CONTINUOUS CASTING METHOD FOR CASTING FOR EXTRA THICK STEEL SHEET

摘要

A primary object of the present invention is to provide a method for continuous casting with which slabs for heavy gauge steel plate in which porosities remaining about their centers in the thickness direction are extremely decreased can be manufactured. In the present invention, when a slab that is used as a material for manufacturing heavy gauge steel plate by hot-rolling is continuously cast, two pairs of reduction rolls 7 that are arranged separately from each other with an interval between the pairs in a range from 3 m to 7 m, between which a support roll 6 is arranged, are used, reduction is carried out on a slab 8 by 3 to 15 mm with the reduction rolls 7 at the first stage under the condition where the slab includes an unsolidified portion with the solid-phase ratio of the central part of the slab in the thickness direction in a range from 0.8 to less than 1, and reduction is further carried out on the slab with the reduction rolls 7 at the second stage under the condition where the slab is completely solidified.