| 摘要 |
PROBLEM TO BE SOLVED: To prolong a roll life and stabilize rolling by specifying dimension of a long hole arranged on a work roll surface and its total area ratio. SOLUTION: A long hole 4 is formed on the surface of a work roll for cold rolling extending in the roll axial direction with regularly arraying in the peripheral direction by radiating laser beam. A hole bottom 6 of the long hole 4 is flat, its depth (d) is set to a range of 3-40μm, the major diameter to 50-200μm, the major diameter to 200-600μm. An area ratio of hole working area to the total roll area is set to 2-30%. The long hole 4 can make microscopic friction coefficient larger because an edge length in the roll axial direction is longer than a round hole and a specified a friction coefficient as whole roll is secured in the case of a wider hole pitch, stable rolling can be executed. According to experiment, the wider hole pitch can extent a roll life. An axial direction pitch PA of about 300-1000μm and a peripheral direction pitch PC of about 300-1000μm are appropriate. |
