75sife alloy is the most widely used inoculant at home and abroad. The composite inoculant composed of Ca, Ba, Sr and rare earth elements added on the basis of 75sife alloy can prolong the inoculation decay time and improve the microstructure and properties of castings, especially for large section ductile iron castings.

(1) Primary inoculation: inoculation by covering inoculant on nodularizing agent;

(2) Secondary inoculation: also known as instantaneous inoculation. According to the characteristics of secondary inoculation process, it can be divided into the following inoculation processes:

① Sprue cup inoculation: inoculate the inoculant in the sprue cup.

② Stream inoculation: an inoculation method to make the inoculant enter the mold with the molten iron within a specified time.

③ Inoculation of inoculated silk: the inoculation device of inoculated silk is the same as the operation and spheroidization of wire feeding method.

In addition, there are other inoculation processes, such as floating silicon inoculation, ladle inoculation, in mold inoculation block inoculation and so on.

Considering the spheroidization, inoculation process and the actual situation, the spheroidization process of the impact method, the compound inoculation process of the ladle inoculation and the stream inoculation were used in the experiment of the 45 ° fan-shaped block.