Fatigue crack growth in thin steel sheets

Surface fatigue crack growth is considered for thin steel sheets composed of two steels widely used in cryogenic engineering: 12Kh18N10T and 07Kh13N4AG20. Specimens with thicknesses of 4, 8, and 12 mm have been tested at 293 and 77 K (in liquid nitrogen). There is a boundary between the zones affected by the rear and front edges of the specimen in the plane of semielliptical crack growth, which affects the stress and strain patterns near the crack front. The boundary between the zones is approximated by a second-order curve. The thickness and the temperature affect the slope of the curve. The kinetic features are seen at points in the crack front at such boundaries.Translated from Problemy Prochnosti, No. 2, pp. 27–34, February, 1992.