PSI - Issue 46

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 46 (2023) 94–98

© 2023 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 ICSID 2021 Organizers Abstract During cold forming processes of metals, such as forward extrusion, ductile pre-damage occurs in the microstructure which can strongly influence the mechanical properties of components, especially under operating conditions. The influence of typical forming process parameters on the bending fatigue behavior and the damage evolution is unknown so far. With the knowledge of forming-induced pre-damage influence on the fatigue performance, the design of components can be optimized in terms of higher safety and reliability, as well as lightweight construction. In this study, the influence of the deformation degree due to forming processes on the microstructure and the associated bending fatigue behavior of 16MnCrS5 steel is investigated. The aim is the development of a method for a sensitive and accurate non-destructive damage characterization. Therefore, direct current potential drop (DCPD) measurements are applied to determine damage state and evolution and to evaluate the interaction and separation of ductile pre-damage and fatigue damage mechanisms. The flat specimens of 16MnCrS5 steel in two deformation degrees are characterized by comparable microstructure and hardness, while pore size and number due to forming-induced pre-damage differ. Within electrical resistance measurements, the so-called delta mode is used to eliminate thermal effects. Consequently, increasing damage degree leads to increasing resistance. Furthermore, it is shown that the forming-induced pre-damage has no significant influence on the bending fatigue behavior in the high cycle fatigue (HCF) regime. © 2021 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 ICSID 2021 Organizers. Keywords: DCPD; 16MnCrS5; three-point bending fatigue; damage characterization 5th International Conference on Structural Integrity and Durability, ICSID 2021 Direct current potential drop characterization of forming-induced pre-damage influence on bending fatigue behavior of 16MnCrS5 L. Lücker a *, F. Walther a a TU Dortmund University, Chair of Materials Test Engineering (WPT), Baroper Str. 303, D-44227 Dortmund, Germany

* Corresponding author. Tel.: +49 231 755 90167. E-mail address: lukas.luecker@tu-dortmund.de

2452-3216 © 2021 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 ICSID 2021 Organizers.

2452-3216 © 2023 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 ICSID 2021 Organizers 10.1016/j.prostr.2023.06.016