| 摘要 |
PURPOSE:To improve rolling efficiency and to prevent breakage trouble in the inside of a mill by heating, before rolling, a joining part of strips of different thicknesses and reducing the variation of rolling load at the joining part at the time of rolling while changing the thickness of strip. CONSTITUTION:A hot rolled strip S to be cold rolled is unwound from a coiler 1 placed at the inlet side to cut its front and rear ends by a shear 2. The strips are butt welded together by a welder 3, and the joined strip is sent to the inlet side of a cold tandem mill 5 through a loop car 4. A welded point detector 6 and a heating device 7 are arranged at the inlet side of the mill 5, and a detecting signal is sent to the device 7 when the welded point is detected by the detector 6. The device 7 decides the passing time of the welded point basing on the line speed and the distance from the detector 6 to heat only the welded point. The strip having the deformation resistance reduced by heating the welded point is rolled by the mill 5. |
