Heat-resistant cast iron is an important part of engineering technology. In order to obtain a material with good heat-resistant casting performance, it must meet the requirements of both chemical composition and microstructure. The chemical composition of heat-resistant cast iron mainly includes carbon, silicon, manganese, phosphorus, sulfur, and sometimes a small amount of niobium and vanadium.
Among them, carbon has the most influence on the properties of heat-resistant cast iron. The lower the carbon content, the higher the heat-resistance; but the higher the carbon content, the greater the ability to increase strength. Therefore, by controlling the amount of carbon, the heat-resisting casting performance and the mechanical properties of the material can be form customers required. The usual heat-resistance cast iron is commonly referred to as HT200, HT150, HT250, etc.
For example, HT200 used in common engineering machinery parts not only has high strength and good ductility, but also has the properties of wear resistance and heat-resistance. This kind of heat-resisting cast iron has high performance and low cost and is widely used in many field. Its chemical composition is as follows: C: 2.2-2.6%, Si: 1.4-2%, Mn: 0.4-0.9%, P : 0.1-0.3%, S: 0.1-0.3%, Ni: 0-0.14%, V: 0-0.1%.
On the other hand, HT250 heat-resisting cast iron is widely used in making chain parts, and O-ring sealing rings. This kind of heat-resisting cast iron has higher strength and higher heat-resistance than HT200. Its chemical composition is as follows: C: 2.5-2.9%, Si: 1.7-2.3%, Mn: 0.5-1.1%, P: 0.1-0.3%, S: 0.1-0.5%, Ni: 0-0.15%, V: 0-0.1%.
In summary, heat-resisting cast iron has a wide range of applications due to its good heat-resisting performance and various advantages of mechanical properties. The choice of heat-resisting cast iron depends on the working conditions and performance requirements, and the correct selection of the grade and chemical composition of the heat-resistant cast iron can obtain the best use performance according to the actual working environment and performance requirements.
