Hardening ability of metals

Question

What is meant by the term hardening ability of metals?

Answer 1

It is the capability of the metal to become solid and unbreakable (and inevitably brittle) under the given cooling rate. Thus, the higher the harden capability of the alloy, the lower the cooling rate needed to harden the metal. We have more heard about the harden capability in steels rather than other alloys. This is since in steels, there are dissimilar phases that can appear subject to applied cooling rate below critical temperature (or eutectoid temperature) as well as alloying elements present in that grade of the steel. Most of alloying elements in steel perk up it’s harden capability by reducing the critical cooling rate needed to obtain the hardest probable phase i.e. marten site.