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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

    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

    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. 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

    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

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

    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.

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

    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.

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

    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

  7. 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

    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)

  8. Fatigue behaviour of X70 steel in crude oil

    Gajdoš, Lubomír; Šperl, Martin; Bystrianský, J.

    2015-01-01

    Roč. 49, č. 2 (2015), s. 243-246. ISSN 1580-2949 R&D Projects: GA ČR(CZ) GAP105/10/2052; GA TA ČR(CZ) TE02000162 Institutional support: RVO:68378297 Keywords : corrosion fatigue * S-N curve * X70 steel * crude oil * separated water Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.548, year: 2014 http://mit.imt.si/Revija/izvodi/mit152/gajdos.pdf

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

    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.

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

    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...

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

    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.

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

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

    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.

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

    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

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

    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.

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

    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.

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

    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.

  19. Slow strain rate corrosion and fracture characteristics of X-52 and X-70 pipeline steels

    The susceptibility to stress corrosion cracking (SCC) in a NACE solution saturated with H2S, of the X-52 and X-70 steels was studied using slow strain rate tests (SSRT) and electrochemical evaluations. SCC tests were performed in samples which include the longitudinal weld bead of the pipeline steels and were carried out in the NACE solution at both room temperature and 50 deg. C. After failure, the fracture surfaces were observed in a scanning electron microscope (SEM) and the chemical analysis were obtained using X-rays energy dispersive (EDXs) techniques. The specimens tested in air, exhibited a ductile type of failure, and whereas, those tested in the corrosive solution showed a brittle fracture. Specimens tested in the NACE solution saturated with H2S presented high susceptibility to SCC. Corrosion was found to be an important factor in the initiation of some cracks. In addition, the effect of the temperature on the corrosion attack was explored. The susceptibility to SCC was manifested as a decrease in the mechanical properties. Potentiodynamic polarization curves and hydrogen permeation measurements were made. The diffusion of atomic hydrogen was related to this fracture forms. The hydrogen permeation flux increased with the increasing of temperature

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

    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。

  1. 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

    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.

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

    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.

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

    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.

  4. Micro-electrochemical characterization of corrosion of welded X70 pipeline steel in near-neutral pH solution

    Zhang, G.A. [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alta., T2N 1N4 (Canada); Cheng, Y.F. [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alta., T2N 1N4 (Canada)], E-mail: fcheng@ucalgary.ca

    2009-08-15

    The local corrosion behavior of welded X70 pipeline steel in near-neutral pH solution was studied by micro-electrochemical measurements, including scanning vibrating electrode and local electrochemical impedance spectroscopy. The microstructure of the welded steel was observed by optical microscopy and scanning electron microscopy. It is demonstrated that the microstructure of weld metal consists of acicular ferrite and grain boundary ferrite, while that of heat-affected zone is a mixture of acicular ferrite, bainitic ferrite and a few martensite/austenite microconstituents. The microstructure of base steel is typically ferrite and pearlite. Electrochemical corrosion mechanism of welded X70 steel does not experience change upon hydrogen-charging, or stressing, or both. Hydrogen-charging is capable of enhancing the local anodic dissolution of the steel. The resistance of corrosion product layer decreases with hydrogen-charging, and heat-affected zone has the largest dissolution current upon hydrogen-charging. The increase of applied stress enhanced the anodic dissolution of welded X70 steel, especially the heat-affected zone, in near-neutral pH solution. Maximum current is observed in heat-affected zone, and increases with the increase of applied stresses. The total synergistic effect of hydrogen-charging (10 mA/cm{sup 2}) and applied stress (550 MPa) on anodic dissolution of welded X70 steel in near-neutral pH solution is determined to be within the range of 5.7 and 6.5, with a maximum value encountering in heat-affected zone.

  5. Micro-electrochemical characterization of corrosion of welded X70 pipeline steel in near-neutral pH solution

    The local corrosion behavior of welded X70 pipeline steel in near-neutral pH solution was studied by micro-electrochemical measurements, including scanning vibrating electrode and local electrochemical impedance spectroscopy. The microstructure of the welded steel was observed by optical microscopy and scanning electron microscopy. It is demonstrated that the microstructure of weld metal consists of acicular ferrite and grain boundary ferrite, while that of heat-affected zone is a mixture of acicular ferrite, bainitic ferrite and a few martensite/austenite microconstituents. The microstructure of base steel is typically ferrite and pearlite. Electrochemical corrosion mechanism of welded X70 steel does not experience change upon hydrogen-charging, or stressing, or both. Hydrogen-charging is capable of enhancing the local anodic dissolution of the steel. The resistance of corrosion product layer decreases with hydrogen-charging, and heat-affected zone has the largest dissolution current upon hydrogen-charging. The increase of applied stress enhanced the anodic dissolution of welded X70 steel, especially the heat-affected zone, in near-neutral pH solution. Maximum current is observed in heat-affected zone, and increases with the increase of applied stresses. The total synergistic effect of hydrogen-charging (10 mA/cm2) and applied stress (550 MPa) on anodic dissolution of welded X70 steel in near-neutral pH solution is determined to be within the range of 5.7 and 6.5, with a maximum value encountering in heat-affected zone.

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

    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

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

    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.

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

    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

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

    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.

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

    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.

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

    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.

  12. Corrosion behavior of X-70 pipe steel in near-neutral pH solution

    Niu, L.; Cheng, Y. F.

    2007-08-01

    The mechanism of near-neutral pH stress corrosion cracking (SCC) of natural gas pipelines has not been well-established since the first accident was found in the 1980s. In particular, the role of hydrogen in near-neutral pH SCC has remained unknown. In this work, cyclic voltammetry was used to comprehensively investigate the fundamentals of the electrochemical corrosion reactions occurring at the steel/solution interface in diluted, 5% CO 2/N 2-purged, near-neutral pH bicarbonate solutions. It is shown that there is no stable oxide film formed on the steel surface in near-neutral pH solution. The dissolution-based cracking mechanism does not apply for near-neutral pH SCC of pipelines. The formation of a metastable Fe(OH) 2 deposit layer shows a catalytic activity on hydrogen evolution reaction, indicating that a significant amount of hydrogen could be generated under near-neutral pH condition. The presence of corrosive anions in the soil electrolyte enhances both the anodic polarization of the steel and the cathodic hydrogen evolution reaction, resulting in an increased hydrogen evolution rate. The introduction of oxygen could form a stable oxide film on the surface of steel, resulting in the loss of the surface catalytic effect on hydrogen evolution reaction. Thus, a hydrogen-based mechanism does not apply for SCC in the presence of oxygen.

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

    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.

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

    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

  15. 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

    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)

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

    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

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

    Al Shahrani, Abdullah, E-mail: amfa065@uowmail.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Yazdipour, Nima; Dehghan-Manshadi, Ali [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Gazder, Azdiar A. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2519 (Australia); Cayron, Cyril [CEA, DRT, LITEN, Minatec, 38054 Grenoble Cedex 9 (France); Pereloma, Elena V. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2519 (Australia)

    2013-05-15

    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{sup −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.

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

    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.

  19. Stress corrosion cracking of X70 pipeline steel in near-neutral pH soil solution

    Fang, B.Y.; Wang, J.Q.; Han, E.H.; Zhu, Z.Y.; Ke, W. [Chinese Academy of Sciences, Shenyang (China). State Key Laboratory for Corrosion and Protection, Inst. of Metal Research

    2004-07-01

    Near-neutral pH stress corrosion cracking (SCC) is characterized by wide transgranular cracks with quasi-cleavage on the fracture surface, and there is usually little evidence of general or lateral corrosion. Near-neutral pH SCC is related to dissolution and hydrogen ingress into steel pipes because discharged atomic hydrogen can enter the steel so that cracks are initiated or grown by a combination of dissolution and hydrogen-embrittlement. In this study, the SCC cracking behaviour of an X70 pipeline was investigated using slow strain rate tests (SSRT) and cyclic loading at high R and low frequency in a near-neutral pH soil solution saturated with 5 per cent carbon dioxide (CO{sub 2}) and 95 per cent nitrogen (N{sub 2}). Potentiodynamic polarization analyses and electrochemical impedance spectrum (EIS) analyses were also conducted in order to examine the effect of the concentration of bicarbonate, bubbled gas and the addition of chloride ions on polarization behaviour. Results of the SSRT tests showed that transgranular SCC occurred in the soil solution. Crack initiation was associated with pitting. The pipe's susceptibility to SCC increased with decreases in applied electrochemical potential and strain rate. Cyclic loading tests showed that crack propagation processes were dominated by SCC. At high R and low frequencies, SCC was observed on fatigued, pre-cracked specimens. Results of the electrochemical tests showed that polarization behaviours were influenced by the concentrations of bicarbonate, bubbled gas, and the addition of chloride ions. It was concluded that the addition of chloride ion can influence film stability on pipeline specimen surfaces. 22 refs., 2 tabs., 8 figs.

  20. Effects of corrosion product deposit on the subsequent cathodic and anodic reactions of X-70 steel in near-neutral pH solution

    Meng, G.Z. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4 (Canada); College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhang, C. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4 (Canada); Center of Corrosion and Protection, University of Science and Technology Beijing, Beijing 100083 (China); Cheng, Y.F. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4 (Canada)], E-mail: fcheng@ucalgary.ca

    2008-11-15

    The effects of corrosion product deposit on the subsequent anodic and cathodic reactions of X-70 steel in a near-neutral pH solution were investigated by localized electrochemical impedance spectroscopy (LEIS), scanning vibrating micro-electrode (SVME) and macroscopic EIS measurements as well as surface analysis technique. It is found that the deposit layer formed on the steel surface is porous, non-compact in nature. The presence of a corrosion product layer would enhance adsorption, but significantly inhibit absorption and permeation of hydrogen atoms into steel. It is due to the porous structure of the deposit that generates a spatial separation of cathodic and anodic reaction sites, resulting in an increased effective surface area for hydrogen adsorption and, simultaneously, a 'blocking' effect on hydrogen absorption and permeation. The deposit enhances greatly anodic dissolution of the steel, which is attributed to the adsorption of the intermediate species and the resultant 'self-catalytic' mechanism for corrosion of the steel in near-neutral pH solution. In the presence of corrosion product deposit on the pipeline steel surface, pipeline corrosion, especially pitting corrosion, is expected to be enhanced. Stress corrosion cracks could initiate from the corrosion pits that form under deposit. However, deposit does not contribute to hydrogen permeation, although the hydrogen evolution is enhanced.

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

    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.

  2. Effect of Strain Rate on Cathodic Reaction During Stress Corrosion Cracking of X70 Pipeline Steel in a Near-Neutral pH Solution

    Liu, Z. Y.; Li, X. G.; Cheng, Y. F.

    2011-10-01

    The effect of strain rate on cathodic reactions of X70 pipeline steel during stress corrosion cracking in a near-neutral pH solution was investigated by electrochemical impedance spectroscope and potentiodynamic polarization curve measurements as well as slow strain rate tests. A local additional potential model was used to understand mechanistically the role of strain rate in electrochemical cathodic reaction. It was found that an application of elastic stress would not affect the electrochemical stable state of the steel specimen at a macroscopic scale. Under a weak cathodic polarization, the interfacial charge-transfer process occurring on steel contains both cathodic and anodic reactions. Since the anodic reaction process is still significant, localized dissolution could occur even at such a cathodic potential, resulting in generation of corrosion pits. These pits could be the start sites to initiate stress corrosion cracks. Strain rate affects the corrosion reaction, which is associated with the generation of dislocation emergence points and slip steps on the specimen surface, resulting in a negative local additional potential to enhance the cathodic reaction locally.

  3. Fragilización por Hidrógeno de los Aceros API 5L X60 y API 5L X80 Hydrogen Embrittlement of API 5L X60 and API 5L X80 Steels

    Bruno A Araújo

    2011-01-01

    Full Text Available Se ha determinado el comportamiento mecánico de los aceros API 5L grados X60 y X80, fragilizados por hidrógeno ambiental y por hidrógeno interno. El potencial y la densidad de corriente para la generación del hidrógeno fueron determinados por polarización potenciodinámica, y el tiempo de saturación estimado a partir de datos de difusividad y solubilidad obtenidos en ensayos de permeación con una célula electroquímica. La carga de hidrógeno para reproducir las condiciones de la fragilización por hidrógeno ambiental y fragilización por hidrógeno interno fue realizada generando un gradiente de concentración para el primer caso, y generando gradientes de concentración y de tensiones para el segundo. Luego de los ensayos de tracción se verificò que, en las condiciones definidas en este trabajo, el modo de fractura en ambos tipos de fragilización fue predominantemente dúctil. Ademàs, los dos aceros mostraron una susceptibilidad baja o moderada a la fragilización por hidrógeno ambiental, no siendo susceptibles a la fragilización por hidrógeno interno.The mechanical behavior of the API 5L X60 and X80 grade steels under environmental hydrogen embrittlement effect and internal hydrogen embrittlement effect was determined. The potential and current density for hydrogen generation were determined by potentiodynamic polarization. The saturation time was estimated from diffusivity and solubility data, obtained from permeation tests with an electrochemical cell. The hydrogen charge to reproduce the conditions of the environmental hydrogen embrittlement and the internal hydrogen embrittlement was performed by generating a concentration gradient in the first case, and a concentration and stress gradients in the second case. After the tensile tests it was verified that in the defined tests conditions, the fracture mode in both types of embrittlement was predominantly ductile. Also, both steels showed low or moderate susceptibility to

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

    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.

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

    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

  6. The Effect of Chemical Composition on Microstructure and Properties of Intercritically Reheated Coarse-Grained Heat-Affected Zone in X70 Steels

    Zhu, Zhixiong; Kuzmikova, Lenka; Li, Huijun; Barbaro, Frank

    2013-12-01

    The current study investigates the effect of different levels of Ti, N, and Ti/N ratios on microstructure and properties in the intercritically reheated coarse-grained heat-affected zone (ICCGHAZ) of two-pass submerged arc welds in API 5L grade X70 pipe. Gleeble simulation was employed to reproduce the ICCGHAZ of actual welds. Hardness and Charpy V-notch (CVN) tests were performed on the simulated samples. The microstructure of simulated ICCGHAZ was characterized by optical microscopy and scanning electron microscopy (SEM). LePera color etching technique was employed to identify and quantify the martensitic-austenitic (M-A) constituent. Results show that the simulated ICCGHAZ exhibited extremely low toughness, but in the studied range of Ti and N, there was no correlation with Ti/N ratio. The beneficial effect of near-stoichiometric Ti/N ratio observed in coarse-grained heat-affected zone (CGHAZ) did not translate to ICCGHAZ. This was because of the negative effect of the blocky M-A constituent formed on prior austenite grain boundaries.

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

    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...

  8. Fragilización por Hidrógeno de los Aceros API 5L X60 y API 5L X80 Hydrogen Embrittlement of API 5L X60 and API 5L X80 Steels

    Bruno A Araújo; Jorge A Palma; Vilar, Eudésio O.; Silva, Antonio A.

    2011-01-01

    Se ha determinado el comportamiento mecánico de los aceros API 5L grados X60 y X80, fragilizados por hidrógeno ambiental y por hidrógeno interno. El potencial y la densidad de corriente para la generación del hidrógeno fueron determinados por polarización potenciodinámica, y el tiempo de saturación estimado a partir de datos de difusividad y solubilidad obtenidos en ensayos de permeación con una célula electroquímica. La carga de hidrógeno para reproducir las condiciones de la fragilización p...

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

    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.

  10. Corrosive effect of oil's accompanying water polluted with H2S over steel (API 5L X-52)

    The corrosion from the steel to the carbon in the sale oil pipage conduction, is a serious problem, due to the material and economical looses they cause, damaging even in some cases the productive field. The purpose of this study is to determine the aggressiveness of the oil's water layer, polluted with H2S(g) , over the steel of pipelines' construction (API 5L X-52), taking into account the temperature variations which take place during the transportation of the oil, using the electrochemical techniques of polarisation resistance (LPR) and electrochemical noise. It is pretended to determine the velocity of steel corrosion in the oil's water layer polluted with H2S through electrochemical techniques. It was shown that the temperature increases and the concentration of H2S to 500 ppm in the oil's accompanying water emphasizes the corrosion phenomenon experienced by the steel (9, 188 0 mm/year to 70℃).The results of the electrochemical noise spectrums and the values of the localisation ?s index calculated, shown the presence of corrosion on the steel surface (API 5L X-52).This result was complemented through optic Microscopy which permits to corroborate the poor adherence of the sulphur layers deposited on the metal that increase the appearance of events found with the temperature increase and the concentration of H2S in the environment studied

  11. 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

    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.

  12. Mechanistic investigation of hydrogen-enhanced anodic dissolution of X-70 pipe steel and its implication on near-neutral pH SCC of pipelines

    Li, M.C. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Institute of Materials, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Cheng, Y.F. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    2007-11-01

    The effects of hydrogen-charging on anodic dissolution of pipe steel under near-neutral pH condition were studied by electrochemical techniques. Hydrogen-charging enhances the anodic dissolution rate of the steel. The hydrogen-enhanced dissolution increases with increasing charging current density. The hydrogen effect is attributed to the alteration of chemical potential and exchange current density of steel. Hydrogen-charging affects the corrosion process of the steel. In particular, at a high charging current density, a layer of corrosion product forms on the electrode surface to change corrosion potential and interfacial double-charge layer capacitance as well as charge-transfer resistance. The hydrogen effect factor for enhanced anodic dissolution of steel at an anodic potential of -0.4 V (SCE) is 1.53 only. Hydrogen-enhanced anodic dissolution of steel by itself may not be the major factor contributing to the high rate of crack growth in pipe steel in near-neutral pH electrolyte. A further investigation of the synergistic effect of hydrogen and stress on dissolution at the crack-tip is essential to determine the mechanism of near-neutral pH stress corrosion cracking of pipelines. (author)

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

    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...

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

    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.

  15. Corrosion behavior of API 5L-X80 Pipeline steel for natural gas pipeline

    Natural energy problem, including the environmental aspects had changes into certain circumstances in recent years and natural gas has been a focus of constant attention from the viewpoint of energy efficiency and pollution free. From that kind of background, pipeline construction for petroleum and natural gas were considerate as energy infrastructure maintenance plan. Based on the clarification of Asian Pipeline Project (1997-2007) centered in Japan, international pipeline is needed as the natural gas is mainly transported from gas field in Russia and Middle East to consumer country such as Japan etc. It used in severe condition such as cold district and sea. In the meantime, pipeline steel is not just received damages by earth crust fluctuation and corrosion, but also suffered from the corrosion caused by anions that were dissolved in sea and groundwater. The diversification of dispersion and consumption structure of natural gas supply acceptance base are seen regarding, that made the needs of the storing are rising and dealt with the quantitative spatial expansion of the demand. By that, corrosion resistance, not only the hardness, tough, weldability, corrosiveness gas environment is extremely required. (author)

  16. Hydrogen embrittlement in subsea pipelines made from X70: Effect of plastic deformation on hydrogen diffusion

    Hauge, Anders Senumstad

    2011-01-01

    As a part of the DEEPIT project at SINTEF, hydrogen permeation tests have been carried out on API X70 pipeline steel. The effect of plastic deformationon hydrogen diffusion properties has been evaluated, using a worldwide unique permeation apparatus at NTNU. The apparatus is a purposebuild advanced version the standard hydrogen cell presented by Devanathan and Stachurski [1] in 1962.API X70 steel has been tested both in base metal (BM) and simulated heat affected zone (HAZ) conditions. The he...

  17. 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

    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)

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

    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.

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

    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.

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

    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.

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

    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.

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

    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...

  3. 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

    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

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

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

    2011-07-01

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

  5. Corrosion Study of Steel API 5A, 5L and AISI 1080, 1020 in Drill-Mud Environment of Iranian Hydrocarbon Fields

    Farzam, M.; Baghery, P.; Mardan Dezfully, H. R.

    2011-01-01

    API 5A and 5L (grades J55, H40, N80, and K55) are used in making drill pipe and well casing. In this paper after studying the rheological and chemical properties of the mud, the effective corrosion parameters were reviewed and studied. The drill pipe corrosion management, with reference to NACE PRO 502-2002 was made and showed that for 50 drilling rigs 120 million dollars is to be spent in 21 years for corrosion damage. Potentiodynamic polarization tests were made to study the drill-pipe (API...

  6. 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

    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)

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

    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.

  8. 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

    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

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

    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.

  10. 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

    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.

  11. 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

    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

  12. 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

    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 ...

  13. Hydrogen embrittlement susceptibility of a weld simulated X70 heat affected zone under H2 pressure

    The present paper deals with hydrogen embrittlement (HE) susceptibility of a weld thermal simulated heat affected zone of X70 structural steel in high pressure hydrogen gas at 20 °C. Fracture mechanics Single Edge Notched Tension tests at various hydrogen pressures (0.1, 0.6, 10 and 40 MPa H2) have been carried out. The HE susceptibility was quantified through the measurement of the fracture toughness KQ and J (the effect of hydrogen pressure was addressed through linear load increase conditions till failure was obtained). The results show that hydrogen causes a strong decrease in the fracture toughness with increasing hydrogen pressure. The critical hydrogen pressure for the onset of HE was observed to fall between 0.1 MPa and 0.6 MPa. These results were supported by Scanning Electron Microscope (SEM) investigations of the fracture surfaces which showed a clear shift in the fracture mode at 0.6 MPa H2. Moreover, constant load tests were carried out in order to investigate the influence of hydrogen exposure time. The results imply that fracture always occurs within 8 h and that longer time to failure is related to stronger toughness reduction. This effect is more pronounced for test at 40 MPa than at 0.6 MPa hydrogen pressure levels. 3D Finite Element calculations of hydrogen diffusion have been performed and the results are discussed in relation to the experiments, in order to attempt to identify the hydrogen populations (diffusible or trapped) which act predominantly on the embrittlement of the material

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

    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.

  15. Steel

    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

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

    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

  17. 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

    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.

  18. 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)

    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。

  19. 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

    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.

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

    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

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

    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.

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

    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...

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

    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 measure...

  4. Expression of CDC5L is associated with tumor progression in gliomas.

    Chen, Wenjuan; Zhang, Li; Wang, Yan; Sun, Jie; Wang, Donglin; Fan, Shaochen; Ban, Na; Zhu, Junya; Ji, Bin; Wang, Yuchan

    2016-03-01

    Cell division cycle 5-like (CDC5L) protein is a cell cycle regulator of the G2/M transition and has been reported to participate in the catalytic step of pre-messenger RNA (mRNA) splicing and DNA damage repair. Recently, it was also found to act as a candidate oncogene in osteosarcoma and cervical tumors. However, the role of CDC5L expression in tumor biology was still unclear. Here, we analyzed the expression and clinical significance of CDC5L in gliomas. The expression of CDC5L in fresh glioma tissues and paraffin-embedded slices was evaluated by western blot and immunohistochemistry, respectively. We found that CDC5L was highly expressed in glioma tissues. The expression of CDC5L was significantly associated with glioma pathology grade and Ki-67 expression. Univariate and multivariate analyses showed that high CDC5L expression was an independent prognostic factor for glioma patients' survival. To determine whether CDC5L could regulate the proliferation of glioma cells, we transfected glioma cells with interfering RNA target CDC5L, then investigated cell proliferation with cell counting kit (CCK)-8, flow cytometry assays and colony formation analyses. Our results indicated that knockdown of CDC5L would inhibit proliferation of glioma cells. Besides, reduced expression of CDC5L could induce the apoptosis of glioma cells. These findings suggested that CDC5L might play an important role in glioma and thus be a promising therapeutic target of glioma. PMID:26490980

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

    Réquiz, R.; Camero, S.; Aristizabal, V.; A. Rivas

    2008-01-01

    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. Theref...

  6. 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

    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.

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

    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.

  8. 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

    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

  9. 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

    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.

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

    Mawson, John A.; Charles S. Brennan; Kelvin K. T. Goh; Lara Matia-Merino; Oni Yuliarti

    2011-01-01

    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 (M w) pe...

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

    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

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

    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

  13. Corrosion behavior of novel 3%Cr pipeline steel in CO2 Top-of-Line Corrosion environment

    Highlights: ► CO2 Top-of-Line Corrosion environment in wet gas pipelines was simulated. ► Compared with X70, the resistance to CO2 TLC of novel 3%Cr pipeline steel is better. ► The effect of Cr enrichment in the corrosion scale on CO2 TLC is confirmed. -- Abstract: CO2 Top-of-Line Corrosion (TLC) of carbon steel pipelines is a serious problem for wet gas transportation. We have studied the corrosion behavior of novel 3%Cr (3Cr) pipeline steel and conventional carbon steel (X70) in the simulated CO2 TLC environment. The composition and morphology of the corrosion scale are characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscopy analyses. The results indicate that 3Cr pipeline steel shows superior resistance to CO2 TLC, exhibiting uniform corrosion with duplex corrosion layer, while X70 suffers severe localized corrosion. It was suggested that the inner Cr enriched layer enhanced the protective ability of the scale to steel substrate and improved the resistance to localized corrosion in CO2 TLC environment.

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

    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

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

    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

  16. Relationship of C5L2 Receptor to Skeletal Muscle Substrate Utilization

    Roy, Christian; Paglialunga, Sabina; Schaart, Gert; Moonen-Kornips, Esther; Meex, Ruth C.; Phielix, Esther; Hoeks, Joris; Hesselink, Matthijs K. C.; Cianflone, Katherine; Schrauwen, Patrick

    2013-01-01

    Objective To investigate the role of Acylation Stimulating Protein (ASP) receptor C5L2 in skeletal muscle fatty acid accumulation and metabolism as well as insulin sensitivity in both mice and human models of diet-induced insulin resistance. Design and Methods Male wildtype (WT) and C5L2 knockout (KO) mice were fed a low (LFD) or a high (HFD) fat diet for 10 weeks. Intramyocellular lipid (IMCL) accumulation (by oil red O staining) and beta-oxidation HADH enzyme activity were determined in ske...

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

    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

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

    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.

  19. The variation in cooling rate in a 35 mm thick steel block using different cooling media

    The objectives of this study were to determine and compare cooling rates of a 70 x 70 x 35 mm steel block during: (i) air cooling; (ii) water quenching; (iii) oil quenching and then to decide on a means of producing a cooling rate of approximately 50 deg C/min and examine the variation of the cooling rate through the thickness of the specimen blank. Experimental details are given. Results are reported and discussed. (author)

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

    Yuliarti, Oni; Matia-Merino, Lara; Goh, Kelvin K. T.; Mawson, John A.; Brennan, Charles S.

    2011-01-01

    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. PMID:22072895

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

    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.

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

    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

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

    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...

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

    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. PMID:26428122

  5. 3.5L V6 EcoBoost - democratization of sustainable engine technology

    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.)

  6. Steel Planning

    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

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

    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.

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

    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

  9. Alloyed steel

    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.)

  10. Tool steels

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... 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...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  11. Steel welding.

    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....

  12. A new generation of ultra high strength steel pipelines

    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)

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

    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.

  14. 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

    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.

  15. Effect of orbital automatic welding on the weld metal mechanical properties in API 5L X65 natural gas transmission pipe

    Baek, J.-H.; Kim, Y.-P.; Kim, W.-S. [Korea Gas Corp., Ansan (Korea, Republic of)

    2000-07-01

    Most natural gas transmission pipelines in Korea have been constructed using a manual welding processes but major gas companies are looking into the advantages of an automatic process for girth welding. The automatic welding process is divided into gas tungsten arc welding (GTAW) and gas-metal-arc welding (GMAW) processes. GTAW uses an inert gas such as argon to shield weld metal from the atmosphere during welding and a 0.9-1.6 mm solid wire. Filler metals used in the GMAW process are classified into solid wire and flux cored wire. In this study, Charpy impact tests, crack tip opening tests and micro-hardness tests were conducted on a steel pipeline to determine the effects of weld metal composition and microstructure on the toughness of weld metal. API 5L X65 steel pipes with 17.5 mm wall thickness and 762 mm outer diameter were welded using an orbital automatic welding process. Flux cored arc welding (FCAW) and GTAW were used to evaluate the automatic welding process. Manual welds were done using GTAW with ER70S-G filler metal for the root pass and shielded metal arc welding with low hydrogen E9016-G electrode for the remaining passes. It was concluded that the filler metals with the highest fracture toughness were E80T1-K2 and E71T-1 using the FCAW process and ER80S-G using the GTAW process. The filler metals with the correct hardness were E800T1-K2 and E71T-1 using the FCAW process. 13 refs., 3 tabs., 4 figs.

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

    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.

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

    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.

  18. Inhibiting evaluation of β-Cyclodextrin-modified acrylamide polymer on alloy steel in sulfuric solution

    Highlights: • β-Cyclodextrin-modified acrylamide polymer is a mixed inhibitor for X70 in H2SO4. • Inhibition efficiency increases with the increasing of inhibitor concentration. • The polymer inhibitor is effective even at higher temperature. • EIS and polarization results are in good agreement. • The adsorption of polymer on metal surface obeys the Langmuir isotherm. - Abstract: The inhibiting performance of β-Cyclodetrin-modified acrylamide polymer (poly(AM-co-A-β-CD-co-NaAA)) on X70 steel in 0.5 M H2SO4 solution has been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The polarization curves results reveal that polymer acts as a mixed-type inhibitor. The inhibition efficiency is found to increase by increasing the polymer concentration up to maximum 84.9% for 150 mg L−1 at 303 K. The adsorption is confirmed to obey the Langmuir isotherm. The SEM and EDS results demonstrate that X70 surface is protected by β-Cyclodextrin-modified acrylamide polymer

  19. Hegelian Steel

    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....

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

    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...

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

    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.

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

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

    2016-05-01

    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.

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

    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

  4. 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

    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.

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

    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

  6. Ford's new 3.5 l V6 gasoline engine. Downsizing with 'EcoBoost'; Der neue 3,5-l-V6-Ottomotor von Ford. Downsizing durch 'EcoBoost'

    Schmidt, Gerhard; Kapp, Daniel; Schamel, Andreas; Hinds, Brett; Weaver, Corey [Ford Motor Company, Dearborn, MI (United States)

    2009-03-15

    Ford banded a new motor technology as 'EcoBoost'. It applies direct fuel injection and turbocharging to gasoline engines and provides a major improvement in fuel economy via engine downsizing, combined with improved performance. The first Ford engine with this technology is the 3.5 l V6 EcoBoost in the 2010 Lincoln MKS luxury sedan. Combustion, fuel, boost, and power conversion systems are discussed in detail with emphasis on the efficiency and value of these systems. Engine level fuel economy and performance are discussed, and compared to conventional gasoline engines. (orig.)

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

    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.

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

    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)

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

    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.

  10. Tritium retention on stainless steel surface exposed to plasmas in LHD

    Tritium retention of samples exposed to plasmas in the Large Helical Device (LHD) during each campaign in 12th, 13th and 14th cycles has been studied. Small sample plates made of stainless steel type 316L were fixed in advance at four different walls in LHD: location of a sample plate was 1.5U, 5.5U, 6.5L and 9.5L. After plasma exposure in each cycle, these samples were exposed to tritium gas at a temperature of 300 or 623 K. Retention behavior of tritium in surface layers of each sample was mainly examined using β-ray-induced X-ray spectrometry (BIXS) and X-ray photoelectron spectroscopy (XPS). The energy spectra observed by BIXS and XPS showed the depositions of boron, carbon, titanium, chromium, iron, nickel and molybdenum with oxygen. Tritium retention of the samples exposed to plasma increased than that of a bare SS316L sample, although it was largely different in the location of a sample. When the samples were exposed to tritium gas at 300 K, the order of magnitude of tritium retention was as follows: 9.5L>>5.5U>6.5L>1.5U for 12th cycle, 6.5L>9.5>1.5U>5.5U for 13th cycle, and 6.5L>1.5U∼5.5U>9.5L for 14th cycle. (author)

  11. The new Nissan FF Hybrid + new 4-cylinder 2.5L supercharged engine. A new approach to powersource evolution

    Minakawa, Shunichi; Onoyama, Taiichi; Ishizuka, Takashi [Nissan Motor Co., Ltd., Kanagawa (Japan)

    2013-08-01

    In 2013, Nissan is going to launch a technology combination of 1-Motor 2-Clutch Parallel Hybrid system and 4-cylinder 2.5L supercharged engine for Infiniti QX60 HYBRID and new Nissan Pathfinder HYBRID. This Hybrid system has been developed to have three key advantages: (1) Significant improvement in fuel economy even when Highway driving, (2) Better response and more direct feeling, (3) Lightweight system and low-cost. To achieve these objectives, Nissan fitted a 1-Motor 2-Clutch Parallel system onto a new generation CVT without Torque Converter, combined with downsized 4 cylinder 2.5L supercharged Engine, which provides better fuel economy and V6 3.5-liter class driving performance. Nissan has developed the following proprietary technologies to realize the development of this Hybrid system: - High output and compact Li-ion battery, - Innovative high speed and precise motor and clutch control. Additionally, new technologies are added to both Engine and CVT. Engine: New 4-lobes Roots supercharger with precise electrical boost control. CVT: Chain driven, high efficiency and low friction with wide cover ratio. In this paper Nissan will introduce an outline of the system, key breakthrough technologies and how low fuel economy comparable with the compact car class, has been achieved and demonstrated. (orig.)

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

    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...... disease, respiratory disease, depression, diabetes, liver disease, personality disorders, arthritis, and stroke) and a student cohort, completed the 3L and 5L and, for most participants, also dimension-specific rating scales. The 3L and 5L were compared in terms of feasibility (missing values...

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

    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)

  14. Ultrahigh carbon steels, Damascus steels, and superplasticity

    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.

  15. Reactor construction steels

    The basic functions of light water reactor components are shown on the example of a pressurized water reactor and the requirements resulting therefrom for steel, the basic structural material, are derived. A detailed analysis of three main groups of reactor steels is presented and the applications are indicated of low-alloyed steels, high-alloyed austenitic steels, and steels with a high content of Ni and of alloying additions for steam generator pipes. An outline is given of prospective fast breeder reactor steels. (J.K.)

  16. Cross-cultural measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) in patients with type 2 diabetes mellitus in Singapore

    Wang, Ye; Tan, Ngiap-Chuan; Tay, Ee-Guan; Thumboo, Julian; Luo, Nan

    2015-01-01

    Background: This study aimed to assess the measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) among the English, Chinese, and Malay versions. Methods: A convenience sample of patients with type 2 diabetes mellitus were enrolled from a public primary health care institution in Singapore. The survey questionnaire comprised the EQ-5D-5L and questions assessing participants’ socio-demographic and clinical characteristics. Multiple linear regression models were used to assess the difference i...

  17. 77 FR 56809 - Certain Small Diameter Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From...

    2012-09-14

    ..., seamless pipes are seamless carbon and alloy (other than stainless) steel pipes, of circular cross-section... produced in non- standard wall thicknesses are commonly referred to as tubes. The seamless pipes subject to.... Seamless line pipes are produced to the API 5L specification. Seamless pipes are commonly produced...

  18. 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

    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.

  19. Studi Laju Korosi dan Surface Morfologi Pipa Bawah Laut API 5L Grade X65 dengan Variasi Sudut Bending

    Apri Malani Putri

    2012-09-01

    Full Text Available Proses bending banyak digunakan dalam proses produksi pada pipa. Proses ini akan menghasilkan peristiwa tensile dan compress, maka stress yang terjadi akibat gaya tekan atau gaya tarik ini akan bekerja simultan pada lingkungan korosif yang dapat menyebabkan terjadinya korosi. Deformasi yang terjadi ini akan mengakibatkan perbedaan tingkat laju korosi pada setiap perubahannya, yaitu dengan sudut bending yang berbeda. Oleh karena itu, untuk membuktikannya dilakukanlah penelitian dengan tiga sudut bending yang berbeda yaitu 60°, 90°, dan 135°. Material yang digunakan adalah pipa bawah laut API 5L Grade X65. Pipa ini dibending dengan sudut di atas, kemudian dipotong tiga spesimen pada setiap intrados dan ektsrados pipa untuk setiap sudut bending. Pengujian laju korosi dengan menggunakan sel tiga elektroda dengan campuran larutan FeCl3 dan 0,3% aquades. Dari hasil penelitian diperoleh nilai laju korosi untuk intrados bending pipa ; sudut bending 60° adalah 0,75 mm/year, sudut 90° adalah 0,64 mm/year, dan untuk sudut 135° adalah 0,43 mm/year. Sedangkan untuk ekstrados pipa; sudut 60° nilai laju korosinya adalah 0,59 mm/year, sudut 90° adalah 0,49 mm/year, dan untuk sudut bending 135° nilai laju korosinya adalah 0,4 mm/year. Analisa surface morfologi yang dilakukan pada spesimen menyimpulkan bahwa semakin tinggi nilai laju korosi, maka bentuk permukaan dari spesimen akan semakin kasar,begitupun sebaliknya

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

    HÜSEYİN UZUN

    2002-01-01

    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, kırı...

  1. Effect of the heat-affected zones on hydrogen permeation and embrittlement of low-carbon steels

    Steels with yield strengths below about 900 MPa are essentially immune to hydrogen embrittlement, and almost all pipeline steels have a yield strength below that value. However, same catastrophic failures of pipelines have been reported. Under mechanical stress these failures are due to the local formation of high-hardness martensite (hard spot) during cooling and from the presence of absorbed hydrogen developed under cathodic over-protection. This paper describes a photoelectrochemical, micrographic and fractographic study of the effect of an heat-affected zone (hard spot) on hydrogen permeation and the embrittlement of an API 5L STD X60 steel. (orig.)

  2. Weldability of Stainless Steels

    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.)

  3. A Comparative Study on the Electrochemical Corrosion Behavior of Iron and X-65 Steel in 4.0 wt % Sodium Chloride Solution after Different Exposure Intervals

    El-Sayed M. Sherif

    2014-07-01

    Full Text Available In this work, the results obtained from studying the anodic dissolution of pure iron and API X-65 5L pipeline steel after 40 min and 12 h exposure period in 4.0 wt % NaCl solutions at room temperature were reported. Potential-time, electrochemical impedance spectroscopy, potentiodynamic polarization, and chronoamperometric current-time at constant potential techniques were employed. It has been found that the iron electrode corrodes in the chloride test solutions faster than the API X-65 5L steel does under the same conditions. Increasing the exposure period for the electrodes from 40 min to 12 h showed a significant reduction in the corrosion parameters for both iron and steel in the 4.0 wt % NaCl solution. Results together confirmed clearly that the X-65 steel is superior to iron against corrosion in sodium chloride solutions.

  4. Welding irradiated stainless steel

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials

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

    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 ...

  6. Nitrogen-alloyed martensitic steels

    A report is presented on initial results with pressure-nitrided martensitic steels. In heat-resistant steels, thermal stability and toughness are raised by nitrogen. In cold work steel, there is a more favourable corrosion behaviour. (orig./MM)

  7. Characterization of fiber laser welds in X100 pipeline steel

    Recent developments in steel grades for pipeline applications have lead to new high strength grades, such as API5L-X100. Higher strength enables the use of thinner walled pipe, with greater operating pressures and reduced overall costs. The base material presents good toughness values; however there are still limitations regarding the weldability of this material. Research is needed to develop appropriate welding procedures, avoiding typical problems like: cold cracking and toughness reduction in the weld area, and to achieve high productivity and economical feasibility. In the present paper an X100 steel grade welded by high power fiber lasers and TIG is studied and the microstructures developed are analysed aiming to contribute to a better understanding of the transformations induced in this material by the thermal cycle associated with fusion welding.

  8. 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

    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

  9. Manganese in sintered steels

    Based on the review of papers the results of the investigations of sintered manganese steels are presented. The effect of additional alloying elements such as copper, molybdenum and silicon on dimensional changes, density, tensile strength, hardness and elongation of such steels are also reported. (author)

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

    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.

  11. Nuclear transmutation in steels

    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.

  12. Analisa Pengaruh Jenis Elektroda terhadap Laju Korosi pada Pengelasan Pipa API 5L Grade X65 dengan Media Korosi FeCl3

    Gita Anggaretno; Imam Rochani; Heri Supomo

    2012-01-01

    Submarine pipelines (pipa bawah laut) di desain untuk transportasi minyak, gas atau air dari lepas pantai menuju receiving point. Baja API 5L Grade X65 merupakan jenis pipa baja yang banyak digunakan pada pipa penyalur gas, air, dan minyak pada pipa bawah laut. Sistem perpipaan ini tidak mungkin terbentuk tanpa adanya proses las. Pengelasan Flux Cored Arc Welding (FCAW)  merupakan las yang umum digunakan dalam struktur anjungan lepas pantai. Penelitian ini bertujuan untuk mengetahui pengaruh ...

  13. BORONIZING OF STEEL

    Arzum ULUKÖY

    2006-02-01

    Full Text Available Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specifications and the factors that effect boride layer are examined

  14. Glass Stronger than Steel

    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.

  15. Life after Steel

    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…

  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

    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. Articles comprising ferritic stainless steels

    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.

  18. The candidate genes TAF5L, TCF7, PDCD1, IL6 and ICAM1 cannot be excluded from having effects in type 1 diabetes

    Vella Adrian

    2007-11-01

    Full Text Available Abstract Background As genes associated with immune-mediated diseases have an increased prior probability of being associated with other immune-mediated diseases, we tested three such genes, IL23R, IRF5 and CD40, for an association with type 1 diabetes. In addition, we tested seven genes, TAF5L, PDCD1, TCF7, IL12B, IL6, ICAM1 and TBX21, with published marginal or inconsistent evidence of an association with type 1 diabetes. Methods We genotyped reported polymorphisms of the ten genes, nonsynonymous SNPs (nsSNPs and, for the IL12B and IL6 regions, tag SNPs in up to 7,888 case, 8,858 control and 3,142 parent-child trio samples. In addition, we analysed data from the Wellcome Trust Case Control Consortium genome-wide association study to determine whether there was any further evidence of an association in each gene region. Results We found some evidence of associations between type 1 diabetes and TAF5L, PDCD1, TCF7 and IL6 (ORs = 1.05 – 1.13; P = 0.0291 – 4.16 × 10-4. No evidence of an association was obtained for IL12B, IRF5, IL23R, ICAM1, TBX21 and CD40, although there was some evidence of an association (OR = 1.10; P = 0.0257 from the genome-wide association study for the ICAM1 region. Conclusion We failed to exclude the possibility of some effect in type 1 diabetes for TAF5L, PDCD1, TCF7, IL6 and ICAM1. Additional studies, of these and other candidate genes, employing much larger sample sizes and analysis of additional polymorphisms in each gene and its flanking region will be required to ascertain their contributions to type 1 diabetes susceptibility.

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

    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...

  20. Thermochemical surface engineering of steels

    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. Continuous steel production and apparatus

    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.

  2. Thermochemical surface engineering of steels

    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...

  3. Analisa Pengaruh Jenis Elektroda terhadap Laju Korosi pada Pengelasan Pipa API 5L Grade X65 dengan Media Korosi FeCl3

    Gita Anggaretno

    2012-09-01

    Full Text Available Submarine pipelines (pipa bawah laut di desain untuk transportasi minyak, gas atau air dari lepas pantai menuju receiving point. Baja API 5L Grade X65 merupakan jenis pipa baja yang banyak digunakan pada pipa penyalur gas, air, dan minyak pada pipa bawah laut. Sistem perpipaan ini tidak mungkin terbentuk tanpa adanya proses las. Pengelasan Flux Cored Arc Welding (FCAW  merupakan las yang umum digunakan dalam struktur anjungan lepas pantai. Penelitian ini bertujuan untuk mengetahui pengaruh dari variasi elektroda pengelasan terhadap laju korosi pada pipa API 5L Grade X65. Variasi elektroda yang digunakan adalah elektroda spesifikasi AWS yaitu E7018, E6010 dan E6013. Metode pengujian korosi ini menggunakan bantuan sel tiga elektroda dengan media korosi FeCl3 yang mengacu pada ASTM G48. Dari pengujian ini didapatkan hasil laju korosi pada pengelasan pipa dengan elektroda E7018 adalah 0,53 mmpy, untuk elektroda E6013 adalah 0,69 mmpy, dan untuk E6010 adalah 0,62 mmpy. Perbedaan laju korosi tersebut dipengaruhi oleh tensile strength pada elektroda dan baja yang di las. Selisih kandungan unsur Mangan (Mn pada pipa dan elektroda las juga mempengaruhi perbedaan laju korosi pada pipa. Berdasarkan hasil foto SEM (Scanning Electron Microscope, secara morfologi permukaan weldmetal dengan nilai laju korosi paling tinggi, permukaanya terlihat lebih kasar. Akan tetapi laju korosi hasil las dengan elektroda-elektroda trsebut masih berada pada level yang diijinkan.

  4. Fatigue damage of steel components

    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...

  5. A-3 steel work completed

    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.

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

    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.

  7. On choice of tempered steels

    For the purpose of developing a graphical method for choosing structural steels, a change in the propagation work of a crack and in the critical temperature of brittleness of 40, 40Kh, 40KhN, and 40KhNM steels, was examined depending on the hardness after hardening and tempering. A diagram enabling to choose the grade of steel for making an article of known dimensions according to the preset values of its mechanical properties has been plotted. The developed selection scheme takes into account the hardenability of steels and the influence of the hardness after thermal treatment on the cold-shortness of steel

  8. High-purity steel making

    The conference heard a total of 32 papers of which 8 were inputted in INIS. These papers are centred on certain topical problems related to the manufacture of high purity steels, on impurities in steels, the effect of the radiation environment on steels made by different melting methods, argon protection against reoxidation during casting, the effects of secondary metallurgy on the properties of stainless austenitic steel, the properties of electroslag remelted steel, the metallurgic quality of the central part of ingots weighing 135 tons, and the chemical heterogeneity of ingots and castings. (J.C.)

  9. Japan steel mill perspective

    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.

  10. Thermomechanical treatment of steel

    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)

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

    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...

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

    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.

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

    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.

  14. High spin, hole delocalization and electron transfer in LBaCo2O5.5 (L = Sm, Eu, Gd, Tb, Dy, Y)

    By means of electron-correlation-corrected density functional calculations for GdBaCoO5.5, it has been found that the pdσ hole delocalization in the 'almost high-spin' state is responsible for the antiferromagnetic-ferromagnetic-like transition and insulator-metal transition in isostructural LBaCo2O5.5 (L = Sm, Eu, Gd, Tb, Dy, Y), and that the simultaneous octahedral Co1 3z2 - r2 /x2 - y2 (pyramidal Co2 x2 - y2) → Co1 (Co2) yz electron transfer gives rise to the lattice anomaly at TIM. The present study, supporting the author's prior work (Wu H 2001 Phys. Rev. B 64 092413), provides a unified explanation for a number of experimental findings for LBaCo2O5.5

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

    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

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

    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.

  17. History of ultrahigh carbon steels

    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.

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

    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.

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

    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...

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

    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.

  1. Steel containment buckling

    The Steel Containment Buckling program is in its fourth phase of work directed at the evaluation of the effects of the structural failure mode of steel containments when the membrane stresses are compressive. The structural failure mode for this state of stress is instability or buckling. The program to date has investigated: (1) the effect on overall buckling capacity of the ASME area replacement method for reinforcing around circular penetrations; (2) a set of benchmark experiments on ring-stiffened shells having reinforced and framed penetrations; (3) large and small scale experiments on knuckle region buckling from internal pressure and post-buckling behavior to failure for vessel heads having torispherical geometries; and (4) buckling under time-dependent loadings (dynamic buckling). The first two investigations are complete, the knuckle buckling experimental efforts are complete with data analysis and reporting in progress, and the dynamic buckling experimental and analytical work is in progress

  2. Reactor pressure vessel steels

    Research and development activities related to reactor pressure vessel steels during 1997 are reported. The objectives of activities of the Belgian Nuclear Research Centre SCK/CEN in this domain are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate a methodology on a broad database; (3) to achieve regulatory acceptance and industrial use

  3. Steels and welding nuclear

    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

  4. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    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...

  5. Contaminated Mexican steel incident

    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

  6. Stainless Steel Permeability

    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.

  7. Fracture Mechanisms in Steel Castings

    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.

  8. PHOSPHORUS REMOVAL USING STEEL SLAG

    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.

  9. Strip casting of stainless steels

    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...

  10. Output Model of Steel Plant

    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.

  11. Fatique behaviour of electrical steel

    Bode B.; Zeismann F.; Brückner-Foit A.

    2014-01-01

    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, ...

  12. Mechanics in Steels through Microscopy

    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...

  13. Synthesis of thermit noncorrodible steels

    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...

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

    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.

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

    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.

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

    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

  17. Pengaruh Variasi Goresan Lapis Lindung Dan Variasi pH Tanah Terhadap Arus Proteksi Sistem Impressed Current Cathodic Protection (ICCP Pada Pipa API 5L Grade B

    Trendy Leo Pratama

    2015-03-01

    Full Text Available Korosi merupakan penyebab utama terjadinya kegagalan material pipeline akibat berinteraksi secara langsung dengan lingkungan. Pemberian lapis lindung yang selama ini menjadi pilihan utama untuk mengontrol korosi tidak selamanya bisa diandalkan. Hal ini disebabkan kemungkinan terjadinya kerusakan lapis lindung selama proses shipping atau instalasi sangatlah besar. Oleh karena itu sering kali pemberian lapis lindung dikolaborasikan dengan perlindungan sistem proteksi katodik, khususnya sistem arus paksa (ICCP. Penelitian ini bertujuan mempelajari pengaruh luas goresan lapis lindung dan pH tanah terhadap arus proteksi sistem proteksi katodik arus paksa (ICCP. Goresan yang diberikan berbentuk lingkaran dan persegi panjang dengan luas 10 mm2, 50 mm2, 100 mm2, 150 mm2, 250 mm2, dan 500 mm2. Spesimen tanpa goresan dan tanpa lapis lindung digunakan sebagai pembanding. Sedangkan untuk variasi pH tanahnya adalah pH 3 (asam, pH 7 (netral, dan pH 11 (basa. Pipa API 5L grade B digunakan sebagai katoda dan grafit sebagai anoda, serta rectifier sebagai penyearah arus (DC. Arus proteksi ICCP diatur hingga mencapai nilai potensial proteksi -850 mV vs elektroda Cu/CuSO4. Setelah dilakukan pengkondisian awal selama 8 hari dan 7 hari pengukuran arus, didapatkan hasil bahwa semakin semakin besar goresan lapis lindung maka semakin besar arus proteksi yang dibutuhkan dalam kondisi pH tanah yang sama. Sedangkan dalam kondisi luas goresan yang sama, kebutuhan arus proteksi meningkat seiring dengan semakin rendahnya pH tanah (semakin asam

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

    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.

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

    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...

  20. Steels for nuclear power. I

    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

  1. Niobium in rail steels

    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

  2. Steel designers' handbook

    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

  3. Mechanics in Steels through Microscopy

    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

  4. Steel structures for nuclear facilities

    The guide presents requirements on the design and manufacturing of steel structures for nuclear facilities as well as on documents to be submitted to Finnish Radiation and Nuclear Safety Authority (STUK). Inspection of steel structures during plant construction and operation is also described

  5. The industrial ecology of steel

    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.

  6. Stainless steels low temperature nitriding

    Nitrogen ions implantation of 316L stainless steel leads to monophasic diffusion layers, which are constituted of a solid solution (γN) fcc, metastable, nitrogen sur-saturated, and without order. This article shows that for 316L stainless steels,these layers improve the tribological properties without degradation of the corrosion resistance. (A.B.). 13 refs. 6 figs

  7. Steels from materials science to structural engineering

    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. 

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

    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. Dual phase bainitic linepipe steels

    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.

  10. 2169 Steel Waveform Experiments

    Furnish, M.; Alexander, C.; Reinhart, W.; Brown, J.

    2013-06-01

    In support of efforts to develop multiscale models of materials, we performed eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn). These experiments provided 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 used, with samples 1 to 5 mm thick. The study focused on dynamic strength determination via the release/reshock paths. Reshock tests with explosively welded impactors produced clean results. 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 allowed release information to be determined from these free surface samples as well. 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. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

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

    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.

  12. 49 CFR 192.55 - Steel pipe.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  13. New structural high strength rationally alloyed steels

    New developments in high strength structural steels are reported. Properties and perspective fields of application are described for the following materials: austenitic chromium steels with ultra equilibrium nitrogen content, steels with nitrogen martensite structure, microalloyed ferritic-pearlitic steels with decreased concentrations of Mn and Ni, high ductility heat resisting steels, nonmagnetic chromium free Mn-Ni-Cu-V-C steels and iron powder alloys with superhard carbon phases. Steel 02Kh12G14N4YuM is recommended to be used for parts and assemblies of nuclear power plants

  14. High-strength, low-alloy steels.

    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

  15. Modelling fracture in ferritic steel

    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.

  16. Stainless steel denitriding with slag

    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

  17. Stainless steel display evaluation

    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.

  18. JPDR vessel steel examination

    There is a need to validate the results of irradiation effects research by the examination of material taken directly from the wall of a pressure vessel which has been irradiated during normal service. This task has been included with the HSSI Program to provide just such an evaluation of material from the wall of the pressure vessel from the JPDR. The JPDR was a small BWR that began operation in 1963. It operated until 1976, accumulating ∼17,000 h of operation, of which a little over 14,000 h were with the original 45-MWTh core, and the remaining fraction, late in life, with an upgraded 90-MWTh core. The pressure vessel of the JPDR, fabricated from A 302, grade B, modified steel with an internal weld overlay cladding of 304 stainless steel, is approximately 2 m ID and 73 mm thick. It was fabricated from two shell halves joined by longitudinal seam welds located 180 degrees from each other. The rolling direction of the shell plates is parallel to the axis of the vessel. It operated at 273 degrees C and reached a maximum fluence of about 2.3 x 1018 n/cm2 (> 1 MeV). The impurity contents in the base metal are 0.10 to 0.11% Cu and 0.010 to 0.017% P with a nickel content of 0.63 to 0.65%. Impurity contents of the weld metal are 0.11 to 0.14% Cu and 0.025 to 0.039% P with a nickel content of 0.59%

  19. 2169 steel waveform experiments.

    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-mm-thick 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.

  20. Envelhecimento por Deformação em Juntas Soldadas de Tubos de Aço API5L X65Q sem Costura

    Rodolfo Lisboa Batalha

    2015-09-01

    Full Text Available Resumo Neste trabalho, investigaram-se efeitos do fenômeno de envelhecimento por deformação em juntas obtidas por soldagem a arco elétrico com proteção gasosa (GMAW, de tubos sem costura de aço API5L X65Q. Corpos de prova (CPs obtidos a partir das juntas soldadas foram submetidos à uma deformação plástica a frio de 3% e posteriormente envelhecidas por 1h a 250°C, de forma a se induzir envelhecimento estático. Buscando avaliar o envelhecimento dinâmico, os CPs foram deformados até 3% e o carregamento foi mantido durante 1h a 250°C. Os CPs envelhecidos foram submetidos a ensaios de tração e amostras representativas foram analisadas ao microscópio óptico e microscópio eletrônico de varredura. Observou-se que o fenômeno modificou a fração volumétrica de constituintes secundários no metal de solda e na ZTA, com aumento na proporção de agregados ferrita-carbonetos. Com relação às propriedades mecânicas, constatou-se que o fenômeno reduziu a razão elástica das juntas soldadas devido a um aumento no limite de resistência, além de aumentar o alongamento total, não prejudicando, portanto, as propriedades mecânicas em tração das juntas soldadas. Ao se comparar o envelhecimento estático com o envelhecimento dinâmico, observou-se que o aumento na capacidade de deformação plástica das juntas soldadas foi maior após envelhecimento estático por deformação.

  1. Some peculiarities of corrosion of wheel steel

    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...

  2. Effects of changes in steel industry concentration

    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 ...

  3. Review on Cold-Formed Steel Connections

    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...

  4. CHANGES IN DISTRIBUTION OF STEEL PRODUCTS

    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...

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

    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.

  6. EVALUATION OF CORROSION IN WELD REGION AND BASE METAL OF API 5L X80 PIPE IN MEDIUM CONTAINING HYDROGEN SULPHIDE

    Bruno Nagle Armendro

    2012-09-01

    Full Text Available The objective of this study is to compare the corrosion resistance of the base metal (MB and weld region (RCS of a X80 pipeline in three types of aqueous solution of acetic acid (CH3COOH 0,5% by weight: naturally aerated, non-aerated and non-aerated with H2S. Linear polarization is employed for it determinates Polarization Resistance (Rp which allows comparing the corrosion resistance of steel in different conditions. The results show that Rp practically does not change with the immersion time (until 8 hours, for both regions. The two regions have higher Rp in non-aerated aqueous solution, intermediate Rp in non-aerated with H2S and lower Rp in naturally aerated; this is due the effect of oxygen in cathodic reactions and shows that H2S can accelerate slightly the corrosion. The RCS has greater Rp than the MB for any aeration conditions. The presence of alloying elements in RCS justifies this behavior. The morphology of corrosion was examined under an optical microscope (MO and shows that uniform corrosion is predominant.

  7. High manganese non magnetic steel

    A high-manganese, non-magnetic steel is specified, having excellent weldability and machinability and suitable for use in the structural parts of electrical equipment or nuclear fusion equipment. (author)

  8. Overlay welding irradiated stainless steel

    An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,α reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods

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

    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

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

    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...

  11. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    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

  12. Chinese steel: limits to growth

    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.

  13. Streamlining Iron and Steel Production

    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

  14. MMFX Microcomposite Steel (MMFX2)

    ECT Team, Purdue

    2007-01-01

    One of the major problems facing the construction industry today is the effect of corrosion on steel, and the inherent structural weaknesses it causes in highways, bridges and buildings. MMFX 2 rebar was developed through the use of nanotechnology by Dr. Gareth Thomas, graduate school professor of materials science at Univ. of California, Berkeley. It is highly corrosion resistant and equal, or in many cases, far superior to existing conventional carbon steel in its properties of strength, en...

  15. Hydrogen embrittlement of ferritic steels

    Hydrogen embrittlement (HE) of ferritic and duplex stainless steels (SS) has been studied by charging annealed or quenched specimens with hydrogen through cathodic polarization. Cathodic charge has been found to reduce severely the ductility of these materials. Using microscopic observations (TEM and SEM and optical) attempts have been made to clarify the initial stage of microstructural changes which are induced by hydrogen charging in these steels. (author)

  16. Atmospheric corrosion of mild steel

    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...

  17. Fatigue Strength of Weathering Steel

    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...

  18. Fatigue properties of weathering steel

    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...

  19. Fatique behaviour of electrical steel

    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.

  20. Properties of hot rolled steels for enamelling

    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)

  1. Carbon Segregation of Bearing Steel Concasting Billet

    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.

  2. Review on Cold-Formed Steel Connections

    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

  3. Microbial corrosion of stainless steel.

    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

  4. Kinetics of borided gear steels

    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.

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

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

    2016-01-01

    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. PMID:26907242

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

    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.

  7. Irradiation embrittlement of ferritic stainless steels

    The characteristics of the irradiation embrittlement of some ferritic stainless steels were examined by tensile tests. Steels selected in this investigation were classified into three groups: chi phase, precipitation hardened Fe-13Cr steels; tempered martensitic Fe-12Cr steels; and low alloy steels. The latter steels were chosen in order to compare the irradiation embrittlement characteristics with those of stainless steels. The stainless steels were superior to the low alloy steels with regard to the irradiation embrittlement (the changes in both ductile-brittle transition temperature (DBTT) and unstable plastic flow transition temperature (UPFTT)), irrespective of whether these stainless steels had chi phase precipitated structures or tempered martensitic structures. The suppression of the DBTT increase owing to irradiation results from low yield stress increase Δσsub(y) and high |[dσsub(y)(u)/dT]|, where u denotes unirradiated, in the stainless steels. The suppression of the UPFTT results from the high work hardening rate or the high work exponent and the low Lueders strain in the stainless steels. These characteristics of irradiation embrittlement in the ferritic stainless steels are thought to be caused by the defect structure, which is modified by Cr atoms. (author)

  8. Anodized Steel Electrodes for Supercapacitors.

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-01

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime. PMID:26891093

  9. Classical nitriding of heat treatable steel

    Barrallier, Laurent

    2014-01-01

    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

  10. Steel erected at A-3 Test Stand

    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.