Preparation, Microstructure and Properties of Plasma Arc Cladding Layer with WC Reinforced Iron-Based Alloy Powder-Cored Hot Wire

WC reinforced iron-based alloy cladding layer was prepared by heating WC reinforced iron-based alloy powder-cored wire with resistance heat and plasma arc dual heat source simultaneously. The macromorphology, microstructure and properties of cladding layers under different hot wire currents (0,40,50,60,70 A) were studied, and the appropriate hot wire current was obtained. The results show that when the hot wire current was 50 A, the forming quality of the cladding layers was good with the lowest dilution rate of 51.77%. With increasing hot wire current, the average grain size of the cladding layer first decreased and then increased, and the carbide content first increased and then decreased. When the hot wire current was 50 A, the microstructure mainly consisted of fine cellular austenite, the average grain size was small (9.45 μm), and the carbide content was the highest. With increasing hot wire current, the average hardness of the cladding layer first increased and then decreased, and the wear rate and friction coefficient first decreased and then increased. When the hot wire current was 50 A, the cladding layer had the highest average hardness of 403.1 HV, the smallest friction coefficient of 0.52 and the smallest wear rate of 4.53×10^-6 mm³·N^-1·m^-1.