What are the advantages and disadvantages of internal heating vacuum heat treatment furnaces
Compared with the external heating type vacuum heat treatment furnace, the internal heating type vacuum heat treatment furnace has more complicated structure and control system, higher precision of manufacturing and installation, more difficult debugging and more expensive cost. However, the internally heated vacuum heat treatment furnace has low inertia, high thermal efficiency, can achieve rapid heating and rapid cooling, and has a high operating temperature. At present, the internally heated vacuum furnace of 2200～2500℃ has been successfully developed and used for production. At the same time, the internally heated vacuum furnace can be large It is convenient for continuous operation, high degree of automation and high production efficiency. In the past ten years, the internal heating vacuum furnace has developed rapidly and has become the mainstream furnace type of the current vacuum heat treatment furnace.
The advantages of internal heating vacuum furnace mainly have the following seven points:
1. Large-scale high-temperature furnaces can be manufactured without being restricted by the furnace pot;
2. Fast heating and cooling speed, high production efficiency;
3. Because heat-resistant furnace is not used, the temperature range is wide, and the maximum heating temperature can reach 2200℃ or higher;
4. It is easy to realize the automation of the whole process, there is no pollution in the work, the environment is good, and the operation is safe;
5. The furnace has small thermal inertia, short heating and cooling process cycles, high thermal efficiency and high production efficiency;
6. The furnace temperature has good uniformity, up to ±5℃, the workpiece is heated evenly, the deformation is small, and the product quality is good;
7. No protective atmosphere is needed during heating. Unless the gas is introduced to prevent volatilization of metal or to increase the heating speed and furnace temperature uniformity in the low temperature zone, N₂, Ar or Ne gas is generally used for filling gas.
The disadvantages of internal heating vacuum furnaces are as follows:
1. The furnace structure is complex, the furnace cost is high, and the electrical insulation requirements are high;
2. Compared with the external heating vacuum furnace, the furnace has a large internal volume, and a large amount of gas is adsorbed on the surface of various components, which requires a high-power extraction system;
3. Considering vacuum discharge and electrical insulation, low-voltage and high-current power supply requires supporting systems.