Modeling of Hydrogen Transport in Static and Rolling Contact

Hydrogen diffusion into steel is known to be one of the degradation material processes causing a reduction in material toughness (embrittlement) and fatigue strength, which enhances crack initiation and propagation under rolling contact loading conditions. The current work presents a finite element study of hydrogen diffusion into a metal substrate loaded by static and rolling contact. The main goal of the study is to investigate the stress effect on hydrogen transport. Initially a stress–diffusion problem for static Hertzian contact is solved and later for more complicated rolling contact conditions. Rolling contact is considered here by the moving Hertzian pressures existing around the bearing ring. Governing equations are given in dimensionless form, and a parametric study analyzing the influence of different dimensionless parameters on subsurface concentration of hydrogen is presented.