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) 718–723

2nd Mediterranean Conference on Fracture and Structural Integrity A modified Paris Law approach to fatigue crack propagation in cold drawn pearlitic steel 2nd Mediterranean Conference on Fracture and Structural Integrity A modified Paris Law approach to fatigue crack propagation in cold drawn pearlitic steel

Jesús Toribio*, Beatriz González, Juan-Carlos Matos Fracture & Structural Integrity Research Group (FSIRG), University of Salamanca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain Jesús Toribio*, Beatriz González, Juan-Carlos Matos Fracture & Structural Integrity Research Group (FSIRG), University of al manca (USAL) E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora, Spain

© 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: pearlitic steel; cold drawing; pearlite microstructural orientation; Toribio-González-Matos (TGM) model; conventional Paris Law; modified Paris Law, zig-zag fatigue crack path; tortuous fatigue crack path; microstructurally-induced fatigue crack path. Abstract This scientifi ar icle offers an innovative ap r ach to fatigue crack growth in progressively cold d awn pearlitic steels that exh t a microstructurally-induced tortuous pr p gation path ( zig-zag fatigue crack path). The proposed novel approac , Toribio-González-Matos (TGM) model, c n ists of a modified Paris Law including the real fatigu crack growth length (i.e., the locally multiaxial, microstructurally tortuous, f tigue crack growth distance) instead f the app ren fatigue crack growth length (i.e., the globally u iaxi l, f tigue cra k propagation dista ce, projecte in the direction of global f tigue propagation in mode I). Whereas the conventional Paris Law considers t apparent projected distance (straight line), the approach in roduced here (i.e., the TGM model) propos s the consideration of the rea , non-projected, tortuous, microstructurally-induced fatigue crack growth l ngth with zig-za shape (longer that the conventionally projected in global mode I). It is seen that the fatigu crack propagation real distance (lo g r) when compared to th fatigue crack propagati n projected distance (sh rter) is the reason for the better fatigue performance of heavily cold drawn pearlitic steels in rel tion to the performa ce of the original hot rolled m terial before cold drawing, due to the increase of microscopically-induced crack deflection angle in the heavily cold drawn material. © 2022 The Authors. Published by ELSEVIER B.V. This is an ope access article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2 Guest Editors Keywor s: pearlitic steel; cold drawing; earli e microstruct ral orientation; T ribio-González-Matos (TGM) model; conventional Paris Law; modified Paris Law, zig-zag fatigue crack path; tortuous fatigue crack path; microstructurally-induced fatigue crack path. Abstract This scientific article offers an innovative approach to fatigue crack growth in progressively cold drawn pearlitic steels that exhibit a microstructurally-induced tortuous propagation path ( zig-zag fatigue crack path). The proposed novel approach, Toribio-González-Matos (TGM) model, consists of a modified Paris Law including the real fatigue crack growth length (i.e., the locally multiaxial, microstructurally tortuous, fatigue crack growth distance) instead of the apparent fatigue crack growth length (i.e., the globally uniaxial, fatigue crack propagation distance, projected in the direction of global fatigue propagation in mode I). Whereas the conventional Paris Law considers the apparent projected distance (straight line), the approach introduced here (i.e., the TGM model) proposes the consideration of the real, non-projected, tortuous, microstructurally-induced fatigue crack growth length with zig-zag shape (longer that the conventionally projected in global mode I). It is seen that the fatigue crack propagation real distance (longer) when compared to the fatigue crack propagation projected distance (shorter) is the reason for the better fatigue performance of heavily cold drawn pearlitic steels in relation to the performance of the original hot rolled material before cold drawing, due to the increase of microscopically-induced crack deflection angle in the heavily cold drawn material.

* 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.2022.05.082