PSI - Issue 54

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 54 (2024) 250–255

© 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 the scientific committee of the ICSI 2023 organizers Abstract A virtually limitless amount of metals can be produced following the high entropy concept, of which at least some of them have shown to exhibit extraordinary properties such as high strength or toughness. Several compositions also seem to possess excellent resistance to hydrogen embrittlement. In this work, a near-equiatomic CoCrFeMnNi is investigated in interaction with hydrogen. The material is characterized by a higher hydrogen solubility and diffusivity as compared to an austenitic stainless steel due to the complex chemistry able to accommodate more hydrogen as well as providing fast hydrogen diffusion paths. The material is significantly embrittled after electrochemical hydrogen charging. A transitional fracture surface is observed through the thickness which can be linked to the hydrogen concentration gradient. High hydrogen concentration leads to intergranular fracture, while more moderate hydrogen concentrations lead to quasi-cleavage type of fracture. © 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 the scientific committee of the ICSI 2023 organizers Keywords: High entropy alloy, hydrogen, ductility loss, transitional fracture 1. Introduction High entropy alloys (HEAs) are multi-element materials where the constituting elements are present in large quantities, i.e. between 5 and 35 at% (Miracle, Senkov, 2017). This specific alloy design results in diverse but single solid solution phase microstructures, making them particularly intriguing for studying their response to different environmental factors, including hydrogen exposure. Especially faced centered cubic (FCC) type HEAs are promising hydrogen embrittlement resistant materials due to their intrinsic low hydrogen diffusivity combined with high hydrogen solubility. A recent review indicated that Cantor alloy, an equiatomic HEA of cobalt, chromium, iron, manganese and nickel, only showed a limited reduction in mechanical performance in the presence of hydrogen International Conference on Structural Integrity 2023 (ICSI 2023) Hydrogen interaction with FCC CoCrFeMnNi high entropy alloy Lisa Claeys a , Mohammadhossein Barati Rizi a , Kim Verbeken a* , Tom Depover a * a Ghent University, Department of Materials, Textiles and Chemical Engineering, Research group Sustainable Materials Science, Technologiepark 46, 9052 Zwijnaarde, Belgium

* Corresponding author. Tel.: +32 9 331 04 33 E-mail address: Kim.Verbeken@UGent.be; Tom.Depover@UGent.be

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 the scientific committee of the ICSI 2023 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 the scientific committee of the ICSI 2023 organizers 10.1016/j.prostr.2024.01.080