On 2018-08-08 14:48:54
vacuum heat treatment furnace advantages and technology
1)vacuum heat treatment advantages :
Vacuum heat treatment is a non oxidation heat treatment technology which is widely used in parallel with controllable atmosphere, and it is also one of the main signs of the advanced degree of heat treatment production technology. Vacuum heat treatment can not only realize no oxidation and no decarburization of steel parts, but also realize no pollution and less distortion of workpieces, so it belongs to clean and precision production technology. At present, it has become an irreplaceable advanced technology in the production of tooling.
2) Heat treatment process of high temperature sintering furnace:
Small distortion of workpiece is a very important advantage of vacuum heat treatment. According to the experience at home and abroad, the distortion of vacuum heat treatment is only one third of that of salt bath quenching. It is of great significance to study the vacuum heating method and the distortion law of various materials and parts with different complexity under various cooling conditions, and simulate them with computer. The uniformity of air flow during vacuum heating, atmospheric pressure or high pressure air cooling has a great influence on the hardening effect and quality dispersion of parts. It is of great significance to study the air circulation law in the furnace by means of computer simulation for improving the furnace structure.
Vacuum carburizing is the most possible way to realize high temperature carburizing. However, long-time heating at high temperature will make the austenite grain size of most kinds of steel grow very large. It is necessary to study the influence of high-temperature carburizing and reheating quenching on the properties of materials and workpieces for the optimization of vacuum carburizing, cooling, heating quenching process and equipment. In recent years, there is a trend of research and development of combustion vacuum furnace using gas fuel in the world. It is too difficult to use gas fuel to heat in vacuum furnace. Although there is a view of saving energy, it is not necessarily an important development direction.
3) Ultra high vacuum high temperature sintering furnace vacuum heat treatment furnace:
Modern vacuum heat treatment furnace is a cold wall furnace which can heat components in vacuum and then quench them in oil or in atmospheric pressure and pressure gas. Research and development of this type of equipment is a comprehensive, interdisciplinary work involving many scientific and technological fields. The application prospect of vacuum heat treatment of die material is very big. Most die steels are heated in vacuum and then cooled and quenched in gas. In order to obtain satisfactory mechanical properties on the surface and inside of the workpiece, it is necessary to use the technology of vacuum high pressure gas quenching.
At present, the pressure of vacuum gas quenching in the world has increased from 0.2MPa, 0.6MPa to 1-2mpa or even 3Mpa. Therefore, it is an important development trend to gradually increase the cooling gas pressure of high pressure gas quenching vacuum furnace. In addition to high-pressure gas quenching, the speed of convective heating after vacuum pumping and filling with high-pressure inert gas can be more than twice that of traditional vacuum radiation heating, so obviously improving the heating efficiency is one of the important directions of vacuum heating technology. The multi-functional development is also one of the trends of vacuum furnace. One of the typical examples is the semi continuous vacuum heat treatment equipment, in which oil quenching is carried out in the front chamber, atmospheric pressure or high pressure gas quenching is carried out in the back chamber, and vacuum heating or plasma carburizing is carried out in the middle heating chamber.
At present, the domestic market of high temperature vacuum furnace has reflected the demand of this furnace type. Various kinds of continuous vacuum carburizing, high pressure, air cooling, quenching and tempering production lines which can meet mass production have been produced one after another. It can be expected that in the near future, it will lead to a major change in the heat treatment of automobile parts. According to the characteristics of high temperature carburizing easily realized by vacuum heating, the development of high temperature (1000 ℃ ~ 1050 ℃) carburizing, slow cooling, reheating, quenching in oil, cleaning and tempering production lines should be put on the agenda as soon as possible