Microstructure and Tribological Properties of Fe-Based Composite Coatings Prepared by High-Velocity Arc Spraying

This study comes within the context of wear-resistant coatings and remanufacturing of shaft parts. It used FeMnCrNi and FeMnCrNi-Cr3C2 coatings deposited on the surface of Q235 steel by high-velocity arc spraying. The microstructure and mechanical properties of the coatings were studied and analyzed by scanning electron microscopy, energy dispersive spectrometry, x-ray diffraction (XRD), microhardness testing and an electronic universal testing machine. The FeMnCrNi coating consisted of α-(Fe, Cr) and Fe3O4 phases, while the FeMnCrNi-Cr3C2 coating consisted of γ-(Fe, Ni), α-(Fe, Cr), Fe3O4 phases and a Cr3C2 hard phase. The tensile bond strengths of the FeMnCrNi and FeMnCrNi-Cr3C2 coatings were 31 ± 4 MPa and 27 ± 1 MPa, respectively. The microhardness of the FeMnCrNi-Cr3C2 coating was 694 ± 82 HV0.1, 3.1 times higher than that of Q235 steel and 1.8 times that of the FeMnCrNi coating. The wear behavior of the coatings and substrate under different loads was studied by a material surface performance comprehensive tester. The results indicated that their wear rates increased with increasing load. Compared to the FeMnCrNi coating and Q235 steel, the FeMnCrNi-Cr3C2 coating had the lowest wear rate under different loads. The main wear mechanism of the FeMnCrNi-Cr3C2 coating was surface fatigue and abrasive wear.