Structure and Properties of a Deposited High-Entropy Molybdenum High-Speed Steel Layer Subjected to Multiple Heat Treatment
摘要
A 9-mm-thick layer of M10-based high-entropy high-speed steel is deposited onto 30KhGSA steel by plasma spraying in a nitrogen atmosphere. This layer is subjected to combined heat treatment, which consists of double high-temperature tempering followed by irradiation by an intense submillisecond-pulse electron beam (30 J/cm2, 50 μs, 0.3 s–1, 10 pulses). The treatment of the layer/substrate system is found to be accompanied by an increase in the microhardness of the deposited metal to 8.4 GPa, which is 2.8 times higher than the microhardness of the substrate (30KhGSA steel). The microhardness of the deposited layer subjected to combined heat treatment is shown to be almost independent of the distance from the substrate. Irradiation of the deposited layer is accompanied by the formation of a ≈100-μm-thick surface hardened layer, which is caused by a quenching effect combining the refinement of grain and subgrain structures.