The Experts below are selected from a list of 966 Experts worldwide ranked by ideXlab platform
Kaneaki Tsuzaki - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Hydrogen entry into high strength steel under atmospheric corrosion
Corrosion Science, 2010Co-Authors: Eiji Akiyama, Mao Qiu Wang, Katsuhiro Matsukado, Kaneaki TsuzakiAbstract:Hydrogen entry into high strength steels by atmospheric corrosion has been investigated to evaluate their susceptibility to Hydrogen embrittlement. High strength steels were corroded by dry/wet cyclic corrosion after NaCl deposition. The maximum Diffusible Hydrogen concentration around the surface was successfully obtained by means of thermal desorption analysis after keeping the specimens at high humidity to reproduce enhanced Hydrogen entry influenced by the rust layer and to homogenize the Hydrogen distribution. Despite decrease in corrosion rate, Hydrogen content in specimens did not decrease. Decrease of pH in inner rust layer is responsible for the enhanced Hydrogen entry into steel.
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evaluation of susceptibility of high strength steels to delayed fracture by using cyclic corrosion test and slow strain rate test
Corrosion Science, 2010Co-Authors: Zuogui Zhang, Songjie Li, Kaneaki Tsuzaki, Eiji Akiyama, Boping ZhangAbstract:To evaluate susceptibilities of high strength steels to delayed fracture, slow strain rate tests (SSRT) of notched bar specimens of AISI 4135 with tensile strengths of 1300 and 1500 MPa and boron-bearing steel with 1300 MPa have been performed after cyclic corrosion test (CCT). During SSRT the humidity around the specimen was kept high to keep absorbed Diffusible Hydrogen. The fracture stresses of AISI 4135 steels decreased with increment of Diffusible Hydrogen content which increased with CCT cycles. Their delayed fracture susceptibilities could be successfully evaluated in consideration of both influence of Hydrogen content on mechanical property and Hydrogen entry.
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effect of Hydrogen on the fracture behavior of high strength steel during slow strain rate test
Corrosion Science, 2007Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The effect of Hydrogen on the fracture behavior of the quenched and tempered AISI 4135 steel at 1450 MPa has been investigated by means of slow strain rate tests on smooth and circumferentially-notched round-bar specimens. Hydrogen was introduced into specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS) analysis. Results showed that the steel had high Hydrogen embrittlement susceptibility. For both smooth and notched specimens, the fracture mode was changed from microvoid coalescence (MVC) to brittle intergranular (IG) fracture after the introduction of a small amount of Diffusible Hydrogen. Fracture initiated in the vicinity of the notch root for notched specimens, while it started from around the center in smooth specimens. The fracture stress decreased with increasing Diffusible Hydrogen content, and the decreasing trend was more prominent for specimens with a higher stress concentration factor. Taking into account the stress-driven Hydrogen diffusion and accumulation in the vicinity of the notch root, the local Diffusible Hydrogen concentration and local fracture stress in notched specimens have been calculated. According to numerical results, the relationship between the local fracture stress and local Diffusible Hydrogen concentration was independent of stress concentration factor, which could account for the effect of Hydrogen on the fracture stress of the steel.
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Hydrogen entry in crevice region evaluation by Hydrogen permeation technique
Isij International, 2006Co-Authors: T Sundararajan, Eiji Akiyama, Yasuyuki Katada, Kaneaki TsuzakiAbstract:Pure iron exposed to acetate buffer showed both metal dissolution and Hydrogen evolution inside the crevice region. Potential drop occurred inside the crevice led to both active dissolution and cathodic reactions. Hydrogen ingress into the specimen was monitored on the rear side using electrochemical Hydrogen permeation technique. The results showed that magnitude of Hydrogen entered inside the crevice could be detected by the permeation technique. Change in the applied potential significantly influenced the amount of permeated Hydrogen. The results are correlated potential drop occurred inside the crevice, which influenced the magnitude of Diffusible Hydrogen.
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effect of Hydrogen and stress concentration on the notch tensile strength of aisi 4135 steel
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The quantitative relationship between notch tensile strength and Diffusible Hydrogen content has been investigated for the AISI 4135 steel at 1320 MPa. The notch tensile strength was obtained by means of a slow strain rate test on circumferentially notched round bar specimens with stress concentration factors of 2.1, 3.3 and 4.9 after Hydrogen charging, and the Diffusible Hydrogen content was then measured by thermal desorption spectrometry analysis. The Diffusible Hydrogen has been found to decrease the notch tensile strength in a power law manner, and the decrease is more prominent at a higher stress concentration factor. The finite element analysis results of stress and Hydrogen distributions in the vicinity of the notch root have shown that the local fracture stress decreases with increasing local Hydrogen concentration as the Diffusible Hydrogen content or stress concentration factor increases, resulting in the decrease in the notch tensile strength.
Eiji Akiyama - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Hydrogen entry into high strength steel under atmospheric corrosion
Corrosion Science, 2010Co-Authors: Eiji Akiyama, Mao Qiu Wang, Katsuhiro Matsukado, Kaneaki TsuzakiAbstract:Hydrogen entry into high strength steels by atmospheric corrosion has been investigated to evaluate their susceptibility to Hydrogen embrittlement. High strength steels were corroded by dry/wet cyclic corrosion after NaCl deposition. The maximum Diffusible Hydrogen concentration around the surface was successfully obtained by means of thermal desorption analysis after keeping the specimens at high humidity to reproduce enhanced Hydrogen entry influenced by the rust layer and to homogenize the Hydrogen distribution. Despite decrease in corrosion rate, Hydrogen content in specimens did not decrease. Decrease of pH in inner rust layer is responsible for the enhanced Hydrogen entry into steel.
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evaluation of susceptibility of high strength steels to delayed fracture by using cyclic corrosion test and slow strain rate test
Corrosion Science, 2010Co-Authors: Zuogui Zhang, Songjie Li, Kaneaki Tsuzaki, Eiji Akiyama, Boping ZhangAbstract:To evaluate susceptibilities of high strength steels to delayed fracture, slow strain rate tests (SSRT) of notched bar specimens of AISI 4135 with tensile strengths of 1300 and 1500 MPa and boron-bearing steel with 1300 MPa have been performed after cyclic corrosion test (CCT). During SSRT the humidity around the specimen was kept high to keep absorbed Diffusible Hydrogen. The fracture stresses of AISI 4135 steels decreased with increment of Diffusible Hydrogen content which increased with CCT cycles. Their delayed fracture susceptibilities could be successfully evaluated in consideration of both influence of Hydrogen content on mechanical property and Hydrogen entry.
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effect of Hydrogen on the fracture behavior of high strength steel during slow strain rate test
Corrosion Science, 2007Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The effect of Hydrogen on the fracture behavior of the quenched and tempered AISI 4135 steel at 1450 MPa has been investigated by means of slow strain rate tests on smooth and circumferentially-notched round-bar specimens. Hydrogen was introduced into specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS) analysis. Results showed that the steel had high Hydrogen embrittlement susceptibility. For both smooth and notched specimens, the fracture mode was changed from microvoid coalescence (MVC) to brittle intergranular (IG) fracture after the introduction of a small amount of Diffusible Hydrogen. Fracture initiated in the vicinity of the notch root for notched specimens, while it started from around the center in smooth specimens. The fracture stress decreased with increasing Diffusible Hydrogen content, and the decreasing trend was more prominent for specimens with a higher stress concentration factor. Taking into account the stress-driven Hydrogen diffusion and accumulation in the vicinity of the notch root, the local Diffusible Hydrogen concentration and local fracture stress in notched specimens have been calculated. According to numerical results, the relationship between the local fracture stress and local Diffusible Hydrogen concentration was independent of stress concentration factor, which could account for the effect of Hydrogen on the fracture stress of the steel.
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Hydrogen entry in crevice region evaluation by Hydrogen permeation technique
Isij International, 2006Co-Authors: T Sundararajan, Eiji Akiyama, Yasuyuki Katada, Kaneaki TsuzakiAbstract:Pure iron exposed to acetate buffer showed both metal dissolution and Hydrogen evolution inside the crevice region. Potential drop occurred inside the crevice led to both active dissolution and cathodic reactions. Hydrogen ingress into the specimen was monitored on the rear side using electrochemical Hydrogen permeation technique. The results showed that magnitude of Hydrogen entered inside the crevice could be detected by the permeation technique. Change in the applied potential significantly influenced the amount of permeated Hydrogen. The results are correlated potential drop occurred inside the crevice, which influenced the magnitude of Diffusible Hydrogen.
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effect of Hydrogen and stress concentration on the notch tensile strength of aisi 4135 steel
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The quantitative relationship between notch tensile strength and Diffusible Hydrogen content has been investigated for the AISI 4135 steel at 1320 MPa. The notch tensile strength was obtained by means of a slow strain rate test on circumferentially notched round bar specimens with stress concentration factors of 2.1, 3.3 and 4.9 after Hydrogen charging, and the Diffusible Hydrogen content was then measured by thermal desorption spectrometry analysis. The Diffusible Hydrogen has been found to decrease the notch tensile strength in a power law manner, and the decrease is more prominent at a higher stress concentration factor. The finite element analysis results of stress and Hydrogen distributions in the vicinity of the notch root have shown that the local fracture stress decreases with increasing local Hydrogen concentration as the Diffusible Hydrogen content or stress concentration factor increases, resulting in the decrease in the notch tensile strength.
Mao Qiu Wang - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Hydrogen entry into high strength steel under atmospheric corrosion
Corrosion Science, 2010Co-Authors: Eiji Akiyama, Mao Qiu Wang, Katsuhiro Matsukado, Kaneaki TsuzakiAbstract:Hydrogen entry into high strength steels by atmospheric corrosion has been investigated to evaluate their susceptibility to Hydrogen embrittlement. High strength steels were corroded by dry/wet cyclic corrosion after NaCl deposition. The maximum Diffusible Hydrogen concentration around the surface was successfully obtained by means of thermal desorption analysis after keeping the specimens at high humidity to reproduce enhanced Hydrogen entry influenced by the rust layer and to homogenize the Hydrogen distribution. Despite decrease in corrosion rate, Hydrogen content in specimens did not decrease. Decrease of pH in inner rust layer is responsible for the enhanced Hydrogen entry into steel.
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effect of Hydrogen on the fracture behavior of high strength steel during slow strain rate test
Corrosion Science, 2007Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The effect of Hydrogen on the fracture behavior of the quenched and tempered AISI 4135 steel at 1450 MPa has been investigated by means of slow strain rate tests on smooth and circumferentially-notched round-bar specimens. Hydrogen was introduced into specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS) analysis. Results showed that the steel had high Hydrogen embrittlement susceptibility. For both smooth and notched specimens, the fracture mode was changed from microvoid coalescence (MVC) to brittle intergranular (IG) fracture after the introduction of a small amount of Diffusible Hydrogen. Fracture initiated in the vicinity of the notch root for notched specimens, while it started from around the center in smooth specimens. The fracture stress decreased with increasing Diffusible Hydrogen content, and the decreasing trend was more prominent for specimens with a higher stress concentration factor. Taking into account the stress-driven Hydrogen diffusion and accumulation in the vicinity of the notch root, the local Diffusible Hydrogen concentration and local fracture stress in notched specimens have been calculated. According to numerical results, the relationship between the local fracture stress and local Diffusible Hydrogen concentration was independent of stress concentration factor, which could account for the effect of Hydrogen on the fracture stress of the steel.
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effect of Hydrogen and stress concentration on the notch tensile strength of aisi 4135 steel
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The quantitative relationship between notch tensile strength and Diffusible Hydrogen content has been investigated for the AISI 4135 steel at 1320 MPa. The notch tensile strength was obtained by means of a slow strain rate test on circumferentially notched round bar specimens with stress concentration factors of 2.1, 3.3 and 4.9 after Hydrogen charging, and the Diffusible Hydrogen content was then measured by thermal desorption spectrometry analysis. The Diffusible Hydrogen has been found to decrease the notch tensile strength in a power law manner, and the decrease is more prominent at a higher stress concentration factor. The finite element analysis results of stress and Hydrogen distributions in the vicinity of the notch root have shown that the local fracture stress decreases with increasing local Hydrogen concentration as the Diffusible Hydrogen content or stress concentration factor increases, resulting in the decrease in the notch tensile strength.
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Hydrogen degradation of a boron bearing steel with 1050 and 1300mpa strength levels
Scripta Materialia, 2005Co-Authors: Mao Qiu Wang, Eiji Akiyama, Kaneaki TsuzakiAbstract:The maximum tensile stress of Hydrogen pre-charged specimens during slow strain rate test decreased in a power law manner with increasing Diffusible Hydrogen content in the presence of intergranular fracture. The lower Hydrogen degradation susceptibility at a lower strength level is due to delayed onset of intergranular fracture.
Thomas Hassel - One of the best experts on this subject based on the ideXlab platform.
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the applicability of the standard din en iso 3690 for the analysis of Diffusible Hydrogen content in underwater wet welding
Materials, 2020Co-Authors: Jan Klett, Thomas Wolf, H J Maier, Thomas HasselAbstract:The European standard ISO 3690 regulates the measurement of Diffusible Hydrogen in arc-welded metal. It was designed for different welding methods performed in dry atmosphere (20% humidity). Some details of the standard are not applicable for wet underwater welding. The objective of this study was to extend the applicability of DIN EN ISO 3690:2018-12 to underwater wet-shielded metal arc welding (SMAW). Four different aspects regulated within the standard were accounted for: (1) sample dimensions and number of samples taken simultaneously; (2) time limitations defined by the standard regarding the welding and the cleaning process; (3) time, temperature, and method defined for analysis of the Diffusible Hydrogen content; (4) normalization of the Hydrogen concentration measured. Underwater wet welding was performed using an automated, arc voltage-controlled welding machine. The results are discussed in light of standard DIN EN ISO 3690, and recommendations are provided for the analysis of Diffusible Hydrogen content upon underwater wet welding.
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Effect of the water depth on the Hydrogen content in SMAW wet welded joints
SN Applied Sciences, 2020Co-Authors: Jan Klett, Vitali Hecht-linowitzki, Oliver Grünzel, Emily Schmidt, Hans Jürgen Maier, Thomas HasselAbstract:Hydrogen-induced cold cracking is a huge challenge in underwater wet welding. In the present study, the influence of water depth on the Diffusible and residually stored Hydrogen content is investigated for the case of underwater wet shielded metal arc welding. The welding is carried out in a simulated water depth of 5, 20, 40, and 60 m with four stick electrodes specifically developed for underwater wet welding. The influence of the welding current, the arc voltage and the electrode’s composition on the Diffusible Hydrogen content are considered. To obtain reproducible welding conditions, a fully automated multi-axis welding system is used inside a pressure chamber. The water depth is simulated by setting the internal pressure up to 6 bar, equivalent to 60 m water depth. A large amount of samples are analysed and statistical method are used to evaluate the results. The results show a significant reduction of the Diffusible Hydrogen and an increase of residual Hydrogen in the joining zone with increasing water depth.
Grzegorz Rogalski - One of the best experts on this subject based on the ideXlab platform.
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possibilities of Diffusible Hydrogen control in welded joints
Welding Technology Review, 2017Co-Authors: Dariusz Fydrych, Aleksandra świerczynska, Grzegorz Rogalski, Jerzy łabanowskiAbstract:The paper discusses metallurgical and technological factors in uencing the presence of Diffusible Hydrogen in deposited metal obtained in air and in underwater environment, and methods of reducing its amount in welded joints are described. The results of studies aimed at determining the in uence of conditions and welding parameters on the Hydrogenation of deposited metal are presented. Relationships enabling prediction of the Hydrogen content in the joints made under water and in air with the most widely used welding processes have been developed and reported. in polish Mozliwości sterowania ilością wodoru dyfundującego w zlączach spawanych W pracy omowiono metalurgiczne i technologiczne czynniki wplywające na obecnośc wodoru dyfundującego w stopiwie uzyskanym w środowisku powietrznym i pod wodą oraz podano metody obnizania jego ilości w zlączach spawanych. Przedstawiono wyniki badan ukierunkowanych na określenie wplywu warunkow i parametrow spawania na nawodorowanie stopiwa. Opracowano i podano zalezności umozliwiające prognozowanie zawartości wodoru w zlączach wykonanych pod wodą i na powietrzu najcześciej stosowanymi procesami spawania.
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Diffusible Hydrogen management in underwater wet self shielded flux cored arc welding
International Journal of Hydrogen Energy, 2017Co-Authors: Aleksandra świerczynska, Dariusz Fydrych, Grzegorz RogalskiAbstract:This article reports the effect of underwater wet welding parameters and conditions on the Diffusible Hydrogen content in deposited metal for welding with a self-shielded flux cored wire. The Diffusible Hydrogen content in deposited metal was determined using the glycerin method according to the Plackett-Burman design determining the significance of the effect of the stick out length, welding current, arc voltage, travel speed and water salinity. The results of the measurements of the Diffusible Hydrogen content in deposited metal ranged from 25.85 to 44.12 ml/100 g. The effect of all the tested factors is statistically significant. An equation was also developed, the analysis of which showed, that the Hydrogen content cannot be reduced by technological methods below 21 ml/100 g.
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pomiary ilości wodoru dyfundującego w stopiwie elektrod celulozowych i zasadowych determination of Diffusible Hydrogen content in deposited metal of cellulosic and basic electrodes
Przegląd Spawalnictwa - Welding Technology Review, 2014Co-Authors: Dariusz Fydrych, Aleksandra świerczynska, Piotr Malinowski, Grzegorz RogalskiAbstract:W artykule scharakteryzowano technologie wytwarzania zlączy poprzecznych rurociągow energetycznych w aspekcie kontroli ilości wodoru dyfundującego. Oznaczono zawartośc wodoru dyfundującego w stopiwie dla zlączy wielościegowych wykonanych elektrodami w otulinie celulozowej i zasadowej. Ustalono, ze po wykonaniu 4 ściegow ilośc wodoru dyfundującego spada z ok. 40 ml/100 g do 12 ml/100 g i podjeto probe wyjaśnienia mechanizmow odpowiedzialnych za to zjawisko. Abstract The article describes manufacturing technology of circumferential joints of transportation pipelines in terms of control the Diffusible Hydrogen content. Diffusible Hydrogen content in deposited metal for multilayer joints made of coated cellulosic and basic electrodes was determined. It was found that after four beads the Diffusible Hydrogen content decreases from about 40 ml/100 g to 12 ml/100 g. The explanation of the mechanisms responsible for this phenomenon was proposed.
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Diffusible Hydrogen content in deposited metal of multilayer welded joints
Metallurgy and Foundry Engineering, 2014Co-Authors: Dariusz Fydrych, Aleksandra świerczynska, Grzegorz RogalskiAbstract:The article describes manufacturing technology of multilayer joints in terms of control the Diffusible Hydrogen content. Diffusible Hydrogen content in deposited metal for multilayer welded joints made of covered rutile electrodes or covered cellulosic and basic electrodes was determined. It was found that after four beads, the Diffusible Hydrogen content decreases in the case of the first technology from 36 ml/100 g to 18 ml/100 g while in the second of about 40 ml/100 g to a level of 12 ml/100 g. The explanation of the mechanisms responsible for this phenomenon and directions for further study were proposed.
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effect of underwater local cavity welding method conditions on Diffusible Hydrogen content in deposited metal
Welding International, 2013Co-Authors: Dariusz Fydrych, Grzegorz RogalskiAbstract:One of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and Diffusible Hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on Diffusible Hydrogen amount in a deposited metal. A Plackett–Burman design was applied to screen seven parameters: thickness of elastic cover, stick-out of electrode wire, welding current, voltage, travel speed of welding, salinity of water, and flow rate of shielding gas.