Common Iron-silicon Alloys

A high-silicon master alloy used for making silicon steel and adding silicon to transformer iron and steel by melting quartz or silica together with iron filings and carbon in an electric furnace. There are various grades for sale, containing 15-90% silicon. Silicon is combined with iron, but alloys with more than about 30% silicon are brittle and unstable. Silicon also causes carbon to precipitate in the form of graphite flakes, and alloys with high silicon content are called silicon metal. One manufacturer sells 2 grades containing 15% and 45% silicon; while another manufacturer produces 5 grades: 15%, 50%, 75%, 85% and 90% silicon, and sells grades containing 80-95% silicon, It is used in small ladle additions for the production of high silicon steels, and also in the production of hydrogen by reaction with caustic soda. Alloys are sold in bulk or crushed form. Silicon is usually added to steel by alloying it with reducing agents or other alloying elements. FeSiAl containing 12-15% Al is a more effective steel reducing agent than Al addition alone. Also used to add silicon to cast aluminum alloys, Union Carbide's selvatz is an iron-silicon-aluminum containing vanadium and zirconium. This alloy acts as a reducing agent, melts slag inclusions, and can also control the grain size of the steel. The Ohio Ferroalloy Company's Zemanal is a reduced alloy containing 20% each of silicon, aluminum, and manganese. Alcerfe produced by Vanadium Company contains 40% silicon, 20% aluminium and 40% iron. Both aluminum and silicon are in the form of aluminum silicate forming slag, which is removed when the steel is cast. Alcemin is a Swiss iron-silicon-alumina containing 50% aluminum. Silicon aluminum is an intermediate alloy in which silicon is added to the aluminum alloy, which does not contain iron.