Microstructure and wear behavior of (Cr,Fe)7C3 reinforced composite coating produced by plasma transferred arc weld-surfacing process

A wear-resistant (Cr,Fe)7C3 carbide reinforced composite coating was fabricated on substrate of a 0.45% C carbon steel by plasma transferred arc (PTA) weld-surfacing process using Fe–Cr–C–Ni powder blends. The microstructure, microhardness and dry-sliding wear behavior of the composite coating were investigated using optical micrograph (OM), X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and ring-on-ring wear tester. Results show that the composite coating consists of primary (Cr,Fe)7C3 as the reinforcing phase and interdendritic (Cr,Fe)7C3/γ-Fe eutectics as the matrix. The composite coating is metallurgically bonded to the 0.45% C carbon steel substrate. The (Cr,Fe)7C3 carbide reinforced composite coating has high hardness and excellent wear resistance under dry sliding wear test conditions.