Method for the production of flat metal products, in particular coils of strip, in endless and/or semi-endless mode, in which a metal product is continuously fed to a rolling mill consisting overall of at least 4 stands. The rolling stands are, in sequence, roughing stands, and finishing stands. It is provided to perform a flying gauge change of the metal product exiting from the rolling mill.

A method for operating a roll stand for the stepped rolling of metal strip is described. The metal strip is initially fed into a roll stand on the infeed side, where it is step-rolled. This creates a leading and a trailing section of the metal strip, each with different thicknesses. After the roll stand, the step-rolled metal strip initially passes through an outfeed-side strip accumulator before it is wound into a coil by an upcoiler. The outfeed-side reel is controlled to a constant strip tension. To keep the outfeed-side strip tension sufficiently constant even in the case of rapid changes in the size of the roll gap and the resulting rapid changes in thickness in the rolled metal strip the control of the strip tension with the aid of the upcoiler is supplemented by a position control for a roller unit in the outfeed-side strip accumulator.

An apparatus for controlling a strip tension during flexible rolling of metal strip comprises a roll arrangement with at least one dancer roll, the position of said dancer roll being adjustable for controlling the strip tension of the metal strip, at least one hydraulic drive coupled to the dancer roll for adjusting the dancer roll, a hydraulic tank for hydraulic fluid, which is fluidly connected to the hydraulic drive via a hydraulic supply line, a controllable valve arrangement between the hydraulic tank and the hydraulic drive for controlling the hydraulic drive, a hydraulic pump with which the hydraulic drive is supplied with hydraulic fluid from the hydraulic tank, and at least one hydraulic pressure accumulator for temporarily storing hydraulic fluid previously delivered by the hydraulic pump, the hydraulic pressure accumulator being arranged between the hydraulic pump and the valve arrangement, wherein a pressure sensor is arranged in the hydraulic drive for determining the hydraulic pressure.

A rolling system, particularly a cold-rolling system for cold-rolling a metal strip (2): having at least one cold-rolling stand (1) an unwinding device (3) upstream of the cold-rolling stand (1), a unit (10) connected between the unwinding device (3) and the cold-rolling stand (1), including at least three rolls (6, 7, 8) each rotationally driven about a rotational axis (6A, 7A, 8A). Each roll (6, 7, 8) can be adjusted individually or together in the direction of the respective rotational axis (6A, 7A, 8A) and in a direction transverse to the rotational axis (6A, 7A, 8A) by a driving and adjusting device (11).

A first steel strip and a second steel strip (7) are rolled in succession in at least one roll stand (1) of a cold rolling mill. A rolling pause, in which no steel strip is rolled, is provided between the rolling of the first and the second steel strip (7). The first steel strip s fed over a first path starting from a first pay-off reel (2), and the second steel strip (7) is fed over a second path starting from the first pay-off reel (2), or from a second pay-off reel different from the first pay-off reel (2). The first steel strip is not heated as it is fed to the rolling mill (1), whereas, by contrast, the second steel strip (7) is heated. The second path is longer than the first path.

In a normal operation of a roll stand (e.g. 4) of a roll train, working rolls (10) of the roll stand (4) are adjusted to a roll gap (s4) by adjusting a control element position (p4) of a control element (14) of the roll stand (4), such that the working rolls (10) roll the metal band (5). To determine the control element position (p4) to be adjusted, a calibration value (sC4) of the respective roll stand (4), further status parameters (P4) of the roll stand (4) and a target roll gap (s4*) are specified to a model (15) of the roll stand (4). The model (15) determines the control element position (p4) to be adjusted therefrom. In the calibration operation, a control element position (p4) is initially adjusted such that the metal band (5) passes through the roll stand (4) without being rolled. The control element position (p4) is varied such that the working rolls (10) roll the metal band (5). A thickness (d) of the metal band (5) is detected by a downstream thickness-measuring device (9). The thickness (d), further status parameters (P4) and the control element position (p4) are supplied to the model (15), which determines the calibration value (sC4) of the respective roll stand (4) therefrom. Subsequently, normal operation is resumed and the previously determined calibration value (sC4) is used to determine control element positions (p4) to be adjusted as the calibration value (sC4) of the respective roll stand (4).

A device for laterally guiding a metal strip (1, 13) running over a loop lifter (4, 12) between two roll stands (2, 3, 8, 9) of a finishing train. The device includes at least one main member module (14) extending in a direction between the roll stands. The module has a guiding plane (15), and also supports a number of wear members (18, 19, 20), each with a wear surface (21, 22, 23). Those wear members can be turned to a number of rotational positions. At least two wear members (18, 19, 20) are respectively arranged between one of the roll stands (2, 3, 8, 9) and the loop lifter, wherein, seen in the direction of the loop lifter (4, 12), the surface area of the wear surface (21, 22, 23) of adjacent wear member bodies (18, 19, 20) increases. During the operation of the device, at least one of the wear members is rotated while the metal strip (1, 13) is running to expose another area of the wear surface to the side of the strip.

A device for laterally guiding a metal strip (1, 13) running over a loop lifter (4, 12) between two roll stands (2, 3, 8, 9) of a finishing train. The device includes at least one main member module (14) extending in a direction between the roll stands. The module has a guiding plane (15), and also supports a number of wear members (18, 19, 20), each with a wear surface (21, 22, 23). Those wear members can be turned to a number of rotational positions. At least two wear members (18, 19, 20) are respectively arranged between one of the roll stands (2, 3, 8, 9) and the loop lifter, wherein, seen in the direction of the loop lifter (4, 12), the surface area of the wear surface (21, 22, 23) of adjacent wear member bodies (18, 19, 20) increases. During the operation of the device, at least one of the wear members is rotated while the metal strip (1, 13) is running to expose another area of the wear surface to the side of the strip.

A device for laterally guiding a metal strip (1, 13) running over a loop lifter (4, 12) between two roll stands (2, 3, 8, 9) of a finishing train. The device includes at least one main member module (14) extending in a direction between the roll stands. The module has a guiding plane (15), and also supports a number of wear members (18, 19, 20), each with a wear surface (21, 22, 23). Those wear members can be turned to a number of rotational positions. At least two wear members (18, 19, 20) are respectively arranged between one of the roll stands (2, 3, 8, 9) and the loop lifter, wherein, seen in the direction of the loop lifter (4, 12), the surface area of the wear surface (21, 22, 23) of adjacent wear member bodies (18, 19, 20) increases. During the operation of the device, at least one of the wear members is rotated while the metal strip (1, 13) is running to expose another area of the wear surface to the side of the strip.

A first steel strip and a second steel strip (7) are rolled in succession in at least one roll stand (1) of a cold rolling mill. A rolling pause, in which no steel strip is rolled, is provided between the rolling of the first and the second steel strip (7). The first steel strip is fed over a first path starting from a first pay-off reel (2), and the second steel strip (7) is fed over a second path starting from the first pay-off reel (2), or from a second pay-off reel different from the first pay-off reel (2). The first steel strip is not heated as it is fed to the rolling mill (1), whereas, by contrast, the second steel strip (7) is heated. The second path is longer than the first path.