Effects of Si on microstructures and properties of in situ WC reinforced coating

Effects of Si on microstructures and properties of WC particles reinforced coating with Si content from 0 to 12.5 wt-% prepared by argon arc cladding were analyzed by optical microscopy, scanning electron microscopy (SEM), X-ray diffractometer (XRD), hardness tester and wear tester. The results show that, when Si content is in range of 0 to 5 wt-%, it can promote the nucleation and growth of the WC and inhibit the growth of Fe₃W₃C. When Si is added to 5 wt-%, the wear resistance of the coating was 58 times than that of Q235 steel, which was corresponding to WC particles distributing uniformly in the coating. However, as the Si content increased up to 7.5 wt-%, the wear resistance was only 13.9 times than that of Q235 steel due to the WC grain size decreasing and obvious aggregation.