Abstract: During the continuous casting of molten steel, issues such as nozzle clogging, equipment failures, or insufficient steel supply may necessitate blocking flow or fewer strands casting operations in the tundish. Taking a certain steel plant's four-strand T-shaped billet tundish as the research object, a combination of physical simulation and numerical simulation was used to analyze variations in flow field, temperature distribution, and inclusion removal efficiency before and after blockage. Through systematic analysis, an optimized blockage strategy tailored to this tundish was identified, along with measures to enhance flow consistency post-clogging by increasing casting speed. The results demonstrate that blockage operations induce significant alterations in molten steel flow dynamics, characterized by a decline in average temperature within the casting zone and compromised flow uniformity. Notably, blocking the central nozzle exhibits a lesser impact on the flow field compared to blocking side nozzles. Under this condition, the tundish exhibits a dead zone proportion of 15%, a maximum temperature difference of 3 ℃ in the casting zone, and improved removal rates for inclusions across all particle sizes relative to normal casting operations. Furthermore, elevating the casting speed on the blocked side accelerates steel flow, reducing dead zone proportion, narrowing the standard deviation of stagnation time, and promoting more uniform temperature distribution. This research offers actionable insights for optimizing blockage/reduced-flow operations in similar four-strand T-shaped tundishes.

Key words: tundish, blocking flow, increase of casting speed, flow field, temperature field, inclusions