Tungsten properties

Tungsten is a silver-white metal. It belongs to group VIB in the periodic table and is the metal with the highest melting point. There are about 20 kinds of tungsten minerals, among which industrial grades are hematite and scheelite.The melting point of tungsten is high, and the vapor pressure is still low at a high temperature of 2000-2500 °C. Tungsten has high hardness, high density and good high temperature strength.At room temperature, tungsten is stable in air and begins to lose its luster at 400 °C.Tungsten is oxidized to tungsten dioxide in water vapor above 600 °C.Tungsten is not easily eroded by acid, alkali solution and aqua regia at normal temperature, but is dissolved in a mixed acid of concentrated nitric acid and hydrofluoric acid.

The use of tungsten

Most of tungsten is used to produce cemented carbide and ferro-tungsten. Tungsten and chromium, molybdenum and cobalt are used to form heat-resistant and wear-resistant alloys for the production of tools, metal surface hardening materials, gas turbine blades and combustion tubes. Wires, rods, sheets, etc. of metal tungsten are used to make electric bulbs, components of the tubes, and electrodes for arc welding.