3515 くり返し応力条件下における動転位群と水素との相互作用効果による劈開破壊機構(S20-3 水素ガス雰囲気での疲労特性,S20 材料強度特性に及ぼす水素の影響)

抄録

Transgranular facet like brittle fracture for ductile materials under corrosive conditions is caused by the typical pile-up of dislocations. It was found that the mechanical interaction between dislocations and hydrogen induces the typical pile-up of dislocations. Therefore, the analysis of interaction between dislocations and hydrogen under cyclic loading condition was conducted to investigate the distribution behavior of dislocations under corrosion fatigue conditions. In this analysis, the effect of applied stress wave forms on distribution and pile-up behavior of dislocations was investigated. Furthermore, concerning the concentration of dislocations at the site of hydrogen atom, dislocation pile-up intensity factor A was defined. The effect of stress wave form on ΔA was found to concern the feasibility of the occurrence of facet like fracture. Based on the concept of ΔA, the facet like fracture is found to be promoted under Fast-Slow stress wave form condition.