Spheroidal graphite cast iron, spheroidizing and inoculating treatment to obtain spherical graphite, which effectively improves the mechanical properties of cast iron, especially improves the plasticity and toughness, thereby obtaining higher strength than carbon steel. It is said that ductile iron is a high-strength cast iron material developed in the 1950s. Its comprehensive performance is almost close to that of steel. It is based on its excellent performance that it has been successfully used to cast some complex stress, strength, toughness, Parts requiring high wear resistance. Ductile iron has rapidly developed into a cast iron material that is second only to gray cast iron and is widely used. The so-called "replace steel with iron" mainly refers to ductile iron.