Tundish Flux Drainage-Induced In-Mold Performance Evolution of Mold Flux

The evolution of mold flux performance in the mold induced by tundish flux drainage is important for understanding mold flux failure, yet few studies address this issue. This study systematically investigates and elucidates the relationship between tundish flux drainage and mold flux performance in the mold. As the drainage ratio increases from 0 to 1.25, the mold flux viscosity at 1300 °C rises from 0.4 to above 1.0 Pa·s, impairing lubrication. Meanwhile, the average heat flux density decreases from 0.973 to 0.682 MW/m2, resulting in a thinner initial solidified shell. The crystallization temperature increases from 994 to 1340 °C, reducing the liquid slag film thickness. The primary crystalline phase changes from Ca4Si2F2O7 to Ca2Al2SiO7 and Na2CaAl4O8, both of which have high melting temperatures. These changes in lubrication, heat transfer, and crystallization behavior significantly increase the frictional force acting on the initial solidified shell and reduce its resistance to tearing, thereby promoting breakouts.