Experimental and computational study of nozzle electromagnetic stirring and its effects on solidification structure

Centreline shrinkage and segregation in continuously cast billets have an adverse effect on cast product quality. Nozzle electromagnetic stirring (N-EMS) is an effective method to refine the solidification structure of continuously cast billets and thereby improve the cast product quality. The effect of N-EMS on the solidification structure of continuously cast Sn-3(.)5Pb alloy has been investigated by means of experiments and numerical- analysis. The results show that, upon imposing N-EMS, crystal grains within the billets are refined and continuous casting can be conducted at a lower pouring temperature; the solidification structure of the resulting obtained billets is much finer than without N-EMS. The mechanism by which the solidification structure of the billets is improved is considered to be a change in the flow and temperature distribution of molten metal in the nozzle.