| 摘要 |
The main purpose of the present invention is to provide a continuous casting method for a cast slab, which satisfies the reduction of center segregation and center porosity and the suppression of surface cracks and inner cracks in the cast slab using a flat roll. The present invention is a continuous casting method for a cast slab, comprising: a step for forming a pair of parallel surfaces in a cast slab having a circular cross section and an unsolidified region therein by reducing the cast slab by cylindrical horizontal rolls; and a step for forming a pair of parallel surfaces perpendicular to the pair of parallel surfaces in the cast slab by reducing the completely solidified cast slab alternately by a roll pair of cylindrical horizontal rolls and a roll pair of cylindrical vertical rolls, wherein in the former step, the reduction rate of the cast slab by each of the roll pairs is more than 0.5% but less than or equal to 3%, and the ratio of the width of the unsolidified region in the cross section of the cast slab to the width of a contact portion between the cast slab and the rolls is 0-7.15, and in the latter step, the reduction rates of the cast slab by the horizontal rolls and the vertical rolls are 5.4-6.8%, respectively. |
