(p350) Improvement of inclusions cleanliness by control of tundish steel flow - experimental and numerical approaches.

摘要

In continuous casting of steels, the control of inclusions cleanliness is strongly linked to steel flow patterns in thetundish.In order to define potential steel flow improvements in the tundish of ASCO INDUSTRIES Hagondangesteelmaking shop, a cooperative work involving the CREAS (Ascometal Research Centre) and VESUVIUS wasundertaken. Within this project, experimental and numerical approaches were combined.Experiments were carried out in order to characterize the inclusions distribution and the temperature field in theindustrial tundish during casting. Then, a water model (1:3 scale) was built in order to simulate fluid flows. Dyeconcentration measurements were analyzed.A numerical model taking into account fluid flows, heat transfers and inclusions behaviour was developed usingFluent Workbench~R. The model was validated thanks to experimental results obtained with the water model andindustrial trials.The use of this model made it possible to evidence the effects on steel cleanliness of various process parameters(casting rate, surface insulation...) and various Turbostop~R designs. It was first highlighted that the behavior ofinclusions is strongly dependent on their size. Secondly, the great influence of the thermal insulation and the steelflow on the inclusions elimination was demonstrated. Finally, potential flow improvements in the tundish of theHagondange steel plant could be defined.