PSI - Issue 41

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Procedia Structural Integrity 00 (2022) 000–000 Available online at www.sciencedirect.com ScienceDirect Procedia Structural Integrity 00 (2022) 000–000

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Procedia Structural Integrity 41 (2022) 736–743

© 2022 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 the MedFract2Guest Editors. © 2022 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 the MedFract2 Guest Editors Keywords: hydrogen embrittlement; notched samples; kinematic fracture criterion; notch tip strain rate (NTSR); local strain rate at a notch tip; local strain rate in the vicinity of a notch tip; global strain rate; remote strain rate; applied displacement rate; crosshead speed; kinematic variables; environmentally assisted fracture. Abstract This paper offers a kinematic fracture criterion for hydrogen embrittlem nt (or hydrogen assisted fracture) of otched samples of igh strength pearlitic steel tested at very different loading/straining rates u der cathodi electrochemical condition promoting hyd ogen entry and diffusion into the specimens. The local strain rate at t e notch tip ( notch tip strain rate NTSR) is sh wn to be the elevant variable gov rning the hyd ogen embritt ement process. To this end, a fractur criterion is kin matically formulated over the hydrogen affected z ne: fractu e will take place when the equivalent str ss reaches a critical valu over a critic l zon , both being a function of the local strain r te at the notch tip ( r notch tip strain rat NTSR). Experimental results sh w that under certain conditions th results are universal and independe t of the pecimen geom try, wh ch supports the validity of the present approach and the relevance of the role of local strain rate in the close vicinity of the notch tip. © 2022 The Authors. Published by ELSEVIER B.V. This is an open acces article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2 Guest Editors Keywords: hydrogen embrittlement; notched samples; kinematic fracture crite io ; notch tip strain rate (NTSR); local train rate at a notch tip; local strain rate in the vicinity of a notch tip; global strain rate; remote strain rate; applied displacement rate; crosshead speed; kinematic variables; environmentally assisted fracture. 2nd Mediterranean Conference on Fracture and Structural Integrity Hydrogen embrittlement of pearlitic steel in the presence of notches: A kinematic fracture criterion based on the notch tip strain rate Jesús Toribio * Fracture & Structural Integrity Research Group (FSIRG), University of Salamanca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain Abstract This paper offers a kinematic fracture criterion for hydrogen embrittlement (or hydrogen assisted fracture) of notched samples of high strength pearlitic steel tested at very different loading/straining rates under cathodic electrochemical conditions promoting hydrogen entry and diffusion into the specimens. The local strain rate at the notch tip ( notch tip strain rate NTSR) is shown to be the relevant variable governing the hydrogen embrittlement process. To this end, a fracture criterion is kinematically formulated over the hydrogen affected zone: fracture will take place when the equivalent stress reaches a critical value over a critical zone, both being a function of the local strain rate at the notch tip (or notch tip strain rate NTSR). Experimental results show that under certain conditions the results are universal and independent of the specimen geometry, which supports the validity of the present approach and the relevance of the role of local strain rate in the close vicinity of the notch tip. 2nd Mediterranean Conference on Fracture and Structural Integrity Hydrogen embrittlement of pearlitic steel in the presence of notches: A kinematic fracture criterion based on the notch tip strain rate Jesús Toribio * Fracture & Structural Integrity Research Group (FSIRG), University of al manca (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 * Correspon ing author. Tel.: +34-677566723; fax: +34-980545002. E-mail address: toribio@usal.es

2452-3216 © 2022 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 the conference Guest Editors 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0)

Peer-review under responsibility of the conference Guest Editors

2452-3216 © 2022 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 the MedFract2Guest Editors. 10.1016/j.prostr.2022.05.085