COMMENTARY — Niobium: an important specialty metal

During the past 30 years, niobium has steadily emerged as an important specialty metal. In particular, steel-consuming industries have greatly benefited from the materials savings which result from using niobium micro-alloyed, high-strength, low-alloy (HSLA) steels.

Listed among applications for these niobium HSLA steels are high-pressure oil and gas pipelines, automobiles, trucks, ships, offshore drilling platforms, railway lines, seamless tubing for oil wells, concrete reinforcing bars, etc. Other significant consumers of niobium include aircraft engines, superconducting magnets and various nuclear-chemical plants. Niobium, unlike molybdenum, nickel, tungsten, manganese, silicon, etc., is not a commodity. It is not traded on the open market to any significant degree but, rather, is sold in an orderly manner through well-defined channels representing the various producers. Compared with the above metals, the annual consumption of niobium is small and it is therefore considered a specialty metal.

In 1982, it was projected that world niobium consumption would be about 55 million lb. of Nb2O5 equivalent by 1990. In reality, the niobium shipments in 1990 turned out to be more than 25% less than this prediction. It is clear that the growth rate experienced in the 1970s was replaced by little or no growth in the 1980s. Furthermore, the niobium business has experienced large fluctuations in demand from year to year.

Niobium was discovered in 1801 by English chemist Charles Hatchett. He named it columbium in honor of the New World because the mineral sample with which he was working came from New England in the U.S. However, Hatchett did not isolate the element. This was left to Heinrich Rose, a German, who separated an impure Nb2O5 from tantalite in 1844. Rose, thinking he had found a new element, re-named it niobium.

Applications for niobium began around 1925 when it was added to tool steel as a partial substitute for tungsten. Later, in 1933, it was first used to stabilize interstitials in austenitic stainless steel. This latter use became the major application of niobium for the next

30 years. Niobium was added to superalloys for use in gas turbines in the 1940s.

From a paper by Harry Stuart and Geoff Tither which appeared in a recent issue of the Tantalum-Niobium International Study Centres Bulletin.