Ferroalloys impart distinctive qualities to steel and cast iron and serve important functions during iron and steel production cycles. The principal ferroalloys are those of chromium, manganese, and silicon. Manganese, used to neutralize the harmful effect of sulfur and as an alloying element, is essential to the production of virtually all steels and is also important to the production of cast iron. Chromium adds corrosion resistance to stainless steels. Silicon is used primarily for the deoxidation of steel and as an alloying element in cast iron. Boron, cobalt, columbium, copper, molybdenum, nickel, phosphorus, titanium, tungsten, vanadium, zirconium, and the rare earths are among the other elements contributing to the character of the various alloy steels and cast irons. Most of these elements are normally added to the molten metal as a ferroalloy.
Ferroalloys and related materials are essential to the production of many metals and alloys, including aluminum, iron, and steel. The domestic ferroalloys industry has been in a state of decline since its peak production years in the early 1970's because of decreased demand and competition from low-priced imports. Since that time, many U.S. producers have gone out of business, leaving the domestic ferroalloy industry a lean but surviving element of the country's industrial base.
- Table 1.--Ferroalloys produced and shipped from furnaces in the United States