A provisional elongation strain difference distribution Δε(x) of a metal strip during rolling is found under conditions in which out-of-plane deformation of the metal strip is restrained. A critical buckling strain difference distribution Δε.sub.cr(x) is found based on the provisional elongation strain difference distribution Δε(x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. In cases in which the provisional elongation strain difference distribution Δε(x) exceeds the critical buckling strain difference distribution Δε.sub.cr(x), the difference between the provisional elongation strain difference distribution Δε(x) and the critical buckling strain difference distribution Δε.sub.cr(x) is found, and this difference is added to the provisional elongation strain difference distribution Δε(x) to find a true elongation strain difference distribution Δε′(x). Rolling conditions are set based on the true elongation strain difference distribution Δε′(x), and the metal strip is rolled, thereby controlling the profile of the metal strip.

A rolling mill control system and method includes use of sensors located between rolling mill stands to directly measure metal sheet or plate flatness, thickness profile, position, and the camber of the rolls in the mill. A feedback loop control system adjusts or adapts rolling mill control mechanisms to control the rolling process.

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 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 casting-rolling integrated plant that is capable of producing, from a steel melt, in a cost-effective manner and with high productivity, a hot-rolled finished strip having a thickness of ≤0.6 mm, an excellent flatness, and an excellent profile by dividing the thickness reduction into at least three stages (roughing, intermediate and finishing train), measuring the actual profile after the roughing, intermediate and finishing train, and equipping the stands in the roughing, intermediate and finishing train with actuators for influencing the strip profile and/or the strip flatness.

A casting-rolling integrated plant that is capable of producing, from a steel melt, in a cost-effective manner and with high productivity, a hot-rolled finished strip having a thickness of ≤0.6 mm, an excellent flatness, and an excellent profile by dividing the thickness reduction into at least three stages (roughing, intermediate and finishing train), measuring the actual profile after the roughing, intermediate and finishing train, and equipping the stands in the roughing, intermediate and finishing train with actuators for influencing the strip profile and/or the strip flatness.

Flatness of a hot-rolled steel sheet in a coil is improved when the hot-rolled steel sheet is wound with a mandrel in a hot-rolling process to manufacture a coil. The mandrel has a protruding shape with a center portion in an axial direction protruding from both end portions when seen from a lateral side in the axial direction. Regarding a peripheral length difference, which is a difference between a peripheral length of the center portion of the mandrel and a peripheral length at a predetermined distance from the center portion, the ratio of the peripheral length difference to the peripheral length of the center portion is preferably 0.0002 to 0.012. The protruding shape may be a trapezoidal shape or a polynomial function shape.

There are provided a work-side position measurement device and a drive-side position measurement device for directly measuring positions of roll chocks in a rolling direction, and positions of upper and lower working rolls and upper and lower backup rolls in the rolling direction are adjusted to zero point or predetermined positions. Alternatively, a change caused in the strip wedge due to a minute crossing of the axes of working rolls and backup rolls is calculated, and the quantities of leveling of a work-side rolling reduction cylinder device and a drive-side rolling reduction cylinder device are adjusted to make the strip edge equal to or smaller than a predetermined value. Accordingly, the bilateral asymmetry (strip wedge) of the thickness distribution of a rolled material is easily adjusted even in the event that the positions of the roll chocks in the rolling direction are changed due to wear on various components.

There are provided a work-side position measurement device and a drive-side position measurement device for directly measuring positions of roll chocks in a rolling direction, and positions of upper and lower working rolls and upper and lower backup rolls in the rolling direction are adjusted to zero point or predetermined positions. Alternatively, a change caused in the strip wedge due to a minute crossing of the axes of working rolls and backup rolls is calculated, and the quantities of leveling of a work-side rolling reduction cylinder device and a drive-side rolling reduction cylinder device are adjusted to make the strip edge equal to or smaller than a predetermined value. Accordingly, the bilateral asymmetry (strip wedge) of the thickness distribution of a rolled material is easily adjusted even in the event that the positions of the roll chocks in the rolling direction are changed due to wear on various components.

A substrate (e.g., metal or non-metal sheet) can have multiple textures on a surface of the substrate. The various textures can be impressed or applied on the surface of the substrate by passing the substrate between multiple pairs of work rolls that each include at least one textured work roll for transferring a texture of the work roll onto the surface of the substrate. The pairs of work rolls apply the various textures on the surface of the substrate while maintaining a thickness of the substrate (e.g., with substantially no reduction in a thickness of the substrate). A single pass of the substrate between the pairs of work rolls can allow various different textures, patterns, or features to be applied to the surface of the substrate while the thickness of the substrate remains substantially constant.