Characteristics of vacuum heat treatment furnace　　

1. Tight vacuum seal: As we all know, vacuum heat treatment of parts is carried out in a closed vacuum furnace. Therefore, obtaining the original leakage rate of the furnace and ensuring the vacuum degree of the vacuum furnace is very important to ensure the quality of vacuum heat treatment of parts. Therefore, a key problem of the vacuum heat treatment furnace is to have a reliable vacuum seal structure. In order to ensure the vacuum performance of the vacuum furnace, a basic principle must be followed in the structure design of the vacuum heat treatment furnace, that is, the furnace body must be airtight. Welding, and at the same time, as little or no holes are opened on the furnace body as possible, and dynamic sealing structure is used less or avoided to minimize the chance of vacuum leakage. Parts and accessories installed on the vacuum furnace body, such as water-cooled electrodes and thermocouples, are exported The stomach must also be designed with a sealed structure.

2. Most heating and heat insulation materials can only be used in a vacuum state: The heating and heat insulation linings of the vacuum heat treatment furnace work under vacuum and high temperature, so this material has high temperature resistance and low vapor pressure. The radiation effect is good, the thermal conductivity is small, and the oxidation performance is not high. Therefore, the vacuum heat treatment furnace widely uses tungsten, platinum and graphite as heating and heat insulation materials. This material is extremely easy to track in the atmosphere. Therefore, conventional heat treatment furnaces cannot use these heating and heat insulating materials.

3. Use low voltage and high current: In the vacuum vessel, the energized conductor in the vacuum vessel will produce glow discharge under higher voltage. In the vacuum heat treatment furnace, severe arc discharge will be generated, which will burn the heating element and insulation. The heating layer, etc., cause major accidents and reports of loss. Therefore, the working voltage of the electric heating element of the vacuum heat treatment furnace is generally not more than 80-100 volts. At the same time, effective measures must be taken in the structure design of the electric heating element, such as the distance between the electrodes. Too small and narrow to prevent glow discharge or arc discharge from occurring.

4. High degree of automation: The high degree of automation of the vacuum heat treatment furnace is due to the heating and cooling of metal workpieces, which require more than a dozen or even dozens of actions to complete, and these actions are in the vacuum heat treatment furnace. At the same time, if there is such an action, such as after the heating and holding is finished, the quenching process of the workpiece must be completed within 15 seconds. Many tasks are completed in such a rapid condition, which is very easy to cause operation The tension of the personnel constitutes a misoperation. Therefore, only a high degree of self-function can accurately and timely coordinate the functions according to the procedures.

 5. Water cooling device, vacuum heat treatment furnace shell, furnace cover, electric heating element, separate disposal (water cooling electrode), intermediate vacuum insulation door and other components, all work under vacuum and heating, and work under such extremely unfavorable conditions , It is necessary to ensure that the structure of each component is not deformed or damaged, and the vacuum seal ring is not overheated or burned. Therefore, each component should be equipped with a water cooling device according to different conditions to ensure that the vacuum heat treatment furnace can operate normally and have a sufficient service life.