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) 728–735

© 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; cracked samples; kinematic fracture criterion; crack tip strain rate (CTSR); local strain rate at a crack tip; local strain rate in the vicinity of a crack tip; global strain rate; remote strain rate; applied displacement rate; crosshead speed; kinematic variables; environmentally assisted cracking. Abstract This paper offers a kinematic fracture criterion for hydrogen embrittlement (or hydrogen assisted cracking) of cracked samples of igh strength pearlitic steel tested at very different loading/straining rates under cathodic electrochemical condition promoting hyd ogen entry nd diffusion into the specimens. The local strain rate at the crack tip ( cra k tip strain rate CTSR) is shown to be the relev nt variable gov rning the hydrogen mbrittlement process. Calculation f the loc l strain rate is rried out on the basi of the elastic displacement distributio in the vicinity of a crack tip in onditions of plain strain. A local reference length is chosen next to the crack tip, at a distance estimated from th fr ctographic results of the tests that show a zone microscopically affected by hydroge . The other relevant variable in hyd ogen assisted cra king is t e depth of the maximum hydrostatic stress point, which is obtained by using approximate stress distributions in the vicinity of the crack tip in the elastic-plastic regime, or calculated as the asymptotic depth (for quasi-static tests) of the hydrogen affected area. © 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 mbrittlement; cracked samples; kinematic fracture criterio ; crack tip strain rate (CTSR); local train rate at a crack tip; local strain rate in the vicinity of a rack tip; global strain rate; remote strain rate; applied displacement rate; crosshead speed; kinematic variables; environmentally assisted cracking. 2nd Mediterranean Conference on Fracture and Structural Integrity Hydrogen embrittlement of pearlitic steel in the presence of cracks: A kinematic fracture criterion based on the crack 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 cracking) of cracked 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 crack tip ( crack tip strain rate CTSR) is shown to be the relevant variable governing the hydrogen embrittlement process. Calculation of the local strain rate is carried out on the basis of the elastic displacement distribution in the vicinity of a crack tip in conditions of plain strain. A local reference length is chosen next to the crack tip, at a distance estimated from the fractographic results of the tests that show a zone microscopically affected by hydrogen. The other relevant variable in hydrogen assisted cracking is the depth of the maximum hydrostatic stress point, which is obtained by using approximate stress distributions in the vicinity of the crack tip in the elastic-plastic regime, or calculated as the asymptotic depth (for quasi-static tests) of the hydrogen affected area. 2nd Mediterranean Conference on Fracture and Structural Integrity Hydrogen embrittlement of pearlitic steel in the presence of cracks: A kinematic fracture criterion based on the crack 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.2022.05.084