Segregation Control and Dendritic Structure Improvement of Steel Plate Hot Rolled Commercial Steel by Electromagnetic Swirling Flow

The mitigation of segregation within the slab is crucial for enhancing product quality. Controlled regulation of the flow and thermal fields in the mold facilitates precise adjustment of dendrite arm spacing, thereby suppressing segregation mechanisms. This study investigates the mechanisms by which the electromagnetic swirling flow in the nozzle (EMSFN) mitigates segregation in steel metallurgy. The segregation indices of solute elements in slabs are systematically compared under conditions with and without EMSFN application. A statistical analysis of dendrite arm spacing across slab regions establishes the correlation between dendritic microstructure refinement and segregation severity. Under EMSFN operation, the average primary dendrite arm spacing is reduced from 664.13 to 532.99 μm, while the secondary dendrite arm spacing decreases by 24.15% relative to without EMSFN conditions. The migration of solute elements toward the slab center is suppressed, resulting in a 45.98% reduction in the width of the centerline segregation zone. The industrial implementation of EMSFN is demonstrated to be critical for homogenizing solute distribution, enhancing solidification efficiency, refining solidification structure morphology, and enabling the production of high‐quality steel products.