229 分子動力学法を用いたα鉄中の刃状転位近傍の水素拡散挙動解析(OS8-1 水素環境が金属強度特性に及ぼす影響,OS8 水素環境が金属強度特性に及ぼす影響)

抄録

Hydrogen embrittlemen mechanism is still remained issue to be clarified. Due to the recent studies, the interaction between dislocations and hydrogen is considered to plays an important role in hydrogen embrittlement. Therefore local hydrogen distribution or concentration around defects (e.g. dislocation) should be clarified. However the experimental investigations of the local hydrogen distribution have many difficulties due to the hydrogen character. In this study, the hydrogen diffusion behavior around an edge dislocation in pure iron is investigated based on molecular statics and molecular dynamics simulations. For an edge dislocation on the (112) slip plane, the potential energy distribution does not agree with the elastic theory near the dislocation core. Moreover, it is confirmed that the dislocation traps the hydrogen at the dislocation core and the exact slip plane by MD analysis. Therefore, on contrast with the elastic theory, the possibility of high hydrogen concentration along the slip plane near the dislocation core is proposed.