Effect of nozzle clogging on flow and inclusion transport in GCr15 steel casting process

Abstract

Nozzle clogging affects molten steel flow, inclusion transport and slab quality. In this paper, a numerical simulation model for the nozzle clogging and the effect of the relevant parameters on the nozzle clogging simulation is studied. The nozzle clogging impact on the flow, inclusion transport and the nozzle clogging formation process are studied. The numerical simulation of the flow in the mold and nozzle is verified by particle image velocimetry measurement of the mold. The obtained simulation results of the clogged nozzle are verified by industrial experiments. The nozzle clog growth rate increases when the higher inclusion magnification factor is used. However, the nozzle clogging simulation results show that a hole exists in the nozzle clog. The deviation between the nozzle clog thickness obtained by the simulation results and those obtained from the experiments increase when the inclusion magnification factor increases from 1 to 20. The increase of the random walk model parameter increases the randomness of the inclusion transport. It is beneficial to increase the homogeneous simulation results of the nozzle clog thickness. The nozzle clogs that are initially formed in the upper section of the nozzle and extend then to the nozzle port. The nozzle clogs change the inner shape of the nozzle and result in the jet stream disperse, and the impact depth of the jet stream decreases when the solution time increases. The solid shell captures more inclusions, and the solid shell cleanliness decreases when the solution time increases.