Effects of vanadium and carbon on microstructures and abrasive wear resistance of high speed steel

The effects of vanadium and carbon on microstructures and abrasive wear resistance of high speed steel were studied. The results show that the microstructures are characterized by VC, M7C3 and Mo2C in the martensite and austenite matrix. Typical morphologies of vanadium carbides are found to be spherical, lumpy, strip, and short rod. On the other hand, the vanadium carbides have three kinds of distributions, i.e. grain boundary, chrysanthemum-like, and homogeneous distributions. The abrasive wear resistance of high speed steel depends on the hardness and microstructures. When the hardness is lower than HRC58, the abrasive wear resistance of the high speed steel mainly depends on its hardness. But when the hardness is higher than HRC58, it mainly depends on the amount, morphology and distribution of VC in the matrix. Many spherical or lumpy VC carbides are obtained when vanadium and carbon content is up to 8.15–10.20 and 2.70–3.15%. The excellent abrasive wear resistance would be obtained if such VC carbides disperse uniformly in the hardened matrix of high speed steel after quenched at 1050 °C and tempered at 550 °C.