| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sufficient internal property improving effect without any complicated device constitution. SOLUTION: In the continuous casting method for steel, the steel is continuously cast by controlling the rolling draft and the draft driving force for each reduction roll pairs or for each segment having a plurality of reduction roll pairs when performing the reduction of a slab in the thickness direction by using a plurality of reduction roll pairs on the upstream or downstream side of a crater end at which solidification inside the slab is completed. When reducing the slab 2, the slab 2 is reduced so that the reduction of the slab 2 by each reduction roll 4 pairs or each segments 1a, 1b is firstly reaches the target value. Then, the pressure propulsive value applied to each reduction roll 4 pairs or each segments 1a, 1b is controlled to be a mean value of the recorded reduction driving force of a charge in which the examination pass rate calculated from the result of the ultrasonic flaw inspection of a billet manufactured from a bloom cast by molten steel of the same composition in the past in a downstream process. Generation of center segregation or porosity can be effectively prevented, and slab of excellent internal properties can be obtained. COPYRIGHT: (C)2009,JPO&INPIT
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