Characterization and wear behavior analysis of tungsten carbide-nickel cladding deposited on carbon steel by GTAW

This study investigates the effect of a tungsten carbide-nickel coating on the wear resistance of plain carbon steel. The primary phases identified in the coating were Fe3W3C, Fe4W2C, and a eutectic structure containing Fe3W3C and (Fe–Ni)-α. Wear behavior was evaluated through a friction coefficient test and Scanning Electron Microscopy (SEM) analysis. The coated samples exhibited a significantly lower friction coefficient compared to the uncoated sample, indicating superior wear resistance. This improvement is attributed to the presence of a network of (Fe, W)3C carbides and the strong interfacial bonding between the coating and substrate. Coated surfaces displayed parallel scratches and small wear particles, indicative of a scratch-type wear mechanism. Microhardness measurements revealed a distinct profile across the coating thickness. The high hardness near the surface is attributed to the presence of simple carbides. Hardness increased further in the center of the coating due to optimized welding parameters. Hardness decreased towards the interface with the substrate due to a decrease in alloying elements and a shift towards complex carbides.