Tungsten

The basic use：

tungsten is about 50% for smelting high-quality steel, about 35% for producing hard steel, about 10% for making tungsten wire, and about 5% for other purposes. Tungsten can be used to make firearms, rocket propulsion nozzles, armor-piercing bullets, metal cutting blades, drills, super-hard molds, wire drawing dies, etc. Tungsten has a wide range of uses, involving mining, metallurgy, machinery, construction, transportation, electronics, chemicals, light industry, textiles, military industry, aerospace, science and technology, and various industrial fields.

Iron and steel industry:

Most of tungsten is used to produce special steel. The widely used high-speed steel contains 9%-24% tungsten, 3.8%-4.6% chromium, 1%-5% vanadium, 4%-7% cobalt, and 0.7%-1.5% carbon. The characteristic of high-speed steel is that it can automatically quench at a high strengthening tempering temperature (700-800℃) in air, so it can maintain high hardness and wear resistance until 600-650℃. Tungsten steel in alloy tool steel contains 0.8%-1.2% tungsten; chromium 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 manufacture various tools: such as drill bits, milling cutters, wire drawing dies, female and male dies, gas support tools and other parts. Tungsten magnet steel is a permanent magnet steel containing 5.2%-6.2% tungsten, 0.68%-0.78% carbon, and 0.3%-0.5% chromium. Tungsten cobalt magnet steel contains 11.5%-14.5% tungsten, 5.5%-6.5% molybdenum, and 11.5%-12.5% ​​cobalt. They have high magnetization intensity and coercive force.

Electro-vacuum lighting materials:

Tungsten is used in the production of electron tubes, radio electronics and X-ray technology in the form of tungsten wire, tungsten ribbon and various forged components. Tungsten is the best material for white woven filaments and spiral wires. High operating temperature (2200-2500℃) ensures high luminous efficiency, while low evaporation rate ensures long life of the wire. Tungsten wire is used to make direct-heated cathodes and grids of electronic oscillator tubes, cathodes of high-voltage rectifiers and side-heated cathode heaters in various electronic instruments. Tungsten is used to make counter cathodes and cathodes of X-ray tubes and gas discharge tubes, as well as contacts of radio equipment and electrodes of atomic hydrogen welding guns. Tungsten wires and tungsten rods are used as heaters for high-temperature furnaces (3000℃). Tungsten heaters work in hydrogen gas, inert gas or vacuum.

Tungsten compounds:

Sodium tungstate is used to produce certain types of paints and pigments, as well as in the textile industry for cloth weighting and mixed with ammonium sulfate and ammonium phosphate to make fire-resistant and waterproof cloth. It is also used in the manufacture of metallic tungsten, tungstic acid and tungstates, as well as dyes, pigments, inks, electroplating, etc. It is also used as a catalyst, etc. Tungstic acid is a mordant and dye in the textile industry and a catalyst for the production of high-octane gasoline in the chemical industry. Tungsten disulfide is used as a solid lubricant and catalyst in organic synthesis, such as in the production of synthetic gasoline. Tungsten trioxide can be obtained when treating tungsten ore, and tungsten trioxide is reduced with hydrogen to produce tungsten powder, which is widely used as raw material for tungsten materials and tungsten metallurgy.

Contact materials and high-density alloys:

Tungsten-copper alloys (10%-40% copper) and tungsten-silver alloys made by powder metallurgy have the good electrical conductivity and thermal conductivity of copper and silver and the wear resistance of tungsten. Therefore, it becomes a very effective contact material for the working parts of knife switches, circuit breakers, spot welding electrodes, etc. High-density alloys with a composition of 90%-95% tungsten, 1%-6% nickel, and 1%-4% copper, as well as alloys with iron instead of copper, are used to manufacture gyroscope rotors, aircraft, balance weights for control rudders, radiation shields and baskets for radioactive isotopes, etc.

Heat-resistant and wear-resistant alloys:

As the most refractory metal, tungsten is a component of many heat-resistant alloys, such as alloys composed of 3%-15% tungsten, 25%-35% chromium, 45%-65% cobalt, and 0.5%-0.75% carbon. They are mainly used for highly wear-resistant parts, such as valves of aircraft engines, working parts of die hot cutters, turbine impellers, excavation equipment, and surface coatings of plowshares.

In aerospace rocket technology, as well as other sectors that require high thermal strength of machine parts, engines and some instruments, alloys of tungsten and other refractory metals (such as tantalum, niobium, molybdenum, and rhenium) are used as heat-resistant materials.

Tungsten carbide-based cemented carbide:

Tungsten carbide has high hardness, wear resistance and refractory properties. These alloys contain 85%-95% tungsten carbide and 5%-14% cobalt, which is used as a binder metal to give the alloy the necessary strength. It is mainly used for processing steel in some alloys, and also contains titanium, tantalum and niobium carbides. All these alloys are made by powder metallurgy. When heated to 1000-1100℃, it still has high hardness and wear resistance. The cutting speed of cemented carbide tools far exceeds that of the best tool steel tools. Cemented carbide is mainly used for cutting tools, mining tools and wire drawing dies.

In aviation and rocket technology, in other sectors where we require high thermal strength of machine parts, engines and some instruments, alloys of tungsten with other refractory metals (tantalum, niobium, molybdenum, rhenium) are used as thermally resistant materials.