フェライト系ステンレス鋼の腐食疲労過程におけるピット生成機構について

抄録

The present authors have been investigated on the corrosion fatigue crack initiation process of a ferritic stainless steel. Consequently, it was indicated that corrosion pit formulation is important for the corrosion fatigue crack initiation of this material. The factor which governs the corrosion pit nucleation process, however, has not yet been clarified. Therefore, in this paper, the mechanisms of pit formulation in the corrosion fatigue crack initiation process were investigated from the microstructural and crystallographical points of view. As a result, it was made clear that, few corrosion pit generation was recognized in the grains which have preferable crystal orientation for operating multiple slip systems. Therefore, it is understood that the two-dimensional opening of the surface passive film, which is caused by multiple slip deformations, is necessary for corrosion pit generation.