Steel is one of the most widely used materials, particularly in construction and engineering and in the manufacture of cars. It is estimated that there are over 20 billion tonnes of steel in use, equivalent to well over 2 tonnes for every person on Earth.
Steels are alloys of iron, carbon and other metals and non-metals. The composition of the steel is adjusted so that it has the precise properties needed.
The term alloy steel is confined to steels containing some combination of one or more of the following elements: nickel, chromium, tungsten, molybdenum, vanadium, manganese, cobalt, copper, niobium, zirconium, selenium and lead.Steels can be repeatedly recycled without any loss of performance.