Tungsten

Tungsten is the refractory metal with the highest melting point. As a refractory metal, the most important advantage of tungsten is that it has good high-temperature strength, good corrosion resistance to molten alkali metal and vapor. Tungsten only appears oxide volatilization and liquid phase oxide at temperature more than 1000°C. However, it also has the disadvantage of high duct-brittle transition temperature and difficulty in plastic machining at room temperature.
The refractory metal represented by tungsten has been widely used in metallurgy, communication, chemical industry, electronic light source, aerospace, medicine, photosensitive, energy, catalyst and machinery industry.
After smelting tungsten is silver-white shiny metal, tungsten melting point and hardness are very high, the vapor pressure is very low, evaporation rate is small, normal temperature is not eroded by air, chemical properties are relatively stable. Tungsten is mainly used in filament and high speed cutting alloy steel, super hard die, also used in optical instruments, chemical instruments.
Tungsten is a strategic metal and a typical rare metal with very important applications. It is an important part of modern high-tech new materials, a series of electronic optical materials, special alloy, new functional materials and organic metal compounds need to use tungsten with unique properties.

Tungsten is a rare metal with high melting point, which can improve the hardness of steel at high temperature. Tungsten is a silver-white metal that looks like steel. Tungsten has a high melting point, low vapor pressure, and low evaporation rate. Tungsten is chemically stable and does not react with air or water at room temperature. Without heating, any concentration of hydrofluoric acid, sulfuric acid, nitric acid and aqua regia have no effect on tungsten. When the temperature rises to 80-100°C, the acids except hydrofluoric acid have a weak effect on tungsten. Tungsten dissolves quickly in a mixture of hydrofluoric acid and concentrated nitric acid at room temperature, but does not work in alkaline solutions. In the presence of air, the molten alkali can oxidize tungsten to tungstate, and in the presence of an oxidizer (NaNO3 NaNO2 KClO3 PbO2), the reaction to produce tungstate is even more violent. It can be combined with oxygen, fluorine, chlorobromine, iodine, carbon, nitrogen and sulfur at high temperature, but not with hydrogen.

Melting poits: 3410°C
Solid density: 19.25 g/cm3
Liquid density: 17.6 g/cm3
Thermal expansion coefficient: 4.5 x 10-6/°C
Thermal conductivity: 174 w/(m·k)
Specific heat: 130 J/kg·K(300K)
Elastic modulus: 35000-38000 MPa(wire)

Pure tungsten is a silver-white metal, and only powdered or filamentous tungsten is gray or black.
Tungsten is very heavy and very hard.
Tungsten is the most heat-resistant metal, and tungsten steel inherits this excellent property. Turning tools made of tungsten steel are as hard as ever at temperatures up to 1000°C. The use of tungsten steel turning tool increases the metal cutting speed by 200 times, up to more than 2000 meters per minute.
Gun barrels are also commonly made of tungsten steel, because in the continuous firing, the barrel of the gun will be scalded by the friction of shells or bullets, but the heat resistant tungsten steel still maintains good elasticity and mechanical strength.

Basic application of tungsten
About 50% of the tungsten mined in the world is used for smelting high-quality steel, about 35% for producing hard steel, about 10% for producing tungsten wire, and about 5% for other purposes. Tungsten can be used to make firearms, rocket thruster nozzle, armet-piercing projectile, cutting metal blade, drill bit, super-hard die, wire drawing die, etc.
Tungsten in pure metal state and alloy state is widely used in modern technology. The main alloy states are alloy steel, tungsten carbide based cemented carbide, wear resistant alloy and strong heat alloy.

Precision seamless tube

• _◎ OD 6.0 ~ 100.0 mm
• _◎ ID 3.0 ~ 80.0 mm