One of the most widely used alloying elements in
steel. In amounts 0.50% to 5.00% its use in alloy
steels increases the toughness and tensile strength
without detrimental effect on the ductility. Nickel
also increases the hardenability, thus permitting the
steel to be oil-hardened instead of water quenched.
In larger quantities, 8.00% and upwards, nickel is
the constituent, together with chromium, of many
corrosion resistant and stainless austenitic steels.