An alloy is a substance consisting of two or more chemical elements with one of them being a metal thus resulting in desired metallic properties.Steel is an alloy of Iron and carbon.

Functions of main Alloying elements

Carbon(C):
Directly influences the hardness and strength of the steel, decreases toughness.

Chromiun(Cr):
Improves Hardenability, high temperature strength, wear resisitance and even corrosion resistance(Cr>14%).

Cobalt(Co):
Improves retention of hardness at high temperatures.

Molybdenum(Mo):
Increases yield point and strength. Improves Hardenability and wear resistance. Manganese Lowers effects of Iron sulphides, increases hardenability, wear resistance.

Nickel(Ni):
Increases toughness at lower temperatures, slows the corrosion process.

Tungston(W):
Improves toughness, grainstructure, high temperature strength, wear resistance, etc.

Vanadium(V):
Increases wear resistance, high temperature strength, retention of hardness etc.

Silicon(Si): It is of importance that certain elements are as low as possible. Elements like Hydrogen, Oxygen, Nitrogen, Phosphorous, Sulphur create defects inside & also reduce the mechanical properties of steels.

It is of importance that certain elements are as low as possible.Elements like Hydrogen,Oxygen,Nitrogen,Phosphorous,sulphur create defects inside also reduce the mechanical properties of steels.