Effects of Grain Size on Crack Tip Mechanical Fields of Intergranular Cracking

Abstract

Intergranular stress corrosion cracking is one of important failure form of structural materials in nuclear power plants, and the initiation and development of crack at grain boundary are affected by the grain size of materials. The macroscopic model and mesoscopic model of crack propagation was established by using finite element method, and the effects of grain size on fracture parameters such as Mises stress, the maximum principal stress and equivalent plastic strain nearby crack tip were studied. The results indicate that the distribution of Mises stress and equivalent plastic strain are discontinuity at grain boundary, and the maximum principal stress locates at grain boundary. The Mises stress, maximum principal stress and equivalent plastic strain nearby crack tip increase with the increasing of grain size.