抄録
Electron backscattering diffraction (EBSD) method and atomic force microscopy (AFM) were utilized to investigate the active slip systems and fatigue crack initiation behavior in stainless steel, SUS316NG, under torsion. The analysis of active slip systems based on Schmid factor shows that most grains possess the slip plane with the largest Schmid factor value as their primary slip plane. Fatigue cracks were divided into 4 types: GB (Grain Boundary), TB (Twin Boundary), SB (Slip Band), TC (Transcrystalline). The results of crack density distribution in comparison with the earlier research in tensional fatigue tests show that under low loading level TC cracks dominate the initiation stage regardless of the loading mode. The profile at the cross section of SB crack was measured by AFM. The observed tilt angle of slip plane agrees very with its theoretic value.
