On origin of delta eutectoid carbide in M2 high-speed steel and its behaviour at high temperature

Abstract

Abstract Delta eutectoid can affect mechanical properties of high-speed steels. Nevertheless, the morphology and the origin of the carbide formed in delta eutectoid, as well as its microstructural changes under the effect of high temperatures, have not been completely investigated till now. To overcome it, the morphology and origin of the carbide in the delta eutectoid of M2 steel were thoroughly examined. The results showed that both M2C and M6C carbides could simultaneously form delta eutectoid. During annealing at 1200 °C, M2C decomposed into the mixture of M6C and V-rich carbides.