ACOUSTIC EMISSION STUDIES OF DEFORMATION AND FRACTURE OF STEELS.

Acoustic emission is increasingly used as a research tool for studying the microstructural mechanisms associated with plastic deformation as well as the fracture process in metallic materials. In this study, correlations between acoustic emission and microstructure in plastically deformed materials are presented. Kaiser effect is examined in pure iron to determine the micromechanisms responsible for its occurrence. Also, acoustic emission during fracture testing is correlated with general yielding at the crack tip and the formation of a plastic zone. In low-cycle fatigue, relationships between acoustic emission and microstructure are developed for steels with varying microstructures obtained by different heat treatment.