PRODUCT CATEGORIES

Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

The characteristics and working principle of vacuum heat treatment furnaces

Vacuum heat treatment is a kind of heat treatment process. As long as it involves the field of mechanical manufacturing, heat treatment is a widely used and very important basic process.

Metal materials after vacuum heat treatment can give full play to their performance potential, which is very important for reducing energy consumption, improving the internal quality of products, prolonging the service life of products and improving economic benefits.

As long as the materials of mechanical parts and tools and molds are selected properly, and the proper vacuum heat treatment method is adopted, the service life can be doubled or even increased by ten times, achieving twice the result with half the effort. For example, important mechanical parts or tools such as bearings, connecting rods, gears, and shafts can all use vacuum heat treatment.

The heat treatment process used in the high-temperature vacuum furnace mainly includes the following aspects: high-temperature vacuum annealing, high-temperature vacuum brazing, high-temperature vacuum purification, and high-temperature vacuum sintering.

1.High temperature vacuum annealing

This process is to heat the material above the critical point of the annealing temperature, keep it warm for a certain period of time, and then slowly cool it to 600°C before air cooling.

The purpose of vacuum annealing includes the following aspects:

(1) Reduce the hardness, improve the machining performance such as cutting, and make the material easy to cut;

(2) Improve material plasticity and facilitate cold deformation processing;

(3) Refining grains, eliminating structural defects, and improving performance. The workpieces formed by casting, forging, and welding often have defects such as coarse grains, casting segregation, and banded structures in their structures. Recrystallization once during annealing can eliminate these structural defects and improve performance;

(4) Remove hydrogen to prevent white spots from forming. Large-scale forged and rolled parts cannot be cooled directly below 200°C after pressure processing, and must be cooled by dehydrogenation annealing;

(5) Eliminate stress and stabilize dimensions. Cold stamping or machined parts, after low temperature annealing, eliminate stress, stabilize dimensions, and prevent quenching deformation and cracking;

(6) Prepare tissue for final heat treatment.

2.High temperature vacuum brazing

High-temperature vacuum brazing refers to heating the solder (the welding material connecting the welded parts) to the melting temperature under vacuum conditions, and then using the solidification of the liquid solder and its connection with the base metal (the metal to be welded) A method of realizing the connection between metal parts by diffusion between parts).

3.High temperature vacuum purification

High-temperature vacuum purification refers to the high temperature range (1000 ° C ~ 1500 ° C), under vacuum conditions, by heating the workpiece to be processed, using high temperature and low pressure to volatilize impurities, and vacuum system to pump them out. High-temperature vacuum purification has the advantages of anti-oxidation and good performance consistency of the treated materials.

4.High temperature vacuum sintering

High-temperature vacuum sintering refers to the heating treatment of powder or compact at a temperature lower than the melting point of the main component under vacuum conditions, and the strength is improved by the connection between particles.

Vacuum sintering has the following advantages:

(1) Vacuum has the function of protecting the atmosphere;

(2) Vacuum has a reducing effect;

(3) Vacuum has a good degassing effect;

(4) The vacuum atmosphere is easy to promote the wetting of the liquid relative to the solid phase;

(5) Vacuum has the effect of activating sintering;

(6) The use of vacuum sintering can avoid the chemical reaction between the protective atmosphere and the sintered body;

(7) Vacuum has the function of purifying materials;

(8) Vacuum sintering can improve the quality of sintered body.

This series of advantages has made the development of high-temperature vacuum equipment and processes more and more important, and the application fields of equipment are becoming wider and wider.

The improvement of the quality, control technology and reliability of vacuum heat treatment equipment can ensure the quality of heat treatment products, thereby greatly improving the performance of vacuum heat treatment products. The important indicators to measure the performance of vacuum heat treatment equipment are the size of the effective working area in the equipment and whether the temperature in the area is uniform.

As a representative high-temperature vacuum furnace for vacuum heat treatment equipment, the overall internal temperature is relatively high during the working process, and the heat energy transfer is mainly based on radiation. There is a gradient in the temperature distribution of each point in the furnace space. The thermal insulation effect varies with each other, so reasonable selection of heating elements and thermal insulation materials, effective arrangement of them, and study of thermal field distribution can make the equipment function better.