Niobium and niobium alloys in corrosive applications

Niobium and niobium alloys have been used in a number of industries and applications for many years. These applications include alloying in steels and reactive metals, cathodic protection anodes, superconductivity, rocket nozzles, rivets for aircraft, sodium vapor lamps, jewelry, oxygen lances for pressure oxidation of ores, as well as chemical processing applications. During the past 10–15 years, niobium has been considered and applied in more and more chemical processing applications because it exhibits excellent corrosion resistance in many environments. Important chemical processing applications for niobium alloys include hydrochloric acid, nitric acid, sulfuric acid, chromic acid, organic acids, salts and liquid metals. This paper will describe the corrosion resistance of niobium in a variety of environments. It will also show those applications that niobium and its alloys are currently being used in, and describe those applications being considered for the future. (AU)