喷射成形与传统熔炼高速钢M2的组织与力学性能研究

通过喷射成形和传统熔炼（中频冶炼+电渣重熔）两种工艺生产了高速钢M2（W6Mo5Cr4V2）试样，利用金相显微镜和M-200磨损试验机对同规格同位置的两种试样的退火组织、非金属夹杂物、淬回火硬度、显微组织和力学性能进行了研究。结果表明，喷射成形M2试样的碳化物分布均匀、尺寸细小，传统熔炼M2试样碳化物呈条带状分布；在相同热处理制度和位置下，喷射成形M2试样的回火硬度与传统熔炼M2试样相当；喷射成形M2试样的耐磨性要比传统M2试样提高约41%；喷射成形M2试样中尺寸大于2μm的MC类碳化物数量明显多于传统M2试样，使得在同等硬度下喷射成形M2试样的耐磨性能要优于传统M2试样。由此可知，喷射成形M2试样的组织及力学性能均优于传统熔炼M2试样，喷射成形技术具有工艺先进性。

Research on the microstructures and mechanical properties of high speed steel M2 produced by spray forming and traditional melting

Two kinds of high speed steel specimens (M2, W6Mo5Cr4V2) were prepared by spray forming and traditional melting, respectively. The annealing structures, non-metal inclusions, hardness after quenching and tempering, microstructures, and mechanical properties of M2 specimens in the same size at the same location were studied by metallographic microscope and M-200 wear tester. In the results, the carbides in spray formed M2 specimens show more uniform distribution and smaller size, and the carbides in traditional melted M2 specimens are present as the zonal distribution. In the same heat treatment process, the tempering hardness of M2 specimens prepared by spray forming and traditional melting is similar at the same location. Compared with the traditional melted M2 specimens, the wear resistance of spray formed M2 specimens is increased by ~41%. The number of MC carbides in spray formed M2 specimens with the size more than 2μm is apparently higher than that in the traditional melted M2 specimens, resulting in the higher wear resistance of spray formed M2 specimens in the same hardness. It can be seen that the microstructures and mechanical properties of spray formed M2 specimens are better than those of the traditional melted M2 specimens, showing the advancement of spray forming technology.