Numerical Simulation and Composition Prediction of Steel Grade Transition for Five‐Strand Billet in the Full Continuous Casting Process

The steel grade transition is widely used to improve production efficiency and reduce production costs. However, there is a lack of accurate prediction method for the composition distribution and length of the mixed slab in steel plants. This paper adopts the numerical simulation method to establish mathematical models respectively for the five‐strand tundish and the casting slab in a steel plant. The mixing behavior of different steel grades in the tundish under various operating conditions was studied, the composition and length of the mixed casting slab under each working condition were predicted, and effective methods for reducing the mixed casting length were proposed. The results show that: the smaller the residual steel amount, the higher the dimensionless concentration of the new steel grade at the same time point, and the faster the steel grade updating rate; the influence of casting speed is not significant in the initial stage of mixed casting; the greater the tundish filling flow rate, the faster the steel grade updating rate, and after the completion of tundish filling, the changes in the concentration of the new steel grade under the three filling flow rates tend to be consistent gradually.