Austenitic stainless steels are used extensively in hydrogen gas containment components due to their known resilience in hydrogen environments. Depending on the conditions, degradation can occur in austenitic stainless steels but typically the materials retain sufficient mechanical properties within such extreme environments. In many hydrogen containment applications, it is necessary or advantageous to join components through welding as it ensures minimal gas leakage, unlike mechanical fittings that can become leak paths that develop over time. Over the years many studies have focused on the mechanical behavior of austenitic stainless steels in hydrogen environments and determined their properties to be sufficient for most applications. However, significantly less data have been generated on austenitic stainless steel welds, which can exhibit more degradation than the base material. In this paper, we assess the trends observed in austenitic stainless steel welds tested in hydrogen. Experiments of welds including tensile and fracture toughness testing are assessed and comparisons to behavior of base metals are discussed.
{"title":"Evaluating the Resistance of Austenitic Stainless Steel Welds to Hydrogen Embrittlement","authors":"J. Ronevich, C. S. Marchi, D. Balch","doi":"10.1115/pvp2019-93823","DOIUrl":"https://doi.org/10.1115/pvp2019-93823","url":null,"abstract":"\u0000 Austenitic stainless steels are used extensively in hydrogen gas containment components due to their known resilience in hydrogen environments. Depending on the conditions, degradation can occur in austenitic stainless steels but typically the materials retain sufficient mechanical properties within such extreme environments. In many hydrogen containment applications, it is necessary or advantageous to join components through welding as it ensures minimal gas leakage, unlike mechanical fittings that can become leak paths that develop over time. Over the years many studies have focused on the mechanical behavior of austenitic stainless steels in hydrogen environments and determined their properties to be sufficient for most applications. However, significantly less data have been generated on austenitic stainless steel welds, which can exhibit more degradation than the base material. In this paper, we assess the trends observed in austenitic stainless steel welds tested in hydrogen. Experiments of welds including tensile and fracture toughness testing are assessed and comparisons to behavior of base metals are discussed.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73339366","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}
A single specimen technique to estimate crack length, standardized in ASTM E1820, is the so called load-normalization technique, also known as the Key-curve technique. The method is based on the separability between deformation and crack length. This means that if the load is normalized by a suitable function of crack length, the result will be a single crack length independent load-displacement curve. If this “Key”-curve is known, then based only on load and displacement information it is possible to estimate the corresponding crack length. The load normalizing method assumes a plastic response of the specimen during crack growth. If there is crack growth already in the elastic regime, non-linearity in the load-displacement record is not due to plasticity, but due to the crack growth. In this case the standard load-normalization method does not work since it assumes that the non-linearity is due to plasticity or crack tip blunting. Such materials require a modified approach. Here, a modified load normalization method accounting for possible elastic crack growth is presented. The method is shown to produce realistic crack growth estimates regardless of plasticity level of the specimen. The method applies an improved load normalization equation compared to the one presently used in ASTM E1820.
{"title":"Load Normalization Method Accounting for Elastic and Elastic-Plastic Crack Growth","authors":"K. Wallin, Steven X. Xu","doi":"10.1115/pvp2019-93226","DOIUrl":"https://doi.org/10.1115/pvp2019-93226","url":null,"abstract":"\u0000 A single specimen technique to estimate crack length, standardized in ASTM E1820, is the so called load-normalization technique, also known as the Key-curve technique. The method is based on the separability between deformation and crack length. This means that if the load is normalized by a suitable function of crack length, the result will be a single crack length independent load-displacement curve. If this “Key”-curve is known, then based only on load and displacement information it is possible to estimate the corresponding crack length.\u0000 The load normalizing method assumes a plastic response of the specimen during crack growth. If there is crack growth already in the elastic regime, non-linearity in the load-displacement record is not due to plasticity, but due to the crack growth. In this case the standard load-normalization method does not work since it assumes that the non-linearity is due to plasticity or crack tip blunting. Such materials require a modified approach.\u0000 Here, a modified load normalization method accounting for possible elastic crack growth is presented. The method is shown to produce realistic crack growth estimates regardless of plasticity level of the specimen. The method applies an improved load normalization equation compared to the one presently used in ASTM E1820.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74358258","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}
This work describes a local approach to cleavage fracture (LAF) incorporating the statistics of microcracks to characterize the cleavage fracture toughness distribution in structural steels. Fracture toughness testing conducted on standard compact tension C(T) specimens for a 22NiMoCr37 pressure vessel steel provides the cleavage fracture resistance data needed to determine the measured toughness distribution. Metallographic examination of etched surfaces for the tested steel also provides the distribution of carbides, which are assumed as the Griffith fracture-initiating particles, dispersed in the material from which the cleavage fracture toughness distribution is predicted. Overall, the analyses conducted in the present work show that LAFs incorporating the statistics of microcracks are a viable engineering procedure to describe the dependence of fracture toughness on temperature in the DBT region for ferritic steels.
{"title":"A Local Approach to Assess Temperature Effects on Fracture Toughness Incorporating the Measured Distribution of Microcracks","authors":"C. Ruggieri, A. Jivkov","doi":"10.1115/pvp2019-93186","DOIUrl":"https://doi.org/10.1115/pvp2019-93186","url":null,"abstract":"\u0000 This work describes a local approach to cleavage fracture (LAF) incorporating the statistics of microcracks to characterize the cleavage fracture toughness distribution in structural steels. Fracture toughness testing conducted on standard compact tension C(T) specimens for a 22NiMoCr37 pressure vessel steel provides the cleavage fracture resistance data needed to determine the measured toughness distribution. Metallographic examination of etched surfaces for the tested steel also provides the distribution of carbides, which are assumed as the Griffith fracture-initiating particles, dispersed in the material from which the cleavage fracture toughness distribution is predicted. Overall, the analyses conducted in the present work show that LAFs incorporating the statistics of microcracks are a viable engineering procedure to describe the dependence of fracture toughness on temperature in the DBT region for ferritic steels.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81927089","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}
The governor valve is a very important component in steam turbine, which can change the power output of the steam turbine by controlling the amount of the inlet steam. The service conditions of governor valve is very complicated, which should suffer high temperatures, high pressure, erosion, water induction and so on. As we all know the fatigue and creep can significantly reduce valve life. However, the damage due to governor valve seat interference fits is also very important for the units’ safety operation. A compromised interference fit can lead to significant valve leakage and possibly catastrophic seat failure. This article bases on a real case from a STP’s SC unit, which is operating in the South Asia market. Simulating the behavior of the valve seat under service conditions by numerical method, to find out the root cause of the interference fit failure and the operational advice for the unit running.
{"title":"Research on the Interference Fit of GV Seat Under the Service Load","authors":"Hu Yifeng, Sihua Xu, Chen Gang","doi":"10.1115/pvp2019-93304","DOIUrl":"https://doi.org/10.1115/pvp2019-93304","url":null,"abstract":"\u0000 The governor valve is a very important component in steam turbine, which can change the power output of the steam turbine by controlling the amount of the inlet steam. The service conditions of governor valve is very complicated, which should suffer high temperatures, high pressure, erosion, water induction and so on. As we all know the fatigue and creep can significantly reduce valve life. However, the damage due to governor valve seat interference fits is also very important for the units’ safety operation. A compromised interference fit can lead to significant valve leakage and possibly catastrophic seat failure. This article bases on a real case from a STP’s SC unit, which is operating in the South Asia market. Simulating the behavior of the valve seat under service conditions by numerical method, to find out the root cause of the interference fit failure and the operational advice for the unit running.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"8 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82954766","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}
A hydrogen manufacturing plant experienced circumferential cracking at the dissimilar weld on the outlet header. The outlet header was a cold wall design and the dissimilar weld was between HP40 modified and carbon ½ Mo steels. The resultant failure investigation found the cause to be hydrogen induced cracking of the dissimilar weld at the fusion boundary zone. The hydrogen was generated from the CO2 corrosion which occurred due to operating the tubes below the dew point and the hydrogen was trapped in the steel by the CO chemisorption onto the steel. The following paper outlines the failure investigation and the fitness for service conducted to maintain the running of the plant.
{"title":"Hydrogen Induced Cracking of a Dissimilar Weld in a Hydrogen Manufacturing Plant","authors":"N. Park, J. Penso","doi":"10.1115/pvp2019-93961","DOIUrl":"https://doi.org/10.1115/pvp2019-93961","url":null,"abstract":"\u0000 A hydrogen manufacturing plant experienced circumferential cracking at the dissimilar weld on the outlet header. The outlet header was a cold wall design and the dissimilar weld was between HP40 modified and carbon ½ Mo steels. The resultant failure investigation found the cause to be hydrogen induced cracking of the dissimilar weld at the fusion boundary zone. The hydrogen was generated from the CO2 corrosion which occurred due to operating the tubes below the dew point and the hydrogen was trapped in the steel by the CO chemisorption onto the steel. The following paper outlines the failure investigation and the fitness for service conducted to maintain the running of the plant.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"61 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85466372","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}
F. Brust, R. H. Dodds, J. Hobbs, B. Stoltz, D. Wells
NASA has hundreds of non-code layered pressure vessel (LPV) tanks that hold various gases at pressure. Many of the NASA tanks were fabricated in the 1950s and 1960s and are still in use. An agency wide effort is in progress to assess the fitness for continued service of these vessels. Layered tanks typically consist of an inner liner/shell (often about 12.5 mm thick) with different layers of thinner shells surrounding the inner liner each with thickness of about 6.25-mm. The layers serve as crack arrestors for crack growth through the thickness. The number of thinner layers required depends on the thickness required for the complete vessel with most tanks having between 4 and 20 layers. Cylindrical layers are welded longitudinally with staggering so that the weld heat affected zones do not overlap. The built-up shells are then circumferentially welded together or welded to a header to complete the tank construction. This paper presents some initial results which consider weld residual stress and fracture assessment of some layered pressure vessels and is a small part of the much larger fitness for service evaluation of these tanks. This effort considers the effect of weld residual stresses on fracture for an inner layer longitudinal weld. All fabrication steps are modeled, and the high-level proof testing of the vessels has an important effect on the final WRS state. Finally, cracks are introduced, and service loading applied to determine the effects of WRS on fracture.
{"title":"Weld Residual Stress and Fracture Behavior of NASA Layered Pressure Vessels","authors":"F. Brust, R. H. Dodds, J. Hobbs, B. Stoltz, D. Wells","doi":"10.1115/pvp2019-94021","DOIUrl":"https://doi.org/10.1115/pvp2019-94021","url":null,"abstract":"\u0000 NASA has hundreds of non-code layered pressure vessel (LPV) tanks that hold various gases at pressure. Many of the NASA tanks were fabricated in the 1950s and 1960s and are still in use. An agency wide effort is in progress to assess the fitness for continued service of these vessels. Layered tanks typically consist of an inner liner/shell (often about 12.5 mm thick) with different layers of thinner shells surrounding the inner liner each with thickness of about 6.25-mm. The layers serve as crack arrestors for crack growth through the thickness. The number of thinner layers required depends on the thickness required for the complete vessel with most tanks having between 4 and 20 layers. Cylindrical layers are welded longitudinally with staggering so that the weld heat affected zones do not overlap. The built-up shells are then circumferentially welded together or welded to a header to complete the tank construction. This paper presents some initial results which consider weld residual stress and fracture assessment of some layered pressure vessels and is a small part of the much larger fitness for service evaluation of these tanks. This effort considers the effect of weld residual stresses on fracture for an inner layer longitudinal weld. All fabrication steps are modeled, and the high-level proof testing of the vessels has an important effect on the final WRS state. Finally, cracks are introduced, and service loading applied to determine the effects of WRS on fracture.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83820784","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}
The dissimilar metal weld (DMW) is widely used in fabrication and manufacturing in various industries. Joining between nickel-based alloy and ferritic steel tubing and piping is commonly employed for ASME Code compliant welds for high-temperature and corrosion resistance applications. A series of DMW samples between alloy 600 pipe and SA-106 Grade B pipe are fabricated using different welding processes, joint design and welding techniques. By detailed comparison, this paper provides insight into the effects of these different welding variables on mechanical properties (tensile properties and hardness of weld materials and heat affected zone), metallurgical properties (macro and microstructure examination) and chemistry (root pass alloying dilution etc.) It has been shown that an asymmetric joint bevel design in consideration of different heat dissipation, melting temperature of the two materials will promote good weld bead formation during the root pass welding. Different joint designs (such as with or without consumable insert) will create variations on weld dilution and Cr/Ni recovery in the root area. Other welding variables such as tungsten electrode location for root pass welding for DMW, machine Gas Tungsten Arc Welding (GTAW) using hot wire and cold wire, etc. are also discussed.
{"title":"Effects of Welding Processes and Techniques on Mechanical and Metallurgical Properties of Dissimilar Metal Weld","authors":"D. Sun, Xinjian Duan","doi":"10.1115/pvp2019-93277","DOIUrl":"https://doi.org/10.1115/pvp2019-93277","url":null,"abstract":"\u0000 The dissimilar metal weld (DMW) is widely used in fabrication and manufacturing in various industries. Joining between nickel-based alloy and ferritic steel tubing and piping is commonly employed for ASME Code compliant welds for high-temperature and corrosion resistance applications.\u0000 A series of DMW samples between alloy 600 pipe and SA-106 Grade B pipe are fabricated using different welding processes, joint design and welding techniques. By detailed comparison, this paper provides insight into the effects of these different welding variables on mechanical properties (tensile properties and hardness of weld materials and heat affected zone), metallurgical properties (macro and microstructure examination) and chemistry (root pass alloying dilution etc.)\u0000 It has been shown that an asymmetric joint bevel design in consideration of different heat dissipation, melting temperature of the two materials will promote good weld bead formation during the root pass welding. Different joint designs (such as with or without consumable insert) will create variations on weld dilution and Cr/Ni recovery in the root area. Other welding variables such as tungsten electrode location for root pass welding for DMW, machine Gas Tungsten Arc Welding (GTAW) using hot wire and cold wire, etc. are also discussed.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80700363","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}
Stress rupture factors and weld strength reduction factors for Grade 91 steel weldments in the codes and literatures have been reviewed. Stress rupture factors for weld metals proposed for Code Case N-47 in the mid 1980’s was defined as a ratio of average rupture strength of the deposited filler metal to the average rupture strength of the base metal. Remarkable drop in creep rupture strength of weldments is significant issue of Grade 91, especially in the low-stress and long-term regime. A premature failure of Grade 91 steel weldments in the long-term, however, is caused by Type IV failure which takes place in the fine grain heat affected zone (FG-HAZ), rather than fracture in the deposited weld metal. The stress rupture factor of the Grade 91 steel, therefore, was based on the creep rupture strength of cross weld test specimens. Creep rupture data of Grade 91 steel weldments reported in the publication of ASME STP-PT-077 was incorporated in the creep database collected in Japan which was used for the previous study. Time and temperature dependent stress rupture factors for Grade 91 steel have been re-evaluated based on the extended database as a ratio of average creep rupture strength of cross weld test specimen to the average creep rupture strength of base metal.
对规范和文献中91级钢焊接件的应力断裂系数和焊接强度折减系数进行了综述。20世纪80年代中期，在Code Case N-47中提出了焊缝金属的应力断裂系数，定义为沉积的填充金属的平均断裂强度与母材的平均断裂强度之比。焊接件蠕变断裂强度的显著下降是91级的重要问题，特别是在低应力和长期状态下。然而，从长期来看，91级钢焊接件的过早失效是由IV型失效引起的，这种失效发生在细晶热影响区(FG-HAZ)，而不是在沉积的焊接金属中断裂。因此，91级钢的应力断裂系数基于交叉焊试件的蠕变断裂强度。ASME STP-PT-077出版物中报道的91级钢焊接件蠕变断裂数据被纳入日本收集的蠕变数据库，该数据库用于先前的研究。基于扩展的数据库，重新评估了91级钢与时间和温度相关的应力破裂系数，即交叉焊接试样的平均蠕变断裂强度与母材的平均蠕变断裂强度之比。
{"title":"Re-Evaluation of Stress Rupture Factors for Grade 91 Weldments Based on the Extended Database With the Data Collected in Japan","authors":"K. Kimura, M. Yaguchi","doi":"10.1115/pvp2019-93331","DOIUrl":"https://doi.org/10.1115/pvp2019-93331","url":null,"abstract":"\u0000 Stress rupture factors and weld strength reduction factors for Grade 91 steel weldments in the codes and literatures have been reviewed. Stress rupture factors for weld metals proposed for Code Case N-47 in the mid 1980’s was defined as a ratio of average rupture strength of the deposited filler metal to the average rupture strength of the base metal. Remarkable drop in creep rupture strength of weldments is significant issue of Grade 91, especially in the low-stress and long-term regime. A premature failure of Grade 91 steel weldments in the long-term, however, is caused by Type IV failure which takes place in the fine grain heat affected zone (FG-HAZ), rather than fracture in the deposited weld metal. The stress rupture factor of the Grade 91 steel, therefore, was based on the creep rupture strength of cross weld test specimens. Creep rupture data of Grade 91 steel weldments reported in the publication of ASME STP-PT-077 was incorporated in the creep database collected in Japan which was used for the previous study. Time and temperature dependent stress rupture factors for Grade 91 steel have been re-evaluated based on the extended database as a ratio of average creep rupture strength of cross weld test specimen to the average creep rupture strength of base metal.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83178868","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}
To construct advanced non-light water reactors (ANLWRs) operating in the temperature range above that for the traditional light water reactors (LWRs), Alloy 316H is one of the candidate materials because of its inexpensiveness, significant service experience, and qualification for nuclear applications by the American Society of Mechanical Engineers (ASME). However, during the life span at temperatures expected for the ANLWRs, the alloy is likely to experience thermal embrittlement that has not been a concern for the traditional LWRs. To prepare for the development, the possibility of adverse thermal embrittlement effects on Alloy 316H performance in the ANLWRs must be evaluated and a technical basis regarding thermal embrittlement, if necessary, must be established for structural integrity analysis to provide reasonable assurance of adequate nuclear safety protection. In this paper, current technical basis for nuclear applications of Alloy 316H deterioration from thermal aging is briefly introduced. The likelihood of adverse thermal embrittlement effects on Alloy 316H performance is evaluated through historical data on microstructural and mechanical property evolution. Characterization of thermal embrittlement is then discussed, followed by a review of predictive models and trend curves for alloy embrittlement. Based on the review and evaluation, technical gaps for addressing thermal embrittlement issues are identified and gap-filling actions are recommended for establishing a technical basis to enable adequate consideration of thermal embrittlement in Alloy 316H applications to the ANLWRs.
{"title":"Consideration of Thermal Embrittlement in Alloy 316H for Advanced Non-Light Water Reactor Applications","authors":"W. Ren, Lianshan Lin","doi":"10.1115/pvp2019-93431","DOIUrl":"https://doi.org/10.1115/pvp2019-93431","url":null,"abstract":"\u0000 To construct advanced non-light water reactors (ANLWRs) operating in the temperature range above that for the traditional light water reactors (LWRs), Alloy 316H is one of the candidate materials because of its inexpensiveness, significant service experience, and qualification for nuclear applications by the American Society of Mechanical Engineers (ASME). However, during the life span at temperatures expected for the ANLWRs, the alloy is likely to experience thermal embrittlement that has not been a concern for the traditional LWRs. To prepare for the development, the possibility of adverse thermal embrittlement effects on Alloy 316H performance in the ANLWRs must be evaluated and a technical basis regarding thermal embrittlement, if necessary, must be established for structural integrity analysis to provide reasonable assurance of adequate nuclear safety protection.\u0000 In this paper, current technical basis for nuclear applications of Alloy 316H deterioration from thermal aging is briefly introduced. The likelihood of adverse thermal embrittlement effects on Alloy 316H performance is evaluated through historical data on microstructural and mechanical property evolution. Characterization of thermal embrittlement is then discussed, followed by a review of predictive models and trend curves for alloy embrittlement. Based on the review and evaluation, technical gaps for addressing thermal embrittlement issues are identified and gap-filling actions are recommended for establishing a technical basis to enable adequate consideration of thermal embrittlement in Alloy 316H applications to the ANLWRs.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"105 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77736550","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}
This paper provides a technical basis for a crack growth rate (CGR) for use in performing evaluations of cracking in stainless steel canister materials. The source of crack initiation and growth is deposition of chloride aerosols on the canister surface followed by deliquescence leading to a brine solution. The brine solution attacks the stainless steel surface, leading to pitting; in the presence of tensile stress (such as residual tensile stress due to welding), stress corrosion cracking can occur. The CGR will be used for evaluating flaw growth under a proposed ASME Boiler and Pressure Vessel Code Case covering stainless steel canisters.
{"title":"Crack Growth Rate Model for CISCC of Stainless Steel Canisters","authors":"J. Broussard, C. Bryan, R. Sindelar, P. Lam","doi":"10.1115/pvp2019-94055","DOIUrl":"https://doi.org/10.1115/pvp2019-94055","url":null,"abstract":"\u0000 This paper provides a technical basis for a crack growth rate (CGR) for use in performing evaluations of cracking in stainless steel canister materials. The source of crack initiation and growth is deposition of chloride aerosols on the canister surface followed by deliquescence leading to a brine solution. The brine solution attacks the stainless steel surface, leading to pitting; in the presence of tensile stress (such as residual tensile stress due to welding), stress corrosion cracking can occur. The CGR will be used for evaluating flaw growth under a proposed ASME Boiler and Pressure Vessel Code Case covering stainless steel canisters.","PeriodicalId":23651,"journal":{"name":"Volume 6B: Materials and Fabrication","volume":"360 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82636646","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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