hard steel that has passed through the liquid state in the manufacturing process and has been cast in ingot molds (to produce ingots) or casting molds (to produce castings). Ingot steel is contrasted with steel that was formerly produced by carburization of blooming, refined (ball), and puddled iron, as well as with modern cermets, which contain iron and carbon and are produced by sintering of metal powders. An ancient method for the production of ingot steel is the crucible process. Almost all of the steel produced in the second half of the 20th century is ingot steel smelted in oxygen converters, open-hearth furnaces, or arc furnaces.