PSI - Issue 68

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ScienceDirect

Procedia Structural Integrity 68 (2025) 701–707 Structural Integrity Procedia 00 (2024) 000–000 Structural Integrity Procedia 00 (2024) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

European Conference on Fracture 2024 The stress field dependency of martensitic transformation in European Conference on Fracture 2024 The stress field dependency of martensitic transformation in

metastable austenitic stainless steel Ritsuki Morohoshi a, ∗ , Tomoya Kawabata a a Systems innovation, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan metastable austenitic stainless steel Ritsuki Morohoshi a, ∗ , Tomoya Kawabata a a Systems innovation, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers 10.1016/j.prostr.2025.06.118 ∗ Corresponding author. Tel.: +81-80-5000-4005. E-mail address: morohoshi@fract.t.u-tokyo.ac.jp 2210-7843 © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of ECF24 organizers. To address this, it is first necessary to outline the environmental conditions and challenges faced by large liquid hydrogen storage tank materials. Hydrogen causes embrittlement in steel materials, particularly those with a body-centered cubic (BCC) structure (de Melo Freire et al. (2024)). This phenomenon, known as hydrogen embrittlement (HE), remains insufficiently understood in terms of its mechanisms. To mitigate ∗ Corresponding author. Tel.: +81-80-5000-4005. E-mail address: morohoshi@fract.t.u-tokyo.ac.jp 2210-7843 © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of ECF24 organizers. Abstract Many large hydrogen storage tanks worldwide are constructed from metastable austenitic stainless steel; however, their fracture properties remain insufficiently understood. This is because the strain-induced martensitic transfor mation is dependent on stress triaxialities . The present study focuses on quantitatively evaluating the effect of different on the ′ transformation. This study firstly utilizes SEM-EBSD due to the high spatial resolution. Three ( ) different conditions were investigated. The results regenerated the dependency on ′ transfor mation. It also found out that the low condition somewhat suppressed the ′ transformation with large grain size. © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of ECF24 organizers. Keywords: Type your keywords here, separated by semicolons ; 1. Introduction In recent years, hydrogen has garnered attention as a carbon-neutral (CN) energy storage and electricity carrier. For example, it has been estimated that to achieve CN in Japan by 2050, hydrogen storage tanks, which are a key part of hydrogen infrastructure, must be scaled up by a factor of 20 compared to current models, with approximately six large-scale tanks needing to be constructed by 2030 (Tomoya (2023)). While the cost per unit volume generally decreases with scaling, in the case of liquid hydrogen storage tanks, the shift from high-pressure spherical designs to atmospheric-pressure flat-bottom cylindrical structures necessitates a renewed focus on fracture assessment. To address this, it is first necessary to outline the environmental conditions and challenges faced by large liquid hydrogen storage tank materials. Hydrogen causes embrittlement in steel materials, particularly those with a body-centered cubic (BCC) structure (de Melo Freire et al. (2024)). This phenomenon, known as hydrogen embrittlement (HE), remains insufficiently understood in terms of its mechanisms. To mitigate Abstract Many large hydrogen storage tanks worldwide are constructed from metastable austenitic stainless steel; however, their fracture properties remain insufficiently understood. This is because the strain-induced martensitic transfor mation is dependent on stress triaxialities . The present study focuses on quantitatively evaluating the effect of different on the ′ transformation. This study firstly utilizes SEM-EBSD due to the high spatial resolution. Three ( ) different conditions were investigated. The results regenerated the dependency on ′ transfor mation. It also found out that the low condition somewhat suppressed the ′ transformation with large grain size. © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of ECF24 organizers. Keywords: Type your keywords here, separated by semicolons ; 1. Introduction In recent years, hydrogen has garnered attention as a carbon-neutral (CN) energy storage and electricity carrier. For example, it has been estimated that to achieve CN in Japan by 2050, hydrogen storage tanks, which are a key part of hydrogen infrastructure, must be scaled up by a factor of 20 compared to current models, with approximately six large-scale tanks needing to be constructed by 2030 (Tomoya (2023)). While the cost per unit volume generally decreases with scaling, in the case of liquid hydrogen storage tanks, the shift from high-pressure spherical designs to atmospheric-pressure flat-bottom cylindrical structures necessitates a renewed focus on fracture assessment. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers