Control of inclusion characteristics in direct cast steel billets

Two main criteria are used to characterize steel cleanliness. First the num ber and size of inclusions must be at the minimum level achievable with sta te-of-the-art steelmaking and casting equipment and procedures. Second the remaining small inclusions must have a chemical composition suitable for th e steel application. In high carbon steel destined for wire drawing, inclus ions need to be as deformable as possible. In this paper the inclusion behavior during hot rolling continuously cast ( c.c.) billets to wire rods is reviewed. The relationship between inclusion deformability and composition was investigated at the laboratory scale and the results were applied to the control of cleanliness in c.c. billets. Pro duction parameters affecting steel cleanliness are discussed. (C) 2000 Cana dian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved.