METHOD FOR PREVENTING SURFACE CRACK IN HOT-EDGING OF CONTINUOUSLY CAST SLAB

摘要

PROBLEM TO BE SOLVED: To prevent a crack defect on the surface of a cast slab at the time of hot-edging the continuously cast slab containing N and Al or Nb. ;SOLUTION: After cooling a part within 10 mm below the surface layer of a continuously cast slab to not higher than the Ar₁ and reheating it to 1000-1150°C, and by completing the hot-edging at not lower than the Ar₃, or after cooling the above part to not higher than Ar₁-50°C and reheating it to 1000-1150°C, and by executing the hot-edging, cracks due to precipitation of carbo-nitride and cracks due to film-shaped α in the above part are simultaneously prevented and edging is executed without generating cracks on the surface of the cast slab.;COPYRIGHT: (C)1999,JPO