Quenching is the rapid cooling of metals.Originally posted by cajungeo
In heat treating it is called quenching. It is a common procedure to heat brass cases with a torch, then emerse in water, to soften the metal.
In the heat treating of steels rapid cooling causing hardening.
However in non-ferris materials like copper, lead, brass etc. quenching causes annealing (softening) to occure, while slow cooling causes them to harden. Just the oppisite of steel.