Study on Microstructure and Wear Resistance of Fe-based Coating Laser-cladded on Surface of 316L Austenitic Stainless Steel

Fe-based multi-channel lap cladding layers with different WC contents and different TiC contents were prepared on 316L stainless steel surface by laser cladding technology and coaxial powder feeding method. The results show that the macroscopic quality of the laser cladding layer is better when the laser power is 1200 W, the scanning speed is 5 mm/s, the spot size is 2 mm, the defocusing amount is 19 mm, and the powders feeding speed is 0.15 g/s. The microstructure growth characteristics of each cladding layer are relatively similar when adding WC or TiC powders to the iron base alloy powder. The melt solidification forms at the junction between the cladding layer and the matrix is planar crystal, the bottom of the cladding layer is a cellular crystal, the middle part is columnar dendrite, and the top is equiaxed dendrite. After adding WC or TiC to the Fe-based powders, the grains in the cladding layer are refined, and the hardness and wear resistance of the cladding layer are improved. TiC-reinforced composite coating exhibits better hardness and friction-wear properties when adding the same content of WC and TiC powders.