Disclosed is a coil width control method including: a step in which a control unit generates a prediction model for predicting the width shrinkage of a coil, which occurs in the heat-treatment process and post-treatment process of a cold-rolled steel sheet production process, on the basis of historical operating results; a step in which the control unit receives the input width of the coil entering the heat-treatment process; and a step in which the control unit predicts the output width of the coil after the post-treatment process on the basis of the received input width and the conditions of the cold-rolled steel sheet production process, and controls in-furnace temperature and in-furnace tension of the heat-treatment process and elongation of the post-treatment process.

Disclosed is a coil width control method including: a step in which a control unit generates a prediction model for predicting the width shrinkage of a coil, which occurs in the heat-treatment process and post-treatment process of a cold-rolled steel sheet production process, on the basis of historical operating results; a step in which the control unit receives the input width of the coil entering the heat-treatment process; and a step in which the control unit predicts the output width of the coil after the post-treatment process on the basis of the received input width and the conditions of the cold-rolled steel sheet production process, and controls in-furnace temperature and in-furnace tension of the heat-treatment process and elongation of the post-treatment process.

A device and method of preparing metal blanks including applying a series of dimples in metal feed stock.

A device and method of preparing metal blanks including applying a series of dimples in metal feed stock.

A provisional elongation strain difference distribution (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 .sub.cr(x) is found based on the provisional elongation strain difference distribution (x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. When the provisional elongation strain difference distribution (x) exceeds the critical buckling strain difference distribution .sub.cr(x), the difference between the provisional elongation strain difference distribution (x) and the critical buckling strain difference distribution .sub.cr(x) is found, and added to the provisional elongation strain difference distribution (x) to find a true elongation strain difference distribution (x). Rolling conditions are set based on the true elongation strain difference distribution (x), and the metal strip is rolled, thereby controlling the metal strip's profile.

A provisional elongation strain difference distribution (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 .sub.cr(x) is found based on the provisional elongation strain difference distribution (x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. When the provisional elongation strain difference distribution (x) exceeds the critical buckling strain difference distribution .sub.cr(x), the difference between the provisional elongation strain difference distribution (x) and the critical buckling strain difference distribution .sub.cr(x) is found, and added to the provisional elongation strain difference distribution (x) to find a true elongation strain difference distribution (x). Rolling conditions are set based on the true elongation strain difference distribution (x), and the metal strip is rolled, thereby controlling the metal strip's profile.

A method for determining the stamping quality of profiled bar includes steps of: a) upstream of the rolling stand performing shaping, the initial speed V.sub.A of the starting product is determined and the initial diameter D.sub.A or initial cross-sectional area F.sub.A are determined contactlessly. b) After the rolling stand, the final speed V.sub.E of the end product is measured and the diameter D.sub.E or area F.sub.E of a virtual enveloping shell for the end product is determined contactlessly. c) The diameter D.sub.N of a virtual, round end product is determined contactlessly as D.sub.N=square root of (D.sub.A.sup.2*V.sub.A/V.sub.E) and/or the average cross-sectional area F.sub.NE of the end product (2) is determined contactlessly as F.sub.NE=F.sub.A*V.sub.A/V.sub.E. d1) The characteristic stamping variable PKG is calculated, and the characteristic stamping variable PKG is compared with a pre-set setpoint value PKG.sub.set. A device for carrying out the method is also provided.

A method for determining the stamping quality of profiled bar includes steps of: a) upstream of the rolling stand performing shaping, the initial speed V.sub.A of the starting product is determined and the initial diameter D.sub.A or initial cross-sectional area F.sub.A are determined contactlessly. b) After the rolling stand, the final speed V.sub.E of the end product is measured and the diameter D.sub.E or area F.sub.E of a virtual enveloping shell for the end product is determined contactlessly. c) The diameter D.sub.N of a virtual, round end product is determined contactlessly as D.sub.N=square root of (D.sub.A.sup.2*V.sub.A/V.sub.E) and/or the average cross-sectional area F.sub.NE of the end product (2) is determined contactlessly as F.sub.NE=F.sub.A*V.sub.A/V.sub.E. d1) The characteristic stamping variable PKG is calculated, and the characteristic stamping variable PKG is compared with a pre-set setpoint value PKG.sub.set. A device for carrying out the method is also provided.

A rolling controller executes speed and tension control, and roll gap and plate thickness control when rolling speed is less than a boundary value, while executing roll gap and plate tension control, and speed and plate thickness control when the rolling speed is equal to or greater than the boundary value. If the rolling speed rises across the boundary value, the rolling controller sets the rolling speed to zero such that a speed correction amount in the speed and tension control before the transboundary is not reflected to a calculation executed in the speed control amount of the rolling speed after the transboundary.

A rolling controller executes speed and tension control, and roll gap and plate thickness control when rolling speed is less than a boundary value, while executing roll gap and plate tension control, and speed and plate thickness control when the rolling speed is equal to or greater than the boundary value. If the rolling speed rises across the boundary value, the rolling controller sets the rolling speed to zero such that a speed correction amount in the speed and tension control before the transboundary is not reflected to a calculation executed in the speed control amount of the rolling speed after the transboundary.