Niobium, a lustrous, silver-white, metallic chemical element. Until 1950, when the name niobium was officially adopted by the International Union of Pure and Applied Chemistry, the metal was also known as columbium in the United States. It is still called columbium in the metallurgy industry.
Niobium is soft, ductile (can be drawn into wire), and corrosion-resistant. It is used mainly as an alloy element in various steels. When alloyed with niobium, carbon steels and alloy steels become stronger and more impact-resistant and stainless steels become easier to weld. Niobium-bearing steels are used to make aircraft landing-gear assemblies, parts for construction machinery, and piping for chemical and food processing plants.
Niobium was discovered in 1801 by the English chemist Charles Hatchett. It is usually found in nature combined with tantalum and other chemical elements in the ores columbite, tantalite, and pyrochlore. The metal is obtained from the ores by chemical processes.
Symbol: Nb. Atomic number: 41. Atomic weight: 92.9064. Specific gravity: 8.57. Melting point: 4,474.4 F. (2,468 C.). Boiling point: 8,568 F. (4,742 C.). Niobium has one stable isotope: Nb-93. It belongs to Group V-B of the Periodic Table and may have a valence of +2, +3, or +5.