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Mimoun Elboujdaini - One of the best experts on this subject based on the ideXlab platform.
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Sulfide Stress Cracking resistance of api x100 high strength low alloy steel
Materials & Design, 2009Co-Authors: Mohammed Almansour, Akram Alfantazi, Mimoun ElboujdainiAbstract:Abstract Sulfide Stress Cracking (SSC) of API-X100 high strength low alloy steel was evaluated in NACE solution “A” at room temperature. The corrosion rate, utilizing electrochemical polarization techniques, in the solution was 97 mpy. Proof ring testing, per NACE TM-0177, generated an SSC threshold Stress value of 46% of yield strength. SSC susceptibility was caused by the high corrosion rate which formed corrosion pits that acted as crack initiation sites on the metal surface and provided more hydrogen to migrate into the steel. In addition, the X100 inhomogeneous microstructure provided a high density of hydrogen traps which promoted hydrogen embrittlement.
T. Cassagne - One of the best experts on this subject based on the ideXlab platform.
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Contribution of CO2 on hydrogen evolution and hydrogen permeation in low alloy steels exposed to H2S environment
Electrochemistry Communications, 2013Co-Authors: C. Plennevaux, M. Fr??gon??se, Francois Ropital, Fabrizio Grosjean, Bernard Normand, Jean Kittel, T. CassagneAbstract:Hydrogen charging in low alloy steels is a major problem in oil and gas environments containing hydrogen Sulfide (H2S). The risk of Sulfide Stress Cracking (SSC) is usually determined from the values of water pH and H2S partial pressure (PH2S). The goal of the present study is to check if hydrogen charging is influenced by other parameters than the sole pH and PH2S, and especially by carbon dioxide (CO2). Experiments engaged the measurement of hydrogen permeation through thin mild steel membranes under potentiometric control. Charging solutions with different H2S concentrations with or without CO2 were used, in order to examine their individual contributions to the charging flux. ?? 2012 Elsevier B.V. All rights reserved.
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contribution of acoustic emission to the understanding of Sulfide Stress Cracking of low alloy steels
Corrosion Science, 2011Co-Authors: V. Smanio, T. Cassagne, Francois Ropital, Jean Kittel, Marion Fregonese, Bernard NormandAbstract:Abstract The acoustic emission technique was applied to standard tests devoted to evaluate Sulfide Stress Cracking susceptibility of steels for oil and gas industry. The mapping of the density of AE signals vs. their location on the specimen gauge length as a function of time allowed early detection of Cracking, and gave meaningful information on incubation times and propagation rates. Sulfide Stress Cracking initiation was correlated with the presence of critical surface defects. A mechanism involving plastic strain and/or metal dissolution was proposed to account for crack propagation.
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Acoustic Emission Monitoring of Wet H2S Cracking of Linepipe Steels: Application to Hydrogen-Induced Cracking and Stress-Oriented Hydrogen-Induced Cracking
CORROSION, 2011Co-Authors: V. Smanio, T. Cassagne, Bernard Normand, Jean Kittel, Marion Fregonese, Francois RopitalAbstract:cited By 9International audienceAcoustic emission (AE) was used for monitoring steel Cracking during exposure to wet hydrogen Sulfide (H2S) environments. A method for filtering AE data related to hydrogen-induced Cracking (HIC) was presented and applied for several case studies. In a series of tests on unStressed sweet service steels, evolution of AE indicated three successive HIC phases. An initial incubation period corresponded to hydrogen entry in the steel, during which no Cracking occurred. Then two Cracking phases were detected. The first was associated with decohesion of weak steel interphases. The second was identified as crack propagation under high internal hydrogen pressure. Crack propagation decreased and eventually ceased over time. Analysis of AE data was then used to evaluate the extent of HIC after sour exposure. Correlation was found when appropriate data filtering was applied. AE analysis was also applied to sour service steels under an applied load. The first steel exhibited HIC AE signals. Its fracture surface was typical of a Stress-oriented hydrogen-induced Cracking (SOHIC) mode of failure, in good agreement with AE results. For the second steel, which also failed during the test, no AE related to HIC was detected. Fracture surface was typical of Sulfide Stress Cracking (SSC), also in good agreement with AE findings. © 2011, NACE International
Bernard Normand - One of the best experts on this subject based on the ideXlab platform.
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Contribution of CO2 on hydrogen evolution and hydrogen permeation in low alloy steels exposed to H2S environment
Electrochemistry Communications, 2013Co-Authors: C. Plennevaux, M. Fr??gon??se, Francois Ropital, Fabrizio Grosjean, Bernard Normand, Jean Kittel, T. CassagneAbstract:Hydrogen charging in low alloy steels is a major problem in oil and gas environments containing hydrogen Sulfide (H2S). The risk of Sulfide Stress Cracking (SSC) is usually determined from the values of water pH and H2S partial pressure (PH2S). The goal of the present study is to check if hydrogen charging is influenced by other parameters than the sole pH and PH2S, and especially by carbon dioxide (CO2). Experiments engaged the measurement of hydrogen permeation through thin mild steel membranes under potentiometric control. Charging solutions with different H2S concentrations with or without CO2 were used, in order to examine their individual contributions to the charging flux. ?? 2012 Elsevier B.V. All rights reserved.
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contribution of acoustic emission to the understanding of Sulfide Stress Cracking of low alloy steels
Corrosion Science, 2011Co-Authors: V. Smanio, T. Cassagne, Francois Ropital, Jean Kittel, Marion Fregonese, Bernard NormandAbstract:Abstract The acoustic emission technique was applied to standard tests devoted to evaluate Sulfide Stress Cracking susceptibility of steels for oil and gas industry. The mapping of the density of AE signals vs. their location on the specimen gauge length as a function of time allowed early detection of Cracking, and gave meaningful information on incubation times and propagation rates. Sulfide Stress Cracking initiation was correlated with the presence of critical surface defects. A mechanism involving plastic strain and/or metal dissolution was proposed to account for crack propagation.
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Acoustic Emission Monitoring of Wet H2S Cracking of Linepipe Steels: Application to Hydrogen-Induced Cracking and Stress-Oriented Hydrogen-Induced Cracking
CORROSION, 2011Co-Authors: V. Smanio, T. Cassagne, Bernard Normand, Jean Kittel, Marion Fregonese, Francois RopitalAbstract:cited By 9International audienceAcoustic emission (AE) was used for monitoring steel Cracking during exposure to wet hydrogen Sulfide (H2S) environments. A method for filtering AE data related to hydrogen-induced Cracking (HIC) was presented and applied for several case studies. In a series of tests on unStressed sweet service steels, evolution of AE indicated three successive HIC phases. An initial incubation period corresponded to hydrogen entry in the steel, during which no Cracking occurred. Then two Cracking phases were detected. The first was associated with decohesion of weak steel interphases. The second was identified as crack propagation under high internal hydrogen pressure. Crack propagation decreased and eventually ceased over time. Analysis of AE data was then used to evaluate the extent of HIC after sour exposure. Correlation was found when appropriate data filtering was applied. AE analysis was also applied to sour service steels under an applied load. The first steel exhibited HIC AE signals. Its fracture surface was typical of a Stress-oriented hydrogen-induced Cracking (SOHIC) mode of failure, in good agreement with AE results. For the second steel, which also failed during the test, no AE related to HIC was detected. Fracture surface was typical of Sulfide Stress Cracking (SSC), also in good agreement with AE findings. © 2011, NACE International
Ke Yang - One of the best experts on this subject based on the ideXlab platform.
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strengthening and improvement of Sulfide Stress Cracking resistance in acicular ferrite pipeline steels by nano sized carbonitrides
Scripta Materialia, 2005Co-Authors: Ming-chun Zhao, Ke YangAbstract:Methods used to strengthen pipeline steels generally involve a reduction in their Sulfide Stress Cracking (SSC) resistance. A non-quench ageing process is proposed to provide higher strength combined with more excellent SSC resistance for acicular ferrite (AF) pipeline steels, while microstructural characteristics are retained. (C) 2005 Acta Materiala Inc. Published by Elsevier Ltd. All rights reserved.
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effects of nano sized microalloyed carbonitrides and high density pinned dislocations on Sulfide Stress Cracking resistance of pipeline steels
Journal of Materials Research, 2005Co-Authors: Ming-chun Zhao, Ke YangAbstract:Sulfide Stress Cracking (SSC) resistance was investigated by comparing acicular ferrite (AF) and ferrite-pearlite (FP) in a microalloyed steel and in a non-microalloyedsteel. In microalloyed steel, AF exhibited better SSC resistance than FP, while in non-microalloyed steel, AF presented far worse SSC resistance than FP. In microalloyed steel, nano-sized carbonitrides and high-density pinned dislocations in AF were analyzed to behave as innocuous hydrogen traps, offering numerous sites for hydrogen redistribution and modifying critical Cracking conditions. Dislocations in AF of microalloyed steel in the final analysis are attributed to pinning by the nano-sized carbonitrides.
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Role of microstructure on Sulfide Stress Cracking of oil and gas pipeline steels
Metallurgical and Materials Transactions A, 2003Co-Authors: Ming-chun Zhao, Bei Tang, Yi-yin Shan, Ke YangAbstract:Sulfide Stress Cracking (SSC) behavior of three microstructures, i.e., ferritic-pearlitic microstructure, ultrafine ferrite microstructure, and acicular ferrite dominated microstructure, was investigated using the bent-beam test in aqueous hydrogen Sulfide (H2S) environments. The critical Stress (Sc) values of these three microstructures were determined experimentally to be 1008, 1190, and more than 1260 MPa, respectively. As a result, the acicular ferrite-dominated microstructure possessed the best SSC resistance, the ultrafine ferrite microstructure was in a second position, and the ferritic-pearlitic microstructure was relatively the worst. It was analyzed that hydrogen embrittlement (HE) was the main failure mechanism in SSC Cracking for high-strength pipeline steels, and preferential hydrogen accumulation within the plastic zone of the main crack tip accounted for the exhibited embrittlement. It was remarkable that the strength values of pipeline steels were not the only factor to determine their SSC susceptibilities. Microstructure played an important role in the SSC initiation and propagation of pipeline steels. In particular, both the fine dispersed precipitations of carbonitrides and the high-density tangled dislocations in acicular ferrite, which behaved as the hydrogen traps, should be attributed to the optimal SSC resistance of pipeline steels.
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Investigation on the H2S-resistant behaviors of acicular ferrite and ultrafine ferrite
Materials Letters, 2002Co-Authors: Ming-chun Zhao, Furen Xiao, Yi-ying Shan, Ke YangAbstract:Hydrogen-induced Cracking (HIC) and Sulfide Stress Cracking (SSC) of both acicular ferrite and ultrafine ferrite in H2S environments were evaluated. The results show that the two microstructures have the optimum HIC resistance as well as the good mechanical properties. Moreover, acicular ferrite has the better SSC resistance than ultrafine ferrite. (C) 2002 Elsevier Science B.V. All rights reserved.
Mohammed Almansour - One of the best experts on this subject based on the ideXlab platform.
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Sulfide Stress Cracking resistance of api x100 high strength low alloy steel
Materials & Design, 2009Co-Authors: Mohammed Almansour, Akram Alfantazi, Mimoun ElboujdainiAbstract:Abstract Sulfide Stress Cracking (SSC) of API-X100 high strength low alloy steel was evaluated in NACE solution “A” at room temperature. The corrosion rate, utilizing electrochemical polarization techniques, in the solution was 97 mpy. Proof ring testing, per NACE TM-0177, generated an SSC threshold Stress value of 46% of yield strength. SSC susceptibility was caused by the high corrosion rate which formed corrosion pits that acted as crack initiation sites on the metal surface and provided more hydrogen to migrate into the steel. In addition, the X100 inhomogeneous microstructure provided a high density of hydrogen traps which promoted hydrogen embrittlement.
