FeMn

FeMn, short for ferro manganese, is an iron–manganese alloy produced for use in steelmaking. It is designed to add manganese to steel, functioning as a deoxidizer and desulfurizer and as an alloying element that improves toughness, strength, and hardenability. Ferro manganese is produced by smelting manganese-bearing ore with iron ore and carbon in a furnace, typically in a blast furnace or electric arc furnace.

FeMn grades vary by carbon and manganese content. The two main commercial categories are high-carbon ferro manganese and medium-carbon ferro manganese, with low-carbon variants produced for certain stainless and specialty steels. Composition is dominated by manganese, with iron as the balance and smaller amounts of silicon, phosphorus, sulfur and other impurities that are controlled in specification.

In steelmaking, FeMn serves several functions. It raises the manganese content of steel, acts as a deoxidizer and desulfurizer, and helps improve ductility, toughness and hardenability. It can also modify austenite stability and hot-working properties, reducing the risk of brittle fracture.

Common applications include structural and construction steels, automotive sheet steel, tool steels, and some stainless steels, where manganese is used to tailor properties and replace some nickel or chromium in certain alloys. Ferro manganese is a key ferroalloy due to its relatively favorable cost and broad impact on steel quality.

See also: Ferroalloys, manganese.