Science, Tech, Math › Science The Modern Steel Manufacturing Process Removing Carbon From Iron Creates Steel Share Flipboard Email Print sdlgzps / Getty Images Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Terence Bell University of British Columbia Carleton University Terence Bell wrote about commodities investing for The Balance, and has over 10 years experience in the rare earth and minor metal industries. our editorial process Twitter Twitter LinkedIn LinkedIn Terence Bell Updated August 21, 2020 Steel is the world's most popular construction material because of its unique combination of durability, workability, and cost. It's an iron alloy that contains 0.2-2% carbon by weight. According to the World Steel Association, some of the largest steel-producing countries are China, India, Japan, and the U.S. China accounts for roughly 50% of this production. The world's largest steel producers include ArcelorMittal, China Baowu Group, Nippon Steel Corporation, and HBIS Group. The Modern Steel Production Process Methods for manufacturing steel have evolved significantly since industrial production began in the late 19th century. Modern methods, however, are still based on the same premise as the original Bessemer Process, which uses oxygen to lower the carbon content in iron. Today, steel production makes use of recycled materials as well as traditional raw materials, such as iron ore, coal, and limestone. Two processes, basic oxygen steelmaking (BOS) and electric arc furnaces (EAF), account for virtually all steel production. Ironmaking, the first step in making steel, involves the raw inputs of iron ore, coke, and lime being melted in a blast furnace. The resulting molten iron—also referred to as hot metal—still contains 4-4.5% carbon and other impurities that make it brittle. Primary steelmaking has two methods: BOS (Basic Oxygen Furnace) and the more modern EAF (Electric Arc Furnace) methods. The BOS method adds recycled scrap steel to the molten iron in a converter. At high temperatures, oxygen is blown through the metal, which reduces the carbon content to between 0-1.5%. The EAF method, however, feeds recycled steel scrap through high-power electric arcs (with temperatures of up to 1,650 degrees Celsius) to melt the metal and convert it into high-quality steel. Secondary steelmaking involves treating the molten steel produced from both BOS and EAF routes to adjust the steel composition. This is done by adding or removing certain elements and/or manipulating the temperature and production environment. Depending on the types of steel required, the following secondary steelmaking processes can be used: StirringLadle furnaceLadle injectionDegassingCAS-OB (composition adjustment by sealed argon bubbling with oxygen blowing) Continuous casting sees the molten steel cast into a cooled mold, causing a thin steel shell to solidify. The shell strand is withdrawn using guided rolls, then it's fully cooled and solidified. Next, the strand is cut depending on application—slabs for flat products (plate and strip), blooms for sections (beams), billets for long products (wires), or thin strips. In primary forming, the steel that is cast is then formed into various shapes, often by hot rolling, a process that eliminates cast defects and achieves the required shape and surface quality. Hot rolled products are divided into flat products, long products, seamless tubes, and specialty products. Finally, it's time for manufacturing, fabrication, and finishing. Secondary forming techniques give the steel its final shape and properties. These techniques include: Shaping (cold rolling), which is done below the metal's recrystallization point, meaning mechanical stress—not heat—affects changeMachining (drilling)Joining (welding)Coating (galvanizing)Heat treatment (tempering)Surface treatment (carburizing) View Article Sources ASM International. "Introduction to Steels and Cast Irons," Page 1. Accessed Jan. 13, 2020. World Steel Association. "World Steel Figures in 2019," Page 8. Accessed Jan. 13, 2020. Centre for Industry Education Collaboration. "Steel." Accessed Jan. 13, 2020. South East Asia Iron and Steel Institute. "The Making of Iron and Steel," Page 3. Accessed Jan. 13, 2020. South East Asia Iron and Steel Institute. "The Making of Iron and Steel," Page 23. Accessed Jan. 13, 2020. South East Asia Iron and Steel Institute. "The Making of Iron and Steel," Page 32. Accessed Jan. 13, 2020.