Hydrogen-reduced dislocation line tension in fcc nickel Available to Purchase

Dislocation Line tension G is a critical property inherent to continuum scale plasticity models of metal during hydrogen embrittlement (HE) process. In this study, we employ atomistic simulations combined with hybrid grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods to systematically investigate the effects of hydrogen on edge and screw dislocations in face-centered cubic (FCC) Ni. Hydrogen was found to preferentially segregate to tensile regions, resulting in a reduction of dislocation line tension. To capture the kinetics of curved dislocation motion, we proposed an effective Peierls stress formalism for bow-out configurations, allowing separation of intrinsic lattice resistance from hydrogen-induced effects. The results reveal a dual mechanism: at low hydrogen concentrations, line tension softening promote dislocation bow-out; at high concentrations, hydrogen drag dominates and suppresses dislocation mobility. This work provides fundamental insights into hydrogen–dislocation interactions and highlights the complex behavior of hydrogen embrittlement.