Features and application range of vacuum annealing

Due to a series of characteristics of vacuum heat treatment, this modern new process has been rapidly developed and widely used. From the perspective of processing materials, this process can process carbon steel, stainless steel, alloy steel, heat-resistant alloy, magnetic material, titanium and titanium alloy, zirconium and zirconium alloy, tool steel (including mold steel, cutting tool steel). From the perspective of product components, aircraft wing beams, landing gear, high-strength bolts and other structural parts in the aviation industry, gears, shafts, tools, fixtures, molds, etc. in mechanical manufacturing all need vacuum heat treatment. From the perspective of the application process field, vacuum heat treatment is required in machinery, metallurgy, energy, transportation, aerospace, aviation, navigation, weapons, construction, light industry, textiles, chemicals, petroleum, electronics, electrical appliances and other industries. Vacuum heat treatment plays an important role in the upgrading of mechanical and electronic products, improving product quality, saving energy and reducing consumption, giving full play to material potential, and increasing product life. The following introduces the characteristics and application scope of vacuum annealing heat treatment.

Characteristics of vacuum annealing

Due to the degassing, degreasing and rust removal effects of vacuum heating, the gas dissolved in the metal is easily discharged, so the surface of the parts after vacuum annealing is clean and bright. During vacuum annealing, the deformed grains produced by pressure processing are restored, and new grains are formed at the same time, making the structure uniform and refined, thereby changing the mechanical properties of the material. After vacuum annealing, there is no trace of lubricant on the surface of the material, and the surface is dry. It can be directly electroplated without the cleaning process of pickling or sandblasting, so as to achieve the purpose of shortening the process flow and improving product quality.

Application scope of vacuum annealing

(1) Vacuum annealing of refractory metals. Metals such as molybdenum, tungsten, tantalum, cobalt, vanadium, and zirconium have high melting points and are easily oxidized and easily contaminated by refractory materials. They have high strength and hardness during processing. If they contain gases such as hydrogen, oxygen, and nitrogen, the ductility of the material will deteriorate. In order to turn them into profiles, these materials must be softened after vacuum annealing before pressure processing.
(2) Vacuum annealing of soft magnetic alloys. Soft magnetic alloys are generally obtained by vacuum melting and vacuum rolling. Because they must maintain stable magnetic properties under the action of temperature, pressure, radiation and mechanical load, vacuum annealing is required.
(3) Vacuum annealing of silicon steel sheets. Vacuum annealing is required to remove gases such as hydrogen, carbon monoxide, carbon dioxide, and methane from silicon steel sheets, remove oxides and sulfides, eliminate internal stress and grain boundary distortion, increase magnetic induction intensity, and reduce unit iron loss.
(4) Vacuum annealing of iron-nickel alloys and iron-silicon alloys. The purpose is to improve the organizational structure and toughness.
(5) Vacuum annealing of electrical steel. The purpose is to improve plasticity and uniform magnetic properties.
(6) Vacuum annealing of stainless steel. The purpose is to improve the resistance of stainless steel to intergranular corrosion.
(7) Vacuum annealing of structural steel. The purpose is to improve strength and surface brightness.
(8) Vacuum annealing of steel wire and thermocouple wire. The purpose is to obtain a bright surface, eliminate processing stress, and remove harmful gases such as nitrogen and oxygen contained in the metal wire.

Vacuum Annealing Furnace