PSI - Issue 42

Available online at www.sciencedirect.com Available online at www.sciencedirect.com

ScienceDirect ScienceDirect

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

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

ScienceDirect

Procedia Structural Integrity 42 (2022) 471–479

23 European Conference on Fracture - ECF23 23 European Conference on Fracture - ECF23

© 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 scientific committee of the 23 European Conference on Fracture – ECF23 Hydrogen embrittlement (HE) is a idely occurring problem, also in the automotive industry. Therefore, this study compares the resistance to HE of tw types of bearing steels: an industrial 100Cr6 steel and an innovative Fe-8Al 1.1C steel. The innovative character of the Fe-8Al-1.1C steel is found in the fact that a high weight fraction of Al is added to a simplified Fe-1.1C alloy which results in a low-cost martensitic steel with a similar hardness but a lower density, compared to the industrial 100Cr6 steel. The density reduction offers the opportu ity to reduce the vehicle weight and as such to reduce the CO 2 emission of fuel-based cars or extend the driving range of electrical vehicles. Both alloys are subjected to a similar heat treatment resulting in a martensitic matrix with specially induced carbides. (In-situ) H bending tests and subseque t post-mortem fracture surface analysis are performed to investigate the mechanical degradation of both steels in a H rich environment. For the industrial steel grade, the large Cr-based carbides act as fracture initiation sites for H-assisted cracks. In contrast, the fracture behavior of the Fe-8Al-1.1C material is similar in air and in an H containing environment, indicating that the Fe-8Al-1.1C steel has a better resistance to HE. Although these results are very promising, further optimization of the innovative alloy is needed to improve the mechanical behavior in the absence of H since the presence of microcracks cause premature failure when tested in air. Comparison between the hydrogen embrittlement behavior of an industrial and a lightweight bearing steel Margot Pinson a , Ksenija Nikolic b , Hauke Springer c, d , Tom Depover a *, Kim Verbeken a * a Department of Materials, Textiles and Chemical Engineering, Ghent University, Technologiepark 46, 9052 Gent, Belgium b Department of Electromechanical, Systems and Metal Engineering, Ghent University, Technologiepark 46, 9052 Ghent, Belgium c Institut für Bildsame Formgebung, RWTH Aachen University, Intzestrasse 10, 52056 Aachen, Germany d Department of Microstructure Physics and Alloys Design, Max-Planck-Institut für Eisenforschung (GmbH), Max-Planck-Straße 1D, 40237 Düsseldorf, Germany Hydrogen embrittlement (HE) is a widely occurring problem, also in the automotive industry. Therefore, this study compares the resistance to HE of two types of bearing steels: an industrial 100Cr6 steel and an innovative Fe-8Al 1.1C steel. The innovative character of the Fe-8Al-1.1C steel is found in the fact that a high weight fraction of Al is added to a simplified Fe-1.1C alloy which results in a low-cost martensitic steel with a similar hardness but a lower density, compared to the industrial 100Cr6 steel. The density reduction offers the opportunity to reduce the vehicle weight and as such to reduce the CO 2 emission of fuel-based cars or extend the driving range of electrical vehicles. Both alloys are subjected to a similar heat treatment resulting in a martensitic matrix with specially induced carbides. (In-situ) H bending tests and subsequent post-mortem fracture surface analysis are performed to investigate the mechanical degradation of both steels in a H rich environment. For the industrial steel grade, the large Cr-based carbides act as fracture initiation sites for H-assisted cracks. In contrast, the fracture behavior of the Fe-8Al-1.1C material is similar in air and in an H containing environment, indicating that the Fe-8Al-1.1C steel has a better resistance to HE. Although these results are very promising, further optimization of the innovative alloy is needed to improve the mechanical behavior in the absence of H since the presence of microcracks cause premature failure when tested in air. Comparison between the hydrogen embrittlement behavior of an industrial and a lightweight bearing steel Margot Pinson a , Ksenija Nikolic b , Hauke Springer c, d , Tom Depover a *, Kim Verbeken a * a Department of Materials, Textiles and Chemical Engineering, Ghent University, Technol giepark 46, 9052 Gent, Belgium b Department of Electromechanical, Systems and Metal Engin ering, Ghent University, Technologiep rk 46, 9052 Ghent, Belgium c Institut für Bildsame Formgebung, RWTH Aachen University, Intze trasse 10, 52056 Aachen, Germany d Department of Microstructure Physics and Alloys Design, Max-Planck-Institut für Eisenforschung (GmbH), Max-Planck-Straße 1D, 40237 Düsseldorf, Germany Abstract Abstract

* Corresponding author. Tel.: +32 93 31 04 53. E-mail address: tom.depover@ugent.be, kim.verbeken@ugent.be * Correspon ing author. Tel.: +32 93 31 04 53. E-mail address: tom.depover@ugent.be, kim.verbeken@ugent.be

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23

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 scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.060