Crystal plasticity simulation on stress corrosion cracking considering oxygen diffusion along grain boundary

Aoyagi, Yoshiteru; Igarashi, Takahiro  ; Kaji, Yoshiyuki  

Stress corrosion cracking (SCC) is one of the critical concerns as degradation of structural components in light water reactors (LWRs) for long period. Many studies on intergranular SCC (IGSCC) have been conducted over several decades, however the mechanism of IGSCC initiation and propagation is not fully understood. In this study, in order to investigate the mechanism of IGSCC, we propose the multi-physics model with the combination of oxygen atom diffusion model and crystal plasticity model for IGSCC. Using this model, we conduct the simulation of crack propagation for polycrystalline metals. The conclusions obtained here are summarized as follows: (1) In the present model, it is possible to reproduce that IGSCC cracks propagate with branching by repeating growth and stop processes of micro cracks. (2) The behavior of oxygen along the grain boundary might be one of the important factors which determine the geometry of IGSCC propagation.