Any medium used to pull heat out during quenching. The rough order from fastest to slowest is brine, water, polymer solutions, fast oils, conventional oils, hot marquench oils and salts, pressurized gas and still air. Each needs monitoring: oil for water content, oxidation and cooling curve, polymer for concentration by refractometer, salt for contamination. A tired quenchant shows up as soft spots and widening hardness scatter.
Send a sample of the quenchant out for a cooling curve, I think tank two is drifting slow.
As little as 0.1 percent water in quench oil can cause soft spots, cracking and dangerous foaming, so a leaking oil cooler is an emergency.
Also heard as
- quench medium
- quench media
Related terms
Quench
To cool hot metal rapidly in a liquid or gas so that it hardens, or the act of doing so.
Polymer quenchant
A water solution of polymer that quenches at a speed between water and oil, tuned by its concentration.
Hot oil
Shop name for quench oil run at about 120 to 230 °C for marquenching and low-distortion quenching.
Quench severity
How fast a quenchant pulls heat out of steel, usually rated by the Grossmann H value.
Vapor blanket
The film of vapor that wraps red-hot steel at the start of a liquid quench and slows its cooling.