A method for controlling a four-high rolling mill to roll a wide and thin steel sheet
By setting the balancing force of the rolling mill bending roll and support roll, optimizing the gap impact compensation, and automatically adjusting the roll gap during the rolling mill gap swing process, the problem of uncontrolled plate shape in the rolling of wide and thin steel plates was solved, and the safe and stable operation of the equipment and energy saving were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING IRON & STEEL CO LTD
- Filing Date
- 2024-04-26
- Publication Date
- 2026-06-26
AI Technical Summary
In existing technology, when rolling wide and thin steel plates, the rolling force of the mill causes the roll gaps to stick together, the rolls cannot function properly, resulting in uncontrolled plate shape and equipment damage.
By setting the balancing force of the rolling mill bending roll and support roll, optimizing the gap impact compensation, and automatically adjusting the roll gap during the rolling mill gap swing process, the thickness is controlled by the hydraulic roll gap control system to ensure that the conditions for roll shifting are met.
This enabled the rolling of wide and thin steel plates, reducing unplanned downtime and equipment damage, and improving production efficiency and energy utilization efficiency.
Smart Images
Figure CN118455276B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of steel rolling technology, and in particular to a method for controlling roll shifting in a four-roll mill when rolling wide and thin steel plates. Background Technology
[0002] During steel plate rolling, the rolling force causes the support rolls to bend and deform. Uneven contact deformation between the support rolls and the work rolls further causes the work rolls to bend, resulting in thickness variations along the width of the rolled steel plate. To eliminate the bending deformation of the rolls under rolling force and reduce the transverse thickness tolerance of the steel plate, most four-high rolling mills for wide and thick plates currently employ roll shifting for shape control, improving the plate shape and ensuring controlled thickness.
[0003] However, when rolling wide and thin steel plates, factors such as the rolling force caused by the rolling mill bounce can lead to the rolling mill roll gaps sticking together, excessive unloaded rolling force, and the roll shifting cannot function. This not only fails to improve the plate shape but also causes the plate shape to become uncontrollable, resulting in unplanned damage and equipment failure. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for controlling the roll shifting of a four-roll mill when rolling wide and thin steel plates.
[0005] To solve the above technical problems, the technical solution of the present invention is as follows:
[0006] A method for controlling roll shifting in a four-roll mill for rolling wide and thin steel plates includes:
[0007] The mill bending roll balancing force is set to 1900KN, and the support roll balancing force is set to 248Pa.
[0008] Determine if the finished steel plate thickness is less than 10mm. If so, optimize the seam impact compensation and perform reverse compensation, setting the compensation value to +0.8~+0.9.
[0009] During the mill gap shifting process, if the gap is less than 5.5mm and the rolling force is greater than 400KN, the roll shifting priority is set, and the gap is automatically adjusted through the hydraulic gap control system.
[0010] During the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 5.5mm~6mm for rolling. After the rolls are in place, the thickness is controlled by the hydraulic roll gap control system to ensure that the wide and thin steel plates are rolled out.
[0011] As a preferred embodiment of the roll shifting control method for rolling wide and thin steel plates using a four-roll mill according to the present invention, the method further includes, before setting the mill bending roll balancing force to 1900KN and the support roll balancing force to 248Pa:
[0012] Manual control is implemented for the last three rolling passes.
[0013] As a preferred embodiment of the roll shifting control method for rolling wide and thin steel plates using a four-roll mill according to the present invention, the manual adjustment includes setting the maximum value of roll shifting to 150mm and the minimum value of roll shifting to -150mm.
[0014] As a preferred embodiment of the roll shifting control method for rolling wide and thin steel plates using a four-roll mill according to the present invention, the step of determining whether the finished steel plate thickness is less than 10mm, and if so, optimizing the seam impact compensation and performing reverse compensation, setting the compensation value to +0.8~+0.9 includes:
[0015] Set the compensation value to +0.8.
[0016] As a preferred embodiment of the roll shifting control method for rolling wide and thin steel plates using a four-roll mill according to the present invention, wherein: during the rolling process, when the roll gap is set to be less than 5.5mm, setting the roll gap to 5.5mm~6mm for steel rolling includes:
[0017] Set the roll gap to 5.5mm.
[0018] The beneficial effects of this invention are:
[0019] (1) This invention ensures that the rolling mill completes the rolling of wide and thin steel plates, ensuring that the overall thickness meets customer requirements and reducing unplanned processes.
[0020] (2) This invention can reduce energy consumption caused by the return of heated steel plates to the furnace and equipment downtime, promote green development, and increase the amount of carbon neutrality tasks that enterprises can accomplish. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a schematic flowchart of the method for controlling roll shifting in a four-roll mill for rolling wide and thin steel plates provided by the present invention. Detailed Implementation
[0023] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0024] Figure 1This is a flowchart illustrating the roll shifting control method for rolling wide and thin steel plates using a four-high rolling mill, as provided in this application. The method includes steps S101 to S105, which are described in detail below:
[0025] Step S101: Manually adjust the rolling process for the last three rolling passes.
[0026] Specifically, a CVC manual intervention window has been added to the primary control interface of the rolling mill to allow for manual adjustment of the last three passes in wide and thin-gauge rolling. This manual adjustment primarily involves regulating the maximum and minimum values set for roll shifting. The adjustment method involves inputting the set values through the CVC manual intervention window, replacing the values calculated by the model with the manually entered values.
[0027] The maximum value for the roller shifting is set to 150mm, and the minimum value is set to -150mm.
[0028] Step S102: Set the mill bending roll balancing force to 1900KN and the support roll balancing force to 248Pa.
[0029] Specifically, when rolling wide and thin steel plates, the balancing forces of the bending rolls and the support rolls are reduced, thereby reducing the no-load rolling force.
[0030] In this embodiment, the balancing force of the rolling mill bending roll is reduced from 1940KN to 1900KN, and the balancing force of the support roll is reduced from 258Pa to 248Pa.
[0031] Step S103: Determine whether the thickness of the finished steel plate is less than 10mm. If so, optimize the impact compensation of the seam and perform reverse compensation, setting the compensation value to +0.8~+0.9.
[0032] Specifically, it automatically identifies steel plates with a finished thickness of less than 10mm, optimizes seam impact compensation, performs reverse compensation, and adjusts the compensation value from -0.7 to +0.8~+0.9, thereby improving the roll gap value before steel biting.
[0033] Step S104: During the mill gap shifting process, if the roll gap is less than 5.5 mm and the rolling force is greater than 400 KN, the roll shifting priority is set, and the roll gap is automatically adjusted through the hydraulic roll gap control system.
[0034] Specifically, the AGC roll gap automatic system of the rolling mill is optimized and adjusted. During the rolling mill roll gap adjustment process, if the roll gap is less than 5.5mm and the rolling force is greater than 400kN, the roll shifting setting is prioritized. After rolling is completed, the HGC automatically opens quickly to open the roll gap and ensure the conditions for roll shifting are met.
[0035] Step S105: During the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 5.5mm~6mm for rolling. After the rolls are in place, the thickness is controlled by the hydraulic roll gap control system to ensure that the wide and thin steel plate is rolled out.
[0036] Specifically, during the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 5.5mm~6mm for rolling. After the rolls are in place, the thickness is controlled by HGC, sacrificing the head thickness to ensure that the wide and thin steel plate is rolled out.
[0037] The following examples, 1-3, will provide a detailed explanation:
[0038] Example 1: This example provides a method for controlling roll shifting in a four-high rolling mill when rolling wide and thin steel plates, including the following steps:
[0039] Step S101: Add a CVC manual intervention window to the primary control interface of the rolling mill to manually adjust the last three passes of wide and thin specification rolling. Manual adjustment mainly involves regulating the maximum and minimum values set for roll shifting. Specifically, the maximum value for roll shifting is set to 150mm, and the minimum value is set to -150mm.
[0040] Step S102: Reduce the bending roll balancing force and the support roll balancing force. Reduce the bending roll balancing force from 1940KN to 1900KN and the support roll balancing force from 258Pa to 248Pa.
[0041] Step S103: Automatically identify steel plates with a finished product thickness of less than 10mm, optimize seam impact compensation, perform reverse compensation, and adjust the compensation value from -0.7 to +0.8 to improve the roll gap value before steel biting.
[0042] Step S104: During the mill's swaying gap process, if the roll gap is less than 5.5mm and the rolling force is greater than 400kN, the roll shifting setting is prioritized. After rolling is completed, the HGC automatically opens quickly to open the roll gap and ensure the roll shifting operation conditions.
[0043] Step S105: During the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 5.5mm for rolling. After the rolls are in place, the thickness is controlled by HGC, sacrificing the head thickness to ensure that the wide and thin steel plate is rolled out.
[0044] After implementation, the rolling effect of 40 steel plates of the same specification, each 6mm thick and 3500mm wide, was continuously monitored.
[0045] Example 2: This example provides a method for controlling roll shifting in a four-roll mill when rolling wide and thin steel plates. The difference from Example 1 is that in step S103, the compensation value is adjusted from -0.7 to +0.9. All other undescribed parts are the same as in Example 1.
[0046] The rolling effect of 40 steel plates of the same specification, each 6mm thick and 3500mm wide, was continuously monitored.
[0047] Example 3: This example provides a method for controlling roll shifting in a four-roll mill when rolling wide and thin steel plates. The difference from Example 1 is that during the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 6mm for rolling. All other undescribed parts are the same as in Example 1.
[0048] The rolling effect of 40 steel plates of the same specification, each 6mm thick and 3500mm wide, was continuously monitored.
[0049] In summary, the roll shifting control method for rolling wide and thin steel plates using a four-roll mill provided in this application can ensure the proper use of the rolls, ultimately guaranteeing the completion of rolling and ensuring that the produced steel plates meet customer requirements.
[0050] In addition to the above embodiments, the present invention may have other implementation methods; all technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.
Claims
1. A method for controlling roll shifting in a four-roll mill for rolling wide and thin steel plates, characterized in that: include: Manual adjustment is performed for the last three rolling passes. The manual adjustment includes setting the maximum value of the roll shifting to 150mm and the minimum value of the roll shifting to -150mm. The mill bending roll balancing force is set to 1900KN, and the support roll balancing force is set to 248Pa. Determine if the finished steel plate thickness is less than 10mm. If so, optimize the seam impact compensation and perform reverse compensation, setting the compensation value to +0.8~+0.
9. During the mill gap shifting process, if the gap is less than 5.5mm and the rolling force is greater than 400KN, the roll shifting priority is set, and the gap is automatically adjusted through the hydraulic gap control system. During the rolling process, when the roll gap is set to less than 5.5mm, the roll gap is set to 5.5mm~6mm for rolling. After the rolls are in place, the thickness is controlled by the hydraulic roll gap control system to ensure that the wide and thin steel plates are rolled out.
2. The method for controlling roll shifting in a four-roll mill for rolling wide and thin steel plates according to claim 1, characterized in that: The process of determining whether the finished steel plate thickness is less than 10mm, and if so, optimizing the impact compensation and performing reverse compensation, setting the compensation value to +0.8~+0.9 includes: Set the compensation value to +0.
8.
3. The method for controlling roll shifting in a four-roll mill for rolling wide and thin steel plates according to claim 1, characterized in that: The process of setting the roll gap to 5.5mm~6mm during rolling when the roll gap is set to be less than 5.5mm includes: Set the roll gap to 5.5mm.