| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method which can preventγ-grain-boundary cracks on the surface layer of a cast billet without causing bending of the cast billet, theγ-grain-boundary cracks being easily caused at a brittle temperature range below A<SB>3</SB>transformation temperature. SOLUTION: In the continuous casting method of a cast billet using a continuous casting machine having a correcting portion, a secondary cooling of the cast billet is carried out from the position just below the outlet of a casting mold in such a manner that the cooling speed is within the range from 5 to 10°C/s or less during the period in which the temperature of the portion at a depth of 5 mm from the surface of the cast billet drops from the A<SB>3</SB>transformation temperature to 800°C or lower. Then, the temperature of the portion at a depth of 5 mm from the surface of the cast billet is once returned to 950°C or higher until the cast billet is corrected. After that, the cast billet is corrected. COPYRIGHT: (C)2008,JPO&INPIT
|
