During the casting process of grey iron, various inoculants and nodulizers can be added to improve the quality of the final product. Inoculants are materials that are added to molten metal in order to control the formation of graphite and other microstructures. Nodulizers, on the other hand, are added to cast iron to promote the formation of nodular graphite, which can improve the mechanical properties of the final product.

One common inoculant for grey iron is Ferro Silicon (FeSi). FeSi is a type of alloy that contains iron and silicon, and it is commonly added to cast iron to promote the formation of graphite. Another inoculant that is sometimes used is Ferro Silicon Barium (FeSiBa), which contains barium in addition to iron and silicon. FeSiBa can help to improve the machinability and wear resistance of grey iron.

Nodulizers are materials that are added to molten cast iron in order to promote the formation of nodular graphite. Nodular graphite, also known as spheroidal graphite or ductile iron, is a type of graphite that is shaped like spheres or nodules. This microstructure is different from the flaky, irregular graphite that is found in grey iron, and it has a significant impact on the mechanical properties of the final product.

The use of nodulizers in the casting process of grey iron can help to improve the mechanical properties of the final product, making it stronger and more ductile. This is because nodular graphite is more resistant to crack propagation than flaky graphite, which can lead to improved toughness and fatigue resistance.

One of the most common nodulizers used in the casting process of grey iron is Ferro Silicon Magnesium (FeSiMg). FeSiMg is an alloy that contains iron, silicon, and magnesium, and it is added to molten cast iron in order to promote the formation of nodular graphite. The magnesium in FeSiMg reacts with the sulfur and oxygen in the molten metal, forming magnesium sulfide and magnesium oxide. These compounds act as nucleation sites for the formation of nodular graphite, which grows around them in a spherical shape.

FeSiMg is typically added to molten cast iron in amounts ranging from 0.03% to 0.06% by weight. The exact amount used will depend on factors such as the composition of the cast iron, the desired properties of the final product, and the casting conditions.

In addition to FeSiMg, other nodulizers that may be used in the casting process of grey iron include Ferro Silicon Strontium (FeSiSr) and Ferro Silicon Zirconium (FeSiZr). FeSiSr contains strontium in addition to iron and silicon, while FeSiZr contains zirconium. Both of these nodulizers can help to promote the formation of nodular graphite, improving the mechanical properties of the final product.

In conclusion, nodulizers are an important component of the casting process for grey iron. By promoting the formation of nodular graphite, they can help to improve the mechanical properties of the final product, making it stronger and more ductile. FeSiMg is one of the most common nodulizers used in this process, although other materials such as FeSiSr and FeSiZr may also be used depending on the desired properties of the final product.