OBSERVATION ON MICROSTRUCTURE OF LASER MELTED TRANSITION ZONE

The surface alloying specimen was made from the steel 45 substrate overcoating by oxygen-acetylene flame spraying Fe-Cr-Ni alloy powder and laser remelting.The chemical heterogeneity was clearly observed on the transition zone between the laser melted zone and heat-affected zone by means of EPMA,AES and SEM.This heterogeneity is rather serious during high temperature tempering,so the decarburization on the transition zone side and the recarburization on the melted zone side were found.