Numerical model for the minimization of intermixed round bars in a four line continuous caster

The grade transition process in a four line round billets continuous easter was analyzed. A numerical model was developed to determine, quickly and ac curately, the length and location of intermixed steel in the bar. The model is based on "tank in series" or "volumes" mathematical models and was cali brated with physical water model measurements and full three-dimensional (3 -D) turbulent numerical calculations. Comparison of the model with measurem ents performed on intermixed steel bars is also presented. The good agreeme nt between these plant measurements and the numerical results validated the model. The model was implemented on PCs with a visual interface that allow ed the easy input and output of data, and the program is operated in a stee l shop. Finally, the code was employed to evaluate different strategies to fill the tundish during grade transitions. The "double dilution" process, w hich consists of filling the tundish in two steps, proved to be useful to r educe the amount of downgraded steel.