Abstract: A similar ratio of 1∶2 water model was used to do the orthogonal experiments for the flow control device in slab casting tundishes, to study the influence rules of height and position of lower dam on the flow field, and find the optimal flow control mode. Furthermore, the contrast test between the prototype and optimized tundish was carried out in the steel plant. The results show that retaining a reasonable position and height of lower dam have important influence on the fluid flow behavior of molten steel in the tundish. After lower dam in prototype tundish was moved 1 m toward the injection flow area (scheme No.B15), compared with the prototype tundish, average resident time of optimized tundish was increased of 14.3 %, dead area ratio was decreased of 10.58 %, stagnation time was increased of 11.8 %, and fluid flow state of molten steel in tundish was improved. Meanwhile, T.O mass fraction in tundish was decreased of 47.3 %, the amount of macro inclusions in slab was decreased of 62.3 %, the macro inclusions with size of more than 300 μm were hardly found in the slab, and the total oxygen content in the slab was controlled more stably after optimization, so the removal efficiency of the inclusions was improved obviously.

Key words: tundish, structural optimization, flow field, inclusions, molten steel, industrial tests