球墨铸铁中的硅是一个比较重要的元素,它控制着所生成的石墨的数量及基体的形式,因此,它对球铁的物理机械性能有深刻的影响。但是控制硅的含量是比较困难的,因为生产中的每一个环节都有可能导致硅的增加。使用较多的返回料;加入硅铁镁合金和加入孕育剂,都易于导致硅的增加。除薄壁铸件和铁素体基体铸件外,一般提高硅含量会引起延伸率,冲击韧性、特别是低温冲击韧性的降低。控制硅含量的办法是:降低炉料中返回料的用量,减少球化剂和孕育剂的加入量。降低返回料的加入量在经济上是不合理的,另外硅含量低的铁水对用二氧化硅作炉衬的无芯感应炉衬 Silicon in ductile iron is a relatively important element that controls the amount of graphite produced and the form of the matrix, so it has a profound effect on the physical and mechanical properties of the ductile iron. However, controlling the silicon content is more difficult because every step in production can lead to increased silicon. Use more return material; adding ferrosilicon magnesium alloy and adding inoculant, are easy to lead to the increase of silicon. In addition to thin-walled castings and ferritic base castings, generally increasing the silicon content causes elongation, impact toughness, and in particular, low-temperature impact toughness. The way to control the silicon content is to reduce the amount of material returned in the charge and to reduce the addition of nodulizers and inoculants. Reduce the amount of return material added is economically unreasonable, the other low-silicon content of molten steel on the lining of silica-coreless induction lining