VERFAHREN UND VAKUUMOFEN ZUR WAERMEBEHANDLUNG EINER CHARGE

A method and vacuum furnace for heat-treating a charge. Pursuant to the method, after the charge is placed in the receiving vessel, the latter is evacuated and flooded with inert gas. Subsequently, the charge is heated to the maximum permissible operating temperature of the circulation device by heating and gas circulation. Thereafter, the charge is heated to the desired end temperature by static inert gas or under vacuum, and essentially by radiation heat. The vacuum furnace may include a steel vessel which can be closed off, and which contains an inner heating chamber for receiving the charge. A heating device is provided within the heating chamber, and a fan and a gas guiding arrangement are provided for producing a gas circulation through the heating chamber. In the second phase, in which the heating is effected by radiant heat, the heating chamber can be closed off, accompanied by disconnection of the fan. For this purpose, an opening is provided in the wall of the heating chamber. This opening can be closed off by a sliding plug.