Chemical element that in rolled steels strengthens the ferrite and increases toughness. It also increases tensile strength and yield strength.
It avoids the growth of grain in the thermal treatments, reason why it maintains the toughness of the steel to high temperatures. Superalloys or nickel based alloys are used in engines and components that work at high temperatures for this reason.
It is broadly used, being used in carbon steels to increase its hardenability and hardness, in alloy case-hardening steels because of the great hardenability it confers to the case-hardened layer, and in stainless steels, especially in the austenitic ones, where as a gamma element provides them with an austenitic structure at room temperature, with the following properties: ductility, toughness and resistance to corrosion.