Applicability analysis of multiple electromagnetic stirring types in large-size round bloom continuous casting: A flow behavior-based study

A coupled criterion based on the Q-criterion and velocity was established in the present study to identify and quantify the stirring region and the functional characteristics of the rotational flow induced by electromagnetic stirring (EMS). Differences among various EMS types were analyzed in terms of their capabilities for flow-facilitating, solidification feeding, flow symmetry, and volumetric distribution. The results indicate that the single-coil spiral magnetic field stirring (SSMF) exhibits the best performance in flow-facilitating. The superimposed spiral magnetic field stirring (SMF) generates the largest feeding-promoting volume as well as the largest flow-hindering volume. The rotating magnetic field stirring (RMF) exhibits balanced performance in both flow-facilitating and feeding-promoting. Regarding flow symmetry, the SSMF yields a more uniform and symmetric flow structure, whereas the SMF causes noticeable deviation and asymmetry. In terms of velocity distribution, the traveling magnetic field stirring (TMF) provides the most uniform distribution, though with limited stirring intensity. Conversely, the SMF shows the poorest uniformity, but with the largest velocity, while the SSMF creates the largest high-velocity region, with a stronger scouring effect. Simulation results revealed that the SSMF offers greater advantages in feeding, and plant trials further verified the accuracy of this prediction at the final solidification.