On 2018-08-08 14:48:54
vacuum furnace purchasing guide
With the development of the society, people begin to keep improving the requirements of products. As the basic process, more and more attention has been paid to the accuracy requirements of heat treatment. The development of vacuum heat treatment has gradually entered people's sight, and started to have a more intuitive understanding of the importance of vacuum heat treatment. Therefore, the vacuum furnace industry has been fully developed environment, and has also been paid attention by more people. The vacuum heat treatment furnace is safe and reliable, can realize automatic operation, and has little environmental pollution.
It is particularly important to choose the right vacuum furnace when purchasing it, which not only provides convenient conditions for process production, but also saves costs and reduces capital investment for enterprises.
Let's talk with the vacuum furnace manufacturer about the following purchase precautions:
1. To select a vacuum furnace, first of all, according to the chemical composition of the product and the required high heating temperature, the relationship between metal oxide and carbide equilibrium decomposition pressure must be met in terms of the ultimate vacuum degree, and a certain margin must be set, not only the pursuit of high vacuum degree blindly, high vacuum degree will not only cause the volatilization of alloy elements, but also cause the improvement of equipment configuration Resulting in an increase in investment costs.
2. Secondly, according to the cooling form required by heat treatment materials. The cooling methods of vacuum furnace are oil cooling and air cooling. At present, it is mainly air-cooled, which has no pollution and adverse effect on heat-treated parts. After treatment, the surface of parts is clean without cleaning. There is a micro carburizing problem on the oil cooled surface, which has a certain impact on the quality, so it is generally selected gas cooled quenching under the condition of satisfying the cooling speed. The cooling speed of air cooling is mainly affected by the air pressure, flow rate, the form and distribution of air flow and other factors, which should be fully considered in the selection. Generally, the air pressure is high, the flow rate is high, and the cooling speed is fast. In addition, the flow rate of cooling water has a significant impact on the actual cooling. However, some materials can only be quenched by oil cooling, which can not reach the level of heat treatment process under the condition of air cooling. Therefore, when choosing the cooling form, it is more necessary to choose according to the type of material.
3. Selection of heating elements. There are some differences in the form and material of the heating element of the vacuum furnace. Generally, the plate type and the rod type are the main types, and the material is high-strength graphite. But in recent years, the appearance of carbon carbon composite materials has the trend of replacing graphite with its greater technical advantages. Under the same power condition, the thin thickness of carbon carbon composite is less than the heat storage, which is beneficial to improve the cooling rate. However, some materials will react with C at high temperature, which will change its nature. Therefore, in this case, it is impossible to choose the heating element with C as the main material, but the metal material such as stainless steel or molybdenum should be chosen as the heating element.
4. Function. When purchasing the vacuum furnace, the universality of the process should be considered, that is, the range of quenching and tempering temperature should be wide. Especially for the treatment of high alloy steel, the tempering temperature is high and it is very convenient to conduct tempering directly after quenching.
5. Control system. The control system is the core part of the vacuum furnace, to ensure its reliability and perfection. It has monitoring, fault display, recording and other functions.
6. Other sealability and reliability of vacuum system configuration are also important. Equipment modeling should not only strive to be complicated from the form, but also strive to be reliable on the basis of comparison.