Research On The Manufacturing Process, Microstructure And Mechanical Properties Of WC/Steel-Based Composites Made By Electroslag Melting And Casting Method

Microstructure analysis showed that the tungsten carbide particle reinforced steel matrix composites, which were made by electroslag melting and casting method, not only had low content of porosity and nonmetal inclusion, but also could reduce the free carbon content immensely. Meanwhile, the new manufacturing process could solve the problem of tungsten carbide particle aggregation efficiently. It was proved that the electroslag melting and casting method had a remarkable priority compared with other composites manufacturing processes.During the manufacturing process, tungsten carbide particles were partly melted because of the high temperature. The melted tungsten carbide would react with the steel matrix on the interface and the reaction zone was observed as a result. The reacting production was examined as Fe3W3C by means of X-ray diffraction and scanning electron microscopy analysis. The reaction between tungsten particle and steel matrix could improve the interfacial bonding strength remarkably.Some abnormal microstructures in the tungsten carbide particle reinforced steel matrix composites were observed as the tungsten particulate content was increased. Experimental results showed that annealing and forging treatment could decrease the abnormal microstructure and improve the mechanical properties of the composites accordingly.Cross section morphology analysis showed that the fracture appearance of tungsten carbide particle reinforced steel matrix composites was a mixture of quasi-cleavage fracture and toughness fracture. The fracture appearance of tungsten carbide particle always displayed as quasi-cleavage fracture, while the cross section morphology of steel matrix transformed with the heat treatment techniques.The wear mechanism of tungsten carbide particle reinforced steel matrix composites was studied according to the frictional and wear characteristics and the scanning electron microscopy photographs of worn surfaces after wear testing. The effect of heat treatment and tungsten carbide content on wear resistance was investigated as well.