Characteristics of solute segregation in continuous casting bloom with dynamic soft reduction and determination of soft reduction zone

Abstract

A mathematical model accounting for the discharge of solute enriched liquid from the mushy zone with soft reduction by one pair of pinch rolls was established, and the ratio of solute concentration in the mushy zone before and after soft reduction, named as solute segregation ratio, is proposed to describe the characteristics of solute segregation. The theoretical analysis of solute segregation ratio at different soft reduction positions shows that the start point of the soft reduction zone should not be greater than the minimum optimum soft reduction position and the end point of the soft reduction zone should not be less than the maximum optimum soft reduction position corresponding to minimum solute segregation ratio. The soft reduction industrial practices of steel YQ450NQR1 and steel 37Mn2 were carried out with the soft reduction parameters determined by the model, and results showed that the inner quality was improved.