A casting of metal strip by continuous casting in a twin roll caster is provied. In a twin roll caster, molten metal is introduced between a pair of counter-rotated horizontal casting rolls that are cooled so that metal shells solidify on the moving roll surfaces. The twin roll caster is capable of continuously producing cast strip from molten steel through a sequence of ladles positioned on a turret. In casting thin strip by twin roll caster, the crown of the casting surfaces of the casting rolls varies during a casting campaign. The crown of the casting surfaces of the casting rolls in turn determines the strip thickness profile.

A metal strip is rolled in a roll stand and a control device for the roll stand determines, by means of a working cycle, a number of manipulated variables for flatness actuators of the roll stand and actuates them accordingly. The control device implements an optimizer, which provisionally sets the current correction values, and determines a totality of flatness values. Then, the optimizer minimizes the relationship by varying the current correction variables. When determining the current correction variables (s), the optimizer considers linear ancillary conditions, based at least in part on a vector having the ancillary conditions upheld by the current correction values and a vector having the ancillary conditions upheld by the difference of the current correction values relative to the correction values of the preceding working cycle. The control device determines the manipulated variables for the flatness actuators in consideration of the determined current correction variables.

A method for rolling a product to be rolled (3), wherein the product (3) is fed through a rolling gap (11) between two working rollers (9, 10) of a roll stand (1) and a cooling lubricant is introduced into a contact zone (15, 16), in which a contact surface (17, 18) of the product to be rolled (3) lies against a working roller (9, 10), in order to lubricate the contact zone (15, 16). Furthermore, a lubrication demand of the contact zone (15, 16) is determined in accordance with at least one process parameter of the rolling process and an additional lubricant is applied to the contact surface (17, 18) of the product to be rolled (3) before the rolling gap (11) at a specified application distance (D) if a cooling lubricant amount (C) presently introduced into the contact zone (15, 16) does not cover the lubrication demand. The application distance (D) is sized such that adhesion of the additional lubricant to the contact surface (17, 18) is increased and the lubricating effect in the contact zone (15, 16) is improved in comparison with application immediately before the rolling gap (11). In addition, the lubricant amount (C) introduced into the contact zone (15, 16) is reduced if additional lubricant is applied to the contact surface (17, 18).

A method for rolling a product to be rolled (3), wherein the product (3) is fed through a rolling gap (11) between two working rollers (9, 10) of a roll stand (1) and a cooling lubricant is introduced into a contact zone (15, 16), in which a contact surface (17, 18) of the product to be rolled (3) lies against a working roller (9, 10), in order to lubricate the contact zone (15, 16). Furthermore, a lubrication demand of the contact zone (15, 16) is determined in accordance with at least one process parameter of the rolling process and an additional lubricant is applied to the contact surface (17, 18) of the product to be rolled (3) before the rolling gap (11) at a specified application distance (D) if a cooling lubricant amount (C) presently introduced into the contact zone (15, 16) does not cover the lubrication demand. The application distance (D) is sized such that adhesion of the additional lubricant to the contact surface (17, 18) is increased and the lubricating effect in the contact zone (15, 16) is improved in comparison with application immediately before the rolling gap (11). In addition, the lubricant amount (C) introduced into the contact zone (15, 16) is reduced if additional lubricant is applied to the contact surface (17, 18).

A rolling mill exit side temperature control system includes the following features. A second valve control unit controls a valve opening of a second valve to cause a flow rate actual value detected by a flow rate detector to coincide with a flow rate target value. A remaining coolant discharging section controls a first valve to an open state and the second valve to a closed state by setting the flow rate target value to zero, before a material to be rolled reaches a rolling mill. A flow rate target value setting section sets the flow rate target value to a value corresponding to a target temperature of the material to be rolled on the entry side and the exit side of the rolling mill after the control by the remaining coolant discharging section.

A rolling mill exit side temperature control system includes the following features. A second valve control unit controls a valve opening of a second valve to cause a flow rate actual value detected by a flow rate detector to coincide with a flow rate target value. A remaining coolant discharging section controls a first valve to an open state and the second valve to a closed state by setting the flow rate target value to zero, before a material to be rolled reaches a rolling mill. A flow rate target value setting section sets the flow rate target value to a value corresponding to a target temperature of the material to be rolled on the entry side and the exit side of the rolling mill after the control by the remaining coolant discharging section.

The invention relates to a method for preheating at least one working roll for rolling, involving phases of: determining a target thermal expansion profile, determining an effective mean temperature profile of longitudinal segments of the working roll and for determining a target mean temperature profile, activating a plurality of inductors distributed along the working roll in order to reduce a difference between the effective mean temperature and the target mean temperature.

The invention relates to a method for preheating at least one working roll for rolling, involving phases of: determining a target thermal expansion profile, determining an effective mean temperature profile of longitudinal segments of the working roll and for determining a target mean temperature profile, activating a plurality of inductors distributed along the working roll in order to reduce a difference between the effective mean temperature and the target mean temperature.

A rolling mill is provided with: a roll for rolling a metal plate, the roll being capable of shifting in an axial direction and having a tapered portion at an end portion in the axial direction; and a heating unit configured to form an expansion portion protruding in a radial direction in the tapered portion by heating the tapered portion.

A rolling mill is provided with: a roll for rolling a metal plate, the roll being capable of shifting in an axial direction and having a tapered portion at an end portion in the axial direction; and a heating unit configured to form an expansion portion protruding in a radial direction in the tapered portion by heating the tapered portion.