| 摘要 |
PURPOSE:To form a large step up to the threshold within the limitation of the stroke length of a hydraulic screw-down cylinder with a lessened decrease of yield and less influence on rolling rolls by subjecting the step region of a sheet material formed with an initial thickness difference to automatic sheet thickness control to expand the thickness difference in the next and subsequent passes. CONSTITUTION:The sheet material 2 formed by subjecting a sheet material 1 to the formation of the initial thickness difference (thin flat part 2a and thick flat part 2c) in the mid-way of finish rolling is obtd. The flat parts 2a, 2c are then subjected to an orginary thickness control (AGC) and the step region 2b to AGC to expand the rate of the thickness difference in the next and subsequent passes of the mid-way pass in which the initial thickness difference is formed to the material 2. The sheet material 3 having the expanded rate of the thickness difference is obtd. Such AGC is reiterated till the final pass. The different thickness sheet material which is the product is thus formed. |
