Numerical simulation of macrosegregation in continuously cast slab with application of S-EMS and MR

Abstract

A 3D numerical model was built to investigate the transport phenomena in slab continuous casting process to investigate the influence of strand electromagnetic stirring (S-EMS) combined with mechanical reduction (MR) on macrosegregation in continuously cast slab. The model was validated by measured strand surface temperature and magnetic induction intensity. The results show that the S-EMS with two pairs of electromagnetic stirring rollers in the opposite direction significantly affects the crater end profile and centerline carbon segregation in slab. The maximum solidification end position difference along the crater end profile of slab ΔL reduced from 0.82 m to 0.52 m, and the centerline carbon segregation is improved by the weak S-EMS, when the current intensity increases from 0 to 250 A. But, the maximum solidification end position difference along the crater end profile of slab ΔL increases from 0.52 m to 1.05 m, the carbon segregation at the 1/4 centerline length position near the right narrow side of slab deteriorates when the current intensity increases from 250 to 350 A. With the combined application of MR near the crater end of continuously cast slab, the solidification delay phenomenon caused by the S-EMS can be significantly improved. But, the solidification delayed cannot be suppressed with current intensity higher than 250A. Therefore, the harmonious application of weak stirring of S-EMS with current intensity of 250A and MR with reduction amount of 4 mm just before the crater end of slab is most benefit for the centerline carbon segregation improvement in continuously cast slab.