Vacuum heat treatment technology: principles, characteristics and applications

In the field of modern material processing, heat treatment technology plays a vital role in improving the performance of metal materials. As a new type of heat treatment method, vacuum heat treatment technology organically combines vacuum technology with traditional heat treatment technology, showing unique advantages and broad application prospects.

Process principle of vacuum heat treatment technology
(I) Phase change characteristics of metals under vacuum
In a vacuum environment with a pressure difference of only 0.1MPa from atmospheric pressure, the thermodynamics and kinetics of solid phase change of metals remain basically stable. This enables us to fully draw on the principles and organizational transformation data of solid phase change under normal pressure when formulating vacuum heat treatment process regulations, providing a solid theoretical basis for process design.

(II) Vacuum degassing and performance improvement
Vacuum degassing is of key significance in the vacuum heat treatment process. By removing gas impurities in metal materials, the physical and mechanical properties of metal materials can be effectively improved, making the internal structure of the material more uniform and dense, thereby enhancing its comprehensive performance.
(III) Evaporation of metal surface elements and surface purification
When heated in a vacuum state, the elements on the surface of metal workpieces evaporate. This process helps to achieve oxidation-free heating of the metal. The required vacuum degree can ensure the surface purification effect, reduce the occurrence of oxidation and decarburization, and ultimately achieve the purpose of surface bright purification, meeting the application scenarios with high requirements for metal surface quality.

Characteristics of vacuum heat treatment processing technology

(I) Advantages of vacuum heat treatment processing
1. No oxidation, no decarburization and no pollution
Vacuum heat treatment technology can effectively avoid the oxidation and decarburization problems of steel parts during the processing process, ensuring the stability of the chemical composition and surface quality of the workpiece. At the same time, because it is carried out in a vacuum environment, it reduces the generation of pollutants such as waste gas and waste slag, which conforms to the concept of modern green manufacturing and is a clean production technology.
2. Less distortion of workpieces
Compared with traditional salt bath heating and quenching, the distortion of workpieces after vacuum heat treatment is significantly reduced, which is only one-third of that of salt bath heating and quenching. This is of great significance for improving the dimensional accuracy and shape accuracy of workpieces, especially for heat treatment of parts such as molds with complex shapes and high dimensional accuracy requirements.
In-depth research on the distortion laws of various materials and parts of different complexity under vacuum heating methods and different cooling conditions, and analysis and prediction with the help of computer simulation technology, is crucial for the promotion of vacuum heat treatment technology. In the process of vacuum heating, atmospheric pressure or high pressure air cooling quenching, the uniformity of air flow has a great influence on the hardening effect and quality dispersion of parts. By computer simulation of the airflow circulation law in the furnace, a scientific basis can be provided for improving the furnace structure, further optimizing the vacuum heat treatment process, and improving the stability and consistency of product quality.

(II) Application of vacuum heat treatment furnace
Modern vacuum heat treatment furnaces usually refer to vacuum furnaces that can achieve vacuum heating of components, followed by quenching in oil or quenching in normal pressure and pressurized gas. The research and development of this type of furnace involves multiple disciplines and is highly comprehensive. It must not only meet the requirements of the vacuum environment, but also ensure the precise control of the heating, cooling and other process processes, as well as the reliability and stability of the equipment.

Vacuum Heat Treatment Furnace