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Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

Principle of vacuum heat treatment process

The so-called vacuum heat treatment is a heat treatment method in which the workpiece is heated to the required temperature in a 10^-1~10^-2Pa vacuum medium, and then cooled in different media at different cooling rates.

Vacuum heat treatment is called high-efficiency, energy-saving and pollution-free clean heat treatment by the contemporary heat treatment industry. Vacuum heat-treated parts have a series of advantages such as no oxidation, no decarburization, degassing, degreasing, good surface quality, small deformation, high comprehensive mechanical properties, good reliability (good repeatability, stable life), etc.

Determination of Process Parameters of Vacuum Heat Treatment

1.Vacuum

A few points should be paid attention to when considering the working vacuum degree:

(1) Before 900°C, first draw a high vacuum above 0.1Pa to facilitate degassing.

(2) Heating at 10Pa is equivalent to inert gas with a purity above 1PPM, and generally ferrous metals will not be oxidized.

(3) When filling inert gas, such as filling 133Pa, (50%N₂+50%H₂) nitrogen-hydrogen mixed gas, the effect is better than 10^-2~10^-3Pa vacuum. At this time, the oxygen partial pressure of 66.5Pa is safe.

(4) There is a corresponding relationship between the degree of vacuum and the brightness of the steel surface.

(5) Generally, within the vacuum range of 10^-3~133Pa, the vacuum temperature difference is ±5°C. If the air pressure rises, the temperature uniformity will decrease, so the inflation pressure should be as low as possible.

2.Vacuum quenching heating time

3.Vacuum oil quenching

Several issues to pay attention to when vacuum oil quenching:

① Vacuum oil quenching pressure filling pure N₂ 40kPa~67kPa.

②Quenching oil volume: workpiece: oil weight 1:10~15, the oil pool is 15~20% larger than the sum of oil and workpiece volume.

③ No moisture is allowed in the oil. When it reaches 0.03%, the workpiece becomes dark; when it reaches 0.3%, the cooling rate changes significantly.

④ Preparation of vacuum quenching oil.

⑤The workpiece should be fully degassed before entering the oil.

⑥Use the oil temperature at 40~80℃.

⑦ oil should be stirred. The cooling intensity of stationary oil is 0.25~0.30; the cooling intensity of vigorously stirred oil is 0.8~1.1.

⑧ High temperature instantaneous carburization during vacuum oil quenching.

Vacuum furnace equipment selection: The vacuum heat treatment furnace provided by SIMUWU is an excellent product for processing this kind of process, which has the characteristics of good temperature uniformity and high temperature control accuracy. SIMUWU provides a professional team of engineers who can solve various problems encountered in the production process and is committed to giving customers the most convenient and efficient experience.