Refining of Solidification Structures of Continuously Cast Type 430 Stainless Steel Slabs by Electromagnetic Stirring

Refining of the solidification structure of Type 430 stainless steel by the electromagnetic stirring was studied. By the preliminary tests for small ingots, it was made clear that the following conditions must be satisfied for a preferably equiaxed solidification: 1) the formation of sufficient fragments of solidified steel which act as nuclei, and 2) the stability of nuclei in the molten pool. A pair of linear-motor type stirrers was set in the slab machine and Type 430 steels were treated by the electromagnetic stirring under various conditions of stirring powers, stirring modes and superheats of liquid steels. By controlling these conditions, the formation of equiaxed structure having the thickness more than 50% of slab was realized and the ridging of cold sheet was improved.