| 摘要 |
PURPOSE:To adjust uniformly the transverse direction of a plated surface and to obtain a plated steel sheet having particularly good paintability by passing the hot dipped steel sheet between upper and lower variable crown rolls provided with pressurizing chambers to be acted with oil pressure. CONSTITUTION:An upper roll 3 and a lower roll 3 consituting variable crown rolls are respectively disposed in such a way that the lower side of the former forms a pressurizing chamber 8 and the upper side of the latter forms a pressurizing chamber 8. When a steel sheet 1 plated thereon with Zn, Al or the like is passed through said rolls, the skin pass rolls deform like solid lines 4' but if oil pressure is preliminarily generated in the chambers 8 of the rolls 3, the body parts of the rolls are corrected like dotted lines 4''. The plated surface of the sheet 1 is eventually uniformly rolled down in the transverse direction. The plated steel sheets of various different shapes and materials can thus be pressed uniformly in the transverse direction of the plated surface and therefore the spangle and residual dross on the plated surface are crushed uniformly with one time of skin pass and the surface of the paint coated film is made beautiful in subsequent painting. |
