The properties of steel can be improved in terms of fatigue, weldability, hardness, wear and corrosion resistance, ductility, and tensile strength by either alloy addition or heat treatment processes.

Alloy steels are designated by AISI four-digit numbers. They contain different kinds of steels having compositions which exceed the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon ...