| 摘要 |
PURPOSE:To squash out perfectly the central pores existing in the inside of a billet by subjecting the billet to the rolling reduction specified in shape ratio at the time when the billet has a prescribed temperature difference between its surface and central part just after being perfectly solidified. CONSTITUTION:In a continuous casting process; a billet just after solidified, having the >=200 deg.C temperature difference between its surface and central part, is subjected to rolling reduction at a >=0.5 shape ratio by a press or rolls, etc.; where, the shape ratio is the effective contact length (mm) in the longitudinal direction of billet/the thickness (mm) of billet. By this rolling reduction, the compression in the longitudinal direction of billet, required for perfectly extinguishing the central pores in the billet, is produced. This rolling reduction is applied only in the thickness direction of billet, and the rolling reduction in the width direction is not always required. |
