Mathematical And Physical Simulation Of Liquid Steel Flow In A Mold For Thin Slab Continuous Casting

High casting speed is one of the primary characteristics of thin slab continuous casting. It is significant to determine the appropriate technological parameters of continuous casting and the structural parameters of submerged entry nozzle for casting production well, because of the effects of improving the flow behavior of the liquid steel, reducing the probability of the slag entrapment and the surface bareness, promoting the floating and removal of the inclusions and improving the uniformity of the solidified shell. It is crucial to study the flow behavior of the liquid steel and its influencing factors for ensuring the continuous casting well and improving the quality of thin slab.According to the flexible thin slab casting mold in a certain steelmaking plant, by means of mathematical and physical simulation, the effects of the technological parameters of CC and the structural parameters of SEN on the flow behavior of the liquid steel and slag entrapment in the mold were studied in the present work. On the basis of the discussion, the parameters were analyzed and optimized. Under the experimental conditions, some results are as follows.(1) The impact depth of liquid steel in the mold increases with the immersion depth of SEN enhancing. The effect of the type of the SEN on the impact depth is very great. The impact depth of nozzle A is maximal, and that of the nozzle C is minimal.(2) The levels of surface bareness and slag entrapment increase gradually with the casting speed enhancing, while those decrease gradually with the immersion depth of SEN enhancing. The locations of the surface bareness and slag entrapment change with the different types of SEN.(3) The surface fluctuation and the probability of slag entrapment are maximal when the nozzle A is used, and those are minimal when the nozzle C is used. The effect on the inclusion removal of nozzle B is the best, and that of the nozzle C is the worst.(4) The turbulent kinetic energy and the flow velocity of the surface liquid steel in the mold increase gradually with the casting speed enhancing. But the distribution positions of the maximal surface turbulence kinetic energy and the maximal surface flow velocity do not change.(5) The turbulent kinetic energy and the flow velocity of the surface liquid steel in the mold decrease gradually with the immersion depth of SEN enhancing. And the distribution positions of the maximal surface turbulent kinetic energy and the maximal surface flow velocity move to the narrow face slightly.(6) When the nozzle A and the nozzle B are used, there are four spiral vortexes in the mold, whereas only two spiral vortexes when nozzle C is used. The locations of the spiral vortexes become deeper with the immersion depth of SEN enhancing.(7) For theâ… mold, the nozzle A should be adopted. When the casting speed is from 3.5m/min to 4.0m/min, the optimal immersion depth of SEN is from 175mm to 195mm. For theâ…¡mold, the nozzle B should be adopted. When the casting speed is from 3.5m/min to 4.0m/min, the optimal immersion depth of SEN is from 145mm to 195mm. For theâ…¢andâ…£mold, the nozzle C should be adopted. When the casting speed is from 3.5m/min to 4.0m/min, the optimal immersion depth of SEN is from 145mm to 195mm.