Numerical simulation of flow field in continuous casting slab mould under EMS conditions assisted with high-temperature quantitative velocity measurement

Abstract

In the present paper, the mathematical model of the flow field of the mould under the electromagnetic stirring (EMS) conditions is established and verified with high-temperature quantitative velocity measurement. Under the conditions of different casting speeds, argon gas flow rates, and immersion depths of the submerged entry nozzle (SEN), the simulation results are in quantitative agreement with the high-temperature measurement results. The flow velocities of molten steel show a central symmetric circulation on the mould surface under EMS due to the stronger electromagnetic force near the wide wall of the mould and the weaker electromagnetic force near the mould centre. With decreasing the casting speed and the immersion depth of SEN and increasing the argon gas flow rate, the flow field in the mould tends to form the single roll flow (SRF) pattern. With increasing the casting speed 20% and 40%, the measurement velocity of molten steel near 1/4 width is increased from −0.202 m/s to 0.111 m/s first and then to 0.276 m/s with the velocity towards the SEN as the positive value, and the flow pattern changes from SRF to unstable flow (UF) first and then to double roll flow (DRF). With increasing the argon gas flow rate by 100% and 200%, the flow pattern changes from DRF to UF first and then to SRF. With increasing the immersion depth by 10.7% and 21.4%, the flow pattern changes from UF to DRF.