Ian Zuazo Rodriguez, Stefano Alberini, C. Bouillot, Dany Cornut, F. Fusari
9Cr-1Mo-V steel or Grade 91 has been typically used up to now in thermal power plants operating at high temperatures, e.g. 600°C. In another potential application, such as refinery equipment like hydrocracker and hydrotreater reactors, the choice is still the 2¼Cr-1Mo-¼V. The main reason is that the average design temperature of hydrocracker and hydrotreater reactors, approximately 450°C, has not been increased in the last 20 years making the use of 2¼Cr-1Mo-¼V steel more suitable and cheaper in comparison to Grade 91. However, some recent interest has been observed for its application in the petrochemical and chemical sector, including for new process technologies related to green economy market sectors. In these applications the influence of hydrogen could be detrimental for the steel and in the past, some investigations concluded positively on the use of Grade 91. In recent years, an improved control of the chemistry intended to improve creep properties has led to the industrial production of the SA-387 Grade 91 Type 2. Therefore, due to a renewed interest and an improved chemistry, tests were planned and carried out with the aim of assessing the hydrogen effect on the Grade 91 Type 2. This was done using welded test samples covering both full plate butt joints and weld overlays using two stainless steels, 308L and 347. In the butt joints, the impact transition curves of the weld metal, heat affected zone and base materials were compared to those after a heat treatment under high hydrogen pressure. The resistance to hydrogen induced disbonding was evaluated on the weld overlays. Finally, the influence of step cooling treatment on impact toughness was also investigated for both base and weld metal.
{"title":"Mechanical Properties and the Effect of Hydrogen on Base Metal and Welds of 9Cr-1Mo-V Steel","authors":"Ian Zuazo Rodriguez, Stefano Alberini, C. Bouillot, Dany Cornut, F. Fusari","doi":"10.1115/pvp2022-84862","DOIUrl":"https://doi.org/10.1115/pvp2022-84862","url":null,"abstract":"\u0000 9Cr-1Mo-V steel or Grade 91 has been typically used up to now in thermal power plants operating at high temperatures, e.g. 600°C. In another potential application, such as refinery equipment like hydrocracker and hydrotreater reactors, the choice is still the 2¼Cr-1Mo-¼V. The main reason is that the average design temperature of hydrocracker and hydrotreater reactors, approximately 450°C, has not been increased in the last 20 years making the use of 2¼Cr-1Mo-¼V steel more suitable and cheaper in comparison to Grade 91.\u0000 However, some recent interest has been observed for its application in the petrochemical and chemical sector, including for new process technologies related to green economy market sectors. In these applications the influence of hydrogen could be detrimental for the steel and in the past, some investigations concluded positively on the use of Grade 91. In recent years, an improved control of the chemistry intended to improve creep properties has led to the industrial production of the SA-387 Grade 91 Type 2.\u0000 Therefore, due to a renewed interest and an improved chemistry, tests were planned and carried out with the aim of assessing the hydrogen effect on the Grade 91 Type 2. This was done using welded test samples covering both full plate butt joints and weld overlays using two stainless steels, 308L and 347. In the butt joints, the impact transition curves of the weld metal, heat affected zone and base materials were compared to those after a heat treatment under high hydrogen pressure. The resistance to hydrogen induced disbonding was evaluated on the weld overlays. Finally, the influence of step cooling treatment on impact toughness was also investigated for both base and weld metal.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126104205","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}
When it comes to considering high-temperature damage mechanisms, one of the most challenging decisions is related to heavy-wall pressure vessels that operate at high pressure and high temperature in a hydrogen containing environment. Hydrotreatment or hydrocracking reactors typically fall under this category and often have an austenitic stainless-steel lining to protect the inner side of the pressure vessel from corrosion. Embrittlement of the carbon steel caused by High-Temperature Hydrogen Attack requires selecting steel with alloying elements such as Cr, Mo and V. The high risks of disbonding of the cladding interface under similar conditions also requires the selection of the most appropriate cladding technology. It is the upmost importance to ensure the interface will support the high-pressure hydrogen and the stresses generated by the heavily loaded internals. A study around characterizing the DetaClad™ interface was conducted under these extreme operating conditions. More than 150 tests were conducted and coming to the conclusion that DetaClad™ is appropriate for material selection under such demanding operating conditions.
{"title":"DetaClad™ Characterization for High-Temperature and High-Pressure Hydrogen Service","authors":"Olivier Sarrat, C. Prothe, T. Delahanty","doi":"10.1115/pvp2022-80639","DOIUrl":"https://doi.org/10.1115/pvp2022-80639","url":null,"abstract":"\u0000 When it comes to considering high-temperature damage mechanisms, one of the most challenging decisions is related to heavy-wall pressure vessels that operate at high pressure and high temperature in a hydrogen containing environment. Hydrotreatment or hydrocracking reactors typically fall under this category and often have an austenitic stainless-steel lining to protect the inner side of the pressure vessel from corrosion. Embrittlement of the carbon steel caused by High-Temperature Hydrogen Attack requires selecting steel with alloying elements such as Cr, Mo and V. The high risks of disbonding of the cladding interface under similar conditions also requires the selection of the most appropriate cladding technology. It is the upmost importance to ensure the interface will support the high-pressure hydrogen and the stresses generated by the heavily loaded internals.\u0000 A study around characterizing the DetaClad™ interface was conducted under these extreme operating conditions. More than 150 tests were conducted and coming to the conclusion that DetaClad™ is appropriate for material selection under such demanding operating conditions.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114507935","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}
Dong-Hyeon Kwak, J. Sim, Yoon-Suk Chang, B. Kong, C. Jang
Reactor vessel internals (RVIs) consist of austenitic stainless steels (ASSs) which have excellent material properties. Meanwhile, the high radiation environment of a reactor can cause the degradation of components. Since changed material properties are important for long-term operation, experimental researches related to tensile and fracture properties had been conducted. However, it is limited to investigate these researches due to their high radioactivity and small quantity. Thus recent researches have been dedicated to small specimens such as nanoindentation and micropillar compression tests and so on with ion-irradiation. In this study, micropillar compression tests were carried out for virgin and irradiated 304 ASSs to obtain microscopic mechanical behaviors. The trial sets of finite element (FE) analyses were performed to derive dislocation density based material constitutive equations for austenite phase by comparing with test results. Subsequently, representative volume elements analyses with periodic boundary conditions were adopted to estimate overall tensile stress-strain curves as well as 0.2% offset yield strengths (YSs) under the virgin and irradiated states. Finally, the effect of irradiated properties on typical RVIs were investigated. As typical results, optimized material parameters related to dislocation density based formulations were revealed, and microscopic stress-strain curves were reasonably comparable with test results. The estimated YS values were compared with the experimental results and corresponded within 9.09%. The overall deformation, stress and strain behaviors of typical RVIs were examined considering estimated properties, of which details and key findings will be discussed.
{"title":"Determination of Irradiated Stainless Steel Properties and Its Effects on Reactor Vessel Internals","authors":"Dong-Hyeon Kwak, J. Sim, Yoon-Suk Chang, B. Kong, C. Jang","doi":"10.1115/pvp2022-84936","DOIUrl":"https://doi.org/10.1115/pvp2022-84936","url":null,"abstract":"\u0000 Reactor vessel internals (RVIs) consist of austenitic stainless steels (ASSs) which have excellent material properties. Meanwhile, the high radiation environment of a reactor can cause the degradation of components. Since changed material properties are important for long-term operation, experimental researches related to tensile and fracture properties had been conducted. However, it is limited to investigate these researches due to their high radioactivity and small quantity. Thus recent researches have been dedicated to small specimens such as nanoindentation and micropillar compression tests and so on with ion-irradiation. In this study, micropillar compression tests were carried out for virgin and irradiated 304 ASSs to obtain microscopic mechanical behaviors. The trial sets of finite element (FE) analyses were performed to derive dislocation density based material constitutive equations for austenite phase by comparing with test results. Subsequently, representative volume elements analyses with periodic boundary conditions were adopted to estimate overall tensile stress-strain curves as well as 0.2% offset yield strengths (YSs) under the virgin and irradiated states. Finally, the effect of irradiated properties on typical RVIs were investigated. As typical results, optimized material parameters related to dislocation density based formulations were revealed, and microscopic stress-strain curves were reasonably comparable with test results. The estimated YS values were compared with the experimental results and corresponded within 9.09%. The overall deformation, stress and strain behaviors of typical RVIs were examined considering estimated properties, of which details and key findings will be discussed.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128284499","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. B. Rebak, E. Dolley, Wanming Zhang, R. Umretiya, A. Hoffman
Iron-chromium-aluminum (FeCrAl) alloys are being characterized to be used in light water reactors for the cladding of the fuel. This family of alloys were never used before in a reactor environment so their behavior should be evaluated. This manuscript describes the enhanced mechanical properties and thermal creep resistance of two FeCrAl alloys (PMC26M & FA-SMT or APMT-2) as compared with the current Zircaloy-2 based cladding. At 450°C and under a nominal hoop stress of 138 MPa (20ksi), Zircaloy-2 tubes suffer rapid creep while the two FeCrAl alloys do not show any evidence of creep at a higher nominal hoop stress of 324 MPa (47 ksi). FA-SMT had higher creep resistance than PMC26M at 600°C and 800°C mainly due to precipitate strengthening in FA-SMT.
{"title":"Enhanced Mechanical Properties of Iron-Chromium-Aluminum Cladding for Light Water Reactor Fuels","authors":"R. B. Rebak, E. Dolley, Wanming Zhang, R. Umretiya, A. Hoffman","doi":"10.1115/pvp2022-80557","DOIUrl":"https://doi.org/10.1115/pvp2022-80557","url":null,"abstract":"\u0000 Iron-chromium-aluminum (FeCrAl) alloys are being characterized to be used in light water reactors for the cladding of the fuel. This family of alloys were never used before in a reactor environment so their behavior should be evaluated. This manuscript describes the enhanced mechanical properties and thermal creep resistance of two FeCrAl alloys (PMC26M & FA-SMT or APMT-2) as compared with the current Zircaloy-2 based cladding. At 450°C and under a nominal hoop stress of 138 MPa (20ksi), Zircaloy-2 tubes suffer rapid creep while the two FeCrAl alloys do not show any evidence of creep at a higher nominal hoop stress of 324 MPa (47 ksi). FA-SMT had higher creep resistance than PMC26M at 600°C and 800°C mainly due to precipitate strengthening in FA-SMT.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130366202","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}
One of the biggest challenges in the design of an Floating Production Storage and Offloading (FPSO) plant is managing the weight of the facilities within the limited space and weight capacity of the ship. Weight reduction allows simplification of the load distribution on the ship, which is critical because the motions of the structure due to sea current and waves may affect the vessel performance. In this context, the use of high strength steels for pressure vessels reduces the weight by permitting thinner vessels and lighter supporting steel structures. Compared to ASME SA-516 Grade 70 steel, commonly used for pressure vessels, ASME SA-533 Class 2 steel provides approximately 30–50% greater allowable stress when vessels are designed in accordance with ASME Section VIII Division 1 or 2. Therefore, special considerations are needed to ensure sufficient impact toughness of the welds and to balance toughness, tensile and hardness properties required by the severe service condition. This paper aims at summarizing some technical data on high strength carbon steel SA-537 class 2 and low-alloy steel SA-533 type C class 2. A case study will illustrate the weight savings that can be achieved with these grades. In addition, characterization results obtained on base material from laboratory tests as well as welded joints will be provided, including hardness survey as regard to ANSI/NACE MR0175 / ISO 15156. Finally, a world-class manufacturer of pressure equipment will provide some feedback on the recent fabrication of pressure vessels in ASME SA-533 Type C grade for an offshore project in Western Africa. This contribution demonstrates the interest of high strength steels for the fabrication of lighter pressure vessels, and their potential use for severe conditions such as low-temperature or sour service.
{"title":"Low-Alloy SA-533 Steels as Alternative to ASME SA-516 Carbon Steel for Fabrication of Lightweight FPSO Vessels","authors":"Valéry Ngomo, E. Guyot, Ivan Lancini, Dany Cornut","doi":"10.1115/pvp2022-84672","DOIUrl":"https://doi.org/10.1115/pvp2022-84672","url":null,"abstract":"\u0000 One of the biggest challenges in the design of an Floating Production Storage and Offloading (FPSO) plant is managing the weight of the facilities within the limited space and weight capacity of the ship. Weight reduction allows simplification of the load distribution on the ship, which is critical because the motions of the structure due to sea current and waves may affect the vessel performance. In this context, the use of high strength steels for pressure vessels reduces the weight by permitting thinner vessels and lighter supporting steel structures.\u0000 Compared to ASME SA-516 Grade 70 steel, commonly used for pressure vessels, ASME SA-533 Class 2 steel provides approximately 30–50% greater allowable stress when vessels are designed in accordance with ASME Section VIII Division 1 or 2. Therefore, special considerations are needed to ensure sufficient impact toughness of the welds and to balance toughness, tensile and hardness properties required by the severe service condition.\u0000 This paper aims at summarizing some technical data on high strength carbon steel SA-537 class 2 and low-alloy steel SA-533 type C class 2. A case study will illustrate the weight savings that can be achieved with these grades. In addition, characterization results obtained on base material from laboratory tests as well as welded joints will be provided, including hardness survey as regard to ANSI/NACE MR0175 / ISO 15156. Finally, a world-class manufacturer of pressure equipment will provide some feedback on the recent fabrication of pressure vessels in ASME SA-533 Type C grade for an offshore project in Western Africa.\u0000 This contribution demonstrates the interest of high strength steels for the fabrication of lighter pressure vessels, and their potential use for severe conditions such as low-temperature or sour service.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125506995","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}
Baihui Xing, J. Wang, Haotian Wei, J. Shang, Z. Hua, C. Gu, Jinyang Zheng
Carburizing treatment can improve the carbon content of the workpiece material, and obtain higher contact fatigue strength, bending fatigue strength, as well as higher surface hardness. After carburizing, the existence of carbon atoms can hinder the adsorption and diffusion of hydrogen, thus reducing the hydrogen embrittlement. First-principles plane wave calculations based on spin-polarized density-functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption and permeation of hydrogen on iron in the bulk with carbon interstice solid solution and carbon substitution solid solution. Considering that hydrogen diffusion is faster in martensitic tissue, bcc-Fe structure is selected for the model. The results show that the hydrogen diffusion rate Di in the interstice solid solution is higher than Ds in the substitution solid solution. The formation of substitution solid solution is promoted by more vacancies in the lattice. When the vacancy is occupied by carbon atoms, the hydrogen diffusion rate is reduced. This phenomenon is more obvious for Fe48C16 structure with higher carbon ratio. Besides, charge density diagram and state density analysis are also consistent with this conclusion. Therefore, during carburizing, Increasing the content of carbon and carbon substituted solid solution can reduce the penetration of hydrogen in the material.
{"title":"Difference of Hydrogen Diffusion Regularity Between Interstice-Doped and Substitution-Doped Formed by Steel Carburizing","authors":"Baihui Xing, J. Wang, Haotian Wei, J. Shang, Z. Hua, C. Gu, Jinyang Zheng","doi":"10.1115/pvp2022-84462","DOIUrl":"https://doi.org/10.1115/pvp2022-84462","url":null,"abstract":"\u0000 Carburizing treatment can improve the carbon content of the workpiece material, and obtain higher contact fatigue strength, bending fatigue strength, as well as higher surface hardness. After carburizing, the existence of carbon atoms can hinder the adsorption and diffusion of hydrogen, thus reducing the hydrogen embrittlement. First-principles plane wave calculations based on spin-polarized density-functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption and permeation of hydrogen on iron in the bulk with carbon interstice solid solution and carbon substitution solid solution. Considering that hydrogen diffusion is faster in martensitic tissue, bcc-Fe structure is selected for the model. The results show that the hydrogen diffusion rate Di in the interstice solid solution is higher than Ds in the substitution solid solution. The formation of substitution solid solution is promoted by more vacancies in the lattice. When the vacancy is occupied by carbon atoms, the hydrogen diffusion rate is reduced. This phenomenon is more obvious for Fe48C16 structure with higher carbon ratio. Besides, charge density diagram and state density analysis are also consistent with this conclusion. Therefore, during carburizing, Increasing the content of carbon and carbon substituted solid solution can reduce the penetration of hydrogen in the material.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"242 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132622762","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. Kalyanam, Sushma Pothana, G. Wilkowski, Y. Hioe, F. Orth, F. Brust, S. Gilbert
Cold-working of elbows and other fittings results in higher strength of the material and has traditionally been considered to be beneficial for piping applications. Although it is known that cold-working leads to spatiotemporal variation in the grain size and the concomitant material property and fracture toughness variations they are not routinely investigated. Hence, this paper reports the findings from elbow fracture experiments conducted at 550°F and internal pressurized conditions (2,250 psi) on TP304 cold-worked elbows. The objectives for conducting the tests were to evaluate the effects of cold-working on the applicability of existing techniques such as an “Original” Net-Section-Collapse (NSC) and recently developed “Apparent NSC” equations for pipes with different inner diameter (ID) surface crack (SC) depths and lengths. This is to determine the failure moments and the plastic reduction factor (PRF) obtained to translate these to piping system evaluations. Preliminary comparisons of the experimental findings with the maximum stress predictions existing for straight pipes and elbow fracture prediction methods developed in the International Piping Integrity Research Group (IPIRG)-2 program were revisited, along with the verification of the applicability of the American Society of Mechanical Engineers (ASME) B2 stress indices and flaw acceptance criteria.
{"title":"Evaluation of the Fracture Behavior of Cold-Worked Elbows With Prescribed Cracks","authors":"S. Kalyanam, Sushma Pothana, G. Wilkowski, Y. Hioe, F. Orth, F. Brust, S. Gilbert","doi":"10.1115/pvp2022-84833","DOIUrl":"https://doi.org/10.1115/pvp2022-84833","url":null,"abstract":"\u0000 Cold-working of elbows and other fittings results in higher strength of the material and has traditionally been considered to be beneficial for piping applications. Although it is known that cold-working leads to spatiotemporal variation in the grain size and the concomitant material property and fracture toughness variations they are not routinely investigated. Hence, this paper reports the findings from elbow fracture experiments conducted at 550°F and internal pressurized conditions (2,250 psi) on TP304 cold-worked elbows. The objectives for conducting the tests were to evaluate the effects of cold-working on the applicability of existing techniques such as an “Original” Net-Section-Collapse (NSC) and recently developed “Apparent NSC” equations for pipes with different inner diameter (ID) surface crack (SC) depths and lengths. This is to determine the failure moments and the plastic reduction factor (PRF) obtained to translate these to piping system evaluations. Preliminary comparisons of the experimental findings with the maximum stress predictions existing for straight pipes and elbow fracture prediction methods developed in the International Piping Integrity Research Group (IPIRG)-2 program were revisited, along with the verification of the applicability of the American Society of Mechanical Engineers (ASME) B2 stress indices and flaw acceptance criteria.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"263 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131792044","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}
ASME Case N-888, Similar and Dissimilar Metal Welding Using Ambient Temperature SMAW and Machine GTAW Temper Bead Technique, requires a 48-hour hold time before nondestructive examination (NDE) can be performed to ensure hydrogen-induced cracking (HIC) did not occur. The aim of this work is to assess and characterize the HIC susceptibility of SA-508 pressure vessel steel. The results from this study will be used to consider potential elimination of the NDE hold time requirement in Case N-888. The Gleeble™ thermo-mechanical simulator was used to recreate CGHAZ for five weld conditions; as-welded, post-weld heat treated (PWHT), and four single-reheat temperatures of 675 °C, 700 °C, 725 °C, and 735 °C to simulate temper bead welding (TBW). Metallurgical characterization revealed a tempered martensitic microstructure for all TBW and the PWHT conditions. The 735 °C TBW sample developed ferrite along the prior austenite grain boundaries. The single reheats to 675 °C, 700 °C and 735 °C reduced the as-welded CGHAZ hardness from 425HV0.5 respectively to 313, 298, and 278HV0.5. A fourth TBW condition was added at 725 °C to eliminate ferrite formation seen at 735 °C. The TBW at 725 °C produced a microstructure of tempered martensite with a hardness of 298HV0.5. The HIC susceptibility is being evaluated using the Delayed Hydrogen Crack Test (DHCT) developed at the Ohio State University. Samples of SA-508 steel with the five CGHAZ microstructural conditions are loaded at 90% of the base metal yield strength and simultaneously electrolytically charged with hydrogen. The HIC susceptibility is ranked by the time to failure (full specimen separation) and sustained mechanical energy.
{"title":"Hydrogen Induced Cracking Susceptibility in the Heat Affected Zone of SA-508 Pressure Vessel Steel","authors":"Joshua D. Velasquez, B. Alexandrov, S. McCracken","doi":"10.1115/pvp2022-84781","DOIUrl":"https://doi.org/10.1115/pvp2022-84781","url":null,"abstract":"\u0000 ASME Case N-888, Similar and Dissimilar Metal Welding Using Ambient Temperature SMAW and Machine GTAW Temper Bead Technique, requires a 48-hour hold time before nondestructive examination (NDE) can be performed to ensure hydrogen-induced cracking (HIC) did not occur. The aim of this work is to assess and characterize the HIC susceptibility of SA-508 pressure vessel steel. The results from this study will be used to consider potential elimination of the NDE hold time requirement in Case N-888. The Gleeble™ thermo-mechanical simulator was used to recreate CGHAZ for five weld conditions; as-welded, post-weld heat treated (PWHT), and four single-reheat temperatures of 675 °C, 700 °C, 725 °C, and 735 °C to simulate temper bead welding (TBW). Metallurgical characterization revealed a tempered martensitic microstructure for all TBW and the PWHT conditions. The 735 °C TBW sample developed ferrite along the prior austenite grain boundaries. The single reheats to 675 °C, 700 °C and 735 °C reduced the as-welded CGHAZ hardness from 425HV0.5 respectively to 313, 298, and 278HV0.5. A fourth TBW condition was added at 725 °C to eliminate ferrite formation seen at 735 °C. The TBW at 725 °C produced a microstructure of tempered martensite with a hardness of 298HV0.5. The HIC susceptibility is being evaluated using the Delayed Hydrogen Crack Test (DHCT) developed at the Ohio State University. Samples of SA-508 steel with the five CGHAZ microstructural conditions are loaded at 90% of the base metal yield strength and simultaneously electrolytically charged with hydrogen. The HIC susceptibility is ranked by the time to failure (full specimen separation) and sustained mechanical energy.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"698 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122982920","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}
Xian-Kui Zhu, W. R. Johnson, R. Sindelar, B. Wiersma
Burst strength of line pipes is essential to pipeline design and integrity management. The simple Barlow equation with the ultimate tensile strength (UTS) was often used to estimate burst strength of line pipes. To consider the plastic flow effect of ductile steels, Zhu and Leis (2006, IJPVP) developed an average shear stress yield criterion and obtained the Zhu-Leis solution of burst strength for defect-free pipelines in term of UTS and strain hardening exponent, n, of materials. The Zhu-Leis solution was validated by more than 100 burst tests for various pipeline steels. The Zhu-Leis solution, when normalized by the Barlow strength, is a function of strain hardening rate, n, only, while the experimentally measured burst strength, when normalized by the Barlow strength, is a strong function of n and a weak function of UTS and pipe diameter to thickness ratio D/t. Due to difficulty of three-parameter regressions, this paper adopts the machine learning technology to develop alternative models of burst strength based on a large database of full-scale burst tests. In comparing to the regression, the machine learning method works well for both single and multiple parameters by introducing an artificial neural network (ANN), activation functions and learning algorithm for the network to learn and make predictions. Three ANN models were developed for predicting the burst strength of defect-free pipelines. Model 1 has one input variable and one hidden layer with three neurons; Model 2 has three input variables and one hidden layer with five neurons; and Model 3 has three input variables and two hidden layers with three neurons for the first hidden layer and two neurons for the second hidden layer. Those ANN models were then validated by the full-scale test data and evaluated through comparison with the Zhu-Leis solution and the linear regression result. On this basis, the best ANN model is recommended.
{"title":"Machine Learning Models of Burst Strength for Defect-Free Pipelines","authors":"Xian-Kui Zhu, W. R. Johnson, R. Sindelar, B. Wiersma","doi":"10.1115/pvp2022-84908","DOIUrl":"https://doi.org/10.1115/pvp2022-84908","url":null,"abstract":"\u0000 Burst strength of line pipes is essential to pipeline design and integrity management. The simple Barlow equation with the ultimate tensile strength (UTS) was often used to estimate burst strength of line pipes. To consider the plastic flow effect of ductile steels, Zhu and Leis (2006, IJPVP) developed an average shear stress yield criterion and obtained the Zhu-Leis solution of burst strength for defect-free pipelines in term of UTS and strain hardening exponent, n, of materials. The Zhu-Leis solution was validated by more than 100 burst tests for various pipeline steels.\u0000 The Zhu-Leis solution, when normalized by the Barlow strength, is a function of strain hardening rate, n, only, while the experimentally measured burst strength, when normalized by the Barlow strength, is a strong function of n and a weak function of UTS and pipe diameter to thickness ratio D/t. Due to difficulty of three-parameter regressions, this paper adopts the machine learning technology to develop alternative models of burst strength based on a large database of full-scale burst tests. In comparing to the regression, the machine learning method works well for both single and multiple parameters by introducing an artificial neural network (ANN), activation functions and learning algorithm for the network to learn and make predictions.\u0000 Three ANN models were developed for predicting the burst strength of defect-free pipelines. Model 1 has one input variable and one hidden layer with three neurons; Model 2 has three input variables and one hidden layer with five neurons; and Model 3 has three input variables and two hidden layers with three neurons for the first hidden layer and two neurons for the second hidden layer. Those ANN models were then validated by the full-scale test data and evaluated through comparison with the Zhu-Leis solution and the linear regression result. On this basis, the best ANN model is recommended.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128404713","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}
V. Robin, J. Draup, S. Hendili, J. Delmas, Q. Xiong, Mike C. Smith, Alexandre Paget
The mission of the European Network on Neutron Techniques Standardization for Structural Integrity (NeT) is to develop experimental and numerical techniques and standards for the reliable characterisation of residual stresses in structural welds. NeT was first established in 2002, and involves over 30 organisations from Europe and beyond. It operates on a “contribution in kind” basis from industrial, academic, and research facility partners. Each problem examined by the network is tackled by creating a dedicated Task Group (TG), which undertakes measurement and modelling studies and the interpretation of the results. NeT achieves this by conducting parallel measurement and prediction round robins on closely controlled and well characterized benchmark weldments. NeT TG8 follows on from the successful NeT TG1 and NeT TG4 benchmarks, which both examined welds in AISI 316L material and also NeT TG6 which examines an Alloy 600 plate containing a three pass “slot” weld made with Alloy 82 consumables. A new benchmark, NeT TG8, which examines an 18MnD5 (French nuclear code grade also named 18 MnNiMo 05) plate containing a five pass “slot” weld made with Alloy 52 consumables, has been organized to address welding repair issues. This paper describes the NeT TG8 benchmark as a whole, and presents preliminary materials characterization, residual stress measurement, and residual stress modelling results.
{"title":"NeT Project Task Group 8 – An International Benchmark on Residual Stress Assessment for Welding Repair","authors":"V. Robin, J. Draup, S. Hendili, J. Delmas, Q. Xiong, Mike C. Smith, Alexandre Paget","doi":"10.1115/pvp2022-85083","DOIUrl":"https://doi.org/10.1115/pvp2022-85083","url":null,"abstract":"\u0000 The mission of the European Network on Neutron Techniques Standardization for Structural Integrity (NeT) is to develop experimental and numerical techniques and standards for the reliable characterisation of residual stresses in structural welds. NeT was first established in 2002, and involves over 30 organisations from Europe and beyond. It operates on a “contribution in kind” basis from industrial, academic, and research facility partners. Each problem examined by the network is tackled by creating a dedicated Task Group (TG), which undertakes measurement and modelling studies and the interpretation of the results. NeT achieves this by conducting parallel measurement and prediction round robins on closely controlled and well characterized benchmark weldments. NeT TG8 follows on from the successful NeT TG1 and NeT TG4 benchmarks, which both examined welds in AISI 316L material and also NeT TG6 which examines an Alloy 600 plate containing a three pass “slot” weld made with Alloy 82 consumables. A new benchmark, NeT TG8, which examines an 18MnD5 (French nuclear code grade also named 18 MnNiMo 05) plate containing a five pass “slot” weld made with Alloy 52 consumables, has been organized to address welding repair issues. This paper describes the NeT TG8 benchmark as a whole, and presents preliminary materials characterization, residual stress measurement, and residual stress modelling results.","PeriodicalId":434862,"journal":{"name":"Volume 4B: Materials and Fabrication","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131937125","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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