二相ステンレス鋼の水素ぜい化破面の3次元破面解析

抄録

Fracturre surface apppears to be a three dimensional image when stereo-pair photographs are examined in a stereoscope. However since such image is not quantitative it is necessary to build up accurate three dimensional topography associated with fracture surface in order to increase understanding of fracture process. In this study, it became possible to obtain 3-dimensional fracture surface topography from stereo-pair of SEM photographs. Position search algorithm in a stereo-pair of SEM photographs used was SSDA and MCC methods. After searching position it was calculated fracture surface height by using geometric equation. And then, we applied software to hydrogen embrittlement fracture surface of SUS329J1 duplex stainless steel for quantitative analysis. As a result of that, 3-dimensional image was well corresponded to fracture surface associated. Furthermore we also investigated influence of microstructure (austenite, ferrite, sigma phase) on hydrogen embrittlement behavior by applying both 3-dimensional analysis and microstructure observation. As a result of that it found sigma/austenite phase boundaries and sigma/ferrite phase boundaries are preferential fracture site, while ferrite quasi-cleavage fracture in as-received material was dominant.