Study on the Chemical Aspects of Non-Metallic Inclusions in Ladle Treatment

摘要

Non-metallic inclusions have become the major concern in the production of clean steels. Deoxidation of steel with aluminum wire injection is very commonly used today, and plays a crucial role in ladle metallurgy. The addition of aluminum not only results in the formation of alumina inclusions but also affects the inclusion chemistry. The manner and rate of nucleation of alumina have great impact on the deoxidation process. Hence, one of the preconditions to control the behaviour of inclusions in the ladle is a good understanding of the mechanism and the rate of alumina nucleation. Many researchers agree upon that homogeneous nucleation of inclusions can take place in regions, where the supersaturation of the deoxidizing element is very high. The present study was made to gain an insight into the effects of aluminum addition on the inclusions. The investigation is based on a mathematical modeling study in combination with experiments performed both in the laboratory and in the industry. While the modeling study and the laboratory experiments were more focused on the effects of aluminum addition, the industrial study was made to get an understanding of the inclusion chemistry and behaviours along the history of the ladle process.