Effect of powder feeding rate on microstructure and properties of Fe-based fine-grained lasers cladding layers

This manuscript investigates the influence of powder feeding rate on the microstructure and properties of vanadium carbide-reinforced fine-grained cladding layers fabricated on nodular cast iron by laser cladding. The results indicate that as the powder feeding rate increases, the crack defects in the cladding layer are significantly improved. All cladding layers are composed of α-Fe and in-situ synthesized vanadium carbide. With the increase in powder feeding rate, the proportion of in-situ synthesized vanadium carbide relatively decreases. The hardness of the cladding layer exhibits a trend of initially increasing and then decreasing with the increase in powder feeding rate. The corrosion resistance of the cladding layer enhances with the increase in powder feeding rate. When the powder feeding rate reaches 6 g/min, the cladding layer demonstrates the best comprehensive performance, including good formation as well as excellent hardness and corrosion resistance.