Abstract:
A current temperature is ascertained for sections of a strip ahead of a first mill stand. The temperatures of the strip sections are predicted with a prediction horizon corresponding to multiple strip sections, including when each strip section is milled in the first mill stand for which time a nip profile formed by the working rolls is predicted. A control parameter for milling a specific strip section in the first mill stand is ascertained for controlling a control device of the first mill stand. A manipulated variable curve for the control device, influencing the nip profile of a nip formed by working rolls of the first mill stand, is set for the prediction horizon and optimized for the predicted nip profile and a desired profile. The current value of the optimized manipulated variable curve corresponds to the control parameter which is fed to the control device as the manipulated variable.
Abstract:
The joint properties of a metal strip being rolled in a hot strip rolling mill, especially a steel strip, are adjusted in the cooling stretch of said mill by cooling. According to the invention, a time-related cooling course is predetermined for each strip point of the metal strip. An individual cooling curve is established as a function of time for each strip point, the established time curve is constantly compared with the model time-related cooling curve for each strip point and process control signals for controlling and/or regulating the cooling stretch are derived from this comparison. The corresponding device is provided with a calculating device and a process control device.
Abstract:
Strip tension in metal strip subjected to a plastic deformation such as skin or dressing rolling, stretch bend leveling or stretching is adjusted by local variation of the temperature to establish a temperature profile which minimizes waviness and camber in metal strip.
Abstract:
For detecting the temperature profile of a moving strip, strip is caused to pass in contact with a series of hollow rotors which are spaced across the strip width, and each of which is supported by a gas bearing. A thermal detector is located within each rotor to respond to the temperature of that part of the strip in contact with the rotor.The rotors may also be used to detect the variation in tension across the strip width. In that case, the thermal detectors can modify the tension measurements to compensate for thermal errors.
Abstract:
A rolling mill with a cooling zone for cooling and scissors for cross-cutting metal strips, which are preferably made of steel. A method and a device enables metal strips with thicknesses >4 mm and/or metal strips made of high-strength materials to be cross-cut by means of scissors arranged after a production line and a cooling zone. In the method, the metal strip (6) is cooled in the cooling zone (10) to a specified temperature profile in the longitudinal direction of the metal strip (6) such that the metal strip (6) has a higher temperature in the region of the strip head of the trailing metal strip portion (31) and the strip base of the leading metal strip portion (32) than in the upstream and downstream regions.
Abstract:
The invention pertains to a device for influencing the temperature distribution over the width of a slab or a strip, particularly in hot strip rolling mill, wherein at least one cooling device is provided that features nozzles for applying a cooling medium, wherein the nozzles are arranged and/or actuated in such a way that the cooling medium is applied, in particular, at positions at which an elevated temperature is determined. The invention furthermore pertains to a device for influencing the state of the surface evenness of the strip by means of strip cooling, wherein the cooling device is controlled in dependence on the state of surface evenness of the strip in such a way that the surface unevenness is reduced or eliminated. In addition, this invention makes it possible to purposefully influence the strip contour, wherein the strip or the slab is cooled widthwise in such a way that the strip contour approximates a desired target contour more closely.
Abstract:
The present invention provides a method to control the flatness of a metal sheet or plate by effectively preventing waviness from occurring at the edge portions of the sheet or plate when it is cooled to the room temperature after completing hot rolling, and an apparatus to carry out the method: and relates to a method to control the flatness of a metal sheet or plate by homogenizing the surface temperature distribution of the metal sheet or plate through; measuring the surface temperatures of the metal sheet or plate at the edge portions and the center portion across its width between two rolling stands of a tandem finishing mill, or at the entry to and/or the exit from a reversing finishing mill, or after completing hot rolling, or after hot leveling; controlling the heating temperatures of the edge portions and/or the center portion based on the measured surface temperatures; and then cooling the metal sheet or plate after completing the finishing rolling.
Abstract:
In a method for cooling hot-rolled profiled sections from the rolling heat, wherein the profiled sections are formed of section parts of different mass, wherein, by using measuring-technological means in cooperation with a computer with the aid of a computing program, the quantity of heat to be proportionally removed from the different section parts in accordance with their mass and temperature and the amount of cooling medium required therefor are calculated and controlled, the course of temperature for the rolling stock in the rolling mill is simulated already before the actual rolling and cooling process by performing several simulation calculations by varying the cooling parameters in the simulation calculation to obtain calculated parameters. The actual values are measured upstream and downstream of the cooling stretch. The adjustments of the desired cooling process are controlled based on the calculated parameters obtained from the simulations and the actual values measured upstream and downstream of the cooling stretch. A device for performing the method has a closed active loop of five linked functional units.
Abstract:
A current temperature is ascertained for sections of a strip ahead of a first mill stand. The temperatures of the strip sections are predicted with a prediction horizon corresponding to multiple strip sections, including when each strip section is milled in the first mill stand for which time a nip profile formed by the working rolls is predicted. A control parameter for milling a specific strip section in the first mill stand is ascertained for controlling a control device of the first mill stand. A manipulated variable curve for the control device, influencing the nip profile of a nip formed by working rolls of the first mill stand, is set for the prediction horizon and optimized for the predicted nip profile and a desired profile. The current value of the optimized manipulated variable curve corresponds to the control parameter which is fed to the control device as the manipulated variable.
Abstract:
The invention pertains to a device for influencing the temperature distribution over the width of a slab or a strip, particularly in hot strip rolling mill, wherein at least one cooling device is provided that features nozzles for applying a cooling medium, wherein the nozzles are arranged and/or actuated in such a way that the cooling medium is applied, in particular, at positions at which an elevated temperature is determined. The invention furthermore pertains to a device for influencing the state of the surface evenness of the strip by means of strip cooling, wherein the cooling device is controlled in dependence on the state of surface evenness of the strip in such a way that the surface unevenness is reduced or eliminated. In addition, this invention makes it possible to purposefully influence the strip contour, wherein the strip or the slab is cooled widthwise in such a way that the strip contour approximates a desired target contour more closely.