Comparison of the Flow Field in the Slab Continuous Casting Mold Between the Two- and Three-Hole Nozzles with High Temperature Quantitative Velocity Measurement and Numerical Simulation

The flow field, fluctuation of interface between steel and slag, distribution and capture of argon gas and solidified shell thickness in molds with different nozzles with two or three holes are studied with high-temperature quantitative velocity measurement and numerical simulation. The simulated results of surface velocities are in good agreement with the high temperature measurement results under different argon gas flow rates in the mold with the two- and three-hole nozzles. Compared to the mold with the three-hole nozzle, in the mold with the two-hole nozzle, the surface velocities of molten steel, fluctuation of interface between steel and slag, and inclination angles of jet flow of molten steel are larger, while the capture ratio of argon gas bubbles and solidified shell thickness are smaller under the same continuous casting parameters. When the argon gas flow rate is increased from 4 L/min to 8 L/min, the inclination angle of jet flow and capture ratio of argon gas decrease from 21.8° to 16.7° and increase from 0.12% to 0.27% in the mold with the two-hole nozzle. Those decrease from 20.5° to 11.3° and increase from 0.44% to 0.49% in the mold with the three-hole nozzle, respectively.