The Stability of Laser Hardening Structures to Softening During Heating

Abstract

Structural and phase changes occurring in laser-hardened steels after tempering at different temperatures are considered. It is shown that the optimization of laser processing and subsequent tempering allows to increase the heat resistance of steels 50-120°C by maintaining a high density of defects in the crystal structure and appearance of the uniform allocation of dispersed carbide particles. It is established that for the laser-irradiated metal, from the energy point of view, it is not the formation of ε-carbide during tempering, but the deposition of carbon atoms and alloying elements on structural imperfections with further formation of carbides according to the scheme: carbon in solid solution → carbon associated with defects → carbide on defects of the crystal structure.