Floor term for a high-flash-point quench oil held hot, usually 120 to 230 °C (250 to 450 °F), for marquenching gears and bearing parts. The smaller temperature gap between part and bath, plus thinner oil, cuts distortion. The oil needs a flash point well above its working temperature and must stay dry, because water hitting hot oil can foam over violently.
Ring gears go in the hot oil at 300, the cold tank is for shafts.
Also heard as
- marquench oil
- martemp oil
- hot quench
Related terms
Marquenching
Quenching steel into hot oil or salt just above Ms, holding to even out temperature, then air cooling.
Quenchant
The liquid or gas used to quench parts, chosen for its cooling speed and the distortion it produces.
Distortion
Unwanted change in shape or size of a part during heat treatment, such as bowing, warping or ovality.
Quench
To cool hot metal rapidly in a liquid or gas so that it hardens, or the act of doing so.