Ductile cast iron is a kind of high strength cast iron material developed in the 1950s. Its comprehensive performance is close to steel. It is based on its excellent performance that it has been successfully used for casting some parts with complex force, high strength, toughness and wear resistance. Ductile iron has rapidly developed into a widely used cast iron material second only to grey cast iron. The so-called “steel instead of steel”, mainly refers to ductile iron.

Ducular iron is spherical graphite through spherulation and gestation treatment, which effectively improves the mechanical properties of cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel.

Cast iron is a carbon content of more than 2.11% of iron carbon alloy, by industrial pig iron, scrap steel and its alloy materials after high temperature melting and casting forming, in addition to Fe, carbon and other cast iron in graphite form, if the precipitation of graphite strip of cast iron called gray cast iron or gray cast iron, worm cast iron called worm ink iron, a group of cast iron called white cast iron or code iron, and spherical cast iron is called spherical ink cast iron.

The chemical composition of ductile iron except iron is usually: carbon content 3.0~4.0%, silicon content 1.8~3.2%, manganese, phosphorus, sulfur total not exceed 3.0% and appropriate amount of rare earth, magnesium and other globtized elements.