Measurement and calculation of magnetic flux density generated by the second cooling zone electromagnetic stirring (S-EMS) of a slab continuous casting strand

In the current study, a measurement of the magnetic flux density in the second cooling zone was performed for a 1250 mm width and 200 mm thickness slab continuous casting strand generated by the electromagnetic stirring with varied current intensity and frequency. From the narrow face to the width center of the slab, the magnetic flux density showed a increased, decreased, increased to a peak, and finally decreased trend. The magnetic flux density was decreased from the wide side to the thickness center of the slab, while an increase occurred from the model top to the stirrer center along the casting direction. To broaden the measurement range of the electromagnetic stirring parameters, the electromagnetic field in the strand and stirrer was calculated based on the finite element method, and the current input was achieved using the node loading approach. The effect of the mesh density on the calculation accuracy was investigated, and it was found that the 20 mm cell size in the strand region and the 10 mm cell size in the coil conductor and the iron core were enough to achieve a good agreement between the calculation and measurement. The empirical equations, B x = 0.165. f 0.63 . I −0.57 .(–6870. x 4 –9700. x 3 –4260. x 2 –495. x + 90), B y = 0.167. f −0.5 . I 0.45 . (4272. y 2 + 0.2733. y + 101.4), and B z = 0.1724. f −0.5 . I 0.45 .(0.0191.exp(24.16. z − 16.12. z 2 ) + 2.3) were derived to estimate the local magnetic flux density based on measured values across the width of the slab and calculated values along the casting direction under diverse operational conditions. These equations hold practical significance in elucidating the spatial distribution of magnetic flux density within the strand region in the second cooling zone.