Precipitation Behaviors of Carbides in High Speed Steel during ESR and Heat Treatment

Abstract

The microstructure and carbides evolution of high-speed steel after electroslag remelting and solution treatment were studied. The thermodynamic precipitation mechanism of carbides in solid phase was discussed and the characteristic parameters of carbides in different processes were also investigated. The results show that there were large lamellar and fibrous Mo2C and a small amount of VC in the ESR ingot. Mo2C are metastable carbides, which can be decomposed into VC and Fe2Mo4C during the solution treatment. The average diameter of the carbides is reduced to 1.28 μm and the space distance is reduced to 3.23 μm after forging and hot rolling, which means carbides are completely spheroidal and dispersed in matrix.