Low magnesium spheroidizing line: Ductile iron castings are widely used in the fields of automobile, machine and equipment manufacturing. There are various types of spheroidizing agents used in the production of ductile iron. At present, master alloys containing magnesium and rare earth are mainly used as spheroidizing wires in production. There are also some other spheroidized wires, such as pure magnesium, mechanical mixtures containing magnesium. The selection of spheroidizing line and spheroidizing treatment method mainly depends on production conditions, casting performance, etc. The main chemical components of the spheroidized wire are Mg5~10%; Re0~2%; Si0~10%, and the balance is iron. The composition is Mg5-9%, Re0.5-3%, Ca3.5-5.0%, Ba1.5-4.5%, Si35-50%, Bi0.5-4.5%, and the rest is iron. The spheroidizing line contains a large amount of metallic magnesium, which seriously restricts the production of low silicon ductile iron.