PSI - Issue 68

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 68 (2025) 493–499

European Conference on Fracture 2024 Fatigue limit of advanced bainitic steels: notch effect Lucia Morales-Rivas a,b *, Eberhard Kerscher b a Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, Madrid E-28040, Spain b Materials Testing (AWP), Rheinland-Pfälzische Technische Universitat Kaiserslautern - Landau (RPTU), Gottlieb-Daimler-Straße, Kaiserslautern 67663, Germany Abstract The explanation of fatigue mechanisms in the presence of notches is far from being resolved, particularly when materials with a complex microstructure are the subject of the research. In this work, alternative analyses of experimental results from notch fatigue of advanced bainitic steels are revisited. © 2025 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 ECF24 organizers Keywords: Advanced steels; nanostructured bainite; nanobainitic steels; fatigue crack nucleation; fatigue crack propagation; notch fatigue © 2025 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 ECF24 organizers

1. Introduction: Neuber-based approaches on notch fatigue 1.1. Fatigue limit of notched specimens

Disclosing the extent at which the presence of notches influences the mechanical fatigue limit in materials is a field of research that has produced abundant literature during decades. Notch fatigue impels not only the mechanical design of engineering components but also the design of alloys and microstructures. The study of notch fatigue can be approached by making use of Kitagawa-Takahashi-like diagrams -Kitagawa and Takahashi (1976)-, in an analogous way as for smooth specimens where the presence of defects or cracks is considered. Such a scenario (smooth case) corresponds to the schematic diagram in Fig. 1.a, representing the threshold of the gross stress (net-section stress)

* Corresponding author. Tel.:+31-91-3333289. E-mail address: l.morales-rivas@cenim.csic.es

2452-3216 © 2025 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 ECF24 organizers

2452-3216 © 2025 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 ECF24 organizers 10.1016/j.prostr.2025.06.087