铁—碳系合金的石墨化有八种型式。图1为Fe—C系合金的双重状态图。过共晶成分的铁水,温度一经下降到碳溶解度线(在硅量高时,只考虑石墨溶解度线)以下,铁水中便析出石墨,即产生石墨化。当冷却速度特別小时,铁水中所生成的石墨结晶有逐渐上浮的倾向,当添加硅量高时,铁水中碳的过饱和度 There are eight types of graphitization of iron-carbon based alloys. Figure 1 shows the dual state of Fe-C alloy. Hypereutectic composition of hot metal, once the temperature dropped to the carbon solubility line (in the silicon is high, only consider the solubility of graphite line) below, the precipitation of graphite in the molten iron, that is, graphitization. When the cooling rate is particularly small, the graphite crystallized in hot metal tends to float upward. When the amount of silicon added is high, the supersaturation of carbon in hot metal