Development of control technology and clogging mechanism for tundish nozzle in continuous casting

The clogging of tundish nozzle in continuous casting can seriously affect the practical operation, resulting in slag entrapment and slab quality deterioration. The solution to the nozzle clogging is of importantance to ensure the production stability and the high strand quality. Based on the previous research results, the mechanisms of nozzle clogging were reviewed at different conditions of the casting steel grade, deoxidation and refining of the liquid steel and so on. The effects of different factors on the nozzle clogging were summarized, which include the inclusion formation in the molten steel, the inclusion migration to the inner surface of nozzle and the adhesion and deposition on the inner surface of nozzle. The features and deficiencies of various control technology for the prevention of nozzle clogging were analyzed. Then, the research directions of the control theory and technology for the prevention of nozzle clogging were put forward.