Tungsten has remarkable corrosion resistance to many acids. It is resistant to hydrofluoric and hydrochloric acid and is only slightly attacked by hot hydrochloric and sulphuric acid.

Nitric acid and aqua regia also attack tungsten only slightly. On the other hand, mixtures of hydrofluoric and nitric acid dissolve tungsten rapidly.

Tungsten is stable in alkaline solutions, provided they do not contain oxidizing agents. Molten caustic soda attacks tungsten strongly in presence of oxidizers.

Tungsten is attacked by fluorine at ambient temperature, by chlorine from about 250℃ and by bromine and iodine above 500℃.

The corrosion resistance of tungsten to many molten metals is remarkable.

Tungsten has certain properties which must be taken into account when working the metal. A knowledge of these properties and of the following recommendations are prerequisites for successful working.

Transition temperature

Tungsten is brittle at ambient temperature. Like all metals with cubic centered lattice, tungsten has a “transition temperature” below which it cannot be worked due to its extreme brittleness and hardness. Above this temperature, it is ductile. The brittle-ductile transition temperature is mainly affected by impurities and previous thermomechanical history.

We will continue to talk about this topic in next article.

Molybdenum and tungsten manufacturer-Zhengzhou Sanhui Co., Ltd has been dealing in refractory metals for almost 25 years. Come to us for titanium, niobium, zirconium and other metal products.