| 摘要 |
PURPOSE:To maintain the round sectional shape of a round billet by forming a roll having an arc-shaped caliber in such a way that the curvature of the caliber at both ends in the axial direction of said roll is made larger than the caliber in the central part in the axial direction of the roll. CONSTITUTION:The curvature R' of the caliber at both ends of a pinch roll 2 having an arc-shaped caliber in the axial direction of said roll is made larger than the curvature R of the caliber in the central part in the axial direction of the roll. If a round billet 1 is drawn by such roll 2, the top and bottom surfaces of the billet 1 are rolled down by the roll 2 in the same way as in the prior part but the flattening of the billet by the horizontal part of the roll 2 is obviated. The billet 1 is thus formed to have a round sectional shape. |
