Effects of laser power on performance of cladding Ni-based alloy coating on surface of butterfly valve

The effect of laser power on the dilution rate, microstructure, corrosion resistance and hardness of the coating were investigated by adopting semiconductor laser to laser clad Ni based alloy coating on 2205 duplex stainless steel and by means of SEM, electrochemical synthesis tester and hardness tester. The results show that dilution rate of the coatings increases with the increase of the laser power and there is more convection and diffusion of the cladding layer and the matrix elements; cladding layer resistance corrosion resistance decreases with the increase of the laser power when laser power is 2.7 kW, the cladding layer of the self corrosion potential is -0.46 mV which is at minimum, and corrosion current is 3.47×10^-5 A/cm² which is at minimum. The hardness test results show that the hardness of the laser clad Ni based alloy coating is up to 680 HV, which is about 2.5 times that of the matrix alloy.