Analysis on property and microstructure of Mo-Si composite coating deposited by argon shielded arc on Q235 steel surface

Metal-silicide composite coating of FeMoSi/Fei₃Si was prepared by in situ synthesis on the surface of Q235 steel by means of argon arc cladding technique with the pre-alloyed powder of Mo and Si.The microstructure and phases of coating were investigated by scanning electron microscope(SEM) and X-ray diffraction(XRD), meanwhile the microhardness and the wear resistance of coating were tested.The results show that the interface between the coating and substrate has excellent bonding and is free of pores and cracks.Microstructure of the coating is mainly composed of α-Fe, primary dendrite FeMoSi and interdendritic FeMoSi/Fe₃Si eutectic structure.The microhardness was 3 times higher than that of Q235 steel and the maximum microhardness can reach 1 000 HV0.2, the wear resistance of coating was 11 times higher than that of Q235 steel substrate.