(Chemical symbol: Zr). A lustrous, steel-gray, somewhat brittle metal with a high melting point. It is used as an alloying agent in iron and aluminum, and is also used in nuclear reactors. Atomic number, 40; atomic weight, 91; melting point, 2350°C (4262°F); specific gravity, 6.25.
Zirconium is very hard and is sometimes used in hardfacing material because of its resistance to corrosion. When steel is alloyed with small amounts of zirconium, fine grain size is produced, and no aluminum additions to steel are required.
