Development of the hard reduction method in the No. 3 bloom caster at Kobe works, Kobe Steel

The center segregation of continuously cast blooms has to be improved, users demands being more and more severe concerning equiaxed crystal proliferation and filling observed in the conventional casting.In order to find a solution of this problem, several trials to prevent suction flow in the final solidification stage have been done recently.A solution to this problem has been developed consisting in a combination of CAE (Computer Aided Engineering) and experiment, and a hard reduction method with large diameter rolls : the flow is squeezed to offset the suction flow, the result being a remarkable improvement of the center segregation without any cracking on the solidification front.