The microstructure, mechanical properties and wear resistance of medium carbon alloy steel have been investigated by means of the optical microscope, the scanning electron microscope, the tensile test, the hardness test, the impact test, the fracture test and the wear test. The results show that the bainite and retained austenite were obtained under the condition of air hardening in the carbon steel containing 0·30-0·45 wt-%C, by increasing the concentrations of silicon and manganese, adding proper boron, nickel, vanadium, titanium and rare earth, and appending the pretreatment of ...
