PURPOSE: To remove the difference of brightness between a front and a rear side and to roll an extra-thin sheet by using rolls higher in elastic force or smaller in diameter than working rolls used in a 1st rolling step as working rolls used in a 2nd rolling step.
CONSTITUTION: Two rolling materials 1, 2 are wound respectively independently round reels 7, 8 and 9, 10 and superposed and rolled by working rolls 15, 16 small in diameter supported by lack-up rolls 5, 6 through intermediate rolls 17, 18. Rolling advances and the material 2 only is bitten and released once at a stage one pass before the final pass. Regarding the material 1, an ordinary rolling which is not a pack rolling is performed successively but, simultaneously, the operating rolls of the rolling mill have been changed with the working rolls 15, 16 small in diameter and the intermediate rolls 17, 18 supporting them. Consequently, at least one pass rolling is carried out by the working rolls 15, 16 small in diameter and the difference of brightness between the front and the rear side is dissolved.
HIRAMA YUKIO
SATO KOJI
