Inoculants act in ductile iron, mainly have the following roles:
First, to promote the formation of graphitization, reduce the tendency of white mouth;
Second, refine the grain, reduce segregation, uniform organization, to avoid the emergence of supercooling organization;
Third, improve mechanical strength, light cast iron wall thickness sensitivity, so that the casting of thin and thick cross-section at the microstructure of the difference is small, hardness difference is also small;
Fourth, in favor of eutectic group nucleation, so that the number of eutectic groups increased;
Fifth, so that the form of graphite in cast iron is mainly fine and uniformly distributed A-type graphite, thus improving the mechanical properties of cast iron.