Research on corrosion resistance and wear resistance of laser cladding Cr₃Si/γ multi-phase coating

The Cr₃Si/γ multi-phase intermetallic coating on a substrate of austenitic stainless steel 1Cr18Ni9Ti is in situ synthesized by laser cladding technique to investigate the microstructure and surface properties. Electrochemical corrosion resistance is examined by anodic polarization in the 3.5% (mass fraction) NaCl solution. Wear resistance is evaluated through mass loss of specimens in room-temperature dry sliding wear experiments. The micro failure mechanisms are investigated by optical microscope (OM), scanning electron microscope (SEM) and other test measurements. Results indicate that the laser cladding coating has a multi-phase microstructure. The hard phase Cr₃Si is distributed in the Ni-base solid solution (γ) matrix, contributing to the higher microhardness. In the 3.5% NaCl solution, the passive film forms spontaneously on the surface of the coating exhibiting excellent pitting corrosion resistance. The laser cladding coating exhibits better wear resistance for the less mass loss and the lower friction coefficient.