Cast steel is used to pour investment castings, which is one type of alloys. Currently Cast steel is mainly used in the manufacture parts of some complicated shape, difficult to forging or machining shape and required high strength and plasticity.
Cast steel according to the chemical composition is divided into: carbon steel casting and alloy steel casting. Carbon steel casting according to carbon content is divided into: C≤ 0.20% for low carbon steel; C：0.2 ~ 0.5% for medium carbon steel; C ≥0.5% for high carbon steel.
Cast steel according to the content of alloy elements are divided into:low alloy steel (total alloy elements in less than 8%) and high alloy steel (over 8% in the total general alloy elements).
Cast steel according to the usage can be divided into:structural cast steel,wear-resistant cast steel,stainless steel cast steel,heat resistant cast steel,tool cast steel, etc.
Cast steel according to the organization are divided into:pearlite cast steel,ferritic cast steel,martensitic cast steel,austenitic cast steel and so on.
Heat treatment of cast steel:
1.Heat treatment of cast steel consists of three stages: heating, heat preservation and cooling.The determination of its parameters are based on ensuring quality and cost savings of investment castings.
2.Cast steel main heat treatment ways according to different heating and cooling conditions are:annealing,normalizing,homogenization treatment, quenching,tempering,solution treatment,precipitation hardening and eliminating hydrogan treatment.
3.Annealing is the heat treatment process of heating the steel above a certain temperature, heat preservation time and cooling.
4.Carbon steel organization after annealing: hypoeutectoid cast steel for ferrite and pearlite, eutectoid steel casting for pearlite, hypereutectoid steel casting of pearlite and carbide. Apply to all grades of cast steel.