CAST SLAB AND MANUFACTURING METHOD FOR THE SAME

摘要

PURPOSE: A method of manufacturing continuous casting slab is provided to remove defects such as center segregation, since solute concentrated remaining molten steel is pushed toward a mold. CONSTITUTION: When continuous casting is performed by one or more segment rolls including an upper roll and a lower roll which face to each other in the thickness direction of slab(100), a section from 0.05-0.02 solid fraction to 0.3-0.6 solid fraction is pressed in the thickness direction of slab. The intrusion rate of a final roll among the segment rolls is 0.9-1.1. The intrusion gradient of the segment roll is 5-20 mm per 1m length of a casting direction. The intrusion amount of the segment roll is high to the downstream of the casting direction. The solute concentrated remaining molten steel flows backward, so the center of the slab has sub-segregation.