Study on the synergistic effect of electromagnetic stirring and mechanical reduction on the improvement of the internal homogeneity of high-carbon steel billet

Abstract

The synergistic effect of electromagnetic stirring (EMS) and mechanical reduction on the improvement of the internal homogeneity has been studied during the continuous casting of high-carbon steel billet. Plant trials were conducted with different parameters both for mold electromagnetic stirring (M-EMS) and final electromagnetic stirring (F-EMS), at the same casting condition and with a unified mechanical reduction process. As the stirring intensity of EMS increases, both the initiation and termination of columnar to equiaxed transition occur at an earlier timing. The results also indicate that, EMS could result in a decline trend for the compactness of the casting billet to a certain extent, especially in the pure equiaxed crystal zone at the core part of the billet. Under the proper intensity setting of M-EMS and F-EMS, the crack susceptibility of the high-carbon steel billet was markedly decreased by enlarging the mixed crystal zone, which is not arrayed with distinct directionality while featured with a relatively high compactness. The effect of EMS on the solidification behavior, and therefore on the crack susceptibility of the high-carbon steel billet was further explained with the numerical simulation. Consequently, a superior inner quality of high-carbon steel billet was successfully achieved with the effective synergy of EMS and mechanical reduction.