Talking about the heat treatment skills of vacuum furnace from Sanqian's blog

Do you know vacuum furnaces? Vacuum furnaces play an irreplaceable role in mold production and are mainly used for ceramic firing, vacuum smelting, degassing of electric vacuum parts, annealing, brazing of metal parts, and ceramic-metal sealing. The vacuum heat treatment of the vacuum furnaces can realize almost all heat treatment processes, such as quenching, annealing, tempering, carburizing, and nitriding. In the quenching process, gas quenching, oil quenching, nitrate quenching, water quenching, etc. Brazing, sintering, surface treatment, etc. The vacuum furnace has high thermal efficiency, can achieve rapid heating and cooling, can achieve no oxidation, no decarburization, no carburization, can remove phosphorus chips on the surface of the workpiece, and has the functions of degreasing and degassing, so as to achieve the effect of a bright and clean surface.

Generally speaking, the workpiece to be processed is heated slowly in the furnace, the internal heat temperature difference is small, the thermal stress is small, and the deformation is small. The product qualification rate is high. It can reduce the cost and has the effect of degassing, thereby improving the mechanical performance and service life of the work. The working environment is good, the operation is safe, and there is no pollution and public nuisance. The workpiece to be treated has no danger of hydrogen embrittlement, the surface hydrogen embrittlement of titanium and refractory metal shells is prevented, and the stability and repeatability of the vacuum heat treatment process are good. With this series of advantages, the development of vacuum heat treatment equipment and processes has been paid more and more attention and applied more and more widely.

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. my country divides vacuums into low, medium, high, and ultra-high vacuums.

Vacuum furnaces and intermediate frequency electric furnaces have good development prospects in the field of thermal processing, which are used for induction heating of diathermy, rolling, forging, pipe bending, heat treatment (quenching), welding, and other processes. So what are the heat treatment skills of vacuum furnaces and intermediate frequency electric furnaces?

1. When treating titanium alloys in a vacuum furnace, nitrogen should not be used as a cooling gas, because titanium and nitrogen react at high temperatures to form golden titanium nitride.

2. The movable connection parts of the vacuum furnaces are all sealed and connected by O-shaped rubber rings, and this part is cooled by water.

3. When the workpiece is quenched in a vacuum state, vacuum quenching oil should be used, which has a low saturated vapor pressure.

4. The maintenance of the vacuum furnaces should be in the state of vacuum or pure nitrogen, to avoid inhalation and moisture absorption when not in use.

5. The pressure rise rate of the domestic vacuum furnaces should be no more than 1.33Pa/h, and the standard of some foreign enterprises is 0.67Pa/h.

6. The vacuum heating is mainly based on radiation, and the workpiece should be kept apart in the furnace.

7. During the heating process, the workpiece and the materials in the furnace will be out of gas, which will reduce the vacuum degree.

8. The heating temperature of vacuum tempering, vacuum annealing, vacuum solution treatment, and vacuum aging is generally the same as that of conventional treatment.

9. The vacuum tempering furnace should have a quick cooling device. The pressure of cooling water should be greater than 0.2Mpa, and the flow should be adjustable.

10. Cooling gas: steel generally uses 99.995% nitrogen, high-temperature alloys use 99.999% nitrogen or argon, and titanium alloys use 99.995% argon.

11. Heating up: After placing the workpiece, it is generally pre-pumped to 6.67Pa before heating up.

Changzhou Sanqian Technology Co., Ltd. sells Vacuum brazing of liquid-cooled plates, if you need it, welcome to consult us!