Niobium and tantalum are often associated with each other, but the content of niobium in the earth's crust is about 2.4 × 10 -3 %, which is 10 times that of tantalum, mainly in the form of niobite. Generally, the corrosion resistance of niobium is higher than that of titanium and zirconium and slightly lower than that of tantalum. Since the price of niobium is lower than that of tantalum, niobium can be used to replace more expensive tantalum in some corrosive media. At the same time, the relative density of niobium is only about 1/2 of that of tantalum, which can reduce the cost.
Like tantalum, niobium becomes a passive corrosion-resistant metal by forming a dense oxide film on the surface, so the corrosion resistance of niobium is close to that of tantalum. Niobium is mainly used in some strong reducing acid mediums with low temperature, but it is not resistant to corrosion in hydrofluoric acid, hot concentrated sulfuric acid, sodium hydroxide, potassium hydroxide, and other media, in hot concentrated hydrochloric acid, and hot concentrated phosphoric acid. The corrosion rate of niobium is also high, and niobium should be used with caution in these media.
The boiling point of niobium is; 4927 ℃, and the melting point is: 2468 ℃, it is a refractory metal. Niobium can be formed at a medium temperature of 350~400 ℃, formed at a high temperature of 950~1000 ℃, and can be fully annealed at about 1200 ℃. Niobium starts to oxidize at 230 ℃ in the air and starts to oxidize strongly at 300 ℃. When the temperature is higher than 400 ℃, the oxide film is destroyed and peeled off, which greatly accelerates the oxidation rate. Niobium begins to nitride at 600 °C in the air. Niobium has been used in pressure vessels to some extent, but there is no formal standard for niobium vessels. In the pressure vessel, pure niobium is mainly used, and the addition of about 1% zirconium can improve the strength, but the corrosion resistance and plasticity are slightly reduced.
American Niobium Standard:
Standard No. Standard Name
ASTMB393-2003 Niobium Sheet, Sheet, Strip
ASTMB392-2003 Niobium bar and wire
ASTMB394-2003 Niobium seamless pipe, welded pipe
Chinese Niobium Standard:
Standard number Standard name
GB/T3630-1983 Niobium sheet, strip, and foil
GB/T14842-1993 Niobium seamless tube
GB/T8183-1987 Tantalum and Tantalum Alloy Foil
GB/T6869-1998 Niobium bar
Baoji Yusheng Metal Technology Co., Ltd. has the ability to produce various specifications of seamless niobium tubes, niobium bars, niobium wires, niobium foils, niobium sheets, and other metals and their alloy products. If you have special customer requirements for niobium sheets, please contact us in time, for quick results.
