Phase-Field Modeling of Hydrogen Diffusion and Trapping in Steels

Hydrogen embrittlement of steels is directly linked to hydrogen diffusion and trapping in the microstructure,which can hardly be precisely measured by modern experimental techniques.A phase-field model,in which a chemical potential well of hydrogen in the grain boundaries is introduced,is proposed to simulate hydrogen diffusion and trapping in the polycrystal-line iron.It was interestingly found that grain boundaries,as connected trap sites,have a complex influence on the effective diffusivity of hydrogen,which are strongly linked to grain boundary diffusivity and binding energy.