How Does Tungsten Crucible Maintain And Chemical Property

Nov 20, 2019

Tungsten crucible is a kind of industrial production equipment which is processed by tungsten metal under special technology. Maintenance should be paid attention to in the process of use, especially the maintenance of new crucible is very important. Therefore, the charging and melting of crucible should be carried out strictly according to the operating rules, so as to avoid premature damage of crucible or other accidents. After each smelting, the melting condition of the crucible should be observed. If the tungsten crucible is badly damaged, it should be repaired in time. Repair when the use of hot and cold repair. The size ratio of repair material should be consistent with the choice of lining material. The amount of boric acid can be slightly higher. Special circumstances can add a small amount of water or sodium silicate, for crucible was badly damaged, can stay after cooling, the surface layer of the crucible with a certain process to strip off, and then repair the furnace bottom first, reoccupy scraper scrape the bottom of the crucible shapes, the last sample mould is put in the tungsten crucible, crucible wall knot and repair work. Tungsten crucible is one of the metal tungsten products, mainly divided into sintering forming (applied to powder metallurgy technology), stamping forming, spinning type. Tungsten rods are used for turning and forming (generally smaller in size), and various forms are formed by welding. [2] pure tungsten plates, tungsten slices and pure tungsten rods are processed by corresponding processes.

Tungsten crucible can be used in vacuum inert gases up to 2600 degrees. Tungsten melting point boiling point, high temperature strength, corrosion resistance, high heat conductivity, small coefficient of thermal expansion, hardenability. Tungsten crucible is widely used in rare earth smelting, quartz glass, electronic spraying, crystal growth and other industries.

Tungsten is a rare high melting point metal, and can improve the high temperature hardness of steel, belongs to the periodic table 6 cycles Ⅵ group B (2) for a long period of time. Tungsten is a silver-white metal, shaped like steel. Tungsten has a high melting point, a low vapor pressure, and a low evaporation rate. Tungsten chemical property is very stable, normal temperature does not react with air and water, when not heated, any concentration of hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid and wang shui do not have an effect on tungsten, when the temperature rises to, above all kinds of acid, except hydrofluoric acid, other acid weak effect on tungsten. At room temperature, tungsten can be quickly dissolved in a mixture of hydrofluoric acid and concentrated nitric acid, but not in alkaline solution. In the presence of air, the molten alkali can oxidize tungsten to tungstate, which reacts more violently in the presence of oxidants (NaNO3, NaNO2, KClO3, PbO2). It can be combined with chlorine, bromine, iodine, carbon, nitrogen and sulfur at high temperature, but not hydrogenated.