The pure metal is very reactive chemically and rapidly corrodes, especially in moist air or at elevated temperatures. The alpha form is magnetic, but when transformed into the beta form, the magnetism disappears although the lattice remains unchanged. The relations of these forms are peculiar. It is hard, brittle, fairly fusible, and is used to produce other alloys, including steel. Carbon steel is an alloy of iron with carbon, with small amounts of Mn, S, P, and Si.
Alloy steels are carbon steels with other additives such as nickel, chromium, vanadium, etc.
Iron is the cheapest and most abundant, useful, and important of all metals.