Cast steel used for pouring casting of steel, is a kind of casting alloy. The cast steel is mainly used in the manufacture of some complicated shape, difficult to forging or cutting shape and required high strength and plastic parts. Cast steel can be according to the chemical composition is divided into: carbon cast steel and alloy steel casting. Carbon steel casting according to carbon content is divided into: C 0.20% or less for low carbon cast steel; C0.2 ~ 0.5% for medium carbon steel; C 0.5% or higher for high carbon steel. Cast steel according to the content of alloy elements are divided into: low alloy steel (alloy elements in less than 8% of the total) and high alloy steel (over 8% in the total general alloy elements). Cast steel can be divided into: according to the use structure of the cast steel, wear-resistant cast steel, stainless steel casting, heat resistant cast steel, tool steel casting, etc. Cast steel according to the organization are divided into: pearlite cast steel, cast steel, ferrite martensitic cast steel and austenitic cast steel and so on. Cast steel is a casting, forging forming workpiece can improve the organization structure, mechanical performance is good,