Carbon (C):

Cast iron exists in two forms, a free carbon (graphite), found primarily in the foundry pig iron, the other is a combined carbon (iron carbide), found primarily in the steel-making pig iron, iron carbide hard and brittle, low plasticity content appropriate, can improve the strength and hardness of the cast iron, the content is too large, then the cast iron is difficult to cutting process, which is steelmaking the PIG mach inability causes of poor. Graphite is very soft, low strength, its presence can increase the performance of cast iron casting.

Silicon (Si):

Carbon contained in cast iron can promote separation is a graphite-like, can deoxy, but also reduce the eyelet of the casting, can improve the flow of molten cast iron, and to reduce the amount of shrinkage of the casting, but the silicon-containing excessive, and also make the cast iron becomes hard brittle.

Manganese (Mn):

Can be dissolved in the ferrite and cementite. In when BF refining pig iron, manganese content is appropriate, the casting properties of the cast iron and the cutting of the performance can be improved and harmful sulfur impurities in the blast manganese can also form a manganese sulfide, into slag.

Phosphorus (P):

Are harmful elements, but the phosphorus of molten iron can be increased mobility, this is because of sulfur reduced the pig iron melting point, so often a higher phosphorus content in some products. However, the presence of phosphorus and iron increased brittle, the excellent phosphorus content of pig iron should be less, sometimes in order to increase the mobility of the phosphorus content of up to 1.2%.

Sulfur (S):

Harmful elements in the cast iron is, it contributes to a combination of iron and carbon, iron hard and brittle, and the iron synthesis with a low melting point of iron sulfide, pig iron to produce hot brittleness and reduce the fluidity of the liquid iron, Gu high sulfur iron not suitable for casting thin pieces. The casting of cast iron in the sulfur content of the provisions shall not exceed a maximum of 0.06%