Influence of Diffusion and Wetting on the SiC Reinforcement of the Cast Surface of Low Alloy Steel

Reinforcement of a cast surface using a hard refractory material was used to obtain the desirable combination of toughness and wear resistance on the cast surface of a low alloy steel. Silicon carbide was chosen for its hardness and cost-effectiveness to reinforce the casting surface. The parameters that affect its interaction with the molten steel are still an issue of debate. The surface properties of the molten steel and the activity of silicon carbide have been proposed as the effective parameters in controlling the interaction between the molten steel and the solid silicon carbide. This research aims to define the role of each parameter on the SiC reinforcement of the casting surface. These two parameters were studied together and separately to identify the effect of each parameter on the depth of the composite layer, the constituent phases of microstructure and the wear adhesion resistance. It was found that the dissolved oxygen in the molten steel significantly affected the depth of the composite structure layer. The addition of chromium had a great effect in producing a crack-free interface structure. The low oxygen content of steel in combination with the high percentage of active element at the composite structure increased the wear resistance of the surface of the low alloy steel (AISI1020) tenfold.