TY - JOUR

T1 - The effect of nitrogen alloying on hydrogen-assisted plastic deformation and fracture in FeMnNiCoCr high-entropy alloys

AU - Astafurova, E. G.

AU - Panchenko, M. Yu

AU - Reunova, K. A.

AU - Mikhno, A. S.

AU - Moskvina, V. A.

AU - Melnikov, E. V.

AU - Astafurov, S. V.

AU - Maier, H. J.

N1 - Funding Information: This study was supported by the Russian Science Foundation (project No. 20-19-00261) (E.G. Astafurova: Conceptualization, Supervision, Writing - original draft; M.Yu. Panchenko, K.A. Reunova, A.S. Mikhno, V.A. Moskvina, E.V. Melnikov, S.V. Astafurov: Methodology, Investigation, Visualization, Data curation, Formal analysis, Writing - review & editing). The studies were conducted using the equipment of the Institute of Strength Physics and Materials Science (NANOTECH center). H.J. Maier acknowledges financial support by the German Research Foundation (project number 388671975) (Review & editing of the manuscript).

PY - 2021/3/15

Y1 - 2021/3/15

N2 - In the present study, the effect of nitrogen alloying on hydrogen embrittlement in FeMnNiCoCr high-entropy alloys was investigated. In tension, hydrogen-free nitrogen-alloyed FeMnNiCoCrN alloy (0.37 wt.% N) demonstrated higher strength, strain hardening, and elongation-to-failure than the interstitial-free FeMnNiCoCr Cantor alloy. Despite the different tensile properties, both alloys fractured via a ductile dimple micromechanism. After hydrogen charging, the nitrogen-alloyed material demonstrated lower strain hardening and higher sensitivity to hydrogen-assisted embrittlement than the interstitial-free alloy. Both alloys featured a stable austenitic structure and similar grain size, yet, the nitrogen-alloyed FeMnNiCoCr alloy was more susceptible to hydrogen embrittlement. Although, the overall degradation effects appear similar, there are pronounced differences in mechanical behavior and hydrogen transport upon hydrogen charging when the high-entropy alloys are compared to conventional austenitic stainless steels, and the experiments reveales that nitrogen alloying enhances hydrogen diffusivity in the Cantor alloy.

AB - In the present study, the effect of nitrogen alloying on hydrogen embrittlement in FeMnNiCoCr high-entropy alloys was investigated. In tension, hydrogen-free nitrogen-alloyed FeMnNiCoCrN alloy (0.37 wt.% N) demonstrated higher strength, strain hardening, and elongation-to-failure than the interstitial-free FeMnNiCoCr Cantor alloy. Despite the different tensile properties, both alloys fractured via a ductile dimple micromechanism. After hydrogen charging, the nitrogen-alloyed material demonstrated lower strain hardening and higher sensitivity to hydrogen-assisted embrittlement than the interstitial-free alloy. Both alloys featured a stable austenitic structure and similar grain size, yet, the nitrogen-alloyed FeMnNiCoCr alloy was more susceptible to hydrogen embrittlement. Although, the overall degradation effects appear similar, there are pronounced differences in mechanical behavior and hydrogen transport upon hydrogen charging when the high-entropy alloys are compared to conventional austenitic stainless steels, and the experiments reveales that nitrogen alloying enhances hydrogen diffusivity in the Cantor alloy.

KW - Austenite

KW - Fracture

KW - High entropy alloy

KW - Hydrogen embrittlement

KW - Interstitials

UR - http://www.scopus.com/inward/record.url?scp=85096828242&partnerID=8YFLogxK

U2 - 10.1016/j.scriptamat.2020.113642

DO - 10.1016/j.scriptamat.2020.113642

M3 - Article

AN - SCOPUS:85096828242

VL - 194

JO - Scripta materialia

JF - Scripta materialia

SN - 1359-6462

M1 - 113642

ER -