| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing technique of a cast slab for manufacturing an ultra-thick steel plate accompanying no lowering of the performance caused by negative segregation at the center part of the cast slab, in a continuous casting method for steel, performing rolling-reduction under state of non-solidifying. SOLUTION: In the continuous casting method for reducing the center segregation by rolling-reducing the cast slab containing non-solidified part using the rolling-reduction roll pair; regarding at least one component element contained for improving a mechanical property or a corrosion-resistant property, and according to the negative segregation degree of the component element as a value obtained by dividing the content of the component element at the thickness center part of the cast slab after rolling-reduction with the average content of the component element at the casting time, the steel is cast by increasing the content of the component element in the molten steel at the casting time more than the lower limit in the targeted content range in the product. The appropriate range of the increasing quantity of the content of the above component element in the molten steel is preferably decided based on the targeted range of the component element in the product, especially the lower limit value, and the range of the negative segregation degree at the thickness center part of the cast slab, especially the minimum value. COPYRIGHT: (C)2009,JPO&INPIT
|
