As the maraging steel is strengthened by the precipitation of intermetallic compounds generated by some alloy elements during aging rather than by the supersaturated solution of carbon or carbide precipitation, the carbon in the steel, like sulfur and phosphorus, is a harmful impurity element. It is required that the lower the carbon content is, the better. Generally, it should not exceed 0.03% (for important purposes, it should be less than 0.01%). The main alloying elements in steel are nickel, cobalt, molybdenum, titanium,
Chromium and manganese can be used to partially replace nickel and cobalt in maraging steels, and tungsten can also be used to replace molybdenum or vanadium can be used to replace cobalt in recently developed cobalt free steels. Silicon is an impurity element, and its content shall not exceed 0.1%. Aluminum I is generally added as deoxidizer in steelmaking, and its residual amount ranges from 0.05% to 0.2%. In addition, trace elements such as boron, zirconium, calcium, magnesium and rare earth elements can be used to improve some properties of steel.
