niobium alloy bar
Niobium, like tantalum, relies on the formation of a dense oxide film on the surface to become a passivating corrosion-resistant metal. Therefore, the corrosion resistance of niobium is close to that of tantalum. Niobium is mainly used in some strong reducing acid media with low temperature. However, it is not corrosion resistant in hydrofluoric acid, hot concentrated sulfuric acid, sodium hydroxide, potassium hydroxide and other media. It is not corrosion resistant in hot concentrated hydrochloric acid and hot concentrated phosphoric acid. The corrosion rate is also high, so caution should be used when applying niobium in these media.
Pure Niobium Crucible
The boiling point of niobium is: 4927 ℃, the melting point is: 2468 ℃, it is a refractory metal. Niobium can be molded at medium temperatures of 350~400°C, high temperature molding at 950~1000°C, and can be completely annealed at around 1200°C. Niobium begins to oxidize in air at 230°C, and begins to oxidize strongly at 300°C. When the temperature is higher than 400°C, the oxide film is destroyed and falls off, greatly accelerating the oxidation rate. Niobium begins to nitride in air at 600°C. Niobium will absorb hydrogen in a hydrogen-containing medium at 250 ℃ ~950 ℃.
Pure Niobium Tube
Niobium materials have been used to some extent in pressure vessels, but there is no formal standard for niobium vessels. Pure niobium is mainly used in pressure vessels. Adding about 1% zirconium can increase the strength, but the corrosion resistance and plasticity are slightly reduced.
