Microstructure and property of WC/steel matrix composites

Abstract

Steel matrix composites (SMCs) with 5CrNiMo steel as matrix and tugnsten carbide (WC) particles as hard phase were prepared by inductive electroslag casting technology. The influence of annealing, forging state and quenching tempering state on the microstructures of the particle-reinforced SMCs were investigated by metallographic analysis method. The particle composition and the composition change of the boundary were tested by energy dispersive X-ray spectroscopy with the scanning electron microscope, and the macro and microhardness were determined by Rockwell hardness tester and microhardness tester. The results show that in most parts of the SMCs, the distribution of WC particles was relatively uniform. White WC particles wrapped around a circle of black stripe Fe3W3C compound carbides. A certain thickness of the transition layer existed on the interface of the WC particle and steel matrix, and two kinds of WC grains for ‘iron rich’ and ‘iron poor’ appeared. The macro and microhardness of the composite material improved significantly than that of the 5CrNiMo steel after inductive electroslag casting.