Abstract: A method is provided for controlling interstand tension by roll gap adjustment to reduce gage variations caused by unplanned rolling velocity changes wherein a signal proportional to the tension changes produced by deviations from the desired speed ratio of adjacent stands is used to modify the conventional tension error signal before the latter signal is used to control roll gap thereby discriminating between tension changes caused by mill stand or strip physical changes, which it corrects, and tension changes caused by unplanned speed disturbances, which it ignores instead of maintaining constant tension. The resulting system exhibits improved tolerance for imperfect stand speed control.

Abstract: A method for controlling metal strip thickness in a multi-stand rolling mill is provided which employs feed forward control to adjust the main drive armature current at the upstream mill stand when strip thickness data arrives at the downstream mill stand, establishes a control signal representing the desired speed of the first stand as a function of the second stand's measured speed, the strip thickness measurements, and the scheduled speeds of the first and second stands, develops an armature current reference modifier which is added to the current reference developed by the conventional speed regulator and thereby improves gage control by reducing the response time for upstream stand speed changes and by correcting upstream stand speed for unplanned changes in downstream stand speed.

Abstract: A method for controlling edge taper ("feather") in a rolled metal strip utilizes a rolling mill having at least one pair of opposed work rolls through which the strip is passed for thickness reduction. The method first provides that a target rolling pressure is established as a function of the desired maximum amount of edge taper. A target crown for the finished strip is then established and the final work roll crown which will produce the target crown at the target rolling pressure is determined. The work roll crown is then adjusted to the final work roll crown for making the final pass of the strip through the work rolls.

Abstract: In a metal rolling mill of the type employing automatic gage control (AGC) to control the gap between the rolls utilized to reduce the thickness or gage of a workpiece passed between the rolls, there is provided a method for compensating for roll irregularities (e.g., eccentricity and ovalness). The method provides for developing signals proportional to the roll separation force and the roll rotational speed and isolating from the force signal those cyclic components which have a frequency which is an integral multiple of the roll rotational speed. The values of these cyclic components are then multiplied by a factor greater than unity and the resulting product is subtracted from the original force signal to thus develop a modified force signal which is utilized to control the AGC and hence the roll gap to thus compensate for roll irregularities.

Abstract: A rolling mill stand which includes roller elements for reducing the thickness of a workpiece which is passed therebetween further includes an adjusting mechanism for adjusting the gap between the roller elements and a sensor for sensing the roll separation force occasioned by passing the workpiece between the roll elements. The stand also includes a sensor for sensing the roller elements position and an automatic gage control device for controlling the gap adjustment mechanism as a function of the roll separation force. Associated with the rolling mill stand is a method of compensating for friction forces within the rolling mill stand occuring as a result of movement of the roller elements so as to improve the accuracy and stability of the automatic gage control.

Abstract: A method for controlling, in a reheat furnace of the type having a heat zone through which metal work pieces are moved over support skids and a soak zone in which slab temperature differentials are reduced, the variations in deformation resistance of the workpiece due to temperature gradients produced by the skids. This method first provides for establishing, for the furnace and the workpiece to be rolled, an initial skid mark characteristic expressing, at the time the workpiece leaves the support skids and enters the soak zone, the ratio of the deformation resistance of the workpiece in a region immediately contiguous the skids to the deformation resistance of the workpiece in a second region which is located approximately mid-way between adjacent skids. A skid mark decay characteristic defining the decay of the skid mark characteristic as a function of time elapsed after the workpiece has left the skids is then established.

Abstract: A method for controlling the temperature of a workpiece in a hot strip mill includes calculating temperature changes of the strip at each mill stand location by determining changes in workpiece deformation resistance and correlating the changes in deformation resistance to changes in temperature. Error corrections are made for changes in rolling speed. The calculated temperature change at each mill stand is used to control water sprays positioned adjacent the mill stands. A temperature sensor is placed downstream of the last mill stand to act as a check on the desired delivery temperature of the workpiece. Temperature discrepancies from the temperature sensor are fed upstream to modify temperature corrections.

Abstract: The flatness of metal strip being rolled in a hot strip mill is improved by applying higher than normal interstand tensions with maximum permissible tensions being based upon preestablished maximum allowable width reductions due to interstand tensions. The relationships between interstand tension and interstand plastic deformation are predetermined functions of strip material properties, strip temperature, and assumed tensile stress distribution across the strip width.

Abstract: A method and apparatus for correcting camber occurring during the rolling of a flat metal workpiece employs individual end adjustment of the work roll gap in response to the amount of camber detected.

Abstract: A method of controlling the shape of a workpiece in a rolling mill through the control of workpiece crown as the workpiece is being rolled includes the calculation of the roll-separating force required on each reducing pass as a function of roll elasticity, diameter and crown and workpiece resistance to deformation, width, entry crown and target crown.

Abstract: A method and apparatus for determining the initial opening of a pair of opposed work rolls utilized to reduce the thickness of a metal workpiece provides that selected readings of the roll separation force occasioned by passage of the workpiece through the rolls on a next preceding pass are utilized to determine the initial roll opening setting for the next pass of the workpiece between the rolls. The readings selected differ in accordance with a determination of whether or not the next pass is to employ automatic gage control.