Hardening effect of electron beam surface remelting on W6 steel

High-speed steel is a kind of special tool steel with high hardness and wear resistance. The microhardness loss of high-speed steel that is subjected to spheroidizing annealing is large, which significantly affects its application. In order to increase the microhardness of spheroidal annealing W6Mo5Cr4V2 high-speed steel surface, and to ensure its good internal toughness, the electron beam surface remelting is used to harden the surface. The remelting surface is flat and smooth with small craters. Cellular dendrites are observed in the remelting layer, which is mainly composed of martensite, residual austenite, M₂C eutectic carbide, and fine rod-shaped MC carbide, the formation process and types of intercrystalline carbides are analyzed. After electron beam surface remelting, the microhardness of the W6Mo5Cr4V2 high-speed steel surface is increased from 283 HV to more than 800 HV, indicating the prominent recovery effect of microhardness.