Linked from
The 15 pages that link to Quenching, each with the reason it gives.
SteelRelated: Quenching steel can form hard martensite from austenite.
TemperingRelated: Quenching creates the hard, brittle structure that tempering then modifies.
BlacksmithingRelated: Blacksmiths use it to cool workpieces and, in suitable steels, alter hardness.
MartensiteRelated: Quenching steel can suppress diffusional transformations and produce martensite.
Chain terminationRelated: A quencher can consume the active center and terminate polymer growth.
BlacksmithRelated: The cooling method can harden steel after a blacksmith shapes and heats it.
Spring steelRelated: Quenching hardens spring steel before tempering adjusts its brittleness.