Aging induced by rapid cooling; embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel. It is the side effect of differences in the solid solubility of carbon in ferrite at different temperatures.

Quench-age embrittlement is often caused by too-rapid cooling of the steel from temperatures slightly below the austenite formation temperature; it can be usually be minimized by quenching from a lower temperature.

The process of rapidly cooling metal parts such as bearing races down from their heat treat furnace temperature. There are a number of quench opetions, including water tank, oil tank, polymer solution, and salt.