VACUUM TEMPERING

Vacuum tempering is being used for tempering high-speed steels and alloy steels to produce a scale-free finish. A vacuum tempering furnace is very versatile and can be used for bright tempering, aging and annealing. Other less common applications include degreasing, resin bake-off and preferential oxide treatment of low carbon steels.

Vacuum Tempering is almost always required after hardening (both in an atmosphere furnace as well as in vacuum), to reduce the hardness (and brittleness) of the treated material to a desirable level.

Generally it is not necessary to use vacuum tempering after vacuum hardening, i.e., conventional tempering is most of the time used. Vacuum tempering may be used on high value products, when totally clean surface appearance is required. The expression "vacuum tempering" is used here to differentiate the process from.