Iron and Steel

Iron is less reactive than , and so can be extracted from its oxides by reduction with carbon. This is done in a blast furnace. The Carbon displaces the Iron, this can be represented by the following word equation:

Iron Oxide + Carbon → Iron + Carbon Dioxide

The Iron from a blast furnace is known as 'Cast Iron'. It contains about 96% iron and 4% which is mainly carbon. The impurities make it and so it has limited uses, however it does have excellent strength in which means it can be used for bridges.

Iron Bridge, Shropshire - the world's first Iron Bridge

Removing all of the impurities would produce iron. Pure iron has a regular arrangement of atoms, with layers that can easily slide over each other. This makes it and easily shaped.

Pure iron is too soft for many uses, so most iron is converted into steels. Steels are alloys since they are mixtures of iron with carbon and other metals.

The different sized atoms added distort the layers in the structure of the pure metal, making it more difficult for them to slide over each other, and so alloys are harder. It is the microscopic atomic structure that results in the macroscopic properties we use to select material for a given job.

Alloys can be designed to have properties for specific uses:

Steel Alloy	Additives	Properties	Uses
Low Carbon Steels	0.1% Carbon	relatively soft and easily shaped	Car Bodies
High Carbon Steels	1.5% Carbon	hard, stiff	Blades for cutting tool constructions like bridges
Stainless Steels	Chromium	resistant to corrosion	Cutlery, sinks marine nuts and bolts