Application field of tungsten and application of tungsten alloy
Tungsten is widely used in modern technology in pure metal state and alloy state. Alloy state is mainly alloy steel, tungsten carbide based hard alloy, wear resistant alloy and strong hot alloy. Tungsten is mainly used in the following industries:
Iron and steel industry
Tungsten is mostly used in specialty steels. Widely used in high speed steel containing 9%-24% of tungsten, 3.8% - 4.6% of chromium, 1% - 5% of the cobalt vanadium, 4%, 7%, 0.7%, 1.5% carbon. High-speed steel is characterized by its ability to be automatically hardened at a high tempering temperature (700-800C) in the air, so that it retains high hardness and wear resistance up to 600℃ to 650℃. The tungsten steel in the alloy tool steel contains 0.8%-1.2% tungsten; Chrome-tungsten silicon steel contains 2%-2.7% tungsten. Chromium tungsten steel contains 2%-9% tungsten; Chromium-tungsten-manganese steel contains 0.5%-1.6% tungsten. Tungsten-containing steel is used to make various tools; Such as drill, milling cutter, drawing die, male die and male die, gas support tools and other parts. Tungsten magnetic steel is a permanent magnet steel that contains 5.2% to 6.2% tungsten, 0.68% to 0.78% carbon, and 0.3% to 0.5% wains. Tungsten-cobalt magnetic steel contains 11.5%-14.5% tungsten, 5.5%-6.5% molybdenum, 11.5%-12.5% cobalt hard magnetic material. They have high magnetization.
Tungsten carbide based carbides
Tungsten carbide has high hardness, wear resistance and refractory properties. These alloys contain 85-95 percent tungsten carbide and 5-14 percent cobalt. Cobalt is used as a binder metal, which gives the alloy the necessary strength. Titanium and silver carbides are also found in some alloys used chiefly in making steel. All these alloys are made by means of powder metallurgy. They still have high hardness and wear resistance when heated to 1000-1100C. The cutting speed of carbide tool far exceeds that of steel tool. Cemented carbide is mainly used for cutting tools, mining tools and drawing dies.
Thermal strength and wear resistant alloy
Tungsten, as a refractory metal, is a component of many thermally strong alloys, such as 3%-15% tungsten, 25%-35% chromium, 45%-65% cobalt, and 0.5%-0.75% carbon. It is mainly used in highly wear-resistant parts, such as valves of aeroengines, working parts of hot cutting tools, turbine impellers, surface coating of excavating equipment and plowshares. Alloys of tungsten and other refractory metals (such as tantalum, molybdenum, rhenium) are used as thermally strong materials in aero-rocket technology, as well as in other sectors that require high thermal strength of machine parts, engines, and some instruments.
Contact material and high specific gravity alloy
Tungsten-copper alloy (10%-40% copper) and tungsten - silver alloy manufactured by powder metallurgy, both copper and silver have good electrical conductivity, thermal conductivity and wear resistance of tungsten. Therefore, it becomes the manufacturing knife switch. Very efficient contact material for working parts of circuit breakers, spot welding electrodes, etc. High specific gravity alloys made of 90%-95% tungsten, 1%-6% nickel, 1%-4% copper, and alloys made of iron instead of copper (-5%) are used in the manufacture of gyroscopes, rotors, airplanes, counterbalances for rudder control, radioactive isotope shields, tungsten alloy containers, etc., tungsten crucible for sapphire growth furnaces, tungsten electrode plates, etc.
Electric vacuum lighting material
Tungsten is used in tube production, radio electronics and X-ray technology with tungsten wires, tungsten bands and various forged components. Tungsten is a good material for white filament and spiral filament. High operating temperature (2200-2500 ℃) ensures high luminescence efficiency, and small evaporation speed ensures long life of wire. Tungsten wires are used in the manufacture of direct hot cathodes and grids for electronic oscillating tubes, cathodes for high voltage rectifiers and side hot cathode heaters for various electronic instruments. Tungsten is used as cathodes and countercathodes for X-ray and gas discharge tubes, as well as contacts for radio equipment and atomic hydrogen torch electrodes. The tungsten wire and tungsten rod serve as the heater of the high temperature furnace (3000' c). Tungsten heater in hydrogen gas. Work in inert gas or vacuum.
Tungsten compound
Sodium tungstate is used in the production of certain types of paints and pigments, as well as in the textile industry for cloth weighting and mixing with ammonium sulfate and ammonium phosphate to make fireproofing and tarpaulins. Also used in metal tungsten, tungstic acid and tungstic acid manufacturing and dye, pigment, ink, electroplating and other aspects. Also used as catalysts, etc. Tungstic acid is used as mordant and dye in textile industry and catalyst for high octane gasoline in chemical industry. Disulfide will be used as a solid lubricant and catalyst in organic synthesis, as in the manufacture of synthetic gasoline. Tungsten trioxide can be obtained when tungsten ore is treated, and tungsten powder is made by hydrogen reduction of tungsten trioxide, which is widely used in tungsten and tungsten gold materials.
