Classification of inoculants

Currently, there are hundreds of inoculants for cast iron. According to relevant research, pure silicon or pure ferro silicon has no inoculating effect. Elements such as Al and Ca contained in silicon play a very important role.

1. Ferro silicon inoculant containing strontium
When the content of strontium in silicon is 0.6-1.0%, the inoculation effect is better. The graphitization ability is strong, which is twice that of ordinary ferro silicon. Increasing the number of eutectic groups is not significant, so it can reduce the densification and shrinkage tendency of iron castings, and has special significance for preventing shrinkage and leakage of iron castings such as cylinder blocks and cylinder heads.
It is suitable for thin-walled iron castings, with low cross-section sensitivity, uniform structure and uniform hardness. It can also be used for nodular cast iron, which is very effective in preventing white spots on thin-walled parts, but according to research, it is not suitable for cerium-containing cast iron. 2. Barium ferro silicon inoculant
The inoculation effect is very significant, it can increase the eutectic group, promote A-type graphite, reduce and uniform hardness, remove white spots and free cementite, resist recession, and improve cross-section sensitivity. The characteristic is not high efficiency, but long-term.
Suitable for thin-walled gray cast iron parts, such as cylinder block, cylinder head, etc. It is required that there are no white spots or uneven cross sections, and it is required to be dense. It is also suitable for ductile iron. After using barium-containing inoculant, graphite balls have high dispersion and high spheroidization rate.

3. Zirconium ferro silicon inoculant
Zirconium deoxidation and sulfur removal can improve the fluidity of molten iron, resist decay, increase eutectic groups, and promote uniform and fine A-type graphite. It can be used in conjunction with Ba and Ti to improve nucleation and graphitization capabilities. Suitable for a wide temperature range. 4. Titanium ferro silicon inoculant
For thin-walled gray iron castings, anti-whitening is very effective. Ti has a strong deoxidation and nitrogen fixation effect, which is beneficial to prevent nitrogen holes caused by charge or binder.
When used in gray cast iron, it should be considered that Ti has a strong promotion effect on D-type graphite; it is suitable for vermicular graphite cast iron; it is not suitable for ductile cast iron.