Process, Features and Uses of Vacuum Heat Treatment Furnace

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Preface: The scope of application of vacuum furnace heat treatment furnace is mainly cemented carbide, ceramics, stainless steel materials, powder metallurgy, metal injection molding, vacuum sintering and dewaxing experiments and processes. It has the features of large pumping capacity, high vacuum, uniform and controllable temperature and no leakage. But what is the heat treatment process of the vacuum furnace? Please read this article carefully.

1. Process of Vacuum Heat Treatment Furnace

a. When the workpiece is quenched under vacuum, vacuum quenching oil should be used, which has a lower saturated vapor pressure.

b. The vacuum furnace should be maintained in a vacuum or pure nitrogen state to avoid inhalation and moisture absorption when not in use.

c. The pressure rise rate of domestic vacuum furnaces should not be greater than 1.33Pa/h, and the standard of some foreign companies is 0.67Pa/h.

d. The vacuum tempering furnace(Figure 1) should have a quick cooling device. The pressure of the cooling water should be greater than 0.2Mpa, and the flow rate should be adjustable.

e. When processing titanium alloys, it is not advisable to use nitrogen as a cooling gas, because titanium and nitrogen react at high temperatures to form golden yellow titanium nitride.

f. Cooling gas: 99.995% purity nitrogen is generally used for steel, 99.999% nitrogen or argon is used for high-temperature alloys, and 99.995% argon is used for titanium alloys.

g. Vacuum heating is mainly based on radiation, and the workpiece should be kept at a distance in the furnace.

h. During the heating process, the workpiece and the materials in the furnace will outgas, which will reduce the vacuum degree.

i. Heating up: After the workpiece is put in, it can be heated up when it is pre-pumped to 6.67Pa.

j. The heating temperature for vacuum tempering, vacuum annealing, vacuum solution treatment and vacuum aging is generally the same as the heating temperature for conventional treatment.

2. Features and Uses of Vacuum Heat Treatment Furnace

2.1 Features of Small Vacuum Heat Treatment Furnace Below 1300℃:

a. Using polycrystalline fiber furnace, energy saving and corrosion resistance.

b. The furnace chamber is made of imported energy-saving materials, and the energy consumption of the whole machine is only 1/3 of the same traditional electric furnace, which is energy-saving and environmentally friendly

c. Double-layer inner furnace shell with double-layer inner furnace shell, equipped with air-cooling system, rapid temperature rise and fall.

d. The whole furnace body adopts a double-layer inner liner structure, with an air gap in the middle, and the surface of the furnace body can even be touched safely without scorching feeling.

e. Alloy heating wire, built-in alloy heating wire, fast heating, long life.

f. The heating element adopts high-quality embedded alloy heating wire, which has high heating efficiency, high temperature resistance, oxidation resistance, corrosion resistance, fast heating, long life, small high temperature deformation, convenient installation and maintenance, and long service life.

g. Microcomputer PID controller Microcomputer PID controller, easy to operate, accurate, reliable and safe multi-segment programmable control of temperature control, which can simplify the complicated test process and truly realize automatic control and operation.

h. The furnace body is equipped with output voltage and output current monitoring meters, and the heating status of the furnace is clear at a glance.

▲Main application: Suitable for sintering of electronic ceramics and high-temperature structural ceramics, precision annealing of glass, mold processing and microcrystallization, precision annealing of crystals, preparation of ceramic glazes, powder metallurgy, sintering of nanomaterials, quenching of metal parts, and everything else The heat treatment that requires rapid heating process is an ideal experiment and production equipment for scientific research institutions, universities, industrial and mining enterprises.

E.g. Vacuum  Annealing Furnace＆Vacuum Sintering Furnace

2.2 Features of 1400℃～1600℃ Heat Shield Vacuum Heat Treatment Furnace:

a. Integrated design, compact structure, beautiful appearance, with casters, convenient and quick to move

b. The horizontal structure is used to open the door on the side, the structure is exquisite, and the loading and unloading is convenient

c. The touch screen display conventional control operation is simple and intuitive. 16 sintering processes can be pre-stored in the touch screen, which can be edited once and then directly used in the future. This saves the trouble of multiple editing processes and avoids input errors and product burnout.

d. The sintering temperature data can be recorded in real time, the data can be queried, and can be exported and downloaded

e. The sintering vacuum degree is high, the vacuum degree can reach 6.7*10-³pa, so as to ensure that the product is not oxidized.

f. With its own water cooler, save the trouble of waterway engineering.

▲Main application:  Used for vacuum heat treatment, vacuum degreasing, vacuum brazing and vacuum sintering of high-speed steel, cold and hot work die steel, martensitic stainless steel, elastic alloys, high-temperature alloys, magnetic materials and titanium alloys. It is also suitable for vacuum heat treatment, vacuum degreasing, vacuum brazing and vacuum sintering of high-speed steel, cold and hot work die steel, martensitic stainless steel, elastic alloy, high-temperature alloy, magnetic material and titanium alloy. Mass production of the same steel grade is also suitable for multi-specification, multi-variety single-piece or small batch production.

E.g. Vacuum Carburizing Furnace

※Notes :

a. When using a vacuum furnace to process titanium alloys, it is not advisable to use nitrogen as a cooling gas, because titanium and nitrogen react at high temperatures to form golden yellow titanium nitride.

b. The maintenance of the vacuum furnace should be in a vacuum or pure nitrogen state, avoid contact with air, and pay attention to inhalation and moisture absorption when not in use.

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

d. When the workpiece is quenched under vacuum, vacuum quenching oil with lower saturated vapor pressure should be used.

e. Vacuum furnace cooling gas: 99.995% purity nitrogen is generally used for steel, 99.999% nitrogen or argon is used for high-temperature alloys, and 99.995% argon is used for titanium alloys.

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

g. Vacuum heating is mainly based on radiation, and the workpiece should be kept at a distance in the furnace.

h. After the workpiece is put in, it is generally pre-pumped to 6.67Pa before heating. During the heating process, the workpiece and the materials in the furnace will outgas, which reduces the vacuum.