Adding silicon carbide during cast iron smelting. For gray cast iron, due to the pre-incubation effect of non-equilibrium graphite, the temperature at which a large number of eutectic clusters are formed and grown can be increased (reduce the relative undercooling), which is beneficial to the formation of A-type graphite; it can also be As the number of crystal nuclei increases, the flake graphite becomes smaller, increasing the degree of graphitization and reducing the tendency to whiten, thus improving the mechanical properties.

Correct time to add silicon carbide: Because the melting point of silicon carbide particles is high, the time to add silicon carbide is critical. If it is added too late, the silicon carbide will not all melt and diffuse, and the unmelted silicon carbide will be in the form of granules. Existing in the molten iron, slag eyes will be formed after the molten iron is poured; if the addition time is too long, the nucleation formed by silicon carbide will slowly disappear after the molten iron is smelted for a long time, which can only play a simple role. The silicon-increasing effect.