Comparison of the mechanical properties and wear resistance between two oil-hardening tool steels

The mechanical properties and wear rates of JIS SKS3 and BS BO1 oil-hardening tool steels after quenching from 790-940 degrees C and tempering at 2000 for two hours have been investigated. At the same quenching temperature, the impact toughness and bending fracture stress of BS BO1 tool steel were superior to that of JIS SKS3 tool steel. However, besides quenching from 880 degrees C, the tempered hardness of two oil-hardening tool steels were almost the same. The wear rate of BS BO1 tool steel was a little more faster than that of JIS SKS3 tool steel. Moreover, because of grain growth inhibition by fine vanadium carbides, the prior austenite grain size of BS BO1 tool steel was smaller than that of JIS SKS3 tool steel. The fracture surfaces of both tool steels were similar with ductile dimple fracture occurred at low quenching temperature and brittle intergranular fracture occurred at high quenching temperature. The differences of mechanical properties and wear rates between two oil-hardening tool steels were explained by their prior austenite grain sizes, microstructures, and amounts of retained austenite.