The adjustment of mould powder is crucial for a stable continuous casting (CC) process. A comprehensive study was conducted to investigate the melting behavior of mould powder, focusing on carbon, which is vital for the melting process and the interaction between slag and liquid steel in the meniscus area. Newly-designed test setups were utilized to observe phase transformation and carbon combustion during melting, both in laboratory and industrial conditions. Morphological and chemical characterization was performed using light optical and scanning electron microscopy, alongside FactSageTM simulation and in-house mathematical models to theoretically describe phase transformation and decarburization in characteristic powder layers. The study revealed that the complex process of carbon combustion is influenced by multiple factors that must be considered in mould powder design for CC processes. Key aspects include the amount of carbon, its particle size, and the application method, all of which must adhere to strict guidelines to prevent defects like carbon pick-up in liquid steel. The findings enhance the understanding of carbon combustion and the melting process of mould powder, revealing significant potential for optimizing its application and composition. This knowledge can improve the usage of mould powders in continuous casting, reduce related defects, and enhance existing process models, ultimately increasing the quality
