Steel making is the process of producing steel from iron ore and/or scrap. In steel making, impurities such as nitrogen, phosphorus, sulfur, and excess carbon are removed from the raw iron, and alloying elements such as manganese, nickel, chromium, and vanadium are added to produce different grades of steel. The process also includes the addition of other elements such as molybdenum, titanium, and niobium to produce specialty steels. The steel making process involves several steps including melting, refining, alloying, and casting.