various elements influence of pig iron

In addition to iron, pig iron also contains elements such as carbon, silicon, manganese, phosphorus and sulfur. These elements have a certain influence on the properties of pig iron.

（1）Carbon: There are two forms of carbon in pig iron, one is free carbon (graphite), which is mainly found in cast pig iron, and the other is compound carbon ( iron carbide), which is mainly found in steel-making pig iron. Iron carbide is hard, brittle and low plasticity, proper content can increase the strength and hardness of pig iron, too much content will make pig iron difficult to cut, this is the reason for the poor cutting performance of steel-making pig iron. The graphite is very soft and has low strength, its presence can increase the casting performance of pig iron.

(2)Silicon: It can promote the separation of the carbon contained in the pig iron into graphite, which can deoxidize, and can reduce the porosity of the casting, can improve the fluidity of the molten pig iron, and reduce the shrinkage of the casting, but too much silicon will also cause the pig iron to change hard and brittle.

(3)Manganese: It is soluble in ferrite and cementite, when smelting pig iron in a blast furnace, the appropriate content of manganese can improve the casting performance and cutting performance of the pig iron. In the blast furnace, manganese can also form manganese sulfide with sulfur impurities and enter the slag.

(4)Phosphorus: It is a harmful element, but phosphorus can increase the fluidity of molten iron, this is because sulfur reduces the melting point of pig iron, so some products tend to contain higher phosphorus. However, the presence of phosphorus increases the hardness and brittleness of iron. Good pig iron should contain less phosphorus. Sometimes in order to increae fluidity, the phosphorus content can reach 1.2%.

(5)Sulfur: It is a harmful element in pig iron. It promotes the combination of iron and carbon, makes iron hard and brittle, and combines with iron to form low-melting iron sulfide, which makes pig iron with hot brittleness, reduce the fluidity of molten iron, so the pig iron with high sulfur do not suitable for casting small parts. The sulfur content in cast pig iron shall not exceed 0.06% at most (except for wheel pig iron)

There are also some common impurity elements in steel and alloy steel that have different effects on them. Anyang Huatuo Metallurgy will update the relevant content one after another, if you need to contact us at any time.