Chemical names for rust include iron oxide, ferric oxide and hematite. The substance is also known by its chemical formula, Fe2O3, which represents the two elements--iron and oxygen--that compose rust.
Rust is both a substance and a verb describing the process that creates the substance. While corrosion is the result of oxidation leeching the metallic properties of metals such as iron, copper and aluminum, rusting is specifically the corrosion of iron. The process occurs most often in alloy steel. The brown- and red-colored flakes that appear on iron as the metal deteriorates during the process are referred to as rust.