Influence of Steel Cleanliness by Ladle Furnace Processes

Abstract

Non-metallic inclusions in steel can be treated by ladle metallurgy processes. Main ladle metallurgy processes that influence composition, morphology and quantity of non-metallic inclusions in steel are: deep deoxidation by Al wire injection; desulphuration by refining slag; alloying to final chemical composition; modification of alumina inclusions by additions of CaSi and/or CaO; elimination of non-metallic inclusions. Employing methods for determination of composition, morphology and quantity of non-metallic inclusions, formation of alumina inclusions during deep deoxidation of steel melt by Al wire injection, modification of alumina inclusions by Ca based additions were investigated. It is shown that elimination of non-metallic inclusions is a result of steel melt bath agitation by Ar gas bubbling. Composition and structure of slag from ladle metallurgy treatment are provided.