To reduce centerline segregation generated in a center portion of a continuously-cast steel cast slab.
A steel cast slab is continuously-cast while the steel cast slab is subjected to rolling-reduction from at least when the solidus ratio of a thickness center portion of the cast slab is 0.3 till when it is 0.7 by using a continuous casting machine 1 provided with a soft rolling-reduction belt 14 for imparting the rolling-reduction force to a cast slab 10. In this case, the mean value B(mm) of the roll-to-roll bulging amount from when the solidus ratio of the thickness center portion of the cast slab is 0.3 till when it is 0.7 is obtained by the unsteady heat transfer solidification calculation, the rolling-reduction amount from when the solidus ratio of the thickness center portion of the cast slab is 0.3 till when it is 0.7 is measured, the effective rolling-reduction rate A(mm/min) from when the solidus ratio of the thickness center portion of the cast slab is 0.3 till when it is 0.7 is calculated based on the measured rolling-reduction amount, the ratio (A/B, unit: 1/min) of the effective rolling-reduction rate A obtained by the calculation to the mean value B is obtained for each cross section of the cast slab, and the casting condition is adjusted so that the obtained ratio (A/B) is ≥8.0.
MIKI YUJI
ARAMAKI NORICHIKA
| JP2009066652A | 2009-04-02 | |||
| JP2010158719A | 2010-07-22 | |||
| JPH0422552A | 1992-01-27 | |||
| JP2009233703A | 2009-10-15 | |||
| JP2011224583A | 2011-11-10 |
Kazuhiro Mori