stålfrämställning

Stålfrämställning refers to the process of producing steel, an alloy of iron and carbon, along with other elements to improve its properties. The primary method for steel production is the basic oxygen steelmaking (BOS) process, formerly known as the oxygen converter process. In this method, molten pig iron, produced from iron ore in a blast furnace, is transferred to a BOS converter. High-purity oxygen is then blown onto the surface of the molten metal at supersonic speeds. This oxygen reacts with impurities such as carbon, silicon, manganese, and phosphorus, oxidizing them. The carbon is primarily removed as carbon monoxide gas, while other impurities form slag with added fluxes like lime. The intense heat generated by these exothermic reactions melts any remaining scrap steel that is added to the charge. Once the desired composition is achieved, the molten steel is tapped from the converter. Another significant method is the electric arc furnace (EAF) process, which uses electricity to melt scrap steel and virgin iron. EAFs are versatile and can produce a wide range of steel types, including specialty steels. Following the initial steelmaking process, further refining might occur in secondary metallurgy steps, such as ladle metallurgy, to precisely control the steel's composition and remove dissolved gases. The final stage involves casting the molten steel into solid forms, such as continuous casting into slabs, blooms, or billets, which are then further processed into various steel products.