Ductile iron parts can be modified by various heat treatments and can be used in almost all major industrial fields. These sectors require high strength, ductility, toughness, wear resistance, resistance to severe thermal and mechanical shocks, high or low temperatures, and resistance. Corrosion and dimensional stability. Spherical graphite castings are widely used cast iron materials. The carbon in the cast iron is precipitated in the form of graphite. If the precipitated graphite is in the form of a strip, the cast iron is called gray cast iron or gray cast iron, and the cast iron in the form of a worm is called worm cast iron. When the flocculated cast iron is called white cast iron or coded iron, the spherical cast iron is called a ductile iron piece.
    (1) The chemical composition of strict requirements, the carbon and silicon content of the original iron liquid is higher than that of gray cast iron, which reduces the content of manganese, phosphorus and sulfur in the ductile iron.
    (2) The temperature of the molten iron is higher than the temperature of the gray cast iron to compensate for the loss of spheroidization and molten iron temperature during the treatment.
    (3) Spheroidizing treatment by adding a spheroidizing agent to molten iron.
    (4) Ductile iron castings have poor fluidity and large shrinkage, so high pouring temperature and large casting system size are required. Reasonable application of riser and cold iron adopts the principle of sequential solidification.
    (5) Perform heat treatment.