For the production of ferrite ductile iron, it is necessary to select high-purity raw materials. The content of Si, Mn, S and P in raw materials is less (Si<1.0%, Mn<0.3% S<0.03%, P<0.03%). ), some alloying elements such as Cu, Cr, Mo should be strictly controlled. Because many trace elements are most sensitive to spheroidization decline, such as tungsten, tantalum, tin, titanium, vanadium and so on. The influence of titanium on spheroidization should be controlled, but the high titanium is the characteristic of pig iron in China, which is mainly related to the metallurgical process of pig iron.