65Mn 钢表面激光熔覆温度场模拟及性能研究

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.