Process and device for influencing a profile of a rolled strip

A method for influencing quality parameters of rolled strips in a roll stand having rolls, comprising the steps of:

• controlling at least one of a camber of the rolls and a surface geometry of the rolls in a longitudinal direction of the rolls by thermally modifying a temperature of one of the rolls and surfaces of the rolls in the longitudinal direction;
• when a required change in the camber exceeds a possible change in the camber, determining a difference between the required change and the possible change;
• distributing the difference among a predetermined number of the rolled strips to minimize a deviation of the required change in the camber and of the possible change in the camber for the rolled strips;
• determining a quantity of a coolant;
• and
• applying a pattern of the coolant to the rolls as a function of the properties of the predetermined number of rolled strips especially at least one of:
• a load time of the roll stand,
• a pause time between two of the rolled strips,
• a roll-separating force, and
• a temperature of the strip
• wherein the pattern of the coolant is applied to the rolls using a roll model, the roll model maintaining a correlation between the quantity of the coolant and the pattern of the coolant to be applied to the rolls and further quality parameters of the rolled strips,
• wherein the roll model includes a rolled strip deformation model and an inverse thermal roll model,
• wherein the rolled strip deformation model correlates between an ideal roll camber and further quality parameters as a function of roll stand parameters and further rolled strip parameters, and
• wherein the inverse thermal roll model correlates between a command variable for cooling the rolls and the camber of the rolls as a function of the roll stand parameters and the rolled strip parameters.

A method of using a roll stand having axially extending rolls to control the flatness of a rolled strip by thermally controlling the camber of the rolls having strips, comprising the steps of:

• determining a desired degree of the camber of the rolls;
• determining a necessary change to the thermally controlled camber of the rolls for achieving the desired degree;
• determining a possible change at which the thermally controlled camber of the rolls can be achieved;
• comparing a difference between the possible change in the camber with the necessary change in the camber via an application of a thermal fluid to the rolls;
• distributing the difference among a plurality of rolled strips;
• providing a tolerance range for the strips by predicting if the necessary change in the camber of at least preceding one of the strips, with respect to a subsequent one of the strips, has occurred;
• and
• deviating from an optimal change of the camber for an individual one of the strips if values of the camber of the individual one of the strips are within the tolerance range.