The application of vacuum coating technology in steel strip surface treatment provides a new means for the development of new strip materials and an important technology of steel industry’s sustainable development.
The vacuum coating is evaporating the metal and other solid materials and forming a plating layer film on the surface of the deposition in the situation of gasification and vacuum. Most representative of the vacuum coating method is the resistance heating and electron gun heating. The former is the high melting point metal such as tungsten, etc. around the spiral shape, made resistance heater, power and Joule heat generated by the coating material to be placed in which the heating and evaporation. The latter is the use of electron gun heated coating material directly from the electron gun out of the electron beam in a magnetic field, guided by their bombardment coating material so that heat evaporation. More advanced vacuum coating is plasma vacuum coating, coating materials, evaporation, and then plasma gasification technology. After the plasma of particles can be applied to obtain very high voltage, etc. It is easy to form a dense, strong adhesion of the film.
Strip vacuum coating vacuum coating and the general difference is that it is a large area continuous coating process, the efficiency of the coating magnesia material evaporation, evaporation of the stability of the long, large-area uniformity of the coating with very high demands.
More mature, easy-to-strip method is to promote the electron beam coating technology. Abroad from the fifties of last century began the development of the technology developed. Among them, the power strip evaporation source is the key in the vacuum coating technology. With the electro-physical technology, high-power electron gun has been developed and applied, makes this technology from the laboratory to industrial production. Practice has proved that electron beam heating vacuum evaporation coating process for steel strip with a high energy density, high evaporation rates and high energy conversion rate of technological advantage.
The general vacuum strip coating process is: first strip in the atmosphere after cleaning, then into the vacuum decompression chamber, the electron gun warmed up, the coating material molecules or atoms deposited on the surface of the strip walking on the coating layer formed by the cooling. Strip back into the atmosphere via pressurized chamber, which is continuous to the air-to-air vacuum coating. In this process the key technologies are: vacuum conditions, using the electron gun emits a high energy density of the electron beam crucible coating material, the material melted, the vaporization of atoms, molecules into a certain amount of evaporation rate and the vapor pressure of the vapor cloud, set along a certain direction, the surface of the strip on the warm-up and activation, even after cooling to form a solid coating material layer.
At present, the international use of electron beam coating technology strip width of 1.25 meters, strip thickness of 1.2 mm, the electron gun power of 1,500 kilowatts, the maximum coating speed can reach 200 meters per minute, coating nickel oxide materials are also limited from the start aluminum, developed to be copper, nickel, titanium, chromium, stainless steel and other materials. in the late 1980s in China, East Germany first introduced the original design and production of EBA-300 type electron beam coating steel strip production line, this is a from the atmosphere into the atmosphere, including the pre-treatment units and the full continuous production line. Performance is now able to produce good quality, reasonable price, welcome to the steel strip coating by the user of new products.
The application of tungsten in various industries
Steel Industry Most of tungsten applied in the production of special steels. The widely used high-speed steel was containing 9-24% of tungsten, 3.8-4.6% of chromium, 1-5% of vanadium, 4-7% of cobalt, 0.7-1.5% of carbon.
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According to records, coconut oil can be regarded as the nobility of skin care plant extracts. It was rich in exotic tension of tropical plants, which can enhance the contractile force of the pores, perfectly beautify and nourish the skin.
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Nano-aluminum powder, a material with remarkable properties due to its minuscule particle size, is revolutionizing various industries with its high reactivity and large specific surface area. Unlike its bulk counterpart, nano-aluminum powder begins to oxidize at a lower temperature of 550°C, compared to the 950°C oxidation point of ordinary aluminum. This lower ignition energy and full combustion without apparent cohesion make it a superior choice for applications requiring high energy and efficiency. The unique characteristics of nano-aluminum powder, such as faster burning rates and greater heat release, are largely influenced by its synthesis method, which determines its particle size, surface area, and shape.
