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Sample records for 5l x70 steel

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

    OpenAIRE

    2014-01-01

    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 i...

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. Determination of acoustoelastic constant in API-5L-X70 welded pipes; Determinacao da constante acustoelastica de tubos API-5L-X70 com solda

    Energy Technology Data Exchange (ETDEWEB)

    Bittencourt, Marcelo de Siqueira Queiroz; Fonseca, Manoel Antonio da Costa [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Oliveira, Carlos Henrique Francisco de [PETROBRAS S.A., Rio de de Janeiro, RJ (Brazil)

    2008-07-01

    To preserve the environment and avoid financial losses resulting from leaks in the transport of natural oil and gas the industry is particularly concerned to ensure the structural integrity of their pipelines. Grounded pipes may be exposed to damages due to unstable soil movement, and in extreme cases, to failure. Then, techniques to assess stress in pipelines are of central importance. The ultrasonic birefringence technique is an efficient method to measure residual stress. It is based on the changing velocity of the shear wave when it crosses a material under stress; this phenomenon is known as acoustoelasticity. The knowledge of the parameter called acoustoelastic constant is necessary to measure stress using this technique. By the mechanical conformation in the manufacture of welded tubes, from rolled plates, different anisotropy degrees are showed around the cross section of these tubes. In this paper it was studied the acoustoelastic constant for the API-5L-X70 steel pipes, with different thicknesses, diameters and manufacturing processes so as to be able to use this technique to stress measurement in pipelines. (author)

  7. Effect of Environmental Factors on Electrochemical Behavior of X70 Pipeline Steel in Simulated Soil Solution

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; LI Xiao-gang; DU Cui-wei

    2009-01-01

    Potentiodynamic polarization measurement was used to investigate the effects of temperature, dissolved ox-ygen concentration and pH on the electrochemical behavior of X70 pipeline steel in simulated solution according to the orthogonal testing method. The results showed that temperature, dissolved oxygen concentration and pH had great influence on corrosion current density (icorr)of X70 steel. Corrosion current density of X70 steel was most influenced by dissolved oxygen concentration in simulated solution. The corrosion degree of X70 steel was the least under the environment of low temperature, deficient oxygen and weak acid.

  8. Development of API 5L X70 and X80 in the Brazilian Vallourec and Mannesmann Tubes industry; Desenvolvimento de acos API 5L X70 e X80 na Vallourec e Mannesmann Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Julio M. Silveira e; Carvalho, Ricardo N. de [Vallourec and Mannesmann Tubes - V e M do Brasil, Belo Horizonte, MG (Brazil)

    2000-07-01

    The demand for seamless pipes with resistance higher than those for API 5L X60 and X65 grades has increased in the last years. They are traditionally used up to now for applications on rigid risers for production and exportation and line pipes for oil and gas. In the case of seamless pipes, the great challenge is to fulfill the requirements of mechanical properties for X70 and X80 grades, quenched and tempered, with values of carbon equivalent low enough to assure a good weldability. This paper presents the results obtained by Vallourec and Mannesmann Tubes - V and M do Brazil on producing seamless pipes of X70 and X80 API grades, with outside diameter lower than 8 5/8{sup (} 219,1 mm ) and wall thickness up to 0,562{sup (} 14,3 mm ). Results of tensile, Charpy notch impact resistance and hardness tests are shown. Hydrogen-Induced and Environmental Cracking tests were also carried out, since for some applications is required a good resistance to these kinds of embrittlement mechanisms. The mechanical properties, microstructure and physical characteristics of welded joints were also evaluated. The results obtained up to now are quite promising, showing good suitability to the aimed final applications. (author)

  9. Tension fracture behaviors of welded joints in X70 steel pipeline

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The surface of welded joints in X70 steel pipeline was processed by laser shock wave, its mechanical behaviors of tension fracture were analyzed with tension test,and the fracture morphologies and the distributions of chemical element were observed with scanning electron microscope and energy dispersive spectrum,respectively.The experimental results show that the phenomenon of grain refinement occurs in the surface of welded joints in X70 steel pipeline after the laser shock processing,and compressive re...

  10. Research & Development of Grade X70 LSAW Steel Pipes for West-East Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    WangXiaoxiang; SunQi

    2004-01-01

    In this article the research and development of X70 large diameter longitudinal seam submerged arc welded (LSAW) steel pipes for West-East Gas Transportation Pipeline project (WEGTP) in China are introduced, including the key technique, fabrication of pipe production line, mass production and the latest progress of LSAW steel pipe technique.

  11. Anodic Dissolution of API X70 Pipeline Steel in Arabian Gulf Seawater after Different Exposure Intervals

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2014-01-01

    Full Text Available The anodic dissolution of API X70 pipeline steel in Arabian Gulf seawater (AGSW was investigated using open-circuit potential (OCP, electrochemical impedance spectroscopy (EIS, cyclic potentiodynamic polarization (CPP, and current-time measurements. The electrochemical experiments revealed that the X70 pipeline steel suffers both general and pitting corrosion in the AGSW solution. It was found that the general corrosion decreases as a result of decreasing the corrosion current density (jcorr, corrosion rate (Rcorr and absolute currents as well as the increase of polarization resistance of X70 with increasing the exposure time. On the other hand, the pitting corrosion was found to increase with increasing the immersion time. This was confirmed by the increase of current with time and by the SEM images that were obtained on the steel surface after 20 h immersion before applying an amount of 0–.35 V versus Ag/AgCl for 1 h.

  12. Development of high strength pipes grade API 5L X70 PSL2 offshore by the HFIW Process (High Frequency Induction Welding)

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, Wilson R.; Melo, Luis C.R.; Gomes, Igor O.; Boni, Luiz P.; Sanctis, Marco A.M. di [Apolo Tubulars, Lorena, SP (Brazil)

    2009-07-01

    High strength pipes can be manufactured with excellency in dimensional tolerances, rapidity and efficiency through HFIW process (High Frequency Induction Welding). API 5L 6 5/8 x 0,374 in pipes were made of thin, hot rolled and coiled plates with dimensional 9,300 x 1.040,0 x 140.000 mm. Mechanical tests, chemical and microstructural analysis were performed. For the microstructural analysis, ferrite and perlitic structure were detected. All the results obtained are according to API 5L, 44{sup th} edition, 2008 for the grade API 5L X70 PSL2 Offshore. (author)

  13. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

    Institute of Scientific and Technical Information of China (English)

    Shengrong Wang; Cuiwei Dun; Xiaogang Li; Zhiyong Liunn; Min Zhu; Dawei Zhang

    2015-01-01

    The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM),energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface.α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS) are consistent with potentiodynamic polarization tests.

  14. A new method for preparing bionic multi scale superhydrophobic functional surface on X70 pipeline steel

    Science.gov (United States)

    Yu, Sirong; Wang, Xiaolong; Wang, Wei; Yao, Qiang; Xu, Jun; Xiong, Wei

    2013-04-01

    The hydrophobic property of a rough surface with a low free energy coating was theoretically analyzed in this paper. In order to obtain a superhydrophobic surface, a rough surface morphology must be formed in addition to the low free energy coating on the surface. Through the shot blasting, chemical etching with concentrated hydrochloric acid, and low free energy modification with myristic acid ethanol solution, the superhydrophobic surface was obtained on X70 pipeline steel. The better process parameters for preparing superhydrophobic surface on X70 pipeline steel were obtained. The diameter of the stainless steel shot used in the shot blasting was 0.8-1.0 mm. The concentration of hydrochloric acid was 6 mol/L. The chemical etching time was 320 min. The concentration of myristic acid ethanol solution was 0.1 mol/L. The soaking time in myristic acid ethanol solution was 72 h. After X70 pipeline steel surface was treated using the process parameters mentioned above, the biggest contact angle between the specimen surface and distilled water was 153.5°, and the sliding angle was less than 5°.

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

    International Nuclear Information System (INIS)

    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.

  16. CORROSION INHIBITION OF X70 STEEL IN SALINE SOLUTION SATURATED WITH CO2 BY THIOUREA

    Institute of Scientific and Technical Information of China (English)

    X.Y. He; H.Y. Deng; R. Li; X.D. Fei; H.Y. Wang; Z.Y. Deng

    2008-01-01

    Corrosion monitoring techniques were performed on X70 steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies(IE) of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.

  17. Effects of Cl- and SO2-4 Ions on Corrosion Behavior of X70 Steel

    Institute of Scientific and Technical Information of China (English)

    Junwei WU; Xiaogang LI; Cuiwei DU; Song WANG; Yiquan SONG

    2005-01-01

    Corrosion behaviors of X70 steel were studied by means of electrochemical experiments and morphology observation.First, through potentiodynamic polarization in solution of various Cl- ions concentration, it was found that Epit began to appear in solution of Cl- concentration above 0.1 mol/L, and there was a critical point of Cl- concentration between 0.05 mol/L and 0.1 mol/L, below which the extent of pitting and general corrosion were trivial, while in solution of Cl- concentration above 0.1 mol/L, general and pitting corrosion became greater as the increasing of Cl- concentration. All of them were confirmed by the SEM observations after anodic polarization. Second, via the potentiodynamic polarization curves of X70 steel in 0.5 mol/L Cl- solution with 0, 0.05, 0.5 and 1 mol/L SO42-ions, it was found SO42- ions were able to inhibit corrosion aroused from Cl- ions, accordingly a model was set up to describe the process. In addition, to further explore the inhibited effect of SO42- ions, EIS was used in solutions of different Cl- and SO42- concentrations, the results revealed that the e(ectrochemical resistance has a relation with the [SO42-]/[Cl-], that was, the bigger the value of [SO42-]/[Cl-], the greater the electrochemical resistance.

  18. Study of microstructures and properties for girth welding of domestic X70 pipeline steels

    Institute of Scientific and Technical Information of China (English)

    Li Yuntao; Du Zeyu; Tao Yongyin; Xiong Linyu

    2008-01-01

    With the development of domestic pipeline steels, it is necessary to develop suitable welding technology which can improve the properties of the welded pipeline. In this paper, the microstructures and mechanical properties of domestic X70 pipeline steels and welded joints are discussed. The welding consumables of BOHLER E6010 and HOBART 81N1 are matched for girth welding. The following characteristics in heat-affected zone(HAZ) are indicated that microstructures of intercritical HAZ(ICHAZ) is finer and more uniform, the grain sizes of fine-grain HAZ(FGHAZ) and subcritical HAZ(SCHAZ) are smaller than that of coarse-grain HAZ(CGHAZ). The hardness, tensile strength and toughness of welded joints come up to the standard. The micrographs of impact specimens in welded joints are cleavage, quasi-cleavage and dimple which shows there is typical ductile rupture.

  19. Correlation of microstructure and fracture properties of API X70 pipeline steels

    Science.gov (United States)

    Hwang, Byoungchul; Kim, Young Min; Lee, Sunghak; Kim, Nack J.; Ahn, Seong Soo

    2005-03-01

    Effects of microstructure on fracture toughness and transition temperature of high-toughness X70 pipeline steels were investigated in this study. Three types of steels were fabricated by varying alloying elements such as C, Cu, and Mo, and their microstructures were varied by rolling conditions such as finish rolling temperature and finish cooling temperature. Charpy V-notch (CVN) impact tests and pressed notch drop-weight tear tests (DWTT) were conducted on the rolled steel specimens. The charpy impact test results indicated that the specimens rolled in the single-phase region of the steel containing a reduced amount of C and Mo had the highest upper shelf energy (USE) and the lowest energy transition temperature (ETT) because of the appropriate formation of acicular, quasipolygonal, or polygonal ferrite and the decreased fraction of martensite-austenite constituents. Most of the specimens rolled in the single-phase region also showed excellent DWTT properties as the percent shear area (pct SA) well exceeded 85 pct, irrespective of finish cooling temperatures, while their USE was higher than that of the specimens rolled in the two-phase region. Thus, overall fracture properties of the specimens rolled in the single-phase region were better than those of the specimens rolled in the two-phase region, considering both USE and pct SA.

  20. Relationship between electrochemical characteristics and SCC of X70 pipeline steel in an acidic soil simulated solution

    Institute of Scientific and Technical Information of China (English)

    Zhiyong LIU; Xiaogang LI; Yingrui ZHANG; Cuiwei DU; Guoli ZHAI

    2009-01-01

    Stress corrosion cracking (SCC) of X70 pipeline steel in simulated solution of the acidic soil in Yingtan in China was investigated using slow strain rate test (SSRT), SEM and potentiodynamic polarization technique. Experiment results indicate that X70 steel is highly susceptible to SCC as applied potential reduces, which is manifested in loss of toughness and brittle fracture. Constant polarization current can detect the occurrence of SCC. The lower the polarization current is the sooner stress corrosion cracking occurs. The SCC mechanisms are different at varying potentials. When potential is higher than open circuit potential, anodic process controls SCC, whereas when potential is far lower than open circuit potential, cathodic process controls SCC, and between these two potential regions, a combined electrochemical process controls the SCC. Stress or strain has a synergistic effect with electrochemical reactions to accelerate the cathodic hydrogen evolution process, which makes the X70 pipeline steel to be more susceptible to SCC.

  1. Electrochemical Behavior and Stress Corrosion Sensitivity of X70 Steel Under Disbonded Coatings in Korla Soil Solution

    Science.gov (United States)

    Qian, Hongchang; Wang, Luntao; Wang, Huiru; Zheng, Wenru; Zhang, Dawei; Du, Cuiwei

    2016-09-01

    The corrosion of X70 pipeline steel under a model disbonded coating was studied in a simulated solution of Korla soil by combining in situ electrochemical measurements at different locations in the crevice and stress corrosion cracking (SCC) sensitivity analyses in the corresponding simulated environments. The results from electrochemical impedance spectroscopy showed that the corrosion product resistance R t and charge transfer resistance R ct of X70 steel first increased and then decreased with increasing distance from the opening of the crevice in the disbonded coating. Scanning electron micrographs showed that pitting in the crevice became more severe at deeper locations in the crevice. Slow strain rate tests showed that the lowest SCC sensitivity of X70 steel was found at 15 cm away from the opening, and the highest SCC sensitivity was at the end of the crevice.

  2. Oblique Y-groove cracking test of the welding cold cracking susceptibility of domestic X-70 pipeline steel

    Institute of Scientific and Technical Information of China (English)

    陈丽萍; 杜则裕; 李云涛; 李九生

    2002-01-01

    "Gas Transmitting From West to East Project" is significant. It should ensure the welding quality and safety of pipeline. The task is very arduous to guarantee the quality of the project in the condition of long line, complex weather and geology features. In this paper, the welding cold cracking susceptibility of domestic X-70 pipeline steel adopted by the project, which is one of the most interesting questions of welding quality about petrol pipeline, was studied by means of oblique Y-groove cracking test. The crack ratio of surface and section was tested under the conditions of different welding materials and preheat temperature .The X-70 pipeline steel has good crack resistance. The research has important value for the construction of large-scale pipeline engineering and the application of domestic X-70 pipeline steel.

  3. X70管线钢焊接接头断裂韧性分析%Fracture Toughness of X70 Pipeline Steel Welded Joints

    Institute of Scientific and Technical Information of China (English)

    祝少华; 杨军; 张万鹏; 张超

    2013-01-01

    The crack tip opening displacement (CTOD) test is usually used to evaluate material toughness. In this article, it detailedly introduced CTOD test procedure, operation steps and fitting method of calculation. In addition, it adopted CTOD test to conduct fracture toughness study for the weld in welded joints, HAZ and base metal of X70 Pipeline steel. The result showed that under the same temperature, the CTOD characteristic valuesδ0.05,δ0.2 andδ0.2BL of base metal is the highest, the HAZ is the second, and the weld is the lowest, that is to say the fracture toughness of base metal is the best, the fracture toughness of HAZ is better than that of weld, and the weld is the worst.%裂纹尖端张开位移(CTOD)试验常被用来进行材料的韧性评价。详细介绍了CTOD试验的过程、操作步骤及计算拟合方法。并采用裂纹尖端张开位移试验对X70管线钢焊接接头处焊缝、热影响区(HAZ)和母材进行了断裂韧性的测试研究。结果表明,在同一温度下, CTOD特征值δ0.05,δ0.2和δ0.2BL均呈现母材最大、热影响区次之、焊缝最小,即母材断裂韧性最优、热影响区次之、焊缝最差。

  4. X70管线钢焊缝弯曲不合格原因分析%Analysis on Weld Bending Disqualified Reason of X70 Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    陈晓林

    2011-01-01

    检验管线钢管焊接接头塑性性能最直接、最有效的方法是弯曲试验.简要介绍了X70管线钢管的力学性能、主要化学成分、弯曲试验条件以及API SPEC 5L中对弯曲试验合格试样的判定标准.从焊缝的夹渣及气孔、脆性断裂、焊趾开裂和裂纹源等方面分析了弯曲试验不合格的现象及产生原因.最后分别给出了降低夹渣及气孔、脆性断裂、焊趾开裂等缺陷的具体措施.%The most direct and the most effective method to check welded joint plasticity of line pipe is bending test In this article,it briefly introduced the mechanical performance,main chemical compositions,bending test condition and judgment standard to qualified specimen in API SPEC 5L,and analyzed disqualified phenomena and cause for bending test from weld inclusions,gas pocket,brittle fracture,welding toe cracking,crack source and etc. Finally,it gave specific measures to reduce inclusions,gas pocket,brittle fracture,welding toe cracking and etc.

  5. Texture Study Across Thickness of API X70 Steel After Hot Deformation and Different Posttreatments

    Science.gov (United States)

    Masoumi, M.; Herculano, L. F. G.; Almeida, A. A.; Béreš, M.; de Abreu, H. F. G.

    2016-01-01

    In the present study, the texture heterogeneity across the thickness of API X70 steel subjected to hot deformation and different posttreatments was investigated. X-ray diffraction and electron backscattered diffraction were used to analyze crystallographic orientation and grain boundary distributions at the center and surface layers of specimens. The initial material was rolled at 1000°C to 67% reduction; then one deformed sample was cooled in air, and the others were quenched in water and finally tempered at 350°C and 700°C for 1 h. The shear strain generated by friction between rolls and strip induces heterogeneity across thickness. The results showed that in the center layer, the (001)[ bar{1}bar{1}0 ] texture dominated in all specimens, whereas the {110}//ND component was developed at the surface layer. Furthermore, a local misorientation histogram showed that the surface layer was subjected to a higher degree of deformation in comparison with the center layer due to additional shear deformation.

  6. Research on anti-corrosion property of rare earth inhibitor for X70 steel

    Institute of Scientific and Technical Information of China (English)

    ZHU Yanhua; ZHUANG Jia; YU Yongsheng; ZENG Xianguang

    2013-01-01

    Three kinds of rare earth nitrates were adopted to sodium molybdate to get three kinds of LnN-M compounded inhibitors (La(NO3)3+Na2MoO4(LaN-M),Ce(NO3)3+Na2MoO4(CeN-M),Pr(NO3)3+Na2MoO4(PrN-M)).The combination of weight-loss method and the electrochemical test,was used to evaluate and analyze the corrosion inhibition efficiency of these LnN-M inhibitors to make the research on their corrosion inhibition performance,and the sequential order of their performance was found as follows:CeN-M> LaN-M>PrN-M,among which,the inhibition efficiency of CeN-M for the X70 steel could reach 98.21%.The synergism parameters were calculated by weight-loss method,these computational data indicated that the synergistic effect between rare earth nitrates and sodium molybdate was obvious and significant.Surface morphology,chemical composition and phase components of the precipitation films were tested for discussing the mechanism of LnN-M inhibitors.The outer electronic configuration of the lanthanide was found to have an important influence on the inhibition efficiency.The CeN-M inhibitor was discovered to have the best inhibition effect with the amorphous cerium oxides.The results of this research revealed that the precipitation films formed on the surface of the steel samples had a crucial influence on the inhibition efficiencies after adding LnN-M inhibitors.

  7. 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

  8. Influence of crystallographic texture in X70 pipeline steels on toughness anisotropy and delamination

    Science.gov (United States)

    Al-Jabr, Haytham M.

    The effects of microstructure and crystallographic texture in four commercially-produced API X70 pipeline steels and their relation to planar anisotropy of toughness and delamination were evaluated. The experimental steels were processed through either a hot strip mill, a Steckel mill, or a compact strip mill. Different processing routes were selected to obtain plates with potential variations in the microstructure and anisotropic characteristics. Tensile and Charpy impact testing were used to evaluate the mechanical properties in three orientations: longitudinal (L), transverse (T) and diagonal (D) with respect to the rolling direction to evaluate mechanical property anisotropy. The yield and tensile strengths were higher in the T orientation and toughness was lower in the D orientation for all plates. Delamination was observed in some of the ductile fracture surfaces of the impact samples. To further study the splitting behavior and effects on impact toughness, a modified impact test (MCVN) specimen with side grooves was designed to intensify induced stresses parallel to the notch root and thus facilitate evaluation of delamination. Scanning electron microscopy combined with electron backscattered diffraction (EBSD) were used to evaluate the grain size, microstructural constituents, and crystallographic texture to determine the factors leading to delamination and the anisotropy in toughness. The ferrite grain size is mainly responsible for the differences in DBTTs between the L and T orientations. The higher DBTT in the D orientation observed in pipeline steels is attributed to crystallographic texture. The higher DBTT in the D direction is due to the higher volume fraction of grains having their {100} planes parallel or close to the primary fracture plane for the D orientation. An equation based on a new "brittleness parameter," based on an assessment of grain orientations based on EBSD data, was developed to predict the changes in DBTTs with respect to sample

  9. DECREASING PITTING SUSCEPTIBILITY OF PASSIVE FILMS ON X70 PIPELINE STEEL IN NaCl SOLUTIONS BY ILLUMINATION

    Institute of Scientific and Technical Information of China (English)

    W.C. Zhu; W.H. Leng; J.Q. Zhang; C.N. Cao

    2006-01-01

    The influence of UV illumination on passivity and pitting susceptibility on X70 pipeline steel in a borate buffer (pH=8.4) solution containing NaCl is described. It is observed that illumination of the sample leads to a decrease in its pitting susceptibility as indicated by pitting potential and incubation time measurements in chloride containing electrolytes. This effect is strongly dependent on the applied potential during passivation. The electronic properties of the passive films on X70steel were studied by Mott-Schottky analysis and photocurrent transient measurements. The results indicated that illumination during passivation led to modifications in the electronic properties of the passive films, mainly to a decrease of the bulk doping and an increase in the surface state density. The cause for the decrease in the pitting susceptibility is preliminary explained in terms of such modifications of the passive film.

  10. Correlation of microstructure and charpy impact properties in API X70 and X80 line-pipe steels

    International Nuclear Information System (INIS)

    This study aims at correlating microstructure and Charpy impact properties in high-toughness API X70 and X80 line-pipe steels. Three kinds of steels were fabricated by varying alloying elements and hot rolling conditions, and their microstructures and Charpy impact properties were investigated. In addition, their effective grain sizes were characterized by the electron back-scatter diffraction (EBSD) analysis. The Charpy impact test results indicated that the steels rolled in the single phase region had the higher upper shelf energy (USE) than the steel rolled in the two phase region because their microstructures were composed of acicular ferrites. In the X80 steel rolled in the single phase region, the decreased energy transition temperature (ETT) could be explained by the decrease in the overall effective grain size due to the presence of acicular ferrite having smaller effective grain size. Thus, it had excellent mechanical properties in yield and tensile strengths, absorbed energy, and transition temperature, except in ductility

  11. Electrochemical corrosion behaviour of grade X70 and X80 pipeline steels%X70和X80管线钢的电化学腐蚀行为

    Institute of Scientific and Technical Information of China (English)

    李红英; 康巍; 胡继东; 刘洋

    2011-01-01

    通过极化曲线和交流阻抗谱测试以及OM表面腐蚀形貌观察、SEM和TEM的组织观察,研究了Cl-和SO42-离子对X70和X80两种管线钢腐蚀过程的作用机理与规律。结果表明:Cl-有强穿透性,极易引起点蚀,两种钢的自腐蚀电流密度都随着Cl-浓度的增大而增大,点蚀和全面腐蚀也随之进一步加剧,X70钢在较低浓度的NaCl溶液中出现全面腐蚀和点蚀,X80钢仅在高浓度NaCl溶液中出现明显的点蚀,且在各种不同浓度溶液中腐蚀程度均没有X70钢严重。SO42-在金属表面吸附能力比Cl-强,少量SO42-在金属表面的吸附,造成Cl-的局部含量高,更易引起点蚀,而大量SO42-在金属基体表面覆盖,能阻碍Cl-的影响。X80钢比X70钢有更强的耐腐蚀性,X70钢对SO42-和Cl-的作用更为敏感。%Corrosion mechanism and corrosion process of Cl-and SO42-ions on grade X70 and X80 pipeline steels were studied by means of polarization curves,electrochemical impedance spectroscopy,OM,SEM and TEM.The results show that Cl-has a strong penetrability,leading to pitting corrosion.The corrosion current density of the steels increases and pitting and general corrosion is aggravated with the increase of Cl-concentration in the solution.Pitting and general corrosion of X70 steel occurs in the NaCl solution of low concentration and only obvious pitting corrosion of X80 steel in the NaCl solution of high-concentration is observed and corrosion degree of X80 steel is less than that of X70 steel in same concentration solution.The adsorption ability of SO42-on the surface of metal is stronger than Cl-,a small amount of SO42-that adsorbs on the surface of metal to cause higher local content of Cl-causes more pitting,however a large amount of SO42-can cover on the surface of metal to hinder the influence of Cl-.X70 steel is more sensitive to the effect of SO42-and Cl-compared with X80 steel,and X80 steel exhibits higher corrosion resistance than X70 steel.

  12. Effect of alloy elements on toughness of X70 pipeline steels%微合金元素对X70管线钢韧性的影响

    Institute of Scientific and Technical Information of China (English)

    李红英; 胡继东; 李阳华

    2012-01-01

    Toughness of four X70 pipeline steels with different composition was studied by using charpy impact test and dropweight tear test( DWTT). The effects of microstructure, grain size, grain orientation and misorientation angle distribution, and inclusions on toughness of the steels were analysed by means of optical microscope ( OM ) , scanning electrical microcopy ( SEM ) and the electron backscatter diffraction technique(EBSD). The results show that the eharpy impact toughness and DWTT values of the pipeline steels containing Mo and Ni are higher, the DWTT values of pipeline steels containing Cr are unqualified. The toughness of X70 pipeline steels increases with higher ratio of large angle grain boundaries, less inclusions and finer effective grain size.%研究了4种含不同微合金元素的X70管线钢的韧性,采用夏比冲击试验和落锤撕裂试验,借助金相显微镜(OM)、扫描电镜(SEM)与背散射电子衍射技术(EBSD)等手段,分析了微观组织、晶粒尺寸、晶粒取向及取向差和夹杂物等因素对X70管线钢韧性的影响。结果表明,含Mo、Ni元素的管线钢夏比冲击韧性和落锤性能都较好,含Cr元素的管线钢落锤性能偏低,大角度晶界比率越高,晶粒尺寸越细小,夹杂物含量越少的管线钢具有更高的韧性。

  13. Effect of pH Value on Stress Corrosion Cracking of X70 Pipeline Steel in Acidic Soil Environment

    Institute of Scientific and Technical Information of China (English)

    Zhiyong LIU; Cuiwei DU; Xin ZHANG; Fuming WANG; Xiaogang LI

    2013-01-01

    The effect of pH value on the stress corrosion cracking (SCC) of API X70 pipeline steel in simulated acidic soil solutions was investigated by using slow strain rate test,electrochemical polarization curves,electrochemical impedance spectroscopy,and scanning electron microscopy.pH plays an important role in the susceptibility and electrochemical mechanism of SCC.The pH higher than 5 has no significant effect on electrochemical processes.By contrast,the pH lower than 5 intensifies cathodic hydrogen evolution reactions,thus increasing the cathodic current and corrosion potential.Under different pH values,the SCC mechanism of X70 pipeline steel varies among anodic dissolution (AD),hydrogen embrittlement (HE),and the combination of AD and HE (AD + HE) with variations of applied potential.At-850 mVSCE,the SCC mechanism is HE if pH is less than 4 or AD + HE if pH value is more positive.

  14. Effect of Cyclic Loading on Cracking Behaviour of X-70 Pipeline Steel in Near-Neutral pH Solutions

    Institute of Scientific and Technical Information of China (English)

    Hao GUO; Guangfu LI; Xun CAI; Ruipeng YANG; Wu YANG

    2005-01-01

    The cracking behaviour of X-70 pipeline steel in near-neutral pH solutions was studied under different modes of cyclic loading. The crack propagation process of X-70 pipeline steel under low frequency cyclic loading condition was controlled mainly by stress corrosion cracking (SCC) mechanism. Under mixed-mode cyclic loading, both higher tensile stress and shear stress made cracks easier to propagate. Applied cathodic potentials and high content of carbon dioxide in solutions also promoted the propagation of cracks. The propagation directions of cracks were different under different cyclic loading conditions. Under mode I (pure tensile stress) cyclic loading condition, cracks were straight and perpendicular to the tensile stress axis, while under mixed-mode Ⅰ/Ⅲ (tensile/shear stress) cyclic loading,cracks were sinuous and did not propagate in the direction perpendicular to the main tensile stress axis. Under the mixed-mode cyclic loading, cracks were much easier to propagate, suggesting that shear stress intensified the role of tensile stress. In addition, shear stress promoted the interaction between cracks, resulting in easier coalescence of cracks.

  15. Static Recrystallized Grain Size of Coarse-Grained Austenite in an API-X70 Pipeline Steel

    Science.gov (United States)

    Sha, Qingyun; Li, Guiyan; Li, Dahang

    2013-12-01

    The effects of initial grain size and strain on the static recrystallized grain size of coarse-grained austenite in an API-X70 steel microalloyed with Nb, V, and Ti were investigated using a Gleeble-3800 thermomechanical simulator. The results indicate that the static recrystallized grain size of coarse-grained austenite decreases with decreasing initial grain size and increasing applied strain. The addition of microalloying elements can lead to a smaller initial grain size for hot deformation due to the grain growth inhibition during reheating, resulting in decreasing of static recrystallized grain size. Based on the experimental data, an equation for the static recrystallized grain size was derived using the least square method. The grain sizes calculated using this equation fit well with the measured ones compared with the equations for fine-grained austenite and for coarse-grained austenite of Nb-V microalloyed steel.

  16. 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)

  17. Study on the microstructure and hardness of in-service welded joint of X70 pipeline steel

    Institute of Scientific and Technical Information of China (English)

    Chen Yuhua; Wang Yong; Liu Geping

    2007-01-01

    Hydrogen induced cracking (HIC) is one of the main problems of in-service welding onto active pipeline. Microstructure and hardness of welded joint have a vital effect on hydrogen induced cracking. The microstructure and hardness of welded joint of X70 pipeline steel were studied using simulation in-service welding device. The results show that the main microstructures of in-service welded seam are grain boundary ferrite, intracrystalline acicular ferrite, as well as small amount of widmanstatten structure. The main microstructures of coarse grain heat-affected zone (CGHAZ) are coarse granular bainite, lath ferrite and martensite. Metastable phases such as martensite and lath ferrite are found in CGHAZ because of the too quick cooling velocity and the hardness of the CGHAZ is high.

  18. Corrosion of A3,20# and X70 Steels in Simulated Flowing Seawater%A3、20#和X70钢室内模拟流动海水腐蚀试验

    Institute of Scientific and Technical Information of China (English)

    程浩力; 刘德俊

    2012-01-01

    设计并建立了实验室模拟流动海水腐蚀试验装置。对A3、20#、X70钢挂片和20#钢管路在流动人工海水中全浸暴露2、4、8、16、32天的腐蚀行为进行了试验研究。试验结果表明,流动海水中碳钢的腐蚀速率先降后升,然后趋于稳定;在动水试验中,锈层分为两层,底层以Fe3O4为主,表层以Fe2O3为主;在静水试验中,锈层以Fe2O3为主。%A simulated flowing seawater corrosion test system was set up,the corrosion behaviors of carbon steels in simulated seawater were studied using the system.The weight loss tests of A3,20# and X70 steels were conducted to show the corrosion rate data in static and flowing seawater for comparison.Results showed that the corrosion of A3,20# and X70 steels was accelerated in the flowing seawater due to the erosion-corrosion effect on the surfaces of metal materials.The corrosion rate showed a decrease first and then an increase,and gradually became stable later.The rust layers were divided significantly into two layers in the flowing water experiment.

  19. Effect of deformation and cooling rate on the transformation behavior and microstructure of X70 steels

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of the deformation in the non-recrystallization region of austenite and the cooling rate on the transformation behavior and microstructure of low-carbon low-alloy steel for pipeline application were studied on the thermal-mechanical simulator Gleeble-1500. It was shown that an increase in deformation amount can greatly increase the nucleation site of ferrite when deformed in the non-recrystallization region of austenite, and an increase in nucleation ratio can greatly refine grains. When the cooling rate is accelerated, the driving force of nucleation is increased and the nucleation rate also improves. Ultra-refine grains can be obtained by controlled rolling. The high density of ferrite nucleus, which forms along the austenite grain boundary, twin interface, and deformation band are introduced in the matrix of austenite by the control of hot rolling, after which the microstructure can be refined. It was found that the acicular ferrite has a very fine sub-structure, high dislocation density, and a thin slab with ultra-fine grains. Small M/A islands and cementite are precipitated on the matrix of the slabs by the analysis technique of TEM and SEM.

  20. Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhixiong, E-mail: zhixiongzhu@gmail.com [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Kuzmikova, Lenka; Li, Huijun [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Barbaro, Frank [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); CBMM Technology Suisse, 14, Rue du Rhone, Geneva 1204 (Switzerland)

    2014-05-01

    This study investigated the influence of the inter-critical reheating temperature on the microstructure and mechanical properties of a coarse grained heat affected zone (CGHAZ) in an API 5L grade X70 pipeline steel seam weld. A Gleeble 3500 thermo-mechanical simulator was employed to duplicate particular weld thermal cycles in order to accurately assess specific regions of the weld HAZ. Detailed microstructural analysis, including investigation of the martensite–austenite (M–A) constituent, was performed using optical microscope (OM), scanning electron microscope (SEM) and selective etching techniques. It is shown that the fracture toughness of the CGHAZ is significantly reduced following exposure to a subsequent inter-critical thermal cycle. Fracture toughness gradually improves as the inter-critical temperature is increased, but does not return to the value of the original CGHAZ due to the presence of isolated large M–A particles and coarse microstructure. Significance of M–A particles to the HAZ fracture toughness is first related to the location of particles along prior austenite grain boundaries, followed by the size of individual M–A particles.

  1. Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel

    International Nuclear Information System (INIS)

    This study investigated the influence of the inter-critical reheating temperature on the microstructure and mechanical properties of a coarse grained heat affected zone (CGHAZ) in an API 5L grade X70 pipeline steel seam weld. A Gleeble 3500 thermo-mechanical simulator was employed to duplicate particular weld thermal cycles in order to accurately assess specific regions of the weld HAZ. Detailed microstructural analysis, including investigation of the martensite–austenite (M–A) constituent, was performed using optical microscope (OM), scanning electron microscope (SEM) and selective etching techniques. It is shown that the fracture toughness of the CGHAZ is significantly reduced following exposure to a subsequent inter-critical thermal cycle. Fracture toughness gradually improves as the inter-critical temperature is increased, but does not return to the value of the original CGHAZ due to the presence of isolated large M–A particles and coarse microstructure. Significance of M–A particles to the HAZ fracture toughness is first related to the location of particles along prior austenite grain boundaries, followed by the size of individual M–A particles

  2. PITTING CORROSION OF X70 PIPELINE STEEL IN THE SIMULATED WET STORAGE ENVIRONMENT%X70钢在模拟潮湿存储环境中的点蚀行为

    Institute of Scientific and Technical Information of China (English)

    刘智勇; 董超芳; 贾志军; 李晓刚

    2011-01-01

    Pitting mechanism and behaviour of X70 pipeline steel in humid storage environ ments were investigated using electrochemical polarization curves, electrochemical impedance spec trums (EIS), immersing corrosion tests and corrosion morphology observation through SEM. It was demonstrated that pitting of X70 pipeline steel occurred in simulated moist storage environments, for which the corrosive substances came from the residual species in laminar cooling water introduced during steel manufacture processes. HCO3- and NOJ are passivating agents, Cl- and SO42- would destroyed the passivation layer, which could lead to pitting. In solution with 0.5 mol/L NaHCO3, 0.02 mol/L Cl- was enough to break the passivation layer. Cl- concentration is a key factor for pit ting initiation and propagation. When the Cl- concentration was relatively low, pitting could initiate but was hard to grow up. When the Cl- concentration was moderate (about 0.149 mol/L), pitting sensitivity was the highest because pitting was easy to grow up. However, if the concentration of Cl-was too high, uniform corrosion occurred.%应用电化学极化技术、电化学阻抗谱、模拟浸泡实验,研究了X70钢在模拟潮湿存储环境中点蚀的发生机制及规律.结果表明,X70钢在模拟潮湿存储环境中可以发生点蚀,导致点蚀发生的腐蚀介质来自于层流冷却水中的腐蚀性物质,其中HCO-3和NO-3是致钝剂,而Cl-和SO42-可破坏钝化膜,促进点蚀发生.在0.5 mol/L的NaHCO3介质中当Cl-浓度达到0.02 mol/L时钝化膜即失去保护性.CI-浓度是影响点蚀的萌生和发展的关键因素,当其浓度较低时点蚀容易形核,但仅有少数能够长大;而当其浓度适中(约0.149 mol/L)时点蚀敏感性最高,点蚀容易长大;当其浓度过高时发生均匀腐蚀,点蚀难以长大.

  3. The effect of processing parameters on the dynamic recrystallisation behaviour of API-X70 pipeline steel

    International Nuclear Information System (INIS)

    The effect of deformation temperature and strain rate on the dynamic recrystallisation (DRX) behaviour of X70 pipeline steel was investigated. DRX parameters such as the critical and peak stresses and strains as well as the deformation activation energy were determined in the temperature range between 925 °C and 1125 °C for strain rates of 0.1, 1 and 5 s−1. The relationship between the peak stresses and strains with the Zener–Hollomon parameter was determined. The dynamically recrystallised volume fraction was computed as a function of the different temperatures and strain rates. The APRGE software was applied for the first time on electron back-scattering diffraction data of dynamically recrystallised microstructures in order to reconstruct the prior austenite from the as-quenched martensite phase. The dynamically recrystallised flow stress curves and microstructure were also predicted using cellular automata modelling. The results show an earlier onset of DRX with a decrease in strain rate or an increase in deformation temperature. The dynamically recrystallised grain size is also found to decrease with an increase in strain rate and a lowering of deformation temperature

  4. RECRYSTALLIZATION BEHAVIOR AND PRIOR AUSTENITE GRAIN BOUNDARY CORROSION IN THE PLANE STRAIN COMPRESSION CONDITION FOR A LOW CARBON X70 PIPELINE STEEL

    Institute of Scientific and Technical Information of China (English)

    Y.H. Li; J. Wang; Y.S. Li; Y. Y. Shan

    2004-01-01

    Recrystallization behavior of a low carbon X70 pipeline steel was studied in the plane strain compression condition. It was found that the dynamic recovery but no dynamic recrystallization occurred in the current experimental condition. A method for examining the prior austenite grain boundary corrosion was supposed.

  5. 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)

  6. Ferrite transformation kinetics of X70 pipeline steel during continuous cooling%连续冷却过程中 X70管线钢的铁素体相变动力学

    Institute of Scientific and Technical Information of China (English)

    谢保盛; 蔡庆伍; 余伟; 曹嘉明; 杨云峰

    2014-01-01

    Thermal expansion curves of X 70 pipeline steel during continuous cooling process were tested on DIL 805 dilatometer .Based on experimental results , the start temperature of austenite to ferrite transformation among two models were analyzed , and the key parameters of ferrite transformation were obtained by reverse regression method with the JMAK equation , thus the kinetics during continuous cooling process were determined.The results show that, the optimal n and k can be obtained by the method mentioned above .In models, n is set as 0.5, 1, 1.5, 1-0.5X2 respectively to calculate the transformation kinetics , where X represents transformation volume fraction .In terms of n value characterized by 1-0.5X2 , it is higher precision and in better agreement with the experimental data than n value set as 0.5, 1, 1.5.In modelⅠ, the predicted results are deviated under high cooling rate , which results from the limitation of ferrite nucleation energy ΔGV . However , while modelⅡjust including two parameters is more availability .To X70 pipeline steel , the relationship between start temperature of ferrite transformation and cooling rate is indicated as Ts=Ae3 -39.1440φ0.4020 .%在DIL805膨胀仪上测量了X70管线钢在连续冷却过程中的热膨胀曲线。根据试验结果,分析比较了两种奥氏体-铁素体相变开始温度模型,并通过对JMAK方程采用逆向回归法确定了铁素体相变分数的关键性参数,从而确定了连续冷却过程中的相变动力学。结果表明,不同冷却速率下的最佳n值和k值可通过JKMA公式逆向回归得出,模型分别采用时间指数n为0.5、1、1.5、1-0.5X2的4种取值方法计算铁素体相变动力学曲线,通过与试验数据的对比发现,用相变体积分数X的函数表征n值的方法计算精度更高,与试验结果吻合更好。模型Ⅰ由于对铁素体体积形核功ΔGV的取值有局限性,使得模型在大冷却速率下的预测结果

  7. X70直缝双面埋弧焊钢管接头缺陷分析%Defects Analysis on Joints of X70 Longitudinally Double Submerged Arc Welded Steel Pipes

    Institute of Scientific and Technical Information of China (English)

    傅如闻; 李蔚; 李绪丰

    2011-01-01

    采用宏观分析、金相检验以及能谱分析等技术,分析了超声波探伤发现的X70直缝双面埋弧焊钢管接头中超标缺陷的性质及形成原因.结果表明:缺陷位于熔合线处,其颜色及形态在抛光态和侵蚀后发生明显变化,缺陷端部未见开叉,两边界面也未见沿晶或穿晶裂纹;缺陷区域的碳和氧元素含量异常升高;从而确认该缺陷既不是钢板中的夹杂物或焊缝中的固体夹杂,也不是裂纹,而是接头中的未熔合缺陷,因坡口表面污物未清除干净引起.%By means of macroscopic analysis, metallographic examination and energy spectrum analysis,properties and formation reasons of the overweight defects which were found by ultrasonic detection in the joints of X70 longitudinal double submerged arc welded steel pipes were analyzed. The results indicate that the defects located at the fusion line and their color and formation had a marked change compared polishing state with erosion state. There was no fish tail at the end of the defects and no inter-granular and trans-crystalline cracks at both sides of the interfacial defects as well. Carbon and oxygen content of the defect region was much higher than that of the normal area. So it can be confirmed that the defects were incomplete fusion which was caused by dirt on groove, not inclusions in the steel plate, and also not solid inclusions or cracks in the welding.

  8. Fracture-Toughness Analysis in Transition-Temperature Region of Three American Petroleum Institute X70 and X80 Pipeline Steels

    Science.gov (United States)

    Shin, Sang Yong; Woo, Kuk Je; Hwang, Byoungchul; Kim, Sangho; Lee, Sunghak

    2009-04-01

    The fracture toughness in the transition-temperature region of three American Petroleum Institute (API) X70 and X80 pipeline steels was analyzed in accordance with the American Society for Testing and Materials (ASTM) E1921-05 standard test method. The elastic-plastic cleavage fracture toughness ( K Jc ) was determined by three-point bend tests, using precracked Charpy V-notch (PCVN) specimens; the measured K Jc values were then interpreted by the three-parameter Weibull distribution. The fracture-toughness test results indicated that the master curve and the 98 pct confidence curves explained the variation in the measured fracture toughness well. The reference temperatures obtained from the fracture-toughness test and index temperatures obtained from the Charpy impact test were lowest in the X70 steel rolled in the two-phase region, because this steel had smaller effective grains and the lowest volume fraction of hard phases. In this steel, few hard phases led to a higher resistance to cleavage crack initiation, and the smaller effective grain size led to a higher possibility of crack arrest, thereby resulting in the best overall fracture properties. Measured reference temperatures were then comparatively analyzed with the index temperatures obtained from the Charpy impact test, and the effects of microstructures on these temperatures were discussed.

  9. STUDY OF THE X70 PIPELINE STEEL CORRODING IN 3.0wt% NaCl SOLUTION USING ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    L.J. Zhang; Z. Zhang; F.H. Cao; J.Q. Zhang; J.M. Wang; C.N. Cao

    2004-01-01

    The corrosion process of the X70 pipeline steel in 3.0wt% NaCl solution were studied using polarization method, and the chronological characteristics during the entire polarization plot were investigated in detail using EIS technique. In the active region of X70 steel such as 20mV potential bias applied on open circuit potential (OCP), the impedance spectra was comprised of three parts: a high-frequency capacitive loop, a middle-frequency capacitive loop and a low-frequency inductive component. When positive polarization potential increased, the capacitive loops at high and middle frequency range merged, and the inductive component at low frequency shrunk. At high positive polarization potential bias (500-800mV vs. OCP), the high-frequency capacitive loop and the low-frequency inductive loop exhibited as disheveled points due to the synergism of the inhomogeneity of the corroding material and the localized corrosion. The results were fitted utilizing the equivalent circuits to simulate the impedance spectra and to interpret the electrochemical features shown during the experiments.

  10. X70管线钢于内蒙古苏里格大气田土壤中的腐蚀特征%Corrosion characteristic of X70 pipeline steel in soil of Sulige Gas Field of Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    霍林桃; 宋义全; 冯光; 冯佃臣; 李涛; 李晓刚

    2007-01-01

    利用SEM,EDS,XRD及失重法研究了X70管线钢在不同含水量的苏里格大气田土壤中的腐蚀行为.实验结果表明,随着含水量的增加,钢的腐蚀速率先增大后减小,水的质量分数为10%时腐蚀速率最大;通过对腐蚀形貌的观察发现,X70钢为不均匀腐蚀;EDS和XRD分析显示X70钢的腐蚀产物主要为铁氧化物(Fe2O3,Fe3O4).

  11. SOIL CORROSION BEHAVIOR OF X70 PIPELINE STEEL IN FIVE AREAS IN INNER MONGOLIA%X70管线钢在内蒙古五地区土壤腐蚀的研究

    Institute of Scientific and Technical Information of China (English)

    冯佃臣; 宋义全; 李涛; 霍林桃; 李晓刚

    2008-01-01

    通过X70管线钢在内蒙古五地区(5个试验站)土壤埋片试验,采用现场埋片的方法,对X70管线钢在土壤中腐蚀进行研究.测定了X70管线钢在各试验站的一年腐蚀率.观察了腐蚀产物的宏观和微观的形貌,并通过EDS和XRD对腐蚀产物进行分析.结果表明:在各地区的腐蚀率相差很大,其中巴盟地区腐蚀率最大为8.2924 g/dm2·d.腐蚀产物主要是Fe3O4.

  12. Effects of Dynamic Strain Hardening Exponent on Abnormal Cleavage Fracture Occurring During Drop Weight Tear Test of API X70 and X80 Linepipe Steels

    Science.gov (United States)

    Kang, Minju; Kim, Hyunmin; Lee, Sunghak; Shin, Sang Yong

    2014-02-01

    In this study, drop weight tear tests (DWTT) were conducted on API X70 and X80 linepipe steels fabricated with various compositions and rolling and cooling conditions in order to correlate the strain hardening with the abnormal cleavage fracture occurring in the hammer-impacted area. Area fractions of fracture modes were measured from fractured DWTT specimens, and the measured data were analyzed in relation to microstructures, Charpy impact energy, and strain hardening. All the steels consisted of fine acicular ferrite, together with some bainitic ferrite, granular bainite, and martensite-austenite constituent. As the volume fraction of acicular ferrite increased, the area fraction of DWTT abnormal cleavage fracture decreased because the toughness of acicular ferrite was higher than other microstructures. The area fraction of abnormal cleavage fracture was weakly related with strain hardening exponents obtained from the quasi-static tensile and compressive tests, but showed better correlation with those obtained from the dynamic compressive test. This tendency could be more clearly observed when steels having similar Charpy impact energy levels were grouped. Since the DWTT was performed under a dynamic loading condition, thus, the abnormal cleavage fracture behavior should be related with the strain hardening analyzed under a dynamic loading condition.

  13. 温度对X70钢在高pH值溶液中腐蚀行为的影响%Effect of Temperature on Electrochemical Corrosion Behavior of X70 Pipeline Steel in High pH Solution

    Institute of Scientific and Technical Information of China (English)

    王冠夫; 陈旭; 赵阳; 韩健; 王彦亮

    2015-01-01

    采用动电位极化、电化学阻抗谱技术、Mott-Schottky等测试方法,研究了温度对X70钢在高pH值溶液(0.5 mol/L Na2CO3+0.5 mol/L NaHCO3)中钝化膜性能和电化学腐蚀行为的影响.结果表明:随着温度升高,X70管线钢的点蚀电位降低,维钝电流密度和钝化膜的极化电阻减小.在实验温度范围内,钝化膜为Fe2O3和Fe3O4的混合物,半导体类型为n型半导体,且不随温度升高而改变.但是随着温度的升高,钝化膜缺陷密度增加,膜厚度减小,腐蚀倾向增大.因此,温度升高会降低钝化膜的稳定性,导致其保护作用下降.

  14. X70管线钢在内蒙古土壤中的腐蚀研究%Corrosion Behavior of X7O Pipeline Steel Buried in Soils at Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    冯佃臣; 宋义全; 李涛; 李晓刚

    2011-01-01

    在内蒙古五个地区土壤现场将X70管线钢埋片两年.观察腐蚀产物的宏观和微观形貌,并用EDS和XRD分析腐蚀产物,计算X70管线钢在各试验站的两年腐蚀率.研究结果表明:经两年在五地区埋设的X70管线钢腐蚀率相差很大,其中巴盟地区腐蚀率最大为8.3 g/dm2.a.X70管线钢在内蒙古五地区土壤中腐蚀两年的腐蚀率小于一年的腐蚀率.腐蚀产物主要是Fe3O4和Fe3O4.%The corrosion of X70 pipeline steel in soils of five test sites at Inner Mongolia was studied by burying the steel specimens for two years. The corrosion morphology of the buried steel specimens as observed by SEM and the corrosion products were analyzed by using EDS and XRD.The results showed that the difference in corrosion rates of the steel was large in the five field soils.The maximum of corrosion rate 8.2924 g/dm2·d was observed for X70 buried at the test site at Bameng area. The corrosion rates of X70 for two years are lower than those for one year. The corrosion products were mainly consisted of Fe3O4 and FeO.

  15. Evolution of weld metal microstructure in shielded metal arc welding of X70 HSLA steel with cellulosic electrodes: A case study

    International Nuclear Information System (INIS)

    The microstructure of weld joint in X70 line pipe steel resulted from shielded metal arc welding with E6010 cellulosic electrodes is characterized using optical and electron microscopy. A range of ferritic morphologies have been identified ranging from polygonal inter- and intra-prior austenite grains allotriomorphic, idiomorphic ferrites to Widmanstätten, acicular and bainitic ferrites. Electron Backscatter Diffraction (EBSD) analysis using Image Quality (IQ) and Inverse Pole Figure (IPF) maps through superimposition of IQ and IPF maps and measurement of percentages of high and low angle grain boundaries was identified to assist in differentiation of acicular ferrite from Widmanstätten and bainitic ferrite morphologies. In addition two types of pearlitic structures were identified. There was no martensite detected in this weld structure. The morphology, size and chemistry of non-metallic inclusions are also discussed briefly. - Highlights: • Application of EBSD reveals orientation relationships in a range of phases for shielded metal arc welding of HSLA steel. • Nucleation sites of various ferrite morphologies identified • Formation of upper and lower bainite and their morphologies

  16. Evolution of weld metal microstructure in shielded metal arc welding of X70 HSLA steel with cellulosic electrodes: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Ghomashchi, Reza, E-mail: reza.ghomashchi@adelaide.edu.au; Costin, Walter; Kurji, Rahim

    2015-09-15

    The microstructure of weld joint in X70 line pipe steel resulted from shielded metal arc welding with E6010 cellulosic electrodes is characterized using optical and electron microscopy. A range of ferritic morphologies have been identified ranging from polygonal inter- and intra-prior austenite grains allotriomorphic, idiomorphic ferrites to Widmanstätten, acicular and bainitic ferrites. Electron Backscatter Diffraction (EBSD) analysis using Image Quality (IQ) and Inverse Pole Figure (IPF) maps through superimposition of IQ and IPF maps and measurement of percentages of high and low angle grain boundaries was identified to assist in differentiation of acicular ferrite from Widmanstätten and bainitic ferrite morphologies. In addition two types of pearlitic structures were identified. There was no martensite detected in this weld structure. The morphology, size and chemistry of non-metallic inclusions are also discussed briefly. - Highlights: • Application of EBSD reveals orientation relationships in a range of phases for shielded metal arc welding of HSLA steel. • Nucleation sites of various ferrite morphologies identified • Formation of upper and lower bainite and their morphologies.

  17. Study of phase transformations In API 5L X80 Steel in order to increase its fracture toughness

    OpenAIRE

    Igor Rafael Vilarouco Pedrosa; Renato Soares de Castro; Yogendra Prasad Yadava; Ricardo Artur Sanguinetti Ferreira

    2013-01-01

    Phase transformations in API 5L X80 steel were studied in different thermomechanical sequences with a view to increasing the fracture toughness of this steel. Dilatometry tests performed on the quenched steel detected a phase transformation occurred, during heating, in the temperature range 593-618 K. This phase transformation was identified as the dissolution of M-A islands. Based on preliminary dilatometric tests, ten thermal and thermomechanical treatments were performed on X80 steel sampl...

  18. Study of phase transformations In API 5L X80 Steel in order to increase its fracture toughness

    Directory of Open Access Journals (Sweden)

    Igor Rafael Vilarouco Pedrosa

    2013-04-01

    Full Text Available Phase transformations in API 5L X80 steel were studied in different thermomechanical sequences with a view to increasing the fracture toughness of this steel. Dilatometry tests performed on the quenched steel detected a phase transformation occurred, during heating, in the temperature range 593-618 K. This phase transformation was identified as the dissolution of M-A islands. Based on preliminary dilatometric tests, ten thermal and thermomechanical treatments were performed on X80 steel samples. Initially, the material was hot rolled and quenched and only quenched. On the material without deformation, aging was also performed at temperatures of 603, 673, 723, 773, 823 and 873 K. These treatments resulted in the formation of the acicular ferrite constituent, among others. Tensile tests showed that the aging treatments produced reductions in yield strength and increases in the elongation and toughness of X80 steel. All the treatments resulted in an increase in the tensile strength of steel.

  19. 热压缩变形参数对海底用 X70管线钢再结晶行为的影响%Effects of Hot Compression Deformation Parameters on Recrystallization Behavior of X70 Pipeline Steel Used in Submarine

    Institute of Scientific and Technical Information of China (English)

    王良塑; 贾书君; 刘清友; 项金钟

    2016-01-01

    采用热模拟试验机研究了应变速率为1 s-1时变形温度、变形量和变形后保温时间对海底用 X70管线钢再结晶行为的影响.结果表明:在变形量为25%的条件下,试验钢发生动态再结晶的变形温度为1000~1020℃,奥氏体晶粒可细化到33μm 左右;在变形温度为980℃的条件下,发生动态再结晶的变形量为25%~30%,当变形量达到30%时,再结晶基本完成,晶粒尺寸随变形量增大而减小;在变形温度为980℃、变形量为25%的条件下变形完成保温5 s后,试验钢开始发生静态再结晶,保温30 s 后静态再结晶基本完成,此时晶粒尺寸最小,为41μm.%Effects of deformation temperature, deformation and holding time after deformation on recrystallization behavior of X70 pipeline steel used in submarine were studied by thermal simulator.The results show that when deformation was 25%,dynamic recrystallization temperature of the tested steel was 1 000-1 020 ℃, austenite grain size could be refined to 33 μm.Under the condition of deformation temperatue of 980 ℃,dynamic recrystallization happened at deformation range of 25%-30%,dynamic recrystallization completed basically when deformation was 30%.Grain size decreased with the increase of deformation.When deformation temperature was 980 ℃,deformation was 25% and holding time was 5 s,tested steels started to static recrystallization,the static recrystallization completed basically after holding 30 s.At the moment,austenite grain size was minimum and up to 41 μm.

  20. Building P-S-N Curves of Weld Metal of Spiral Submerge-Arc Welded X70 Steel Pipe%螺旋埋弧焊接X70钢管焊缝金属P-S-N 曲线的建立

    Institute of Scientific and Technical Information of China (English)

    郑新侠; 雒设计

    2016-01-01

    通过对螺旋埋弧焊接X70钢管焊缝金属进行疲劳试验,得到了不同应力幅和应力比下的疲劳寿命数据,对疲劳寿命的概率分布进行了分析;依据当量疲劳寿命公式,获得疲劳抗力系数和当量疲劳极限,并对其概率分布进行分析,进而建立了焊缝金属的P-S-N 曲线,给出了指定存活率下的疲劳寿命曲线。结果表明:焊缝金属的疲劳寿命服从对数正态分布,疲劳抗力系数服从对数正态分布,以当量应力表示的疲劳极限服从正态分布。%Fatigue tests were conducted on weld metal specimens cut from spiral submerge-arc welded X70 steel pipe.Fatigue life data at different stress amplitudes and stress rations were obtained.The probability distribution of these data was analyzed.Based on the equivalent fatigue life formula,values of fatigue resistant coefficient and equivalent fatigue limit were obtained and their probability distribution were also analyzed.The P-S-N curves of weld metal were built up.Fatigue life curves at given survivability were given.The results show that fatigue life of weld metal follows 1ogarithmic normal distribution,fatigue resistant coefficient follows logarithmic distribution and equivalent fatigue limit follows normal distribution.

  1. Thermal Stability of Nanocrystalline Structure In X37CrMoV5-l Steel

    OpenAIRE

    Skołek E.; Marciniak S.; Świątnicki W.A.

    2015-01-01

    The aim of the study was to investigate the thermal stability of the nanostructure produced in X37CrMoV5-1 tool steel by austempering heat treatment consisted of austenitization and isothermal quenching at the range of the bainitic transformation. The nanostructure was composed of bainitic ferrite plates of nanometric thickness separated by thin layers of retained austenite. It was revealed, that the annealing at the temperature higher than temperature of austempering led to formation of ceme...

  2. Thermal Stability of Nanocrystalline Structure In X37CrMoV5-l Steel

    Directory of Open Access Journals (Sweden)

    Skołek E.

    2015-04-01

    Full Text Available The aim of the study was to investigate the thermal stability of the nanostructure produced in X37CrMoV5-1 tool steel by austempering heat treatment consisted of austenitization and isothermal quenching at the range of the bainitic transformation. The nanostructure was composed of bainitic ferrite plates of nanometric thickness separated by thin layers of retained austenite. It was revealed, that the annealing at the temperature higher than temperature of austempering led to formation of cementite precipitations. At the initial stage of annealing cementite precipitations occurred in the interfaces between ferritic bainite and austenite. With increasing temperature of annealing, the volume fraction and size of cementite precipitations also increased. Simultaneously fine spherical Fe7C3 carbides appeared. At the highest annealing temperature the large, spherical Fe7C3 carbides as well as cementite precipitates inside the ferrite grains were observed. Moreover the volume fraction of bainitic ferrite and of freshly formed martensite increased in steel as a result of retained austenite transformation during cooling down to room temperature.

  3. PROPERTIES OF SURFACE FILM FORMED ON X70 PIPELINE STEEL IN HCO3-/CO2-3 ENVIRONMENT%X70管线钢在HCO3-/CO2-3体系中表面膜性能研究

    Institute of Scientific and Technical Information of China (English)

    胡钢; 许淳淳; 池琳; 王紫色

    2005-01-01

    采用动电位扫描和交流阻抗方法研究了X70管线钢在0.5 mol/L Na2CO3+1 mol/L NaHCO3溶液中的阳极极化过程中的电化学行为,通过XPS和SEM对表面膜的组成和形貌进行了分析.结果表明,X70管线钢在阳极极化过程中分别于-600mV和-350 mV电位处出现2个阳极电流峰;-600mV时电极表面的反应阻力较小,表面膜主要由FeCO3、Fe2(OH)2CO3和FeOOH等化合物组成,表面膜上存在较多的微孔缺陷,处在一个不稳定状态,表面膜的保护性能较差;-350 mV时电极表面的反应电阻较大,表面膜主要由铁的氧化物Fe2O3和Fe3O4组成,表面膜具有较好的保护性能.

  4. Obtaining and analysis of results of fatigue and corrosion-fatigue in steel API 5L X60; Obtencao e analise de resultados de fadiga e corrosao-fadiga em aco API 5L X60

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Bruno Allison [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Silva, Antonio Almeida; Santos, Fabio Gualberto Chagas [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

    2008-07-01

    The corrosion process allied to the fatigue, due to repetitive efforts of several natures, is the main responsible for the damages in pipeline and offshore structures that results in the appears of located faults, and by the way can results in leaks and financial and environmental loss. This phenomenon calls corrosion-fatigue, however, it is very complex, and mainly, in what it concerns the form as this it develops in the structure. The objective of this work is to present some results of experimental fatigue tests and corrosion-fatigue accomplished with specimen that the material originated a pipeline steel API 5L X60. The tests developed in a machine which could test until 12 specimens per time. For test of corrosion-fatigue was used a cell-of-corrosion especially projected, in this way simulated an aggressive environmental condition in a corrosion conditions. With the results of tests, was possible estimate the fatigue limits of the specimen when submitted to the repeated flexing, and compare it with evaluate corrosion-fatigue graphs, that as the literature comes moved down of the curve, in relation to the fatigue curve. (author)

  5. The Effect of Temperature and Acid Gas Loading on Corrosion Behavior of API 5L X52 Carbon Steel in Amine Unit

    Science.gov (United States)

    Javidi, M.; Lalehparvar, M. M.; Ghassemi, A.

    2016-05-01

    The effect of temperature and H2S concentration on amine corrosion of API 5L X52 carbon steel in a CO2-saturated 25 wt.% diethanolamine solution was investigated via electrochemical techniques. It was found that increase in temperature from 25 to 80 °C resulted in severe increase in corrosion rate from 0.88 to 16.24 mpy due to increase in degradation rate of amine. Also, it was concluded that increase in H2S concentration led to increase in corrosion rate because of formation of more heat stable amine salts. The effect of temperature on corrosion rate was more significant than acid gas loading.

  6. Welding technique and quality of large diameter X70 line pipe for gas transmission of China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    X70 grade large diameter line pipe with helical and longitudinal seam SAW was developed and used in West-East Pipeline Project of Petrochina. The operation pressure of the pipeline was designed as 10 MPa, with diameter of 1016 mm OD. This project represents the first high-pressure, large diameter and high strength grade gas pipeline in China. All the factors affecting the safety of the pipeline shall be considered. The welds quality of line pipe is very important for safety of the pipeline. Acicular ferrite type X70 grade pipeline steel was adopted for the base material. The welds performances of X70 line pipes with 1016mm OD and 14.6-21.0 mm WT has reached a very high level, especially of low temperature Charpy V impact toughness of welds metal. Welding technique and quality status of X70 line pipe of China are investigated in this paper.

  7. X70管线钢在CO2-3/HCO-3体系中表面膜性能研究%Properties of Surface Film on XT0 Pipeline Steel in CO2-3/HCO-3 Environment

    Institute of Scientific and Technical Information of China (English)

    胡钢; 许淳淳

    2005-01-01

    The electrochemical behavior of X70 pipeline steel in (0.5 mol· L-1 Na2CO3+1 mol· L-1 NaHCO3)solution was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to analyze the composition and microstructure of the surface film. The results showed that there were two anodic peaks at -600 mV and -350 mV.The surface film formed at -600 mV mainly consisted of ferrous carbonates and ferrous hydroxycarbonates. It had a small reaction resistance. It was metastable and possessed poor protective property. Numerous pits and microcracks existed on the film, which could be the active paths for the initiation of stress corrosion cracking. The surface film formed at -350 mV, mainly consisted of ferric oxides. It has high reaction resistance and offered good protection for the substrate.

  8. Research and Development of X70 with an Acicular Ferrite Microstructure for West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    ZhengLei; GaoShan

    2004-01-01

    It is introduced in this paper that a high strength and high toughness X70 pipeline steel with an ultra-low acicular ferrite microstructure has been researched and developed at Baosteel according to the requirements of the West-East Gas Pipeline(WEGTP) project. The developed steel has higher strength, higher toughness, lower ductile-brittle transition temperature and higher dynamic tear-resistance than the conventional X70 with ferrite and pearlite microstructure. The excellent properties of the steel are benefited from ultralow carbon acicular ferrite consisting of interaction of very fine precipitated particles and high-density dislocation. And the steel has been applied on the WEGTP in China.

  9. Numerical Evaluation of Temperature Field and Residual Stresses in an API 5L X80 Steel Welded Joint Using the Finite Element Method

    Directory of Open Access Journals (Sweden)

    Jailson A. Da Nóbrega

    2016-01-01

    Full Text Available Metallic materials undergo many metallurgical changes when subjected to welding thermal cycles, and these changes have a considerable influence on the thermo-mechanical properties of welded structures. One method for evaluating the welding thermal cycle variables, while still in the project phase, would be simulation using computational methods. This paper presents an evaluation of the temperature field and residual stresses in a multipass weld of API 5L X80 steel, which is extensively used in oil and gas industry, using the Finite Element Method (FEM. In the simulation, the following complex phenomena were considered: the variation in physical and mechanical properties of the material as a function of the temperature, welding speed and convection and radiation mechanisms. Additionally, in order to characterize a multipass weld using the Gas Tungsten Arc Welding process for the root pass and the Shielded Metal Arc Welding process for the filling passes, the analytical heat source proposed by Goldak and Chakravarti was used. In addition, we were able to analyze the influence of the mesh refinement in the simulation results. The findings indicated a significant variation of about 50% in the peak temperature values. Furthermore, changes were observed in terms of the level and profile of the welded joint residual stresses when more than one welding pass was considered.

  10. Latest developments in mechanical properties and metallurgical features of high strength line pipe steels

    OpenAIRE

    Belato Rosado, Diego; De Waele, Wim; Vanderschueren, Dirk; Hertelé, Stijn

    2013-01-01

    In response to the increasing demand to improve both transportation efficiency and performance, the steel pipe industry has conducted extensive efforts to develop line pipe steel grades with superior metallurgical and mechanical (strength, toughness and ductility) properties in order to allow exploitation in hostile environments. This paper aims to give an overview of recent developments of high strength pipe steel grades as API 5L X70 and beyond, providing a detailed understanding of the con...

  11. Comportamiento de Laminaciones Coplanares y No Coplanares en Acero API5L X52 Simuladas mediante Elementos Finitos Behavior of Coplanar and Non-Coplanar Laminations in API5L X52 Steel Simulated by Finite Elements

    Directory of Open Access Journals (Sweden)

    Alberto Servin

    2009-01-01

    Full Text Available Se determina el comportamiento mecánico de laminaciones simples y escalonadas modeladas por elementos finitos en condiciones no lineales de esfuerzo-deformación, para comprender la secuencia de la interacción de los campos de esfuerzos en los extremos de la grietas. Se estableció una matriz de simulación variando la extensión circunferencial de las laminaciones, con espesor del tubo de 610mm de diámetro, con separación vertical y horizontal para el caso de laminaciones escalonadas. Se determino la función de distribución de esfuerzos en la región de las laminaciones en función de la presión en la grieta y en el tubo. Se estableció la presión que origina alcanzar la cedencia y resistencia ultima del material API5L X52, determinando que las laminaciones simples cuya extensión circunferencial va de 24 a 127 mm, soportan 50% más de presión de cedencia que las laminaciones escalonadas, y el 100% más de presión máxima permisible. Basados en la graficas presión versus radio de las laminaciones se concluye que las laminaciones no coplanares representan mayor riesgo de agrietamiento en una tubería.The mechanical behavior of the coplanar and non coplanar laminations by finite element using non lineal material conditions was determined, with the purpose of knowing the interaction sequence of the stress fields in the crack tips. The analysis includes a matrix simulation considering the circumferential length lamination, wall thickness of the pipe 610mm diameter, with vertical and horizontal distance for non coplanar laminations. The stress distribution in the laminations regions as a function of the internal pressures in the cracks and pipe were determined. The simulations done allowed defining the yield and the strength pressure that reach the mechanical properties of the API 5L X52. It was found that coplanar laminations with 24 at 127mm of circumferential length resist 50% more yield pressure than the non coplanar laminations and

  12. Short-term corrosion behavior of Q235 steel and XT0 pipeline steel in gray desert soil in North America%Q235钢和X70管线钢在北美山地灰钙土中的短期腐蚀行为

    Institute of Scientific and Technical Information of China (English)

    刘智勇; 王力伟; 杜翠薇; 王福明; 弓爱君; 李晓刚; Frank Cheng

    2013-01-01

    通过腐蚀失重速率试验、腐蚀形貌特征的扫描电镜观察和X射线衍射分析以及土壤理化性质分析等手段研究了国产Q235钢和X70管线钢在加拿大中南部的山地灰钙土中实地埋样试验一年后的短期腐蚀行为特征.结果发现Q235钢和X70钢的平均腐蚀速率和最大点蚀深度均比较接近,但Q235钢点蚀密度明显高于X70钢;两种钢的腐蚀产物成分类似,均为FeOOH、Fe3O4和Fe2O3的复杂混合物,腐蚀产物层不致密,存在明显的裂纹;两种钢表层土壤中均发现较多的硫酸盐还原菌、硫化菌和异养菌,这些菌群的共同作用能够加速腐蚀产物层下局部腐蚀的发生.

  13. Development of X70MS Grade Acid-resistance SAWL Pipe%抗酸性X70MS直缝埋弧焊管的研制

    Institute of Scientific and Technical Information of China (English)

    黄晓辉; 毕宗岳; 牛辉; 张世涛; 牛爱军; 吴佩军; 陈长青

    2014-01-01

    采用低C、低Mn、合金化设计和超洁净化冶炼制造的X70MS抗酸性钢板,通过控制焊接接头硬度、焊接热输入以及钢管残余应力等,开发制造出了X70MS抗酸性直缝埋弧焊管,并对焊管管体和焊缝组织性能进行了研究。结果表明,管体和焊缝的硬度均小于250HV10,0℃下母材冲击功大于410 J,焊接接头冲击功大于168 J;按照NACE-0284标准进行HIC测试,管母和焊接接头裂纹敏感率(CSR)、裂纹长度率(CLR)及裂纹厚度率(CTR)均为0;按照NACE-0177标准进行SSCC测试,采用A溶液,在72% ReL及90% ReL载荷下,管母和焊接接头均未出现断裂,管材表现出良好的力学性能和耐酸性。%The X70MS grade acid-resistance steel plate was produced by using the technology of low carbon, low manganese, microalloying design and clean smelting. By controlling the hardness of welded joints, welding heat input and the residual stress of steel pipe, the X70MS grade acid-resistance SAWL pipe was developed. Test results showed that the hardness of pipe body and weld both are less than 250 HV10. Under 0℃, the impact energy of base metal is greater than 410 J, and the impact energy of welded joint is greater than 168 J. The HIC tests were conducted in accordance with the NACE-0284 standard, the cracking sensitivity (CSR) of base metal and welded joints, the crack length ratio (CLR), and the crack thickness ratio (CTR) are all zero;The SSCC tests were conducted in accordance with NACE-0177 standard by using A solution under 72% ReL and 90% ReL loading, the fracture did not appear in base metal and welded joints, the pipes showed good mechanical properties and acid resistance.

  14. Effect of the welding process on the microstructure and microhardness of API 5L X80 steel welded joint used for oil transportation pipeline; Efeito do processo de soldagem sobre a microestrutura e a microdureza de juntas soldadas de aco API 5L X80 usado em tubulacoes para transporte de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Alves, R.T.P.; Albuquerque, S.F. [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Maciel, T.M.; Almeida, D.M.; Santos, M.A.

    2008-07-01

    This study had as objective to evaluate the microstructure and microhardness of API 5L X80 steel welded joints, used for pipelines to transport oil and gas, using the Shield Metal Arc Welding process with pre- heating temperature of 200 deg C and 400 deg C and the AWS E8010G electrode as filler metal. For this, besides the microhardness of the welded joint, the weld metals percentiles of micro-constituents and of columnar and regenerated grains and the medium size and extension of the heat affected zone were evaluated. The percentage of acicular ferrite in weld metal ranged from 13% to 33% which generated values of microhardness from 114 HV to 309 HV. (author)

  15. Caracterización de Revestimientos de Niobio formados por Aspersión Térmica a Plasma sobre Acero API 5l X65 Characterization of Niobium Coatings obtained by Plasma Spray Thermal Substrate on Steel API 5l X651

    Directory of Open Access Journals (Sweden)

    José F Matos

    2012-01-01

    Full Text Available Se evaluó la morfología y el comportamiento electroquímico del revestimiento de niobio obtenido por el proceso de aspersión térmica a plasma en substrato de acero API 5L X65. El revestimiento con niobio se realizó con una corriente eléctrica de 500 A, flujo de polvo metálico de niobio de 15 g/min y gas de argón de 2.0 L/min. La preparación superficial del substrato se realiza con pre-calentamiento y limpieza a presión con abrasivo de alúmina. La morfología del revestimiento fue analizada por microscopía electrónica de barrido (MEB, la rugosidad de la superficie se evaluó por perfilometría, la dureza por micro-dureza Vickers y la adherencia por ensayado de doblado a 180°. La resistencia a la corrosión del revestimiento se determinó mediante el ensayo de polarización en una solución de NaVl 3,5%. A partir de los resultados obtenidos fue posible verificar que el revestimiento presentó fisuras y poros entre las placas rociadas además de una dureza elevada en relación al substrato y adherencia no adecuada. Aún así los valores de densidad de corriente desarrollados por el sistema en comparación al acero revestido se redujeron.The morphology and electrochemical behavior of niobium coating obtained by thermal plasma spray process on a substrate of steel API 5L X65 was evaluated. The coating was obtained, using electrical current of 500 A, 15 g/min of powder and 2.0 L/min of argon gas. The preparation of the substrate surface was performed with preheating and abrasive blasting with alumina. After thermal spraying, the morphology of the coating was analyzed by scanning electron microscopy (SEM, while the surface roughness was evaluated by profilometry, hardness by Vickers microhardness test and adhesion by bending at 180 °. The corrosion resistance of the coating was evaluated from the polarization test in 3.5% NaVl solution. The results show that the coating presented cracking and lack of padding between the plates sprayed

  16. Influence of regenerative heat treatment on structure and properties of G20CrMo2 - 5 (L20HM cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2008-03-01

    Full Text Available Thc papcr prcscnts rcsuSts or rcscarch on thc influence of rcgcncratic hcat treatment on thc structurc and propcrtics [hardncss. impactcncrgy or L2O11M cnst stccl. Invcstipatcd material was taken from outer fmmc of a turbinc which was scrviccd for t 67 424 hours a! thctcmpcrauirc or 535 "C and prcssurc or 12.75 MPa. In psi-operating condition ~hicnv cstigntcd cast steel was cl~aracteri~cbdy low impactcncrpy of II I ant1 hart3ncss of 139HV30. Analysis uF the irlflue~~uuel ;lustcniriz;~ti on pariimctcrs (tcrnpcr;lturc and lime has rcvealcd rhntat thc tcinpcr;~turcr angc o f 895 + 955 "C (i-e. h3 - +I IO + 70 "C.fo r both 3 and 5 hours of holtl timc. rhc ohtaincd grain sizc amounls to 20+ 2511m. I has hccn pmved that tempcred bainitic-rcrri~ica nd remit ic-hainiric-pearlit ic stn~cturco f thc invcstigatcd cast stccl msurcs highimpact cncrgy, i.c. KV > 1001. as well a5 hardncss. i.e. 11Y30. just at thc tcrnpcmturc of OXl "C. 'I'crnpcmliirc or 7110 "C causcs i'~tnhcrincrclrsc of impact cncrgy along with a slight dccrcasc of hardncss. Morcovcr. it has hccn concludd that nppl ying oS under-annealinginstcad or tcmpcring. nflcr standardizalion. guarantees scquircd impact cncrgy of KY r 271.

  17. Research on the Non-metallic Inclusion in X70 Pipeline Cast Slab%X70管线钢铸坯中非金属夹杂物的研究

    Institute of Scientific and Technical Information of China (English)

    吴雨晨; 李俊国; 闫小林; 李守章; 曾亚南

    2009-01-01

    利用大样电解、金相观测、扫描电镜(SEM)和电子探针(EPMA)等手段,对X70管线钢铸坯中夹杂物的数量、粒径、形貌及组分进行了研究.结果表明:X70管线钢铸坯中夹杂物数量较多,粒径较大,且多为复合夹杂.针对大型夹杂物中硫化物、氧化物、硅铝酸盐和钙铝酸盐复合夹杂的特点,分析了铸坯中夹杂物的主要来源.%Utilizing the methods of sample-electrolysing, metallographic observation, SEM and EPMA, the quantity, dimension, morphologies and composition of non-metallic inclusions in X70 pipeline steel cast slab were investigated. It was suggested that there were larger amount of inclusions with larger diam-eter in the cast slab. Most of these inclusions were complex, such as sulfide, oxide, silicon aluminates and calcium aluminates inclusions. According to the characteristics of inclusions in the east slab, the ma-jor sources of different inclusions were analyzed and explored.

  18. X70M大壁厚螺旋埋弧焊管丁字焊缝工艺性能研究%Investigation on the Technological Properties of X70M Thick Wall SAWH Pipe T-shape Weld

    Institute of Scientific and Technical Information of China (English)

    蒋永峰; 王伟; 冯宗泽; 陆建刚; 任超

    2016-01-01

    X70M大壁厚螺旋埋弧焊管丁字焊缝焊接接头强度过高,经过成型器反变形易产生层状撕裂,焊缝热影响区温度过高易使焊缝组织产生脆化现象,为了确保X70M大壁厚螺旋埋弧焊管丁字焊缝焊接接头的各项性能指标,采用H08D焊丝与SJ101G焊剂匹配进行工艺试验,焊接过程中严格控制层间温度、减小焊接热输入及焊后热处理形式,通过试验得出了合理的焊接工艺。试验结果表明,按该工艺所焊试件的各项性能指标均达到API SPEC 5L PSL2标准及客户技术条件,采用此工艺已成功地生产了数万吨尼日利亚输油管线用管,效果良好。%If the welded joint strength of X70M thick wall SAWH pipe is too high, it is easy to generate backward deformation and lamellar tearing when pass through the forming machine, embrittlement phenomenon easily happen caused by too high HAZ temperature. In order to ensure the performance index of X70M thick wall SAWH pipe T-shape weld welded joints, using H08D welding wire matching with SJ101G flux to carry out process test, during the welding process strictly controlled interpass temperature, reduced the welding heat input and the form of heat treatment after welding, the reasonable welding process was obtained through experiments. The test result showed that all performance indexes of specimen by adopting the above process reach the standard API SPEC 5L PSL2 and customer technical conditions, it successfully produced tens of thousands of oil pipeline in Nigeria by adopting this technology, and the effect is good.

  19. Avaliação da microestrutura e propriedades mecânicas de metais de solda obtidos por processos de soldagem manual e automatizado utilizado na soldagem de aço API 5L X80 Evaluation of microstructure and mechanical properties of weld metals obtained by manual and automated welding process used in the welding of API 5L X80 steel

    Directory of Open Access Journals (Sweden)

    Siderley Fernandes Albuquerque

    2011-12-01

    Full Text Available O objetivo do trabalho foi avaliar as características da zona termicamente afetada (ZTA e a microestrutura e propriedades mecânicas de metais de solda de juntas soldadas do aço API 5L X80, obtidos para quatro diferentes procedimentos de soldagem utilizando processos manuais e automatizados. Para isto, chapas do referido aço foram soldadas por processo manual ao Arco Elétrico com Eletrodo Revestido (SMAW, utilizando 473 e 673 K como temperaturas de interpasses e o eletrodo celulósico AWS E8010-G como consumível; por processo ao Arco Elétrico com Arame Tubular (FCAW robotizado, utilizando o arame AWS E71T- 1C como metal de adição e argônio com 25%CO2 como gás de proteção; por processo a Arco Elétrico com Eletrodo de Tungstênio (GTAW mecanizado na raiz da solda, usando o arame ER70S-3 e argônio como gás de proteção. As análises microestruturais foram relacionadas com os resultados de ensaios de impacto Charpy nos metais de solda e com os perfis de microdureza Vickers ao longo da junta soldada. Os resultados indicaram maiores percentuais de Ferrita Acicular e maiores valores de resistência ao impacto nos metais de solda e uma menor extensão e granulometria da ZTA, associado ao procedimento de soldagem utilizando processo automatizado com maior velocidade de soldagem.The objective of this work was to evaluate the heat affected zone characteristics and weld metals microstructure and mechanical properties of API 5L X80 steel welded joints, obtained for four different welding procedures using manual and automated processes. For this, plates of this steel were welded by manual Shielded Metal Arc Welding (SMAW process with interpasses temperatures of 473 e 673 K, and using AWS E8010-G electrode as filler metals; robotized Flux Cored Arc Welding (FCAW process, using AWS E71T-1C wire and Ar25%CO2 as consumable and mechanized Gas Tungsten Arc Welding (GTAW process, for the root pass using AWS ER70S-3 and Ar as consumable .The

  20. Caracterización de Revestimientos de Niobio formados por Aspersión Térmica a Plasma sobre Acero API 5l X65 Characterization of Niobium Coatings obtained by Plasma Spray Thermal Substrate on Steel API 5l X651

    OpenAIRE

    José F Matos; Felipe P Motta; Ester S Rieder; Célia F. Malfatti

    2012-01-01

    Se evaluó la morfología y el comportamiento electroquímico del revestimiento de niobio obtenido por el proceso de aspersión térmica a plasma en substrato de acero API 5L X65. El revestimiento con niobio se realizó con una corriente eléctrica de 500 A, flujo de polvo metálico de niobio de 15 g/min y gas de argón de 2.0 L/min. La preparación superficial del substrato se realiza con pre-calentamiento y limpieza a presión con abrasivo de alúmina. La morfología del revestimiento fue analizada por ...

  1. Influence of cooling conditions on X70 pipeline steel in-service welding HAZ

    Institute of Scientific and Technical Information of China (English)

    Jin Haicheng; Wang Yong; Han Bin; Chen Yuhua

    2006-01-01

    The chamber device was designed and set up to simulate the in-service welding. The results show: the ts/5, t8/3 and inner wall peak temperature Tp decrease with the cooling rate increases. The welding energy is carried off by flowing medium,the cooling rate increases, and many unbalanced microstructures such as granular bainite, martensite and M-A generate; it worsens the properties of HAZ. Under air-cooling, the cooling rate is slow, the austenite grain grows obviously , the lath ferrite crosses the whole austenite, and it causes the hardness value is also big. The change of HAZ width is not obvious with the increase of cooling rate; and burn-through is not susceptible to the cooling rate. The quench microstructures increase and the hydrogen does not outflow from the HAZ easily when increase the cooling rate, so the susceptibility of hydrogen cracking increases.

  2. CO/sub 2/ corrosion of C-steel and 13Cr-steel in a particle laden fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, U.; Sydberger, T.

    1987-01-01

    Corrosion tests were carried out on C-steel (API 5L X70) and 13Cr steel (AISI 420) materials in a 3% NaCl solution containing sand particles (5000-9000 ppm) and saturated with CO/sub 2/ at defined partial pressure (0-0.3 MPa) and temperature (30-60/sup 0/C). The effect of residual O/sub 2/ content (10-1500 ppb) was further examined. Two flow geometries were studied: 1) undisturbed pipe flow and 2) submerged jet impinging (30-90/sup 0/) onto a flat plate. The effect of specimen surface treatment (shot-blasting or pickling) was examined with dry polished material as a reference. Weight-loss and electrochemical measurements were applied to determine average and instantaneous corrosion rates respectively. The results are discussed in relation to fluid flow conditions and the surface preparation/microstructure of materials tested.

  3. Steel

    International Nuclear Information System (INIS)

    Composition of age hardening steel, % : Fe - (12.0-12.4) Cr - (2-2.7) Ni (0.5-0.6) Ti - (1.0-1.2) Mn - (0.03 - 0.04) C having high values of magnetoelastic internal friction and mechanical properties as well as an ability to operate under the conditions of alternating loadings are proposed. Damping properties of the steel permit to improve labour conditions. Data for the above steel on internal friction, impact strength and tensile properties are given

  4. New calibration method for high and low triaxiality and validation on SENT specimens of API X70

    International Nuclear Information System (INIS)

    The determination of the exact mechanical properties of material is essential for an optimal and safe design of linepipes. It is especially important for the prevention of over-engineering and the reliable assessment of complex accidental loading, such as extreme bending due to loss of buoyancy of support, or abrupt ground movement. Currently, the focus of research in offshore deepwater installations and linepipes is towards pre-cracked structures with high triaxiality stress states and complex loading histories. At the same time, low triaxiality stress states must be correctly studied in order to represent shear dominated failure in pipes. A comprehensive experimental and numerical program was undertaken to determine the mechanical properties of the traditional API X70 grade of steel. The material was characterized for anisotropic plasticity, fracture initiation and uncracked ductility for various states of stress. The same material was also used for pre-cracked fracture toughness assessment. The experimental program included flat and round specimens. The first type of tests on flat butterfly-shaped, central hole, notched and circular disk specimens; were selected to address the low stress triaxiality range. Tests on round notched bar specimens and SENT fracture mechanics tests extended the characterization and verification process to higher stress triaxiality values. This program covered a wide range of stress conditions and demonstrated their effect on the material resistance to crack extension. Each test conducted was numerically simulated using solid finite element models, matching the exact geometric and loading history features. The numerical simulation provided information on the local stress and strain fields around the location of the potential or existing cracks. Based on the above hybrid experimental/numerical technique tailored for pipe applications, the MMC fracture model was calibrated. The model relates the material ductility not only to stress

  5. X70无缝酸性线管的形变淬火和回火工艺%Ausforming and tempering process of grade X70 sour service seamless pipeline

    Institute of Scientific and Technical Information of China (English)

    凌仲秋; 方剑; 周勇

    2012-01-01

    X70大口径厚壁无缝酸性线管形变淬火+回火处理工艺和普通淬火+回火工艺进行了对比分析。结果表明,形变淬火+回火工艺显著提高了强度,并具有良好的韧性,使产品的性能完全满足要求,同时还降低了生产成本。%Ausforming + tempering process and common quenching + tempering process were compared and analyzed for X70 sour service seamless pipeline with heavy diameter and thickness. The results show that the strength can be improved and the good toughness can be obtained, and then product property requirement can be completely satisfied by ausforming + tempering heat treatment. At the same time, production cost can be reduced.

  6. 几种焊接缺陷对X70管道环缝接头应力集中的影响%Influences on Stress Concentration of X70 Pipeline Circumferential Weld Joints of Several Welding Defects

    Institute of Scientific and Technical Information of China (English)

    李根; 张腾

    2014-01-01

    利用大型有限元软件ANSYS对在工作压力下带有咬边、凹坑、焊缝余高、错边等焊接缺陷的X70环缝管道进行了应力分析。分析结果显示,在咬边、凹坑、焊缝余高、错边焊接缺陷中,焊缝余高对受内压管道环焊缝的应力集中的影响最低,错边其次,咬边较为严重,凹坑最为严重;焊缝余高不影响X70管道接头静载强度,超过2 mm的错边量对环缝接头应力集中影响明显,咬边缺陷对X70管道环缝接头应力集中的影响大于错边,缺陷凹坑缺陷对环缝接头应力集中的影响随其三维尺寸增大而增大。%In this paper, the finite element analysis software ANSYS was used to carry out stress analysis on X70 pipeline under working pressure with welding defects, such as undercut, pit, weld reinforcement and misalignment. The results indicated that in the above defects, the influence on the weld reinforcement of stress concentration is the lowest, misalignment is the second, undercut is a bit severe, and the influence on pit is the most severe. The weld reinforcement does not affect the static load strength of X70 pipeline circumferential weld joints, and the influence of misalignment more than 2 mm on stress concentration is obvious. The influence of undercut on stress concentration is more than that of misalignment, and the influence of pit increases with three-dimensional size increasing.

  7. X70焊管焊接接头热影响区冲击试样缺口位置的探讨%Discussion on Impact Specimen Notch Position of X70 Welded Pipe Heat Affected Zone(HAZ)

    Institute of Scientific and Technical Information of China (English)

    王丽丽; 刘通; 王自信; 顾志乾

    2015-01-01

    In this article, it studied the distribution situation of metallographic structure, impact energy and shearing area of X70 SAWH pipe welded joint HAZ specimen in different Notch position, by adopting metallographic test and Charpy impact test. The results indicated that the values of impact energy value and shearing area are related with Notch position proportion in coarse grained region, fine grained region, part of the phase change zone and inside weld. The lower the proportion of inside weld is, the greater the impact energy and shearing area. After comprehensive analysis of test results and related standards, the determination method of X70 SAWH pipe welded joint HAZ specimen Notch position was obtained; the Notch axis of HAZ impact specimen should be in the junction of specimen upper surface and outside weld fusion line, and the distance from Impact test specimen edges to the outside weld edge of 1~2 mm is applicable.%通过金相试验、夏比冲击试验研究了X70螺旋埋弧焊管焊接接头热影响区试样不同缺口位置的金相组织、冲击功及剪切面积的分布情况。试验结果显示,冲击功和剪切面积的大小与缺口位置在粗晶区、细晶区、部分相变区和内焊缝所占的比例相关,内焊缝所占比例越低,冲击功和剪切面积越大。综合分析试验结果和相关标准,得出了X70焊管焊接接头热影响区试样缺口位置的确定方法,即热影响区冲击试样的缺口轴线应在试样上表面与外焊缝熔合线交界处,冲击试样边缘距外焊缝边缘1~2 mm为宜。

  8. X70钢级大径厚比热煨弯管制造工艺研究%Research on Manufacturing Technology for X70 Grade Large Diameter-thickness Ratio Hot Bending Bends

    Institute of Scientific and Technical Information of China (English)

    张海波; 彭立山; 白雷杰; 赵志伟; 刘旭; 巩忠旺

    2014-01-01

    针对X70钢级大径厚比热煨弯管的制造难点,合理改进了弯管机组设备,优化弯管成型工艺参数,精确测量和控制弯管煨制温度和速度,开发了一套完整的大径厚比弯管制造工艺,该工艺解决了大径厚比弯管成型后管体椭圆度超标和弯管综合力学性能差等问题。采用该工艺进行了单根和批量生产,产品符合伊拉克MOEP工程《弯管技术规格书》要求。%In this article,according to the manufacturing difficulties of X70 grade hot bending bends with large diameter-thickness ratio,it reasonably improved bends unit equipment,optimized bends forming process parameters,accurately measured and controlled the temperature and speed in bends forming process. A complete set of large diameter-thickness ratio bends manufacturing process was developed, it resolved some problems,including ovality of bends body exceeding the standard requirements,the comprehensive mechanic properties not good,and other manufacturing difficulties. It adopted the above manufacturing process to conduct single and bulk production, the products accord with the requirements of Iraq MOEP Project Technical Specification for Bending Bends.

  9. Delamination effects on fracture behavior of a pipeline steel: A numerical investigation of 3-D crack front fields and constraint

    International Nuclear Information System (INIS)

    This work addresses a numerical investigation of the crack front fields and effects of crack-tip constraint in conventional fracture specimens with prescribed transverse delamination cracks. One purpose of this study is to conduct a systematic evaluation of delamination effects in side-grooved and plane-sided C(T) and clamped SE(T) fracture specimens, which are commonly utilized in fracture toughness testing of pipeline steels. Another is to quantify the potential coupling influence of specimen geometry and delamination size on crack-tip constraint by means of the J−Q theory thereby providing valuable insight into the effect of delamination cracks on macroscopic fracture behavior in conventional fracture specimens. Laboratory testing of an API 5L X70 steel at room temperature provides the mechanical properties used in the numerical analysis incorporating delamination cracks with varying sizes. Nonlinear finite element analyses of very detailed 3-D finite element models of C(T) and clamped SE(T) fracture specimens for the API X70 pipeline steel enable assessing the effects of prescribed delamination cracks on the crack front fields and constraint with increased deformation levels as characterized by the J-integral. Overall, the present analyses reveal important features of 3-D crack front fields in fracture specimens with a crack-divider delamination that have a direct bearing on the often observed toughness increase in fracture testing of materials with through-thickness anisotropy in mechanical properties. - Highlights: • Extensive 3-D FE analysis of fracture specimens with crack-divider delamination cracks. • Formation of a crack-divider drastically changes the distribution of J over the crack front. • Even a small delamination crack promotes a pronounced stress redistribution. • Side-grooves do not change significantly delamination cracking effects on fracture behavior. • Delamination cracking effects in clamped SE(T) and C(T) geometries are

  10. Influence of thermal treatment on structure and corrosion properties of high manganese triplex steels

    Directory of Open Access Journals (Sweden)

    S. Lasek

    2013-10-01

    Full Text Available In this paper corrosion properties of X70MnAl28-9 TRIPLEX steel were tested after hot rolling and subsequent aging at 500 °C for 6, 30 and 60 min. and at 600 °C for the same times. For comparison related steels(X100MnAl28-12, X70Mn22, C20 were also used. The microstructure wascharacterized by light microscopy, SEM, energy disperse Xray microanalysis. The corrosion behaviour of steels wasexamined by light and scanning electron microscopy, electrochemical techniques (potenciodynamic polarization method, linear polarization, using NaCl and H2SO4 water solutions, salt spray test and gravimetric method. Aging has relatively small influence on corrosion resistance of X70MnAl28-9 steel. The localized corrosion in relation to structure and phases is discussed and compared in terms of dissolution, pitting and changes inchemical composition.

  11. Influence of thermal treatment on structure and corrosion properties of high manganese triplex steels

    OpenAIRE

    S. Lasek; Mazancová, E.

    2013-01-01

    In this paper corrosion properties of X70MnAl28-9 TRIPLEX steel were tested after hot rolling and subsequent aging at 500 °C for 6, 30 and 60 min. and at 600 °C for the same times. For comparison related steels(X100MnAl28-12, X70Mn22, C20) were also used. The microstructure wascharacterized by light microscopy, SEM, energy disperse Xray microanalysis. The corrosion behaviour of steels wasexamined by light and scanning electron microscopy, electrochemical techniques (potenciodynamic polarizati...

  12. 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)

  13. Elevated temperature mechanical properties of line pipe steels

    Science.gov (United States)

    Jacobs, Taylor Roth

    The effects of test temperature on the tensile properties of four line pipe steels were evaluated. The four materials include a ferrite-pearlite line pipe steel with a yield strength specification of 359 MPa (52 ksi) and three 485 MPa (70 ksi) yield strength acicular ferrite line pipe steels. Deformation behavior, ductility, strength, strain hardening rate, strain rate sensitivity, and fracture behavior were characterized at room temperature and in the temperature range of 200--350 °C, the potential operating range for steels used in oil production by the steam assisted gravity drainage process. Elevated temperature tensile testing was conducted on commercially produced as-received plates at engineering strain rates of 1.67 x 10 -4, 8.33 x 10-4, and 1.67 x 10-3 s-1. The acicular ferrite (X70) line pipe steels were also tested at elevated temperatures after aging at 200, 275, and 350 °C for 100 h under a tensile load of 419 MPa. The presence of serrated yielding depended on temperature and strain rate, and the upper bound of the temperature range where serrated yielding was observed was independent of microstructure between the ferrite-pearlite (X52) steel and the X70 steels. Serrated yielding was observed at intermediate temperatures and continuous plastic deformation was observed at room temperature and high temperatures. All steels exhibited a minimum in ductility as a function of temperature at testing conditions where serrated yielding was observed. At the higher temperatures (>275 °C) the X52 steel exhibited an increase in ductility with an increase in temperature and the X70 steels exhibited a maximum in ductility as a function of temperature. All steels exhibited a maximum in flow strength and average strain hardening rate as a function of temperature. The X52 steel exhibited maxima in flow strength and average strain hardening rate at lower temperatures than observed for the X70 steels. For all steels, the temperature where the maximum in both flow

  14. Hydrogen-related stress corrosion cracking in line pipe steel

    DEFF Research Database (Denmark)

    Nielsen, Lars Vendelbo

    1997-01-01

    A correlation between hydrogen concentration (C0) and the critical stress intensity factor for propagation of hydrogen-related cracks has been established by fracture mechanical testing of CT-specimens for the heat affected zone of an X-70 pipeline steel. This has been compared with field...... measurements of the hydrogen uptake by cathodically protected steel exposed in heavy clay and peat type soils....

  15. Rp0.2代替Rt0.5进行管线钢屈服强度测量的可行性研究%Study on the Feasibility of Using Rp0.2 Instead of Rt0.5 to Measure the Yield Strength of Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    吴金辉; 杨超; 荆松龙; 朱玉莲; 王树人; 王高峰; 李富强

    2012-01-01

    API SPEC 5L 《管线钢管规范》和ISO/DIS 3183 《石油天然气工业管线输送系统用钢管》明确提出了在钢级不高于X90时,使用Rt0.5作为材料的屈服强度;而当钢级高于X90时,Rp0.2则更适用于材料的屈服强度.但在管线钢及管线钢管实际的生产检验过程中,对于X65,X70和X80钢级的厚壁管线钢材料,由于受外在因素的影响,其测试结果有很大离散性,甚至已经严重影响到对结果的判定.探讨了采用Rp0.2代替Rt0.5进行管线钢屈服强度测量的可行性,为有效消除外在因素对屈服强度试验结果的影响提供理论依据.%In API SPEC 5L Specification/or Line Pipe and ISO/DIS3183 Petroleum and Natural Gas Industries-Steel Pipe for Pipeline Transportation Systems, it put forward Rt0.5 can be used as yield strength while pipeline steel grades =X90, and for grades>X90, Rp02 can be applied. However, the yield strength test results of X65, X70 and X80 grades pipeline steel with heavy thickness are seriously scattered due to the external factors; even it greatly affects judging result In this paper, the feasibility of using Rp02 instead of Rt05 to measure the yield strength of pipeline steel was studied, which provides a theoretical basis for eliminating the influence of external factors on the yield strength test results.

  16. Numerical simulation of dynamic brittle fracture of pipeline steel subjected to DWTT using XFEM-based cohesive segment technique

    Directory of Open Access Journals (Sweden)

    Reza H. Talemi

    2016-03-01

    Full Text Available In the past several numerical studies have addressed the ductile mode of fracture propagation. However, the brittle mode of pipeline failure has not received as much attention yet. The main objective of this study is to predict brittle fracture behaviour of API X70 pipeline steel by means of a numerical approach. To this end, the eXtended Finite Element Method (XFEM-based cohesive segment technique is used to model Drop Weight Tear Test (DWTT of X70 pipeline steel at -100°C. In this model the dynamic stress intensity factor and crack velocity are calculated at the crack tip at each step of crack propagation.

  17. Uma breve revisão histórica do desenvolvimento da soldagem dos aços API para tubulações A brief history review of development on API steels welding for pipeline

    Directory of Open Access Journals (Sweden)

    Jaime Casanova Soeiro Junior

    2013-06-01

    Full Text Available Este trabalho enfoca o desenvolvimento dos aços API para tubulações desde o aço API 5L X42, desenvolvido em 1948, através de laminação a quente seguida de tratamento térmico. Desde então foram feitos diferentes desenvolvimentos visando aumentar a resistência mecânica e a tenacidade, além de melhorar a soldabilidade. Entre eles, a adição de elementos de liga, produzindo os aços ARBL e a utilização de rotas de processamento termomecânico durante a laminação. Inicialmente a rota utilizada era a laminação a quente controlada (TMCR, com utilização de elemento microligante como Nb para os aços X60 e o conjunto Nb e V para os aços X65 e X70, associado a uma redução do teor de carbono. Posteriormente foi implantada a rota de fabricação do aço por laminação controlada seguida de resfriamento controlado (TMCP, com redução de carbono e adição de Nb e Ti para os aços X80, e adições de Mo, Nb, Be Ti para os X100. A redução do carbono foi motivada também para melhorar a sua soldabilidade e, por este motivo, estes aços são soldados por diferentes processos de soldagem, como o eletrodo revestido. Desenvolvimentos recentes com raiz feita com MAG-TC e enchimento com arame tubular tem dado resultados animadores.This paper is a brief history on the development of pipelines steels since the API 5L X42 steel, developed in 1948 by hot rolling followed by heat treatment. Subsequently different developments were made to increase the strength and toughness of these materials, and to improve their weldability. Among them, the addition of microalloying elements, producing HSLA steels and thermomechanical processing routes during hot rolling. Initially the route used was the controlled hot rolling (TMCR, together with microalloying element such as Nb for X60 steel and Nb plus V for X65 and X70 steels, associated with a reduction in carbon content. Later, the thermomechanical controlled process (TMCP manufacturing route was

  18. X70级φ1016 mm×17.5 mm天然气管道环焊缝缺陷剖析%Analysis on Circumferential Weld Defects of X70 φ 1 016 mm×17.5 mm Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    黄磊; 李记科; 王长安; 高建忠

    2013-01-01

    针对某天然气管道工程用X70级φ1 016 mm×17.5 mm焊管环焊缝焊接接头出现的缺陷,应用超声波检测和射线检测方法对缺陷进行了定位和定量检测,并通过金相分析、扫描电镜分析了缺陷中材料的性质.分析结果表明,此缺陷为第一次焊接过程中产生的焊渣在第二次补焊时未清理干净而产生的坡口未熔合.同时,分析了由于射线检测透照角度不同造成的射线底片影像异常现象.最后给出了焊接和无损检测过程中的一些合理化建议.%In this paper,aimed at the defects appeared in circumferential weld of X70 φ 1 016 mm×17.5 mm welded joint in some gas pipeline project,the positioning and quantitative detection for defects were carried out by ultrasonic inspection and X-ray inspection,and the material properties of defects were analyzed through metallographic analysis and SEM.The results showed that this kind of defect is incomplete fusion groove,which occurred in the first welding pass and didn't be cleaned completely after the second repair welding.At the same time,the abnormal phenomena of X-ray radiograph caused by different transillumination angle.Finally,some reasonable proposals in the process of welding and non-destructive test were put forward.

  19. Understanding mechanical property anisotropy in high strength niobium-microalloyed linepipe steels

    International Nuclear Information System (INIS)

    Thermo-mechanical processing of linepipe steels may result in anisotropy in mechanical properties, notably, yield strength and toughness, depending on the chemical composition and microstructure. These relationships are exceptionally important in spiral-welded pipe. Given the current interest in the development of high strength linepipe steels, we have examined in detail the mechanical property anisotropy phenomena using a combination of electron microscopy and crystallographic texture analysis in API L485 (X70) and API L555 (X80) steels. In this presentation, we describe the results of a study that has enhanced our understanding of the relationship between the microstructure and texture with anisotropy in mechanical properties. The microstructure of both X70 and X80 microalloyed linepipe steels as imaged via electron microscopy was similar and did not exhibit any significant anisotropy in the plane of the sheet. The microstructural constituents, polygonal ferrite and acicular ferrite (bainitic ferrite: ∼5–10% in X70 and ∼15–20% in X80) were also distributed uniformly throughout the volume of the specimens (0°, 45°, and 90° with respect to the rolling direction). The anisotropy in yield strength and Charpy impact toughness of X70-Nb and X80-Nb–Mo microalloyed linepipe steels was examined by using orientation distribution function analysis. The texture fibers of X70 and X80 microalloyed steels were similar but with significant differences in the intensity. Deformation textures mainly consisted of α-fiber (〈110〉//RD), γ-fiber (〈111〉//RD), and ε-fiber (〈110〉//TD). The major components of texture observed were {112}〈110〉, {332}〈113〉, {110}〈001〉, and {001}〈110〉 orientations. The observations suggested that the RD fiber centered at {112}〈110〉, {113}〈110〉, and {223}〈110〉 was responsible for the anisotropy in yield strength. The intensity of these texture components was higher in both X70 and X80 microalloyed steels

  20. Burst limit state reliability for fiber-wrapped steel pipe

    Energy Technology Data Exchange (ETDEWEB)

    Dann, Markus R. [University of Calgary (Canada); Maes, Marc A. [Blade Energy Partners Ltd. (Canada); Salama, Mamdouh M. [ConocoPhillips Company (United States)

    2010-07-01

    In the oil and gas sector, due to the increase in demand, pipeline projects are being developed in remote areas with harsh environments. High strength steel pipelines have been developed but due to their high cost and to low production capacity, the focus is now on dry fiber augmented steel technology pipelines (FAST-Pipe). The aim of this paper is to present a probabilistic mechanical burst limit state for such fiber wrapped pipelines. This model has been developed based on a large strain Cauchy stress formulation and has been used to perform a reliability comparison between an X80 pipe and an X70 FAST-Pipe. Results showed that the FAST-Pipe has more uncertainties than the high strength steel pipe and thus lower factors should be used in their design. This paper provided a probabilistic limit state model which can be used for both steel pipes and FAST-Pipe.

  1. Bax-PGAM5L-Drp1 complex is required for intrinsic apoptosis execution.

    Science.gov (United States)

    Xu, Wenjuan; Jing, Linlin; Wang, Quanshi; Lin, Chung-Chih; Chen, Xiaoting; Diao, Jianxin; Liu, Yuanliang; Sun, Xuegang

    2015-10-01

    Intrinsic apoptosis eliminates cells with damaged DNA and cells with dysregulated expression of oncogene. PGAM5, a member of the phosphoglycerate mutase family, has two splicing variants: PGAM5L (the long form) and PGAM5S (the short form). It has been well established that PGAM5 is at the convergent point of multiple necrosis pathways. However, the role of PGAM5 in intrinsic apoptosis is still controversial. Here we report that the PGAM5L, but not PGAM5S is a prerequisite for the activation of Bax and dephosphorylation of Drp1 in arenobufagin and staurosporine induced intrinsic apoptosis. Knockdown of PGAM5L inhibits the translocation of Bax to the mitochondria and reduces mitochondrial fission. The interaction between PGAM5L and Drp1 was observed in both arenobufagin and staurosporine treated HCT116 cells, but not in HCT116 Bax(-/-) cells. Bax transfection rescues the formation of the triplex in both arenobufagin and staurosporine stimulated HCT116 Bax(-/-) cells. Arenobufagin shows remarkable anti-cancer effects both in orthotropic and heterotropic CRC models and demonstrates less toxic effects as compared with that of cisplatin. Bax-PGAM5L-Drp1 complex is detected in arenobufagin and staurosporine treated CRC cells in vitro and in arenobufagin and cisplatin treated tumor in vivo as well. In summary, our results demonstrate that Bax-PGAM5L-Drp1 complex is required for intrinsic apoptosis execution. PMID:26356820

  2. Effects of Ultra Fast Cooling on Microstructure and Mechanical Properties of Pipeline Steels

    Science.gov (United States)

    Tian, Yong; Li, Qun; Wang, Zhao-dong; Wang, Guo-dong

    2015-09-01

    X70 (steel A) and X80 (steel B) pipeline steels were fabricated by ultra fast cooling (UFC). UFC processing improves not only ultimate tensile strength (UTS), yield strength (YS), yield ratio (YS/UTS), and total elongation of both steels, but also their Charpy absorbed energy ( A K) as well. The microstructures of both steels were all composed of quasi polygonal, acicular ferrite (AF), and granular bainite. MA islands (the mixtures of brittle martensite and residual austenite) are more finely dispersed in steel B, and the amount of AF in steel B is much more than that in steel A. The strength of steel B is higher than that of steel A. This is mainly attributed to the effect of the ferrite grain refinement which is resulted from UFC processing. The finely dispersed MA islands not only provide dispersion strengthening, but also reduce loss of impact properties to pipeline steels. UFC produces low-temperature transformation microstructures containing larger amounts of AFs. The presence of AF is a crucial factor in achieving desired mechanical properties for both steels. It is suggested that the toughness of the experimental steel increases with increasing the amount of AF.

  3. Large scale validation of the M5L lung CAD on heterogeneous CT datasets

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Torres, E., E-mail: Ernesto.Lopez.Torres@cern.ch, E-mail: cerello@to.infn.it [CEADEN, Havana 11300, Cuba and INFN, Sezione di Torino, Torino 10125 (Italy); Fiorina, E.; Pennazio, F.; Peroni, C. [Department of Physics, University of Torino, Torino 10125, Italy and INFN, Sezione di Torino, Torino 10125 (Italy); Saletta, M.; Cerello, P., E-mail: Ernesto.Lopez.Torres@cern.ch, E-mail: cerello@to.infn.it [INFN, Sezione di Torino, Torino 10125 (Italy); Camarlinghi, N.; Fantacci, M. E. [Department of Physics, University of Pisa, Pisa 56127, Italy and INFN, Sezione di Pisa, Pisa 56127 (Italy)

    2015-04-15

    Purpose: M5L, a fully automated computer-aided detection (CAD) system for the detection and segmentation of lung nodules in thoracic computed tomography (CT), is presented and validated on several image datasets. Methods: M5L is the combination of two independent subsystems, based on the Channeler Ant Model as a segmentation tool [lung channeler ant model (lungCAM)] and on the voxel-based neural approach. The lungCAM was upgraded with a scan equalization module and a new procedure to recover the nodules connected to other lung structures; its classification module, which makes use of a feed-forward neural network, is based of a small number of features (13), so as to minimize the risk of lacking generalization, which could be possible given the large difference between the size of the training and testing datasets, which contain 94 and 1019 CTs, respectively. The lungCAM (standalone) and M5L (combined) performance was extensively tested on 1043 CT scans from three independent datasets, including a detailed analysis of the full Lung Image Database Consortium/Image Database Resource Initiative database, which is not yet found in literature. Results: The lungCAM and M5L performance is consistent across the databases, with a sensitivity of about 70% and 80%, respectively, at eight false positive findings per scan, despite the variable annotation criteria and acquisition and reconstruction conditions. A reduced sensitivity is found for subtle nodules and ground glass opacities (GGO) structures. A comparison with other CAD systems is also presented. Conclusions: The M5L performance on a large and heterogeneous dataset is stable and satisfactory, although the development of a dedicated module for GGOs detection could further improve it, as well as an iterative optimization of the training procedure. The main aim of the present study was accomplished: M5L results do not deteriorate when increasing the dataset size, making it a candidate for supporting radiologists on large

  4. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...

  5. Steel Spring

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Tarnished Hebei Iron and Steel Group regains chance to shine A lthough it is too early to tell whether the steel-making sector has emerged [from its gloom, a big divide is openling between China’s large and small producers. While most of the marginal players are still reeling from a market contagion, steel titans like the Shanghai-based Baosteel

  6. KAYNAKLI API 5L X65 BORU HATTI ÇELİKLERİNİN KlRlLMA TOKLUGU

    Directory of Open Access Journals (Sweden)

    HÜSEYİN UZUN

    2002-06-01

    Full Text Available Petrol ve dogal gaz boru hatla rında ya ygın olarak kulla nıla n ve ta ndem tozaltı ka yna k metodu ile bir leşt irilen API 5L X65 d u al fa zlı çeliğin kırılma to lduğu tespit edilmiştir. Kırılma to lduğu, çentikli üç nokta kırılma tokluğu deneyi kulla nıla ra k belirlenmiştir. Çentik, hem kayna k dikişinin or tası na hem de ısının tesiri altında ki bölgesi (IT AB içerisinin içine gelecek şekilde aç ılarak deney uygula nmıştır. Her bir nurnuneye gerilim giderme ta vlaması uygul anarak, kırılma tokluğu değerler inin nasıl etkilendiği değerlendirilmiştir. Elde edilen sonuçlara göre, gerilim giderme ta vı uygula nmamış ve uygulanmış numunelerde, kaynak dikişin in kırılma to ld u ğ u , IT AB bölgesinin kırılma to lduğundan daha yüksek çıkmıştır. Anahtar Kelimeler - API 5L X65 çeliğinin kırılma tokluğu, spira l dikişli borular, ta ndem tozaltı kaynağı. Abstract -The fra cture toughness of API 5L X65 dual­phase steel welded by ta ndem submerged are welding process, which is used widely petrolenın and na tural gas pipelines, wa s investigated. The fra cture toughness values were obta ined using by three point bend fracture toughness test specimens. The notch was machined either in the center of w el d meta l or the heat affected zone (H AZ. It wa s employed stress relief annealing in order to inves tigate the effect heat treatment on the fra cture toughness va lues. The results show tha t the fracture toughness va lues of weld metal with both heat treatment and non-h eat treatment are higher than that of the heat affected zone. Keywords - Fracture toughness of API 5L X65 steel, sp ira ll y welded pipeline, tandem submerged are welding. ı. GİRİŞ Doğal gaz ve petrol taşıma borularında, sistemin emniyeti için API 5L standardına uygun sertifikalı borular tercih edilmektedir. Bu standarda göre, boyuna veya H. UZUN: Sakarya Üniversitesi, Teknik Eğitim Fak

  7. Effect of Celluclast 1.5L on the Physicochemical Characterization of Gold Kiwifruit Pectin

    Directory of Open Access Journals (Sweden)

    John A. Mawson

    2011-09-01

    Full Text Available The effects of Celluclast 1.5L concentration on the physicochemical characterization of gold kiwifruit pectin was evaluated. Varying the enzyme concentration affected the pectin yield and pectin physicochemical properties. The viscosity of extracted pectin was largely dependent on the enzyme concentration. Celluclast 1.5L with medium concentration exhibited the highest viscosity. Varying the enzyme concentration also influenced the molecular weight distribution. High molecular weight (Mw pectin (1.65 × 106 g/mol was obtained when the medium concentration was used. Overall, the study clearly reflects the importance of taking into consideration the amount of cellulytic enzyme added in order to determine the final quality of pectin.

  8. Steel Planning

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China releases a new plan for the iron and steel industry centered on industrial upgrades The new 12th Five-Year Plan (2011-15) for China’s iron and steel industry, recently released on the website of the Ministry of Industry and Information

  9. Effect of welding thermal cycles on the heat affected zone microstructure and toughness of multi-pass welded pipeline steels

    OpenAIRE

    Nuruddin, Ibrahim K.

    2012-01-01

    This research is aimed at understanding the effect of thermal cycles on the metallurgical and microstructural characteristics of the heat affected zone of a multi-pass pipeline weld. Continuous Cooling Transformation (CCT) diagrams of the pipeline steel grades studied (X65, X70 and X100) were generated using a thermo mechanical simulator (Gleeble 3500) and 10 mm diameter by 100 mm length samples. The volume change during phase transformation was studied by a dilatometer, this is to underst...

  10. NORMATIVE VALUES OF EQ-5D-5L FOR DIABETES PATIENTS FROM SPAIN.

    Science.gov (United States)

    Collado Mateo, Daniel; García Gordillo, Miguel A; Olivares, Pedro R; Adsuar, José C

    2015-10-01

    Introducción: la diabetes es una enfermedad metabólica que puede conllevar una reducción de la calidad de vida relacionada con la salud. El EQ-5D es un cuestionario genérico de calidad de vida relacionada con la salud basado en preferencias sociales. Este cuestionario ha sido muy utilizado en pacientes con diabetes. Objetivo: el objetivo del presente artículo es informar sobre los valores normativos del cuestionario EQ-5D-5L en personas españolas con diabetes. Métodos: se utilizaron datos de la Encuesta Española de Salud (2011/2012). Un total de 1.857 personas con diabetes participaron en la encuesta. La puntuación del EQ-5D-5L se ha reflejado en función del sexo, región (incluyendo las 17 comunidades autónomas y las 2 ciudades autónomas de España), y 8 grupos de edad. Resultados: la media del índice de utilidad para toda la muestra fue de 0,742. Esta fue mejor para hombres (0,826) que para mujeres (0,673). Resultados similares se observaron en la Escala Visual Analógica. El efecto techo fue mucho mayor en hombres (44,83%) que en mujeres (24,41%). Conclusiones: el presente estudio recoge datos normativos representativos del EQ-5D-5L en España de personas con diabetes.

  11. Comparing responsiveness of the EQ-5D-5L, EQ-5D-3L and EQ VAS in stroke patients

    NARCIS (Netherlands)

    D. Golicki (Dominik); M. Niewada (Maciej); A. Karlińska (Anna); J. Buczek (Julia); A. Kobayashi (Adam); M.F. Janssen (Mathieu); A.S. Pickard (Simon)

    2015-01-01

    textabstractAims: To date, evidence to support the construct validity of the EQ-5D-5L has primarily focused on cross-sectional data. The aims of this study were to examine the responsiveness of EQ-5D-5L in patients with stroke and to compare it with responsiveness of EQ-5D-3L and visual analogue sca

  12. The human CD5L/AIM-CD36 axis: A novel autophagy inducer in macrophages that modulates inflammatory responses.

    Science.gov (United States)

    Sanjurjo, Lucía; Amézaga, Núria; Aran, Gemma; Naranjo-Gómez, Mar; Arias, Lilibeth; Armengol, Carolina; Borràs, Francesc E; Sarrias, Maria-Rosa

    2015-01-01

    CD5L (CD5 molecule-like) is a secreted glycoprotein that participates in host response to bacterial infection. CD5L influences the monocyte inflammatory response to the bacterial surface molecules lipopolysaccharide (LPS) and lipoteichoic acid (LTA) by inhibiting TNF secretion. Here we studied the intracellular events that lead to macrophage TNF inhibition by human CD5L. To accomplish this goal, we performed functional analyses with human monocytic THP1 macrophages, as well as with peripheral blood monocytes. Inhibition of phosphatidylinositol 3-kinase (PtdIns3K) reversed the inhibitory effect of CD5L on TNF secretion. Among the various PtdIns3K isoforms, our results indicated that CD5L activates PtdIns3K (whose catalytic subunit is termed PIK3C3), a key modulator involved in autophagy. Further analysis revealed a concomitant enhancement of autophagy markers such as cellular LC3-II content, increased LC3 puncta, as well as LC3-LysoTracker Red colocalization. Moreover, electron microscopy showed an increased presence of cytosolic autophagosomes in THP1 macrophages overexpressing CD5L. Besides preventing TNF secretion, CD5L also inhibited IL1B and enhanced IL10 secretion. This macrophage anti-inflammatory pattern of CD5L was reverted upon silencing of autophagy protein ATG7 by siRNA transfection. Additional siRNA experiments in THP1 macrophages indicated that the induction of autophagy mechanisms by CD5L was achieved through cell-surface scavenger receptor CD36, a multiligand receptor expressed in a wide variety of cell types. Our data represent the first evidence that CD36 is involved in autophagy and point to a significant contribution of the CD5L-CD36 axis to the induction of macrophage autophagy.

  13. Study on the correlation of toughness with chemical composition and tensile test results in microalloyed API pipeline steels

    Directory of Open Access Journals (Sweden)

    Pouraliakbar H.

    2015-01-01

    Full Text Available In this investigation, an artificial neural network model with feed forward topology and back propagation algorithm was developed to predict the toughness (area underneath of stress-strain curve of high strength low alloy steels. The inputs of the neural network included the weight percentage of 15 alloying elements and the tensile test results such as yield strength, ultimate tensile strength and elongation. Developing the model, 118 different steels from API X52 to X70 grades were used. The developed model was validated with 26 other steels from the data set that were not used for the model development. Additionally, the model was also employed to predict the toughness of 26 newly tested steels. The predicted values were in very good agreement with the measured ones indicating that the developed model was very accurate and had the great ability for predicting the toughness of pipeline steels.

  14. Relationship between a novel polymorphism of the C5L2 gene and coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Ying-Ying Zheng

    Full Text Available BACKGROUND: C5L2 has been demonstrated to be a functional receptor of acylation-stimulating protein (ASP, which is a stimulator of triglyceride synthesis or glucose transport. However, little is known about the variations in the coding region of the C5L2 gene and their association with coronary artery disease (CAD. METHODOLOGY/PRINCIPAL FINDINGS: We identified a novel single nucleotide polymorphism (SNP, 698C>T (P233L, in exon 2 using a polymerase chain reaction direct-sequencing method. This nucleotide change causes the amino-acid order from proline to leucine at codon 233. We examined the role of this SNP for CAD using two independent case-control studies: one was in the Han population (492 CAD patients and 577 control subjects and the other was in the Uygur population (319 CAD patients and 554 control subjects. Heterozygote carriers of the 698CT genotype were more frequent among CAD patients than among controls not only in the Han population (7.3% versus 1.7% but also in the Uygur population (4.7% versus 1.6%. The odds ratio (OR for carriers of the 698CT genotype for CAD was 4.484 (95% confidence interval (CI: 2.197-9.174 in the Han group and 2.989 (95% CI: 1.292-6.909 in the Uygur population. After adjustment of confounding factors such as sex, age, smoking, alcohol consumption, hypertension, diabetes, as well as serum levels of triglyceride, total cholesterol, high-density lipoprotein, the difference remained significant in the Han group (P<0.001, OR = 6.604, 95% CI: 2.776-15.711 and in the Uygur group (P = 0.047, OR = 2.602, 95% CI: 1.015-6.671. CONCLUSION/SIGNIFICANCE: The 698CT genotype of C5L2 may be a genetic maker of CAD in the Han and Uygur population in western China.

  15. Alloyed steel

    International Nuclear Information System (INIS)

    The composition and properties are listed of alloyed steel for use in the manufacture of steam generators, collectors, spacers, emergency tanks, and other components of nuclear power plants. The steel consists of 0.08 to 0.11% w.w. C, 0.6 to 1.4% w.w. Mn, 0.35 to 0.6% w.w. Mo, 0.02 to 0.07% w.w. Al, 0.17 to 0.37% w.w. Si, 1.7 to 2.7% w.w. Ni, 0.03 to 0.07% w.w. V, 0.005 to 0.012% w.w. N, and the rest is Fe. The said steel showed a sufficiently low transition temperature between brittle and tough structures, a greater depth of hardenability, and better weldability than similar steels. (B.S.)

  16. Steel welding.

    OpenAIRE

    Kučera, Marek

    2011-01-01

    Topic of the thesis concerns the problem of steel welding. The aim was to give acomprehensive overview on the topic, describe the known methods, advantages and disadvantages of welding technology. The introductory part is focused on introducing the basics of the process required to produce high-quality connections. Chapter three offers an overview of known and used welding methods with thein brief description of the method. The next chapter describes steel as material suitable for welding....

  17. Application of Celluclast 1.5L in apple pectin extraction.

    Science.gov (United States)

    Wikiera, Agnieszka; Mika, Magdalena; Starzyńska-Janiszewska, Anna; Stodolak, Bożena

    2015-12-10

    Pectins were extracted from apple pomace with Celluclast 1.5L at a dose of 25, 50 and 75 μl per 1g of material. In obtained pectin, the galacturonic acid (GalA) content, the neutral sugars (NS) profile, the degree of methylation (DM) and acetylation (DAc), the molecular mass, protein, ash and polyphenol levels as well as antioxidant and antitumor activity were determined. The lowest dose of enzymatic preparation resulted in the yield of pectin isolation comparable with acidic treatment (15.3%). Application of higher dose caused further, almost 4% increase in polymer recovery. Enzymatically isolated pectin was characterised by larger molecular mass and contained more GalA of higher DM and DAc than polymer extracted with acid. It was also richer in protein and polyphenols, and had different NS profile, which resulted in higher antiradical activity as well as the ability to inhibit the proliferation and invasion of Caco-2 adenocarcinoma cells.

  18. 3.5L V6 EcoBoost - democratization of sustainable engine technology

    Energy Technology Data Exchange (ETDEWEB)

    Kapp, Daniel; Schamel, Andreas; Hinds, Brett; Weaver, Corey [Ford Motor Co., Dearborn, MI (United States)

    2008-07-01

    The North American automotive industry is presently facing the challenge of a recently signed energy bill increasing corporate average fuel economy standards to 35 mpg (6.7 L/km) by 2020, inclusive of cars and trucks. The passing of this bill is coincident with crude oil costs hovering in the $130USD / barrel range, retail gasoline costs in the $4USD / gallon range, and mounting evidence on CO2 emissions and global warming. Ford Motor Company has anticipated these trends, has invested in the development of fuel efficient engine technologies, and is now deploying these technologies in volume to deliver both a meaningful and sustainable response to the above challenges. Leading the deployment curve is a technology publically announced as EcoBoost, representing the application of direct fuel injection and turbocharging to an advanced gasoline engine. Ford has previously reported the fundamentals of this technology which enables a significant fuel economy improvement via engine downsizing, and a significant performance improvement via engine dynamic response. As applied to 14 and V6 engine architectures, Ford has announced plans to deploy up to 750,000 EcoBoost engines worldwide by 2013 CY, with first application in the form of a 3.5L V6 EcoBoost engine in the 2010 MY Lincoln MKS luxury sedan. This paper summaries the development of the 3.5L V6 EcoBoost engine and its associated as-installed systems. Combustion, fuel, boost, and power conversion systems are discussed in detail with emphasis on the efficiency and value of these systems which enable a singular engine design to be applied across a wide range of applications. Engine performance and fuel economy assessments are also discussed and compared to conventional gasoline engines. (orig.)

  19. 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.

  20. A new generation of ultra high strength steel pipelines

    International Nuclear Information System (INIS)

    For many years an increased demand for natural gas can be observed. Ultra high-strength pipelines with higher operating pressures and/or reduced wall thickness are a means to reduce transmission costs. Motivated by reduced investment costs (overcharge a few billion of dollars), tend towards the development of a new grade of pipeline steel with microalloying element for example Nb, that potentially lowers the total cost of long-distance gas pipelines by 5 - 15%. New long distance pipelines have budgets in excess of several billion dollars. This paper describes mechanical properties of new generation of pipelines steel with higher content of niobium and the influence the welding thermal cycles on the microstructure and brittle fracture resistance. The resistance to cold cracking has also been determined. It was found that the new steel has close properties to API X70 grade steels, but is cheaper in manufacturing and installation. The steel has been covered by the amended EN 10028-5 standard and proper modifications will also be made in other European standards. (author)

  1. Influencia del precalentamiento en las propiedades de uniones soldadas de acero API 5L-X80 soldadas con alambre tubular autoprotegido

    Directory of Open Access Journals (Sweden)

    Cooper, R.

    2004-08-01

    Full Text Available 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 (IG, 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 °C, 160 °C. These temperatures were maintained as interpass temperature. The filler metal E71T8-K6 with mechanical properties different from parent metal was used in undermatched 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.

    Este trabajo presenta un estudio sobre la caracterización de las propiedades mecánicas de uniones soldadas con alambre tubular autoprotegido, de acero API 5L-X80. En este sentido, se evalúa la influencia de la temperatura de precalentamiento, manteniendo el aporte de calor uniforme. Todas las uniones soldadas se realizaron en la posición plana (IG, con la antorcha fíja y la tubería girando. Se utilizó un tubo de 762 mm de diámetro exterior y 16 mm de espesor. Las soldaduras se aplicaron sobre una unión de tope con bisel en V simple, utilizando 6 pasadas, con tres niveles de temperatura de precalentamiento (ambiente, 100 °C y 160 °C. Estas temperaturas se mantuvieron como temperatura entre pasadas. El metal de aporte, del tipo E71T8-K6, se utilizó en la

  2. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    Even in our globalized world the notion of national economies remain incredibly strong, just as a considerable part of the literature on transnational governance and globalization continue to rely on a zero-sum perspective concerning the relationship between the national and the transnational. De...... of the European steel industry....

  3. Independent chromatin binding of ARGONAUTE4 and SPT5L/KTF1 mediates transcriptional gene silencing.

    Directory of Open Access Journals (Sweden)

    M Jordan Rowley

    2011-06-01

    Full Text Available Eukaryotic genomes contain significant amounts of transposons and repetitive DNA elements, which, if transcribed, can be detrimental to the organism. Expression of these elements is suppressed by establishment of repressive chromatin modifications. In Arabidopsis thaliana, they are silenced by the siRNA-mediated transcriptional gene silencing pathway where long non-coding RNAs (lncRNAs produced by RNA Polymerase V (Pol V guide ARGONAUTE4 (AGO4 to chromatin and attract enzymes that establish repressive chromatin modifications. It is unknown how chromatin modifying enzymes are recruited to chromatin. We show through chromatin immunoprecipitation (ChIP that SPT5L/KTF1, a silencing factor and a homolog of SPT5 elongation factors, binds chromatin at loci subject to transcriptional silencing. Chromatin binding of SPT5L/KTF1 occurs downstream of RNA Polymerase V, but independently from the presence of 24-nt siRNA. We also show that SPT5L/KTF1 and AGO4 are recruited to chromatin in parallel and independently of each other. As shown using methylation-sensitive restriction enzymes, binding of both AGO4 and SPT5L/KTF1 is required for DNA methylation and repressive histone modifications of several loci. We propose that the coordinate binding of SPT5L and AGO4 creates a platform for direct or indirect recruitment of chromatin modifying enzymes.

  4. API Spec5L(44版)关于材料及试验的变化%Changes of Materials and Tests in 44th Edition of Standard API Spec 5L

    Institute of Scientific and Technical Information of China (English)

    王德林; 同建辉; 孙宏; 崔明亮

    2011-01-01

    针对API Spec 5L(44版)标准,简要分析了API 5L(44版)标准对于材料与理化试验方面与前一版本的变化.新版API 5L标准相比以前版本更加精简,实际使用更方便,在理化试验方面细节上变化较大,在焊管的实际生产应用中应予以注意.

  5. Microstructure and Mechanism of Strengthening of Microalloyed Pipeline Steel: Ultra-Fast Cooling (UFC) Versus Laminar Cooling (LC)

    Science.gov (United States)

    Zhao, J.; Wang, X.; Hu, W.; Kang, J.; Yuan, G.; Di, H.; Misra, R. D. K.

    2016-06-01

    A novel thermo-mechanical controlled processing (TMCP) schedule involving ultra-fast cooling (UFC) technique was used to process X70 (420 MPa) microalloyed pipeline steel with high strength-high toughness combination. A relative comparison is made between microstructure and mechanical properties between conventionally processed (CP) and ultra-fast cooled (UFC) pipeline steels, together with differences in strengthening mechanisms with respect to both types of processes. UFC-processed steel exhibited best combination of strength and good toughness compared to the CP process. The microstructure of CP pipeline steel mainly consisted of acicular ferrite (AF), bainitic ferrite (BF), and dispersed secondary martensite/austenite (M/A) constituent and a small fraction of fine quasi-polygonal ferrite. In contrast, the microstructure of UFC-processed pipeline steel was predominantly composed of finer AF, BF, and dispersed M/A constituent. The primary strengthening mechanisms in UFC pipeline steel were grain size strengthening and dislocation strengthening with strength increment of ~277 and ~151 MPa, respectively. However, the strengthening contribution in CP steel was related to grain size strengthening, dislocation strengthening, and precipitation strengthening, and the corresponding strength increments were ~212, ~149 and ~86 MPa, respectively. The decrease in strength induced by reducing Nb and Cr in UFC pipeline steel was compensated by enhancing the contribution of grain size strengthening in the UFC process. In conclusion, cooling schedule of UFC combined with LC is a promising method for processing low-cost pipeline steels.

  6. Quality of life profile and psychometric properties of the EQ-5D-5L in HIV/AIDS patients

    Directory of Open Access Journals (Sweden)

    Tran Bach

    2012-11-01

    Full Text Available Abstract Objectives We assessed health-related quality of life (HRQOL, its associated factors, and examined measurement properties of the EuroQol - 5 Dimensions - 5 Levels (EQ-5D-5L in HIV/AIDS patients. Methods A cross-sectional multi-site survey was conducted in 1016 patients (age: 35.4 ± 7.0 years; 63.8% male in three epicenters of Vietnam. Internal consistency reliability, convergent validity, and discriminative validity of the EQ-5D-5L and a visual analogue scale (VAS were evaluated. Tobit censored regression models were used to identify predictors of HRQOL in HIV/AIDS patients. Results The mean EQ-5D-5L single index and VAS were 0.65 (95% Confidence Interval (CI = 0.63; 0.67 and 70.3 (95% CI = 69.2; 71.5. Cronbach’s alpha of five dimensions was 0.85. EQ-5D-5L has a good convergent validity with VAS (0.73. It discriminated patients at different HIV/AIDS stages, duration of ART, and CD4 cell count. Predictors of poorer HRQOL included being female, lower education level, unemployment, alcohol and drug use, CD4 Conclusion The EQ-5D-5L has good measurement properties in HIV/AIDS patients and holds potentials for monitoring ART outcomes. Integration of HRQOL measurement using EQ-5D-5L in HIV/AIDS clinical practice could be helpful for economic evaluation of HIV/AIDS interventions.

  7. Adhesions of extracellular surface-layer associated proteins in Lactobacillus M5-L and Q8-L.

    Science.gov (United States)

    Zhang, Yingchun; Xiang, Xinling; Lu, Qianhui; Zhang, Lanwei; Ma, Fang; Wang, Linlin

    2016-02-01

    Surface-layer associated proteins (SLAP) that envelop Lactobacillus paracasei ssp. paracasei M5-L and Lactobacillus casei Q8-L cell surfaces are involved in the adherence of these strain to the human intestinal cell line HT-29. To further elucidate some of the properties of these proteins, we assessed the yields and expressions of SLAP under different incubation conditions. An efficient and selective extraction of SLAP was obtained when cells of Lactobacillus were treated with 5 M LiCl at 37°C in aerobic conditions. The SLAP of Lactobacillus M5-L and Q8-L in cell extracts were visualized by SDS-PAGE and identified by Western blotting with sulfo-N-hydroxysuccinimide-biotin-labeled HT-29 cells as adhesion proteins. Atomic force microscopy contact imaging revealed that Lactobacillus strains M5-L and Q8-L normally display a smooth, homogeneous surface, whereas the surfaces of M5-L and Q8-L treated with 5 M LiCl were rough and more heterogeneous. Analysis of adhesion forces revealed that the initial adhesion forces of 1.41 and 1.28 nN obtained for normal Lactobacillus M5-L and Q8-L strains, respectively, decreased to 0.70 and 0.48 nN, respectively, following 5 M LiCl treatment. Finally, the dominant 45-kDa protein bands of Lactobacillus Q8-L and Lactobacillus M5-L were identified as elongation factor Tu and surface antigen, respectively, by liquid chromatography-tandem mass spectrometry.

  8. Association of Immune and Metabolic Receptors C5aR and C5L2 with Adiposity in Women

    Directory of Open Access Journals (Sweden)

    Pegah Poursharifi

    2014-01-01

    Full Text Available Adipose tissue receptors C5aR and C5L2 and their heterodimerization/functionality and interaction with ligands C5a and acylation stimulating protein (ASP have been evaluated in cell and rodent studies. Their contribution to obesity factors in humans remains unclear. We hypothesized that C5a receptors, classically required for host defense, are also associated with adiposity. Anthropometry and fasting blood parameters were measured in 136 women divided by body mass index (BMI: normal/overweight (≤30 kg/m2; n = 34, obese I (≤45 kg/m2; n = 33, obese II (≤51 kg/m2; n = 33, and obese III (≤80 kg/m2; n = 36. Subcutaneous and omental adipose tissue C5aR and C5L2 expression were analysed. C5L2 expression was comparable between subcutaneous and omental across all BMI groups. Plasma ASP and ASP/omental C5L2 expression increased with BMI (P < 0.001 and P < 0.01, resp.. While plasma C5a was unchanged, C5aR expression decreased with increasing BMI in subcutaneous and omental tissues (P < 0.01 and P < 0.05, resp., with subcutaneous omental depots. Omental C5L2/C5aR ratio increased with BMI (P < 0.01 with correlations between C5L2/C5aR and waist circumference, HDL-C, and adiponectin. Tissue and BMI differences in receptors and ligands, particularly in omental, suggest relationship to metabolic disturbances and highlight adipose-immune interactions.

  9. Effect of Plastic Deformation and Microstructure on Hydrogen Diffusion in Steel

    OpenAIRE

    Hope, Malin Sofie Berglund

    2015-01-01

    This work has been part of the ROP (Repair Contingency of Pipelines) project executed by SINTEF, where Vigdis Olden is project lead. The main content of this report is the execution of hydrogen permeation tests on Fe3wt.%Si and API X70 high strength steel. The permeation tests were performed according to the ASTM Standard Practice for Evaluation of Hydrogen Uptake, Permeation, and Transport in Metals by an Electrochemical Technique [1], and the apparatus used for testing was designed and p...

  10. Estudio del daño por hidrógeno en uniones soldadas de un acero API 5L X52

    Directory of Open Access Journals (Sweden)

    Réquiz, R.

    2008-04-01

    Full Text Available The main objective of the present investigation was to study the susceptibility to hydrogen damage on a type API 5L X52 steel welded by electrical resistance. Several techniques, such as hydrogen permeation and cathodic charging were used. The metallic material was characterized using SEM and TEM. The base metal microstructure was very similar to that one corresponding to the welded area. This microstructure was mainly comprised by ferrite and perlite, differing only in the grain size. Therefore, the susceptibility to hydrogen damage was similar in both cases. It is worth mentioning that the welded area has very small dimensions. Indeed, the fusion zone is only 5 mm wide while the heat affected zone is 1 mm wide. The hydrogen damage observed was mainly in the form of blisters, which were associated to the presence of aluminum rich inclusions. Also, it was noticed partial inclusion dissolution and some matrix attack adjacent to the inclusions.

    En la presente investigación se estudió la susceptibilidad al daño por hidrógeno en un acero API 5L X52 soldado por resistencia eléctrica. Para ello, se emplearon técnicas de permeación y de carga catódica de hidrógeno. El material fue caracterizado mediante microscopía electrónica de barrido y de transmisión. La susceptibilidad al daño por hidrógeno fue similar tanto en el metal base como en el cordón de soldadura. Este comportamiento se vincula a la microestructura homogénea constituida por perlita y ferrita, que presentan ambos, aun cuando existen diferencias en el tamaño de grano. El cordón de soldadura tenía dimensiones muy pequeñas, donde la zona de fusión y la afectada por el calor poseen espesores de 5 mm y 1 mm, respectivamente. El daño inducido por hidrógeno se presentó en forma de ampollas en la superficie del material, asociado, principalmente, a la presencia de inclusiones globulares y semiglobulares ricas en aluminio. Además, se manifestó una disoluci

  11. 对APISPEC5L/ISO3183超声波探伤对比标样的认识%Cognition of Ultrasonic Testing Reference Specimen in API SPEC 5L/ISO 3183

    Institute of Scientific and Technical Information of China (English)

    甘正红; 任文浩

    2011-01-01

    According to the reflection theory to ultrasonic testing reflection signal of several reference specimens specified in API SPEC 5L/ISO3183, this paper pointed out the respective reflection characteristics, and conducted analysis in conjunction with acceptance criteria. It put forward utilizing reference specimen according to different reflection regulation and equivalent weight to ultrasonic of notches and radial drilling hole (column hole), the both parties of contract should clearly stipulate acceptance reference specimen when adopting API SPEC 5L (44 edition) / ISO3183 standard; The level of sensitivity shall be tested and analyzed combining with the specific condition instead of simply determining result based on differences of artificial reflectors.%依据API SPEC 5L/ISO 3183标准规定的几种超声波探伤对比标样对超声波反射信号的反射理论,指出它们的各自反射特性,结合验收标准进行分析.提出了在使用对比标样时应根据刻槽和径向钻孔(柱孔)对超声波的反射规律不同、当量不同,建议在使用API SPEC 5L(第44版)/ISO3183标准时,合同双方应明确规定验收对比标样;灵敏度的高低不能简单地以人工反射体的差异来判定,要结合具体条件进行测试和分析.

  12. Calculation of the yield and tensile strength in the alloying non quenched-tempered steel by the electron structure parameters

    Institute of Scientific and Technical Information of China (English)

    LIU Zhilin; LIN Cheng; LIU Yan; GUO Yanchang

    2005-01-01

    Based on the phase transformations and strengthening mechanisms during roiling, the strength increments △σb under different strengthening mechanisms are calculated with the covalent electron number nA of the strongest bond in phase cells of alloys and the interface electron density difference △ρ matching the interface stress in alloys. The calculation method of the finishing rolling yield strength is proposed, and it is integrated with the proposed calculation formulas of strength of non quenched-tempered steel. Therefore,the general formulas to simultaneously calculate both the finishing rolling strength and the yield strength of the continuous casting-rolling and non quenched-tempered steel are given. Taken the pipeline steel X70 as an example, the predictions of properties and technological parameters are performed before production or online.

  13. Effect of natural aging on the microstructural regions, mechanical properties, corrosion resistance and fracture in welded joints on API5L X52 steel pipeline

    Directory of Open Access Journals (Sweden)

    Vargas-Arista, Benjamín

    2014-09-01

    Full Text Available A characterization study was done to analyze how microstructural regions affect the mechanical properties, corrosion and fractography of the Heat Affected Zone (HAZ, weld bead and base metal for pipe naturally aged for 21 years at 30 °C. Results showed that microstructures exhibited damage and consequently decrease in properties, resulting in over-aged due to service. SEM analysis showed that base metal presented coarse ferrite grain. Tensile test indicated that microstructures showed discontinuous yield. Higher tensile strength was obtained for weld bead, which exhibited a lower impact energy in comparison to that of HAZ and base metal associated with brittle fracture by trans-granular cleavage. The degradation of properties was associated with the coarsening of nano-carbides observed through TEM images analysis, which was confirmed by SEM fractography of tensile and impact fracture surfaces. The weld bead reached the largest void density and highest susceptibility to corrosion in H2S media when compared to those of the HAZ and base metal.Se realizó un estudio de caracterización para analizar cómo la microestructura afecta a las propiedades mecánicas, corrosión y fractura de la zona afectada por calor (ZAC, soldadura y metal base para tubería envejecida naturalmente durante 21 años a 30 °C. Los resultados indicaron que las microestructuras presentaron daño y consecuentemente reducción en propiedades mecánicas, como consecuencia del envejecimiento por servicio. El estudio mediante MEB mostró que el metal base presenta grano ferrítico grueso. La prueba de tensión indicó que las microestructuras mostraron fluencia discontinua. La mayor resistencia a la tracción se presentó en la soldadura, la cual alcanzó menor energía de impacto en comparación con la ZAC y metal base asociado con fractura frágil por clivaje transgranular. La degradación de las propriedades está en relación con el engrosamiento de nanocarburos observados a través del análisis de imágenes por MET, lo que se confirmó mediante fractografía por MEB de superfícies de fractura bajo tensión e impacto. La soldadura alcanzó la mayor densidad de microhuecos y la mayor susceptibilidad a la corrosión en un medio conteniendo H2S que cuando se compara con la ZAC y metal base.

  14. Effect of natural aging on the microstructural regions, mechanical properties, corrosion resistance and fracture in welded joints on API5L X52 steel pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Arista, B.; Albiter, A.; Garcia-Vazquez, F.; Mendoza-Camargo, O.; Hallen, J. M.

    2014-07-01

    A characterization study was done to analyze how microstructural regions affect the mechanical properties, corrosion and fractography of the Heat Affected Zone (HAZ), weld bead and base metal for pipe naturally aged for 21 years at 30 degree centigrade. Results showed that microstructures exhibited damage and consequently decrease in properties, resulting in over-aged due to service. SEM analysis showed that base metal presented coarse ferrite grain. Tensile test indicated that microstructures showed discontinuous yield. Higher tensile strength was obtained for weld bead, which exhibited a lower impact energy in comparison to that of HAZ and base metal associated with brittle fracture by trans-granular cleavage. The degradation of properties was associated with the coarsening of nano-carbides observed through TEM images analysis, which was confirmed by SEM fractography of tensile and impact fracture surfaces. The weld bead reached the largest void density and highest susceptibility to corrosion in H{sub 2}S media when compared to those of the HAZ and base metal. (Author)

  15. A Time Trade-off-derived Value Set of the EQ-5D-5L for Canada

    Science.gov (United States)

    Pullenayegum, Eleanor; Gaebel, Kathy; Bansback, Nick; Bryan, Stirling; Ohinmaa, Arto; Poissant, Lise; Johnson, Jeffrey A.

    2016-01-01

    Background: The 5-level version of the EQ-5D (EQ-5D-5L) was recently developed. A number of preference-based scoring systems are being developed for several countries around the world. Objective: To develop a value set for the EQ-5D-5L based on societal preferences in Canada. Methods: We used age, sex, and education quota sampling from the general population from 4 cities across Canada. Composite time trade-off (cTTO) and traditional time trade-off (tTTO) were used as the main elicitation technique. A total of 86 EQ-5D-5L health states grouped into 10 blocks were valued using cTTO, whereas a subset of 18 severe states was also valued using tTTO. Participants meeting predefined inconsistency criteria were excluded from the analyses. For the value set development, we used tTTO and positive cTTO values, while censoring negative and zero cTTO values at zero. Models with the main effects presented using linear terms combined with various additional terms were estimated. The preferred model was selected based primarily on logically ordered coefficients, and secondly model fit. Results: Of the 1209 participants who completed the interview, 136 met criteria that excluded them from the primary analyses. The demographics and socioeconomic status of the remaining 1073 participants were similar to the Canadian general population. The preferred model has 5 linear terms for the main effects, a term for level 4 or 5 for each dimension, and a term for the squared total number of level 4 or 5 beyond the first. For this preferred model, the health utilities ranged from −0.148 for the worst (55555) to 0.949 for the best (11111) EQ-5D-5L states. Conclusions: This is the first TTO-based value set of the EQ-5D-5L for Canada. It can be used to support the health utility estimation in economic evaluations for reimbursement decision making in Canada. PMID:26492214

  16. Measurement properties of the EQ-5D-5L compared to the EQ-5D-3L across eight patient groups

    DEFF Research Database (Denmark)

    Janssen, M F; Pickard, A Simon; Golicki, Dominik;

    2012-01-01

    PURPOSE: The aim of this study was to assess the measurement properties of the 5-level classification system of the EQ-5D (5L), in comparison with the 3-level EQ-5D (3L). METHODS: Participants (n = 3,919) from six countries, including eight patient groups with chronic conditions (cardiovascular......), redistribution properties, ceiling, discriminatory power, convergent validity, and known-groups validity. RESULTS: Missing values were on average 0.8 % for 5L and 1.3 % for 3L. In total, 2.9 % of responses were inconsistent between 5L and 3L. Redistribution from 3L to 5L using EQ dimension-specific rating scales...... as reference was validated for all 35 3L-5L-level combinations. For 5L, 683 unique health states were observed versus 124 for 3L. The ceiling was reduced from 20.2 % (3L) to 16.0 % (5L). Absolute discriminatory power (Shannon index) improved considerably with 5L (mean 1.87 for 5L versus 1.24 for 3L...

  17. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  18. EQ-5D-5L in the General German Population: Comparison and Evaluation of Three Yearly Cross-Section Surveys.

    Science.gov (United States)

    Huber, Manuel B; Reitmeir, Peter; Vogelmann, Martin; Leidl, Reiner

    2016-03-21

    Health-related quality of life (HRQoL) is a key measure for evaluating health status in populations. Using the recent EQ-5D-5L for measurement, this study analyzed quality of life results and their stability over consecutive population surveys. Three cross-section surveys for representative samples of the general German population from 2012, 2013, and 2014 were evaluated using the EQ-5D-5L descriptive system and valuation by the Visual Analog Scale (VAS). Aggregated sample size reached 6074. The dimension with the highest prevalence of problems was pain/discomfort (31.7%). Compared with 2012 (59.3%), the percentage of participants in the best health state increased slightly in 2013 (63.4%) and 2014 (62%). Over the 3-year period, diabetes and heart disease had the strongest negative influence on mean VAS result. The number of reported chronic diseases cumulatively reduced mean VAS. Extreme problems in one or more dimensions were stated by only 0.1%-0.2% of patients. Of the potential 247 health states with a problem score ≥ 20, only six were observed in the aggregated sample. HRQoL results were fairly stable over the 3 years, but the share of the population with no problems was not. Results from the aggregated sample may serve as updated reference values for the general German population.

  19. EQ-5D-5L in the General German Population: Comparison and Evaluation of Three Yearly Cross-Section Surveys

    Directory of Open Access Journals (Sweden)

    Manuel B. Huber

    2016-03-01

    Full Text Available Health-related quality of life (HRQoL is a key measure for evaluating health status in populations. Using the recent EQ-5D-5L for measurement, this study analyzed quality of life results and their stability over consecutive population surveys. Three cross-section surveys for representative samples of the general German population from 2012, 2013, and 2014 were evaluated using the EQ-5D-5L descriptive system and valuation by the Visual Analog Scale (VAS. Aggregated sample size reached 6074. The dimension with the highest prevalence of problems was pain/discomfort (31.7%. Compared with 2012 (59.3%, the percentage of participants in the best health state increased slightly in 2013 (63.4% and 2014 (62%. Over the 3-year period, diabetes and heart disease had the strongest negative influence on mean VAS result. The number of reported chronic diseases cumulatively reduced mean VAS. Extreme problems in one or more dimensions were stated by only 0.1%–0.2% of patients. Of the potential 247 health states with a problem score ≥20, only six were observed in the aggregated sample. HRQoL results were fairly stable over the 3 years, but the share of the population with no problems was not. Results from the aggregated sample may serve as updated reference values for the general German population.

  20. Reinforcing the Steel Sector

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    By pushing forward mergers between steel-makers, China gears up to consolidate the large but fragmented industryIn a government effort to consolidate the crowded steel industry and position it for fierce global competition, the state-

  1. LIVE L4 and LIVE L5L experiments on melt pool and crust behaviour in the RPV lower head

    International Nuclear Information System (INIS)

    LIVE-L4 and LIVE-L5L experiments investigated thermal hydraulic behavior of corium pool in the RPV lower head with a 3D test vessel LIVE. The simulant material is 80%-20% KNO3- NaNO3. Transient and steady-state parameters such as melt temperature, heat flux distribution through the vessel wall as well as crust formation characteristics were obtained. The two tests demonstrated that transient events like melt relocation and change of decay power facilitate crust deformation and change of crust thickness. The dimensionless melt temperature and heat flux through wall during the steady state can be well described independent of power density. However the dimensionless melt temperature and heat flux are dependent on the pool height. A low pool has stronger focusing effect at the upper surface than in a high pool. (author)

  2. The steel scrap age.

    Science.gov (United States)

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-01

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  3. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    It gives an outline of metallographic properties of welding zone of stainless steels, generation and mechanisms of welding crack and decreasing of corrosion resistance of welding zone. It consists of seven chapters such as introduction, some kinds of stainless steels and properties, metallographic properties of welding zone, weld crack, toughness of welding zone, corrosion resistance and summary. The solidification modes of stainless steels, each solidification mode on the cross section of Fe-Cr-Ni alloy phase diagram, each solidification mode of weld stainless steels metal by electron beam welding, segregation state of alloy elements at each solidification mode, Schaeffler diagram, Delong diagram, effects of (P + S) mass content in % and Cr/Ni equivalent on solidification cracking of weld stainless steels metal, solidification crack susceptibility of weld high purity stainless steels metal, effects of trace impurity elements on solidification crack susceptibility of weld high purity stainless steels metal, ductile fracture susceptibility of weld austenitic stainless steels metal, effects of H2 and ferrite content on generation of crack of weld 25Cr-5N duplex stainless steels, effects of O and N content on toughness of weld SUS 447J1 metals, effect of ferrite content on aging toughness of weld austenitic stainless steel metal, corrosion morphology of welding zone of stainless steels, generation mechanism of knife line attack phenomenon, and corrosion potential of some kinds of metals in seawater at room temperature are illustrated. (S.Y.)

  4. AN APPROACH TO ESTIMATE ROOM TEMPERATURE CREEP OF STRUCTURAL STEELS%一种估算结构钢室温蠕变的方法

    Institute of Scientific and Technical Information of China (English)

    聂德福; 赵杰; 张俊善

    2011-01-01

    Room temperature creep (RTC) behaviors of the as-rolled (AR) and normalized (Nor) X70 pipeline steel as well as the AISI304 stainless steel were investigated. At different stress levels, their RTCs mainly showed the feature of logarithmic creep with continuously falling rate. By comparing RTC with tensile tests, it was found that the loading process of RTC test was the same as the tensile test, and the strain rate at the start of RTC was equal to that at the end of loading process.Based on these results and by combining the constitutive equations of RTC with the Ramberg-Osgood equation, which is generally used to describe the stress-strain relationship in tensile tests, an approach to estimate RTC strain was presented as a function of the applied stress. On applying it to the X70 pipeline steel and AISI304 stainless steel, it was indicated that the estimated results of RTC were well consistent with the experimental data and that all the errors were within a factor of 2.%研究了轧制态、正火态X70管线钢和AISI304不锈钢的室温蠕变行为,发现在数种应力水平下此2种钢主要呈现为速率递减的对数蠕变特征.室温蠕变和拉伸实验的关系表明,室温蠕变实验中的加载过程与拉伸实验相同,且室温蠕变开始时的应变速率与加载过程结束时的相等.在此基础上,结合室温蠕变本构方程和描述拉伸实验中应力-应变关系的Ramberg-Osgood公式,提出了基于外加应力估算结构钢室温蠕变的方法.该方法得到的X70管线钢和AISI304不锈钢室温蠕变量的估算结果与实验值符合得较好,误差均在2倍因子之内.

  5. API RP 5 L3-2014输送钢管落锤撕裂试验推荐做法简介%Introduction of Drop-Weight Tear Tests on Line Pipe Recommended Practice API RP 5 L3-2014

    Institute of Scientific and Technical Information of China (English)

    孙宏

    2016-01-01

    介绍了新版的落锤撕裂试验(DWTT)的试验标准API RP 5L3-2014《输送钢管落锤撕裂试验推荐做法》,并与以前的版本API RP 5L3-1996进行了比较。对比发现新版的API RP 5L3-2014《输送钢管落锤撕裂试验推荐做法》仍然延续了API RP 5L3-1996的主要技术内容,并与国内的常用的SY/T 6476-2013和GB/T8363-2007仍然有一定差异。%The latest edition of Drop-Weight Tear Tests on Line Pipe Recommended Practice API RP 5L3-2014 was introduced compared with the last edition API RP 5L3-1996. It is found that the latest edition of API RP 5L3 still continues containing more technical content in the API RP 5L3-1996, but it is apparently different with SY/T 6476-2013 and GB/T 8363-2007, which are mainly used domestically.

  6. Modern Steel Framed Schools.

    Science.gov (United States)

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  7. CO2 corrosion resistance of carbon steel in relation with microstructure changes

    OpenAIRE

    Ochoa, Nathalie; Vega, Carlos; Pébère, Nadine; Lacaze, Jacques; Joaquín L. Brito

    2015-01-01

    International audience The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO2 was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to ...

  8. Clean Production of Steel and Refractories in China's Steel Industry

    Institute of Scientific and Technical Information of China (English)

    SU Tiansen

    2002-01-01

    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry, environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China' s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China' s steel industry.

  9. Nuclear transmutation in steels

    Science.gov (United States)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  10. Fatigue of stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Solin, J. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2010-05-15

    The 2009b update of ASME III introduces a new set of fatigue design curves. The new curve for austenitic stainless steels is exactly matching with the one endorsed in 2007 by the US NRC for new designs only. This has a notable effect in usage factor calculation at strain amplitudes below 0.5 %. However, experimental results clearly demonstrate that a new air curve would not be needed for the studied stainless steel grades. Our current results suggest arguments for use of stabilized stainless steels in NPP piping components, where high cycle fatigue (epsilon{sub a}<=0.5%) is a concern. (orig.)

  11. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  12. Life after Steel

    Science.gov (United States)

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  13. Evaluación de la susceptibilidad a la corrosión por picado del acero API 5L x42 expuesto a un ambiente con cloruros y CO2 mediante la técnica de ruido electroquímico

    Directory of Open Access Journals (Sweden)

    Rodríguez-Vanegas, N.

    2011-10-01

    Full Text Available The concentration of chloride ions and the partial pressure of CO2 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 CO2. The concentration of chloride ions was varied between, 10000 and 18000 ppm, and the CO2 partial pressure between 10 psi and 18 psi. Experimental results pointed out that the formation of protective layer, consisting mainly of FeCO 3, depends on the partial pressure of CO2 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 echnique.La concentración de iones cloruro y la presión parcial de CO2, tienen un papel importante en el proceso de degradación de los aceros de bajo carbono empleados en la construcción de líneas de transporte en industrias petroleras. Con el fin de evaluar la susceptibilidad del acero al carbono API 5L X42 a la corrosión por picado, se realizaron medidas de ruido electroquímico y resistencia a la polarización lineal en soluciones acuosas de iones cloruro con concentraciones entre 10.000 y 18.000 ppm, variando la presión parcial de CO2 entre 10 psi y 18 psi. Los resultados indican que la formación de una capa protectora, constituida principalmente por FeCO3, depende de la presión parcial de CO2 del sistema. No obstante, la estabilidad de dicha capa es afectada significativamente por el aumento de la concentración de iones cloruro, que producen fenómenos de corrosión localizada en algunas áreas de la superficie del acero API 5L X42, los cuales fueron detectados por la técnica de

  14. Articles comprising ferritic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  15. Profiles in garbage: Steel cans

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C. [Environmental Industry Associations, Washington, DC (United States)

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  16. Structural and electrical conductivity studies on the solid electrolyte system {sub x}Li2O-(100-x) [0.5B{sub 2}O{sub 3}-0.5 P{sub 2}O{sub 5}] where 20<x<70

    Energy Technology Data Exchange (ETDEWEB)

    Padmasree, K. P.; Diaz-Guillen, M. R.; Diaz-Guillen, J. A.; Mendoza, E. M.; Fuentes, A. F. [Cinvestav, unidad Saltillo, Ramos Arizpe, Coahuila (Mexico)]. E-mail: padma512@yahoo.com

    2009-09-15

    Lithium ion conducting glasses have been extensively investigated due to their potential application as solid state amorphous electrolytes in lithium rechargeable batteries. The use of glassy electrolytes in all solid state devices may provide numerous advantages like increased safety, facility of fabrication and miniaturization and having a higher conductivity than those of the crystalline counterparts. In this work, we prepared and studied the Lithium ion conducting glassy solid electrolytes of the composition {sub x}Li{sub 2}O-(1-x)[0.5B{sub 2}O{sub 3} -0.5P{sub 2}O{sub 5}] where 20<x<70, by melt quenching technique. The obtained solid material is characterized through X-ray diffraction (XRD), Differential thermal analysis (DTA), and Fourier transform infra-red spectrometry (FTIR) and impedance spectroscopy techniques. The conductivity obtained is of the order of 10-7S/cm at room temperature and IR spectra reveal that the glass matrix undergoes structural modification with the addition of the glass modifier Li{sub 2}O. [Spanish] Los vidrios conductores de ion litio se han investigado ampliamente por su aplicacion potencial como electrolitos amorfos de estado solido en baterias recargables de litio. El uso de electrolitos vitreos en todos los dispositivos de estado solido puede proporcionar numerosas ventajas como mayor seguridad, facilidad de fabricacion y miniaturizacion, asi como tener una conductividad mas alta que la de sus contrapartes cristalinas. En este trabajo, se prepararon y estudiaron los electrolitos solidos vitreos conductores de ion litio de la composicion {sub x}Li2O-(1-x)[0.5B{sub 2}O{sub 3} -0.5P{sub 2}O{sub 5}] donde 20<x<70, por medio de la tecnica de templado. El material solido obtenido se caracteriza mediante difraccion de rayos X (DRX), analisis termico diferencial (ATD) y espectrometria infrarroja de la transformada de Fourier (EITF) y tecnicas de espectroscopia por impedancia. La conductividad obtenida es del orden de 10-7S/cm a

  17. MECHANICAL PROPERTIES OF LONGITUDINAL SUBMERGED ARC WELDED STEEL PIPES USED FOR GAS PIPELINE OF OFFSHORE OIL

    Institute of Scientific and Technical Information of China (English)

    Z.Z. Yang; W. Tian; Q.R. Ma; Y.L. Li; J.K. Li; J.Z. Gao; H.B. Zhang; Y.H. Yang

    2008-01-01

    Since the development of offshore oil and gas, increased submarine oil and gas pipelines were installed. All the early steel pipes of submarine pipelines depended on importing because of the strict requirements of comprehensive properties, such as,anti-corrosion, resistance to pressure and so on. To research and develop domestic steel pipes used for the submarine pipeline, the Longitudinal-seam Submerged Arc Welded (LSAW) pipes were made of steel plates cut from leveled hot rolled coils by both the JCOE and UOE (the forming process in which the plate like the letter "J", "C", "O" or "U" shape, then expansion) forming processes. Furthermore, the mechanical properties of the pipe base metal and weld metal were tested, and the results were in accordance with the corresponding pipe specification API SPEC 5L or DNV-OS-F101, which showed that domestic LSAW pipes could be used for submarine oil and gas pipelines.

  18. Clean steels for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.

    1995-03-01

    Fusion energy production has an inherent advantage over fission: a fuel supply with reduced long term radioactivity. One of the leading candidate materials for structural applications in a fusion reactor is a tungsten stabilized 9% chromium Martensitic steel. This alloy class is being considered because it offers the opportunity to maintain that advantage in the reactor structure as well as provide good high temperature strength and radiation induced swelling and embrittlement resistance. However, calculations indicate that to obtain acceptable radioactivity levels within 500 years after service, clean steel will be required because the niobium impurity levels must be kept below about 2 appm and nickel, molybdenum, nitrogen, copper, and aluminum must be intentionally restricted. International efforts are addressing the problems of clean steel production. Recently, a 5,000 kg heat was vacuum induction melted in Japan using high purity commercial raw materials giving niobium levels less than 0.7 appm. This paper reviews the need for reduced long term radioactivity, defines the advantageous properties of the tungsten stabilized Martensitic steel class, and describes the international efforts to produce acceptable clean steels.

  19. EVALUATION OF THE INHIBITORY EFFECTIVENESS OF THREE FERROCENE DERIVATIVES FOR CORROSION OF STEEL XC70 BY SPECTROSCOPY OF ELECTROCHEMICAL IMPEDANCE

    Directory of Open Access Journals (Sweden)

    O. Rahim

    2015-07-01

    Full Text Available In this work, we studied the efficacy of corrosion inhibition of carbon steel X70 in HCl 1M solution using ferrocenyl compounds prepared in VPRS laboratory, these compounds are: N-(férrocenyl méthyl-2-nitro aniline(Fc12, N-(férrocenyl méthyl-3-nitro aniline(Fc13 and N-(férrocenyl méthyl-4-nitro aniline(Fc14.The inhibitory potency of these compounds was determined by the electrochemical impedance spectroscopy (EIS. The overall results show that these compounds have varying percentages of inhibition. The adsorption of these compounds on the surface of the metal is a chemical adsorption.In HCl 1M, the compound Fc12 had the best ability of inhibition  at a concentration of 70ppm (R = 91.24%.

  20. Thermochemical surface engineering of steels

    OpenAIRE

    2015-01-01

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels

  1. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  2. Continuous steel production and apparatus

    Science.gov (United States)

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  3. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu;

    2014-01-01

    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  4. A-3 steel work completed

    Science.gov (United States)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  5. 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.

  6. Thermomechanical treatment of steel

    International Nuclear Information System (INIS)

    Thermomechanical treatment is defined as a process in which a forming operation is carried out in the course of a treatment in order to improve the mechanical properties of a material. Several thermomechanical processes for the treatment of steel are described. (WBU)

  7. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  8. Influencia del precalentamiento en las propiedades de uniones soldadas de acero API 5L-X80 soldadas con alambre tubular autoprotegido

    OpenAIRE

    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 (IG), 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 te...

  9. History of ultrahigh carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

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

  10. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

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

  11. Characterisation of weldment hardness, impact energy and microstructure in API X65 steel

    International Nuclear Information System (INIS)

    The variation of microstructure and mechanical properties in various sub-zones of double submerged arc welded line pipe steel of grade API X65 was investigated. Instrumented Charpy V-notch tests and Vickers hardness experiments were conducted on the fusion zone, base metal and heat affected zone of the weld joint in 14.3 mm thick, 1219 mm outside diameter spiral pipeline. The lowest impact energy and the highest hardness level (160J and 218 HV, respectively) were recorded in the fusion zone. The low energy and high hardness characteristics of the seam weld can be attributed to its cast microstructure and the presence of grain boundary phases (such as proeutectoid ferrite), confirmed by standard metallographic observation. Despite this, service requirements set by the API 5L industry code (minimum impact energy of 73J, maximum hard spots of 350 HV) were fulfilled by the tested steel. Highlights: ► Experimental study of API X65 steel microstructure. ► Analysis of the relationship between X65 steel microstructure and hardness. ► Analysis of the relationship between X65 steel microstructure and impact energy. ► Presentation of detailed technical information on DSA welding in spiral pipes.

  12. Steels and welding nuclear

    International Nuclear Information System (INIS)

    This ENEA Data-Base regards mechanical properties, chemical composition and heat treatments of nuclear pressure vessel materials: type A533-B, A302-B, A508 steel plates and forgings, submerged arc welds and HAZ before and after nuclear irradiation. Irradiation experiments were generally performed in high flux material test reactors. Data were collected from international available literature about water nuclear reactors pressure vessel materials embrittlement

  13. Contaminated Mexican steel incident

    International Nuclear Information System (INIS)

    This report documents the circumstances contributing to the inadvertent melting of cobalt 60 (Co-60) contaminated scrap metal in two Mexican steel foundries and the subsequent distribution of contaminated steel products into the United States. The report addresses mainly those actions taken by US Federal and state agencies to protect the US population from radiation risks associated with the incident. Mexico had much more serious radiation exposure and contamination problems to manage. The United States Government maintained a standing offer to provide technical and medical assistance to the Mexican Government. The report covers the tracing of the source to its origin, response actions to recover radioactive steel in the United States, and return of the contaminated materials to Mexico. The incident resulted in significant radiation exposures within Mexico, but no known significant exposure within the United States. Response to the incident required the combined efforts of the Nuclear Regulatory Commission (NRC), Department of Energy, Department of Transportation, Department of State, and US Customs Service (Department of Treasury) personnel at the Federal level and representatives of all 50 State Radiation Control Programs and, in some instances, local and county government personnel. The response also required a diplomatic interface with the Mexican Government and cooperation of numerous commercial establishments and members of the general public. The report describes the factual information associated with the event and may serve as information for subsequent recommendations and actions by the NRC. 8 figures

  14. Stainless Steel Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Karnesky, Richard A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  15. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  16. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  17. Strip casting of stainless steels

    OpenAIRE

    Raabe, D.

    1997-01-01

    FLAT PRODUCTS OF STAINLESS STEELS ARE CONVENTIONALLY MANUFACTURED BY CONTINUOUS CASTING, HOT ROLLING, HOT BAND ANNEALING, PICKLING, COLD ROLLING AND RECRYSTALLISATION. IN THE LAST YEARS STRIP CASTING HAS INCREASINGLY ATTRACTED ATTENTION. IT OFFERS THREE IMPROVEMENTS IN COMPARISON TO THE CONVENTIONAL METHOD.1.) IT ALLOWS TO CAST STEEL SHEETS WITH THE SAME THICKNESS AND WIDTH AS THOSE PRODUCED BY HOT ROLLING. THIS MEANS THAT THE HOT ROLLING PROCESSIS BYPASSED. 2.) THE STRIP CAST STEEL REVEALS A...

  18. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  19. Synthesis of thermit noncorrodible steels

    OpenAIRE

    Жигуц, Юрій Юрійович

    2013-01-01

    The present paper the basic solutions to the problem of obtaining cavitation-resistant steels examined the use of thermite steels, the benefits of combining thermite steels with metallotermic methods of getting is showed. The advantages of metallotermic synthesis methods include: autonomy of processes, independence of energy sources, simplicity of equipment, high-performance process and easy transition from experimental research to industrial production. The need to developed the technology o...

  20. Mechanics in Steels through Microscopy

    OpenAIRE

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP steels, highlighting the importance of microstructure - mechanical properties - applications relationships. In Chapter 2 the material properties and material processing are described into more detai...

  1. Tough Year Ahead for Steel

    Institute of Scientific and Technical Information of China (English)

    REN WEI

    2006-01-01

    @@ The steel industry, a top beneficiary of the country's sizzling economic growth, is this year likely to see only a meager profit or even report losses, according to a report by the National Development and Reform Commission. Mounting demand for steel in real estate construction and auto making during the past years resulted in an investment craze into the sector, and has caused a glut on the market. Average steel prices fell by a third last year, though domestic steel makers still managed to post a profit of 127.4 billion yuan (US$15.9 billion) on aggregate.

  2. Effect of Stress on Corrosion at Crack Tip on Pipeline Steel in a Near-Neutral pH Solution

    Science.gov (United States)

    Yang, Yao; Cheng, Y. Frank

    2016-10-01

    In this work, the local corrosion at crack tip on an API 5L X46 pipeline steel specimens was investigated under various applied loads in a near-neutral pH solution. Electrochemical measurements, including potentiodynamic polarization and electrochemical impedance spectroscopy, combined with micro-electrochemical technique and surface characterization, were conducted to investigate the effect of stress on local anodic solution of the steel at the crack tip. The stress corrosion cracking of the steel was dominated by an anodic dissolution mechanism, while the effect of hydrogen was negligible. The applied load (stress) increased the corrosion rate at the crack tip, contributing to crack propagation. The deposit of corrosion products at the crack tip could protect somewhat from further corrosion. At sufficiently large applied loads such as 740 N in the work, it was possible to generate separated cathode and anode, further accelerating the crack growth.

  3. Accelerated carbonation of steel slags using CO2 diluted sources: CO2 uptakes and energy requirements

    OpenAIRE

    Renato eBaciocchi; Giulia eCosta; Alessandra ePolettini; Raffaella ePomi; Alessio eStramazzo; Daniela eZingaretti

    2016-01-01

    This work presents the results of carbonation experiments performed on Basic Oxygen Furnace (BOF) steel slag samples employing gas mixtures containing 40 and 10% CO2 vol. simulating the gaseous effluents of gasification and combustion processes respectively, as well as 100% CO2 for comparison purposes. Two routes were tested, the slurry phase (L/S=5 l/kg, T=100 °C and Ptot=10 bar) and the thin film (L/S =0.3-0.4 l/kg, T=50 °C and Ptot=7-10 bar) routes. For each one, the CO2 uptake achieved as...

  4. On the estimation of the magnetic easy axis in pipeline steels using magnetic Barkhausen noise

    Science.gov (United States)

    Martínez-Ortiz, P.; Pérez-Benitez, J. A.; Espina-Hernández, J. H.; Caleyo, F.; Hallen, J. M.

    2015-01-01

    A method for determination of the magnetic easy axis of the Roll Magnetic Anisotropy in API-5L steels is proposed. The method is based on the fact that the angular dependence of the energy corresponding to the main peak of the Magnetic Barkhausen signal presents uniaxial anisotropy with its easy axis parallel to the rolling direction, independently of the angular dependence of the magnetocrystalline energy in the materials. The proposal is also justified based on the analysis of the influence of microstructural changes, produced by hot-rolling on the domain wall dynamics.

  5. Hydrogen Sulfide Corrosion of Weld Regions in API X52 Steel

    Directory of Open Access Journals (Sweden)

    García-Cerecero G.

    2012-10-01

    Full Text Available 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 (H2S-containing brine and in H2S-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 H2S corrosion. Base metal exhibited the highest corrosion rate (CR and the most cathodic corrosion potential.

  6. Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

    DEFF Research Database (Denmark)

    Berglund, J.; Brown, C.A.; Rosén, B.-G.;

    2010-01-01

    This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

  7. Isolation and characterization of P1 minireplicons, lambda-P1:5R and lambda-P1:5L.

    OpenAIRE

    Sternberg, N; Austin, S

    1983-01-01

    We have isolated two new classes of P1 miniplasmids, called lambda-P1:5R and lambda-P1:5L, by the in vivo extension of a cloned P1 fragment, EcoRI-5, which by itself is not capable of plasmid replication. The lambda-P1:5R plasmids contain EcoRI-5 plus a variable portion of the adjacent P1 EcoRI fragment 8. They have a copy number like that of P1 (about 1 per host chromosome), are faithfully segregated at cell division, and are subject to incompatibility exerted by either a single copy of P1 o...

  8. Overview of pressure-drawdown production-test results for the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, S.H.; Carle, D.; Weatherill, B. [APA Petroleum Engineering Ltd., Calgary, AB (Canada); Dallimore, S.R. [Geological Survey of Canada, Pacific Geoscience Centre, Sidney, BC (Canada); Collett, T.S. [United States Geological Survey, Denver, CO (United States); Satoh, T. [Japan Petroleum Exploration Co. Ltd., Tokyo (Japan); Inoue, T. [Japan National Oil Corp., Chiba (Japan)

    2005-07-01

    Schlumberger's Modular Dynamic Tester (MDT) cased hole wireline tool was used during a pressure drawdown production test at the Mallik 5L-38 well to successfully test separate hydrate intervals as well as free gas and water zones. This paper provided an overview of the pressure-drawdown testing operations and results. Preliminary analysis of the gas hydrate porous-media response was also presented. Two important phenomena were observed during the hydrate tests: (1) free gas was produced on a steady state basis following the initial clean-up flow of water, and (2) the pressure response upon shut-in displayed porous media effects and indicated both flow contribution and pressure effects beyond the surface area of the hydrate open to the wellbore. Since analytical pressure transient analysis software cannot incorporate dynamic reservoir parameters, conventional analytical techniques were used to evaluate the test data.

  9. Mechanism of thermal ring closure of M(CO) sub 5 L (L = bidentate ligand) produced during photolysis of group 6 hexacarbonyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.B.; van Eldik, R. (Univ. of Witten/Herdecke (West Germany))

    1990-05-01

    The kinetics of the thermal ring-closure reactions of M(CO){sub 5}L, produced during the photolysis of M(CO){sub 6}/L for L = ethylenediamine (en) and 1,4-diisopropyl-1,4-diazabutadiene (dab), were studied as a function of (L), temperature, and pressure. The values of {Delta}S{double dagger} and {Delta}V{double dagger} are significantly negative, {minus}40 to {minus}170 J K{sup {minus}1} mol{sup {minus}1} and {minus}5.4 to {minus}13.7 cm{sup 3} mol{sup {minus}1}, respectively, for M = Cr (L = en) and M = Mo, W (L = en, dab) and support an associative ring-closure mechanism. The results demonstrate the crucial role played by the size of the metal center and the steric hindrance on L.

  10. Steels for nuclear power. I

    International Nuclear Information System (INIS)

    The principles are listed of nuclear reactor operation and the reactors are classified by neutron energy, fuel and moderator designs, purpose and type of moderator. The trend and the development of light-water reactor applications are described. The fundamental operating parameters of the WWER type reactors are indicated. The effect is discussed of neutron radiation on reactor structural materials. The characteristics are described of steel corrosion due to the contact of the steel with steam or sodium in the primary coolant circuit. The reasons for stress corrosion are given and the effects of radiation on corrosion are listed. The requirements and criteria are given for the choice of low-alloy steel for the manufacture of pressure vessels, volume compensators, steam generators, cooling conduits and containment. A survey is given of most frequently used steels for pressure vessels and of the mechanical and structural properties thereof. The basic requirements for the properties of steel used in the primary coolant circuit are as follows: sufficient strength in operating temperature, toughness, good weldability, resistance to corrosion and low brittleness following neutron irradiation. The materials are listed used for the components of light-water and breeder reactors. The production of corrosion-resistant steels is discussed with a view to raw materials, technology, steel-making processes, melting processes, induction furnace steel-making, and to selected special problems of the chemical composition of steels. The effects are mainly discussed of lead, bismuth and tin as well as of some other elements on hot working of high-alloy steels and on their structure. The problems of corrosion-resistant steel welding and of pressure vessel cladding are summed up. Also discussed is the question of the concept and safeguards of the safety of nuclear installation operation and a list is presented of most commonly used nondestructive materials testing methods. The current

  11. The Bo1-specific PCR marker AWW5L7 is predictive of boron tolerance status in a range of exotic durum and bread wheats.

    Science.gov (United States)

    Schnurbusch, Thorsten; Langridge, Peter; Sutton, Tim

    2008-12-01

    High soil boron (B) constitutes a major soil problem in many parts of the world, particularly in low-rainfall areas and land under irrigation. Low accumulation of B in the shoot or grain of cereal crops is correlated with the maintenance of biomass production and grain yield under high B conditions, suggesting that this trait is an important component of field tolerance. A novel screening protocol to measure B accumulation in aerated and supported hydroponics was validated using a set of known and exotic bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) accessions. Furthermore, B accumulation in two Triticum urartu Tumanian ex Gandilyan and 54 Triticum monococcum L. accessions was measured and showed considerable phenotypic variation. However, B accumulation in these lines was higher than that observed in the most tolerant durum or bread wheats. Mapping of high B tolerance in the durum population AUS14010/Yallaroi revealed a locus possibly allelic to Bo1, a major source of B toxicity tolerance previously identified in bread wheat. Here, we show that the Bo1-specific codominant PCR marker AWW5L7 is predictive of B tolerance status among exotic durum and bread wheat accessions. All tolerant durum accessions assayed carried very similar AWW5L7 marker fragments, indicating wide distribution of this allele among tolerant durum wheats. Three bread wheat accessions had tolerance that was independent of Bo1 and is probably located on chromosome 4A. These lines represent a valuable genetic resource for B toxicity tolerance breeding in wheat. PMID:19088810

  12. Speeding up the solar water disinfection process (SODIS) against Cryptosporidium parvum by using 2.5l static solar reactors fitted with compound parabolic concentrators (CPCs).

    Science.gov (United States)

    Gómez-Couso, H; Fontán-Sainz, M; Fernández-Ibáñez, P; Ares-Mazás, E

    2012-12-01

    Water samples of 0, 5, and 100 nephelometric turbidity units (NTU) spiked with Cryptosporidium parvum oocysts were exposed to natural sunlight in 2.5l static borosilicate solar reactors fitted with two different compound parabolic concentrators (CPCs), CPC1 and CPC1.89, with concentration factors of the solar radiation of 1 and 1.89, respectively. The global oocyst viability was calculated by the evaluation of the inclusion/exclusion of the fluorogenic vital dye propidium iodide and the spontaneous excystation. Thus, the initial global oocyst viability of the C. parvum isolate used was 95.3 ± 1.6%. Using the solar reactors fitted with CPC1, the global viability of oocysts after 12h of exposure was zero in the most turbid water samples (100 NTU) and almost zero in the other water samples (0.3 ± 0.0% for 0 NTU and 0.5 ± 0.2% for 5 NTU). Employing the solar reactors fitted with CPC1.89, after 10h exposure, the global oocyst viability was zero in the non-turbid water samples (0 NTU), and it was almost zero in the 5 NTU water samples after 8h of exposure (0.5 ± 0.5%). In the most turbid water samples (100 NTU), the global viability was 1.9 ± 0.6% after 10 and 12h of exposure. In conclusion, the use of these 2.5l static solar reactors fitted with CPCs significantly improved the efficacy of the SODIS technique as these systems shorten the exposure times to solar radiation, and also minimize the negative effects of turbidity. This technology therefore represents a good alternative method for improving the microbiological quality of household drinking water in developing countries.

  13. Niobium in rail steels

    International Nuclear Information System (INIS)

    The strengthening capacity of niobium in high carbon steels is governed by the carbon content, soaking conditions prior to rolling and the finish rolling temperature. Yield and tensile strengths may be increased by up to 70-100 MPa (10-15 k.s.i.) in C-Mn-Cr rails with niobium additions of about 0.03 percent. The strengthening mechanism appears to be precipitation hardening of niobium carbonitride in the pro-eutectoid ferrite and ferrite lamellae in pearlite. In addition, ductility improvements may be effected through the austenite grain refining action of niobium in hot rolling leading to a reduction in pearlite colony size

  14. Steel designers' handbook

    CERN Document Server

    Gorenc, Branko; Tinyou, Ron

    2012-01-01

    The Revised 7th Edition of Steel Designers' Handbook is an invaluable tool for all practising structural, civil and mechanical engineers as well as engineering students at university and TAFE in Australia and New Zealand. It has been prepared in response to changes in the design Standard AS 4100, the structural Design Actions Standards, AS /ANZ 1170, other processing Standards such as welding and coatings, updated research as well as feedback from users. This edition is based on Australian Standard (AS) 4100: 1998 and subsequent amendments. The worked numerical examples in the book have been e

  15. Mechanics in Steels through Microscopy

    NARCIS (Netherlands)

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP s

  16. The industrial ecology of steel

    Energy Technology Data Exchange (ETDEWEB)

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  17. Challanges in Steel Science & Technology

    OpenAIRE

    Prahl, Ulrich; Santofimia, María Jesús; Yardley, Vicky; Gautier, Elisabeth; Tasan, Cem; Hedström, Peter; San Martín, David; PETROV Roumen; Jiménez, José A.; Almagro Bello, Juan F.; Gutiérrez, Isabel; Casellas, Daniel; Kerscher, Eberhard; Sabirov, IIchat; García, Ignacio

    2014-01-01

    Ponencias de WorkShop Advanced Steels 2014. Challenges in Steel Science & Technology. Celebrado en la central del CSIC, c/Serrano, 17, del 18 y 10 de septiembre de 2014.Organizado por: CENIM-CSIC, ASCO Industries (Fr), ASM Spain Chapter (Es), CTM (Es).

  18. Steels from materials science to structural engineering

    CERN Document Server

    Sha, Wei

    2013-01-01

    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  19. Dual phase bainitic linepipe steels

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, D.; Yakubtsov, I.; Zhang, R. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering; Poruks, P. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Turi, T. [Stelco Lake Erie, Nanticoke, ON (Canada); Emadi, D.; Essadiqi, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Lab

    2005-07-01

    Over the past 50 years, the strength of commercial linepipe steel has increased at a steady rate of about 70 MPa per decade due to advances in steelmaking, plate processing and microstructural design. API X100 grade steel, which has a yield strength of 690 MPa, is currently available, and X120 steels are under development. The microstructure of linepipe steels has evolved from predominantly polygonal ferrite to fine bainite. For the X120 steels, lower bainite-, tempered lath martensite- and dual phase microstructures are being examined. This study obtained the microstructures of ultrafine bainite with dispersed particles of the carbon-rich martensite-austenite (M-A) phase. The objective was to obtain a matrix of mostly intragranularly-nucleated bainitic ferrite containing a high volume fraction of dispersed M-A particles. The mechanical properties of bainitic linepipe steels were also examined. Basic studies of phase transformations and mechanical properties in these steels established significant relationships between processing schedule and the evolution of microstructure, and between final microstructure and mechanical properties. The optimal combination of strength and toughness properties was obtained with a microstructure consisting of a matrix of intragranularly-nucleated bainite and small dispersed particles of martensite. This microstructure was described as being a dual phase acicular ferrite (AF) with M-A. The window of steel composition and processing parameters which give the dual phase AF-M-A microstructure was determined in an experimental study on 15 mm thick plate. The minimum strength and toughness properties for Grade 621 (X90) linepipe steel can be achieved by either a lean steel composition with extreme processing parameters, or by a higher alloy composition with a more industrially realistic processing schedule. This study also proposed how this approach can be extended to obtain high strength linepipe grades. 15 refs., 9 tabs., 10 figs.

  20. Nanoprecipitation in bearing steels

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, A.T.W. [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Rivera-Diaz-del-Castillo, P.E.J., E-mail: pejr2@cam.ac.uk [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

    2011-11-15

    {theta}-phase is the main hardening species in bearing steels and appears in both martensitically and bainitically hardened microstructures. This work presents a survey of the microstrucural features accompanying nanoprecipitation in bearing steels. Nanoprecipitate structures formed in 1C-1.5Cr wt.% with additions of Cr, Mn, Mo, Si and Ni are studied. The work is combined with thermodynamic calculations and neural networks to predict the expected matrix composition, and whether this will transform martensitically or bainitically. Martensite tetragonality, composition and the amount of retained austenite are related to hardness and the type of nanoprecipitate structures in martensitic grades. The {theta}-phase volume fraction, the duration of the bainite to austenite transformation and the amount of retained austenite are related to hardness and a detailed quantitative description of the precipitate nanostructures. Such description includes compositional studies using energy-dispersive spectroscopy, which shows that nanoprecipitate formation takes place under paraequilibrium. Special attention is devoted to a novel two-step bainite tempering process which shows maximum hardness; we prove that this is the most effective process for incorporating solute into the precipitates, which are finer than those resulting from one-step banitic transformation processes.

  1. Influence of the steel scrap classes on the liquid steel output molten in electric steel processes

    Directory of Open Access Journals (Sweden)

    K. Janiszewski

    2012-12-01

    Full Text Available Purpose: This is why we have analysed in the paper, using statistical analysing methods, the influence of use in the electric arc furnace charges of steel scrap of different qualities on the index of liquid steel output from a melt.Design/methodology/approach: The used research methodology consists in analytical simulation of variations in mass of liquid steel obtained from melts differing in steel scrap content in the metallic charge and statistical analyses of industrial results acquired from the corresponding process documentation (so called melt cards.Findings: Basing on the analytical and statistical analyses carried out we have determine resulting variations in the liquid steel per melt ratios depending on the content of steel scrap in the metallic charge.Research limitations/implications: The research results obtained can be utilized in each steelmaking facility, which employs the Electric Steelmaking process, in order to “design” the metallic charge compositions, having in view the quality and economic aspects.Practical implications: The research results presented in the paper can be used for steel production of high purity steels.Originality/value: The results presented in this paper are directed to the steelmakers employing the Electric Steelmaking process and constitute the authors’ original study.

  2. Improving the toughness of ultrahigh strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Koji

    2002-08-15

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  3. High-strength, low-alloy steels.

    Science.gov (United States)

    Rashid, M S

    1980-05-23

    High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections. Their high strength is derived from a combination of grain refinement; precipitation strengthening due to minor additions of vanadium, niobium, or titanium; and modifications of manufacturing processes, such as controlled rolling and controlled cooling of otherwise essentially plain carbon steel. HSLA steels are less formable than lower strength steels, but dualphase steels, which evolved from HSLA steels, have ferrite-martensite microstructures and better formability than HSLA steels of similar strength. This improved formability has substantially increased the utilization potential of high-strength steels in the manufacture of complex components. This article reviews the development of HSLA and dual-phase steels and discusses the effects of variations in microstructure and chemistry on their mechanical properties. PMID:17772810

  4. Cold-formed steel design

    CERN Document Server

    Yu, Wei-Wen

    2010-01-01

    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  5. Modelling fracture in ferritic steel

    CERN Document Server

    Smith, G

    2002-01-01

    Results from mathematical models and computer simulations of fracture in polycrystalline steels are presented for a range of temperatures. The proportions of intergranular and intragranular failure predicted are compared with experimental results for brittle fracture, ductile fracture and in the transition region. Interactive software to create two-dimensional polycrystalline models, which allow a range of physical to be varied independently, is described. The results include those for model materials chosen to match steels used by the power generation industry. The models simulate segregation and cavitation effects in steel and fracture of weldments and their associated heat-affected zones.

  6. Stainless steel denitriding with slag

    International Nuclear Information System (INIS)

    Calculation and experimental methods were used to investigate the process of titanium nitride formation when alloying chromium nickel stainless steels with titanium. At common concentrations of titanium and nitrogen, titanium nitrides were observed to be precipitated from the melt into slag in amounts of 0.1% and more. The laboratory study of the slag influence of the process of steel refining from titanium nitrides showed that the slag containing calcium, aluminium and magnesium oxides is favourable to the denitriding of steel. In addition, the possibility of direct transition of dissolved nitrogen from the metal into the slag is revealed. 7 refs., 1 fig., 2 tabs

  7. Detection of gamma-rays with a 3.5 l liquid xenon ionization chamber triggered by the primary scintillation light

    CERN Document Server

    Aprile, E; Chen Dan Li; Muhkerjee, R; Xu Fan

    2002-01-01

    A gridded ionization chamber with a drift length of 4.5 cm and a total volume of 3.5 l, was operated with high-purity liquid xenon and extensively tested with gamma-rays from sup 1 sup 3 sup 7 Cs, sup 2 sup 2 Na and sup 6 sup 0 Co radioactive sources. An electron lifetime in excess of 1 ms was inferred from two independent measurements. The electric field dependence of the collected charge and energy resolution was studied in the range 0.1-4 kV/cm, for different gamma-ray energies. With an electric field of 4 kV/cm, the spectral performance of the detector is consistent with an energy resolution of 5.9% at 1 MeV, scaling with energy as E sup - sup 0 sup . sup 5. The chamber was also used to detect the primary scintillation light produced by gamma-ray interactions in liquid xenon. The light signal was successfully used to trigger the acquisition of the charge signal with a FADC readout. A trigger efficiency of approx 85% was measured at 662 keV.

  8. Development and validation of a real time PCR for the detection of myxoma virus based on the diploid gene M000.5L/R.

    Science.gov (United States)

    Duarte, Margarida Dias; Barros, Sílvia Carla; Henriques, Ana Margarida; Fagulha, Maria Teresa; Ramos, Fernanda; Luís, Tiago; Fevereiro, Miguel

    2014-02-01

    The myxoma virus (MYXV) causes severe infections in European rabbits that may reach mortality rates up to 100% depending on the viral strain. The typical symptoms and lesions induced by the virus are usually enough to permit the correct clinical diagnosis. However, in peracute forms the infection may be accompanied by unspecific symptoms. Sudden death may also occur without evident clinical signs of myxomatosis. Likewise, a clinical diagnosis of atypical forms of myxomatosis (amyxomatous) is often complicated and delayed due to the scarceness of skin lesions. As the disease control often depends on an early and unequivocal diagnosis of MYXV, laboratorial methods play a relevant role in the confirmation of MYXV infection. This study describes the development and validation of a novel, high accurate real time polymerase chain reaction assay (rtPCR) for the detection of MYXV. Primers were designed to amplify a 125-bp within the gene M000.5L/R, which is duplicated in the termini of the genome and is unique among Leporipoxvirus. The assay was negative for SFV and other poxviruses and was able to detect 2.6 copies of MYXV DNA proving the effectiveness, specificity and sensitivity of this diagnosis tool. The rtPCR has been applied successfully in INIAV laboratory for routine diagnosis of myxomatosis since 2005. PMID:24300832

  9. Occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in Oligocene sediments from the Mallik 5L-38 Gas Hydrate Production Research Well (Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Haberer, R.M.; Mangelsdorf, K.; Wilkes, H.; Horsfield, B. [Geoforschungszentrum Potsdam, Potsdam (Germany)

    2006-07-01

    The aromatic hydrocarbon biomarker distributions of thirty Oligocene sediment samples with different lithology (lignite, clay and sand) from the JAPEX/JNOC/GSC et al. Mallik 5L-38 Gas Hydrate Production Research Well, Canada, were analyzed using gas chromatography-mass spectrometry (GC-MS). The compositions vary with lithology, indicating a change in palaeoenvironmental conditions at the time of deposition. Aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm (e.g., conifer) dominated palaeovegetation. In contrast, in the clay samples aromatic triterpenoids are generally preserved as major constituents, indicating angiosperm dominated vegetation. The sand samples contain only minor amounts of aromatic terpenoids, but show a preference for diterpenoid gymnosperm markers. To recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio, termed the angiosperm-gymnosperm aromatic ratio (AGAR), has been developed. Thus, the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the Mallik site (lignites) and the hinterland (clays) over time. Concomitantly, the changing dominance in the plant communities allows an insight into varying climatic conditions during the late Oligocene in the area.

  10. Stainless steel display evaluation

    Science.gov (United States)

    Hopper, Darrel G.; Meyer, Frederick M.; Longo, Sam J.; Trissell, Terry L.

    2007-04-01

    Active matrix organic light emitting diode (AMOLED) technology is one candidate to become a low power alternative in some applications to the currently dominant, active matrix liquid crystal display (AMLCD), technology. Furthermore, fabrication of the AMOLED on stainless steel (SS) foil rather than the traditional glass substrate, while presenting a set of severe technical challenges, opens up the potential for displays that are both lighter and less breakable. Also, transition to an SS foil substrate may enable rollable displays - large when used but small for stowage within gear already worn or carried or installed. Research has been initiated on AMOLED/SS technology and the first 320 x 240 color pixel 4-in. demonstration device has been evaluated in the AFRL Display Test and Evaluation Laboratory. Results of this evaluation are reported along with a research roadmap.

  11. Review on Cold-Formed Steel Connections

    OpenAIRE

    Yeong Huei Lee; Cher Siang Tan; Shahrin Mohammad; Mahmood Md. Tahir; Poi Ngian Shek

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connection...

  12. Some peculiarities of corrosion of wheel steel

    OpenAIRE

    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Pinchuk, Sofia; Gubenko, Svetlana

    2009-01-01

    Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosi...

  13. Effects of changes in steel industry concentration

    OpenAIRE

    Bobenič, T.; A. Bobenič Hintošová; Hliboká, L.; I. Vasková

    2015-01-01

    The paper on a basis of completed mergers and acquisitions within global steel industry presents changes in steel industry concentration and analyzes its effects on world trade with steel products and on prices of input materials as well as of output products. The analyses performed for the 1990 - 2012 period revealed that increased concentration in global steel industry did not lead to more intensive world trade with steel products; however it is connected with increase of finished products ...

  14. CHANGES IN DISTRIBUTION OF STEEL PRODUCTS

    OpenAIRE

    Beata Œlusarczyk

    2009-01-01

    Steel industry is one of the most globalized branch, globalization has had the influence on iron ore supply, steel production and distribution as well. In last years, steel products distribution process has changed significantly, because of rising competitiveness due to common world market influence and main global players actions. The paper presents changes in steel products distribution in Poland focusing on main steel producers activity in distribution as well as distributors response on n...

  15. 2169 steel waveform experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  16. Complement Receptors C5aR and C5L2 Are Associated with Metabolic Profile, Sex Hormones, and Liver Enzymes in Obese Women Pre- and Postbariatric Surgery

    Directory of Open Access Journals (Sweden)

    Reza Rezvani

    2014-01-01

    Full Text Available Objective. Obesity is associated with metabolic dysfunction with sex differences and chronic, low-grade inflammation. We proposed that hepatic expression of immune complement C3 related receptors (C3aR, C5aR, and C5L2 would be associated with pre- or postmenopausal status and metabolic profile in severely obese women. We hypothesized that C5L2/C5aR ratio, potentially influencing the ASP/C5L2 metabolic versus C5a/C5aR immune response, would predict metabolic profiles after weight loss surgery. Materials and Methods. Fasting plasma (hormone, lipid, and enzyme analysis and liver biopsies (RT-PCR gene expression were obtained from 91 women during surgery. Results. Hepatic C5L2 mRNA expression was elevated in pre- versus postmenopausal women (P<0.01 and correlated positively with circulating estradiol, estrone, ApoB, ApoA1, ApoA1/B, waist circumference, age, and LDL-C (all P<0.05. While plasma ASP was lower in pre- versus postmenopausal women (P<0.01, the hepatic C5L2/C5aR mRNA ratio was increased (P<0.001 and correlated positively with estrone (P<0.01 and estradiol (P<0.001 and negatively with circulating ApoB and liver enzymes ALT, AST, and GGT (all P<0.05. Over 12 months postoperatively, liver enzymes in low C5L2/C5aR mRNA ratio group remained higher (ALP and ALT, P<0.05, AST and GGT, P<0.001 2-way-ANOVA. Conclusion. C5L2-C5aR association with other mediators including estrogens may contribute to hepatic metabolic and inflammatory function.

  17. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    Science.gov (United States)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  18. Mechanical Behaviour and Microstructural Characterization of Carbon Steel Samples from Three Selected Steel Rolling Plants

    OpenAIRE

    P. O. Atanda; Abioye, A. A.; A. O. Iyiola

    2015-01-01

    The research investigated the mechanical behavior of samples of steel rods obtained from three selected Steel Rolling Companies in South Western part of Nigeria. This was done by carrying out some mechanical tests such as tensile, impact and hardness as well as microstructural examination.Four sets of 16 mm steel rod samples were collected from Tiger steel industries, Phoenix steel and Oxil steel Industies, all located in South West Nigeria, The chemical composition was carried out using a...

  19. Hydrogen embrittlement of structural steels.

    Energy Technology Data Exchange (ETDEWEB)

    Somerday, Brian P.

    2010-06-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  20. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Debanshu Bhattacharya

    2014-12-01

    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  1. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.;

    2004-01-01

    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. Th......This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot...

  2. Chinese steel: limits to growth

    Energy Technology Data Exchange (ETDEWEB)

    Hites, B. [World Steel Dynamics, Englewood Cliffs, NJ (US)

    2004-07-01

    Twenty one slides/overheads outline the opinion of World Steel Dynamics (WSD) on the future of China's steel industry. Until recently WSD likened this to a Greyhound bus, experiencing massive expansion and gaining momentum. Now constraints have emerged and a new analogy is being used, of a freight train - with slower growth, from 2005-2010 of 5-7% per annum. Ten reasons are identified for this slower growth.

  3. Streamlining Iron and Steel Production

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Eliminating unproductive iron and steel facilities is vital to environmental protection and sustainable development of this industry The Chinese Government is once again shutting down unproductive plants in tune with its green policy and the march toward sustainable development.This time it’s the iron and steel industry to feel the brunt of the Chinese Government’s stringent measures. The deafening buzz of factory floors have

  4. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; I. Díaz; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  5. Fatigue Strength of Weathering Steel

    OpenAIRE

    Kunz, Ludvík; Lukáš, Petr; Klusák, Jan

    2012-01-01

    Fatigue behaviour of Atmofix 52 steel (comparable to COR-TENâ steel) exposed to atmospheric corrosion for 20 years was investigated. S-N curves for load symmetrical cycling and cycling with stress ratio R = 0 were determined on specimens detracted from a failed transmission tower. The data were compared with those on material without a rust layer. The fracture surfaces and, in particular, the sites of fatigue crack initiation were analyzed. Substantial decrease of fatigue life and fatigue lim...

  6. Fatigue properties of weathering steel

    OpenAIRE

    Zavadilová, Petra

    2012-01-01

    This work deals with the influence of atmospheric corrosion on high-cycle fatigue properties of a weathering steel ATMOFIX B. New experimental data on fatigue strength of a steel exposed for 20 years to an atmospheric corrosion were compared to those characterizing the base material. Reduction of the fatigue lifetime of the exposed material compared with the base material was predicted on the basic of fractographic examination of fracture surfaces and the influence of surface notches on fatig...

  7. Fatique behaviour of electrical steel

    Directory of Open Access Journals (Sweden)

    Bode B.

    2014-06-01

    Full Text Available Electrical steel comes into focus with the development of electrically powered cars. In contrast to electrical motors used stationarily (e.g. conveyer belt drives in industrial applications, electrical steel in a car engine is subjected to cyclic loading due to vibrations caused by the imbalance of the rotor and start and stop driving events. For a safe and reliable design of an electrical motor the fatigue behaviour of electrical steel needs to be analysed. To minimize eddy current losses, a rotor consists of several hundred electrical steel sheets with a typical thickness of less than 1 mm. Due to optimal electrical and magnetic properties a very coarse microstructure of electrical steel is required. Only one to three grains are distributed along sheet thickness. Regarding the grain size and sheet thickness the material behaviour is governed by the reaction of single grains and grain-grain-interaction to external cyclic loading. Fatigue experiments with a load ratio of R = 0.005 and R = 0.1 were carried out. They give a very flat S-N-curve where the fatigue limit is close to the yield strength of this electrical steel. Crack initiation is observed at surface roughness and areas of stress concentration resulting from manufacturing processes.

  8. The new 2.5L L4 gasoline engine for LEXUS IS300h. The renewed engine series for FR hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, Fumihisa; Mashiki, Zenichiro; Yamanari, Kenji [Toyota Motor Corporation, Aichi (Japan)

    2013-08-01

    To ensure future sustainable mobility, vehicles have to face crucial problems such as energy security, global warming and air quality. To address these problems, TOYOTA introduced in 1997 the TOYOTA Hybrid System (THS) and has continuously improved its technology, globally contributing to the environmental improvement by its expansion into many markets in the world. TOYOTA presented the renewed 4 Cylinder Engine Series for FF vehicles at this symposium last year. This year, Toyota presents the result of its continuous development for FR Hybrid Vehicles, especially for D and E segment vehicles. Toyota not only improved thermal efficiency and reduced CO{sub 2} but also achieved high power output. In 2012, TOYOTA launched 3.5L V6 engine for LEXUS-GS (2GR-FXE engine), as first engine of this new engine series. In 2013, TOYOTA will launch 2.5L-L4 engine for LEXUS-IS (2AR-FSE engine), as the leading engine of this series. Toyota developed these new engines, aiming at leadership with regard to fuel economy, clean exhaust gas and high reliability. Toyota carried out modifications, taking into account usage of Hybrid System. With targeting highest levels of environmental performance, Toyota improved the vehicle driving performances like acceleration response by the combination of enhanced engine power output and newly developed Hybrid System. One of the biggest feature of this series is new generation D-4S system, including two injectors (for Direct injection and Port injection) for each cylinder, high fuel pressure (greater than 18MPa) and high fuel flow rate. The new generation D-4S system helps achieving high performance and good thermal efficiency. Furthermore, Toyota added on Cooled EGR system to 2AR-FSE engine, contributing to lower the fuel consumption, especially in highway driving. The very low friction technology and the well proven Atkinson Cycle are also key features of this engine series. Thanks to the above features, the new engine series achieves high

  9. Overview of pressure drawdown production test results for the Japex/JNOC/GSC Mallik 5L-38 gas hydrate research well

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, S.; Carle, D. [APA Petroleum Engineering Ltd., Calgary, AB (Canada); Dallimore, S. [Geological Survey of Canada, Sidney, BC (Canada); Collett, T. [United States Geological Survey, Denver, CO (United States); Satoh, T. [Japan Petroleum Exploration Co. Ltd., Tokyo (Japan); Inoue, T. [Japan National Oil Corp., Chiba (Japan)

    2004-07-01

    Schlumberger's Modular Dynamic Tester (MDT) cased hole wireline tool was used during a pressure drawdown production test at the Mallik 5L-38 well to successfully test 3 separate hydrate intervals as well as free gas and water zones. The MDT test was initially performed to reduce reservoir pressure below the hydrate stability point, and to shut-in and observe the pressure build-up. It was assumed that the rate of gas production would be too small to measure, so the rate of hydrate dissociation would have to be inferred from changing pressure versus time data. Two important phenomena were observed during the hydrate tests: (1) free gas was produced on a steady state basis following the initial clean-up flow of water, and (2) the pressure response upon shut-in displayed porous media effects and indicated both flow contribution and pressure effects beyond the surface area of the hydrate open to the wellbore. In response to these observations, the MDT test procedures for the hydrate intervals were changed to include multiple flow and build-up periods, as well as injection and pressure fall-off periods. The factors that should be considered in interpreting the pressure transient data obtained during the MDT tests of the hydrate intervals include wellbore and perforation geometry with respect to the pressure affected area in the reservoir; radial and time dependent hydrate saturation changes which result in dynamic multiphase fluid flow, changing relative permeability, and changing system compressibility; the addition of free gas during the shut-in periods from continued hydrate dissociation; and the changing presence and character of boundaries due either to localized fractures or the limit of the hydrate dissociation front. Since analytical pressure transient analysis software cannot incorporate such dynamic reservoir parameters, conventional analytical techniques were used to evaluate the test data. 1 fig.

  10. Determination of the non-recrystallization temperature (TNR) in multiple microalloyed steels

    Science.gov (United States)

    Homsher, Caryn Nicole

    Rolling mill metallurgists must be able to easily and accurately determine critical temperatures such as the non-recrystallization temperature (T NR) to properly plan rolling schedules for desired properties. Microalloyed steels have small additions of alloying elements such as V, Ti, and Nb, to improve mechanical properties through grain size control and precipitation strengthening. The value of TNR is based on both alloying elements and deformation parameters. To easily predict TNR, equations have been developed and utilized in the literature and industry. However, each equation has certain limitations which constrain its applicability. This study was completed using ten laboratory grade low-carbon microalloyed steels designed to meet the API X-70 specification with varying amounts of V, Nb, and Ti. Double-hit deformation tests were conducted on a Gleeble® 3500 system in the standard pocket-jaw configuration at the Colorado School of Mines to determine experimental values of TNR. Double-hit deformation tests involve cylindrical specimens in an axisymmetric compression test. The test method requires six steps: 1) reheat to ensure most precipitates dissolve back into solution, 2) cool to deformation temperature, 3) compress with given strain and strain rate, 4) hold for interpass time, 5) deform specimen again holding everything else constant, and 6) measure the percent recrystallized or percent fractional softening. The TNR is the temperature where fractional softening is equal to 20 %. Niobium plays the largest role in influencing TNR. Complex niobium-vanadium-carbonitride precipitates are believed to play a significant role increasing TNR in the Hi-V alloy The experimental values of TNR were compared with predicted values of TNR from four equations in the literature. The Bai 2011 equation was the most reliable of the existing empirical formulas considered, while the commonly used Boratto equation was not accurate in predicting the TNR for the alloys in this

  11. Tensile and impact behaviour of sinter-forged Cr, Ni and Mo alloyed powder metallurgy steels

    International Nuclear Information System (INIS)

    Sintered and forged low-alloy P/M steels containing Cr, Ni and Mo were subjected to tensile, hardness and impact tests, in order to understand the influence of the alloying elements and microstructure on their mechanical properties. Elemental powders of atomized iron, graphite, chromium, nickel and molybdenum were mixed in suitable proportions using a ball mill, compacted and sintered in order to yield the following alloy compositions: Fe-0.2%C, Fe-0.2%C-1%Cr, Fe-0.2%C-1%Cr-2%Ni, Fe-0.2%C-2%Ni and Fe-0.2%C-2%Ni-1.5%Mo. Cylindrical compacts of 24 mm diameter and 32 mm height were prepared from the powder mixes in a 1000 kN hydraulic press using suitable cylindrical die-punch combination. Sintering of the ceramic-coated cylindrical preforms was carried out at 1000 ± 10 oC in a muffle furnace for a period of 120 min. Immediately after sintering, the cylindrical compacts were hot upset forged and drawn into square cross-section bars of density values to near-theoretical using a 2000 kN friction screw press. The size of the bars was maintained as 10 x 10 x 110 mm for preparing tensile specimen and 12 x 12 x 70 mm for impact specimen. Standard tensile and impact specimens were machined off from the forged square rods. Standard procedure was followed for conducting tensile test and impact test on the forged alloys. Hardness of the hot forged alloys was also measured using Rockwell hardness tester. Microstructures of the alloys were examined for correlating with the mechanical properties. Fractographs of the fractured surfaces of the tensile specimens were obtained using a scanning electron microscope. From the present study, it is contended that the alloying elements Cr, Ni and Mo have strong influence on the tensile and impact properties of the low-alloy steels studied. Among all the five alloys considered, the steel with chromium addition has exhibited the highest tensile strength with the corresponding impact strength being the least. The same alloy has also been

  12. Properties of hot rolled steels for enamelling

    International Nuclear Information System (INIS)

    The results of an investigation of the structure and properties of experimental produced hot rolled steels suitable for enamelling are presented in the paper. Hot rolled steels for enamelling represent a special group of the steels for conventional enamelling. Their quality has to be adapted to the method and conditions of enamelling. Therefore, these steels should meet some specific requirements. In addition to usual investigation of the chemical composition and mechanical properties, microstructure and quality of the steel surface also were investigated. The basic aim was to examine steels capability for enamelling, i. e. steels resistance to the fish scales phenomena, by trial enamelling, as well as quality of the steel - enamel contact surface, to evaluate the binding. Also, the changes of the mechanical properties, especially the yield point, during thermal treatment, as a very specific requirement, were investigated, by simplified method. Good results were obtained confirming the steels capability for enamelling. (Original)

  13. THE STRUCTURAL ANALYSIS OF STEEL SILOS WITH CYLINDRICAL-WALL BEARING AND PROFILE-STEEL BEARING

    Directory of Open Access Journals (Sweden)

    Zhengjun Tang

    2015-04-01

    Full Text Available The silos are widely used in bulk material in many fields such as agriculture, mining, chemical, electric power storage, etc. Thin metal cylindrical silo shells are vulnerable to buckling failure caused by the compressive wall friction force. In this paper, the structural analysis of two types of steel silo with cylindrical-wall bearing and profile-steel bearing is implemented by Abaqus finite element analysis. The results indicate that under the same loading conditions, steel silos with profile-steel bearing and cylindrical-Wall bearing have similar values in Mises stress, but the steel silo with profile-steel bearing has a smaller radial displacement and a better capability of buckling resistance. Meanwhile, the total steel volumes reduced 8.0% comparing to the steel silo with cylindrical-wall bearing. Therefore, steel soil with profile-steel bearing not only has a less steel volumes but also a good stability.

  14. Review on Cold-Formed Steel Connections

    Directory of Open Access Journals (Sweden)

    Yeong Huei Lee

    2014-01-01

    Full Text Available The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

  15. Review on cold-formed steel connections.

    Science.gov (United States)

    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  16. Carbon Segregation of Bearing Steel Concasting Billet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The formation mechanism of “white band” and central carbon segregation of high-carbon Cr bearing steel concasting billets are discussed in this paper. The maximum oxygen content in the steel produced by concasting process was 13x10-6 with an average oxygen content of 9.3x 10-6.Comparison of metallurgical quality and fatigue property between the concasting steel (CC) andingot casting steel (IC) showed that the carbon segregation (C/C0) in former steel was 0.92~1.10and its fatigue life was equal to that of the latter steel.

  17. Review on Cold-Formed Steel Connections

    Science.gov (United States)

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  18. Microbial corrosion of stainless steel.

    Science.gov (United States)

    Ibars, J R; Moreno, D A; Ranninger, C

    1992-11-01

    Stainless steel, developed because of their greater resistance to corrosion in different aggressive environments, have proved to be affected, however, by various processes and types of corrosion. Some of these types of corrosion, mainly pitting, is activated and developed in the presence of microorganisms, which acting in an isolated or symbiotic way, according to their adaptation to the environment, create a favorable situation for the corrosion of these steel. The microorganisms that are involved, mainly bacteria of both the aerobic and anaerobic type, modify the environment where the stainless steel is found, creating crevices, differential aeration zones or a more aggressive environment with the presence of metabolites. In these circumstances, a local break of the passive and passivating layer is produced, which is proper to these types of steel and impedes the repassivation that is more favorable to corrosion. In the study and research of these types of microbiologically influenced corrosion are found electrochemical techniques, since corrosion is fundamentally an electrochemical process, and microbiological techniques for the identification, culture, and evaluation of the microorganisms involved in the process, as well as in the laboratory or field study of microorganism-metal pairs. Microstructural characterization studies of stainless steel have also been considered important, since it is known that the microstructure of steel can substantially modify their behavior when faced with corrosion. As for surface analysis studies, it is known that corrosion is a process that is generated on and progresses from the surface. The ways of dealing with microbiologically influenced corrosion must necessarily include biocides, which are not always usable or successful, the design of industrial equipment or components that do not favor the adherence of microorganisms, using microstructures in steel less sensitive to corrosion, or protecting the materials. PMID:1492953

  19. Kinetics of borided gear steels

    Indian Academy of Sciences (India)

    Ibrahim Gunes

    2013-06-01

    In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigated.

  20. Towards Responsible Steel: Preliminary Insights

    Directory of Open Access Journals (Sweden)

    Suzanne Benn

    2014-03-01

    Full Text Available This paper examines the structures and processes underpinning the attempt of the Australian steel industry to establish a certification scheme for Responsible Steel. We take it as a case example of how collective action and collaboration along a supply chain has the potential to be a win-win situation for the environment and for the competitiveness of an industry sector. The paper identifies the drivers that have prompted key stakeholders from all major sectors of the Australian steel product life cycle from mining through steel manufacturing, processing, product fabrication, use and re-use, and recycling to collaborate in the establishment of the Steel Stewardship Forum (SSF, the structure established to lead the development of the certification scheme. The development of this initiative is indicative of the wider shift to sustainability-related certification schemes as a means of garnering legitimacy and market advantage and provides detailed insights into both the drivers for and the challenges associated with such initiatives. Findings from the paper contribute to our understanding of the shift to sustainable supply chains as it is interpreted through institutional and institutional entrepreneurship theory.

  1. Steel erected at A-3 Test Stand

    Science.gov (United States)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  2. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    OpenAIRE

    Mehanna, Maha; Basséguy, Régine; Délia, Marie-Line; Bergel, Alain

    2009-01-01

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (Eoc) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of Eoc ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended ess...

  3. Heat treatment of supermartensitic steels

    International Nuclear Information System (INIS)

    Low carbon supermartensitic 13% Cr steels with 4-6%Ni and 0-2.5%Mo additives have been developed from type AISI 420 steels for applications in the oil industry. They offer significantly better weldability, improved general corrosion resistance, particularly in carbon dioxide environments, and some grades exhibit improved resistance to sulphide stress corrosion cracking. In this paper results of detailed investigations on a 13Cr-6Ni-2,5Mo-Ti steel after quenching and double tempering are presented. Microstructural studies were carried out using optical microscopy, transmission electron microscopy and X-ray diffractometry. The results prove the formation of austenite during tempering at both 690 and 620 oC is accompanied by intensive precipitation of Fe2Mo Laves phase particles. (author)

  4. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    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)

  5. Optimum design of steel structures

    CERN Document Server

    Farkas, József

    2013-01-01

    This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...

  6. Nonmetallic inclusions in HSLA steel weldments

    OpenAIRE

    Douglas, Brent A.

    1989-01-01

    Approved for public release; distribution is unlimited The U.S. Navy is currently funding a program for certification of HSLA steels to replace the HY series of high strength steels for structural fabrication. Integral to this program is the certification of welding consumables for use with these steels. The size, distribution and composition of nonmetallic inclusions in HSLA steel weld metal has been shown to play a key role in the final strength and toughness of the deposited weld. Th...

  7. Optimising steel hub location in Thailand

    OpenAIRE

    Sakaradhorn Boontaveeyuwat

    2012-01-01

    The optimal location of a steel hub in Thailand was analysed by applying aspecific research methodology designed to evaluate locations near the seaports. The growth of Thailand’s steel industry has become a centre of attention in the last decade, resulting in substantial efforts to form a distribution service centre to minimise the logistic costs associated with handling large steel flows in the future. The main analysis of the steel hublocation focused on areas situated near Laem Cha Bang, M...

  8. DP 600 steel research of dynamic testing

    OpenAIRE

    M. Mihaliková; Német, M.; Girman, V.

    2015-01-01

    Dynamic tensile testing of sheet steels is becoming more important due to the need for more optimized vehicle crashworthiness analysis in the automotive industry. For generating data in dynamic conditions, was using different assay techniques. DP (dual phase) steel is suitable for large complicated shape such as fenders, doors, bumpers and roofs. For experiments was used two testing method servo hydraulic and single bar method. Experiments were realized on steel grade DP 600. Steel were perfo...

  9. Microstructural Development during Welding of TRIP steels

    OpenAIRE

    Amirthalingam, M.

    2010-01-01

    The Advanced High Strength Steels (AHSS) are promising solutions for the production of lighter automobiles which reduce fuel consumption and increase passenger safety by improving crash-worthiness. Transformation Induced Plasticity Steel (TRIP) are part of the advanced high strength steels which offers a high strength and toughness combination with excellent uniform elongation. However, the higher alloying content of these steel limits their weldability and the thermal cycle of a welding proc...

  10. Multicomponent Synthesis and Evaluation of New 1,2,3-Triazole Derivatives of Dihydropyrimidinones as Acidic Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Rodrigo González-Olvera

    2016-02-01

    Full Text Available An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf3 as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.

  11. Multicomponent Synthesis and Evaluation of New 1,2,3-Triazole Derivatives of Dihydropyrimidinones as Acidic Corrosion Inhibitors for Steel.

    Science.gov (United States)

    González-Olvera, Rodrigo; Román-Rodríguez, Viridiana; Negrón-Silva, Guillermo E; Espinoza-Vázquez, Araceli; Rodríguez-Gómez, Francisco Javier; Santillan, Rosa

    2016-02-22

    An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf)₃ as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.

  12. Intramolecular electron transfer in mixed-valence complexes [(NH3)5Ru-L-Ru(NH3)5]5+ (L = N2, pyz, pym, 4,4'-bipy, bpa)

    Science.gov (United States)

    Sizova, O. V.; Baranovskii, V. I.; Panin, A. I.; Ivanova, N. V.

    2002-02-01

    The dynamics of the intramolecular electron transfer from Ru(II) to Ru(III) in binuclear mixed-valence complexes [NH3)5Ru -L-Ru(NH3)5]5+ (L = N2, pyz, bipy, pym, bpa) is analyzed by the semiempirical CINDO + CI method.

  13. Sulfide stress cracking of pipeline steels

    International Nuclear Information System (INIS)

    The problem of the sulfide stress corrosion cracking of pipeline steels and their welded joints have been presented for pipeline steels. Results of hydrogen sulfide stress cracking inhibitors and corrosion inhibitors of three types protective actions on pipeline steels of two grades petroleum range of products are given. (author)

  14. Microstructural Development during Welding of TRIP steels

    NARCIS (Netherlands)

    Amirthalingam, M.

    2010-01-01

    The Advanced High Strength Steels (AHSS) are promising solutions for the production of lighter automobiles which reduce fuel consumption and increase passenger safety by improving crash-worthiness. Transformation Induced Plasticity Steel (TRIP) are part of the advanced high strength steels which off

  15. Clean Production of Steel and Refractories in China′s Steel Industry

    Institute of Scientific and Technical Information of China (English)

    SUTiansen

    2002-01-01

    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry,environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China′s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China′s steel industry.

  16. Maraging steel - highest strength steels with simple heat treatment for difficult application purposes

    International Nuclear Information System (INIS)

    The lecture concerns the composition of the 18% NiCoMo (maraging) steels, the conversion behaviour and influence of various alloy elements, thermal treatment and its influence on the change of dimension behaviour; comparison of the thermal treatment of maraging steels with tempering steels, influence of trace elements and the way of melting on the mechanical properties, advantages and disadvantages of this group of steel, introduction of newer high-strength maraging steels, their composition and mechanical properties. (orig.)

  17. Compresibility and sinterability of HCx PM steel diluted with stainless steels

    OpenAIRE

    Gordo Elena; Khattab Nermein Hamid; Ruiz-Navas Elisa María

    2003-01-01

    HCx powder metallurgy steel contains in its composition high contents of Cr and C, and significant quantities of alloy elements typical of tool steels (Mo, V, W), to provide the corrosion resistance of stainless steel with wear resistance of tool steels. HCx appears to be a suitable material for applications in aggressive environments, as valve seat inserts in automotive engines. However, this steel presents a low compressibility leading to high production costs. In this work, some results ca...

  18. Prediction of quenched and tempered steel and cast steel properties

    Directory of Open Access Journals (Sweden)

    B. Smoljan

    2011-12-01

    Full Text Available Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was found out that yield strength is insensitive on differences between applied manufacturing processes, but by application of hot working and with appropriate pouring temperature the Charpy-V notch toughness is increased. Also, Charpy-V notch toughness is increased by interactive effect of the appropriate cooling rate during the casting and application of hot working.Research limitations/implications: The research was focused mainly on Charpy-V notch toughness of carbon and low alloyed heat treatable steels.Practical implications: The established algorithms can be used for prediction of tensile strength, yield strength and Charpy-V notch toughness in heat treating practice.Originality/value: Original relation for prediction of quenched and tempered steel and cast steel Charpy-V notch toughness are developed.

  19. Remagnetization and Cementation of Unconsolidated Sediments in the Mallik 5L-38 Well (Canadian Arctic) by Solute Exclusion During Gas Hydrate Formation

    Science.gov (United States)

    Hamilton, T. S.; Enkin, R. J.; Esteban, L.

    2007-05-01

    Bulk magnetic properties provide a sensitive measure of sedimentary diagenesis related to the stability and growth of gas hydrates. The deposit at Mallik (Mackenzie Delta, Canadian Arctic) occurs in unconsolidated Tertiary sands, but is absent in interstratified silt layers. A detailed sampling of the JAPEX/JNOC/GSC Mallik 5L-38 core tested the use of magnetic properties for detecting diagenetic changes related to the hydrate. Petrographic studies reveal that the sands are well sorted and clean, with quartz > chert >> muscovite and little fines content. Excepting a few rare bands of indurated dolomite in the midst of the gas hydrate zone, there is little or no cementation in the sands. Detrital magnetite is the dominant magnetic mineral, comprising up to a few percent of the sand grain population. In contrast, the muddier layers have a somewhat different detrital grain composition, richer in lithic (sedimentary and metamorphic) grains, feldspar, and clays. They are extensively diagenetically altered (to as much as 30- 40%) and cemented with carbonates, clays, chlorite and the iron sulphide greigite (the dominant magnetic mineral). The greigite is recognized by its isotropic creamy-white reflectance, cubic to prismatic habit, and characteristic tarnish to faintly bluish bireflectant mackinawite. Habits range from disseminated cubes and colliform masses to inflationary massive sulphide veins and clots. Rare detrital grains of magnetite were observed among the silt grains, but never in a reaction relationship or overgrown. Instead the greigite has nucleated separately, in tensional fractures and granular masses up to 4 mm across. In this particular sediment sequence, being so quartz and chert rich, there is insufficient local source for the introduced cements (calcite, dolomite, greigite, clays, jarosite), so ions must have been introduced by fluid flow. Magnetic studies reveal a bi-modal character related to the lithology (sands versus silts) and their magnetic

  20. Theoretical and Experimental on Carbon Dioxide Sequestration Degree of Steel Slag

    Institute of Scientific and Technical Information of China (English)

    LI Jian-li; ZHANG Hui-ning; XU An-jun; CUI Jian; HE Dong-feng; TIAN Nai-yuan

    2012-01-01

    The limitation and experimental CO2 sequestration degree of steel slag is the focus. The theoretical and the practical COe sequestration degree was assessed under mild operating conditions. After calculation in theory, it can be found that the CO2 sequestration limitation degree for every kilogram steel slag is about 442 g when taking magne- sium into consideration, and the experimental CO2 sequestration degree for every kilogram slag is about 77 g, under the conditions that the liquid to solid ratio is 50 L/kg, CO2 flow is 0.5 L/min and the temperature of reaction is the ambient temperature. When solution NH4Cl and CHa COOH for experiments and other conditions keep the same, the actual potential CO2 sequestration for every kilogram slag is 69.3 g and 31.20 g respectively. Thus, optimization of process parameters like granularity of slag is necessary to enhance the carbon dioxide sequestration degree for steel slag.

  1. Study of pitting corrosion in line-pipe steel under the influence of remanent magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J.H.; Caleyo, F.; Hallen, J.M. [Instituto Politecnico Nacional (IPN), Zacatenco (Mexico)

    2009-07-01

    The influence of remanent magnetization on pitting corrosion in line-pipe steels is studied. Pitting corrosion experiments have been carried out on samples of an API 5L grade 52 steel under a magnetization level of the same order of magnitude of the remanent magnetization in the pipeline wall after in-line inspection based on magnetic flux leakage. The samples were magnetized using rings of the same grade as the investigated steel. Immediately after magnetization, the investigated samples were subjected to pitting by immersing them in a solution containing dissolved Cl{sup -} and SO{sup 2-}{sub 4} and ions. The pitting experiments were conducted during a seven days period. The pit depth distribution and the maximum pit depth in each sample were recorded and used to conduct extreme value analyses of the pitting process in magnetized and non-magnetized control samples. The statistical assessment of the pitting corrosion data collected during this study shows that the magnetic field reduces the average depth of the pit population and also the extreme pit depth values that can be predicted from the maximum values observed in the magnetized samples in comparison with to the non-magnetized control samples. Scanning electron microscopy observations show that the magnetic field alters the pit morphology by increasing the pit mouth opening. (author)

  2. Preformed posterior stainless steel crowns: an update.

    Science.gov (United States)

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  3. Advanced sheet steels for automotive applications

    Science.gov (United States)

    Fekete, James R.; Strugala, Donald C.; Yao, Zhicong

    1992-01-01

    Vacuum degassing has recently been used by sheet steel producers to improve their products' ductility and strength. Carbon contents can be reduced by an order of magnitude to less than 0.0030 wt.%. Through careful alloying and processing, a range of new steel products has been developed for the automotive industry. These products include interstitial-free, deep-drawing-quality steels; formable, high-strength, interstitial-free steels; and bake-hardenable steels. This article summarizes the chemistry and processing needed to produce these products.

  4. Imaging molten steel flow profiles

    Science.gov (United States)

    Binns, R.; Lyons, A. R. A.; Peyton, A. J.; Pritchard, W. D. N.

    2001-08-01

    Control of delivery of molten steel in continuous casting is critical in order to ensure stability of the meniscus and satisfactory mould flow patterns, which in turn are determinants of cleanness and surface quality of steel. Considerable effort has been expended over the last ten years on optimizing the design of the metal delivery system, particularly the pouring nozzle, in order to allow the consistent production of high quality steel at a high throughput. This paper looks forward to possible systems that are capable of tomographically imaging the distribution of molten steel flows in these applications. The paper will concentrate on the feasibility of using electromagnetic methods. The paper will present some initial results; an overview of the applied image reconstruction process will also be included. The paper will conclude with a discussion of possible future developments, such as the use of a tomographic or multi-frequency approach, future research on the reconstruction image procedures and the potential for visualization and flow measurement. There is a need for further research in this area and some priority areas for future work will be suggested.

  5. Ultrasonic determination of steel structures

    International Nuclear Information System (INIS)

    In the research project 'Determination of steel structures by means of ultrasound' methods are developed for the non-destructive structure characterization with scattered ultrasound. Measurements were made at about 200 steel samples with frequencies between 5 and 20 Mc/sec. In the range of 0,05 <= d/lambda <= 0,5 (d=mean grain size, lambda = wavelength of the ultrasound pulse) known theories can be applied for the quantitative grain size determination and with an accuracy of +-15% the results agree with the metallographically measured values. The best method for this is the combination of two measurements with two different frequencies. Advantages are given by the measurement of the multiple scattering which is leading to the scattering coefficient and to the grain size with one measurement only and without assumptions concerning other parameters of ultrasound propagation. A structure characterization concerning the homogeneity inside the material is possible, too, because of the time (i.e. sound path-)-dependent scattering measurement. It is able to control the structure of monophasic steels with grain sizes between ASTM 1 and ASTM 11. Today problems unsolved are the martensitic steels, the multiphasic structures

  6. Study on cementitious properties of steel slag

    Directory of Open Access Journals (Sweden)

    Zhu G.

    2013-01-01

    Full Text Available The converter steel slag chemical and mineral components in China’s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for “Steel Slag Powder Used For Cement And Concrete”, “Steel Slag Portland Cement”, “Low Heat Portland Steel Slag Cement”, “Steel Slag Road Cement” in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

  7. Corrosion behavior of 2205 duplex stainless steel.

    Science.gov (United States)

    Platt, J A; Guzman, A; Zuccari, A; Thornburg, D W; Rhodes, B F; Oshida, Y; Moore, B K

    1997-07-01

    The corrosion of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical and immersion (crevice) corrosion tests in 37 degrees C, 0.9 wt% sodium chloride solution. Electrochemical testing indicates that 2205 has a longer passivation range than 316L. The corrosion rate of 2205 was 0.416 MPY (milli-inch per year), whereas 316L exhibited 0.647 MPY. When 2205 was coupled to 316L with equal surface area ratio, the corrosion rate of 2205 reduced to 0.260 MPY, indicating that 316L stainless steel behaved like a sacrificial anode. When 316L is coupled with NiTi, TMA, or stainless steel arch wire and was subjected to the immersion corrosion test, it was found that 316L suffered from crevice corrosion. On the other hand, 2205 stainless steel did not show any localized crevice corrosion, although the surface of 2205 was covered with corrosion products, formed when coupled to NiTi and stainless steel wires. This study indicates that considering corrosion resistance, 2205 duplex stainless steel is an improved alternative to 316L for orthodontic bracket fabrication when used in conjunction with titanium, its alloys, or stainless steel arch wires. PMID:9228844

  8. Erosion behaviour of hydro turbine steels

    Indian Academy of Sciences (India)

    Akhilesh K Chauhan; D B Goel; Satya Prakash

    2008-04-01

    The martensitic stainless steel (termed as 13/4) is currently being used for fabrication of underwater parts in hydroelectric projects. There are, however, several maintenance problems associated with the use of this steel. A nitronic steel (termed as 21–4–N) has been developed as an alternative with the specific aim of overcoming these problems. A comparative study has been made on the erosion behaviour of 13/4 and 21–4–N steels by means of solid particle impingement using gas jet. The eroded surfaces after erosion tests were analysed by scanning electron microscopy. It is observed that the 21–4–N nitronic steel possesses better resistance to erosion in comparison to 13/4 martensitic stainless steel. The austenitic matrix of the nitronic steel possesses high hardness, high tensile toughness and work hardening ability, which results in higher erosion resistance.

  9. Plate Rolling Modeling at Mill 5000 of OJSC ``Magnitogorsk Iron and Steel'' for Analysis and Optimization of Temperature Rates

    Science.gov (United States)

    Salganik, V.; Shmakov, A.; Pesin, A.; Pustovoytov, D.

    2010-06-01

    Modeling of strip deflected mode and thermal state in rolling is an integral part of the technology and perspective rolling-mill machinery such as plate mill 5000 of the OJSC "Magnitogorsk Iron and Steel". To comprehend metal behavior in the deformation zone in the rough passes during plate rolling it is essential to assess the impact of various temperature factors on variations in field of stress and strain intensities as well as temperature fields in deformation. To do such researches in consideration of various software products and adequate results one of the most effective methods nowadays is regarded as the method of finite elements. The research shows modeling of roughing rolling of a pipe steel sheet with strength category X80 according to standard API-5L. In the research of the metal deflected mode software product DEFORM 2D has been used for the isothermal and nonisothermic process. The mathematical modeling allows revealing the impact of temperature field on the metal deflected mode in the rough passes in plate rolling. Supposedly, it is deformation heating that can have more impact on the ingot temperature profile in the finishing passes in controlled rolling of the pipe steel grades. It is defined by high percent reduction, rolling speeds; more area of heat exchange surface; less thickness and lower temperature of rolling. The results can be used to develop efficient modes of plate rolling of the pipe steels.

  10. Mechanical characteristics of fused cast basalt tube encased in steel pipe for protecting steel surface

    Institute of Scientific and Technical Information of China (English)

    Jee-Seok WANG; Jong-Do KIM; Hee-Jong YOON

    2009-01-01

    Because of the various excellent characteristics of cast basalt materials, such as, anti-corrosion, anti-wearing, good hardness, high chemical stability, of which steel may not possess, the steel-basalt composite pipes are used in severe environments for compensating the defects of steel. The limit of bending moment with which steel-basalt composite pipe may safely endure was calculated and the limit curvature of the composite pipe in the safe range was presented. The application temperature of steel-basalt pipe was examined due to a different coefficient among basalt, mortar and mild steel.

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

    Science.gov (United States)

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

    2016-08-01

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

  12. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    OpenAIRE

    Syed Altaf Khalid; Vadivel Kumar; Prithviraj Jayaram

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets - titanium, self-ligating stainless steel, and conventional stainless steel - using stainless steel archwires and TMA archwires. An in vitro study of simulated ca...

  13. Bimetallic layered castings alloy steel – carbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-01-01

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

  14. Prediction of quenched and tempered steel and cast steel properties

    OpenAIRE

    B. Smoljan; D. Iljkić; H. Novak

    2011-01-01

    Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was ...

  15. Cleanliness of Alloying Structural Steel

    Institute of Scientific and Technical Information of China (English)

    YU Hui-xiang; WANG Xin-hua; ZHANG Jing; LI Hai-bo; WANG Wan-jun

    2011-01-01

    Alloying structural steel used for mechanical structures has a high requirement for cleanliness because its failures are greatly affected by non-metallic inclusions and total oxygen content in steel.It has been reported by some steelmaking plants to have some problems in controlling total oxygen content and inclusions during alloying structural steel production.For this purpose,cleanliness control in 0.2C-0.3Si-0.6Mn-1Cr-0.2Mo steel was investigated.Firstly,low melting temperature zone(≤1873 K) of CaO-Al2O3-MgO system and formation condition of low melting temperature inclusions were investigated through thermodynamic equilibrium calculation.On this basis,industrial tests were carried out.Through sampling at different stages,transformation of oxide inclusions and change of total oxygen content in steel were studied.The results show that:in order to form CaO-Al2O3-MgO system inclusions with low melting temperature,mass percent of Al2O3,MgO and CaO in inclusions should be controlled from 37.6% to 70.8%,0 to 17.4% and 25.5% to 60.6%;For the condition of 1873 K and 0.05%(mass percent) dissolved aluminum in steel,the activities of dissolved oxygen,magnesium and calcium should be controlled as 0.298×10-4-2×10-4,0.1×10-5-40×10-5 and 0.8×10-8-180×10-8 respectively.With secondary refining proceeding,average total oxygen content and inclusion amount decrease,the type of most inclusions changes from Al2O3 after tapping to Al2O3-MgO after top slag is formed during ladle furnace refining and finally to CaO-Al2O3-MgO after RH treatment.In the final products,average total oxygen content was 12.7×10-6 and most inclusions were in spherical shape with size less than 5 μm.

  16. CO2 corrosion resistance of carbon steel in relation with microstructure changes

    International Nuclear Information System (INIS)

    The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO2 was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to characterize the formation of the corrosion product layers. Electrochemical results revealed that corrosion resistance increased in the following order: B < N < Q&T < A. From the polarization curves it was shown that specifically, cathodic current densities were affected by microstructural changes. SEM images indicated that ferrite dissolved earlier than cementite and a thin layer of corrosion products was deposited on the steel surface. XPS analyses revealed that this layer was composed of a mixture of iron carbonate and non-dissolved cementite. It was also found that the quantity of FeCO3 content on the steel surface was greater for Q&T and A microstructures. These results, in agreement with the electrochemical data, indicate that the deposition mechanism of iron carbonate is closely related to the morphology of the non-dissolved cementite, determining the protective properties of the corrosion product layers. - Highlights: • The effect of change in microstructure on CO2 corrosion resistance was evaluated. • An API 5LX 42 carbon steel was immersed in a 0.5 M NaCl solution saturated with CO2. • Banded, normalized, quenched-tempered and annealed microstructures were considered. • Electrochemical measurements were coupled with surface analysis. • Morphology and distribution of undissolved Fe3C control corrosion kinetics

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  18. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    Science.gov (United States)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  19. Steel Safeguards and the Welfare of U.S. Steel Firms and Downstream Consumers of Steel: A Shareholder Wealth Perspective

    OpenAIRE

    Liebman, Benjamin H.; Kasaundra M. Tomlin

    2006-01-01

    This paper analyzes the steel safeguards implemented and subsequently removed during 2001-2003. Our results reveal that for shareholders of U.S. steel companies, safeguards generated positive “abnormal” returns of approximately 6%; and the cancellation of the safeguards resulted in wealth gains of about 5%. Steel shareholders experienced negative abnormal returns of -5% in response to the WTO ruling that the U.S. violated WTO law. The results here are consistent with the neoclassical view tha...

  20. A mortality study among mild steel and stainless steel welders.

    Science.gov (United States)

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-03-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders.

  1. Niobium in engineering bar steels

    International Nuclear Information System (INIS)

    The use of niobium as a microalloying addition to hot rolled and cold finished bars offers many opportunities to achieve enhanced mechanical properties in a very cost effective manner. By the addition of niobium (sometimes in combination with vanadium) to selected carbon steel grades, it is possible to produce hot rolled bars with minimum yield strengths up to 689 MPa (100 ksi) and cold finished bars with yield strengths up to 1035 MPa (150 ksi). These high-strength-low-alloy bars have a myriad of applications particularly for automotive parts such as shafts, stabilizer bars, tie rods, piston rods, fasteners such as U-bolts, brackets, and various transmission parts. Of particular value has been the specification of Nb-microalloyed steels for such hot forgings as connecting rods and caps, and weld yokes a situation which has permitted elimination of post-forging heat treatment (quenching and tempering). Significant reductions in cost and energy consumption have been realized

  2. Steel Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  3. Fatigue Strength of Weathering Steel

    Directory of Open Access Journals (Sweden)

    Ludvík KUNZ

    2012-03-01

    Full Text Available Fatigue behaviour of Atmofix 52 steel (comparable to COR-TENâ steel exposed to atmospheric corrosion for 20 years was investigated. S-N curves for load symmetrical cycling and cycling with stress ratio R = 0 were determined on specimens detracted from a failed transmission tower. The data were compared with those on material without a rust layer. The fracture surfaces and, in particular, the sites of fatigue crack initiation were analyzed. Substantial decrease of fatigue life and fatigue limit due to corrosion exposition was found. Based on observation of surface layer with corrosion products and on fractographic analysis of failed specimens conclusions on fatigue damage mechanism were drawn. No grain boundary corrosion, which can be responsible for fatigue crack initiation, was observed. Initiation of fatigue cracks was related to surface roughness and took place exclusively on corrosion dimples.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1335

  4. Steel Industry Marginal Opportunity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2005-09-01

    The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

  5. Benchmarking in Mobarakeh Steel Company

    Directory of Open Access Journals (Sweden)

    Sasan Ghasemi

    2008-05-01

    Full Text Available Benchmarking is considered as one of the most effective ways of improving performance incompanies. Although benchmarking in business organizations is a relatively new concept and practice, ithas rapidly gained acceptance worldwide. This paper introduces the benchmarking project conducted in Esfahan’s Mobarakeh Steel Company, as the first systematic benchmarking project conducted in Iran. It aimsto share the process deployed for the benchmarking project in this company and illustrate how the projectsystematic implementation led to succes.

  6. Ultra high strength in steel.

    Directory of Open Access Journals (Sweden)

    V. R. Parameswaran

    1962-07-01

    Full Text Available Very high strength levels in steel, not obtained by conventional methods of hardening by quenching and low temperature tempering, are obtained by mew hardening techniques involving the thermal-mechanical treatment of metastable austenite.The earlier attempts on such hardening techniques and the development of new processes such as 'Ausforming' investigated in the Ford Motor Company Research Laboratories and ''Maraging'' developed and patented by the International Nickel Company (MondLimited, are briefly reviewed here.

  7. Nano-composite stainless steel

    Science.gov (United States)

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  8. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, Manuel; Fuente, Daniel de la; Díaz Ocaña, Iván; Cano, Heidis

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morpholog...

  9. Metadynamic recrystallization in C steels

    Indian Academy of Sciences (India)

    A R Morgridge

    2002-08-01

    Metadynamic recrystallization has been investigated in three plain carbon steels (ENIA, EN2 and EN24) through the use of hot interrupted compression tests on a wedge plastometer. Holding time was 0.5 s between passes. Strain rates of 0.05 and 0.12/s and small strain increments of 3, 5 and 7% were employed. Test temperatures were varied between 800 and 1100°C. Various incremental and continuous stress strain curves were highlighted at different temperatures and strain rates for 3 steels, ENIA, EN2 and EN24, resulting in varying flow stresses and strains. Highest peak stress was 180 MPa for EN24 at peak strain of 0.25 and 900°C, with a strain rate 0.12/s. Peak strain values for all steels at 1100°C was 0.133 at a strain rate of 0.05/s and 0.15 at a strain rate of 0.12/s. Strain accumulation resulted in dynamic and metadynamic recrystallization with refinement to about 15 m for dynamic and 22 m for metadynamic recrystallization. Fractional softening, , decreased from 0.27 to 0.12 as recrystallization times in metadynamic recrystallization increased from 0.9 s to 1.5 s at 1100°C. Time for 50% metadynamic recrystallization was also reduced as temperature increased. For ENIA, a drop from 10000 s to 20 s, as temperature increased from 800 to 1100 °C was observed. For EN24 and EN2 steels, a drop from 4000 s to 6 s for similar temperature rise was observed. Metadynamic recrystallization (at strains higher than critical strain) is observed to be a strong function of strain rate and a very weak function of temperature and strain. It significantly refined the austenite grain size prior to transformation.

  10. Microstructural degradation of bearing steels

    OpenAIRE

    Solano Alvarez, Wilberth

    2015-01-01

    The aim of the work presented in this thesis is to clarify one of the most fundamental aspects of fatigue damage in bearings steels through critical experiments, in particular whether damage in the form of cracks precedes hard ?white-etching matter" formation, which is carbon supersaturated nanoscaled ferrite. Heat treatments have been designed to create four different crack types and distributions: scarce martensite plate cracks, fine grain boundary cracks, abundant martensite plate cracks, ...

  11. Austenitic Oxide Dispersion Strengthened Steels : A Review

    Directory of Open Access Journals (Sweden)

    Lavanya Raman

    2016-06-01

    Full Text Available Materials play an important role in the fast breeder reactors.  Materials used in cladding tube and fuel pins should have better creep and void swelling resistance. To overcome these difficulties, a new class of material known as oxide dispersion strengthened (ODS steels are used. There are two groups of ODS steels, the ferritic and the austenitic ODS steels based on the matrix. The present paper reviews the current status of research in austenitic ODS steels. The interaction of dislocations with finely dispersed incoherent, hard particles that governs the strength and high temperature properties of ODS materials is briefly reviewed. The synthesis route adopted for these ODS steels, which is mostly through powder metallurgy route is also discussed. The role of various oxides such as Y2O3, ZrO2and TiO2and the clusters formed in these ODS steels on the mechanical properties and void swelling characteristics is also discussed.

  12. Strengthening of nitrogen-containing maraging steels

    Energy Technology Data Exchange (ETDEWEB)

    Kaputkina, L.M.; Prokoshkina, V.G.; Uluntsev, D.Yu. [Moskovskij Inst. Stali i Splavov, Moscow (Russian Federation)

    1999-07-01

    The austenitic and austenitic-martensitic aging 15Cr(5-10)Ni2CuMoV(Nb)Ti-N - based steels were elaborated and investigated. These steels combine advantages of austenitic and martensitic steels and allow wide variety of phase compositions and mechanical properties. For nitrogen-containing austenitic and austenitic-martensitic steels it is possible to achieve, due to stress-induced martensitic transformation and thermomechanical treatment optimization, the strength level of martensitic-austenitic steels in a combination with high plasticity and fracture toughness inherent in pure austenitic structures. At the same time corrosion resistance of these steels in low-aggressive media is preserved and wear resistance increases as twice. (orig.)

  13. Fracture behavior of various welded steels

    International Nuclear Information System (INIS)

    In this study, P295GH (17Mn4) pressure vessel steel and AISI 304 stainless steel were joined by using ER 309L electrodes. Welded specimens were fatigued by four point bending experiments. Cracks occurred on the stainless steel side of the weldment during the fatigue tests. Finite element (FE) analyses were conducted by fixing 2-D precracked model for welded 17Mn4 pressure vessel steel and AISI 304 stainless steel by using ER 309L electrodes. True stress and true strain values of the AISI 304, 17Mn4 steels and ER 309L electrodes were determined by tensile tests. Stress analyses were conducted after entering the linear and nonlinear properties of the materials into software manually. Eventually, fracture mechanics analyses were conducted for the model, and J integral fracture toughness values of the crack on the weldment were calculated.

  14. Utilization of structural steel in buildings.

    Science.gov (United States)

    Moynihan, Muiris C; Allwood, Julian M

    2014-08-01

    Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

  15. Fracture behavior of various welded steels

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Tevfik Ertugrul; Cetinel, Hakan [Celal Bayar Univ., Manisa (Turkey). Dept. of Mechanical Engineering; Uyulgan, Bahadir [Dokuz Eyluel Univ., Izmir (Turkey). Dept. of Metallurgical and Materials Engineering

    2016-02-01

    In this study, P295GH (17Mn4) pressure vessel steel and AISI 304 stainless steel were joined by using ER 309L electrodes. Welded specimens were fatigued by four point bending experiments. Cracks occurred on the stainless steel side of the weldment during the fatigue tests. Finite element (FE) analyses were conducted by fixing 2-D precracked model for welded 17Mn4 pressure vessel steel and AISI 304 stainless steel by using ER 309L electrodes. True stress and true strain values of the AISI 304, 17Mn4 steels and ER 309L electrodes were determined by tensile tests. Stress analyses were conducted after entering the linear and nonlinear properties of the materials into software manually. Eventually, fracture mechanics analyses were conducted for the model, and J integral fracture toughness values of the crack on the weldment were calculated.

  16. Development and outlook of Chinese steel industry

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The fast development of Chinese steel industry has drawn great attention from the world.Market n eeding and technical development are the main driving forces for the rapid development of Chinese steel industry. Based on the discussing of the reasons of its rapid development, the present paper further analyzed the main problems and distance towards the advanced level of international steel industry. It bring forward that Chinese steel industry should enhance the research and development on new generation steel materials and production process to ensure its sustainable development. Through populating the key technologies of syntheses energy saving and water saving to realize the main equipments self-making and establish a new recyclable steel production process.

  17. Microstructures in laser welded high strength steels

    Science.gov (United States)

    Rizzi, P.; Bellingeri, S.; Massimino, F.; Baldissin, D.; Battezzati, L.

    2009-01-01

    In this work, the effect of laser welding on the microstructure was studied for three Advanced High Strength Steels: transformation induced plasticity steel (TRIP), dual phase steel (DP) and martensitic steel. Two sheets of the same steel were laser welded and a microstructural study was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. For all samples the welded zone was constituted by martensite and the heat affected zone shows a continuous change in microstructure depending on temperatures reached and on the different cooling rates. The change in mechanical properties in the welded area was followed by Vickers micro-hardness measurements. Quasi binary phase diagrams were calculated and, according to position of T0 lines, it was deduced that austenite is the primary phase forming during rapid solidification for all steels.

  18. Microstructures in laser welded high strength steels

    International Nuclear Information System (INIS)

    In this work, the effect of laser welding on the microstructure was studied for three Advanced High Strength Steels: transformation induced plasticity steel (TRIP), dual phase steel (DP) and martensitic steel. Two sheets of the same steel were laser welded and a microstructural study was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. For all samples the welded zone was constituted by martensite and the heat affected zone shows a continuous change in microstructure depending on temperatures reached and on the different cooling rates. The change in mechanical properties in the welded area was followed by Vickers micro-hardness measurements. Quasi binary phase diagrams were calculated and, according to position of T0 lines, it was deduced that austenite is the primary phase forming during rapid solidification for all steels.

  19. Plain carbon steel bipolar plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    WANG Jianli; SUN Juncai; TIAN Rujin; XU Jing

    2006-01-01

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

  20. Large deformation structural performance of double skin composite construction using British Steel's 'Bi-Steel'

    OpenAIRE

    McKinley, B.

    1999-01-01

    Double skin composite construction consists of two relatively thin steel plates with the space between filled with, usually, normal weight concrete. The transfer of shear between the steel and concrete is possible through the use of steel shear connectors that are welded to the steel plates. A study of previously published information revealed that the areas to market double skin composite construction would be submerged tube tunneling and floating offshore structures, particularly those used...

  1. Buckling of steel and composite steel and concrete columns in case of fire

    OpenAIRE

    Correia, Antonio M.; Rodrigues, João Paulo C.

    2010-01-01

    Bare steel columns are known to have a very low fire resistance. The high thermal conductivity and the sudden decrease of the steel yield stress and Young Modulus in function of the temperature are responsible for this behaviour. The purpose of this study is to compare different modes of failure of building steel columns. The buckling of the columns is strongly influenced by the contact with other elements such as brick walls. Three types of situations were compared: steel columns...

  2. Did US Safeguard Protection on Steel Affect Market Power of European Steel Producers?

    OpenAIRE

    Hylke VANDENBUSSCHE; Zarnic, Ziga

    2006-01-01

    This paper empirically investigates the effects of US safeguard protection on steel imports in 2002 on the mark-ups of EU steel producers. We identify a large panel of European steel producers between 1995 and 2004 affected by the safeguards. Using the Roeger method, our results show that US safeguards significantly reduced EU firms?mark-ups. Single-product EU steel firms suffered relatively more from the protection than multi-product firms. Controlling for firm heterogeneity, these results a...

  3. Regularity of Structural Superplasticity of Hypoeutectoid Steel

    Institute of Scientific and Technical Information of China (English)

    YANG Yun-lin; WEN Jiu-ba

    2005-01-01

    The curve of the relation between fracture elongation and temperature for unltrafine grained low alloy hypoeutectoid steels generally shows that three peaks occur at temperatures just below Ac1, between Ac1 and Ac3, and just above Ac3, When these steels are subjected to superplastic tensile test at different temperatures, the value of the last one is the lowest and the other two peaks are different one from another depending on components, microstructures and deformation conditions of the steels.

  4. Powder metallurgically produced high nitrogen steels

    Energy Technology Data Exchange (ETDEWEB)

    Liimatainen, J. [Rauma Materials Technology, Tampere (Finland)

    1999-07-01

    Nitrogen alloying of steel is a modern way of improving technical and manufacturing characteristics of stainless, high temperature and wear resistant steels. Powder metallurgy (P/M) enables nitrogen alloying in the melt during alloying or in the solid state for gas atomized powder. Especially the nitrogen alloying in the solid state provides several benefits in enhancing steel properties by nitrogen alloying. This paper describes methods of nitrogen alloying in P/M materials and shows examples of improved material properties. (orig.)

  5. Super High Strength Steel for automotive applications

    OpenAIRE

    CONFENTE, Mario; SCHNEIDER, Emmanuel; BOMONT, Olivier; LESCALIER, Christophe; BOMONT-ARZUR, Anne

    2008-01-01

    Intensive weight savings and out-sizing programs are developed in automotive industry and lead to increase the mechanical properties of the material of the automotive parts. ArcelorMittal has developed specific steel grades known as Super High Strength Steels which are designed for both high ductility and toughness and fatigue resistance. This paper investigates machinability for a drilling operation using an experimental methodology. One of the materials is a new low bainitic steel grade. Ex...

  6. Dissimilar Welding of Titanium Alloys to Steels

    OpenAIRE

    Gao, Yefei; TSUMURA, Takuya; NAKATA, Kazuhiro

    2012-01-01

    This review summarizes the dissimilar welding of titanium alloys to steels over a period of ten recent years, involving the welding processes which are used for the dissimilar welding of titanium alloys to steels, the mechanical properties of the joints and the discussion for the forming mechanism of the interface. Reducing the formation of brittle intermetallic compound (IMC) is a key requirement in the dissimilar welding of titanium alloys to steels, because the strength of the welding join...

  7. Kocel Steel Foundry Grand Opening Ceremony

    Institute of Scientific and Technical Information of China (English)

    TIAN Shi-jiang

    2006-01-01

    @@ On May 9, 2006 the Grand Opening ceremony of Kocel Steel Foundry Co., Ltd. was held in the National Economic and Technological Development Zone in Yinchuan City, Ningxia, China. Kocel Steel Foundry Co.,Ltd. is a large scale enterprise producing steel castings and it is jointly established by Ningxia Kocel Group,Changcheng Suzaki Machine & Foundry Co., Ltd. and Voestalpine Giesserei Linz GmbH, Austria.

  8. Spectral Data Processing for Steel Industry

    OpenAIRE

    Bisot, Clémence

    2015-01-01

    For steel industry, knowing and understanding characteristics of a steel strip surface at every steps of the production process is a key element to control final product quality. Today as the quality requirements increase this task gets more and more important. The surface of new steel grades with complex chemical compositions has behaviors especially hard to master. For those grades in particular, surface control is critical and difficult. One of the promising technics to assess the problem ...

  9. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  10. Sustainability assessment and standardisation : steel buildings

    OpenAIRE

    Andrade, Joana B.; Bragança, L.

    2012-01-01

    This paper aims at evaluating in what extent are the existing sustainability assessment methodologies capable of truly reward the benefits of steel-intensive buildings in comparison with other building construction solutions. This evaluation consists in describing the more common sustainability assessment methodologies from the steel construction point of view and in comparing existing assessments to steel buildings. The pros and cons of each will also be pointed out, in order ...

  11. Prevention methods against hydrogen degradation of steel

    OpenAIRE

    J. Ćwiek

    2010-01-01

    Purpose: of this paper is presentation of mechanisms and forms of hydrogen degradation in steel along with pointing out methods for hydrogen degradation prevention.Design/methodology/approach: Hydrogen degradation of steel is a form of environmentally assisted failure which is caused by the action of hydrogen often in combination with residual or applied stress resulting in reduction of plasticity, load bearing capacity of a component, and cracking.Findings: The sources of hydrogen in steel w...

  12. The heat treatment of Fermanal cast steel

    OpenAIRE

    F. Binczyk; A. Smoliński; J. Szymszal

    2007-01-01

    The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite) is the content of aluminium. The matrix totally austenitic is p...

  13. Behaviour of high strength steel moment joints

    OpenAIRE

    Girão Coelho, A.M.; Bijlaard, F.S.K.

    2010-01-01

    The design of joints to European standard EN 1993 within the semi-continuous/partially restrained philosophy is restricted to steel grades up to S460. With the recent development of high performance steels, the need for these restrictions should be revisited. The semicontinuous joint modelling can be adopted as long as the joint develops rotation capacity and behaves ductile. The research summarized in this paper focuses on moment joints with components made from high strength steel S460, S69...

  14. Hot workability of duplex stainless steels

    OpenAIRE

    Martin, Guilhem

    2011-01-01

    The Duplex Stainless Steels (DSS) are defined as a family of stainless steels consisting of a two-phase microstructure involving δ-ferrite and γ-austenite. Exceptional combinations of strength and toughness together with good corrosion resistance under critical working conditions designate DSS a suitable alternative to conventional austenitic stainless steels. Unfortunately, the relatively poor hot workability of these alloys makes the industrial processing of flat products particularly criti...

  15. RATIONAL STEEL CORRUGATED PROFILE DESIGN

    Directory of Open Access Journals (Sweden)

    V. V. Kachurenko

    2015-08-01

    Full Text Available Purpose. The work sets forth the search results of new, more efficient design solutions for metal silos, namely, the analysis of existing types of profiles cross-section in a steel wall of such silo and development of less material-intensive section of corrugated profile.Methodology. To achieve the set goal there were researched the existing types of capacitive structure profiles and their strain-stress state under the load. The analysis was performed on the results of computational experiments. The prototype object was mathematical computer models. The calculations were made using the finite-element method. For computational experiment there was used the design-computing system Structure CAD for Windows. Findings. In this work there were obtained the data allowing to assess work of the profiles and to find more effective type of cross-section in terms of its material consumption. In the process of joint study of the authors a new type of profile for capacitive structures was developed; it has higher utilization efficiency and the attachment point of individual steel sheets with this type of profile. Both solutions are easy to install, reliable in operation and can be manufactured in the conditions of modern industrial production using standard equipment, materials and components. Originality. A new type of corrugated profile cross-section for steel silo walls was proposed; it has higher load carrying capacity and rigidity and allows reducing the metal thickness without changing the structure carrying capacity that results in material consumption reduction of the whole structure.For this and similar types of profiles there was designed and proposed the attachment point of individual corrugated sheets screwed with extending flange, which enables the unit connection in case of small size corrugations, where the distance is not sufficient to accommodate the bolt cap between the individual corrugations. Practical value.Application of the proposed

  16. The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

    Science.gov (United States)

    Muzalev, V. N.; Semukhin, B. S.; Danilov, V. I.

    2016-04-01

    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications.

  17. Auburn Steel Company radioactive contamination incident

    International Nuclear Information System (INIS)

    On February 21, 1983, workers at the Auburn Steel Company, Auburn, New York discovered that about 120 tons of steel poured that day had become contaminated with 60Co. In addition to the steel, the air cleaning system and portions of the mill used in casting the steel were contaminated. Approximately 25 curies of 60Co were involved. Decontamination and disposal of the contamination cost in excess of $2,200,000. This report details the discovery of the contamination, decontamination of the plant and disposal of the contamination

  18. Laser Welding of High Strength Steels

    OpenAIRE

    Guo, Wei

    2016-01-01

    S960 and S700 are two types of high strength low alloy steels (minimum yield strengths at 960 MPa and 700 MPa, respectively) developed recently by Tata Steel. These steels are typically used in heavy lifting equipment. This research examines the feasibility and characteristics of single pass autogenous laser welding (ALW), multi-pass ultra-narrow gap laser welding (NGLW) of 8 mm thick S960 and 13 mm thick S700 high strength low alloy (HSLA) steels and compared the characteristics of the welds...

  19. Progress of Production Technology of Clean Steel in Baosteel

    Institute of Scientific and Technical Information of China (English)

    CuiJian

    2005-01-01

    The progress in control technology of carbon, nitrogen, total oxygen, phosphorus, and stdphur as well as inclusions in steel is discussed at Baosteel. The purity obtained in IF steel and pipeline steel is introduced.

  20. Steel Policy: The Good, the Bad, and the Ugly

    OpenAIRE

    Gary Clyde Hufbauer; Ben Goodrich

    2003-01-01

    While the US steel industry has been in distress for decades, the "steel crisis" of 1999-2001 was particularly acute. More than 30 steel producing and steel processing firms fell into bankruptcy between 1997 and 2001, and most of the failures occurred after President Bush took office. During his presidential campaign, Bush promised steelworkers that he would not neglect them. As the crisis worsened, the steel industry and the United Steel Workers of America (USWA) pressed the Bush administrat...

  1. Local buckling strength of steel foam sandwich panels

    OpenAIRE

    Szyniszewski, S; Schafer, BW; Smith, BH; Arwade, SR; Hajjar, JF

    2012-01-01

    The objective of this paper is to provide and verify a new design method for the in-plane compressive strength of steel sandwich panels comprised of steel face sheets and foamed steel cores. Foamed steel, literally steel with internal voids, provides enhanced bending rigidity, exceptional energy dissipation, and the potential to mitigate local instability. In this work, Winters effective width expression is generalized to the case of steel foam sandwich panels. The generalization requires mod...

  2. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Mehanna, Maha [Laboratoire de Genie Chimique, CNRS - Universite de Toulouse, 5 rue Paulin Talabot, BP1301, 31029 Toulouse (France)], E-mail: mum34@psu.edu; Basseguy, Regine; Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique, CNRS - Universite de Toulouse, 5 rue Paulin Talabot, BP1301, 31029 Toulouse (France)

    2009-11-15

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (E{sub oc}) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of E{sub oc} ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended essentially on the nature of the material. This effect was due to the capacity of G. sulfurreducens to create a direct cathodic reaction on steel surfaces, extracting the electrons directly from material. The presence of bacterial cells modified the corrosion features of mild steel and ferritic steel, so that corrosion attacks were gathered in determined zones of the surface. Local corrosion was significantly enhanced on ferritic steel. Potential ennoblement was not sufficient to induce corrosion on austenitic steels. In contrast G. sulfurreducens delayed the occurrence of pitting on 304L steel because of its capability to oxidize acetate at high potential values. The electrochemical behaviour of 304L steel was not affected by the concentration of soluble electron donor (acetate, 1-10 mM) or the amount of planktonic cells; it was directly linked to the biofilm coverage. After polarization pitting curves had been recorded, microscopic observations showed that pits propagated only in the surface zones where cell settlement was the densest. The study evidenced that Geobacter sulfurreducens can control the electrochemical behaviour of steels in complex ways that can lead to severe corrosion. As Geobacteraceae are ubiquitous species in sediments and soils they should now be considered as possible crucial actors in the microbial corrosion of buried equipment.

  3. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    International Nuclear Information System (INIS)

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (Eoc) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of Eoc ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended essentially on the nature of the material. This effect was due to the capacity of G. sulfurreducens to create a direct cathodic reaction on steel surfaces, extracting the electrons directly from material. The presence of bacterial cells modified the corrosion features of mild steel and ferritic steel, so that corrosion attacks were gathered in determined zones of the surface. Local corrosion was significantly enhanced on ferritic steel. Potential ennoblement was not sufficient to induce corrosion on austenitic steels. In contrast G. sulfurreducens delayed the occurrence of pitting on 304L steel because of its capability to oxidize acetate at high potential values. The electrochemical behaviour of 304L steel was not affected by the concentration of soluble electron donor (acetate, 1-10 mM) or the amount of planktonic cells; it was directly linked to the biofilm coverage. After polarization pitting curves had been recorded, microscopic observations showed that pits propagated only in the surface zones where cell settlement was the densest. The study evidenced that Geobacter sulfurreducens can control the electrochemical behaviour of steels in complex ways that can lead to severe corrosion. As Geobacteraceae are ubiquitous species in sediments and soils they should now be considered as possible crucial actors in the microbial corrosion of buried equipment.

  4. Effect of weld on design of steel moment-resisting connection reinforced with steel plates

    Institute of Scientific and Technical Information of China (English)

    CHEN Peng; LI Yong

    2005-01-01

    The foreign experimental and FEM research of steel moment-resisting connection reinforced with steel plates are introduced. The effect of weld on the connection design is studied in two ways including weld detail and geometrical detail of steel plates contrast to the reference drawing of connection design in China. The research shows that the weld plays an important role in the design of connections. The welds connecting reinforced plates and beam/ column flange and the plate geometry have direct influence on the performance of the connections reinforced with plates. The study is helpful to the application of design of steel moment-resisting connection with steel plates.

  5. Experimental investigation of axially loaded steel fiber reinforced high strength concrete-filled steel tube columns

    Institute of Scientific and Technical Information of China (English)

    卢亦焱; 李娜; 李杉; 梁鸿骏

    2015-01-01

    An experimental study on the compressive behavior of steel fiber reinforced concrete-filled steel tube columns is presented. Specimens were tested to investigate the effects of the concrete strength, the thickness of steel tube and the steel fiber volume fraction on the ultimate strength and the ductility. The experimental results indicate that the addition of steel fibers in concrete can significantly improve the ductility and the energy dissipation capacity of the concrete-filled steel tube columns and delay the local buckling of the steel tube, but has no obvious effect on the failure mode. It has also been found that the addition of steel fibers is a more effective method than using thicker steel tube in enhancing the ductility, and more advantageous in the case of higher strength concrete. An analytical model to estimate the load capacity is proposed for steel tube columns filled with both plain concrete and steel fiber reinforced concrete. The predicted results are in good agreement with the experimental ones obtained in this work and literatures.

  6. Evaluation of Steel Cleanliness in a Steel Deoxidized Using Al

    Science.gov (United States)

    Castro-Cedeño, Edgar-Ivan; Herrera-Trejo, Martín; Castro-Román, Manuel; Castro-Uresti, Fabián; López-Cornejo, Monserrat

    2016-06-01

    The effect of magnesium in the aluminum used as a deoxidizer on the cleanliness of steel was studied throughout a steelmaking route for the production of thin slabs. Two deoxidizers with different Mg contents were used. The Mg content of a "typical" deoxidizer was ~0.5 wt pct Mg, whereas that for an alternative deoxidizer was ~2 wt pct Mg. The inclusion population at different stages of the steelmaking process was characterized in terms of chemical composition, number, and size distribution. The inclusion modification path shows that the solid Al2O3 and Al2O3-MgO inclusions formed in the early stage of the steel ladle treatment are modified into Al2O3-MgO-CaO liquid and MgO-Al2O3-liquid inclusions. Although some slight differences were observed in the ladle furnace samples, the chemical composition of inclusions was similar in the samples taken at the mold of the continuous casting, regardless of the deoxidizer used. Gumbel, generalized extreme value (GEV), and generalized Pareto (GP) distributions were used for the description of the size distribution. The GEV and GP distributions resulted in proper distributions to describe the evolution of size distribution throughout the steelmaking process. Furthermore, no statistically significant differences between inclusion size distributions resulting from the use of either deoxidizer were found.

  7. [Initial stages of steel biocorrosion].

    Science.gov (United States)

    Zhigletsova, S K; Rodin, V B; Kobelev, V S; Aleksandrova, N V; Rasulova, G E; Kholodenko, V P

    2000-01-01

    Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8-10 h after inoculation. The number of viable cells were virtually unchanged within one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even only after incubation for 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in a significant damage to metals.

  8. Luders bands in RPV Steel

    OpenAIRE

    Johnson, D H

    2013-01-01

    The R6 procedure is used for the prevention and prediction of crack behaviour and other defects in the reactor pressure vessel(RPV). The RPV material is an upper-bainitic, low alloy steel structure, which deforms inhomogeneously when yielding. The current codes that are used to design and calculate the fracture, within an RPV, assume that the material yields continuously as the size of the L¨uders strain is less than 2%. However, the work of Wenman et al[1] has shown that the inclusion of a L...

  9. 嗜麦芽寡养单胞菌降解羽毛5L发酵罐工业小试过程研究%Study on Stenotrophomonas maltophilia DHHJ fermentation in5 L fermenter pilot plant

    Institute of Scientific and Technical Information of China (English)

    鲁丹; 曹张军; 周美华

    2009-01-01

    In order to industrialize the utilization of waste feather by microbiological method,the scale-upof fermentation from shaking flask to 5 L fermenter for Stenotrophomonas maltophilia DHHJ based on the study of fermentation in erlenmeyer flask was investigated.Further,this paper analyzed the fermentation process and optimized the technological parameters.The changes of material and energy in metabolic processes were conjectured,and the product formation of DHHJ batch fermentation kinetics was studied.Finally,under the circumstances of O.08 MPa pressure,2.5 L/min air flow.defined temperature of 40 ℃ and other controlled conditions,this yield was 1~2 fold higher in comparison with the shaking flask fermentation,fermentation period shortened by one day.And it provided the reliable basis for the use of the feather waste.%为了将微生物处理羽毛工艺产业化,在摇瓶发酵条件优化的基础上进行5 L发酵罐工业小试研究,确定了放大发酵条件并根据发酵条件记录对发酵过程进行分析,推测代谢过程中的物质及能量变化及产物形成的动力学模型.在通气气压为0.08 MPa,空气流量为2.5 L/min及恒温40℃的条件下,产物得率比摇瓶发酵提高了2~3倍,发酵周期缩短了l d.为羽毛废弃物的利用提供了可靠的依据.

  10. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A.; Kellner, A.W.; Harrison, J. [Metal Recovery Industries, Inc., Hamilton, ON (Canada)

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  11. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. (Argonne National Lab., IL (United States)); Morgan, W.A.; Kellner, A.W.; Harrison, J. (Metal Recovery Industries, Inc., Hamilton, ON (Canada))

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  12. Bauxite Based Bricks for Steel Ladle

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of bauxite based bricks for steel ladle linings.This standard is applicable to bauxite based bricks for working layer of steel ladle.

  13. Sprayformed Hot Work Steels for Rapid Tooling

    Institute of Scientific and Technical Information of China (English)

    Yunfeng Yang; Simo-Pekka Hannula

    2003-01-01

    The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts fo

  14. 49 CFR 192.55 - Steel pipe.

    Science.gov (United States)

    2010-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is qualified for use under this part if: (1) It was manufactured in accordance with a listed specification; (2... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  15. Purification of post-consumer steel crap

    NARCIS (Netherlands)

    Rem, P.C.; Van den Broeck, F.; Bakker, M.C.M.

    2012-01-01

    Post-consumer steel scrap is often hand picked for contaminants such as copper to meet specifications of steelmakers. If the hand sorting capacity exceeds 20 tons scrap/h the efficiency generally becomes problematic, leaving 50% of the copper contaminants in the steel product. In response, new techn

  16. Optimising steel hub location in Thailand

    Directory of Open Access Journals (Sweden)

    Sakaradhorn Boontaveeyuwat

    2012-11-01

    Full Text Available The optimal location of a steel hub in Thailand was analysed by applying aspecific research methodology designed to evaluate locations near the seaports. The growth of Thailand’s steel industry has become a centre of attention in the last decade, resulting in substantial efforts to form a distribution service centre to minimise the logistic costs associated with handling large steel flows in the future. The main analysis of the steel hublocation focused on areas situated near Laem Cha Bang, Map Ta Phut and Prachuab ports since these top three ports are considered important in terms of their steel throughput in Thailand. The transport costs associated with the shipment and inland transport together with port tariffs were calculated for the proposed scenarios of steel hub establishment andthese were compared with the existing situation without steel hub. The findings showed that a steel hub located near Laem Cha Bang port was the optimal option involving a saving of 9.4% on the total system costs incurred under the existing situation.

  17. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

    The PhD research is focused on the reinforcement of fatigue cracked orthotropic steel bridge decks (OBD) by adding a second steel plate to the existing deck. The main idea is to stiffen the existing deck plate, which will reduce the stresses at the fatigue sensitive details and extend the fatigue li

  18. Steel Sheet Pile Walls in Soft Soil

    NARCIS (Netherlands)

    Kort, D.A.

    2002-01-01

    For almost a century, steel sheet pile walls are applied worldwide as earth retaining structures for excavations and quay walls. Within the framework of the development of European structural codes for Civil Engineering works, the Eurocodes, Eurocode 3 Part 5 for design of steel sheet pile walls was

  19. Development of structural steels for nuclear application

    International Nuclear Information System (INIS)

    To established the bases of nuclear structural material technologies, this study was focused on the localization and improvement of nuclear structural steels, the production of material property data, and technology developments for integrity evaluation. The important test and analysis technologies for material integrity assessment were developed, and the materials properties of the pressure vessel steels were evaluated systematically on the basis of those technologies, they are microstructural characteristics, tensile and indentation deformation properties, impact properties, and static and dynamic fracture toughness, fatigue and corrosion fatigue etc. Irradiation tests in the research reactors were prepared or completed to obtain the mechanical properties of irradiated materials. The improvement of low alloy steel was also attempted through the comparative study on the manufacturing processes, computer assisted alloy and process design, and application of the inter critical heat treatment. On the other hand, type 304 stainless steels for reactor internals were developed and tested successfully. High strength type 316LN stainless steels for reactor internals were developed and the microstructural characteristics, corrosion resistance, mechanical properties at high temperatures, low cycle fatigue property etc. were tested and analyzed in the view point of the effect of nitrogen. Type 347 stainless steels with high corrosion resistance and toughness for pipings and tubes and low-activated Cr-Mn steels were also developed and their basic properties were evaluated. Finally, the martensitic stainless steels for turbine blade were developed and tests. (author). 242 refs., 100 tabs., 304 figs

  20. Behaviour of high strength steel moment joints

    NARCIS (Netherlands)

    Girão Coelho, A.M.; Bijlaard, F.S.K.

    2010-01-01

    The design of joints to European standard EN 1993 within the semi-continuous/partially restrained philosophy is restricted to steel grades up to S460. With the recent development of high performance steels, the need for these restrictions should be revisited. The semicontinuous joint modelling can b

  1. 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.

  2. A survey on decentralized steel industries

    Directory of Open Access Journals (Sweden)

    Mostafa Jafari

    2011-01-01

    Full Text Available During the past three decades there have been tremendous efforts on building steel factories on economic scales. The primary question is to find an economic scale for such plants which could also meet domestic demand. In this paper, we perform an empirical survey to find out whether building small steel factories are more suitable or setting up giant steel industries to meet regional demands. The results indicate that in many countries, building small steel plants based on the recent advances of technologies not only reduces the total cost of steel production but also it could significantly reduce the unnecessary transportation cost, providing cheaper labor, etc. This would lead to better competition which would increase the productivity.

  3. Corrosion of steels in sour gas environments

    International Nuclear Information System (INIS)

    This report presents a study on the effects of sour gas environments on steels. Emphasis is placed on alloys commonly used in the heavy water, sour gas and refining industries. In addition, 'high strength, low alloy' steels, known as 'oil country tubular goods', are included. Reference is made to the effects of hydrogen sulphide environments on austenitic steels and on certain specialty steels. Theories of hydrogen-related cracking mechanisms are outlined with emphasis placed on sulphide stress cracking and hydrogen induced cracking in carbon and low alloy steels. Methods of controlling sulphide stress cracking and hydrogen induced cracking are addressed separately. Case histories from the heavy water, refining, and sour gas industries are used to illustrate operating experience and failure mechanisms. Finally, recommendations, based largely on the author's industrial experience, are made with respect to quality assurance and inspection requirements for sour service components. Only published literature was surveyed. Abstracts were made of all references, reviewing the major sources in detail

  4. Design and Preparation of Steel Slag SMA

    Institute of Scientific and Technical Information of China (English)

    WU Shao-peng; YANG Wen-feng; XUE Yong-jie; LIN Zhen-hua

    2003-01-01

    On the basis of the characteristics of high rigidity and excellent friction resistance,a new kind of steel slag SMA (stone matrix asphalt) concrete was designed and prepared.The main processes include aggregate gradation,performance analysis of steel slag before and after aging,preparation methods and properties test of steel slag SMA.The experimental results indicate that the index of steel slag's activation is less than 1 percent,the dynamic stability is 5699 times/mm,and both the residual stability and ratio of frozen splitting strength are more than 80 percent;the friction factor and structure depth are 67.1% and 0.7mm respectively.These results show the steel slag SMA is superior to the common asphalt concrete and SMA that uses common aggregate.

  5. Hydrogen embrittlement in power plant steels

    Indian Academy of Sciences (India)

    R K Dayal; N Parvathavarthini

    2003-06-01

    In power plants, several major components such as steam generator tubes, boilers, steam/water pipe lines, water box of condensers and the other auxiliary components like bolts, nuts, screws fasteners and supporting assemblies are commonly fabricated from plain carbon steels, as well as low and high alloy steels. These components often fail catastrophically due to hydrogen embrittlement. A brief overview of our current understanding of the phenomenon of such hydrogen damage in steels is presented in this paper. Case histories of failures of steel components due to hydrogen embrittlement, which are reported in literature, are briefly discussed. A phenomenological assessment of overall process of hydrogen embrittlement and classification of the various damage modes are summarized. Influence of several physical and metallurgical variables on the susceptibility of steels to hydrogen embrittlement, mechanisms of hydrogen embrittlement and current approaches to combat this problem are also presented.

  6. Austenitic stainless steels with cryogenic resistance

    International Nuclear Information System (INIS)

    The most used austenitic stainless steels are alloyed with chromium and nickel and have a reduced carbon content, usually lower than 0.1 % what ensures corresponding properties for processing by plastic deformation at welding, corrosion resistance in aggressive environment and toughness at low temperatures. Steels of this kind alloyed with manganese are also used to reduce the nickel content. By alloying with manganese which is a gammageneous element one ensures the stability of austenites. Being cheaper these steels may be used extensively for components and equipment used in cryogenics field. The best results were obtained with steels of second group, AMnNi, in which the designed chemical composition was achieved, i.e. the partial replacement of nickel by manganese ensured the toughness at cryogenic temperatures. If these steels are supplementary alloyed, their strength properties may increase to the detriment of plasticity and toughness, although the cryogenic character is preserved

  7. Aerosol filtration with steel fiber filters

    Science.gov (United States)

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.

    1993-04-01

    An experimental study has been conducted of aerosol penetration through a new high efficiency steel fiber filter and filter media that was developed in cooperation with Pall Corporation. Previous studies have shown that sintered steel fiber media have significant improvements in higher filter efficiency and lower pressure drop than the previous steel filter technology based on sintered powder metal media. In the present study, measurements were made of the penetration of dioctyl sebacate (DOS) aerosols through flat sheet samples, pleated cartridge filters, and a 1000 cfm filter having 64 cartridges housed in a 2 x 2 x 1 ft. frame. The steel fiber media used in our study consists of 2 micron diameter stainless steel (316 L) fibers sintered together into sheets.

  8. Interaction between stainless steel and plutonium metal

    Energy Technology Data Exchange (ETDEWEB)

    Dunwoody, John T [Los Alamos National Laboratory; Mason, Richard E [Los Alamos National Laboratory; Freibert, Franz J [Los Alamos National Laboratory; Willson, Stephen P [Los Alamos National Laboratory; Veirs, Douglas K [Los Alamos National Laboratory; Worl, Laura A [Los Alamos National Laboratory; Archuleta, Alonso [Los Alamos National Laboratory; Conger, Donald J [Los Alamos National Laboratory

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  9. An understanding of HSLA-65 plate steels

    Science.gov (United States)

    Sampath, K.

    2006-02-01

    HSLA-65 plate steels can be produced using one of five plate manufacturing techniques: normalizing, controlled rolling (CR), controlled rolling followed by accelerated cooling (CR-AC), direct quenching and tempering (DQT), or conventional quenching and tempering (Q&T). The HSLA-65 steels are characterized by low carbon content and low alloy content, and they exhibit a low carbon equivalent that allows improved plate weldability. These characteristics in turn (a) provide the steel plate with a refined microstructure that ensures high strength and toughness; (b) eliminate or substantially reduce the need for preheating during welding; (c) resist susceptibility to hydrogen-assisted cracking (HAC) in the weld heat affected zone (HAZ) when fusion (arc) welded using low heat-input conditions; and (d) depending on section thickness, facilitate high heat-input welding (about 2 kJ/mm) without significant loss of strength or toughness in the HAZ. However, application of this plate manufacturing process and of these controls produces significant differences in the metallurgical structure and range of mechanical properties of the HSLA-65 plate steels both among themselves and versus conventional higher strength steel (HSS) plates. For example, among the HSLA-65 plate steels, those produced by Q&T exhibit minimal variability in mechanical properties, especially in thicker plates. Besides variability in mechanical properties depending on plate thickness, the CR and CR-AC plate steels exhibit a relatively higher yield strength to ultimate tensile strength (YS/UTS) ratio than do DQT and Q&T steels. Such differences in processing and properties of HSLA-65 plate steels could potentially affect the selection and control of various secondary fabrication practices, including arc welding. Consequently, fabricators must exercise extreme caution when transferring allowable limits of certified secondary fabrication practices from one type of HSLA-65 plate steel to another, even for the

  10. Graphitization in CK 45 Steel

    Institute of Scientific and Technical Information of China (English)

    A.R.Kiani-Rashid

    2009-01-01

    The purpose of this study was to determine the influence of heat treatment cycle on graphite phase formation on CK 45 steel. The presence of well distributed graphite in the matrix is responsible for the good mechanical and thermal properties of this kind of alloy. Such properties include excellent wear resistance, higher resistance to thermal shock, and higher resistance to oxidation at high temperature. A number of specimens were made up of appropriate design to provide the experimental materials. The transformation phase to a free carbon microstructure during graphitization under different conditions was then examined for the most successful experimental steels. Austenitising temperature of 920℃ ahd the following isothermal heat treatment of 750℃ at different holding times were used. Microstructures were examined by OM (optical microscopy) and SEM (scanning electron microscopy). Furthermore, it was found that isothermal transformation at 750℃for different soaking times produced a typical microstructure. Also, the amount of graphite increased with increasing isothermal heat treatment time. Heat treatment leading to supersaturation of iron with carbon was described and some of the consequences of the supersaturation were presented. Finally, the formation of the thermodynamically stable state of the graphite taken from the supersaturated solid solution was discussed.

  11. Atmospheric corrosion of mild steel

    Directory of Open Access Journals (Sweden)

    Morcillo, M.

    2011-10-01

    Full Text Available The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a the morphology of steel corrosion products and corrosion product layers; and b long-term atmospheric corrosion ( > 10 years.

    La corrosión atmosférica del acero suave es un tema de gran amplitud que ha sido tratado por muchos autores en numerosas regiones del mundo. Este artículo de compilación incorpora publicaciones relevantes sobre esta temática, en particular sobre la naturaleza de los productos de corrosión atmosférica, mecanismos y cinética de los procesos de corrosión atmosférica, prestando una atención especial a dos aspectos sobre los que la información publicada ha sido menos abundante: a morfología de los productos de corrosión del acero y capas de productos de corrosión, y b corrosión atmosférica a larga duración (> 10 años.

  12. Analysis on Hydraulic Blasting Fracture Separation of Heavy Wall Thickness Steel Pipe Used in Subsea Pipeline%海底管线用大壁厚钢管水压爆破断口分离现象分析

    Institute of Scientific and Technical Information of China (English)

    赵金兰; 李记科; 李金凤; 杨东升

    2011-01-01

    对某海底管线用X70级φ765.2 mm×31.8 mm直缝埋弧焊管进行水压爆破试验时,钢管爆破失效后出现了较严重的断口分离现象.爆管断口试样宏观形貌显示,断口上有3种形貌特征:即壁厚中心分离较深、两侧分离较浅和韧性剪切面.通过金相分析、能谱分析、扫描电镜等方法,对断口分离现象进行了分析研究.研究结果表明:MA带状偏析组织是造成此水压爆破断口分离现象的主要原因.%Hydraulic blasting test was conducted on X70Φ765.2 mm×31.8 mm SAWL pipe which was used in subsea pipeline,the serious fracture separation phenomenon occurred after steel pipe blasting failure. The fracture macroscopic appearance showed that 3 kinds of appearance feature exist,namely the deeper separation in the center of wall thickness,the shallower break at both sides of wall thickness and toughness shear area. The fracture separation phenomenon was analyzed and studied by metallographic analysis,energy spectrum analysis,scanning electron microscope and other methods;the results indicated that the MA banded separation structure is the main reason caused hydraulic blasting fracture separation.

  13. Automated Steel Cleanliness Analysis Tool (ASCAT)

    International Nuclear Information System (INIS)

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel cleanliness; slab, billet

  14. Automated Steel Cleanliness Analysis Tool (ASCAT)

    Energy Technology Data Exchange (ETDEWEB)

    Gary Casuccio (RJ Lee Group); Michael Potter (RJ Lee Group); Fred Schwerer (RJ Lee Group); Dr. Richard J. Fruehan (Carnegie Mellon University); Dr. Scott Story (US Steel)

    2005-12-30

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel

  15. 29 CFR 1926.757 - Open web steel joists.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  16. A Survey of Mathematical Programming Applications in Integrated Steel Plants

    OpenAIRE

    Goutam Dutta; Robert Fourer

    2001-01-01

    Mathematical programming techniques were used in the steel industry as early as 1958, and many applications of optimization in steel production have been reported since then. In this survey, we summarize published applications in the largest steel plants by type, including national steel planning, product-mix optimization, blending, scheduling, set covering, and cutting stock.

  17. Duplex stainless steels for osteosynthesis devices.

    Science.gov (United States)

    Cigada, A; Rondelli, G; Vicentini, B; Giacomazzi, M; Roos, A

    1989-09-01

    The austenitic stainless steels used today for the manufacture of osteosynthesis devices are sensitive to crevice corrosion. In this study the corrosion properties of some duplex stainless steels were evaluated and compared to traditional austenitic stainless steels. According to our results the following ranking was established: 23Cr-4Ni less than AISI 316L less than ASTM F138 less than 22Cr-5Ni-3Mo less than 27Cr-31Ni-3.5Mo less than 25Cr-7Ni-4Mo-N. In particular the results showed that the high-performance 25Cr-7Ni-4Mo-N duplex stainless steel, with high molybdenum and nitrogen contents, can be considered not susceptible to crevice corrosion in the human body. The duplex stainless steels have also better mechanical properties at the same degree of cold working compared with austenitic stainless steels. Hence the 25Cr-7Ni-4Mo-N duplex stainless steel can be considered a convenient substitute of ASTM F138 for orthopedic and osteosynthesis devices. PMID:2777835

  18. Preparation of precursor for stainless steel foam

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiang-yang; LI Shan-ni; LI Jie; LIU Ye-xiang

    2008-01-01

    The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed, and the,performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated. The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge, and it is also an effective method for increasing the slurry loading in precursor; the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor, when they are kept in 9%-13% and 52%-75%, respectively, the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles; the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength, apparent density and open porosity of stainless steel foam; when the stainless steel powder with particle size of 44 tan and slurry loading of 0.5 g/cm3 in precursor are used, a stainless steel foam can be obtained, which has open porosity of 81.2%, bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.

  19. The heat treatment of Fermanal cast steel

    Directory of Open Access Journals (Sweden)

    F. Binczyk

    2007-12-01

    Full Text Available The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite is the content of aluminium. The matrix totally austenitic is present in cast steel containing from 0,8 to 0,9% C, from 22 to 24% Mn, and from 4,5 to 5,5% Al. The magnetic properties examined on samples of the Fermanal cast steel were determined by spectroscopy of the Mössbauer effect with isotope 57Fe. The magnetic properties represented by a mean value of the hyperfine magnetic field Bhf and relative magnetic permeability were determined. It has been stated that the level of magnetic properties of the Fermanal cast steel depends on the content of ferrite. The effect of the parameters of solutioning and ageing on the cast steel microstructure and hardness after modification with additions of B, Ti and Nb was investigated.

  20. Hydrogen degradation of high-strength steels

    Directory of Open Access Journals (Sweden)

    J. Ćwiek

    2009-12-01

    Full Text Available Purpose: of this paper is to evaluate susceptibility of high-strength steels and welded joints to hydrogen degradation and to establish applicable mechanism of their hydrogen embrittlement and hydrogen delayed cracking.Design/methodology/approach: High-strength quenched and tempered steel grade S690Q and its welded joints have been used. Structural low-alloy steel 34CrAlNi7-10 with various plasma nitrided layers was evaluated. Susceptibility to hydrogen embrittlement of steel, welded joints, and nitrided layers was evaluated using monotonically increasing load. Slow strain rate test (SSRT was carried out in hydrogen generating environments. Susceptibility to hydrogen delayed cracking was evaluated under constant load in artificial sea water. Fractographic examinations with the use of a scanning electron microscope (SEM were performed to establish suitable mechanism of hydrogen-enhanced cracking.Findings: Tested high-strength steel and its welded joints are susceptible to hydrogen embrittlement when evaluated with the use of SSRT. The loss of plasticity is higher for welded joints then for the base metal. Tested steel and welded joints reveal high resistance to hydrogen degradation under constant load. Plasma nitrided layers are effective barriers for hydrogen entry into structural steel.Research limitations/implications: There has been no possibility to perform direct observations of exact mechanism of hydrogen-assisted cracking so far. Further research should be taken to reveal the exact mechanism of increased plasticity of a nitrided layer with absorbed hydrogen.Practical implications: Tested steel and its welded joints could be safely utilized within elastic range of stress in hydrogen generating environments, and constructions under cathodic protection provided that overprotection does not take place.Originality/value: Hydrogen-Enhanced Localized Plasticity (HELP model is a more applicable mechanism of hydrogen degradation than the others

  1. Recycling galvanized steel: Operating experience and benefits

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A. [Metal Recovery Industries, Inc., East Chicago, IN (United States)

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  2. 76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...

    Science.gov (United States)

    2011-03-21

    ...), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels with...) steels, and the substrate for motor lamination steels. IF steels are recognized as low carbon steels with... FR 74682 (December 1, 2010). On January 3, 2011, we received from United States Steel Corporation,...

  3. Resistance Spot Welding of dissimilar Steels

    OpenAIRE

    Ladislav Kolařík; Miroslav Sahul; Marie Kolaříková; Martin Sahul; Milan Turňa; Michal Felix

    2012-01-01

    This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA). Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to e...

  4. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  5. Dynamic characteristics of automotive steel sheets

    Directory of Open Access Journals (Sweden)

    M. Mihaliková

    2016-10-01

    Full Text Available The aim of this experimental research was to perform an analysis of deformation characteristics on two different types of steel: IF steel, and micro-alloyed steel were used automotive industry. For that purpose changes of properties of these materials were carried out by static 10-3 · s-1 and dynamic 103 · s-1 strain rate assess its plastic properties. Vickers micro hardness test was carried out by the static and dynamic loading condition and describes different hardness distribution. The higher strain hardening of materials was obtained too that was confirmed by distribution of dislocations.

  6. Radiation-induced sensitisation of stainless steels

    International Nuclear Information System (INIS)

    The book contains the proceedings of a symposium on radiation-induced sensitization of stainless steels, which took place at Berkeley, United Kingdom, 1986. The purpose of the symposium was to examine the mechanism leading to inter-granular corrosion of 20%Cr/25% Ni/Nb stainless steel cladding of AGR fuel following irradiation. Nine papers are presented, of which three are theoretical, two papers are based upon corrosion studies of 20%Cr/25%Ni/Nb steel, and the remaining are concerned with compositional redistribution and its measurement. (U.K.)

  7. Recycle of radiologically contaminated austenitic stainless steels

    International Nuclear Information System (INIS)

    The United States Department of Energy owns large quantities of radiologically contaminated austenitic stainless steel which could by recycled for reuse if appropriate release standards were in place. Unfortunately, current policy places the formulation of a release standard for USA industry years, if not decades, away. The Westinghouse Savannah River Company, Idaho National Engineering Laboratory and various university and industrial partners are participating in initiative to recycle previously contaminated austenitic stainless steels into containers for the storage and disposal of radioactive wastes. This paper describes laboratory scale experiments which demonstrated the decontamination and remelt of stainless steel which had been contaminated with radionuclides

  8. Titanium Content Control for Bearing Steel

    Institute of Scientific and Technical Information of China (English)

    WU Wei; LIU Yue; LIU Liu; XUE Zheng-liang

    2008-01-01

    On the basis of the thermodynamic analysis and fundamental study in the laboratory,the equilibrium of the Ti-Al-O system was investigated.The results showed that the equilibrium titanium content in the steel increased with the increase in the soluble aluminum content in the steel and the TiO2 content in the slag.Although the slag basicity decreased and Al2O3 content in the slag increased,the titanium content increased.Based on these results,the BOF smelting process of low titanium bearing steel was put forward.

  9. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  10. Tribocorrosion wear of austenitic and martensitic steels

    Directory of Open Access Journals (Sweden)

    G. Rozing

    2016-07-01

    Full Text Available This paper explores the impact of tribocorrosion wear caused by an aggressive acidic media. Tests were conducted on samples made of stainless steel AISI 316L, 304L and 440C. Austenitic steels were tested in their nitrided state and martensitic in quenched and tempered and then induction hardened state. Electrochemical corrosion resistance testing and analysis of the microstructure and hardness in the cross section was carried out on samples of selected steels. To test the possibility of applying surface modification of selected materials in conditions of use, tests were conducted on samples/parts in a worm press for final pressing.

  11. The optical metallography of some maraging steels

    International Nuclear Information System (INIS)

    The structural features of maraging steels, including those that impose limitations on strength and toughness, are briefly reviewed. Phase relationships in the iron-nickel matrix system are introduced which, in conjunction with alloy composition and heat treatment, allow the interpretation of microstructure. Details are presented of methods for revealing the microstructure of maraging steels; the prior austenite grain size following a variety of heat treatments is of special interest since excessive grain size can lead to poor ductility. These methods are illustrated with micrographs of the microstructures of MAR 350 and MAR 400 steels in the cast, solution-treated, aged and cold-worked states

  12. The stretch zone of automotive steel sheets

    Indian Academy of Sciences (India)

    Ľ Ambriško; L Pešek

    2014-04-01

    The paper deals with an experimental determination of the stretch zone dimensions in the notch tip in thin steel sheets. The stretch zone dimensions depend on steel grade, on the rolling direction as well as on the loading rate. Stretch zones were observed and measured on three steel grades. Fracture area and stretch zones were analysed by SEM. Stable crack growth was monitored by videoextensometry techniques on CT (Compact Tension) specimens. Specimens were loaded under two loading rates by eccentric tension, whereby the deformation in the notch surrounding area was recorded using a non-contact measurement–videoextensometry technique. Linear relation between the stretch zone dimensions was determined.

  13. Niobium in steels and alloys

    International Nuclear Information System (INIS)

    Data are presented on the reserves and processing of niobium raw materials followed by brief review of the current status and long-range trends in the commercial usage of niobium and its compounds. A survey is made of the physical properties of niobium and its chemical reactions with elements of direct concern in the manufacture of ferroalloys, quality steels and other products. Niobium minerals and ores, along with common ore processing practices are described briefly. Attention is paid to Brazilian niobium ores, and to the Araxa deposit specifically. Some emphasis has been given to methods of processing lean niobium ores not easily amenable to simple concentration. A systematic review is presented of the techniques used in the production of niobium ferroalloys. (E.G.)

  14. CHARACTERIZATION OF NEW TOOL STEEL FOR ALUMINUM EXTRUSION DIES

    OpenAIRE

    José Britti Bacalhau; Fernanda Moreno Rodrigues; Rafael Agnelli Mesquita

    2014-01-01

    Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition ...

  15. Experience with ferrosilicoaluminum alloy during deoxidation of steel

    OpenAIRE

    Mekhtiyev, A.; Akhmetov, A.; V. Yudakova; Bulatbayev, F.

    2016-01-01

    The article describes the process of deoxidation quiet and low-alloyed steel alloy ferrosilicoaluminum complex in comparison the existing, and with steel deoxidation technology with conventional alloys - ferrosilicon and secondary aluminum. A comparative analysis of quality steel, non-metallic inclusions metallographic studies and studies of the mechanical properties of the resulting steel was done. On a large array of experimental steel proved cost-effectiveness and feasibility of ferrosilic...

  16. Do steel prices move together? : a cointegration test

    OpenAIRE

    Qian, Ying

    1990-01-01

    Lack of international comparability in crude steel prices presents a problem in constructing an econometric model of the global steel market. The commonly used measures of crude steel prices are the weighted average of the prices of steel products and the index of the weighted average of prices based on a certain year. But in the context of constructing an econometric model of the global steel market, these measures are not comparable internationally. If the various product prices are cointeg...

  17. Project B: Improved Liquid Steel Feed For Slab Casters

    Energy Technology Data Exchange (ETDEWEB)

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  18. Review on research and application of stainless steel reinforced concrete

    OpenAIRE

    Gu Li; Meng Xian Hong

    2016-01-01

    For ordinary reinforced under corrosion environment corrosion problems and analysis the main factors affecting ordinary steel corrosion, proposed stainless steel bar rust and corrosion resistance advantages, introduce the related properties of the stainless steel reinforced, combined with the research status of domestic and international stainless steel bar, put forward the research and engineering application of stainless steel rebar for the related problems and direction, the prospects and ...

  19. Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel

    Energy Technology Data Exchange (ETDEWEB)

    Jafarzadegan, M. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Feng, A.H. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Abdollah-zadeh, A., E-mail: zadeh@modares.ac.ir [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Saeid, T. [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of); Shen, J. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Assadi, H. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)

    2012-12-15

    In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

  20. THE STRUCTURAL ANALYSIS OF STEEL SILOS WITH CYLINDRICAL-WALL BEARING AND PROFILE-STEEL BEARING

    OpenAIRE

    Zhengjun Tang; Daibiao Zhou; Chenwei Peng; Wenping Wu

    2015-01-01

    The silos are widely used in bulk material in many fields such as agriculture, mining, chemical, electric power storage, etc. Thin metal cylindrical silo shells are vulnerable to buckling failure caused by the compressive wall friction force. In this paper, the structural analysis of two types of steel silo with cylindrical-wall bearing and profile-steel bearing is implemented by Abaqus finite element analysis. The results indicate that under the same loading conditions, steel silos with prof...

  1. FEM Simulation of Bending Formability for Laminate Steel/Resin/Steel Lightweight Composite Sheet

    Institute of Scientific and Technical Information of China (English)

    Guancheng Ll; Yonglin KANG

    2003-01-01

    The ANSYS simulation software was used to analyze the bending formability of laminate steel/resin/steel lightweight composite sheet. The skin steel at external side produces relative slipping-off change during the bending due to its composite structure. The internal stress strain states, materials effect tools parameters and intermediate layer resin of lightweight sheet on slipping-off change were analyzed. The spring back and shear stress state after bending have also been discussed.

  2. Hydrogen gas embrittlement of stainless steels mainly austenitic steels. Volumes 1 and 2

    International Nuclear Information System (INIS)

    Steel behavior in regard to hydrogen is examined especially austenitic steels. Gamma steels are studied particularly the series 300 with various stabilities and gamma steels with improved elasticity limit for intermetallic phase precipitation and nitrogen additions. A two-phase structure γ + α' is also studied. All the samples are tested for mechanical behavior in gaseous hydrogen. Influence of metallurgical effects and of testing conditions on hydrogen embrittlement are evidenced. Microstructure resulting from mechanical or heat treatments, dislocation motion during plastic deformation and influence of deformation rate are studied in detail

  3. Numerical Analysis of Composite Steel Concrete Structural Shear Walls with Steel Encased Profiles

    Directory of Open Access Journals (Sweden)

    Daniel Dan

    2009-01-01

    Full Text Available The use of common reinforced concrete shear walls in high rise buildings is sometimes limited because of the large amount of reinforcement localized at the end of the element. A good alternative in avoiding this disadvantage is to use composite steel concrete structural shear walls with steel encased profiles. This solution used for high rise buildings, offers to designers lateral stiffness, shear capacity and high bending resisting moment of structural walls. The encasement of the steel shapes in concrete is applied also for the following purposes: flexural stiffening and strengthening of compression elements; fire protection; potentially easier repairs after moderate damage; economy with respect both to material and construction. Until now in the national and international literature poor information about nonlinear behaviour of composite steel concrete structural shear walls with steel encased profiles is available. A theoretical and experimental program related to the behaviour of steel concrete structural shear walls with steel encased profiles is developed at “Politehnica” University of Timişoara. The program refers to six different elements, which differ by the shape of the steel encased profile and also by the arrangement of steel shapes on the cross section of the element. In order to calibrate the elements for experimental study some numerical analysis were made. The paper presents the results of numerical analysis with details of stress distribution, crack distribution, structural stiffness at various loads, and load bearing capacity of the elements.

  4. Lightweight Steel Solutions for Automotive Industry

    Science.gov (United States)

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-01

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  5. Advances in the heat treatment of steels

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.W. Jr.; Kim, J.I.; Syn, C.K.

    1978-06-01

    A number of important recent advances in the processing of steels have resulted from the sophisticated uses of heat treatment to tailor the microstructure of the steels so that desirable properties are established. These new heat treatments often involve the tempering or annealing of the steel to accompish a partial or complete reversion from martensite to austenite. The influence of these reversion heat treatments on the product microstructure and its properties may be systematically discussed in terms of the heat treating temperature in relation to the phase diagram. From this perspective, four characteristic heat treatments are defined: (1) normal tempering, (2) inter-critical tempering, (3) intercritical annealing, and (4) austenite reversion. The reactions occurring during each of these treatments are described and the nature and properties of typical product microstructures discussed, with specific reference to new commercial or laboratory steels having useful and exceptional properties.

  6. The World's Largest Steel Casting Poured Successfully

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The world's largest steel casting -- the upper beam (or the top head) for free forging oil hydraulic press with a 18,000-ton force capacity, was poured successfully by CITIC Heavy Machinery Co., Ltd. (CITICHM) on May 22, 2008. This head piece is 11.95 meters long, 3.8 meters wide, 4.59 meters high and about 520 tons in gross weight. Pouring is the most important and critical step during its manufacturing process. The production of this huge casting requires about 830 tons of refined molten steel from 10 smelting furnaces and pouring with six ladles into the mold cavity at one time, which made it currently the world's largest steel casting poured and the most one-time molten steel organized.

  7. Fatigue in Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    1999-01-01

    Fatigue damage accumulation in steel structures under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series have been carried through on various...... types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel with a yield stress of ~ 360-410 MPa or high-strength steel with a yield stress of ~ 810-1010 MPa. The fatigue tests and the fracture mechanics analyses...... test results. Both the fracture mechanics analysis and the fatigue test results indicate that Miner's rule, which is normally used in the design against fatigue in steel structures, may give results, which are unconservative, and that the validity of the results obtained from Miner's rule will depend...

  8. Clean Cast Steel Technology, Phase IV

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates

    2003-02-24

    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  9. Overview of Steel Slag Application and Utilization

    Directory of Open Access Journals (Sweden)

    Lim J.W.

    2016-01-01

    Full Text Available Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD, Scanned Electron Microscopy (SEM and Inductive Coupled Plasma (ICP-OES are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

  10. Stainless Steel to Titanium Bimetallic Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Kaluzny, J. A. [Fermilab; Grimm, C. [Fermilab; Passarelli, D. [Fermilab

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  11. Effect of ultrasonic oscillations on steel rolling

    International Nuclear Information System (INIS)

    The effect of radial ultrasonic oscillations on rolling has been studied. Plates and pipes made of the St3 and 08Kh18N10T steel were rolled at 20 and at 1200 deg C. Ultrasonic waves proved to reduce pressure on the rollers by 9-14%, this eventually leading to higher efficiency of rolling. Hot rolling involving ultrasonic treatment decreased the ultrimate strength and yield point of both steels by 5-10% and increased relative elongation on account of uniform contraction. Cold ultrasound-involving rolling decreased the ultimate strength and the yield point of the St3 steel, hardly affecting those of the 08Kh18N10T steel

  12. Corrosion behavior of sensitized duplex stainless steel.

    Science.gov (United States)

    Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

    1998-01-01

    The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures. PMID:9713683

  13. Bitter Operation in Global Steel Industry

    Institute of Scientific and Technical Information of China (English)

    Wang Sujuan

    2009-01-01

    @@ Shrinking international demand Global economy started to decline from the second half of 2008. Along with weak real estate market and dull automobile sales, steel industry fell into stagnant operation after six-year-straight rapid development.

  14. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz;

    1999-01-01

    . The effect of induction surface hardening on the properties of the coating-substrate-systems is mainly characterized using investigations of microstructure and chemical composition as well as measurements of hardness and residual stresses in dependence on the distance from the surface. Furthermore......The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD......-process is the high deposition temperature, consequently the properties of steel substrates are negatively influenced. Therefore, a subsequent heat treatment of the coated steels is necessary to restore the properties of steels ready for operation. Induction surface hardening is used as a method of heat treatment...

  15. Advances in the heat treatment of steels

    International Nuclear Information System (INIS)

    A number of important recent advances in the processing of steels have resulted from the sophisticated uses of heat treatment to tailor the microstructure of the steels so that desirable properties are established. These new heat treatments often involve the tempering or annealing of the steel to accompish a partial or complete reversion from martensite to austenite. The influence of these reversion heat treatments on the product microstructure and its properties may be systematically discussed in terms of the heat treating temperature in relation to the phase diagram. From this perspective, four characteristic heat treatments are defined: (1) normal tempering, (2) inter-critical tempering, (3) intercritical annealing, and (4) austenite reversion. The reactions occurring during each of these treatments are described and the nature and properties of typical product microstructures discussed, with specific reference to new commercial or laboratory steels having useful and exceptional properties

  16. Hydrogen compatibility handbook for stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  17. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests

  18. Localized Corrosion of Chromium Coated Steel

    NARCIS (Netherlands)

    Zhang, X.; Beentjes, P.; Mol, A.; Terryn, H.

    2006-01-01

    In this paper, we report on the studies of the local corrosion behaviour of chromium-coated ultra low carbon steel in NaCl solution using polarization, electrochemical impedance spectroscopy (EIS) and SVET.

  19. Discussion on Tensile Test Elongation in API SPEC 5L(45th Version)%对API SPEC 5L(45版)中有关拉伸试验伸长率的讨论

    Institute of Scientific and Technical Information of China (English)

    李记科; 杨红兵

    2015-01-01

    In this article, after discussion on tensile test elongation in API SPEC 5L (45th version) 10.2.4 clause, it considered its standard requirements are unreasonable. It suggests to adopt the requirements in the 6.2.1 clause of API SPEC 5L (43rd version):when elongation is recorded or reported, the record or report shall show the nominal width of the test specimen when strip specimens are used and the diameter and gauge length when round bar specimens are used, or shall state when full section specimens are used. Or the standard requirements are modified to:The percentage elongation of 4 times proportion test pieces (gauge length is 4 times the diameter of the round test pieces, L0=4D0, k= L0≈4.5 ) after fracture shall be reported.√S0 For test pieces with reference to a gauge length of 50 mm(2 in), the measured elongation after fracture shall be converted to a percentage elongation of 4 times proportion test pieces in accordance with ISO 2566-1 or ASTM A370.%对API SPEC 5L (45版)10.2.4试验方法中有关拉伸试验伸长率的内容进行了讨论,认为其标准要求不合理。建议采用API SPEC 5L (43版)6.2.1拉伸性能条款中的要求:“当需记录或报告伸长率时,如采用板状试样,记录或报告中应注明试样的公称宽度;如采用圆棒试样,应注明直径和标距长度;如采用全断面试样亦应予以注明”。或者修改为:“应报告4倍比例试样(标距长度为4倍直径的棒状试样, L0=4D0, k= L0√S0≈4.5)的断后伸长率。对于采用50 mm(2 in)定标距试样,应按照ISO 2566-1或ASTM A370,将断裂后测得的伸长率转换为4倍比例试样的断后伸长率。”

  20. Modification of Slenderness Coefficient of Angle Steels

    Institute of Scientific and Technical Information of China (English)

    刘红燕; 李志业

    2004-01-01

    To provide information for amendment to Technical Specifications for Power Transmission Towers (SDGJ94-90), the critical loads of typical compressed angle steels was calculated. The correlation of buckling loads and slenderness of compressed angle steels was obtained with regression. A new slenderness coefficient equation was proposed based on the result of the correlation. A practical measure to ensure good result in nonlinear solution using Arch-length method is put forward.

  1. Hot ductility of continuously cast structural steels

    Energy Technology Data Exchange (ETDEWEB)

    Pytel, S.M. [Materials Science and Technology Institute, Cracow University of Technology, Cracow (Poland)

    1995-12-31

    The objective of this investigation was to explain the hot ductility of the structural steels characterized by different amount of carbon and morphology of sulfides. Two different rolling processes were simulated under computer controlled, high temperature deformation MTS system. Results of this study show that morphology of sulfides as well as temperature and amount of deformation are responsible for level of hot ductility of the steel tested. (author). 7 refs, 5 refs, 4 tabs.

  2. Rapid solidification of candidate ferritic steels

    International Nuclear Information System (INIS)

    HT-9 and 9Cr-1Mo steels were rapidly solidified by the liquid dynamic compaction process and 2-1/4Cr-1Mo steel was prepared by the ultrasonic gas atomization process. The consolidation was performed in the ferritic temperature range in order to minimize segregation. These alloys will be tested at ORNL using 1/3 CVN test specimens and the results will be compared with those for conventially processed alloys

  3. Response of steel structures to fire actions

    OpenAIRE

    Čermelj, Blaž

    2008-01-01

    The degree represents procedure of fire analysis of steel buildings with advanced methods regarding Eurocode standards. Beside fire analyse of steel construction analyse of composite plate is also introduced. Introduction consists of basiscs, procedures and idea of fire analysis of buildings. Because entire work is based on advanced fire analysis, advanced fire models and advanced calculation models were used. Fire analysis of buildings with advanced methods describes behaviour of structure i...

  4. A Duplex Stainless Steel for Chloride Environments

    Science.gov (United States)

    Sridhar, N.; Kolts, J.; Flasche, L. H.

    1985-03-01

    This paper examines the effects of microstructural changes on the corrosion, stress corrosion cracking and corrosion fatigue resistance of a duplex stainless steel to chloride environments. The microstructural changes can be precipitation of phases such as sigma and carbides, or changes in the distribution of austenite and ferrite. The former can be important in hot forming operations while the latter is important in welding. The methods of minimizing these deleterious effects can sometimes be different from those used for austenitic stainless steel.

  5. Thermal treatment of dissimilar steels' welded joints

    Science.gov (United States)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  6. Deformation and Recrystallisation in Low Carbon Steels

    OpenAIRE

    Almojil, Marwan

    2010-01-01

    The annealing behaviour, including studies of recrystallisation kinetics anddevelopment of crystallographic texture, of two low carbon steels after different coldrolling reductions have been investigated using Optical Microscopy (OM), ElectronBack-Scatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM).The primary recrystallisation behaviour of 20, 50, 70 and 90% cold rolled InterstitialFree (IF) and High Strength Low Alloy (HSLA) steels was studied. The HSLA wasinitially proces...

  7. Stainless chromium-nickel steels. Chapter I

    International Nuclear Information System (INIS)

    The chemical composition is tabulated of 90 chromium-nickel stainless steels and alloys given in volume %. The values are also given of the corrosion resistance of the steels and alloys. The tables show data on the surface condition or the methods of material working, types and chemical composition of the medium where corrosion resistance tests were carried out, temperature, pressure, time of tests, corrosion rates, corrosion types, and literature references. A total of 35 references is given. (J.B.)

  8. Complex steel saturation with niobium and vanadium

    International Nuclear Information System (INIS)

    Studies on determining possibility of niobium and vanadium alloying with carbides were conducted. Possibility of simultaneous saturation of carbon steels with niobium and vanadium was established. Diffusion layers coated on surfaces of 45, U8A and U10A steels under different conditions. It is shown that increase of coating density by means of alloying favours the increase of its corrosion resistance in water and aqueous solutions of salt and soda 2 times, wear resistance -1.6-5 times

  9. Laser welding of advanced high strength steels

    OpenAIRE

    Ahmed, Essam Ahmed Ali

    2011-01-01

    This research work focuses on characterization of CO2 laser beam welding (LBW) of dual phase (DP) and transformation induced plasticity (TRIP) steel sheets based on experimental, numerical simulation and statistical modeling approaches. The experimental work aimed to investigate the welding induced-microstructures, hardness, tensile properties and formability limit of laser welding butt joints of DP/DP, TRIP/TRIP and DP/TRIP steel sheets under different welding speeds. The effects of shieldin...

  10. Hybrid Laser-Arc Welding Tanks Steels

    Science.gov (United States)

    Turichin, G.; Tsibulskiy, I.; Kuznetsov, M.; Akhmetov, A.; Klimova-Korsmik, O.

    2016-04-01

    The results investigate hybrid laser-arc welding of high strength steels using design responsible metallic construction and the highest strength body of vehicles. Welds from modern high strength steels grade Hardox 400, Hardox 450, Armox 600T and AB were created. High power fiber laser LS-15 with output 15 kW and arc rectifier VDU - 1500 DC were used in the experiment. Results of the metallographic research and mechanical tests are presented.

  11. Studies of stainless steel exposed to sandblasting

    OpenAIRE

    Horodek Paweł; Eseev Marat K.; Kobets Andrey G.

    2015-01-01

    The influence of sandblasting on surface and subsurface of stainless steel is investigated using variable energy positron beam (VEP), positron annihilation spectroscopy (PAS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Samples of stainless steel were blasted using 110 μm particles of Al2O3 under different pressure and time duration. In the case of sandblasting for 90 s, the reduction of positron diffusion length depending on the applied pressure was observed. Sandb...

  12. Marine atmospheric corrosion of carbon steels

    OpenAIRE

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

    2015-01-01

    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...

  13. Mix design of steel fiber reinforced concrete

    OpenAIRE

    Moreno, E.; Fernández Cánovas, M.

    1997-01-01

    Mix design of steel fiber reinforced concrete (SFRC) is concerned with achieving a workability, homogeneity, durability and strength suitable for its use. Variables defining any mix design of SFRC are commented below, as well as their influence on some properties of fresh and hardened SFRC. A special attention is paid to concrete, since it's the main use of steel fibers in Spain now, followed by paving construction.

    El objetivo de una correcta dosificación de horm...

  14. Fracture toughness properties of duplex stainless steels

    OpenAIRE

    Sieurin, Henrik

    2006-01-01

    Good toughness properties in base and weld material enable the use of duplex stainless steels (DSS) in critical applications. DSS offer high strength compared to common austenitic stainless steels. The high strength can be utilized to reduce the wall thickness and accordingly accomplish reduction of cost, welding time and transportation weight, contributing to ecological and energy savings. Although DSS have been used successfully in many applications the last decades, the full utilisation in...

  15. Advanced Ultra high Strength Bainitic Steels

    OpenAIRE

    García Caballero, Francisca; García Mateo, Carlos; Capdevila, Carlos; García de Andrés, Carlos

    2007-01-01

    The addition of about 2 wt.% of silicon to steel enables the production of a distinctive microstructure consisting of a mixture of bainitic ferrite, carbon-enriched retained austenite, and some martensite. With careful design, impressive combinations of strength and toughness have been reported for high-silicon bainitic steels. More recently, it has been demonstrated experimentally that models based on phase transformation theory can be applied successfully to the design of carbide-free baini...

  16. Phase transformations in welded supermartensitic stainless steels

    OpenAIRE

    Carrouge, Dominique

    2002-01-01

    Supermartensitic stainless steels have recently been introduced in the oil and gas industries to substitute more expensive duplex stainless steels for onshore and offshore tubing applications. Although easily joined by arc welding processes, the service life of the supermartensitic welded joint in corrosive environments relies to a large extent on the behaviour of the heat-affected zone (HAZ). The microstructure of the HAZ in these new materials has, until now, received little ...

  17. Cyclic Uniaxial Constitutive Model For Steel Reinforcement

    OpenAIRE

    Kim, Se-Hyung

    2015-01-01

    Reinforced Concrete (RC) structures are common in earthquake-prone areas. During an earthquake, the steel reinforcement is subjected to cyclic strain histories which lead to inelastic response. In the case of rare, strong earthquakes, inelastic buckling and even rupture due to low-cycle fatigue can also occur. The understanding and characterization of the performance of RC structures under earthquake hazards requires the accurate simulation of the inelastic hysteretic behavior of steel re...

  18. Strengthening of HSLA steels by cool deformation

    OpenAIRE

    a Fatehi; Calvo Muñoz, Jessica; Elwazri, A. M.; Yue, S

    2010-01-01

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly...

  19. Strengthening of steels by ceramic phases

    OpenAIRE

    Feng, Yujie

    2013-01-01

    Production of ceramic reinforced thin sheet steel composites for automotive application with low density, high elastic modulus and strength is the aim of current study. Within this work, potential of various ceramic phases and possible processing routes were studied, summarized and compared through literature research. Laboratory production of TiC, TiB2 and Fe2B reinforced steel composites through conventional melting-casting route, twin roller route and powder metallurgy method were carried ...

  20. Ultrahigh Ductility, High-Carbon Martensitic Steel

    Science.gov (United States)

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

    2016-10-01

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

  1. Microstructural studies of advanced austenitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Todd, J. A.; Ren, Jyh-Ching [University of Southern California, Los Angeles, CA (USA). Dept. of Materials Science

    1989-11-15

    This report presents the first complete microstructural and analytical electron microscopy study of Alloy AX5, one of a series of advanced austenitic steels developed by Maziasz and co-workers at Oak Ridge National Laboratory, for their potential application as reheater and superheater materials in power plants that will reach the end of their design lives in the 1990's. The advanced steels are modified with carbide forming elements such as titanium, niobium and vanadium. When combined with optimized thermo-mechanical treatments, the advanced steels exhibit significantly improved creep rupture properties compared to commercially available 316 stainless steels, 17--14 Cu--Mo and 800 H steels. The importance of microstructure in controlling these improvements has been demonstrated for selected alloys, using stress relaxation testing as an accelerated test method. The microstructural features responsible for the improved creep strengths have been identified by studying the thermal aging kinetics of one of the 16Ni--14Cr advanced steels, Alloy AX5, in both the solution annealed and the solution annealed plus cold worked conditions. Time-temperature-precipitation diagrams have been developed for the temperature range 600 C to 900 C and for times from 1 h to 3000 h. 226 refs., 88 figs., 10 tabs.

  2. Stainless steel recycle FY94 progress report

    International Nuclear Information System (INIS)

    The Materials Technology Section (MTS) of the Savannah River Technology Center (SRTC) was asked to demonstrate the practicality of recycling previously contaminated stainless steel components such as reactor heat exchanger heads, process water piping and slug buckets into 208 liters (55 gallon) drums and 2.8 cubic meter (100 ft3) storage boxes. Radioactively contaminated stainless steel scrap will be sent to several industrial partners where it will be melted, decontaminated/cast into ingots, and rolled into plate and sheet and fabricated into the drums and boxes. As part of this recycle initiative, MTS was requested to demonstrate that radioactively contaminated Type 304L stainless steel could be remelted and cast to meet the applicable ASTM specification for fabrication of drums and boxes. In addition, MTS was requested to develop the technical basis of melt decontamination and establish practicality of using this approach for value added products. The findings presented in this investigation lead to the following conclusions: recycle of 18 wt% Cr-8 wt% Ni alloy can be achieved by melting Type 304 stainless steel in a air vacuum induction furnace; limited melt decontamination of the contaminated stainless steel was achieved, surface contamination was removed by standard decontamination techniques; carbon uptake in the as-cast ingots resulted from the graphite susceptor used in this experiment and is unavoidable with this furnace configuration. A new furnace optimized for melting stainless steel has been installed and is currently being tested for use in this program

  3. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  4. Development and formability analysis of TRIP seamless steel tube

    Institute of Scientific and Technical Information of China (English)

    Zhang Zicheng; Zhu Fuxian

    2014-01-01

    In this paper, the production technology of transformation induced plasticity (TRIP) steel was first introduced into the steel tube manufacture field to produce the steel tubes with high strength and plasticity. The TRIP seamless steel tubes with the microstructure of ferrite, bainite, retained austenite and a little martensite were successfully fabricated using a cold-drawn steel tube with two-stage heat treatment technique and continu- ous heat treatment process, respectively. The ring tensile test and cold bend test were carried out to study the formability of the newly developed TRIP seamless steel tube. The results showed that the TRIP seamless steel tubes have a good cold formability, and they are available to be used in the tube hydroforming process. In ad- dition, the equipment of continuous heat treatment developed in the current study can be used to produce TRIP steel tube, and it may serve as an important reference for the industrial production of TRIP steel tube.

  5. Recent Progress in High Strength Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    Zrník J.

    2006-01-01

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

  6. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

    Energy Technology Data Exchange (ETDEWEB)

    Choi, So Young; Kim, Jong Do [Korea Maritime and Ocean University, Busan (Korea, Republic of); Kim, Jong Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-01-15

    This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

  7. Surface topography evolvement of galvanized steels in sheet metal forming

    Institute of Scientific and Technical Information of China (English)

    HOU Ying-ke; YU Zhong-qi; ZHANG Wei-gang; JIANG Hao-min; LIN Zhong-qin

    2009-01-01

    U-channel forming tests were performed to investigate the surface topography evolvement of hot-dip galvanized(GI) and galvannealed(GA) steels and the effects of die hardness on sheet metal forming(SMF). Experimental results indicate that the surface roughness values of the two galvanized steels increase with the number of forming, i.e., the surface topographies of galvanized steels are roughened in SMF. Moreover, GI steel has a better ability of damage-resistance than GA steel. The mechanisms of topography evolvement are different in the forming of GI and GA steels. Scratch is the main form of surface damage in the forming of GI steels. The severity of scratch can be decreased by increasing die hardness. GA steel results in exfoliating of the coating firstly and then severe scratching. The surface topography of galvannealed steels can be improved by increasing die hardness. However, the hardness should not be too high.

  8. Tensile-property characterization of thermally aged cast stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  9. Effect of cathodic protection on the state of steel reinforcement

    International Nuclear Information System (INIS)

    Damage of reinforced concrete structures is mainly caused by chloride or carbonation induced corrosion of steel. Cathodic protection is a very effective measure for corrosion control of steel in concrete, especially in chloride contaminated concrete. In this paper, effect of cathodic protection on the state of steel reinforcement is presented. Cathodic polarization of reinforcements in concrete was done under different submerged conditions. Cyclic potentiodynamic tests were used to determine the effect of cathodic protection on the behavior of the steel. Pitting appeared on the non-protected steel, but was not observed on the cathodically protected steel. microscopic photographs show that a close film exists on the protected steel, while the non-protected steel's film is loose. Investigated results have proved the effect of cathodic protection in restoring or strengthening passive film on the steel reinforcement

  10. The Self-assembly Synthesis and Structure of a Novel 1-D Lead Iodide Adduct: [(Pb2I5)(L-H+)· 2DMF]n (L=Piperazine)%一种新颖一维铅碘聚合物[(Pb2I5)(L-H+)·2DMF]n(L=Piperazine)的自组装合成和晶体结构

    Institute of Scientific and Technical Information of China (English)

    李浩宏; 陈之荣; 黄长沧; 赵斌; 肖荣平; 倪朝霞

    2005-01-01

    The lead iodide adduct [(Pb2I5)(L-H+) ·2DMF]n (L=piperazine) has been prepared by self-assembly and structurally characterized. It presents one dimensional structure and crystallizes in Triclinic, P1 space group with the crystal cell parameter: a=0.92206(18) nm, b=1.237 5(3) nm, c=1.297 2(3) nm,α=99.05(3)°, β=102.98(3)°, y=mula C16H43NsO4Pb4I10 and Mr=2 509.39, the final R=0.053 3 and wR=O.146 4 for 3 889 observed reflections with I>2σ(Ⅰ). CCDC: 250760.

  11. Current Developments of Alloyed Steels for Hot Strip Roughing Mills : Characterization of High-Chromium Steel and Semi-High Speed Steel

    OpenAIRE

    LECOMTE-BECKERS, Jacqueline; Sinnaeve, Mario; Tchuindjang, Jérôme Tchoufack

    2012-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill - high chromium steel (HCS) and semi-high-speed steel (semi-HSS), In this paper, the new semi-high-speed steel grade is studied

  12. High Mn austenitic stainless steel

    Science.gov (United States)

    Yamamoto, Yukinori [Oak Ridge, TN; Santella, Michael L [Knoxville, TN; Brady, Michael P [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Liu, Chain-tsuan [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  13. Creep strength and ductility of 9 to 12% chromium steels

    DEFF Research Database (Denmark)

    Hald, John

    2004-01-01

    Steels", which covers creep data development and analysis for parent materials and welds of all ferritic creep resistant steels ranging from low alloy steels up to 12%Cr steels. The opinions stated in the paper represent the views of the author rather than the whole ECCC WG3A group.......The present paper focuses in on long-term creep properties of parent material of the new 9-12%Cr creep resistant steels, P91, E911 and P92 developed for use in advanced ultrasupercritical power plants. These steels have been at the center of activities in the ECCC Working Group 3A (WG3A) "Ferritic...

  14. Achievements of New Generation Steel Project in China

    Institute of Scientific and Technical Information of China (English)

    Weng Yuqing

    2004-01-01

    Major achievements of the national project, Fundamental Research on New Generation of Iron and Steel Materials in China (NG Steel), are reviewed in the paper. Ultrafine grained steel technology, based on deformation induced ferrite transformation (DIFT)and successive microstructure changes, is illustrated for grain refinement in both plain low carbon steel and microalloyed steel. Delayed fracture resistance of alloy structure steel can be improved through prior austenite grain refinement. It is shown by results that nano scale precipitates play an important role to grain refinement in thin slab casting and rolling (TSCR)process. Progresses on super cleanliness, high homogeneity, welding and metallurgical process simulation are also briefly introduced.

  15. Redemption of asthma pharmaceuticals among stainless steel and mild steel welders

    DEFF Research Database (Denmark)

    Kristiansen, Pernille; Jørgensen, Kristian Tore; Hansen, Johnni;

    2015-01-01

    PURPOSE: The purpose was to examine bronchial asthma according to cumulative exposure to fume particulates conferred by stainless steel and mild steel welding through a proxy of redeemed prescribed asthma pharmaceuticals. METHODS: A Danish national company-based historical cohort of 5,303 male ever...... was estimated by combining questionnaire data on welding work with a welding exposure matrix. The estimated exposure accounted for calendar time, welding intermittence, type of steel, welding methods, local exhaustion and welding in confined spaces. Hazard ratios (HRs) with 95 % confidence intervals (CIs) were...... nonsignificant increased rate of redemption of asthma medicine was observed among high-level exposed stainless steel welders in comparison with low-level exposed welders (HR 1.54, 95 % CI 0.76-3.13). This risk increase was driven by an increase risk among non-smoking stainless steel welders (HR 1.46, 95 % CI 1...

  16. Analysis of the Behaviour of Composite Steel and Steel Fiber Reinforced Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Mindaugas Petkevičius

    2011-04-01

    Full Text Available There was a pending influence of steel fiber on the strength and stiffness of composite steel–concrete slabs under statical short–time load. Steel profiled sheeting and steel fiber reinforced concrete were used for specimens. Four composite slabs were made. Experimental investigations into the behaviour and influence of steel fiber reinforced concrete in composite slabs were conducted. Transverse, longitudinal, shear deformation and deflection of the slab were measured. The results indicated that the use of steel fiber in composite slabs was effective: strength was 20–24 % higher and the meanings of deflections under the action of the bending moment were 0,6MR (where MR is the bending moment at failure of the slabs and were 16–18 % lower for slabs with usual concrete. Article in Lithuanian

  17. Stress analysis of a large diameter, heated pipeline in mountainous terrain

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo, Dario R.; Riccillo, Domingo; Curle, Ronald K. [TECHINT S.A. (Brazil)

    2003-07-01

    The primary goals of modern pipeline design and construction projects, are safety and low cost. High strength steels such as API-5L Gr. X70 reduce installed weights but translate into high D/t ratios. Modern manufacturing methods, used produce API grade pipes, increase yield strength with minimal changes to the ultimate tensile strength (UTS). The trend toward the use of high strength pipe reduces costs, but correspondingly increases D/t ratios. There are significant challenges in stress and rupture analysis to ensure stability under loading conditions that include static and transient pressures, high temperatures, dead weights, and seismic forces. (author)

  18. Strengthening of HSLA steels by cool deformation

    Energy Technology Data Exchange (ETDEWEB)

    Fatehi, A., E-mail: arya.fatehi@gmail.com [Department of Mining, Metals and Materials Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 2B2 (Canada); Calvo, J.; Elwazri, A.M.; Yue, S. [Department of Mining, Metals and Materials Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 2B2 (Canada)

    2010-06-25

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly dispersed precipitates in the steel matrix. In the present study, the effects of Nb and Cu on mechanical properties and corresponding microstructures in steels with different levels of cool deformation are investigated. The mechanical properties of the samples were determined using the shear punch test and the microstructure was examined by scanning and transmission electron microscopy. Thermodynamic simulations with FactSage were done to further analyze the precipitation possibility of different elements. It has been found that these alloying elements respond very well to cool deformation, with the strength being highest in steels containing both Nb and Cu. However, a cool deformation effect in the non-Nb and Cu bearing steel is also observed. In all cases, it was confirmed that precipitation plays a key role in the effect of cool deformation, with much of the precipitation taking place dynamically. Nevertheless, static processes also seem to have a measurable effect on room temperature properties. Even low amounts of copper (e.g. {approx}0.4 wt%) can contribute to strengthening of the steel. The Cu addition is found to affect the mechanical properties by affecting the precipitation and growth of Nb compounds.

  19. Metallurgical products of microalloy constructional steels

    Directory of Open Access Journals (Sweden)

    W. Ozgowicz

    2011-01-01

    Full Text Available Purpose: The aim of the paper is a monographic presentation, based on investigations connected with the elaboration of new kinds of microalloy steels and a technique of heat and thermo-mechanical treatment in the production of a selected group of metallurgical products.Design/methodology/approach: The influence of the chemical composition and metallurgical purity on the homogenisation of austenite was analysed, as well as thermally activated processes and phase transformations in the course of deformation and controlled cooling conditions, concerning micradditives Nb, V, Ti, B and metallurgical products.Findings: The chemical composition of the obtained constructional steels with microadditives was quoted, as well as the technological conditions of forging and rolled products required for industrial purposes.Research limitations/implications: The results of investigations concerning the structure and mechanical properties have been presented, as well as the resistance to fracture, mainly of thick plates and hand-forged and drop-forged products and also elements of sheet structures for the automotive industry, made of AHSS steels.Practical implications: The results of the author’s own investigations concerning microalloy steels indicate the actual possibility of their application in practice in many steelworks, particularly in plants producing semi products and final metallurgical products, among others in hot rolling plants and forging shops, first of all in machine building and automotive industry.Originality/value: The application of modern metallurgical technologies and metalforming has been suggested for selected metallurgical products of microalloy steels of the type HSLA with a ferrite-bainite, bainite or tempered martensite structure and also of HSS steels and UHSS steel with a wide range of mechanical properties and technological formability, which is essential in the case of products of the automotive industry.

  20. Strengthening of HSLA steels by cool deformation

    International Nuclear Information System (INIS)

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly dispersed precipitates in the steel matrix. In the present study, the effects of Nb and Cu on mechanical properties and corresponding microstructures in steels with different levels of cool deformation are investigated. The mechanical properties of the samples were determined using the shear punch test and the microstructure was examined by scanning and transmission electron microscopy. Thermodynamic simulations with FactSage were done to further analyze the precipitation possibility of different elements. It has been found that these alloying elements respond very well to cool deformation, with the strength being highest in steels containing both Nb and Cu. However, a cool deformation effect in the non-Nb and Cu bearing steel is also observed. In all cases, it was confirmed that precipitation plays a key role in the effect of cool deformation, with much of the precipitation taking place dynamically. Nevertheless, static processes also seem to have a measurable effect on room temperature properties. Even low amounts of copper (e.g. ∼0.4 wt%) can contribute to strengthening of the steel. The Cu addition is found to affect the mechanical properties by affecting the precipitation and growth of Nb compounds.

  1. Mechanical properties of irradiated 9Cr-2WVTa steel

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States); Rieth, M. [Forschungszentrum Karlsruhe (Germany). Inst. fuer Materialforschung II

    1998-09-01

    An Fe-9Cr-2W-0.25V-0.07Ta-0.1C (9Cr-2WVTa) steel has excellent strength and impact toughness before and after irradiation in the Fast Flux Test Facility and the High Flux Reactor (HFR). The ductile-brittle transition temperature (DBTT) increased only 32 C after 28 dpa at 365 C in FFTF, compared to a shift of {approx}60 C for a 9Cr-2WV steel--the same as the 9Cr-2WVTa steel but without tantalum. This difference occurred despite the two steels having similar tensile but without tantalum. This difference occurred despite the two steels having similar tensile properties before and after irradiation. The 9Cr-2WVTa steel has a smaller prior-austenite grain size, but otherwise microstructures are similar before irradiation and show similar changes during irradiation. The irradiation behavior of the 9Cr-2WVTa steel differs from the 9Cr-2WV steel and other similar steels in two ways: (1) the shift in DBTT of the 9Cr-2WVTa steel irradiated in FFTF does not saturate with fluence by {approx}28 dpa, whereas for the 9Cr-2WV steel and most similar steels, saturation occurs at <10 dpa, and (2) the shift in DBTT for 9Cr-2WVTa steel irradiated in FFTF and HFR increased with irradiation temperature, whereas it decreased for the 9Cr-2WV steel, as it does for most similar steels. The improved properties of the 9Cr-2WVTa steel and the differences with other steels were attributed to tantalum in solution.

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

    KAUST Repository

    Itty, Pierre-Adrien

    2014-06-01

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

  3. Effect of thermomechanical processing on microstructure, texture, and anisotropy in two Nb microalloyed steels

    Science.gov (United States)

    Akbarzadeh, Abbas

    The process parameters that affect the anisotropy of mechanical properties of two Nb microalloyed linepipe steels (grades X-70 and X-80) were examined by controlled rolling and accelerated cooling on a pilot mill. The rolling schedules were first simulated by multi-pass torsion testing so as to determine the critical temperatures, such as Tsbnr and Arsb3. Using the torsion test results, two finish rolling temperatures were chosen so as to be above and below the Asb3 (in the gamma + alpha region). Two reheat temperatures were selected to study the effect of prior austenite grain size. The properties of air cooled samples are compared with those of specimens cooled at two different rates; in each case, cooling was interrupted at one of three different temperatures. The textures were measured by x-ray diffractometry and are presented in the form of ODF plots and skeleton lines. The yield strengths were measured by carrying out tensile tests along directions inclined at increasing angles to the rolling direction. The state of the pancaked austenite before transformation was characterized in terms of the effective interfacial area. It is shown that this parameter determines the sharpness of the transformation texture because it accounts for both the amount of pancaking strain applied to the austenite before transformation and the austenite grain size. Another important factor affecting texture development during transformation is the rate of cooling, as it determines the dislocation density present on each active slip system. The results of hardness testing, texture measurement, and mechanical testing showed that a moderate cooling rate and a medium cooling interruption temperature lead to the best combination of a fine microstructure and a desirable texture. It is shown that accelerated cooling increases both the yield strength and the planar anisotropy of the yield strength, the latter property rising to a maximum in the samples associated with the lowest cooling

  4. The Synchrotron Radiation for Steel Research

    Directory of Open Access Journals (Sweden)

    Piyada Suwanpinij

    2016-01-01

    Full Text Available The synchrotron X-ray radiation is a great tool in materials characterization with several advantageous features. The high intensity allows clear interaction signals and high energy of X-ray yields higher sampling volume. The samples do not need extra preparation and the microstructure is therefore not affected. With the tunability of the X-ray energy, a large range of elements and features in the samples can be investigated by different techniques, which is a significant difference between a stand-alone X-ray tube and synchrotron X-ray. Moreover, any experimental equipment can be installed through which the synchrotron beam travels. This facilitates the so-called in situ characterization such as during heat treatment, hot deformation, chemical reaction or welding. Although steel which possesses rather high density requires very high energy X-ray for large interaction volume, lower energy is still effective for the investigation of local structure of nanoconstituents. This work picks up a couple examples employing synchrotron X-ray for the characterization of high strength steels. The first case is the quantification of precipitates in high strength low alloyed (HSLA steel by X-ray absorption spectroscopy. The other case is the in situ X-ray diffraction for phase fraction and carbon partitioning in multiphase steels such as transformation induced plasticity (TRIP steel.

  5. Development of the microalloyed constructional steels

    Directory of Open Access Journals (Sweden)

    J. Adamczyk

    2005-12-01

    Full Text Available Purpose: The aim of the paper is to present the development and the technical importance of the HSLA-typemicroalloyed constructional steels (High Strength Low Alloy in selected industry branches.Design/methodology/approach: A mechanism of the interaction of Nb, Ti, V and B microadditions introducedinto the steel on mechanical properties of selected metallurgical products with the fine-grained structure,forming under the properly selected hot-working conditions with the of (M-Nb,Ti,V; X-N,C interstitial phasesMX-type is discussed.Findings: The requirements concerning the metallurgical process, continuous casting of steel and the necessityof adjusting the hot-working conditions to the precipitation kinetics of the dispersive MX phases particles inaustenite, in the controlled rolling or thermo-mechanical treatment processes are indicated.Research limitations/implications: The continuation of investigations concerning the thermo-mechanicalrolling of automotive sheets with the multiphase structure of microalloyed steels is planned.Practical implications: The indicated data, coming also from the own research, are of practical use in relationto manufacturing the metallurgical products and machine elements of high strength and crack resistance, alsoat low temperatures.Originality/value: The results contribute to the development of rolling and forging technologies of themicroalloyed steel (HSLA elements produced using the energy-saving thermo-mechanical treatment methods.

  6. Nanostructuring steel for injection molding tools

    International Nuclear Information System (INIS)

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro- and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced. (paper)

  7. Aging degradation of cast stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the ..cap alpha..' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450/sup 0/C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450/sup 0/C. 18 refs., 13 figs.

  8. Fabrication and ageing of cast austenitic steels

    International Nuclear Information System (INIS)

    An investigation has been undertaken to determine the magnitude of any reduction in properties which may occur in cast duplex stainless steels and weldments during long term exposure to reactor operating conditions. Test panels were fabricated in CF3 stainless steel by a manual metal arc (MMA) process using 19.9.L (Type 308L) consumables. The mechanical properties and intergranular corrosion resistance of parent material and weldments were measured following accelerated ageing at 3750 and 4000C for up to 10,000 hours. Both the impact energy and J/sub R/ fracture toughness properties of the cast austenitic/ferritic stainless steel were reduced following aging at 4000C for 10,000 hours, whereas austenitic stainless steel MMA weld metals exhibited a reduction in J/sub R/ fracture toughness but no change in impact energy. Even in the unaged state, MMA weld metals were shown to have a much lower resistance to stable crack growth than the parent cast steel, and, following aging, there is a further reduction in the ductile tearing resistance of such weld metals. Therefore, in any assessment of the structural integrity of the reactor coolant pump bowl for a pressurized water reactor (PWR), the weld metal fracture properties during service are likely to be of considerable importance

  9. Equilibrium Model of Precipitation in Microalloyed Steels

    Science.gov (United States)

    Xu, Kun; Thomas, Brian G.; O'Malley, Ron

    2011-02-01

    The formation of precipitates during thermal processing of microalloyed steels greatly influences their mechanical properties. Precipitation behavior varies with steel composition and temperature history and can lead to beneficial grain refinement or detrimental transverse surface cracks. This work presents an efficient computational model of equilibrium precipitation of oxides, sulfides, nitrides, and carbides in steels, based on satisfying solubility limits including Wagner interaction between elements, mutual solubility between precipitates, and mass conservation of alloying elements. The model predicts the compositions and amounts of stable precipitates for multicomponent microalloyed steels in liquid, ferrite, and austenite phases at any temperature. The model is first validated by comparing with analytical solutions of simple cases, predictions using the commercial package JMat-PRO, and previous experimental observations. Then it is applied to track the evolution of precipitate amounts during continuous casting of two commercial steels (1004 LCAK and 1006Nb HSLA) at two different casting speeds. This model is easy to modify to incorporate other precipitates, or new thermodynamic data, and is a useful tool for equilibrium precipitation analysis.

  10. Thermodynamic aspects of inclusion engineering in steels

    Institute of Scientific and Technical Information of China (English)

    A. Costa e Silva

    2006-01-01

    Tailoring non-metallic inclusions in accordance to the desired effect on steel properties has gained widespread acceptance in the last decades and has become known as "inclusion engineering". Effective inclusion engineering involves three steps: (a) a good knowledge of how inclusions influence properties, (b) understanding what is the effect of each type of inclusions on these properties and thus which is the most desirable inclusion in a given product and (c) adjusting the processing parameters to obtain these inclusions. A significant portion of the process adjustment is done during steel refining, where the steel can be tailored so that the desired chemical composition of the non-metallic inclusions that will precipitate can be altered. Understanding the relations between steel chemistry, processing variables and inclusion chemical composition requires significant understanding of the thermodynamics of the systems involved. These complex equilibrium calculations are best done using computational thermodynamics. In this work some of the basic techniques used to control inclusion composition are reviewed and the thermodynamic information required to perform this task is presented. Several examples of the application of computational thermodynamics to inclusion engineering of different steels grades are presented and compared with experimental results, whenever possible. The potential and limitations of the method are highlighted, in special those related to thermodynamic data and databases.

  11. Process development of thin strip steel casting

    Energy Technology Data Exchange (ETDEWEB)

    Sussman, R.C.; Williams, R.S.

    1990-12-01

    An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

  12. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 4500C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the α' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 4500C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 4500C. 18 refs., 13 figs

  13. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich α' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by α' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 4500C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 4500C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed

  14. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    Science.gov (United States)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-05-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  15. HTPro: Low-temperature Surface Hardening of Stainless Steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2013-01-01

    Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance.......Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance....

  16. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present contribution gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular, the...

  17. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present contribtion gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular, the...

  18. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    Science.gov (United States)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-09-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  19. Nickel-free austenitic stainless steels for medical applications

    Directory of Open Access Journals (Sweden)

    Ke Yang and Yibin Ren

    2010-01-01

    Full Text Available The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength and good plasticity, better corrosion and wear resistances, and superior biocompatibility compared to the currently used 316L stainless steel, the newly developed high-nitrogen nickel-free stainless steel is a reliable substitute for the conventional medical stainless steels.

  20. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M.; Fontaine, G. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Unite de Catalyse et Chimie du solide UMR 8181 Bat C3, USTL, F-59655 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)], E-mail: Michel.Traisnel@ensc-lille.fr; Lerasle, O.; Genet, N. [TOTAL France, Centre de Recherche de Solaize, Chemin du canal, BP 22, F-69360 Solaize (France)

    2008-08-30

    The efficiency of a new triazole derivative, namely, 2-{l_brace}(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1-yl)methyl]amino{r_brace} ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  1. Interaction model of steel ladle of continuous caster in steel works

    Directory of Open Access Journals (Sweden)

    Huang Bang Fu

    2016-01-01

    Full Text Available For further research on the precondition and interoperability model of interaction ladles among continuous caster, this article takes steel ladle of Y steel works as the object of research. On the basis of turnover number calculation model of single cast steel ladle, the relationship between cast number and the turnover number and turnover times and last turnover number are further analyzed. The simulation of steel ladle turnover rules was taken on the 2 continuous casters with Gantt chart. After that, the relationships between turnover number and last turnover number and non-turnover number are researched deeply. Combining with the Gantt chart, the expressions of start casting time and empty ladle ending time and heavy ladle starting time were put forward. The precondition of steel ladle interaction is obtained, which means the exchange ladle should not undertaking transport task in first stop continuous caster, and the empty ladle end time of exchange ladle of first stop continuous caster should early than the heavy ladle start time of last stop continuous caster. After applying the model to practice, 3 steel ladles of No.2 continuous caster can be reduced. This research results is supplying theoretical basis for steel ladle controlling and production organization optimization, and enriches the theory and method of metallurgical process integration.

  2. 注水介质中喹啉缓蚀剂对管线钢的缓蚀作用研究%Research on Corrosion Inhibition Effect of Quinoline Inhibitor in Injection Water Media on Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    张颖; 董国强; 胡凌艳

    2015-01-01

    ABSTRACT:Objective To investigate the growth pattern of quinoline adsorption film on X70 steel surface in the context that the injection water with corrosion inhibitors can effectively prevent the oil devices from corrosion and the film formed on the pipeline surface can alleviate the injection water corrosion. Methods The data obtained from scratch test were calculated using high field ion conduction model by potentiostatic rapid scratch method. Results The results showed that the high field ion conduction model was only applicable for a part of adsorbing process of quinoline. The mathematic simulation by further function fitting found that the growth pattern of quinoline adsorption film on X70 steel surface in simulated media followed the equation: J(t)=C1exp(-αt)+C2 exp(-βt)+C0 . Conclusion At the concentration of 0. 3%, 0. 6% ( mass fraction) quinoline, current fluctuated obviously and the stability of the forming film was worse. There was a possibility of local corrosion in scratch area. At the concentration of 0. 9%(mass fraction) quinoline, the goodness of fit between the simulated curve and the true current decay curve reached 0. 9983, the current fluctuated slightly and the stability of inhibitor adsorption film was better. In the injection water media, the content of quin-oline was higher, the quality of the forming film was better and the difference of the current density was smaller before and after scratch. The growth state of the adsorption film on the scratch surface and no-scratch surface were in a consistent state. The quino-line adsorption film could rapidly form on the damaged steel surface at the higher concentration which had a quick and overall pro-tective effect for the sample.%目的:在注水介质中加入喹啉缓蚀剂可有效防止石油设备的腐蚀,注水管表面形成的钝化膜可减小注水介质的腐蚀,研究喹啉缓蚀剂在X70钢表面的吸附膜的生长规律。方法采用恒电位快速划伤法,利用高场

  3. Rare Earth Additions in Continuously Cast Steel

    Science.gov (United States)

    Wilson, William G.; Heaslip, L. J.; Sommerville, I. D.

    1985-09-01

    Rare earth (lanthanide metals) addiiions to continuously cast steel are particularly advantageous because of their ability to refine as-cast structures, reduce segregation and increase hot ductility at temperatures just below that of solidification. The complete shape control of sulfides in steels containing Rare Earth Metals (REM), whether continuously cast or ingot cast, is primarily responsible for improvements in ductility related mechanical properties, weldability, fatigue resistance and resistance to hydrogen damage. Complete sulfide shape control can be obtained with REM additions at sulfur levels as high as.020%. The greatest improvements, however, are obtained with REM additions to low sulfur steels. However, to achieve full operational advantages afforded by REM, nozzle blockage problems must be circumvented. Water model studies indicate a possible solution.

  4. CO2 emissions in the steel industry

    Directory of Open Access Journals (Sweden)

    M. Kundak

    2009-07-01

    Full Text Available Global CO2 emissions caused by the burning of fossil fuels over the past century are presented. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. Reductions in CO2 emissions as a result of technological improvements and structural changes in steel production in industrialized countries during the past 40 years are described. Substantial further reductions in those emissions will not be possible using conventional technologies. Instead, a radical cutback may be achieved if, instead of carbon, hydrogen is used for direct iron ore reduction. The cost and the ensuing CO2 generation in the production of hydrogen as a reducing agent from various sources are analysed.

  5. Activity of Reducing Steel Slag of EAF

    Institute of Scientific and Technical Information of China (English)

    GUO Chinhsiang; HWANG Chaolung; LIN Tingyi

    2011-01-01

    Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF)steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

  6. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H; Koenig, H. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  7. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    Science.gov (United States)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  8. Complex Protection of Vertical Stainless Steel Tanks

    Directory of Open Access Journals (Sweden)

    Fakhrislamov Radik Zakievich

    2014-03-01

    Full Text Available The authors consider the problem of fail-safe oil and oil products storage in stainless steel tanks and present the patented tank inner side protection technology. The latter provides process, ecological and fire safety and reducing soil evaporation of oil products, which is a specific problem. The above-mentioned technology includes corrosion protection and heat insulation protection providing increase of cover durability and RVS service life in general. The offered technological protection scheme is a collaboration of the author, Steel Paint GmbH firm and JSC “Koksokhimmontazhproyekt”. PU foam unicomponent materials of Steel Paint GmbH firm provide the protection of tank inner side and cover.

  9. Microstructure and cleavage in lath martensitic steels

    Directory of Open Access Journals (Sweden)

    John W Morris Jr, Chris Kinney, Ken Pytlewski and Y Adachi

    2013-01-01

    Full Text Available In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified 'classic' lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov–Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage.

  10. Low carbon manganese-nickel-niobium steel

    International Nuclear Information System (INIS)

    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 11000C to 13000C and of finish rolling temperatures between 7100C and 9300C 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)

  11. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  12. Microstructure and cleavage in lath martensitic steels

    International Nuclear Information System (INIS)

    In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni) steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified ‘classic’ lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov–Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage. (paper)

  13. Investigation of Fecraly Coating on Corrosion Behaviour of Mild Steel

    OpenAIRE

    Joseph B. AGBOOLA

    2009-01-01

    Steel has found wide application in hot rolling equipments in the steel industry and the oil rig structures in sea water. These equipments are frequently subjected to corrosive and temperature condition which causes severe damage to them, hence the need to develop steel suitable to withstand these conditions in terms of surface treatment. This research work investigates the effect of FeCrAlY coating on mild steel under high temperature and aggressive environment. Iron based coatings are used ...

  14. The Sino-Japan Steel Trade Negotiations Framework

    OpenAIRE

    Ian Dickson

    1996-01-01

    A factor influencing China's integration with world steel markets is steel's status as a canalised or "designated" commodity under Chinese trade laws. Canalisation limits the number of enterprises permitted to engage in import operations. Canalisation is particularly strict in the case of steel imports from Japan, the largest country supplier of ferrous metal products to China. Until mid-1995, steel supplies were organised under a system of bi-yearly contract negations between the Chinese sin...

  15. Contributions to steel semi-finished parts quality improvements

    International Nuclear Information System (INIS)

    The quality of finite steel products depends on steel content of hydrogen. On steel elaboration, in order to remove the dissolved hydrogen, at least one ladle secondary treatment is needed. The paper introduces the results obtained in the increase of hydrogen removal output, during steel secondary treatment inside the LF installation. Correlations were established between the hydrogen removal rate and the parameters of the secondary treatment (bubbling flow, bubbling time and bubbling pressures)

  16. Enhanced Inclusion Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R. C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  17. Enhanced Incluison Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R.C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  18. 46 CFR 154.172 - Contiguous steel hull structure.

    Science.gov (United States)

    2010-10-01

    ... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for the... published in “Rules for Building and Classing Steel Vessels”, 1981 −10 °C (14 °F) T≤112.5 mm (1/2 in.) B 12... American Bureau of Shipping published in “Rules for Building and Classing Steel Vessels”, 1981....

  19. Mechanism of an acoustic wave impact on steel during solidification

    OpenAIRE

    K. Nowacki; P. Musiał; T. Lis

    2013-01-01

    Acoustic steel processing in an ingot mould may be the final stage in the process of quality improvement of a steel ingot. The impact of radiation and cavitation pressure as well as the phenomena related to the acoustic wave being emitted and delivered to liquid steel affect various aspects including the internal structure fragmentation, rigidity or density of steel. The article provides an analysis of the mechanism of impact of physical phenomena caused by an acoustic wave affecting the qual...

  20. Guidelines for the Protection of Steel Piles : Corrosive Marine Environment

    OpenAIRE

    Rhodes, Graham

    2011-01-01

    The corrosion of steel is a common phenomenon. In a marine environment, steel is corroded at an accelerated rate due to the atmospheric conditions. To combat this corrosion, steel piles are coated in order to protect them. As a major supplier of steel piles, Rautaruukki Oyj (Ruukki) commissioned this project in order to streamline their coating process. Currently Ruukki supplies a different coating system for almost every job; the aim of the project was to reduce the number of systems used to...

  1. Case Hardening of Hardox 450 Steel for Increased Ballistic Strength

    OpenAIRE

    Buberg, Tor Arne

    2011-01-01

    AbstractSteel alloys are the material that is most used in protective constructions today. The reason is the overall good properties of steels, with its high strength and hardness, high ductility, high formability and relatively low cost compared to other materials. Even though armour steels are affordable, work is done to limit expenses from production or come up with new and less expensive alloys.Case hardening is a technique for production of steel with a very hard and durable surface whil...

  2. Bending resistance of composite steel truss and concrete beam

    OpenAIRE

    Silva, Mickael; Piloto, P.A.G.; Roque, Sérgio; VILA REAL Paulo; Plizzari, Giovanni

    2013-01-01

    This study presents the numerical simulation of the bending resistance of CSTCB in stage 1 (element made only by the self-supported steel truss and base plate). Two different base plates were considered (Steel and Concrete) and two different types of steel trusses (Type I and II). The numerical results are also compared with analytical results, assuming the full interaction between steel truss and concrete, neglecting the tensile strength of concrete, considering the effective area of concret...

  3. Nickel-free austenitic stainless steels for medical applications

    OpenAIRE

    Ke Yang and Yibin Ren

    2010-01-01

    The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainl...

  4. Discussion about Several Problems on Evaluating X-ray Image According to API SPEC 5L%API SPEC 5L标准射线底片评定过程中的几个问题的探讨

    Institute of Scientific and Technical Information of China (English)

    王晨; 侯永高; 张道峰; 闻康

    2007-01-01

    @@ 随着西气东输等长输管线的建立,我国又迎来了一个管线建设的新的高峰.钢管生产检测在国内无损检测所占比例逐渐加大.钢管厂常年使用的标准主要是GB 9711.1-1997、GB 9711.2-1999和API SPEC 5L.在API SPEC 5L标准的具体使用过程中,由于美国标准体系和工作惯例与我国在其它领域采用的射线检测存在一些不同,造成对标准底片评定的理解存在一定的模糊,下面将在常年使用API SPEC 5L标准的经验中发现的一些问题提出来,供同行参考和斧正.

  5. Initial oxidation of duplex stainless steel 2205

    Energy Technology Data Exchange (ETDEWEB)

    Donik, E.; Kocijan, A.; Jenko, M. [Institute of metals and technology, Ljubljana (Slovenia)

    2009-07-01

    Due to superior mechanical and corrosion properties of duplex stainless steels which result in weight reduction of the constructions, thus contributing to the decreases in total costs and also due to the large and versatile usage of the alloy, duplex stainless steel is gradually displacing stainless steels of the AISI 300 series. Pickling of duplex stainless steel has proven to be much more difficult than that of standard austenitic grade (AISI 300 series). There is no complete agreement in the literature on scale (high temperature oxidation) dissolution mechanism in neutral pickling solutions. During annealing, duplex stainless steel is heated in annealing furnace up to 1050 C and is kept at this temperature for some time to soften the metal in order to release the work hardening induced by hot and cold rolling. The elimination of surface defects by forming the oxide scale is required to improve the corrosion resistance. Three different techniques were used to produce thin oxide layers on polished and sputter cleaned duplex stainless steel samples. They were exposed to 10{sup -5} mb pure oxygen inside the vacuum chamber, exposed to ambient conditions for 24 hours and plasma oxidized. Oxide layers thus produced were analysed using XPS depth profiling for determination of the oxide layer's composition with depth. It was found that all techniques produce oxide layer with different traces of metallic components and with chromium oxide maximum concentration shifted towards the oxide layer - bulk metal interface. Depletion of Cr in bulk immediately below the interface was also observed. Simplified ARXPS procedure was used to corroborate thickness estimates for thinnest oxide layers. (authors)

  6. Electropolishing and chemical passivation of austenitic steel

    Directory of Open Access Journals (Sweden)

    A. Baron

    2008-12-01

    Full Text Available Purpose: The aim of the paper is investigations a dependence between the parameters of the electrochemical treatment of austenitic steel and their electrochemical behavior in Tyrod solution.Design/methodology/approach: Specimens (rode 30 mm × ø1 mm were to give in to the surface treatment – mechanically polishing, electrolytic polishing and passivation with various parameter. Electrochemical investigations concerning the corrosion resistance of austenitic steel samples were carried out by means of the potentiodynamic and electrochemical impedance spectroscopy method.Findings: The analysis of the obtained results leads to the conclusion that chemical passivation affects also the chemical composition of the passive layer of steel and changes its resistance to corrosion. Electrolytic polishing improves corrosion resistance, as can be proved by the shift of the value of the corrosion potential and break-down potential of the passive layer and the initiation of pittings.Research limitations/implications: The obtained results are the basis for the optimization of anodic passivation parameters of the austenitic steel as a metallic biomaterial. The future research should be focused on selected more suitable parameters of the electrochemical impedance spectroscopy test to better describe process on the solid/ liquid interface.Practical implications: In result of the presented investigations it has been found that the best corrosion resistance can be achieved thanks to the application of electrolytic polishing of the steel in a special bath and chemical passivation in nitric (V acid with an addition of chromic (VI acid temperature t = 60°C for one hour.Originality/value: The enormous demand for metal implants has given rise to a search for cheap materials with a good biotolerance and resistance to corrosion. Most commonly used are steel implants assigned to remain in the organism for some limited time only. It was compare two electrochemical methods

  7. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H. [ThyssenKrupp Steel AG, Eberhardstrasse 12, 44145 Dortmund (Germany); Mattissen, D.; Schaumann, T.W. [ThyssenKrupp Steel AG, Duisburg (Germany)

    2006-09-15

    Advanced multiphase steels offer a great potential for bodies-in-white through their combination of formability and achievable component strength levels. They are first choice for strength and crash-relevant parts of challenging geometry. The intensive development of high-strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Fortschrittliche Multiphasen-Staehle eroeffnen wegen der inzwischen erreichbaren Kombination aus Umformbarkeit und Bauteilfestigkeit ein enormes Potenzial fuer Rohkarosserien. Sie stellen eine erste Wahl dar, wenn es um Festigkeit und um Crashsicherheit geht und besondere Anforderungen an die Bauteilgeometrien gestellt werden. Bei ThyssenKrupp hat die Entwicklung hochfester Multiphasen-Staehle in Verbindung mit dem Feuerverzinken zur Realisierung von Blechhalbzeugen gefuehrt, die hervorragend formbar sind. Es werden heute feuerverzinkte Komplexphasenstaehle neben den bewaehrten kaltgewalzten Dualphasen(DP) - und Retained Austenit(RA)-Staehlen produziert. Die neuen kontinuierlich gegluehten Stahlvarianten mit Festigkeiten bis zu 1000 MPa in Kombination mit der bei Strukturbauteilen im Automobilbau geforderten Duktilitaet nutzen sowohl die klassischen Vorteile des Mikrolegierens aus und dazu die Prinzipien, die man bei DP- und TRIP-Staehlen anwendet. Eine weitere Verbesserung des Eigenschaftsprofils wird mit dem

  8. Hydrogen degradation of high strength weldable steels

    Directory of Open Access Journals (Sweden)

    J. Ćwiek

    2007-01-01

    Full Text Available Purpose: Purpose of this paper is presentation of hydrogen degradation issue of high strength steels andespecially their welded joints. Establishing of applicable mechanisms of hydrogen-enhanced cracking was theaim of performed research.Design/methodology/approach: High strength quenched and tempered steels grade S690Q were used. Weldedjoints were prepared with typical technology used in shipyards. Susceptibility to hydrogen degradation in seawater under cathodic polarization was evaluated with the use of mechanical tests. Various kinds of loads wereapplied, i.e. monotonically increasing static, constant, and cyclic. Appropriate measures of hydrogen degradationwere chosen and analyzed. Mechanisms of hydrogen degradation were detected and established on the basis ofscanning electron microscopy (SEM observation of fracture samples surface.Findings: Tested high strength steels and their welded joints are susceptible to hydrogen embrittlement whenevaluated using a slow strain rate test (SSRT. On contrary, these steels and welded joints have high resistance tohydrogen delayed cracking under a constant load test. Significant reduction of a fatigue life time due to hydrogenabsorption has been observed during severe low-cycle fatigue tests.Research limitations/implications: There is no possibility to perform direct observation of exact hydrogenassistedcracking mechanisms in massive samples. Valid hydrogen-enhanced cracking model could be onlydeducted from degradation evidences like plasticity loss and fracture modes.Practical implications: Tested quenched and tempered S690Q steel grades could be safely utilized for marinewelded constructions under cathodic polarization. Hydrogen-assisted cracking should not occur unless a hugeoverprotection and plastic deformation take place.Originality/value: Hydrogen-enhanced localized plasticity (HELP model is the most applicable mechanism ofhydrogen degradation for weldable steels with yield strength up to 1000 MPa.

  9. Steel castings Ultrasonic examination, Part 2: Steel castings for highly stressed components

    CERN Document Server

    International Organization for Standardization. Geneva

    2004-01-01

    This European Standard specifies the requirements for the ultrasonic examination of steel castings (with ferritic structure) for highly stressed components and the methods for determining internal discontinuities by the pulse echo technique. This European Standard applies to the ultrasonic examination of steel castings which have usually received a grain refining heat treatment and which have wall thicknesses up to and including 600 mm. For greater wall thicknesses, special agreements apply with respect to test procedure and recording levels. This European Standard does not apply to austenitic steels and joint welds.

  10. Designing of the chemical composition of steels basing on the hardenability of constructional steels

    International Nuclear Information System (INIS)

    The paper presents the original method of modelling of the relationships between chemical composition of alloy constructional steel and its hardenability, employing neural networks. Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. (author)

  11. Experimental and Theoretical Investigations of Hot Isostatically Pressed-Produced Stainless Steel/High Alloy Tool Steel Compound Materials

    Science.gov (United States)

    Lindwall, Greta; Flyg, Jesper; Frisk, Karin; Sandberg, Odd

    2011-05-01

    Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop-electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.

  12. 49 CFR 192.105 - Design formula for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Design formula for steel pipe. 192.105 Section 192... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.105 Design formula for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the...

  13. 49 CFR 192.309 - Repair of steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of steel pipe. 192.309 Section 192.309... Lines and Mains § 192.309 Repair of steel pipe. (a) Each imperfection or damage that impairs the serviceability of a length of steel pipe must be repaired or removed. If a repair is made by grinding,...

  14. 77 FR 67593 - Steel Import Monitoring and Analysis System

    Science.gov (United States)

    2012-11-13

    ... system can be accessed at http://ia.ita.doc.gov/steel/license/SIMA-FR-Notices.html . FOR FURTHER... ``Steel Import Licensing and Surge Monitoring Program'' (67 FR 79845). In Proclamation 7741 of December 4, 2003 (68 FR 68483), the President terminated the steel safeguard measures but directed the Secretary...

  15. Micronutrient availability from steel slag amendment in pine bark substrates

    Science.gov (United States)

    Steel slag is a byproduct of the steel industry that can be used as a liming agent, but also has a high mineral nutrient content. While micronutrients are present in steel slag, it is not known if the mineral form of the micronutrients would render them available for plant uptake. The objective of...

  16. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stainless steel suture. 878.4495 Section 878.4495...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4495 Stainless steel suture. (a) Identification. A stainless steel suture is a needled or unneedled nonabsorbable surgical suture composed of...

  17. 19 CFR 360.101 - Steel import licensing.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Steel import licensing. 360.101 Section 360.101... ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel mill products are subject to the import licensing requirements. These products are listed in Annex...

  18. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Science.gov (United States)

    2010-10-01

    ... published in “Rules for Building and Classing Steel Vessels”, 1981. (c) The steel cover for the aluminum... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  19. 30 CFR 57.7050 - Tool and drill steel racks.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tool and drill steel racks. 57.7050 Section 57... Rotary Jet Piercing Drilling-Surface and Underground § 57.7050 Tool and drill steel racks. Receptacles or racks shall be provided for drill steel and tools stored or carried on drills....

  20. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gold or stainless steel cusp. 872.3350 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made of austenitic alloys or...