Low-temperature annealing processes (stress relieving, rekristalization and soft annealing) are usually performed in the air atmosphere because the protection of the steel surface against oxidation or decarburization is not necessary. If needed protecting the surface, protective inert gas atmosphere are used, like for tempering. Heating and cooling rates are limited to prevent thermal stresses in annealed steel parts. Different types of furnaces are used for annealing of steel parts.

Bell type furnaces

Bell type furnace for recristalization annealingBell type furnace for stress relieving on two workbases