Microstructure and Corrosion Behavior of In-situ Synthesized Cr7C3 Ceramic Coating Prepared by Laser Cladding

Cr7C3 ceramic coating was prepared on the surface of Q235 steel by laser cladding. Optical microscopy, X-ray diffraction, scanning electron microscopy and polarization curves combined with static immersion testing were used to analyze the microstructure and corrosion resistance of cladding layer. The results show that the surface of cladding layer was smooth and had no crack and hole. The metallurgical bonding between the cladding layer and surface of substrate was good and the shapes of ceramic particles were stripy and blocky. The current density of cladding layer was about half of the base material, indicating that the cladding layer has good corrosion resistance.