Thirteen Steps of Steelmaking in an Electric Arc Furnace

Steelmaking in an electric arc furnace (EAF) is a complex process consisting of thirteen main steps:

  1. Charging – Adding raw materials such as molten iron or scrap steel into the furnace.
  2. Slag Formation – Adjusting the slag composition, alkalinity, viscosity, and reactivity to facilitate refining. For example, oxygen blowing ensures slag has sufficient fluidity and alkalinity to remove sulfur and phosphorus efficiently.
  3. Slag Removal – Removing slag during specific stages of the process, depending on the refining method.
  4. Molten Pool Stirring – Enhancing metallurgical reactions by agitating the molten metal and slag through gas, mechanical, or electromagnetic methods.
  5. Dephosphorization – Reducing phosphorus content in the steel to prevent brittleness.
  6. Bottom Blowing – Injecting gases such as N₂, Ar, CO₂, CO, CH₄, or O₂ through nozzles at the furnace bottom to accelerate melting and improve reactions.
  7. Melting Period – From initial power-on to complete melting of furnace charge, the goal is rapid melting, heating, and slag formation.
  8. Oxidation and Decarburization – Removing carbon, phosphorus, gases, and inclusions to purify steel and raise temperature uniformly.
  9. Refining Period – Removing harmful elements through chemical reactions to ensure steel quality.
  10. Reduction Period – After slag removal until tapping, controlling composition, temperature, and performing desulfurization and deoxidation.
  11. Secondary Refining (Ladle Metallurgy) – Transferring steel to another vessel for degassing, desulfurization, deoxidation, and minor composition adjustments under vacuum or protective atmospheres.
  12. Molten Steel Stirring – Stirring during secondary refining to ensure uniform composition and temperature, accelerating metallurgical reactions, and removing inclusions efficiently.
  13. Wire Feeding into Ladle – Adding powders or wires (e.g., Ca-Si, Al, C) for deep desulfurization, deoxidation, and minor chemical adjustments, while cleaning the steel and improving inclusion morphology.

These thirteen steps collectively ensure high-quality steel production in a modern EAF.