Water-based quench, usually built on polyalkylene glycol (PAG), whose cooling rate is set by concentration (often 5 to 25 percent), bath temperature and agitation. The polymer comes out of solution on hot steel as a film that slows cooling, then redissolves as the part cools. Polymers avoid oil fires and smoke, but concentration has to be checked by refractometer every shift, since drag-out and contamination shift the quench rate.
Polymer quenchant is reading 14 percent on the refractometer, spec is 12, add water before the next induction lot.
Also heard as
- polymer quench
- PAG quenchant
- glycol quench
Related terms
Quenchant
The liquid or gas used to quench parts, chosen for its cooling speed and the distortion it produces.
Quench severity
How fast a quenchant pulls heat out of steel, usually rated by the Grossmann H value.
Agitation
Forced movement of quenchant around parts by pumps, propellers or nozzles to speed up and even out cooling.
Induction hardening
Heating only the surface of a steel part with an alternating magnetic field, then quenching for a hard case.