Vacuum Heat Treating

Normally when the word vacuum is used it refers to any absolute pressure below that of normal atmospheric pressure. Atmospheric pressure is defined as 14.6 psia or 760 torr, any pressure less than this is considered a vacuum. In a vacuum furnace, the heat-treating process takes place inside a vessel that is airtight. This allows a vacuum to be drawn inside the vessel. The entire heat-treating process can take place under vacuum or precisely controlled atmospheres can be introduced. Heat treating under vacuum can: prevent surface reactions, such as oxidation or decarburization; remove surface contaminants such as oxide films and residual traces of lubricants; add a substance to the surface layers of the work; remove dissolved contaminating substances from metals by means of degassing.