TMP · Tempering
After the quench, steel is hard and brittle. Tempering reheats it to a set temperature to relieve quench stress and bring hardness to the value on the drawing.
- Furnace
- TFC-1, 2, 3
Source · STEP process inspection records
What it does
The step that makes a hardened part usable.
Every part we harden is tempered.
- Low temper keeps case hardness on carburised and carbonitrided parts while relieving stress.
- Higher temper trades hardness for toughness on through-hardened parts.
- Time matters: untempered martensite can crack. We start within 4 h of the quench or snap temper to hold the lot.
Typical cycle
The cycle, as we run it.
TMP
Tempering
- Temper150–190 °C
- Soak90 ± 10 min
- Coolair
- FurnaceTFC-1, 2, 3
- Start≤ 4 h after quench
STEP typical parameters from process inspection records. Times illustrative; actual cycle per part specification.
Questions
Asked about tempering.
Can you temper parts hardened somewhere else?
Yes, if the quench time is known. Without it we cannot pass the quench-to-temper check, and we will tell you before we take the lot.
What is a snap temper?
A short, low temper, 140 ± 10 °C for 60 min, that holds a freshly quenched lot safely until the full temper can start.
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