Insights into hydrogen-induced vacancy stability and creep in chemically complex alloys
Abstract
Hydrogen (H) content modifies the creep response of Fe-based alloys by altering thermodynamics of point-defects; here we identify the electronic-structure mechanism underlying this effect. Using spin-polarized first-principles calculations combined with a cluster dynamics formulation, we establish a general framework linking H-assisted vacancy stabilization to diffusion-mediated creep in BCC Fe, FCC Fe, and chemically complex FCC Fe-Cr-Ni alloys. H-vacancy binding analysis shows that H-stabilized vacancies form at low hydrogen content in BCC Fe but require much higher chemical potentials in FCC Fe and Fe-Cr-Ni alloys due to broader d-bands, electronic screening, and chemical disorder. Consequently, plastic deformation mediated by diffusive processes is expected to be far more strongly impacted in BCC Fe than in FCC alloys. These electronic-controlled trends determine steady-state vacancy populations and provide a symmetry-resolved microscopic basis for H-assisted creep in ferritic and austenitic steels.
Keywords
Cite
@article{arxiv.2603.03707,
title = {Insights into hydrogen-induced vacancy stability and creep in chemically complex alloys},
author = {Prashant Singh and Yash Pachaury and Aaron Anthony Kohnert and Laurent Capolungo and Duane D. Johnson},
journal= {arXiv preprint arXiv:2603.03707},
year = {2026}
}
Comments
12 pages, 5 figures