company news about The Specific Role Of Silicon In Cast Iron In Silicon Powder

Silicon promotes graphitization in cast iron. In cast iron, silicon is an alloy element that promotes graphitization. Its ability to promote graphitization is three times that of nickel and five times that of copper. And whether in liquid or solid cast iron, the combination of silicon and iron is stronger than carbon. In addition, liquid cast iron contains silicon, which reduces the solubility of carbon. The higher the silicon content in the molten iron and the lower the carbon content, the more carbon will be squeezed out.

When the molten iron is a hypereutectic composition, the silicon content is high. During the solidification process, more carbon is precipitated in the form of primary graphite until the remaining molten iron reaches a eutectic composition and undergoes eutectic transformation; the molten iron is hypoeutectic. When the crystal composition is high, silicon is enriched in primary austenite during the solidification process. During the eutectic transformation, silicon is enriched in the early crystallized eutectic austenite, inhibiting the synthesis of cementite from carbon and iron, enhancing the diffusion rate of carbon in austenite, and promoting the precipitation of carbon in the form of eutectic graphite; During the eutectoid transformation, the solid solution of silicon in austenite still inhibits the formation of cementite between carbon and iron, enhances the diffusion rate of carbon in austenite, and promotes the precipitation of carbon in the form of eutectoid graphite.