This paper compares engineering J estimates for Spent Fuel Canisters (SFCs) under combined mechanical and welding residual stress (WRS) with finite element (FE) results. Engineering J estimates are based on reference stress method provided in the R6 procedure considering interaction between primary and secondary stresses using the V-factor. It is found that residual stress should be considered in fracture assessment and the R6 estimates are reasonably conservative compared to FE analysis results.
{"title":"Engineering J Estimates for Spent Fuel Canisters Under Combined Mechanical and Welding Residual Stresses","authors":"Hyunjung Lee, Yun‐Jae Kim, P. Lam, R. Sindelar","doi":"10.1115/pvp2019-93936","DOIUrl":"https://doi.org/10.1115/pvp2019-93936","url":null,"abstract":"\u0000 This paper compares engineering J estimates for Spent Fuel Canisters (SFCs) under combined mechanical and welding residual stress (WRS) with finite element (FE) results. Engineering J estimates are based on reference stress method provided in the R6 procedure considering interaction between primary and secondary stresses using the V-factor. It is found that residual stress should be considered in fracture assessment and the R6 estimates are reasonably conservative compared to FE analysis results.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79196047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the piping fabrication industry Gas Tungsten Arc Welding (GTAW) is used extensively for welding of stainless and high alloy steel pipes, mainly for root pass of single side joints. GTAW process uses an inert gas for both shielding and backing of the weld. Backing gas also known as purge gas, is provided mainly to prevent oxidation of root pass weld from inside the pipe. Typically, Argon or Argon mixture (i.e. Argon with Helium, etc.) are used as backing gas. Argon gas, is colorless, odorless and heavier than air. Many safety incidents have occurred in the Oil and Gas industry (mainly during construction phase) due to asphyxiation. This has typically occurred when a person (usually a welder) goes inside the piping (a confined space) to inspect the root pass weld to ensure it will pass radiography test. Construction industry has failed to fully tackle this issue in a meaningful way and as a result, some significant number of fatalities occur each year. On several occasions, such incidents have resulted in multiple fatalities when coworkers enter the confined space to rescue and become a victim by themselves. There are a multitude of reasons why people put themselves at risk in this way. Reasons given for a reluctance to use alternative techniques that eliminates backing gas are many and varied. Alternate welding techniques without backing gas were developed many years ago. However, they are still not being used extensively for many reasons and apprehensions. Using these alternate welding techniques with right controls in place, can eliminate the hazard associated with backing gas and improve safety and maintain quality. This paper discusses and evaluates the alternate welding techniques (which do not require backing gas), limitations, welding procedure qualification and inspection requirements.
{"title":"Evaluation of Welding Techniques for Stainless Steels Piping Without Use of Backing Gas","authors":"Siva Kumar Chiluvuri, Kevin J. Bliss, J. Penso","doi":"10.1115/pvp2019-93359","DOIUrl":"https://doi.org/10.1115/pvp2019-93359","url":null,"abstract":"\u0000 In the piping fabrication industry Gas Tungsten Arc Welding (GTAW) is used extensively for welding of stainless and high alloy steel pipes, mainly for root pass of single side joints. GTAW process uses an inert gas for both shielding and backing of the weld. Backing gas also known as purge gas, is provided mainly to prevent oxidation of root pass weld from inside the pipe. Typically, Argon or Argon mixture (i.e. Argon with Helium, etc.) are used as backing gas. Argon gas, is colorless, odorless and heavier than air. Many safety incidents have occurred in the Oil and Gas industry (mainly during construction phase) due to asphyxiation. This has typically occurred when a person (usually a welder) goes inside the piping (a confined space) to inspect the root pass weld to ensure it will pass radiography test. Construction industry has failed to fully tackle this issue in a meaningful way and as a result, some significant number of fatalities occur each year. On several occasions, such incidents have resulted in multiple fatalities when coworkers enter the confined space to rescue and become a victim by themselves.\u0000 There are a multitude of reasons why people put themselves at risk in this way. Reasons given for a reluctance to use alternative techniques that eliminates backing gas are many and varied. Alternate welding techniques without backing gas were developed many years ago. However, they are still not being used extensively for many reasons and apprehensions. Using these alternate welding techniques with right controls in place, can eliminate the hazard associated with backing gas and improve safety and maintain quality. This paper discusses and evaluates the alternate welding techniques (which do not require backing gas), limitations, welding procedure qualification and inspection requirements.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83002572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Takakuwa, Yuhei Ogawa, S. Okazaki, H. Matsunaga, S. Matsuoka
In order to elucidate the temperature dependence of hydrogen-assisted fatigue crack growth (HAFCG), the fatigue crack growth (FCG) test was performed on low-carbon steel JIS-SM490B according to ASTM E647 using compact tension (CT) specimen under 0.7 MPa (≈ 0.1 ksi) hydrogen-gas at room temperature (RT: 298 K (≈ 77 °F)) and 423 K (≈ 302 °F) at stress intensity factor range of ΔK = 30 MPa m1/2 (≈ 27 ksi in1/2). Electron backscatter diffraction (EBSD) observation was performed on the mid-thick section of CT specimen in order to investigate change in plasticity around the crack wake in gaseous hydrogen environment and how it changes due to temperature elevation. The obtained results showed the higher temperature, the lower intense of HAFCG as reported in our previous article. Plasticity around the crack wake became less in gaseous hydrogen environment, especially tested at 298 K. The propensity of the results obtained at higher temperature (423 K) can be separated into two cases: (i) intense plasticity occurs like tested in air, (ii) crack propagates straighter accompanying less plasticity like tested in gaseous hydrogen environment at 298 K. This implies macroscopic FCG rate is determined by combination of microscopic FCG rate in the case (i) and case (ii).
{"title":"Temperature Dependence of Fatigue Crack Growth in Low-Carbon Steel Under Gaseous Hydrogen","authors":"O. Takakuwa, Yuhei Ogawa, S. Okazaki, H. Matsunaga, S. Matsuoka","doi":"10.1115/pvp2019-93451","DOIUrl":"https://doi.org/10.1115/pvp2019-93451","url":null,"abstract":"\u0000 In order to elucidate the temperature dependence of hydrogen-assisted fatigue crack growth (HAFCG), the fatigue crack growth (FCG) test was performed on low-carbon steel JIS-SM490B according to ASTM E647 using compact tension (CT) specimen under 0.7 MPa (≈ 0.1 ksi) hydrogen-gas at room temperature (RT: 298 K (≈ 77 °F)) and 423 K (≈ 302 °F) at stress intensity factor range of ΔK = 30 MPa m1/2 (≈ 27 ksi in1/2). Electron backscatter diffraction (EBSD) observation was performed on the mid-thick section of CT specimen in order to investigate change in plasticity around the crack wake in gaseous hydrogen environment and how it changes due to temperature elevation. The obtained results showed the higher temperature, the lower intense of HAFCG as reported in our previous article. Plasticity around the crack wake became less in gaseous hydrogen environment, especially tested at 298 K. The propensity of the results obtained at higher temperature (423 K) can be separated into two cases: (i) intense plasticity occurs like tested in air, (ii) crack propagates straighter accompanying less plasticity like tested in gaseous hydrogen environment at 298 K. This implies macroscopic FCG rate is determined by combination of microscopic FCG rate in the case (i) and case (ii).","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79652874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Metallographic tests, micro-hardness tests and tensile tests were conducted for a 1.25Cr-0.5Mo main steam pipe weldment served for more than 26 years. The results were compared with those for virgin material. Microstructural evolution of 1.25Cr-0.5Mo base metal was investigated. Degradation in micro-hardness and tensile properties were also studied. In addition, the tensile properties of subzones in the ex-service weldment were characterized by using miniature specimens. The results show that obvious microstructural changes including carbide coarsening, increasing inter lamella spacing and grain boundary precipitates take place after long-term service. Degradation in micro-hardness is not obvious. However, the effects of long term service on tensile deformation behavior, ultimate tensile strength and yield stress are remarkable. Based on the yield stress of micro-specimens, the order of different subzones is: WM > HAZ > BM, which is consistent with the order of different subzones based on micro-hardness. However, the ultimate tensile strength and fracture strain of HAZ are lower than BM. Brittle failures can happen more easily for HAZ due to its high yield ratio.
{"title":"Microstructure and Tensile Properties of a 1.25Cr-0.5Mo Main Steam Pipe After Long-Term Service","authors":"Bingxiu Yang, Wenchun Jiang, Wenjuan Sun, Yan-ling Zhao, Weiya Zhang","doi":"10.1115/PVP2018-84185","DOIUrl":"https://doi.org/10.1115/PVP2018-84185","url":null,"abstract":"Metallographic tests, micro-hardness tests and tensile tests were conducted for a 1.25Cr-0.5Mo main steam pipe weldment served for more than 26 years. The results were compared with those for virgin material. Microstructural evolution of 1.25Cr-0.5Mo base metal was investigated. Degradation in micro-hardness and tensile properties were also studied. In addition, the tensile properties of subzones in the ex-service weldment were characterized by using miniature specimens. The results show that obvious microstructural changes including carbide coarsening, increasing inter lamella spacing and grain boundary precipitates take place after long-term service. Degradation in micro-hardness is not obvious. However, the effects of long term service on tensile deformation behavior, ultimate tensile strength and yield stress are remarkable. Based on the yield stress of micro-specimens, the order of different subzones is: WM > HAZ > BM, which is consistent with the order of different subzones based on micro-hardness. However, the ultimate tensile strength and fracture strain of HAZ are lower than BM. Brittle failures can happen more easily for HAZ due to its high yield ratio.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84362762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woo-Gon Kim, Jae-Young Park, H. Lee, Eungseon Kim, Seon-Jin Kim
This study presents assessment of creep crack growth rates (CCGRs) for the base metal (BM), weld metal (WM), and heat affected zone (HAZ) of Gr. 91 weld joint, which was prepared by a shield metal arc weld (SMAW) method. A series of tensile, creep, creep crack growth (CCG) tests were performed for the BM, WM, and HAZ at the identical temperature of 550°C. The CCGR laws for the BM, WM and HAZ were constructed and compared in terms of a C*-fracture parameter. In addition, the CCGR law tested for BM was compared to that of RCC-MRx code. For a given value of C*, the WM and HAZ were almost similar in the CCGR, but they were significantly faster than the BM. This reason was closely attributed to the higher creep rate in the WM and HAZ than the BM. Currently elevated temperature design (ETD) code in French, RCC-MRx was found to be non-conservative in the CCGR when compared with the present investigation.
{"title":"Assessment of Creep Crack Growth Rates for Grade 91 Weld Joint at 550°C","authors":"Woo-Gon Kim, Jae-Young Park, H. Lee, Eungseon Kim, Seon-Jin Kim","doi":"10.1115/PVP2018-84604","DOIUrl":"https://doi.org/10.1115/PVP2018-84604","url":null,"abstract":"This study presents assessment of creep crack growth rates (CCGRs) for the base metal (BM), weld metal (WM), and heat affected zone (HAZ) of Gr. 91 weld joint, which was prepared by a shield metal arc weld (SMAW) method. A series of tensile, creep, creep crack growth (CCG) tests were performed for the BM, WM, and HAZ at the identical temperature of 550°C. The CCGR laws for the BM, WM and HAZ were constructed and compared in terms of a C*-fracture parameter. In addition, the CCGR law tested for BM was compared to that of RCC-MRx code. For a given value of C*, the WM and HAZ were almost similar in the CCGR, but they were significantly faster than the BM. This reason was closely attributed to the higher creep rate in the WM and HAZ than the BM. Currently elevated temperature design (ETD) code in French, RCC-MRx was found to be non-conservative in the CCGR when compared with the present investigation.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73122101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Nanstad, W. Server, M. Sokolov, G. Odette, N. Almirall
The use of correlations is common in the research and development arena of the nuclear industry with the realization that some applications with direct implications to safety demand a more rigorous approach. Most correlations involve the relationship between two experimental properties, such as that between hardness and tensile strength. There are others that are much more complicated and are often designated models because they incorporate physically-based knowledge; examples of this are predictive correlations for irradiation-induced embrittlement of reactor pressure vessels (RPV). The objective of this paper is to collect and discuss many of the commonly used correlations for applications to nuclear RPVs. This paper identifies and discusses various correlations that relate easily measured properties to properties that are more difficult, more time consuming, or more expensive to measure. In the case of irradiated RPV materials, irradiation-induced changes in easily measured properties are related to the changes in those more difficult to measure. It is noted that recognition and understanding of the uncertainties associated with all correlations is highly important.
{"title":"Some Useful Mechanical Property Correlations for Nuclear Reactor Pressure Vessel Steels","authors":"R. Nanstad, W. Server, M. Sokolov, G. Odette, N. Almirall","doi":"10.1115/PVP2018-84786","DOIUrl":"https://doi.org/10.1115/PVP2018-84786","url":null,"abstract":"The use of correlations is common in the research and development arena of the nuclear industry with the realization that some applications with direct implications to safety demand a more rigorous approach. Most correlations involve the relationship between two experimental properties, such as that between hardness and tensile strength. There are others that are much more complicated and are often designated models because they incorporate physically-based knowledge; examples of this are predictive correlations for irradiation-induced embrittlement of reactor pressure vessels (RPV). The objective of this paper is to collect and discuss many of the commonly used correlations for applications to nuclear RPVs. This paper identifies and discusses various correlations that relate easily measured properties to properties that are more difficult, more time consuming, or more expensive to measure. In the case of irradiated RPV materials, irradiation-induced changes in easily measured properties are related to the changes in those more difficult to measure. It is noted that recognition and understanding of the uncertainties associated with all correlations is highly important.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76741396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Takakuwa, S. Matsuoka, S. Okazaki, M. Yoshikawa, J. Yamabe, H. Matsunaga
In order to elucidate the temperature dependence of hydrogen-enhanced fatigue crack growth (FCG), the FCG test was performed on low-alloy Cr-Mo steel JIS-SCM435 according to ASTM E647 using compact tension (CT) specimen under 0.1–95 MPa hydrogen-gas at temperature ranging from room temperature (298 K) to 423 K. The obtained results were interpreted according to trap site occupancy under thermal equilibrium state. The FCG was significantly accelerated at RT under hydrogen-gas, that its maximum acceleration rate of the FCG was 15 at the pressure of 95 MPa at the temperature of 298 K. The hydrogen-enhanced FCG was mitigated due to temperature elevation for all pressure conditions. The trap site with binding energy of 44 kJ/mol dominated the temperature dependence of hydrogen-enhanced FCG, corresponding approximately to binding energy of dislocation core. The trap site (dislocation) occupancy is decreased with the temperature elevation, resulting in the mitigation of the FCG acceleration. On the basis of the obtained results, when the occupancy becomes higher at lower temperature, e.g. 298 K, hydrogen-enhanced FCG becomes more pronounced. The lower occupancy at higher temperature does the opposite.
{"title":"Temperature Dependence of Fatigue Crack Growth in Low-Alloy Steel Under Gaseous Hydrogen","authors":"O. Takakuwa, S. Matsuoka, S. Okazaki, M. Yoshikawa, J. Yamabe, H. Matsunaga","doi":"10.1115/PVP2018-84438","DOIUrl":"https://doi.org/10.1115/PVP2018-84438","url":null,"abstract":"In order to elucidate the temperature dependence of hydrogen-enhanced fatigue crack growth (FCG), the FCG test was performed on low-alloy Cr-Mo steel JIS-SCM435 according to ASTM E647 using compact tension (CT) specimen under 0.1–95 MPa hydrogen-gas at temperature ranging from room temperature (298 K) to 423 K. The obtained results were interpreted according to trap site occupancy under thermal equilibrium state. The FCG was significantly accelerated at RT under hydrogen-gas, that its maximum acceleration rate of the FCG was 15 at the pressure of 95 MPa at the temperature of 298 K. The hydrogen-enhanced FCG was mitigated due to temperature elevation for all pressure conditions. The trap site with binding energy of 44 kJ/mol dominated the temperature dependence of hydrogen-enhanced FCG, corresponding approximately to binding energy of dislocation core. The trap site (dislocation) occupancy is decreased with the temperature elevation, resulting in the mitigation of the FCG acceleration. On the basis of the obtained results, when the occupancy becomes higher at lower temperature, e.g. 298 K, hydrogen-enhanced FCG becomes more pronounced. The lower occupancy at higher temperature does the opposite.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78960883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Okazaki, H. Matsunaga, M. Nakamura, S. Hamada, S. Matsuoka
To investigate the influence of hydrogen on the tensile and fatigue life properties of welded joints of 304/308 austenitic stainless steels, slow strain rate tensile (SSRT) tests and fatigue life tests were conducted in laboratory air using hydrogen exposed specimens. The specimens were fabricated from welded plates, and to elucidate the role of weld structure on hydrogen-induced degradation, the welded joint was solution-treated. In the SSRT tests of the as-welded (AW) joint, a non-exposed specimen failed at the base metal (BM), whereas a hydrogen-exposed specimen failed near the weld toe. In the case of the solution-treated-welded (STW) joint, the non-exposed specimen failed at the part of solution treated weld metal, whereas an H-exposed specimen failed near the weld toe. As a result, internal hydrogen significantly degraded the elongation of the AW joint. In the fatigue test, all the specimens failed near the weld toe. Internal hydrogen degraded the fatigue life considerably. However, the pre-charging led to little, if any, reduction in the fatigue limit. Similarly to the AW joint, hydrogen gas exposure notably degraded the fatigue life of the STW joint and led to little reduction in the fatigue limit. To investigate the relationship between the hydrogen-induced degradation and strain-induced martensitic transformation during fatigue testing, the volume fraction of ferrite in the broken specimens was measured by a ferrite scope. The volume fraction of martensitic transformation increased with an increase in the stress amplitude. These experimental results implied that the hydrogen-induced fatigue life degradation in the welded joint was closely related to the martensitic transformation during the fatigue process. The mechanisms of both the degradation in fatigue life and nondegradation in fatigue limit will be discussed further.
{"title":"Influence of Hydrogen on Tensile and Fatigue Life Properties of 304/308 Austenitic Stainless Steel Butt Welded Joints","authors":"S. Okazaki, H. Matsunaga, M. Nakamura, S. Hamada, S. Matsuoka","doi":"10.1115/PVP2018-84781","DOIUrl":"https://doi.org/10.1115/PVP2018-84781","url":null,"abstract":"To investigate the influence of hydrogen on the tensile and fatigue life properties of welded joints of 304/308 austenitic stainless steels, slow strain rate tensile (SSRT) tests and fatigue life tests were conducted in laboratory air using hydrogen exposed specimens. The specimens were fabricated from welded plates, and to elucidate the role of weld structure on hydrogen-induced degradation, the welded joint was solution-treated. In the SSRT tests of the as-welded (AW) joint, a non-exposed specimen failed at the base metal (BM), whereas a hydrogen-exposed specimen failed near the weld toe. In the case of the solution-treated-welded (STW) joint, the non-exposed specimen failed at the part of solution treated weld metal, whereas an H-exposed specimen failed near the weld toe. As a result, internal hydrogen significantly degraded the elongation of the AW joint.\u0000 In the fatigue test, all the specimens failed near the weld toe. Internal hydrogen degraded the fatigue life considerably. However, the pre-charging led to little, if any, reduction in the fatigue limit. Similarly to the AW joint, hydrogen gas exposure notably degraded the fatigue life of the STW joint and led to little reduction in the fatigue limit. To investigate the relationship between the hydrogen-induced degradation and strain-induced martensitic transformation during fatigue testing, the volume fraction of ferrite in the broken specimens was measured by a ferrite scope. The volume fraction of martensitic transformation increased with an increase in the stress amplitude. These experimental results implied that the hydrogen-induced fatigue life degradation in the welded joint was closely related to the martensitic transformation during the fatigue process. The mechanisms of both the degradation in fatigue life and nondegradation in fatigue limit will be discussed further.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79203899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hideo Kobayashi, H. Kobayashi, Takeru Sano, T. Maeda, Hiroaki Tamura, Ayumu Ishizuka, M. Kimura, N. Yoshikawa, T. Iijima, J. Yamabe, S. Matsuoka, H. Matsunaga
In Japan, with regards to the widespread commercialization of 70 MPa-class hydrogen refueling stations and fuel cell vehicles, two national projects have been promoted on both the infrastructure and the automobile sides. These projects have been promoted to establish the criteria for determining hydrogen compatibility of materials and to expand the usable materials for high-pressure hydrogen environment. For these projects, establishing test methods to evaluate the hydrogen compatibility of materials is one of the most important tasks. This paper describes the status of common standardization of testing methods. Two projects share a common database for the testing results, which is currently put to practical use.
{"title":"Methods of Material Testing in High-Pressure Hydrogen Environment and Evaluation of Hydrogen Compatibility of Metallic Materials: Current Status in Japan","authors":"Hideo Kobayashi, H. Kobayashi, Takeru Sano, T. Maeda, Hiroaki Tamura, Ayumu Ishizuka, M. Kimura, N. Yoshikawa, T. Iijima, J. Yamabe, S. Matsuoka, H. Matsunaga","doi":"10.1115/PVP2018-84112","DOIUrl":"https://doi.org/10.1115/PVP2018-84112","url":null,"abstract":"In Japan, with regards to the widespread commercialization of 70 MPa-class hydrogen refueling stations and fuel cell vehicles, two national projects have been promoted on both the infrastructure and the automobile sides. These projects have been promoted to establish the criteria for determining hydrogen compatibility of materials and to expand the usable materials for high-pressure hydrogen environment. For these projects, establishing test methods to evaluate the hydrogen compatibility of materials is one of the most important tasks. This paper describes the status of common standardization of testing methods. Two projects share a common database for the testing results, which is currently put to practical use.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80627441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Austenitic stainless steel of the 300 series and their welds are widely employed in the production, storage and distribution infrastructures of gaseous and liquid hydrogen. However, hydrogen compatibility of their welds has not been completely understood, especially in high-pressure hydrogen environment. In this study, the influence of 98MPa high pressure gaseous hydrogen on the tensile properties and fracture behaviors of three kinds of S31603 weld joints were investigated, including SMAW, SAW and TIG welds. The tensile data indicated that hydrogen caused the ductility loss of the SAW and TIG weld joints, particularly for the TIG welds. For the SMAW weld joints, hydrogen had little impact on its ductility. Fractographic analysis revealed that hydrogen scarcely induced a change in the fracture mode of the SMAW welds. Different from this, the SAW and TIG welds were found to exhibit an obvious susceptibility to hydrogen embrittlement in this study, particularly for the TIG welds, based on the change of fracture features from dimples to facets, striations and secondary cracks. Additionally, both fracture surfaces of the SMAW and SAW welds contained some inclusions where the secondary cracks were promoted.
{"title":"Study on Hydrogen Compatibility of S31603 Weld Joints in 98MPa Gaseous Hydrogen","authors":"Qi He, Z. Hua, Jinyang Zheng","doi":"10.1115/PVP2018-84453","DOIUrl":"https://doi.org/10.1115/PVP2018-84453","url":null,"abstract":"Austenitic stainless steel of the 300 series and their welds are widely employed in the production, storage and distribution infrastructures of gaseous and liquid hydrogen. However, hydrogen compatibility of their welds has not been completely understood, especially in high-pressure hydrogen environment. In this study, the influence of 98MPa high pressure gaseous hydrogen on the tensile properties and fracture behaviors of three kinds of S31603 weld joints were investigated, including SMAW, SAW and TIG welds. The tensile data indicated that hydrogen caused the ductility loss of the SAW and TIG weld joints, particularly for the TIG welds. For the SMAW weld joints, hydrogen had little impact on its ductility. Fractographic analysis revealed that hydrogen scarcely induced a change in the fracture mode of the SMAW welds. Different from this, the SAW and TIG welds were found to exhibit an obvious susceptibility to hydrogen embrittlement in this study, particularly for the TIG welds, based on the change of fracture features from dimples to facets, striations and secondary cracks. Additionally, both fracture surfaces of the SMAW and SAW welds contained some inclusions where the secondary cracks were promoted.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74045395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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