Untersuchung des Aufschmelzverhaltens von Gießpulver und der Schlacke-Schmelze-Interaktion im Meniskusbereich der Stranggießkokille

The adjustment of mould powder is a key factor to ensure a stable continuous casting (CC) process. Therefore, a comprehensive study was carried out to investigate the melting behavior of mould powder with a special focus on carbon which is decisive for the melting process and the interaction between slag and liquid steel in the meniscus area of the continuous casting mould. Newly-designed test setups were used to ob-serve the phase transformation and the carbon combustion during the melting process in the laboratory and under industrial conditions. Next to morphological and chemical characterization with the help of light optical and scanning electron microscopy, FactSageTM simulation and in-house mathematical models were used to describe phase transformation and the decarburization in the characteristic powder layers the-oretically. It was shown that the complex process of carbon combustion depends on multiple factors which must be considered when the mould powder is designed for the CC processes. The amount of carbon, its particle size and the application of the powder to the mould must follow strict rules to avoid related defects like carbon pick-up of the liquid steel. Finally, a better understanding of the carbon combustion and the melting process of mould powder was achieved. High potential for optimization and solutions of the application and composition of mould powder were shown, based on the inves-tigations, furthermore. The gained knowledge and findings provide high potential to optimize the usage of mould powders in continuous casting, avoid related defects and to supplement existing process models. Finally, an increase of the quality of the continuous casting process can be reached.