高張力鋼における腐食疲労き裂の形態
1990 年 56 巻 522 号 p. 244-250
詳細
1990 年 56 巻 522 号 p. 244-250
Three-dimensional shape of a corrosion fatigue crack is investigated for a high-tensile strength steel, HT60, under plane bending in tap water. The crack accompanies a corrosion pit which is nearly a semi-sphere and is situated at the center of the crack on a specimen surface. The shape of the crack front is not a semi-ellipse but a circular arc. The ratio of the crack depth to crack length on the specimen surface is 0.286 (that is, a central angle subtending the arc is 120°). Crack opening due to dissolution of the crack surface is observed in all regions, except that near the crack front. The amount of opening and the area of dissolution depend on the applied stress amplitude, whereas the size of the corrosion pit is independent of it.
