| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of breakout by preventing the formation of a gap between a step part of a ring-shaped recessed part and a solidified shell. SOLUTION: Recessed rolls 101,102 have the step parts 101a, 101b, 102a and 102b at both end parts and also are formed with the ring-shaped recessed parts 107a, 107b, 109a and 109b near the step parts (step part rising parts 131a, 131b, 132a and 132b). Since the solidified shells 111 and 112 solidified by being cooled with the roll surfaces, enter the ring-shaped recessed parts 107a, 107b, 109a and 109b and get stuck thereon, even if solidified shells 111 and 112 tend to thermally shrink along a roll axial direction, this shrinkage is prevented. As a result, the formation of the gap near the step part is prevented, the heat-exhausting even near the step parts is promoted, the growth of the solidified shell at the position is progressed and the occurrence of the breakout can be prevented. COPYRIGHT: (C)2006,JPO&NCIPI
|
