New insight into relationship between casting speed and inclusion removal in the tundish

The tundish is the last refractory metallurgical reactor during the continuous casting pro-cess, and the fluid flow in the tundish is one of the key factors to control inclusion collision -coalescence and its removal. Thus, numerical method is applied to obtain the flow field, the RTD curve and the inclusion field. Numerical results showed that the predicted RTD curve and the inclusion number density agree well with the experimental data. In the case of different fluid velocity at tundish inlet, the volume fraction of plug zone, dead zone and well-mixed zone keep unchanged, but the dimensionless tundish inclusion volume con-centration, the dimensionless tundish inclusion radius and the inclusion removal ratio have the exponential relation to the fluid velocity at tundish inlet. Further, there is maximum inclusion removal rate for the specific tundish. Another interesting phenomenon is about the inclusion behavior and the characteristic time of the RTD curve. The inclusion removal ratio and the dimensionless tundish inclusion radius have the linear relation to the mini-mum residence time, the peak concentration time and the average residence time. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The tundish is the last refractory metallurgical reactor during the continuous casting process, and the fluid flow in the tundish is crucial for controlling inclusion collision and removal. Numerical simulation is used to investigate the flow field, RTD curve, and inclusion field. The results showed good agreement between the predicted RTD curve and the experimental data. Furthermore, it was found that the fluid velocity at the tundish inlet exponentially influences the dimensionless tundish inclusion volume concentration, radius, and inclusion removal ratio.