Alloys of iron and carbon
made by remelting the crude iron produced
in a blast furnace. The carbon content is
usually between 2.4 and 4.0% and may be
present as iron carbide (white cast iron) or
as graphite (gray cast iron). Metals can be
added to improve the properties of the
alloy. Additional elements such as phosphorus,
sulfur, and manganese are also
present as impurities. Cast iron is a cheap
metal with an extensive range of possible
properties and it has been used on a very
large scale.