（1） The chemical composition is strictly required. The carbon and silicon content of raw molten iron is higher than that of gray cast iron, and the content of manganese, phosphorus and sulfur in nodular cast iron is reduced.
（2） The tapping temperature of molten iron is higher than that of gray cast iron to compensate for the loss of molten iron temperature during spheroidization and inoculation treatment.
（3） Carry out spheroidizing treatment, that is, add spheroidizing agent to molten iron.
（4） Inoculant is added for inoculation treatment.
（5） Nodular cast iron has poor fluidity and large shrinkage, so it needs higher pouring temperature and larger pouring system size. The riser and cold iron shall be reasonably applied and the principle of sequential solidification shall be adopted.
（6） Heat treatment.
① Annealing. Obtain ferrite matrix, improve plasticity and toughness, eliminate stress and improve cutting performance.
② Normalize. Pearlite matrix is obtained to improve strength and wear resistance.
③ Conditioning. Obtain the matrix structure of tempered sorbite and good comprehensive mechanical properties, such as spindle, crankshaft, connecting rod and so on.
④ Isothermal quenching. Make the parts with complex shape and high comprehensive performance requirements obtain the matrix structure of lower bainite and comprehensive mechanical properties such as high strength, high hardness and high toughness, so as to avoid cracking during heat treatment, such as spindle, crankshaft, gear, etc.