One-Way Coupled Crystal Plasticity-Hydrogen Diffusion Simulation on Artificial Microstructure

Many attempts were made in the past to investigate numerically the metal-hydrogen interactions at macro-scale but the actual microstructure was generally not introduced into the analyses. The objective of this work is to simulate, on an artificial polycrystal, the effect of the microstructure-induced stress-strain field heterogeneity on the internal hydrogen evolution. Finite element method is used to take into account explicitly the grain morphologies and their crystalline orientations into the description of the mechanical deformation. A one-way coupled crystal plasticity-transient hydrogen diffusion analysis is developed and applied to solve the boundary value problem. The analysis of the computed hydrogen content field shows that a segregation of hydrogen is observed mainly at the grain boundaries. It is also shown that grain size has a significant effect not only on the amount of hydrogen segregated at the grain boundaries but also on the relative size of concentration gradients.