Silicon is the most important alloying element after manganese in pig iron and carbon steel. Silicon is mainly used as a deoxidizer for molten metal, or as an alloying additive to increase the strength and improve the properties of steel. Silicon is also an effective stone-grinding medium, which turns carbon in cast iron into free stone-grinding carbon. The silicon added to standard gray cast iron and ductile iron can reach 4%, so silicon-manganese balls have also become an important material in steelmaking and deoxidation, and silicon-manganese balls have also become a necessary metallurgical material.