Any of a number of alloys consisting predominantly of iron with varying proportions of carbon (up to 1.7%) and, in some cases, small quantities of other elements (alloy steels), such as manganese, silicon, chromium, molybdenum, and nickel. Steels containing over 11–12% of chromium are known as stainless steels.
Carbon steels exist in three stable crystalline phases: ferrite has a body-centred cubic crystal, austenite has a face-centred cubic crystal, and cementite has an orthorhombic crystal. Pearlite is a mixture of ferrite and cementite arranged in parallel plates. The phase diagram shows how the phases form at different temperatures and compositions.
Steels are manufactured by the basic-oxygen process (L-D process), which has largely replaced the Bessemer process and the open-hearth process, or in electrical furnaces.
Steel
