Ductile iron is a kind of high-strength cast iron material developed in the 1950s. Its comprehensive performance is close to that of steel. It is based on its excellent performance and has been successfully used for casting some complex forces, strength, toughness and wear resistance. Parts with higher requirements. Ductile iron has rapidly developed into a widely used cast iron material after gray cast iron. The so-called "iron-based steel" mainly refers to ductile iron. The cast iron is obtained by spheroidizing and inoculation to obtain spheroidal graphite, which effectively improves the mechanical properties of the cast iron, in particular, improves the ductility and toughness, thereby obtaining higher strength than the carbon steel.