General term for heating to a set temperature, holding and cooling slowly to reach a soft, stable structure. Full annealing of steel austenitizes above Ac3 and furnace-cools slowly through the critical range, giving coarse pearlite and ferrite. Variants include process annealing below Ac1 for cold-worked low-carbon steel, spheroidize annealing for high-carbon steel, and solution annealing for stainless and nickel alloys. For copper and aluminum, annealing mainly means recrystallizing cold-worked metal.
Bar came in too hard to saw, send it out for a full anneal before anybody machines it.
Also heard as
- anneal
- full anneal
- process anneal
Do not mix it up with
- Normalizing: Annealing cools slowly in the furnace for maximum softness, while normalizing cools in air for a finer, stronger structure.
Related terms
Spheroidizing
Long holds near the lower critical temperature that turn carbides into small round particles.
Normalizing
Heating steel above its upper critical temperature and cooling it in still air to refine and even out grain.
Dead soft
Fully annealed to the lowest hardness the metal can reach, with no work hardening left in it.
Stress relieving
Heating a part below its transformation range to relax residual stress from welding, machining or forming.