65Mn钢表面激光熔覆温度场模拟及性能研究

为了探究不同激光熔覆工艺参数对温度场的影响，利用ANSYS软件对激光熔覆温度场进行模拟。在选定工艺参数下，通过激光熔覆技术在65Mn钢表面熔覆Ni60A合金粉，并与镍基焊条电弧焊试验进行对比。对两种熔覆层的显微组织、显微硬度及摩擦磨损性能进行观察和测试。结果表明：激光熔覆温度场的最高温度与激光功率、频率成正比，而与扫描速度成反比。在激光功率580 W，扫描速度100 mm/min，频率4 Hz，脉宽8 ms的工况下，温度场最高温度达到2 092.1℃。激光熔覆层主要由等轴晶、柱状晶组成，而电弧焊覆层组织的晶粒组织粗大，存有大量树枝晶。激光熔覆层晶粒更加致密，组织均匀，强度、塑韧性性能更好。在硬度与耐磨性方面，激光熔覆层硬度平均值为531.24 HV_0.2，电弧焊熔覆层硬度平均值为492.46HV_0.2，且激光熔覆对硬度的提高效果更加显著。激光熔覆层的磨损率为4.9×10^-4 mm³·N^-1·m^-1，是基体的3/5。磨损机理由严重的粘着磨损转变为轻微的磨粒磨...

Simulation and Performance Research of Laser Cladding Temperature Field on 65Mn Steel Surface

In order to explore the influence of different laser cladding process parameters on the temperature field, the ANSYS software is used to simulate the temperature field of laser cladding. Under the selected process parameters, Ni60A alloy powder is clad on the surface of 65Mn steel by laser cladding, and compared with the Ni-based electrode arc welding test. The microstructure, microhardness and friction and wear properties of the two cladding layers are observed and tested. The results show that the maximum temperature of the laser cladding temperature field is proportional to the laser power and frequency, and inversely proportional to the scanning speed. Under the conditions of laser power 580 W, scanning speed 100 mm/min, frequency 4 Hz and pulse width 8 ms, the maximum temperature of the temperature field reached 2 092.1 ℃. The laser cladding layer is mainly composed of equiaxed crystals and columnar crystals, while the grain structure of the arc welding cladding layer is coarse and contains a large number of dendrites. The laser cladding coating had more dense grains, uniform structure, and better strength and plasticity. In terms of hardness and wear resistance, the average hardness of the laser cladding layer is 531.24 HV_0.2, and the average hardness of the arc welding cladding layer is 492.46 HV_0.2, and the effect of laser cladding on the hardness improvement is more significant. The wear rate of laser cladding layer was 4.9×10^-4 mm³·N^-1·m^-1 which was 3/5 of that of the substrate. The wear mechanism changed from severe adhesive wear to slight abrasive wear.