Pub Date : 2026-02-01Epub Date: 2025-09-02DOI: 10.1016/j.ijpvp.2025.105634
Xiaoxiang Bai , Xaoxiao Wang , Haofeng Chen , Fuzhen Xuan , Guodong Jia
The hydrogenation reactor is one of the crucial pressure vessels in the petroleum refining and coal chemical industry, which is exposed to the complicated combinations of' elevated temperature environments, high-pressure conditions, and long creep dwell during service, resulting in the interaction between low-cycle fatigue (LCF) and creep. In this study, the extended Direct Steady Cyclic Analysis (eDSCA) procedure under the Linear Matching Method Framework (LMMF) is utilised to perform an in-depth analysis of the structural creep-fatigue behaviours of the hydrogenation reactors. The results indicate that as the stress-strain hysteresis curves evolve from closed to open states, there emerges a transition in the failure mechanism of the hydrogenation reactor from creep-fatigue to creep-ratcheting. Moreover, with increasing mechanical load and prolonged creep dwell time at loading points within the cyclic plastic zone, the location of maximum creep strain shifts from the outer wall to the inner wall of the nozzle, eventually migrating toward the junction between the nozzle and the vessel. The findings of this study facilitate understanding of the creep-fatigue failure in terms of pressure vessels and, hence, improve the accuracy of life prediction for hydrogenation reactors.
{"title":"Failure mechanisms transition of hydrogenation reactor: from creep-fatigue to creep-ratcheting","authors":"Xiaoxiang Bai , Xaoxiao Wang , Haofeng Chen , Fuzhen Xuan , Guodong Jia","doi":"10.1016/j.ijpvp.2025.105634","DOIUrl":"10.1016/j.ijpvp.2025.105634","url":null,"abstract":"<div><div>The hydrogenation reactor is one of the crucial pressure vessels in the petroleum refining and coal chemical industry, which is exposed to the complicated combinations of' elevated temperature environments, high-pressure conditions, and long creep dwell during service, resulting in the interaction between low-cycle fatigue (LCF) and creep. In this study, the extended Direct Steady Cyclic Analysis (eDSCA) procedure under the Linear Matching Method Framework (LMMF) is utilised to perform an in-depth analysis of the structural creep-fatigue behaviours of the hydrogenation reactors. The results indicate that as the stress-strain hysteresis curves evolve from closed to open states, there emerges a transition in the failure mechanism of the hydrogenation reactor from creep-fatigue to creep-ratcheting. Moreover, with increasing mechanical load and prolonged creep dwell time at loading points within the cyclic plastic zone, the location of maximum creep strain shifts from the outer wall to the inner wall of the nozzle, eventually migrating toward the junction between the nozzle and the vessel. The findings of this study facilitate understanding of the creep-fatigue failure in terms of pressure vessels and, hence, improve the accuracy of life prediction for hydrogenation reactors.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105634"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-09-06DOI: 10.1016/j.ijpvp.2025.105653
Yanyan Huang , Zizhen Yang , Jie Yang , Siyuan Zhang , Lingling Fan , Xuguang An , Lin Yang , Jianping Yang , Yang Guo
This study investigates the deterioration response of diverse micro-zones of dissimilar martensitic heat-resistant steel (F92/Co3W2) weldment to various service environments in ultra-supercritical (USC) thermal power unit, with respect to composition, microstructure and property evolution. The results indicate that temperature has the most significant effect on the corrosion damage rate, with severe corrosion intensification at 850 °C, where mass gain far exceeds that at 620 °C. The corrosion layer thickness shows a positive correlation with temperature, stress, or time increment, with temperature exhibiting a much greater impact than the other two factors. The F92 zone consistently exhibits more severe damage behavior than the weld metal and Co3W2 zones for any tested corrosion environment. It is found that martensitic heat-resistant steel exhibits a uniform damage (corrosion) propagation mode, with small cracks that lack obvious directionality, while Ni alloy 4169 shows a localized deepening damage pattern along grain boundaries perpendicular to the stress direction. Different welding zones demonstrate various local mechanical properties obtained by nanoindentation testing, which are analyzed based on the evolution of the microstructure, such as precipitates, dislocation density, etc., resulting from changes in service condition. Moreover, the Co3W2 zone demonstrates superior resistance to elastic strain damage and plastic deformation compared to the F92 and weld metal zones. This study provides a theoretical basis for understanding the damage mechanism with respect to microstructure and mechanical property evolution of dissimilar welded joints in elevated temperature service environments of ultra-supercritical units.
{"title":"Composition, microstructure and property evolution of diverse micro-zones of dissimilar weldment to various service environments in ultra-supercritical unit","authors":"Yanyan Huang , Zizhen Yang , Jie Yang , Siyuan Zhang , Lingling Fan , Xuguang An , Lin Yang , Jianping Yang , Yang Guo","doi":"10.1016/j.ijpvp.2025.105653","DOIUrl":"10.1016/j.ijpvp.2025.105653","url":null,"abstract":"<div><div>This study investigates the deterioration response of diverse micro-zones of dissimilar martensitic heat-resistant steel (F92/Co3W2) weldment to various service environments in ultra-supercritical (USC) thermal power unit, with respect to composition, microstructure and property evolution. The results indicate that temperature has the most significant effect on the corrosion damage rate, with severe corrosion intensification at 850 °C, where mass gain far exceeds that at 620 °C. The corrosion layer thickness shows a positive correlation with temperature, stress, or time increment, with temperature exhibiting a much greater impact than the other two factors. The F92 zone consistently exhibits more severe damage behavior than the weld metal and Co3W2 zones for any tested corrosion environment. It is found that martensitic heat-resistant steel exhibits a uniform damage (corrosion) propagation mode, with small cracks that lack obvious directionality, while Ni alloy 4169 shows a localized deepening damage pattern along grain boundaries perpendicular to the stress direction. Different welding zones demonstrate various local mechanical properties obtained by nanoindentation testing, which are analyzed based on the evolution of the microstructure, such as precipitates, dislocation density, etc., resulting from changes in service condition. Moreover, the Co3W2 zone demonstrates superior resistance to elastic strain damage and plastic deformation compared to the F92 and weld metal zones. This study provides a theoretical basis for understanding the damage mechanism with respect to microstructure and mechanical property evolution of dissimilar welded joints in elevated temperature service environments of ultra-supercritical units.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105653"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-10-31DOI: 10.1016/j.ijpvp.2025.105692
Fuchun Zhang , Jun Tu , Xin Shen , Lisha Peng , Grzegorz Tytko , Xiaochun Song
Submarine oil and gas pipelines are prone to various types of corrosive defects during service, posing serious threats to structural integrity and operational safety. In traditional non-destructive testing (NDT), defect classification primarily relies on manual expertise, which is inefficient and susceptible to subjective interference. To address these challenges, this paper proposes a novel automatic detection and grading method for corrosion defects based on a multi-sensory attention network (MSANet). A unidirectional surface wave electromagnetic acoustic transducer (EMAT) is developed to enable defect data acquisition and localization. The raw surface wave signals are processed using Short-Time Fourier Transform (STFT) and denoised through an integrated filtering technique. For the first time in this field, a wavelet attention mechanism (WAT) module is innovatively introduced to extract feature information in the wavelet domain. Furthermore, a heterogeneous branch collaborative attention (HBA) module is designed to simultaneously capture multi-scale and multi-level features while enhancing feature transmission through attention mechanisms. A feature fusion strategy is then employed to integrate the deep features extracted from both modules, forming a comprehensive defect discrimination model. The proposed method is validated on a constructed dataset, and experimental results demonstrate an average recognition accuracy of 97.52 %, significantly outperforming existing mainstream deep learning algorithm.
{"title":"MSANet: Electromagnetic ultrasonic signal recognition and grading of submarine pipeline defects based on a multi-sensory attention network","authors":"Fuchun Zhang , Jun Tu , Xin Shen , Lisha Peng , Grzegorz Tytko , Xiaochun Song","doi":"10.1016/j.ijpvp.2025.105692","DOIUrl":"10.1016/j.ijpvp.2025.105692","url":null,"abstract":"<div><div>Submarine oil and gas pipelines are prone to various types of corrosive defects during service, posing serious threats to structural integrity and operational safety. In traditional non-destructive testing (NDT), defect classification primarily relies on manual expertise, which is inefficient and susceptible to subjective interference. To address these challenges, this paper proposes a novel automatic detection and grading method for corrosion defects based on a multi-sensory attention network (MSANet). A unidirectional surface wave electromagnetic acoustic transducer (EMAT) is developed to enable defect data acquisition and localization. The raw surface wave signals are processed using Short-Time Fourier Transform (STFT) and denoised through an integrated filtering technique. For the first time in this field, a wavelet attention mechanism (WAT) module is innovatively introduced to extract feature information in the wavelet domain. Furthermore, a heterogeneous branch collaborative attention (HBA) module is designed to simultaneously capture multi-scale and multi-level features while enhancing feature transmission through attention mechanisms. A feature fusion strategy is then employed to integrate the deep features extracted from both modules, forming a comprehensive defect discrimination model. The proposed method is validated on a constructed dataset, and experimental results demonstrate an average recognition accuracy of 97.52 %, significantly outperforming existing mainstream deep learning algorithm.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105692"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-08-26DOI: 10.1016/j.ijpvp.2025.105625
Ahmed Reda , Ibrahim A. Sultan , Mohamed A. Shahin , Ali Karrech , Fokion Oikonomidis
The fatigue performance of seamless carbon steel pipelines is essential for maintaining structural integrity under cyclic loading. This study examines the effect of external surface imperfections on fatigue behavior, focusing on their role in crack initiation and propagation. Six full-scale fatigue tests were performed on seamless pipe specimens (276.1 mm outer diameter × 14.27 mm wall thickness), made of grade 450 carbon steel, compliant with DNV-ST-F101. Three specimens developed through-wall fatigue cracks that originated at external surface imperfections and propagated inwards. All three samples exceeded their target fatigue life, indicating that the imperfections were within allowable limits defined by the fatigue design curve. Metallurgical analysis showed that larger imperfections would likely have caused earlier crack initiation due to increased local stress. All pipes passed both mill and third-party inspection before testing. The results indicate that current inspection and quality control methods may not identify small imperfections that influence fatigue performance. A review of industry standards identified differences in surface defect limits, inspection techniques, and repair procedures. Proposed improvements include standardizing grinding limits, adopting automated non-destructive testing methods, and applying risk-based acceptance criteria. These measures aim to improve fatigue resistance and support consistent pipeline integrity management.
碳钢无缝管道的疲劳性能是保证管道在循环荷载作用下结构完整性的关键。本研究考察了外表面缺陷对疲劳行为的影响，重点研究了它们在裂纹萌生和扩展中的作用。采用DNV-ST-F101标准的450级碳钢无缝管试样（外径276.1 mm ×壁厚14.27 mm）进行了6次全尺寸疲劳试验。三个试件出现了从外表面缺陷开始并向内扩展的穿壁疲劳裂纹。三个试样均超过了目标疲劳寿命，表明缺陷在疲劳设计曲线规定的允许范围内。金相分析表明，由于局部应力的增加，较大的缺陷可能会导致更早的裂纹萌生。所有管道在测试前都通过了工厂和第三方的检验。结果表明，现有的检测和质量控制方法可能无法识别影响疲劳性能的小缺陷。对工业标准的回顾确定了表面缺陷限制、检查技术和修复程序的差异。建议的改进包括标准化磨削限制，采用自动化无损检测方法，以及应用基于风险的验收标准。这些措施旨在提高管道的抗疲劳性，支持管道完整性的一致性管理。
{"title":"Fatigue analysis and structural integrity of seamless carbon steel pipelines: Insights from surface imperfections to industry standards","authors":"Ahmed Reda , Ibrahim A. Sultan , Mohamed A. Shahin , Ali Karrech , Fokion Oikonomidis","doi":"10.1016/j.ijpvp.2025.105625","DOIUrl":"10.1016/j.ijpvp.2025.105625","url":null,"abstract":"<div><div>The fatigue performance of seamless carbon steel pipelines is essential for maintaining structural integrity under cyclic loading. This study examines the effect of external surface imperfections on fatigue behavior, focusing on their role in crack initiation and propagation. Six full-scale fatigue tests were performed on seamless pipe specimens (276.1 mm outer diameter × 14.27 mm wall thickness), made of grade 450 carbon steel, compliant with DNV-ST-F101. Three specimens developed through-wall fatigue cracks that originated at external surface imperfections and propagated inwards. All three samples exceeded their target fatigue life, indicating that the imperfections were within allowable limits defined by the fatigue design curve. Metallurgical analysis showed that larger imperfections would likely have caused earlier crack initiation due to increased local stress. All pipes passed both mill and third-party inspection before testing. The results indicate that current inspection and quality control methods may not identify small imperfections that influence fatigue performance. A review of industry standards identified differences in surface defect limits, inspection techniques, and repair procedures. Proposed improvements include standardizing grinding limits, adopting automated non-destructive testing methods, and applying risk-based acceptance criteria. These measures aim to improve fatigue resistance and support consistent pipeline integrity management.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105625"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-09-17DOI: 10.1016/j.ijpvp.2025.105660
Abdel-Hakim Bouzid, Mohammad Choulaei
Bolted flange joints are favored across a spectrum of pressure vessel applications within diverse industries, owing to their simplicity in installation and operation. However, ensuring their structural integrity and leak-proof performance necessitates careful consideration of both operational conditions and the nature of the connected shell. Yet, the existing ASME BPV Code for flange design lacks inclusion of a leakage criterion or flexibility analysis, hindering accurate assessment of these critical characteristics.
This research aims to comprehensively evaluate the integrity and leakage resilience of various shell configurations attached to flange rings. The investigation will scrutinize pivotal factors such as flange rotation and stress distribution at the flange-shell interface, leveraging diverse shell theories across three distinct flange sizes: NPS 26, 48, and 60. Additionally, four prevalent types of shell connections—cylindrical, spherical, dish, and conical—will be juxtaposed. Notably, all shell connections are directly affixed to the raised-face flange ring. To facilitate comparison and validation, these shell connections will be simulated using a versatile finite element program, augmenting the analytical approach. Noteworthy is the incorporation of the gasket's nonlinear behavior in the finite element analysis, a crucial aspect overlooked in the analytical modeling process.
{"title":"Comparison of Stresses in the Junctions of Shell Structures with Bolted Flange Rings","authors":"Abdel-Hakim Bouzid, Mohammad Choulaei","doi":"10.1016/j.ijpvp.2025.105660","DOIUrl":"10.1016/j.ijpvp.2025.105660","url":null,"abstract":"<div><div>Bolted flange joints are favored across a spectrum of pressure vessel applications within diverse industries, owing to their simplicity in installation and operation. However, ensuring their structural integrity and leak-proof performance necessitates careful consideration of both operational conditions and the nature of the connected shell. Yet, the existing ASME BPV Code for flange design lacks inclusion of a leakage criterion or flexibility analysis, hindering accurate assessment of these critical characteristics.</div><div>This research aims to comprehensively evaluate the integrity and leakage resilience of various shell configurations attached to flange rings. The investigation will scrutinize pivotal factors such as flange rotation and stress distribution at the flange-shell interface, leveraging diverse shell theories across three distinct flange sizes: NPS 26, 48, and 60. Additionally, four prevalent types of shell connections—cylindrical, spherical, dish, and conical—will be juxtaposed. Notably, all shell connections are directly affixed to the raised-face flange ring. To facilitate comparison and validation, these shell connections will be simulated using a versatile finite element program, augmenting the analytical approach. Noteworthy is the incorporation of the gasket's nonlinear behavior in the finite element analysis, a crucial aspect overlooked in the analytical modeling process.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105660"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-10-12DOI: 10.1016/j.ijpvp.2025.105683
Yihua Li, Xiaoting Gu
CO2 readily corrodes the inner wall of pipe bends during transport, significantly affecting the safe operation of the pipeline. Presently, the majority of research solely examines the corrosion of bends by a singular mechanism, neglecting the effects of various physical field interactions. In practical working situations, bends induce many mechanical stress actions and electrochemical responses, potentially resulting in a more complex scenario. Consequently, for the X80 pipeline, a mechanical-electrical coupling corrosion model for CO2 transport bends was developed to examine the corrosion behaviour of CO2 on the bend under various physical fields, including velocity and pressure fields. The sensitivity of parameters such as inlet flow rate, bending angle, and radius of curvature was analysed, culminating in the establishment of a corrosion prediction model. The findings indicate that corrosion in the bend section exceeds that in the straight section, with internal corrosion in the bend being greater than external corrosion. As the inlet flow rate increases, the corrosion rate accelerates, but the acceleration rate diminishes after reaching 2 m/s. Additionally, as the radius of curvature and bending angle increase, the corrosion rate progressively decreases, slowing after reaching 2D and 70°, respectively; therefore, it is recommended to select a pipe with a curvature radius greater than 2D. On-site workers may also determine suitable bend parameters according to pertinent contour maps. The study's results can enhance the optimisation of CO2 transport process parameters and bend selection, hence improving safety performance and extending the service life of the bends.
{"title":"Simulation of CO2 corrosion and prediction model for corrosion rate based on mechanical-electrical interaction in pipe bends","authors":"Yihua Li, Xiaoting Gu","doi":"10.1016/j.ijpvp.2025.105683","DOIUrl":"10.1016/j.ijpvp.2025.105683","url":null,"abstract":"<div><div>CO<sub>2</sub> readily corrodes the inner wall of pipe bends during transport, significantly affecting the safe operation of the pipeline. Presently, the majority of research solely examines the corrosion of bends by a singular mechanism, neglecting the effects of various physical field interactions. In practical working situations, bends induce many mechanical stress actions and electrochemical responses, potentially resulting in a more complex scenario. Consequently, for the X80 pipeline, a mechanical-electrical coupling corrosion model for CO<sub>2</sub> transport bends was developed to examine the corrosion behaviour of CO<sub>2</sub> on the bend under various physical fields, including velocity and pressure fields. The sensitivity of parameters such as inlet flow rate, bending angle, and radius of curvature was analysed, culminating in the establishment of a corrosion prediction model. The findings indicate that corrosion in the bend section exceeds that in the straight section, with internal corrosion in the bend being greater than external corrosion. As the inlet flow rate increases, the corrosion rate accelerates, but the acceleration rate diminishes after reaching 2 m/s. Additionally, as the radius of curvature and bending angle increase, the corrosion rate progressively decreases, slowing after reaching 2D and 70°, respectively; therefore, it is recommended to select a pipe with a curvature radius greater than 2D. On-site workers may also determine suitable bend parameters according to pertinent contour maps. The study's results can enhance the optimisation of CO<sub>2</sub> transport process parameters and bend selection, hence improving safety performance and extending the service life of the bends.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105683"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-04DOI: 10.1016/j.ijpvp.2025.105697
Sue-Ray Lin, Hsien-Chou Lin, Chin-Cheng Huang
During the transitional phase of a nuclear power plant's decommissioning process, prior to the removal of spent nuclear fuel from the spent fuel pool, certain key retained equipment—such as passive components like heat exchangers in the spent fuel pool cooling system—is expected to maintain its required functional performance even after the expiration of the operating license. According to a 2023 fatigue assessment report by the International Atomic Energy Agency (IAEA), heat exchanger tubes may experience wear due to vibration and relative motion with support plates, and fouling can also lead to a reduction in heat transfer capacity. Additionally, the plant's maintenance procedure manual specify that detailed disassembly and inspection of heat exchangers are generally performed only when there is evidence of reduced heat exchange performance or increased inlet-outlet pressure differentials. However, during this phase, as the equipment continues to operate, inlet-outlet pressure differentials remain the primary diagnostic criterion.
This study uses computational fluid dynamics (CFD) simulations to model fluid behavior within heat exchanger tubes under hypothetical fouling conditions. Based on the findings, it is recommended that, even though the heat exchange functionality is no longer critical during the transitional phase, potential future degradation caused by fouling cannot be accurately assessed solely based on pressure differentials. Regular detailed disassembly and inspections are necessary to ensure the equipment's functional performance remains reliable beyond its design life, particularly in preventing potential leakage issues.
{"title":"A study on the maintenance and management mechanisms of heat exchangers in spent fuel pool systems during nuclear facility decommissioning transition","authors":"Sue-Ray Lin, Hsien-Chou Lin, Chin-Cheng Huang","doi":"10.1016/j.ijpvp.2025.105697","DOIUrl":"10.1016/j.ijpvp.2025.105697","url":null,"abstract":"<div><div>During the transitional phase of a nuclear power plant's decommissioning process, prior to the removal of spent nuclear fuel from the spent fuel pool, certain key retained equipment—such as passive components like heat exchangers in the spent fuel pool cooling system—is expected to maintain its required functional performance even after the expiration of the operating license. According to a 2023 fatigue assessment report by the International Atomic Energy Agency (IAEA), heat exchanger tubes may experience wear due to vibration and relative motion with support plates, and fouling can also lead to a reduction in heat transfer capacity. Additionally, the plant's maintenance procedure manual specify that detailed disassembly and inspection of heat exchangers are generally performed only when there is evidence of reduced heat exchange performance or increased inlet-outlet pressure differentials. However, during this phase, as the equipment continues to operate, inlet-outlet pressure differentials remain the primary diagnostic criterion.</div><div>This study uses computational fluid dynamics (CFD) simulations to model fluid behavior within heat exchanger tubes under hypothetical fouling conditions. Based on the findings, it is recommended that, even though the heat exchange functionality is no longer critical during the transitional phase, potential future degradation caused by fouling cannot be accurately assessed solely based on pressure differentials. Regular detailed disassembly and inspections are necessary to ensure the equipment's functional performance remains reliable beyond its design life, particularly in preventing potential leakage issues.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105697"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-09-18DOI: 10.1016/j.ijpvp.2025.105656
Lei Hu , Kaizhe Zhang , Lin Yuan
Owing to its outstanding creep strength and corrosion durability, P92 steel has become an indispensable material for high temperature components of ultra-supercritical power units. Postweld heat treatment (PWHT) is required to stabilize the microstructure and improve the toughness of weld joints. The coarse-grained heat-affected zone (CGHAZ) is the most brittle fracture-prone region in welded joints due to its low fracture toughness. In this study, the welding thermal simulation method was used to prepare the microstructure of CGHAZ in P92 steel welded joints, and the effect of tempering parameters on the microstructure and mechanical properties were systematically investigated. The results indicated that PWHT promoted the precipitation of secondary phases, and the precipitates progressively coarsen with increasing tempering parameters. Meanwhile, the hardness was significantly decreased and the impact toughness was concurrently improved. The prediction model based on the P-parameter and λ-parameter methods were employed to quantify the relationship among tempering temperature, time, and mechanical properties. Based on prediction model and comprehensive assessment of the synergistic variations in impact toughness, hardness, and tensile strength, the optimal tempering P-parameter of P92 steel is determined to be 20.97–21.47 and the corresponding tempering parameters are 760 °C × (2–6) h. The corresponding hardness was 199–211 HV, the impact absorption energy was 103–113 J, and the tensile strength was 576–610 MPa.
{"title":"Effect of postweld heat treatment on microstructure and mechanical properties of simulated coarse grain heat-affected zone in P92 heat-resistant steel","authors":"Lei Hu , Kaizhe Zhang , Lin Yuan","doi":"10.1016/j.ijpvp.2025.105656","DOIUrl":"10.1016/j.ijpvp.2025.105656","url":null,"abstract":"<div><div>Owing to its outstanding creep strength and corrosion durability, P92 steel has become an indispensable material for high temperature components of ultra-supercritical power units. Postweld heat treatment (PWHT) is required to stabilize the microstructure and improve the toughness of weld joints. The coarse-grained heat-affected zone (CGHAZ) is the most brittle fracture-prone region in welded joints due to its low fracture toughness. In this study, the welding thermal simulation method was used to prepare the microstructure of CGHAZ in P92 steel welded joints, and the effect of tempering parameters on the microstructure and mechanical properties were systematically investigated. The results indicated that PWHT promoted the precipitation of secondary phases, and the precipitates progressively coarsen with increasing tempering parameters. Meanwhile, the hardness was significantly decreased and the impact toughness was concurrently improved. The prediction model based on the <em>P</em>-parameter and <em>λ</em>-parameter methods were employed to quantify the relationship among tempering temperature, time, and mechanical properties. Based on prediction model and comprehensive assessment of the synergistic variations in impact toughness, hardness, and tensile strength, the optimal tempering <em>P</em>-parameter of P92 steel is determined to be 20.97–21.47 and the corresponding tempering parameters are 760 °C × (2–6) h. The corresponding hardness was 199–211 HV, the impact absorption energy was 103–113 J, and the tensile strength was 576–610 MPa.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105656"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-10-07DOI: 10.1016/j.ijpvp.2025.105677
Lipeng Cai , Lei Zhao , Kai Song , Lianyong Xu , Yongdian Han , Kangda Hao , Qingfeng Wang , Derui Guo
To ensure safe and reliable operation of high-temperature power plant components, it is crucial to evaluate the failure risk of P92 steel welded joints after long-term service. This study systematically investigated microstructural evolution and creep damage mechanisms using a multi technique characterization approach to analyze weld metal (WM), coarse grained heat-affected zone (CGHAZ), fine grained heat-affected zone (FGHAZ), and base metal (BM). Results revealed pronounced softening in the FGHAZ, with microhardness declining to 175 HV10, while repair welding partially restored microstructure and hardness in WM and CGHAZ. Degradation in FGHAZ, including precipitate coarsening and lath structure loss, remained largely irreversible. Creep cavities preferentially nucleated at δ-ferrite, grain boundary triple junctions, and coarse M23C6 and Laves phases. TEM observations showed extensive dislocation entanglement and slip around coarse precipitates, facilitating microcrack initiation, whereas MX carbonitrides remained stable. EBSD analysis indicated severe microstructural degradation in FGHAZ, with reduced lath boundaries and kernel average misorientation, and increased fractions of recrystallized grains and subgrains, contributing to localized softening and elevated creep susceptibility. Based on these findings, a creep damage model governed by microstructural degradation and abnormal δ-ferrite distribution was proposed. Overall, the study identified δ-ferrite and coarse precipitates as primary damage nucleation sites, providing quantitative microstructural metrics to guide failure risk assessment and life prediction of P92 welded joints after long-term service.
{"title":"Microstructural evolution, creep damage mechanism and failure risk of P92 steel welded joints after long-term service","authors":"Lipeng Cai , Lei Zhao , Kai Song , Lianyong Xu , Yongdian Han , Kangda Hao , Qingfeng Wang , Derui Guo","doi":"10.1016/j.ijpvp.2025.105677","DOIUrl":"10.1016/j.ijpvp.2025.105677","url":null,"abstract":"<div><div>To ensure safe and reliable operation of high-temperature power plant components, it is crucial to evaluate the failure risk of P92 steel welded joints after long-term service. This study systematically investigated microstructural evolution and creep damage mechanisms using a multi technique characterization approach to analyze weld metal (WM), coarse grained heat-affected zone (CGHAZ), fine grained heat-affected zone (FGHAZ), and base metal (BM). Results revealed pronounced softening in the FGHAZ, with microhardness declining to 175 HV10, while repair welding partially restored microstructure and hardness in WM and CGHAZ. Degradation in FGHAZ, including precipitate coarsening and lath structure loss, remained largely irreversible. Creep cavities preferentially nucleated at δ-ferrite, grain boundary triple junctions, and coarse M<sub>23</sub>C<sub>6</sub> and Laves phases. TEM observations showed extensive dislocation entanglement and slip around coarse precipitates, facilitating microcrack initiation, whereas MX carbonitrides remained stable. EBSD analysis indicated severe microstructural degradation in FGHAZ, with reduced lath boundaries and kernel average misorientation, and increased fractions of recrystallized grains and subgrains, contributing to localized softening and elevated creep susceptibility. Based on these findings, a creep damage model governed by microstructural degradation and abnormal δ-ferrite distribution was proposed. Overall, the study identified δ-ferrite and coarse precipitates as primary damage nucleation sites, providing quantitative microstructural metrics to guide failure risk assessment and life prediction of P92 welded joints after long-term service.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105677"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-09-23DOI: 10.1016/j.ijpvp.2025.105661
Harleen Kaur Sandhu , William Ashe , Nicholas Crowder , Abhinav Gupta , Kevin Han , Saran Srikanth Bodda
Design changes during the construction phase of nuclear power plants can lead to significant financial expenses and delays in the project schedule, largely due to the complex regulatory and safety requirements specific to nuclear facilities. Effective communication and management of these changes with all involved parties to assess the associated risks effectively can potentially prevent cost overruns and delays. Enhancing the interoperability between building information modeling (BIM) and finite element (FE) analysis software can mitigate the impacts of redesign through efficient communication between design and construction teams. This improvement involves creating an FE model for structural elements or mechanical piping systems based on BIM’s building data. Accurate identification of the geometric location and section properties of BIM elements is essential for precise FE model development. Hence, this study provides an overview of an interoperability interface program between BIM and FEM, facilitating the seamless integration of efforts by design and construction engineers to ensure alignment across different project components. The extracted structural properties are utilized to generate accurate geometric and structural FE models in ANSYS Mechanical APDL. Prior to approving design changes due to construction constraints, a thorough structural analysis must be conducted. This research explores automated structural analysis of nuclear systems using an updated FEM model, emphasizing standardized interfaces for software communication. Improved interoperability and automated FE analysis not only enhance the flow of critical information between design and construction engineers but also provide a basis for risk-informed construction management, enhancing both safety and efficiency in nuclear power plant construction.
{"title":"Automation in digital analysis solutions for nuclear design-construction integration using BIM-FEM interoperability","authors":"Harleen Kaur Sandhu , William Ashe , Nicholas Crowder , Abhinav Gupta , Kevin Han , Saran Srikanth Bodda","doi":"10.1016/j.ijpvp.2025.105661","DOIUrl":"10.1016/j.ijpvp.2025.105661","url":null,"abstract":"<div><div>Design changes during the construction phase of nuclear power plants can lead to significant financial expenses and delays in the project schedule, largely due to the complex regulatory and safety requirements specific to nuclear facilities. Effective communication and management of these changes with all involved parties to assess the associated risks effectively can potentially prevent cost overruns and delays. Enhancing the interoperability between building information modeling (BIM) and finite element (FE) analysis software can mitigate the impacts of redesign through efficient communication between design and construction teams. This improvement involves creating an FE model for structural elements or mechanical piping systems based on BIM’s building data. Accurate identification of the geometric location and section properties of BIM elements is essential for precise FE model development. Hence, this study provides an overview of an interoperability interface program between BIM and FEM, facilitating the seamless integration of efforts by design and construction engineers to ensure alignment across different project components. The extracted structural properties are utilized to generate accurate geometric and structural FE models in ANSYS Mechanical APDL. Prior to approving design changes due to construction constraints, a thorough structural analysis must be conducted. This research explores automated structural analysis of nuclear systems using an updated FEM model, emphasizing standardized interfaces for software communication. Improved interoperability and automated FE analysis not only enhance the flow of critical information between design and construction engineers but also provide a basis for risk-informed construction management, enhancing both safety and efficiency in nuclear power plant construction.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":"219 ","pages":"Article 105661"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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