单道激光熔覆Ni基合金涂层的组织与性能研究

Microstructure and property of single track laser cladding Ni-based alloy

采用10kW高功率连续CO2横流激光器在Cr12MoV模具钢表面单道熔覆Ni60AA合金粉末,研究不同激光工艺参数对熔覆层组织和硬度的影响,利用光学显微镜观察熔覆层显微组织,并用自动转塔显微硬度计测量熔覆层显微硬度.结果表明:激光功率的大小对热影响区附近的显微硬度影响不大,扫描速度为400 mm/min时熔覆层次表层硬度可以达到856 HV0.2.熔覆层主要相组织是富Ni的γ-Ni奥氏体枝晶和多元共晶的混合组织,Cr,B等元素的碳化物硬质相弥散分布在基体上.

In order to study the influence of laser power, scanning speed on the microstructure and mechanical properties of Crl2MoV steel in the process of single-pass cladding, Ni-based cladding layer on the die block steel was obtained by laser cladding technology by using a transversely-excited flowing 10kW CO2 laser. The microstructure of laser cladding layer was investigated by means of OM, and the microhardness was measured by automatic turret microhardness meter. The results showed that laser powder has hardly effect on microhardness of the heat-affected zone, the hardness of the subsurface layer reaches 856HV0.2 at an scanning rate of 400 mm per minute. Ni-rich austenite and multivariate eutectic, the carbide hard phase of B4C, Cr2C3 , etc dispersed through the metal matrix.