Microstructure and Properties of Cr₃Si/γ-Fe Composite Coating Prepared by Plasma Transferred Arc Cladding Technique

Under optimized operating parameters, a wear and corrosion resistant Cr₃Si/γ-Fe composite coating is fabricated on a normalized 0.45% carbon steel substrate by using the plasma transferred arc (PTA) cladding technique with Fe-Cr-Si elemental powder blend as the precursor material. Microstructure, microhardness, dry-sliding wear resistance and electrochemical corrosion characteristic of the coating are evaluated. Test results show that the composite coating is mainly composed of primary Cr₃Si dendrites and the interdendritic supersaturated iron-base solid solution γ-Fe. Between the Cr₃Si/γ-Fe composite coating and the normalized 0.45% carbon steel substrate, there is a narrow metallurgical bonding zone. The Cr₃Si/γ-Fe composite coating exhibits high microhardness, excellent wear and corrosion resistance under test conditions.