steel

Iron alloy containing carbon from as low as 0.03 percent (as in ingot steel) to 2.5 percent by weight (as in cast iron), and varying amounts of other elements (mainly chromium, manganese, molybdenum, nickel, and silicon) depending on its end use. Higher amounts of carbon make the steel more fluid and castable, and lower amounts make it purer for specialized purposes such as electrical steel and stainless steel. Carbon steel exits in three main stable crystalline forms: (1) Ferrite (body centered cubic crystal), (2) Austenite (face centered cubic crystal), and (3) Cementite (orthorhombic crystal). See also stainless Steel, ferritic stainless steels, and martensitic stainless steels.