Vacuum heat treatment is a comprehensive technology combining two specialties of vacuum technology and heat treatment, which means that all and part of the heat treatment process is carried out in a vacuum state. Vacuum heat treatment can realize almost all heat treatment processes, such as quenching, annealing, tempering, carburizing, nitriding, and gas quenching, oil quenching, water quenching, etc. in the quenching process. Compared with traditional heat treatment, it has the following advantages.

1. No oxidation, no decarburization, and no carbon increase, which has a good protective effect on the inside and surface of the workpiece. Oxidation tarnishes the surface of the metal, increases the surface roughness, and reduces the precision, and the oxide skin on the steel surface is often the root cause of quenching soft spots and quenching cracks. Oxidation reduces the strength of the steel and other mechanical properties. Decarburization refers to the phenomenon that the surface carbon content of steel decreases when it is heated. Under normal circumstances, the oxidation and decarburization of steel are carried out at the same time. Due to the oxidation of the decarburized layer, the reduction of the carbon content will significantly reduce the quenching hardness, wear resistance, and fatigue properties of the steel. The decarburization of high-speed steel will reduce the red hardness. In vacuum heat treatment, since the metal is heated under a certain degree of vacuum, the workpiece avoids contact with oxygen, the workpiece is not oxidized, and there is no decarburization, so a bright surface and better heat treatment quality can be obtained. If the reduction reaction occurs, the phenomenon of carbon increase will not occur.

2. Improve the overall mechanical properties, degas and promote the purification of metal surfaces. The vacuum has obvious degassing effect on liquid metal, and also has a good removal effect on dissolved gas in solid metal. The most harmful gas in metals is hydrogen. When vacuum heating is used, hydrogen in metals and alloys can be rapidly reduced to a low level, and hydrogen embrittlement is eliminated, thereby improving the plasticity, toughness and fatigue strength of the material, and improving the overall mechanical properties of the workpiece. When metals and alloys are heated in a vacuum, if the vacuum degree is lower than the decomposition pressure of the corresponding oxides, the oxides will decompose, and the free oxygen formed is immediately discharged from the vacuum chamber, so that the surface quality of the metal is further improved, and even the The surface reaches an activated state and plays a purifying role.

3. The workpiece deformation is small. Generally speaking, the workpiece to be treated is heated by thermal radiation in the furnace, the temperature difference between the inside and outside is small, and the thermal stress is small, which determines that the deformation of the parts treated by the vacuum heat treatment process is small. At the same time, heating and quenching under vacuum are completed automatically. , to avoid the handling of the workpiece in the air in the hot state, reduce the artificial processing deformation, and improve the product qualification rate.

4. It can reduce the volatility of gold-containing elements in the workpiece. Vacuum heat treatment can be heated and vacuum quenched in a controlled atmosphere, thereby reducing the volatility of gold-containing elements in the workpiece and ensuring the heat treatment quality of the workpiece.

5. The vacuum heat treatment furnace has high thermal efficiency, can achieve rapid heating and cooling, and has good stability and repeatability. The working environment is good, the operation is safe, and there is no pollution and public nuisance.