overpack materials to plan the in-situ engineered barrier test at underground laboratory constructing at Horonobe and to design the overpacks suitable to Horonobe environment. The preliminary corrosion tests of carbon steel which is a candidate material for overpacks were carried out using artificial groundwater and actual groundwater sampled at Horonobe. As the results of anodic polarization experiments, the anodic polarization curves of carbon steel in buffer material were active dissolution type, and the corrosion type of carbon steel in Horonobe groundwater environment was expected to be general corrosion. The results of immersion test under air equilibrium condition showed that the degrees of corrosion localization were not exceeded the data obtained in previous studies. The trend of corrosion rates in buffer material under anaerobic condition were similar to the data obtained in previous studies. Based on the experimental results, it was confirmed that the corrosion assessment model and assumed corrosion rate in second progress report (H12 report) can be applied to the assessment for Horonobe groundwater condition. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-04-26

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

Effect of carbonate in slightly alkaline medium on the corrosion of maraging steel

International Nuclear Information System (INIS)

Bellanger, G.

1994-01-01

This study was carried out to ascertain the behavior of maraging steel identified as AMS. 65-12 and used in the tanks of the French plant for the reprocessing of radioactive water. This water has a pH of 9 and contains carbonate ions. The rest or corrosion potentials can be in the transpassive or active region due to radiolytic species. Therefore, the behavior of maraging steel was studied in these two regions. In the neighborhood of the active-passive transition potentials, maraging steel is corroded by means of intermediates. The corrosion potential does not change with carbonate at a constant pH. With carbonate and a low scan rate, the breakdown transpassive potentials are displaced towards more positive potentials and the passive potential region is broader, while at a high scan rate these potentials are displaced towards more negative values. After the beginning of the reverse scan, the current is again positive. These suggest that the corrosion kinetics are not the same. The diffusion coefficient of species inside the oxide layer was determined. ((orig.))

Rapid nickel diffusion in cold-worked carbon steel at 320-450 °C

Science.gov (United States)

Arioka, Koji; Iijima, Yoshiaki; Miyamoto, Tomoki

2015-11-01

The diffusion coefficient of nickel in cold-worked carbon steel was determined with the diffusion couple method in the temperature range between 320 and 450 °C. Diffusion couple was prepared by electro-less nickel plating on the surface of a 20% cold-worked carbon steel. The growth in width of the interdiffusion zone was proportional to the square root of diffusion time to 12,000 h. The diffusion coefficient (DNi) of nickel in cold-worked carbon steel was determined by extrapolating the concentration-dependent interdiffusion coefficient to 0% of nickel. The temperature dependence of DNi is expressed by DNi = (4.5 + 5.7/-2.5) × 10-11 exp (-146 ± 4 kJ mol-1/RT) m2s-1. The value of DNi at 320 °C is four orders of magnitude higher than the lattice diffusion coefficient of nickel in iron. The activation energy 146 kJ mol-1 is 54% of the activation energy 270.4 kJ mol-1 for lattice diffusion of nickel in the ferromagnetic state iron.

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

Mass attenuation coefficients, effective atomic and electron numbers of stainless steel and carbon steels with different energies

International Nuclear Information System (INIS)

Mohd Fakarudin Abdul Rahman; Mohd Iqbal Saripan; Nor Paiza Mohamad Hasan; Ismail Mustapha

2011-01-01

The total mass attenuation coefficients (μ/ ρ) of stainless steel (SS316L) and carbon steel (A516) that are widely used as petrochemical plant components, such as distillation column, heat exchanger, boiler and storage tank were measured at 662, 1073 and 1332 keV of photon energies. Measurements of radiation intensity for various thicknesses of steel were made by using transmission method. The γ-ray intensity were counted by using a Gamma spectrometer that contains a Hyper-pure Germanium (HPGe) detector connected with Multi Channel Analyzer (MCA). The effective numbers of atomic (Z eff ) and electron (N eff ) obtained experimentally were compared by those obtained through theoretical calculation. Both experimental and calculated values of Z eff and N eff were in good agreement. (author)

Comparison between instrumented precracked Charpy and compact specimen tests of carbon steels

International Nuclear Information System (INIS)

Nanstad, R.K.

1980-01-01

The General Atomic Company High Temperature Gas-Cooled Reactor (HTGR) is housed within a prestressed concrete reactor vessel (PCRV). Various carbon steel structural members serve as closures at penetrations in the vessel. A program of testing and evaluation is underway to determine the need for reference fracture toughness (K/sub IR/) and indexing procedures for these materials as described in Appendix G to Section III, ASME Code for light water reactor steels. The materials of interest are carbon steel forgings (SA508, Class 1) and plates (SA537, Classes 1 and 2) as well as weldments of these steels. The fracture toughness behavior is characterized with instrumented precracked Charpy V-votch specimens (PCVN) - slow-bend and dynamic - and compact specimens (10-mm and 25-mm thicknesses) using both linear elastic (ASTM E399) and elastic-plastic (equivalent Energy and J-Integral) analytical procedures. For the dynamic PCVN tests, force-time traces are analyzed according to the procedures of the Pressure Vessel Research Council (PVRC)/Metal Properties Council (MPC). Testing and analytical procedures are discussed and PCVN results are compared to those obtained with compact specimens

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

Directory of Open Access Journals (Sweden)

Mingxing Zhou

2017-07-01

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

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

2017-06-01

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.

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 evolutio...

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

Science.gov (United States)

2010-07-22

...)] 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: The... Japan, and the suspended investigation on hot-rolled steel from Russia would be likely to lead to...

75 FR 62566 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

Science.gov (United States)

2010-10-12

...)] Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... antidumping duty investigation on hot-rolled steel from Russia. SUMMARY: The Commission hereby gives notice of... suspended investigation on hot-rolled steel from Russia would be likely to lead to continuation or...

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

Science.gov (United States)

2013-03-14

... Indonesia P.T. Krakatau Steel 10.21 All Others 10.21 Thailand Sahaviriya Steel Industries Public Company...] Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, and Thailand: Final Results of... products (``HR steel'') from India, Indonesia, and Thailand pursuant to section 751(c) of the Tariff Act of...

Kinetics of electrochemical boriding of low carbon steel

International Nuclear Information System (INIS)

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

2011-01-01

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

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

2017-11-01

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.

Metallurgy and mechanical properties variation with heat input,during dissimilar metal welding between stainless and carbon steel

Science.gov (United States)

Ramdan, RD; Koswara, AL; Surasno; Wirawan, R.; Faturohman, F.; Widyanto, B.; Suratman, R.

2018-02-01

The present research focus on the metallurgy and mechanical aspect of dissimilar metal welding.One of the common parameters that significantly contribute to the metallurgical aspect on the metal during welding is heat input. Regarding this point, in the present research, voltage, current and the welding speed has been varied in order to observe the effect of heat input on the metallurgical and mechanical aspect of both welded metals. Welding was conducted by Gas Metal Arc Welding (GMAW) on stainless and carbon steel with filler metal of ER 309. After welding, hardness test (micro-Vickers), tensile test, macro and micro-structure characterization and Energy Dispersive Spectroscopy (EDS) characterization were performed. It was observed no brittle martensite observed at HAZ of carbon steel, whereas sensitization was observed at the HAZ of stainless steel for all heat input variation at the present research. Generally, both HAZ at carbon steel and stainless steel did not affect tensile test result, however the formation of chromium carbide at the grain boundary of HAZ structure (sensitization) of stainless steel, indicate that better process and control of welding is required for dissimilar metal welding, especially to overcome this issue.

Radiofrequency cold plasma nitrided carbon steel: Microstructural and micromechanical characterizations

International Nuclear Information System (INIS)

Bouanis, F.Z.; Bentiss, F.; Bellayer, S.; Vogt, J.B.; Jama, C.

2011-01-01

Highlights: → C38 carbon steel samples were plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge. → RF plasma treatment enables nitriding for non-heated substrates. → The morphological and chemical analyses show the formation of a uniform thickness on the surface of the nitrided C38 steel. → Nitrogen plasma active species diffuse into the samples and lead to the formation of Fe x N. → The increase in microhardness values for nitrided samples with plasma processing time is interpreted by the formation of a thicker nitrided layer on the steel surface. - Abstract: In this work, C38 carbon steel was plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge on non-heated substrates. General characterizations were performed to compare the chemical compositions, the microstructures and hardness of the untreated and plasma treated surfaces. The plasma nitriding was carried out on non-heated substrates at a pressure of 16.8 Pa, using N 2 gas. Surface characterizations before and after N 2 plasma treatment were performed by means of the electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Vickers microhardness measurements. The morphological and chemical analysis showed the formation of a uniform structure on the surface of the nitrided sample with enrichment in nitrogen when compared to untreated sample. The thickness of the nitride layer formed depends on the treatment time duration and is approximately 14 μm for 10 h of plasma treatment. XPS was employed to obtain chemical-state information of the plasma nitrided steel surfaces. The micromechanical results show that the surface microhardness increases as the plasma-processing time increases to reach, 1487 HV 0.005 at a plasma processing time of 8 h.

Radiofrequency cold plasma nitrided carbon steel: Microstructural and micromechanical characterizations

Energy Technology Data Exchange (ETDEWEB)

Bouanis, F.Z. [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Bellayer, S.; Vogt, J.B. [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Jama, C., E-mail: charafeddine.jama@ensc-lille.fr [Universite Lille Nord de France, F-59000 Lille (France); Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)

2011-05-16

Highlights: {yields} C38 carbon steel samples were plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge. {yields} RF plasma treatment enables nitriding for non-heated substrates. {yields} The morphological and chemical analyses show the formation of a uniform thickness on the surface of the nitrided C38 steel. {yields} Nitrogen plasma active species diffuse into the samples and lead to the formation of Fe{sub x}N. {yields} The increase in microhardness values for nitrided samples with plasma processing time is interpreted by the formation of a thicker nitrided layer on the steel surface. - Abstract: In this work, C38 carbon steel was plasma nitrided using a radiofrequency (rf) nitrogen plasma discharge on non-heated substrates. General characterizations were performed to compare the chemical compositions, the microstructures and hardness of the untreated and plasma treated surfaces. The plasma nitriding was carried out on non-heated substrates at a pressure of 16.8 Pa, using N{sub 2} gas. Surface characterizations before and after N{sub 2} plasma treatment were performed by means of the electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Vickers microhardness measurements. The morphological and chemical analysis showed the formation of a uniform structure on the surface of the nitrided sample with enrichment in nitrogen when compared to untreated sample. The thickness of the nitride layer formed depends on the treatment time duration and is approximately 14 {mu}m for 10 h of plasma treatment. XPS was employed to obtain chemical-state information of the plasma nitrided steel surfaces. The micromechanical results show that the surface microhardness increases as the plasma-processing time increases to reach, 1487 HV{sub 0.005} at a plasma processing time of 8 h.

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

Microstructure Evolution and Chemical Analysis on Carbon Steels and Fe-Cr-Mo Alloys after FAC Simulation Tests

International Nuclear Information System (INIS)

Kim, Seunghyun; Kim, Taeho; Lee, Yun Ju; Kim, Ji Hyun

2017-01-01

Flow-accelerated corrosion (FAC) is an environment assisted degradation of structural materials, which usually occurs in pipelines of power plants. There have been many studies to investigate the fundamental mechanism and corresponding countermeasures against FAC, and recently the carbon steels have been replaced by ASTM A 335 P22, which contains approximately 2.2 wt.% of Cr and 1 wt.% of Mo. By enhancing passivity of P22 by Cr, it is reported that FAC rate has been greatly reduced. However, while corrosion behavior of Fe-based alloys is relatively well known, their behavior under high-temperature flowing water is not well investigated. In other words, effects of Cr and its corrosion and oxidation behavior is not clearly revealed. Furthermore, it is known that Mo enhances the pitting corrosion resistance of alloys however its mechanism is not clearly investigated. Recently, replacement of Mo in alloy contents has been widely studied because of the cost of Mo. Carbon steels undergo severe environmental-assisted degradation behavior so called FAC, and as its countermeasure the carbon steel has been replaced by P22 which contains Cr and Mo. It is generally known that Cr and Mo enhances passivity of Fe-based alloys however their corrosion and oxidation behavior has not been fully investigated especially in high-temperature flowing water environments. In this study, we employed HRTEM and synchrotron XAS techniques in order to investigate detailed microstructure evolution and chemical bonding of the commercialized carbon steel and the Fe-Cr-Mo alloys. From the analysis, it is found that while carbon steels exhibit porous oxide P22 exhibit oxide structures with thin Cr-rich oxide and spinel. Therefore, carbon steel undergoes severe FAC compared to P22 however effects of Cr and Mo and their behavior in high-temperature flowing water will be investigated.

Study of API 5L X70 steel corrosion processes when in contact with some Brazilian soils; Estudo dos processos de corrosao de acos API 5L X70 em contato com alguns dos solos do Brasil

Energy Technology Data Exchange (ETDEWEB)

Jesus, Sergio Luis de

2007-07-01

Pipelines, fuel storage tanks and other metallic structures are in permanent contact and exposed to different types of soils, of horizons or layers, or of soil aggressiveness. This interaction may cause expressive damages to the environment and to the planned work. Contamination may occur due to leakage of stored products, splitting during transportation, accidents caused by pipelines without extensive maintenance. The result of these accidents could be, among others, some financial losses. In order to recognize the dynamic interactions between metallic surfaces and the environment it is crucial to have preventive actions and to develop better-applied materials. API steel 5L X70 has been used in structures of low and high pressure with high mechanical strength and corrosion and, even so, it is susceptible to etching corrosion since it is in contact with different environments from mangrove regions to industrial environments. The present case evaluated the role of 5L X70 API steel in contact with different soil horizons representative of the Brazilian soil. This investigation correlated chemical species with solute ions in soil solution, secondary and primary phase minerals besides physical and chemical characteristics as pH, electric conductivity, total dissolved solids, among others, to the results of corrosion resistance and ways of corrosion. The evaluation was carried out using x-ray diffractometry, scanning electron microscopy, total reflection x-ray fluorescence, fuel injection flow besides texture and gravimetric analyses to soil characterization and mineralogy, identification of corrosion products, soil solution analyses, evaluation of tested materials and classification of ways and types of corrosion. This was an attempt to integrate the data to a better understanding of the process involving reagents and products. The results showed that different soil horizons such as different types of analyzed soils produce specific etching in metallic structures

Paying the full price of steel – Perspectives on the cost of reducing carbon dioxide emissions from the steel industry

International Nuclear Information System (INIS)

Rootzén, Johan; Johnsson, Filip

2016-01-01

This study examines the impacts felt downstream of carbon pricing and investments made in CO_2 abatement within the steel industry. Using the supply of steel to a passenger car as a case study, the effects of a steel price increase on cost structures and price at each step of the supply chain were assessed. Since the prices of emission allowances under the European Union Emissions Trading System fall well below those required to unlock investments in low-CO_2 production processes in the integrated steelmaking industry this paper seeks to pave the way for a discussion on complementary policy options. The results of the analysis suggest that passing on the compliance costs of the steel industry would have only marginal impacts on costs and prices for the end-use sectors (e.g., on the production cost or selling price of the passenger car). Under the assumptions made herein, at a carbon price of 100 €/tCO_2, the retail price of a mid-sized European passenger car would have to be increased by approximately 100–125 €/car (<0.5%) to cover the projected increases in steel production costs. - Highlights: • Examines impacts downstream of investments in CO_2 abatement in the steel industry. • Show how investing in low-CO_2 processes have marginal impacts in end-user stage. • Increase in the retail price of a mid-sized passenger car would be well below 1%. • Open up for complementary policies, financing mechanisms or new business models.

75 FR 1335 - Circular Welded Carbon Steel Pipes and Tubes from Taiwan; Extension of Time Limit for Preliminary...

Science.gov (United States)

2010-01-11

... DEPARTMENT OF COMMERCE International Trade Administration [A-583-008] Circular Welded Carbon Steel... review of the antidumping duty order on circular welded carbon steel pipes and tubes from Taiwan.\\1\\ On... review within the original time frame because we require additional time to obtain information from the...

Reinforcement steel corrosion in passive state and by carbonation: Consideration of galvanic currents and interface steel - concrete defaults

International Nuclear Information System (INIS)

Nasser, A.

2010-01-01

This thesis aims to study the durability of nuclear waste deep storage structures. The work carried out is essentially an experimental study, and focuses on the corrosion of steel in the passive state with aerated or non-aerated conditions on the one hand, and the corrosion of steel in carbonated concrete during the propagation phase on the other hand. Indeed, the pore solution of concrete in contact with the metal is alkaline (pH between 12 and 13). Under these conditions, steel reinforced concrete remains passive by forming a stable and protective oxide layer (corrosion of steel in the passive state). This passive layer limits the steel corrosion rate at very low values (negligible on a short life time) but not null. For the nuclear waste storage structures due to a very long life time (up to several hundred years), this low corrosion rate can become a risk. Therefore, it is necessary to study the evolution of the oxide layer growth over time. The objectives of the thesis are to study the influence of the steel-concrete interface quality on reinforcement corrosion in passive and active state, and the possible occurrence of galvanic corrosion currents between different reinforcement steel areas. (author)

Numerical evaluation of multipass welding temperature field in API 5L X80 steel welded joints

Directory of Open Access Journals (Sweden)

J Nóbrega

2016-10-01

Full Text Available Many are the metallurgical changes suffered by materials when subjected to welding thermal cycle, promoting a considerable influence on the welded structures thermo mechanical properties. In project phase, one alternative for evaluating the welding cycle variable, would be the employment of computational methods through simulation. So, this paper presents an evaluation of the temperature field in a multipass welding of API 5L X80 steel used for oil and gas transportation, using the ABAQUS ® software, based on Finite Elements Method (FEM. During the simulation complex phenomena are considerable including: Variation in physical and mechanical properties of materials as a function of temperature, welding speed and the different mechanisms of heat exchange with the environment (convection and radiation were used. These considerations allow a more robust mathematical modeling for the welding process. An analytical heat source proposed by Goldak, to model the heat input in order to characterize the multipass welding through the GTAW (Gas Tungsten Arc Welding process on root and the SMAW (Shielded Metal Arc Welding process for the filling passes were used. So, it was possible to evaluate the effect of each welding pass on the welded joint temperature field, through the temperature peaks and cooling rates values during the welding process.

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-08-15

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

Dynamic recrystallization behavior of a medium carbon vanadium microalloyed steel

International Nuclear Information System (INIS)

Wei, Hai-lian; Liu, Guo-quan; Xiao, Xiang; Zhang, Ming-he

2013-01-01

The dynamic recrystallization behavior of a medium carbon vanadium microalloyed steel was systematically investigated at the temperatures from 900 °C to 1100 °C and strain rates from 0.01 s −1 to 10 s −1 on a Gleeble-1500 thermo-simulation machine. The flow stress constitutive equation of hot deformation for this steel was developed with the activation energy Q being about 273 kJ/mol, which is in reasonable agreement with those reported before. Activation energy analysis showed that vanadium addition in microalloyed steels seemed not to affect the activation energy much. The effect of Zener–Hollomon parameter on the characteristic points of flow curves was studied using the power law relation, and the dependence of critical strain (stress) on peak strain (stress) obeyed a linear equation. Dynamic recrystallization is the most important softening mechanism for the experimental steel during hot compression. The dynamic recrystallization kinetics model of this steel was established based on flow stress and a frequently-used dynamic recrystallization kinetics equation. Dynamic recrystallization microstructure under different deformation conditions was also observed and the dependence of steady-state grain size on the Zener–Hollomon parameter was plotted

Magnetic property variation in carbon steel and chrome-molybdenum steel as a function of uniaxial stress noncoaxial with the magnetic field (abstract)

International Nuclear Information System (INIS)

Sablik, M.J.; Kaminski, D.A.; Jiles, D.C.; Biner, S.B.

1993-01-01

Magnescope 1 magnetic measurements were made on carbon steel specimens ranging from 0.1--0.8 wt %C and on chrome-molybdenum steel specimens cut from electric power plant pipes previously in service. The carbon steel specimens were heat-treated using three procedures: (1) spheroidization, (2) quenching, and (3) quench and tempering. The specimens were subjected to uniaxial tension up to 40 ksi. The inspection head was aligned so that the magnetic field was oriented at different angles with respect to the stress axis. Magnetic properties (such as coercivity and maximum differential permeability) were extracted from digitized magnetic hysteresis loop measurements. Magnetic properties were studied as a function of stress at each angle of stress-field orientation. To our knowledge, such a comprehensive study of noncoaxial stress and field effects has never been accomplished before for such a wide variety of steel specimens. Results for the various materials are presented for different orientation angles and compared to numerical results from the noncoaxial magnetomechanical hysteresis model of Sablik et al. 2

77 FR 15718 - Circular Welded Carbon-Quality Steel Pipe From India, the Sultanate of Oman, the United Arab...

Science.gov (United States)

2012-03-16

...-811] Circular Welded Carbon-Quality Steel Pipe From India, the Sultanate of Oman, the United Arab... Oman (Oman), the United Arab Emirates (UAE), and the Socialist Republic of Vietnam (Vietnam). See Circular Welded Carbon-Quality Steel Pipe From India, the Sultanate of Oman, the United Arab Emirates, and...

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

...)] Circular Welded Carbon-Quality Steel Pipe From India, Oman, The United Arab Emirates, and Vietnam... welded carbon-quality steel pipe from India, Oman, the United Arab Emirates, and Vietnam, provided for in... from India, Oman, the United Arab Emirates, and Vietnam were subsidized and/or dumped within the...

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

... (Preliminary)] Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and... India, Oman, the United Arab Emirates, and Vietnam of circular welded carbon- quality steel pipe... the Governments of India, Oman, the United Arab Emirates, and Vietnam.\\2\\ \\1\\ The record is defined in...

Resolution and sensitivity of the eyes of the Asian honeybees Apis florea, Apis cerana and Apis dorsata.

Science.gov (United States)

Somanathan, Hema; Warrant, Eric J; Borges, Renee M; Wallén, Rita; Kelber, Almut

2009-08-01

Bees of the genus Apis are important foragers of nectar and pollen resources. Although the European honeybee, Apis mellifera, has been well studied with respect to its sensory abilities, learning behaviour and role as pollinators, much less is known about the other Apis species. We studied the anatomical spatial resolution and absolute sensitivity of the eyes of three sympatric species of Asian honeybees, Apis cerana, Apis florea and Apis dorsata and compared them with the eyes of A. mellifera. Of these four species, the giant honeybee A. dorsata (which forages during moonlit nights) has the lowest spatial resolution and the most sensitive eyes, followed by A. mellifera, A. cerana and the dwarf honeybee, A. florea (which has the smallest acceptance angles and the least sensitive eyes). Moreover, unlike the strictly diurnal A. cerana and A. florea, A. dorsata possess large ocelli, a feature that it shares with all dim-light bees. However, the eyes of the facultatively nocturnal A. dorsata are much less sensitive than those of known obligately nocturnal bees such as Megalopta genalis in Panama and Xylocopa tranquebarica in India. The differences in sensitivity between the eyes of A. dorsata and other strictly diurnal Apis species cannot alone explain why the former is able to fly, orient and forage at half-moon light levels. We assume that additional neuronal adaptations, as has been proposed for A. mellifera, M. genalis and X. tranquebarica, might exist in A. dorsata.

Hydrogen degradation of 21-6-9 and medium carbon steel by disc pressure test

International Nuclear Information System (INIS)

Zhou, D.H.; Zhou, W.X.; Xu, Z.L.

1986-01-01

This paper reports the method of disc pressure test and the results for 21-6-9 stainless steel and medium carbon steel in hydrogen gas with different pressures and time of storage. The results show the hydrogen induced degradation of these two kinds of steel. An attempt was made to establish an index which uses variation of area of deformed disc to determine the degradation of ductility in a hydrogen environment. (orig.)

Marine Atmospheric Corrosion of Carbon Steel: A Review.

Science.gov (United States)

Alcántara, Jenifer; Fuente, Daniel de la; Chico, Belén; Simancas, Joaquín; Díaz, Iván; Morcillo, Manuel

2017-04-13

The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter's great importance to human society. About half of the world's population lives in coastal regions and the industrialisation of developing countries tends to concentrate production plants close to the sea. Until the start of the 21st century, research on the basic mechanisms of rust formation in Cl - -rich atmospheres was limited to just a small number of studies. However, in recent years, scientific understanding of marine atmospheric corrosion has advanced greatly, and in the authors' opinion a sufficient body of knowledge has been built up in published scientific papers to warrant an up-to-date review of the current state-of-the-art and to assess what issues still need to be addressed. That is the purpose of the present review. After a preliminary section devoted to basic concepts on atmospheric corrosion, the marine atmosphere, and experimentation on marine atmospheric corrosion, the paper addresses key aspects such as the most significant corrosion products, the characteristics of the rust layers formed, and the mechanisms of steel corrosion in marine atmospheres. Special attention is then paid to important matters such as coastal-industrial atmospheres and long-term behaviour of carbon steel exposed to marine atmospheres. The work ends with a section dedicated to issues pending, noting a series of questions in relation with which greater research efforts would seem to be necessary.

Marine Atmospheric Corrosion of Carbon Steel: A Review

Science.gov (United States)

Alcántara, Jenifer; de la Fuente, Daniel; Chico, Belén; Simancas, Joaquín; Díaz, Iván; Morcillo, Manuel

2017-01-01

The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter’s great importance to human society. About half of the world’s population lives in coastal regions and the industrialisation of developing countries tends to concentrate production plants close to the sea. Until the start of the 21st century, research on the basic mechanisms of rust formation in Cl−-rich atmospheres was limited to just a small number of studies. However, in recent years, scientific understanding of marine atmospheric corrosion has advanced greatly, and in the authors’ opinion a sufficient body of knowledge has been built up in published scientific papers to warrant an up-to-date review of the current state-of-the-art and to assess what issues still need to be addressed. That is the purpose of the present review. After a preliminary section devoted to basic concepts on atmospheric corrosion, the marine atmosphere, and experimentation on marine atmospheric corrosion, the paper addresses key aspects such as the most significant corrosion products, the characteristics of the rust layers formed, and the mechanisms of steel corrosion in marine atmospheres. Special attention is then paid to important matters such as coastal-industrial atmospheres and long-term behaviour of carbon steel exposed to marine atmospheres. The work ends with a section dedicated to issues pending, noting a series of questions in relation with which greater research efforts would seem to be necessary. PMID:28772766

Evaluation of Iron Nickel Oxide Nanopowder as Corrosion Inhibitor: Effect of Metallic Cations on Carbon Steel in Aqueous NaCl

Energy Technology Data Exchange (ETDEWEB)

Chaudhry, A. U.; Mishra, Brajendra [Colorado School of Mines, Denver (United States); Mittal, Vikas [The Petroleum Institute, Abu Dhabi (United Arab Emirates)

2016-01-15

The aim of this study was to evaluate the use of iron-nickel oxide (Fe{sub 2}O{sub 3}.NiO) nanopowder (FeNi) as an anti-corrosion pigment for a different application. The corrosion protection ability and the mechanism involved was determined using aqueous solution of FeNi prepared in a corrosive solution containing 3.5 wt.% NaCl. Anti-corrosion abilities of aqueous solution were determined using electrochemical impedance spectroscopy (EIS) on line pipe steel (API 5L X-80). The protection mechanism involved the adsorption of metallic cations on the steel surface forming a protective film. Analysis of EIS spectra revealed that corrosion inhibition occurred at low concentration, whereas higher concentration of aqueous solution produced induction behavior.

Pitting growth rate in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1995-01-01

Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of below-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5% of the established limit) at a temperature of 50 C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured one each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

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.

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

OpenAIRE

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

2011-01-01

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

Mechanism of pitting corrosion prevention by nitrite in carbon steel exposed to dilute salt solutions. 1998 annual progress report

International Nuclear Information System (INIS)

Zapp, P.E.; Zee, J. van.

1998-01-01

'The overall goal of this project is to develop a fundamental understanding of the role of nitrite in preventing the breakdown of protective oxide(s) on carbon steel and the onset of pitting. Pitting corrosion of carbon steel exposed to dilute alkaline salt solutions can be induced by nitrate, sulfate, and chloride ions and is prevented by sufficient concentration of nitrite. A significant example of this material/electrolyte system is the storage and processing of DOE''s high-level radioactive liquid waste in carbon steel tanks. Added nitrite in the waste has a considerable downstream impact on the immobilization of the waste in a stable glass form. Waste tank integrity and glass production efficiency may benefit from the fundamental understanding of nitrite''s role in preventing pitting. This report summarizes progress after approximately six months of effort in this three-year EMSP project. Initial experimental and theoretical work has focused on the electrochemical behavior of carbon steel in simplified non-radioactive solutions that simulate complex dilute radioactive waste solutions. These solutions contain corrosion-inducing species such as nitrate and chloride and the corrosion-inhibiting nitrite at moderately alkaline pHs. The electrochemical behavior of interest here is that of the open-circuit potential of the steel specimen at equilibrium in the experimental electrolyte and the measures of the steel''s passivity and passivity breakdown.'

Long-term progress prediction for the carbon steel corrosion in diluted artificial seawater with and without zinc / sodium carbonate mixed phosphate

International Nuclear Information System (INIS)

Fujii, Kazumi; Ishioka, Shinichi; Iwanami, Masaru; Kaneko, Tetsuji; Tanaka, Norihiko; Kawaharada, Yoshiyuki; Yokoyama, Yutaka; Umehara, Ryuji; Kato, Chiaki; Ueno, Fumiyoshi; Fukaya, Yuichi; Kumaga, Katsuhiko

2017-01-01

The Fukushima Daiichi Nuclear Power Plants (1F) were damaged by an unprecedented severe accident in the great east Japan earthquake on 11th, March, 2011, and seawater and fresh water were injected as an emergency countermeasure for the core cooling. The primary containment vessels (PCVs), made of carbon steel, were exposed to seawater and fresh water, and have had the possibility of corrosion. The PCVs of 1F are the most important equipment for the core cooling and removal of the fuel debris, the structural integrity of the PCV must be maintained until decommissioning. Therefore, evaluation of PCV carbon steel corrosion behavior is important, as well as evaluation of corrosion inhibitors as one of the corrosion protection methods. In this study, long-term immersion corrosion tests for up to 10000 hours were performed in diluted artificial seawater simulating 1F with and without zinc / sodium carbonate mixed phosphate. Based on the long-term immersion corrosion test results, diagnosis method of the reduction in plate thickness of the nuclear vessel was examined. The validity of the existing corrosion progress models following parabolic rate law was confirmed. The corrosion progress models were also applicable to the corrosion inhibited condition adding zinc / sodium carbonate mixed phosphate. It was found that the corrosion rate of carbon steel drastically fell down by adding this corrosion inhibitor. (author)

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

Science.gov (United States)

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

2018-01-01

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

Modeling the wire-EDM process parameters for EN-8 carbon steel ...

African Journals Online (AJOL)

Modeling the wire-EDM process parameters for EN-8 carbon steel using .... The neural networks has been developed with the help of MATLAB 8.1 (R13) package .... Now, Simulation and Prediction will be performed using the trained network.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-05-01

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

Influence of preheating on API 5L-X80 pipeline joint welding with self shielded flux-cored wire; Influencia del precalentamiento en las propiedades de uniones soldadas de acero API 5L-X80 soldadas con alambre tubular autoprotegido

Energy Technology Data Exchange (ETDEWEB)

Cooper, R.; Silva, J. H. F.; Trevisan, R. E.

2004-07-01

The present work refers to the characterization of API 5L-X80 pipeline joints welded with self-shielded flux cored wire. This process was evaluated under preheating conditions, with an uniform and steady heat input. All joints were welded in flat position (1G), with the pipe turning and the torch still. Tube dimensions were 762 mm in external diameter and 16 mm in thickness. Welds were applied on single V-groove, with six weld beads, along with three levels of preheating temperatures (room temperature, 100 degree centigree, 160 degree centigree). These temperatures were maintained as inter pass temperature. The filler metal E71T8-K6 with mechanical properties different from parent metal was used in under matched conditions. The weld characterization is presented according to the mechanical test results of tensile strength, hardness and impact test. The mechanical tests were conducted according to API 1104, AWS and ASTM standards. API 1104 and API 51 were used as screening criteria. According to the results obtained, it was possible to remark that it is appropriate to weld API 5L-X80 steel ducts with Self-shielded Flux Cored wires, in conformance to the API standards and no preheat temperature is necessary. (Author) 22 refs.

Outdoor corrosion of zinc coated carbon steel, determined by thin layer activation

International Nuclear Information System (INIS)

Agostini, M.L.; Laguzzi, G.; De Cristofaro, N.; Stroosnijder, M.F.

2001-01-01

Thin Layer Activation was applied in the frame of a European programme addressed to the evaluation of the corrosion the behaviour of different steels. This included outdoor exposure of zinc coated carbon steel in a rural-marine climatic environment, for a period of several months. The zinc layer of specimens was 10 micrometers thick. For the TLA studies 65Zn radio nuclides were produced along the full depth of the coating, by a cyclotron accelerated deuteron beam. For quantification of the material release, activity versus depth was determined using different thickness of Zn coatings on top the carbon steel. After exposure corrosion product were removed from the surface using a pickling solution and the residual activity was determined by gamma spectrometry. The high sensitivity of the method allowed the evaluation of relatively small thickness losses (i.e. 1.2 micrometer). Thickness loss results, obtained by the TLA method, were compared with those arising from the Atomic Absorption analysis of zinc detected in the pickling solutions. A good agreement was observed between the different methods

Corrosion resistance and characterization of metallic coatings deposited by thermal spray on carbon steel

International Nuclear Information System (INIS)

Sá Brito, V.R.S.; Bastos, I.N.; Costa, H.R.M.

2012-01-01

Highlights: ► Five combinations of metallic coatings and intermediate bonds were deposited on carbon steels. ► High strength was reached in adhesion tests. ► Epoxy sealing of coatings improves corrosion resistance. -- Abstract: Carbon steels are not resistant to corrosion and several methods are used in surface engineering to protect them from aggressive environments such as marine. The main objective of this work is the evaluation of mechanical and metallurgical properties of five metallic coatings produced by thermal spray on carbon steel. Five chemical compositions were tested in order to give a large panel of possibility. Coatings were characterized by several methods to result in a screening of their performance. At first, the assessment of microstructural morphology by optical microscopy (OM) and by scanning electron microscopy (SEM) was made. OM and SEM results showed uniformity of deposited layer, low amount of oxides and porosity. The physical properties of coatings were also evaluated by microhardness measurement, adhesion and porosity quantification. The corrosion resistance was analyzed in salt spray and electrochemical polarization tests. In the polarization test, as well as in the salt spray, all sealed conditions presented low corrosion. A new intermediate 78.3Ni20Cr1.4Si0.3Fe alloy was studied in order to reduce pores and microcracks that are frequently found in ordinary 95Ni5Al alloy. Based on the performed characterizations, the findings suggested that the FeCrCo deposition, with an epoxy sealing, is suitable to be used as an efficient coating of carbon steel in aggressive marine environments.

DIRAC RESTful API

International Nuclear Information System (INIS)

Casajus Ramo, A; Graciani Diaz, R; Tsaregorodtsev, A

2012-01-01

The DIRAC framework for distributed computing has been designed as a flexible and modular solution that can be adapted to the requirements of any community. Users interact with DIRAC via command line, using the web portal or accessing resources via the DIRAC python API. The current DIRAC API requires users to use a python version valid for DIRAC. Some communities have developed their own software solutions for handling their specific workload, and would like to use DIRAC as their back-end to access distributed computing resources easily. Many of these solutions are not coded in python or depend on a specific python version. To solve this gap DIRAC provides a new language agnostic API that any software solution can use. This new API has been designed following the RESTful principles. Any language with libraries to issue standard HTTP queries may use it. GSI proxies can still be used to authenticate against the API services. However GSI proxies are not a widely adopted standard. The new DIRAC API also allows clients to use OAuth for delegating the user credentials to a third party solution. These delegated credentials allow the third party software to query to DIRAC on behalf of the users. This new API will further expand the possibilities communities have to integrate DIRAC into their distributed computing models.

Assembling of carbon nanotubes film responding to significant reduction wear and friction on steel surface

Science.gov (United States)

Zhang, Bin; Xue, Yong; Qiang, Li; Gao, Kaixong; Liu, Qiao; Yang, Baoping; Liang, Aiming; Zhang, Junyan

2017-11-01

Friction properties of carbon nanotubes have been widely studied and reported, however, the friction properties of carbon nanotubes related on state of itself. It is showing superlubricity under nanoscale, but indicates high shear adhesion as aligned carbon nanotube film. However, friction properties under high load (which is commonly in industry) of carbon nanotube films are seldom reported. In this paper, carbon nanotube films, via mechanical rubbing method, were obtained and its tribology properties were investigated at high load of 5 to 15 N. Though different couple pairs were employed, the friction coefficients of carbon nanotube films are nearly the same. Compared with bare stainless steel, friction coefficients and wear rates under carbon nanotube films lubrication reduced to, at least, 1/5 and 1/(4.3-14.5), respectively. Friction test as well as structure study were carried out to reveal the mechanism of the significant reduction wear and friction on steel surface. One can conclude that sliding and densifying of carbon nanotubes at sliding interface contribute to the sufficient decrease of friction coefficients and wear rates.

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

International Nuclear Information System (INIS)

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

1982-01-01

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

The development of RFT technique for carbon steel tubes in balance-of-plant heat exchangers

International Nuclear Information System (INIS)

Kim, Chang Soo; Kim, Han Jong; Moon, Yong Sick; Kim, Jae Dong; Kim, Wang Bae; Nam, Min Woo

2005-01-01

The NDT method of carbon steel tubes is applied RFT technique. As other NDT methods, It is surprising that RFT has been rapidly developed over the past decade. These improvements have resulted in multi-frequency system, dual driver probes and development of analysis technique. Also these improvements give some profit to power plants as well as general industry. Therefore, the purpose of this study is to improve the reliability of RFT technique for carbon steel tubes. To uplift RFT technique, probes, calibration standards and specimen was developed.

A coupled carbonation-rust formation mechanical damage model for steel corrosion in reinforced concrete

International Nuclear Information System (INIS)

Nguyen, Huyen; Bary, B.; L'Hostis, Valerie; DeLarrard, T.

2014-01-01

This paper aims at presenting a strategy to simulate the corrosion of steel reinforcement due to carbonation of concrete in atmospheric environment. We propose a model coupling drying, carbonation, diffusion of oxygen, formation of rust and mechanics to describe these phenomena. The rust layer is assumed to be composed of two sub-layers with different elastic modulus. An unstable layer with a low modulus (from 0.1 to 5 GPa) is located next to the transformed medium, and another more stable one with a higher modulus (from 100 to 150 GPa) at the interface with steel reinforcement. This model is applied to a numerical meso-structure composed of 4 phases: mortar matrix, randomly distributed aggregates, steel rebar and rust layers to underline the effect of aggregates on damage initiation and corresponding crack pattern of concrete cover. (authors)

Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki [and others

1997-04-01

The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program.

Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410

International Nuclear Information System (INIS)

Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki

1997-01-01

The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Depositing Nickel-based Hardfacing to Join Carbon Steel and Cast Iron

Directory of Open Access Journals (Sweden)

Tomás Fernández-Columbié

2016-10-01

Full Text Available The objective of this investigation is to determine the micro-structural behavior of a joint between cast iron and carbon steel by depositing a nickel-based substrate in the carbon steel. The filler was added through Shielded Metal Arc Welding using Castec 3099 (UTP 8 electrodes while the base materials were joined through Gas Tungsten Arc Welding with ER 70S – A1 bare electrodes. The Schaeffler diagram was used to analyze the chemical composition of the resulting weld beads. The results of the analysis performed on the welded area and the heat influence zone indicated the formation of acicular structures near the welded line when Castec 3099 electrodes are used and the formation of skeletal ferrite on the heat influence zone during the application of this welding process. An austenitic mixture is formed when ER 70S – A1 electrodes are used.

Enhanced wear resistance of production tools and steel samples by implantation of nitrogen and carbon ions

International Nuclear Information System (INIS)

Mikkelsen, N.J.; Straede, C.A.

1992-01-01

In recent years ion implantation has become a feasible technique for obtaining improved wear resistance of production tools. However, basic knowledge of how and in which cases ion implantation is working at its best is still needed. The present paper discusses structural and tribological investigations of carbon and nitrogen implanted steels. The nitrogen data were obtained mainly from field tests and the investigation of carbon implantations took place mainly in the laboratory. A study was made of how the tribological behaviour of implanted steels changes with different implantation parameters. The tribological laboratory investigations were carried out using pin-on-disc equipment under controlled test conditions, and deal with high dose carbon implantation (approximately (1-2)x10 18 ions cm -2 ). The wear resistance of steels was enhanced dramatically, by up to several orders of magnitude. The field test results cover a broad range of ion implanted production tools, which showed a marked improvement in wear resistance. Nitrogen implanted tools are also compared with carbon and titanium implanted tools. (orig.)

The anaerobic corrosion of carbon steel and cast iron in artificial groundwaters

Energy Technology Data Exchange (ETDEWEB)

Smart, N.R. [AEA Technology plc, Culham Science Centre (United Kingdom); Blackwood, D.J. [National Univ. of Singapore (Singapore); Werme, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

2001-07-01

In Sweden, high level radioactive waste will be disposed of in a canister with a copper outer and a cast iron or carbon steel inner. If the iron insert comes into contact with anoxic geological water, anaerobic corrosion leading to the generation of hydrogen will occur. This paper presents a study of the anaerobic corrosion of carbon steel and cast iron in artificial Swedish granitic groundwaters. Electrochemical methods and gas collection techniques were used to assess the mechanisms and rates of corrosion and the associated hydrogen gas production over a range of conditions. The corrosion rate is high initially but is anodically limited by the slow formation of a duplex magnetite film. The effects of key environmental parameters such as temperature and ionic strength on the anaerobic corrosion rate are discussed.

The anaerobic corrosion of carbon steel and cast iron in artificial groundwaters

International Nuclear Information System (INIS)

Smart, N.R.; Blackwood, D.J.; Werme, L.

2001-07-01

In Sweden, high level radioactive waste will be disposed of in a canister with a copper outer and a cast iron or carbon steel inner. If the iron insert comes into contact with anoxic geological water, anaerobic corrosion leading to the generation of hydrogen will occur. This paper presents a study of the anaerobic corrosion of carbon steel and cast iron in artificial Swedish granitic groundwaters. Electrochemical methods and gas collection techniques were used to assess the mechanisms and rates of corrosion and the associated hydrogen gas production over a range of conditions. The corrosion rate is high initially but is anodically limited by the slow formation of a duplex magnetite film. The effects of key environmental parameters such as temperature and ionic strength on the anaerobic corrosion rate are discussed

Marine Atmospheric Corrosion of Carbon Steel: A Review

OpenAIRE

Alc?ntara, Jenifer; de la Fuente, Daniel; Chico, Bel?n; Simancas, Joaqu?n; D?az, Iv?n; Morcillo, Manuel

2017-01-01

The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter’s great importance to human society. About half of the world’s population lives in coastal regions and the industrialisation of developing countries tends to concentrate production pl...

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.

Android quick APIs reference

CERN Document Server

Cinar, Onur

2015-01-01

The Android Quick APIs Reference is a condensed code and APIs reference for the new Google Android 5.0 SDK. It presents the essential Android APIs in a well-organized format that can be used as a handy reference. You won't find any technical jargon, bloated samples, drawn out history lessons, or witty stories in this book. What you will find is a software development kit and APIs reference that is concise, to the point and highly accessible. The book is packed with useful information and is a must-have for any mobile or Android app developer or programmer. In the Android Quick APIs Refe

Corrosion of carbon steel in clay environments relevant to radioactive waste geological disposals, Mont Terri rock laboratory (Switzerland)

Energy Technology Data Exchange (ETDEWEB)

Necib, S. [Agence Nationale pour la Gestion des Déchets Radioactifs ANDRA, Meuse Haute-Marne, Center RD 960, Bure (France); Diomidis, N. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Keech, P. [Nuclear Waste Management Organisation NWMO, Toronto (Canada); Nakayama, M. [Japan Atomic Energy Agency JAEA, Horonobe-Cho (Japan)

2017-04-15

Carbon steel is widely considered as a candidate material for the construction of spent fuel and high-level waste disposal canisters. In order to investigate corrosion processes representative of the long term evolution of deep geological repositories, two in situ experiments are being conducted in the Mont Terri rock laboratory. The iron corrosion (IC) experiment, aims to measure the evolution of the instantaneous corrosion rate of carbon steel in contact with Opalinus Clay as a function of time, by using electrochemical impedance spectroscopy measurements. The Iron Corrosion in Bentonite (IC-A) experiment intends to determine the evolution of the average corrosion rate of carbon steel in contact with bentonite of different densities, by using gravimetric and surface analysis measurements, post exposure. Both experiments investigate the effect of microbial activity on corrosion. In the IC experiment, carbon steel showed a gradual decrease of the corrosion rate over a period of 7 years, which is consistent with the ongoing formation of protective corrosion products. Corrosion product layers composed of magnetite, mackinawite, hydroxychloride and siderite with some traces of oxidising species such as goethite were identified on the steel surface. Microbial investigations revealed thermophilic bacteria (sulphate and thiosulphate reducing bacteria) at the metal surface in low concentrations. In the IC-A experiment, carbon steel samples in direct contact with bentonite exhibited corrosion rates in the range of 2 µm/year after 20 months of exposure, in agreement with measurements in absence of microbes. Microstructural and chemical characterisation of the samples identified a complex corrosion product consisting mainly of magnetite. Microbial investigations confirmed the limited viability of microbes in highly compacted bentonite. (authors)

Hot corrosion behaviour of austenitic steel-303 in molten chloride and carbonate salts

International Nuclear Information System (INIS)

Mohd Misbahul Amin; Shamsul Baharin Jamaludin; Che Mohd Ruzaidi Ghazali; Khairel Rafezi Ahmad

2007-01-01

The investigations are presented for the hot corrosion behaviors of Austenitic Steel-303, under influence of the molten chloride and carbonate salts viz KCl and K 2 CO 3 , oxidised at 1123 K for the period of 60 hour at atmospheric condition. The oxidation kinetic are effect of molten chloride and carbonate salts deposition on the oxidation rate were determined. The susceptibility to suffer a deleterious attack on the alloy by internal corrosion increases with increasing the time. In general, the corrosion resistance austenitic steel-303 in molten carbonate salts is much higher than chloride melt, being an active oxidizing agent providing oxygen during fluxing reaction. However, due to profuse evolution of CO/ CO 2 heavy mass losses are observed during corrosion and scales are porous. The test included mass change monitoring and surface layers were examined by means of scanning electron microscopy (SEM) studies. (author)

Corrosion control of carbon steel using inhibitor of banana peel extract in acid diluted solutions

Science.gov (United States)

Komalasari; Utami, S. P.; Fermi, M. I.; Aziz, Y.; Irianti, R. S.

2018-04-01

Issues of corrosion happened in pipes, it was used as fluid transportation in the chemical industry. Corrosion cannot be preventing, however it could be controlled or blocked. Inhibitor addition is one of the method to control the corrosion inside the pipe. Corrosion inhibitors consisted of inorganic and organic compound inhibitors. Organic inhibitor is composed from synthetic and natural material. This study focused to evaluate the inhibition’s efficiency from banana peel to carbon steel in different concentration of inhibitor and immersing time in acid solution variation. The research employed inhibitor concentration of 0 gram/liter, 2 gram/liter, 4 gram/liter and 6 gram/liter, immersed time of carbon steel for 2, 4, 6, 8 and 10 hours. It was immersed in chloride acid solution of 0.5 M and 1.5 M. Carbon Steel AISI 4041 was used as specimen steel. Results were analyzed using corrosion rate evaluation for each specimens and inhibitor efficiencies determination. It was found that the specimen without inhibitor yielded fast corrosion rate in long immersing time and high concentration of HCl. However, the specimens with inhibitor gave lowest corrosion rate which was 78.59% for 6 gram/litre and 10 hours in 0.5 M HCl.

Evaluation of Flow Accelerated Corrosion of Carbon Steel with Rotating Cylinder

International Nuclear Information System (INIS)

Park, Tae Jun; Lee, Eun Hee; Kim, Kyung Mo; Kim, Hong Pyo

2012-01-01

Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. Rotating cylinder FAC test facility was designed and fabricated and then performance of the facility was evaluated. The facility is very simple in design and economic in fabrication and can be used in material and chemistry screening test. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO), and temperature. Fluid velocity is controlled with rotating speed of the cylinder with a test specimen. FAC test of SA106 Gr. B carbon steel under 4 m/s flow velocity was performed with the rotating cylinder at DO concentration of less than 1 ppb and of 1.3 ppm. Also a corrosion test of the carbon steel at static condition, that is at zero fluid velocity, of test specimen and solution was performed at pH from 8 to 10 for comparison with the FAC data. For corrosion test in static condition, the amount of non adherent corrosion product was almost constant at pH ranging from 8 to 10. But adherent corrosion product decreased with increasing pH. This trend is consistent with decrease of Fe solubility with an increase in pH. For FAC test with rotating cylinder FAC test facility, the amount of non adherent corrosion product was also almost same for both DO concentrations. The rotating cylinder FAC test facility will be further improved by redesigning rotating cylinder and FAC specimen geometry for future work

Influence of preheating on API 5L-X80 pipeline joint welding with self shielded flux-cored wire

International Nuclear Information System (INIS)

Cooper, R.; Silva, J. H. F.; Trevisan, R. E.

2004-01-01

The present work refers to the characterization of API 5L-X80 pipeline joints welded with self-shielded flux cored wire. This process was evaluated under preheating conditions, with an uniform and steady heat input. All joints were welded in flat position (1G), with the pipe turning and the torch still. Tube dimensions were 762 mm in external diameter and 16 mm in thickness. Welds were applied on single V-groove, with six weld beads, along with three levels of preheating temperatures (room temperature, 100 degree centigree, 160 degree centigree). These temperatures were maintained as inter pass temperature. The filler metal E71T8-K6 with mechanical properties different from parent metal was used in under matched conditions. The weld characterization is presented according to the mechanical test results of tensile strength, hardness and impact test. The mechanical tests were conducted according to API 1104, AWS and ASTM standards. API 1104 and API 51 were used as screening criteria. According to the results obtained, it was possible to remark that it is appropriate to weld API 5L-X80 steel ducts with Self-shielded Flux Cored wires, in conformance to the API standards and no preheat temperature is necessary. (Author) 22 refs

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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

Pitting growth rate in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1996-06-01

Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion tests are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of out-of-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5 per cent of the established limit) at a temperature of 50 degrees C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured on each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum expected pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

A serviceability approach for carbon steel piping to intermittent high temperatures

International Nuclear Information System (INIS)

Ratiu, M.D.; Moisidis, N.T.

1996-01-01

Carbon steel piping (e.g., ASME SA-106, SA-53), is installed in many industrial applications (i.e. diesel generator at NPP) where the internal gas flow subjects the piping to successive short time exposures at elevated temperatures up to 1,100 F. A typical design of this piping without consideration for creep-fatigue cumulative damage is at least incomplete if not inappropriate. Also, a design for creep-fatigue, usually employed for long-term exposure to elevated temperatures, would be too conservative and will impose replacement of the carbon steel piping with heat-resistant CrMo steel piping. The existing ASME Standard procedures do not explicitly provide acceptance criteria for the design qualification to withstand these intermittent exposures to elevated temperatures. The serviceability qualification proposed is based on the evaluation of equivalent full temperature cycles which are presumed/expected to be experienced by the exhaust piping during the design operating life of the diesel engine. The proposed serviceability analysis consists of: (a) determination of the permissible stress at elevated temperatures, and (b) estimation of creep-fatigue damage for the total expected cycles of elevated temperature exposures following the procedure provided in ASME Code Cases N-253-6 and N-47-28

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).

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

International Nuclear Information System (INIS)

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

2013-01-01

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

An assessment of carbon steel overpacks for radioactive waste disposal

International Nuclear Information System (INIS)

Marsh, G.P.; Bland, I.D.; Taylor, K.J.; Sharland, S.; Tasker, P.

1986-01-01

The report summarizes the results obtained at Harwell in the second phase of a project evaluating the corrosion behaviour of high-level waste overpacks in geological disposal. It has concentrated on the use of carbon steel in granitic and argillaceous environments, and has aimed at estimating the corrosion allowance required to achieve a 1000-year overpack life. Experimental and mathematical modelling studies have indicated that 200 mm of steel should be more than sufficient to prevent overpack penetration by general or localized corrosion. A theoretical assessment of the possible effects of micro-organisms on overpack corrosion has concluded that such species are likely to be found in repositories, but that only a fraction of their population should be corrosive towards carbon steel. Making the pessimistic assumption that all organic carbon in a 500 mm bentonite backfill is utilized by corrosive sulphate reducing bacteria, it has been estimated that this will result in an additional metal loss of 13 mm. One form of corrosion which cannot be dealt with by the corrosion allowance approach is stress corrosion cracking, since even at the lowest reported propagation rates, a metal thickness exceeding 3 m would be penetrated in 1000 years. It has been concluded that the possibility of stress corrosion cannot be dismissed, but, because the process requires a certain minimum stress level before it can occur, it should be possible to avoid the problem by giving the overpacks a stress relief heat treatment. Tests in a model environment have shown that a heat treatment designed to reduce fabrication stresses to 50% of the yield strengh should be sufficient to prevent cracking. It is recommended that this conclusion be substantiated by scaled-up experiments with model overpacks. The report draws further attention to degradation by hydrogen embrittlement

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

Science.gov (United States)

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

2017-07-01

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

Study of texture and microstructure evaluation of steel API 5L X70 under various thermomechanical cycles

Energy Technology Data Exchange (ETDEWEB)

Masoumi, Mohammad, E-mail: Mohammad@alu.ufc.br; Herculano, Luis Flavio Gaspar; Ferreira Gomes de Abreu, Hamilton

2015-07-15

This work studies the influence of different thermomechanical paths on the microstructure and crystallographic texture across the thickness of API 5L X70 pipeline steel manufactured via hot rolling using X-ray diffraction (XRD), scanning electron microscope (SEM), and electron backscattered diffraction (EBSD). The starting materials were controlled hot-rolled at 1000 °C to 44% and 67% reductions and subsequently heat treated with such processes as annealing, water quenching and quench tempering at three different temperatures to evaluate the microstructure and crystallographic texture changes across the thickness. The banded ferrite-pearlite microstructure of the initial material was changed to acicular ferrite, quasi-polygonal ferrite, granular bainite, martensite and retained austenite via different heat treatments. Moreover, different thermomechanical paths induced crystallographic texture variations across the thickness, e.g., {112}//ND, {111}//ND (γ fibre), and {011}//ND fibres dominated on the surface plane in contact with the rolls, whereas {001}//ND and particularly the (001)[1 1 0] texture component developed in the centre plane on which shear deformation has a zero value in this region. In this study, a simple interpretation of texture evolution was analyzed by comparison with the orientation changes that occurred during different rolling schedules and post-treatment processes.

Characterizing the effect of carbon steel exposure in sulfide containing solutions to microbially induced corrosion

Energy Technology Data Exchange (ETDEWEB)

Sherar, B.W.A. [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada); Power, I.M. [Department of Earth Sciences, University of Western Ontario, London, ON, N6A 5B7 (Canada); Keech, P.G.; Mitlin, S. [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada); Southam, G. [Department of Earth Sciences, University of Western Ontario, London, ON, N6A 5B7 (Canada); Shoesmith, D.W., E-mail: dwshoesm@uwo.c [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada)

2011-03-15

Research highlights: Compares inorganic sulfide and sulfate reducing bacteria (SRB) on steel corrosion. Mackinawite was the dominant iron sulfide phase. SRBs can form nanowires, presumably grown to acquire energy. - Abstract: This article compares the electrochemical effects induced by inorganic sulfide and sulfate reducing bacteria on the corrosion of carbon steel - a subject of concern for pipelines. Biological microcosms, containing varying concentrations of bioorganic content, were studied to investigate changes to the morphology of biofilms and corrosion product deposits. Raman analysis indicated mackinawite (FeS{sub 1-x}) was the dominant iron sulfide phase grown both abiotically and biotically. A fascinating feature of biological media, void of an organic electron donor, was the formation of putative nanowires that may be grown to acquire energy from carbon steel by promoting the measured cathodic reaction.

Analysis of corrosion products of carbon steel in wet bentonite

International Nuclear Information System (INIS)

Osada, K.; Nagano, T.; Kozai, N.; Nakashima, S.; Nakayama, S.; Muraoka, S.

1991-01-01

The following conclusions were obtained; (1) At 40degC, the average corrosion rate of SS41 carbon steel in wet bentonite was 0.025 mm/y. This is smaller than the value of 0.042 mm/y obtained in pure water at 40degC. However, at 95degC, the corrosion rate of SS41 carbon steel in wet bentonite was 0.27 mm/y, which is much larger than that in pure water at 95degC. (2) At 95degC, γ-FeO(OH) (lepidocrocite) was formed only in wet bentonite, and it was absent in pure water. Evaporation of moisture resulted in the formation of partial covering of bentonite, which promoted local corrosion. Consequently, γ-FeO(OH) was considered to be formed. (3) In wet bentonite at 95degC, α-Fe 2 O 3 (hematite) can be identified by means of colorimetry. The color of corrosion products is orangish, indicating the contribution of α-Fe 2 O 3 in iron hydroxides. (author)

Combined geochemical and electrochemical methodology to quantify corrosion of carbon steel by bacterial activity

International Nuclear Information System (INIS)

Schutz, Marta K.; Moreira, Rebeca; Tribollet, Bernard; Vivier, Vincent; Bildstein, Olivier; Lartigue, Jean-Eric; Libert, Marie; Schlegel, Michel L.

2014-01-01

The availability of respiratory substrates, such as H 2 and Fe(II,III) solid corrosion products within nuclear waste repository, will sustain the activities of hydrogen-oxidizing bacteria (HOB) and iron-reducing bacteria (IRB). This may have a direct effect on the rate of carbon steel corrosion. This study investigates the effects of Shewanella oneidensis (an HOB and IRB model organism) on the corrosion rate by looking at carbon steel dissolution in the presence of H 2 as the sole electron donor. Bacterial effect is evaluated by means of geochemical and electrochemical techniques. Both showed that the corrosion rate is enhanced by a factor of 2-3 in the presence of bacteria. The geochemical experiments indicated that the composition and crystallinity of the solid corrosion products (magnetite and vivianite) are modified by bacteria. Moreover, the electrochemical experiments evidenced that the bacterial activity can be stimulated when H 2 is generated in a small confinement volume. In this case, a higher corrosion rate and mineralization (vivianite) on the carbon steel surface were observed. The results suggest that the mechanism likely to influence the corrosion rate is the bioreduction of Fe(III) from magnetite coupled to the H 2 oxidation. (authors)

INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

OpenAIRE

S. Chihi; N. Gherraf; B. Alabed; S. Hameurlain

2009-01-01

The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization result...

BEHAVIOUR CORROSION OF API 5L X70 AND API 5L X80 STEELS IN A CO2 MEDIUM BY SURFACE ANALYSIS AND ELECTROCHEMICAL TECHNIQUES

OpenAIRE

MILAGROS MABEL GUILLEN NUNEZ

2006-01-01

A seleção de materiais para o transporte de óleo e gás não é feita pela sua resistência à corrosão, mas sim pelas suas boas propriedades mecânicas, facilidade de fabricação e baixos custos. Devido às taxas de perda de material, causado pela corrosão interna, existe necessidade em se conhecer o comportamento dos aços de mais alta resistência, utilizados especialmente em gasodutos e oleodutos tais como API 5L X70 e API 5L X80. Um dos elementos responsáveis ...

Effect of magnesium ions on the initial oxidation stages of carbon steel

International Nuclear Information System (INIS)

Subramanian, H.; Subramanian, Veena; Rangarajan, S.; Narasimhan, S.V.; Velmurugan, S.

2012-09-01

Metal Ion Passivation (MIP) is a technique in which passivating ions get into the oxide of structural materials and modifies the oxide in such a way as to reduce the corrosion and corrosion release rates. Magnesium ions are found to be efficient in passivating carbon steel. This study is an attempt to understand the role of magnesium ions during the early stage of film growth on carbon steel. The study reveals that in the presence of Mg, the initial oxide film formed by the application of potential had a different electrochemical property. The microstructure of the parent alloy of steel also interacted differently with Mg during the film formation. The ferrite film was grown on carbon steel by applying 0.1 V (vs SCE) in borate buffer (pH=9, 85 deg. C). The formation and coverage of film on the surface was ascertained by measuring the steady state current density as a function of time. The steady state current density was achieved faster when Mg was present in the solution. The thin film formed was characterized by both by electrochemical impedance spectroscopy and atomic force microscopy. The formation of a passive film (at 0.1 V vs SCE) was evident in both with and without Mg cases, with total impedance of the system increasing by an order of magnitude compared to the film formed at OCP (∼ - 0.825 V vs SCE). The data was fitted to an equivalent circuit representing a metal covered with a porous film. The fit parameters were significantly different for Mg containing system and the charge transfer resistance at oxide/solution interface was observed to be two times higher. The capacitance of the film was also higher in presence of Mg indicating a thinner film. The thin films on carbon steel were characterized by AFM in semi contact mode. The surfaces were found to be covered with fine oxide. Two morphologically different regions could be identified on the surface and they were assigned as pearlite and ferrite regions. One of the most notable observations was the

Review of CO2 Reduction Technologies using Mineral Carbonation of Iron and Steel Making Slag in Malaysia

Science.gov (United States)

Norhana Selamat, Siti; Nor, Nik Hisyamudin Muhd; Rashid, Muhammad Hanif Abdul; Fauzi Ahmad, Mohd; Mohamad, Fariza; Ismail, Al Emran; Fahrul Hassan, Mohd; Turan, Faiz Mohd; Zain, Mohd Zamzuri Mohd; Abu Bakar, Elmi; Seiji, Yokoyama

2017-10-01

Climate change, greenhouse gas effect, and global warming is envisioning to turn more awful and more terrible by year. Since the leading cause of global warming is uncontrolled CO2 in atmosphere. The amount of unused steel slag is expected to increment later on, steel industries is one of the mechanical industries that contribute the CO2 emission. That because this businesses deliver carbon in light of powers reductant and substantial volume of steel. The changes of atmosphere these day is truly developing concern and that make steel creator are confronted with test of discovering methods for bringing down CO2 emission. Malaysia is working decidedly in the diminishment of CO2 gas. There are a few techniques in decreasing the amount of CO2 in the air as underlined by the Intergovernmental Panel of Climate Change (IPCC), an organization under the United Country however CCS is an extremely encouraging innovation to moderate CO2 emission in air. Mineral carbonation is another technique to store carbon dioxide permanently, long term stability and vast capacity.

API 5L X80 PSL2 pipes manufactured by ERW process: TenarisConfab and USIMINAS development; Tubos API 5L X80 PSL2 processados por ERW: desenvolvimento TenarisConfab-Usiminas

Energy Technology Data Exchange (ETDEWEB)

Silva, Ronaldo C.; Roza, Juliana E.; Kojima, Sergio S. [TenarisConfab, Pindamonhangaba, SP (Brazil); Miranda, Lucio S.; Turani, Leonardo O. [USIMINAS, Ipatinga, MG (Brazil)

2005-07-01

The utilization of high strength steels can decrease, both, installation and operation costs of a new pipeline, since the increase of mechanical resistance can reduce the pipe wall thickness and, consequently, the weight of the pipe. For this purpose, the manufacture of electric resistance welding (ERW) pipes is recent, and it comes as an opportunity for gas pipelines, mainly onshore projects. As a function of their larger productivity, ERW pipes are more economically attractive than those produced by seamless and SAW processes. TenarisConfab and USIMINAS, through studies and investments in manufacturing processes, have been working to increase their skills, in order to supply ERW pipes in API 5L X80 PSL2 steel. The steel elaborated by USIMINAS is low C, high Mn, Nb, V and Ti microalloyed, and with additions of Cr and Mo, aiming to produce hot rolled coils with acicular microstructure, achieved as a combination between its chemical composition and higher cooling rates after hot rolling. The results in {phi}18''(457 mm) x 0,469''(11,91 mm) pipes are presented in this article. High toughness values reached at very low temperatures suggest that ERW API 5L X80 PSL2 pipes developed by TenarisConfab and USIMINAS may be an excellent option of choice for onshore projects that request pipes in diameters up to 20''(508 mm) and thickness up to 0,500'' (12,7 mm). (author)

Influence of Surface Roughness and Agitation on the Morphology of Magnetite Films Electrodeposited on Carbon Steel Substrates

Directory of Open Access Journals (Sweden)

Soon-Hyeok Jeon

2016-11-01

Full Text Available In this work, we investigated the effects of surface roughness and agitation on the morphology of magnetite films electrodeposited from alkaline Fe(III-triethanolamine (TEA solutions on carbon steel substrates. The surface roughness of the carbon steel substrates was maintained in the range of 1.64–0.06 μm by using mechanical grinding and polishing methods. The agitation speed was set at 0 and 900 rpm during the electrodeposition process. The particle size and surface roughness value of the magnetite films gradually decreased with decreasing substrate roughness. However, the influence of the substrate roughness on the thickness of the magnetite film was negligible. The morphology of the magnetite film fabricated at 900 rpm appeared to be highly faceted compared to that of the magnetite film produced at 0 rpm. The thickness and surface roughness of the magnetite film significantly increased with the agitation speed, which also significantly affected the electrodeposition efficiency. The effects of substrate surface roughness and agitation on the morphology of magnetite films electrodeposited on carbon steel substrates were also discussed. The obtained results provide critical information for the simulation of magnetite deposits on carbon steel pipes in the secondary systems of nuclear power plants.

Advanced API security securing APIs with OAuth 2.0, OpenID Connect, JWS, and JWE

CERN Document Server

Siriwardena, Prabath

2014-01-01

Advanced API Security is a complete reference to the next wave of challenges in enterprise security--securing public and private APIs. API adoption in both consumer and enterprises has gone beyond predictions. It has become the 'coolest' way of exposing business functionalities to the outside world. Both your public and private APIs, need to be protected, monitored and managed. Security is not an afterthought, but API security has evolved a lot in last five years. The growth of standards, out there, has been exponential. That's where AdvancedAPI Security comes in--to wade through the weeds

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.

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

International Nuclear Information System (INIS)

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

2014-01-01

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