is divided into casting of the carbon steel，casting of low alloy steel and casting of special steel.
Casting of the carbon steel: cast alloy steel which has carbon as main alloying element and has little other elements ，carboloy content of mild cast alloy steel is less than 0.2%, carboloy content of medium carbonis 0.2%～0.5%. carboloy content of high-carbon steel casting is more than0.5%，with the increase of carbon content，increase the strength of the casting of the carbon steel，improve the hardness. The casting of the carbon steel has higher strength, plasticity and tenacity，the cost is low，used in parts manufacturing under heavy load of heavy machinery，such as rolling stand ,pedestal of water hydraulic press,etc.
Low cast alloy steel: cast alloy steel has alloying element such as manganese,chromium, copper,etc. Amounts of alloying element is less than 5%generally，has larger impact toughness and can get better mechanical properties by heat treatment.
Casting of special steel: refined alloyfor special requirement，wide varieties，used in the parts which has corrosion or under the working of the 650℃ high temperature conditions.