Theoretical clarification of facet like fracture in hydrogen embrittlement

Based on a two dimensional physical model of a mode I crack with a slip band, the analysis of mechanical interaction between hydrogen and dynamic dislocations with non-steady emission from a stressed source around a crack tip was conducted. To analyze the mechanical interaction between a crack and dynamic dislocations on a neighboring slip band, a crack is replaced by static discrete dislocations mechanically equivalent with the crack and a physical model of analyzing the mechanical interaction between static, dynamic dislocations and hydrogen was constructed. The occurrence conditions of the mechanisms of corrosive anodic chemical reaction. inter granular cracking due to hydrogen concentration and facet like fracture due to the intention between hydrogen and dynamic dislocations were clarified. These results were found to be in good agreement with previous results pased on a convenient one dimensional model. Furthermore, the competitive interaction between hydrogen and dynamic dislocations which causes the facet like fracture was found to occur under the limited velocity range of hydrogen and dynamic dislocations which is closely related to the corresponding range of yield stress.