Laser strengthening of tool steels

摘要

This paper presents results of SEM, microhardness, residual stress (measured using Weissman-Philips method) and abrasion resistance examination of a surface layer of the tools steels remelted with a laser beam. Laser remelting of the tool steels provides strengthening an increase of the surface layer as a result of formation of highly refined, nonequilibrium products of the austenite transformation. There is obtained an increase of microhardness and abrasion resistance of the surface layer in relation to traditionally heat treated steels. The influence of the tempering temperature after a laser hardening on the distribution and the residual stresses values was also examined. The values of the stresses decrease with the distance from the surface treated. Tempering steels after a laser treatment led to decreased values of the residual stresses by about 30 to 50 MPa.