Wide-band laser cladding: wear and corrosion resistance of a Ni-based alloy

A novel wide-band laser cladding system with high cladding rate has been developed in the present paper. The system mainly consisted of a 5kW CO₂ laser, an automatic powder feeder and a wide-band scanning rotative polygon mirror which can produce a linear or rectangular focused laser beam. Using this system, a Ni-Cr-Si-B alloy powder was clad on the surface of type 321 austenitic stainless steel in order to improve its wear and corrosion resistance. The pitting corrosion, high temperature oxidation and wear tests were conducted in order to evaluate the properties of the laser clad layer. The results demonstrated that the clad layer can significantly improve the adhesive wear and pitting corrosion resistance of the substrate. Moreover, the clad layer exhibits good oxidation resistance, which is almost the same as that of GMR-235D Ni-based superalloy.