| 摘要 |
PURPOSE:To easily assure the diameter size and depth size of dimples to be worked by combining plural laser beams to constitute unit patterns at the time of forming the dimples on the cooling drum for casting ingots which is formed with the dimples on the surface by irradiation with laser beams. CONSTITUTION:This cooling drum is formed with the respective unit Patterns 2, each of which consists of one or laser processing traces gathered to each other, uniformly over the entire peripheral surface of the cooling drum. The size 3 in the longitudinal direction in the apertures of the unit patterns is >=80mum and <=500mum and the depth 4 of the unit patterns is >=70mum. |
