Verfahren und Vorrichtung zur Wärmebehandlung von Teilen

摘要

The invention relates to a method and a device for thermal treatment of parts, which are exposed to a protected furnace gas atmosphere generated in situ in a processing chamber of a furnace in order to substantially preserve the surface properties of said parts. The inventive method comprises the following steps: heating the furnace at a temperature above 600 DEG C and injecting or introducing nitrogen gas with up to 3 vol. % oxygen and a reducing gas into the processing chamber. In order to adapt the amount of hydrocarbons to the oxygen content of the gaseous atmosphere in the processing chamber of the furnace, the invention provides that the oxygen activity of the protective gas generated in the processing chamber (10) of the furnace (14) is measured, an actual value signal is generated on the basis of the measured value of oxygen activity, the actual value signal is fed to a control unit (15) in which a set value for the oxygen activity is stored, a set value signal is formed on the basis of the set value, which is then compared with the actual value signal and the control unit (15) modifies the supply of reducing gas in the event of variations between the actual value and the set value signal until the actual value signal matches the set value signal.