Method for monitoring a physical state of a hot-rolled sheet while controlling a rolling train for reverse rolling the hot-rolled sheet
View Patent ↗A method of monitoring the physical state of a hot-rolled sheet or hot-rolled strip while controlling a plate rolling train for the reversing working a hot-rolled sheet or hot-rolled strip. For the reversing rolling of the hot-rolled sheet or hot-rolled strip a rolling stand is provided. At a starting point, an initial state of the hot-rolled sheet or hot-rolled strip in a model is determined, from which state at least one physical state variable is derived. Further, a cyclical updating of the state during the working of the hot-rolled sheet by using the model of the hot-rolled sheet or hot-rolled strip and the plate rolling train is provided, wherein monitoring of the path of the hot-rolled sheet or hot-rolled strip and operating parameters influencing and/or reproducing the state are taken into account.
1. A method for monitoring a physical state of a hot-rolled, sheet, comprising:
providing a rolling train with a rolling stand for reverse rolling of a hot-rolled sheet;
providing a central control unit for controlling the rolling train;
providing a model of the hot-rolled sheet and the rolling train stored in the central control unit;
reverse rolling the hot-rolled sheet;
determining, at a starting point, a physical state of the hot-rolled sheet in the model, wherein the physical state of the hot-rolled sheet is a characteristic which is described with reference to a mathematical model and which is relevant for the reverse rolling of the hot-rolled sheet;
deriving a physical state variable from the physical state;
cyclically updating the physical state variable during the reverse rolling of the hot-rolled sheet by using the model of the hot-rolled sheet and the rolling train, wherein an update cycle is between 0.5 and 2 seconds; and
measuring operating parameters of the hot-rolled sheet or the rolling train, wherein the operating parameters are used for the cyclically updating the physical state, wherein the operating parameters are measured at a location which is different from a location of the starting point.
2. The method as claimed in claim 1 , wherein the physical state variable is selected from the group consisting of a temperature variable, a residual work-hardness variable, a phase portion variable, a grain size variable, a enthalpy variable.
3. The method as claimed in claim 1 , wherein the physical state is described by at least one physical state variable at various points of the hot-rolled sheet, wherein the various points are a plurality of points arranged along a length and over a width of the hot-rolled sheet.
4. The method as claimed in claim 3 , wherein the physical state is described by local temperature profiles at the various points.
5. The method as claimed in claim 1 , wherein the physical state is determined using a measuring device and/or with reference to a model.
6. The method as claimed in claim 1 , wherein, responsive to a predetermined event occurring, pre-calculated physical states and future sheet processing parameters derived therefrom are iteratively ascertained in a context of a pre-calculation based upon a current physical state.
7. The method as claimed in claim 6 , wherein the pre-determined event is the hot-rolled sheet reaching a specific position adjacent to points of the rolling stand and/or a cooling device and/or a descaling device and/or a user instruction.
8. The method as claimed in claim 6 , wherein the pre-determined event is a failure of a direct or indirect comparison of the current physical state with a pre-calculated physical state.
9. The method as claimed in claim 8 , wherein the comparison is performed as a result of the hot-rolled sheet reaching a specific position adjacent to points of the rolling stand and/or a cooling device and/or a descaling device.
10. The method as claimed in claim 6 , wherein parameters of a cooling device and/or a descaling device and/or the rolling stand and/or a heating device and/or a sheet speed are used as sheet processing parameters.
11. The method as claimed in claim 10 , wherein an updating of the sheet processing parameters comprises a specification of a stoppage time and/or an additional cooling or heating operation and/or a change in the sheet speed.
12. The method as claimed in claim 10 , wherein an updating of the sheet processing parameters results in an asymmetric control of upper and lower working rolls of the rolling stand.
13. The method as claimed in claim 6 , wherein current physical state and/or physical state variables derived from the current physical state, are displayed to an operator, wherein an adaptation of sheet processing parameters are carried out by the operator.
14. The method as claimed in claim 1 ,wherein a measuring device is arranged adjacent to the rolling stand, a measurement is only done for a part of the hot-rolled sheet, and wherein corrections of an unmeasured part of the hot-rolled sheet are inferred from corrections of a measured part.
15. The method as claimed in claim 1 , wherein rolling forces or torques of the rolling stand, which are dependent on the physical state variable, are used as operating parameters.
16. The method as claimed in claim 1 , wherein the operating parameters comprise parameters of a cooling device and/or a descaling device and/or the rolling stand and/or a heating device and/or a sheet speed.
17. The method as claimed in claim 1 , wherein a temporal course of the physical state and/or correction variables derived from the current physical state are retained in a memory unit of the central control unit for subsequent analysis with regard to a processing of further hot-rolled sheets.