PSI - Issue 59

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Procedia Structural Integrity 00 (2024) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Procedia Structural Integrity 00 (2024) 000 – 000

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Procedia Structural Integrity 59 (2024) 137–144

© 2024 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 DMDP 2023 Organizers © 2024 The Auth ors. 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 DMDP 2023 Organizers Keywords: cracked specimen; fatigue pre-cracking; slow strain rate testing (SSRT); numerical modeling; stress-and-strain assisted diffusion of hydrogen; hydrostatic stress; plastic strain; hydrogen concentration. Abstract Crack tip hydrogen diffusion assisted by stress and strain fields is analysed in this paper, together with its role and implications in hydrogen assisted cracking (HAC). To this end, and firstly , a wide experimental programme was taken into account, consisting of slow strain rate tests (SSRT) on high-strength pearlitic steel rods under cathodic electrochemical conditions promoting HAC, considering the maximum stress intensity factor (SIF K max ) during fatigue pre-cracking as the relevant test variable, so as to consider the cyclic pre-loading history as the key factor in the further evolution of HAC. In addition, and secondly , a numerical analysis was performed of the effect of cyclic pre-loading regime on the posterior HAC behaviour of high-strength steel, considering both mechanical aspects (mechanical modelling: evolution of near-tip stress-strain fields) and chemical issues (hydrogen diffusion modelling: evolution on near-tip hydrogen concentration distributions). Results show clearly that hydrogen accumulation in prospective fracture sites depends on residual stress distributions produced by cyclic pre-loading. © 2024 The Auth ors. 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 DMDP 2023 Organizers Keywords: cracked specimen; fatigue pre-cracking; slow strain rate testing (SSRT); numerical modeling; stress-and-strain assisted diffusion of hydrogen; hydrostatic stress; plastic strain; hydrogen concentration. VII International Conference ―In -service Damage of Materials: Diagnostics and Prediction ‖ (DMDP 2023) Crack tip hydrogen diffusion assisted by stress and strain fields and its role in hydrogen assisted cracking Jesús Toribio * Fracture & Structural Integrity Research Group (FSIRG), University of Salamanca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain Abstract Crack tip hydrogen diffusion assisted by stress and strain fields is analysed in this paper, together with its role and implications in hydrogen assisted cracking (HAC). To this end, and firstly , a wide experimental programme was taken into account, consisting of slow strain rate tests (SSRT) on high-strength pearlitic steel rods under cathodic electrochemical conditions promoting HAC, considering the maximum stress intensity factor (SIF K max ) during fatigue pre-cracking as the relevant test variable, so as to consider the cyclic pre-loading history as the key factor in the further evolution of HAC. In addition, and secondly , a numerical analysis was performed of the effect of cyclic pre-loading regime on the posterior HAC behaviour of high-strength steel, considering both mechanical aspects (mechanical modelling: evolution of near-tip stress-strain fields) and chemical issues (hydrogen diffusion modelling: evolution on near-tip hydrogen concentration distributions). Results show clearly that hydrogen accumulation in prospective fracture sites depends on residual stress distributions produced by cyclic pre-loading. VII International Conference ―In -service Damage of Materials: Diagnostics and Prediction ‖ (DMDP 2023) Crack tip hydrogen diffusion assisted by stress and strain fields and its role in hydrogen assisted cracking Jesús Toribio * Fracture & Structural Integrity Research Group (FSIRG), University of Salamanca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain

* Corresponding author. Tel.: +34-677566723; fax: +34-980545002. E-mail address: toribio@usal.es * Corresponding author. Tel.: +34-677566723; fax: +34-980545002. E-mail address: toribio@usal.es

2452-3216 © 2024 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 DMDP 2023 Organizers 2452-3216 © 2024 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 DMDP 2023 Organizers

2452-3216 © 2024 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 DMDP 2023 Organizers 10.1016/j.prostr.2024.04.021