激光熔覆无碳Fe-Co-Mo高速钢涂层的组织结构与性能

用水雾化合金粉末为原料,通过同步送粉式激光熔覆技术在40Cr基材上制备无碳高速钢涂层,对涂层的显微硬度、红硬性和抗回火稳定性进行测试和分析,研究工艺参数对涂层形貌及硬度的影响。结果表明,在适宜的参数下能够在基材表面获得无宏观裂纹和气孔的无碳高速钢涂层。涂层致密度高、稀释率低,与基体呈现出良好的冶金结合。涂层熔覆态下显微硬度(HV0.2)达到700,经过600℃下1 h时效后,涂层硬度(HV0.2)明显提升至900。经过4次600℃保温1 h的时效后,涂层硬度(HV0.2)保持在800。此外在600℃保温30 h的长时间回火后,涂层仍然可以保持硬度(HV0.2)达750,相较于常规高速钢ASP2030以及热作模具钢H13具有更加出色的抗回火能力。

Microstructure and properties of carbon-free Fe-Co-Mo high speed steel coating prepared by laser cladding

Carbon-free high-speed steel coatings were prepared on 40Cr substrates by synchronous powder-feeding laser cladding technology with water atomized alloy powder as raw material.The microhardness,red hardness and tempering resistance of the coating were tested and analyzed.The effects of process parameters on the morphology and hardness of the coating were studied.The results show that,under suitable parameters,a carbon-free high-speed steel coating without macro cracks and pores was obtained on the surface of the substrate.The coating has high density and low dilution rate,and exhibits a good metallurgical bond with the substrate.The microhardness(HV0.2)of the coating in the cladding state is 700,and the coating hardness(HV0.2)is significantly increased to 900 after aging at 600℃for 1 h.After aging at 600℃for 1 h for 4 times,the coating hardness(HV0.2)remains at 800.In addition,after a long time tempering at 600℃for 30 h,the coating can still maintain a hardness(HV0.2)of 750,which has better tempering resistance than conventional high-speed steel ASP2030 and hot work die steel H13.