PSI - Issue 31

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 31 (2021) 8–14

© 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 2020 Organizers. © 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 2020 Organizers. Abstract For a more acc rate predi tion f th service life f slewing bearings under oscillating od mecha ical customized fatigue test st ategies and suitable calculation methods have to be d veloped. In this study large- iameter slewing b arings of onshore wind turbi es made from i uction harden d nd tempered eel 42CrM 4 are investiga ed. Test samples were cut directly out of the bearing ring (core condition). The orientation of the test cross-section was chos to correspon ing with the presumed most critical orientation of non-met llic inclusions. After sampling three heat treatments wer carried out to mimic the diff rent heat treatment conditions of the be ring (raceway, transition region, core). Results o static tests (fr cture toughness, tensile strength) and cy lic tes ing (cr ck propagation, S-N-curve) w re obtain d for the three differ nt heat-treated sample batches. The results where correlat d to hardness, cleanliness and local resi u l stresses to d velop a deep understanding of crack initi tion and crack propagation mechanisms and m king a first step towards a more accurate prediction of fatigue life. In order to be able to transfer the analytic results to the real parts, a simulation model will be developed later on. © 2021 The Authors. Published by ELSEVIER B.V. This is an ope access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2020 Organizers. 4th International Conference on Structural Integrity and Durability, ICSID 2020 Influence of local differences in microstructure and hardness on the fatigue behaviour of a slewing bearing steel Vera Friederici a * , Jens Schumacher a , Brigitte . Clausen b a Leibniz Institute for Materials Engineering – IWT, Badgasteiner Str. 3, 28359 Bremen, Germany b University of Bremen, Faculty of Production Engineering, Research Group Materials Engineering Metals, Badgasteiner Str. 1, 28359 Bremen, Germany Abstract For a more accurate prediction of the service life of slewing bearings under oscillating mode mechanical customized fatigue test strategies and suitable calculation methods have to be developed. In this study large-diameter slewing bearings of onshore wind turbines made from induction hardened and tempered steel 42CrMo4 are investigated. Test samples were cut directly out of the bearing ring (core condition). The orientation of the test cross-section was chosen to corresponding with the presumed most critical orientation of non-metallic inclusions. After sampling three heat treatments were carried out to mimic the different heat treatment conditions of the bearing (raceway, transition region, core). Results of static tests (fracture toughness, tensile strength) and cyclic testing (crack propagation, S-N-curve) were obtained for the three different heat-treated sample batches. The results where correlated to hardness, cleanliness and local residual stresses to develop a deep understanding of crack initiation and crack propagation mechanisms and making a first step towards a more accurate prediction of fatigue life. In order to be able to transfer the analytic results to the real parts, a simulation model will be developed later on. 4th International Conference on Structural Integrity and Durability, ICSID 2020 Influence of local differences in microstructure and hardness on the fatigue behaviour of a slewing bearing steel Vera Friederici a * , Jens Schumacher a , Brigitte . Clausen b a Leibniz Institute for Mater als E ine ring – IWT, Badgasteiner Str. 3, 28359 Bremen, Germa y b University of Bremen, Faculty of Production Engineering, Research Group Materials Engineering Metals, Badgasteiner Str. 1, 28359 Bremen, Germany

Keywords: crack propagation; crack initiation; heat treatment; prediction of fatigue life Keywords: crack propagation; crack initiation; heat treatment; prediction of fatigue life

* Corresponding author. Tel.: +49-421-218-51427; fax: +49-421-218-51333. E-mail address: friederici@iwt-bremen.de * Correspon ing author. Tel.: +49-421-218-51427; fax: +49-421-218-51333. E-mail address: friederici@iwt-bremen.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 2020 Organizers. 2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an ope acces article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2020 Organizers.

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 2020 Organizers. 10.1016/j.prostr.2021.03.003