Why is iron easily broken?
Iron in addition to iron, but also contains carbon, silicon, manganese, phosphorus and sulfur and other elements. These elements have some impact on the performance of pig ironCarbon (C) exists in two forms: one is in pig iron, free carbon (graphite), mainly in the cast iron, the other is a combined carbon (Tan Huatie), mainly in the steel-making pig iron, Tan Huatie hard and brittle, low plasticity, appropriate content can improve the strength and hardness pig iron, the iron content is too much, it is difficult to cut processing, steel-making pig iron causes poor cutting performance. The graphite is soft, low intensity, it can increase the performance of pig iron casting.Silicon (Si): to make pig iron contained in the graphite like carbon sequestration, can also reduce the air oxygen, casting, can improve the fluidity of molten pig iron to reduce the casting shrinkage, but silicon containing too much, also make iron brittle and hard.
Generally less than 0.2% carbon content that wrought iron or iron, the content of 0.2-1.7% in the steel, content of more than 1.7% is iron. Iron soft, good plasticity, easy deformation, strength and hardness were lower, not widely used; iron carbon, hard and brittle, almost no plastic.
Manganese (Mn): can be dissolved in ferrite and cementite. In blast furnace refining iron, manganese content is proper, can improve the performance of pig iron casting and cutting performance of manganese in the blast furnace can also be harmful impurities and sulfur formation of manganese sulfide into slag.P (P), belongs to the harmful elements, but phosphorus can make molten iron flow increases, this is because the pig iron to reduce the sulfur melting point, so in some products, often with high phosphorus. However, the existence of phosphorus and iron increase of brittle iron, phosphorus content should be less good, sometimes in order to increase liquidity the phosphorus content of up to 1.2%..Sulfur (S): in the pig iron is a harmful element, it promotes the combination of iron and carbon, the iron hard brittle, iron sulfide and chemical synthesis of low melting point and iron, the brittle cast iron heat generated and reduce the mobility of liquid iron, iron Gu high sulfur is not suitable for fine casting. Casting iron content requirements the sulfur shall not exceed 0.06% (except iron wheels).
