Structural and phase states in austenitic steel subjected to high-cycle fatigue

Abstract

The destruction surface and defect substructure of the Fe-0.1C-1.71Mn-0.92Ti-18.2Cr-10.4Ni-0.71Si steel subjected to high-cycle fatigue tests is investigated by the methods of scanning and transmission electron microscopy. It is demonstrated that the fatigue tests, irrespective of the loading scheme (continuous or under conditions of intermediate stimulation by pulse current), result in the formation of a structural gradient in the material manifested through regular changes of the relief parameters of the destruction surface and defect substructure with increasing distance from the loading surface (face or back specimen side). It is revealed that scalar and excess dislocation density, volume fraction of grains that comprise deformation microtwins, and degree of dislocation substructure organization maximize near the free specimen surface.