vacuum atmosphere furnace working principle

Vacuum atmosphere furnace is a new heat treatment technology combining vacuum technology and heat treatment technology. The vacuum environment of vacuum heat treatment refers to the atmosphere environment lower than one atmospheric pressure, including low vacuum, medium vacuum, high vacuum and ultra-high vacuum. Vacuum heat treatment actually belongs to atmosphere controlled heat treatment.

Vacuum heat treatment means that all and part of the heat treatment process are carried out in vacuum state. Compared with conventional heat treatment, vacuum heat treatment can realize no oxidation, no decarburization, no carburization, and can remove the phosphorus chips on the surface of the workpiece, and has the function of degreasing and degassing, so as to achieve the effect of surface bright purification.

In order to improve the heating speed and furnace temperature uniformity in the vacuum sintering process, a proper amount of gas (inert gas or hydrogen) can be introduced in the initial stage of sintering. The cooling rate of vacuum sintering can also be increased by using the method of gas cooling. In order to prevent the formant from polluting the vacuum system, the briquette should be pre fired before vacuum sintering to remove the formant.

There are many kinds of atmosphere furnaces, which can be classified according to the atmosphere in the furnace body. The characteristics of atmosphere furnaces are that under a certain temperature, certain composition of artificial preparation atmosphere is put into the furnace to achieve some purpose of heat treatment, such as gas carburizing, carbonitriding and bright quenching, annealing, normalizing, etc. In order to control the atmosphere in the furnace and maintain the pressure in the furnace, the working space in the furnace shall always be isolated from the outside air to avoid air leakage and inhalation as much as possible. Therefore, sealing devices shall be adopted for the furnace shell, masonry, furnace door and all external connecting parts such as fan, thermocouple, radiation tube, pusher and puller.