A New Criterion for Optimization the Intermittently Reversing Direction Electromagnetic Stirring in Round Strands Continuous Casting

Liquid metal flow behavior in round strands continuous casting under intermittently reversing direction electromagnetic stirring was measured by ultrasonic Doppler velocity-meter in a physical simulation system in order to investigate the effects of time interval () of periodically reversed magnetic field on the spatial and temporal flow. The results show that under electromagnetic stirring with direction reserved magnetic field, theres a periodically change of the metal flow velocity and rotation direction with the periodically direction changing of the magnetic field. From both the experimental and mathematical model calculation results, it is found that when is nearly equal to the time required for the metal flow speeding to the maximum velocity from still and decreases to zero again, there is a critical value of the rate of dynamic pressure, which means the wash effect of the liquid metal flow. On this point, rate of dynamic pressure was proposed to be a criterion for optimization the processing of electromagnetic stirring.