Relation between fatigue damage and half-value breadth of X-ray diffraction lines in fatigue processes of carbon steels.

Abstract

For annealed and prestrained carbon steels, the relation between the change in fatigue damage of the specimen surface and the value of half breadth of X-ray diffraction lines in the fatigue processes has been investigated. The place observed by a microscope is included in the area irradiated by X-ray. For annealed carbon steels the half-value breadth increases remarkably in the early period of stress cycles, while for prestrained steels, it decreases remarkably. The period of abrupt change in the half-value breadth corresponds to the period of abrupt change in the density of slip lines in both steels. In the process of the initiation and propagation of microcracks, the change in the half-value breadth is not marked.