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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ScienceDirect

Procedia Structural Integrity 59 (2024) 90–97

© 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 Abstract A fracture mechanics approach to hydrogen-assisted micro-damage (HAMD) in pearlitic steel is presented. Fractographic analysis revealed micromechanical effects of hydrogen in the form of tearing topography surface (TTS). The progress of this micro-damage is modeled as a macroscopic crack that extends the original fatigue pre-crack and involves linear elastic fracture mechanics (LEFM) principles. In this case, the change from hydrogen-assisted micro-damage (TTS) to cleavage-like topography takes place when a critical stress intensity factor (SIF) in the hydrogen environment ( K H ) is reached, and this value depends on the amount of hydrogen which penetrated the vicinity of the actual crack tip (the fatigue pre-crack plus the TTS area). The present study analyzes the effect of the TTS zone aspect ratio on the critical SIF in hydrogen K H . © 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: pearlitic steel; eutectoid steel; hydrogen-assisted micro-damage (HAMD); tearing topography surface (TTS); TTS zone; TTS region; TTS crack; fracture mechanics approach. VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Crack tip hydrogen assisted microdamage in fully pearlitic steel: The Tearing Topography Surface (TTS) Jesús Toribio * Fracture & Structural Integrity Research Group (FSIRG), University of Salamanca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain Abstract A fracture mechanics approach to hydrogen-assisted micro-damage (HAMD) in pearlitic steel is presented. Fractographic analysis revealed micromechanical effects of hydrogen in the form of tearing topography surface (TTS). The progress of this micro-damage is modeled as a macroscopic crack that extends the original fatigue pre-crack and involves linear elastic fracture mechanics (LEFM) principles. In this case, the change from hydrogen-assisted micro-damage (TTS) to cleavage-like topography takes place when a critical stress intensity factor (SIF) in the hydrogen environment ( K H ) is reached, and this value depends on the amount of hydrogen which penetrated the vicinity of the actual crack tip (the fatigue pre-crack plus the TTS area). The present study analyzes the effect of the TTS zone aspect ratio on the critical SIF in hydrogen K H . © 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: pearlitic steel; eutectoid steel; hydrogen-assisted micro-damage (HAMD); tearing topography surface (TTS); TTS zone; TTS region; TTS crack; fracture mechanics approach. VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Crack tip hydrogen assisted microdamage in fully pearlitic steel: The Tearing Topography Surface (TTS) 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.2024.04.014