A method for adjusting roll gap in cold continuous rolling process of ultra-high strength steel

Abstract

This invention provides a roll gap adjustment method applicable to the cold continuous rolling process of ultra-high strength steel, comprising the following steps: First, establishing a thickness deviation prediction model for ultra-high strength steel, and predicting the thickness deviation rate γ for the nth and (n+1th)th thicknesses of the i-th coil of incoming strip. i,n γ i,n+1 Calculations are performed; secondly, a roll gap adjustment prediction model is established to calculate the mill roll gap adjustment ΔS. i An objective function for the optimal roll gap adjustment during the rolling process is established. Based on an optimization method, the objective function for the optimal roll gap adjustment is solved to obtain the optimal roll gap adjustment. This method can overcome the full-length thickness variation and head-to-tail thickness deviation issues that occur in the traditional automatic thickness control system of cold rolling mills during the rolling of ultra-high strength steel, greatly improving the thickness control accuracy of ultra-high strength steel.

Description

A method for adjusting roll gap in the cold continuous rolling process of ultra-high strength steel Technical Field

[0001] This invention belongs to the field of cold rolling technology, and specifically relates to a method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel. Background Technology

[0002] In response to the "dual-carbon" development strategy, reducing vehicle weight and energy consumption have become development goals for the automotive industry. Simultaneously, to further improve vehicle collision safety, high-strength and thin-film steel has become a research and development direction for automotive steel from advanced steel companies. To meet the strength requirements of high-end automotive steel, typical high-strength steel grades such as DP steel, TRIP steel, CP steel, and TAM steel have emerged. However, with the increasing strength of automotive steel strips, higher requirements have been placed on production processes such as hot rolling, cold rolling, continuous annealing, and leveling. The cold rolling process, in particular, determines the strip shape and thickness variation, and affects the stability of the strip within the continuous annealing furnace. In the cold continuous rolling process, due to the performance differences between ultra-high-strength steel and ordinary strip steel, under the same deformation, the absolute value of the rolling force and the mill bounce are greater for ultra-high-strength steel. The amount of roll gap adjustment and tension adjustment required to adjust the same thickness deviation is also much greater than for ordinary strip steel, making it difficult to control the exit thickness accuracy of the strip.

[0003] Currently, the thickness control system of cold rolling mills mainly uses inlet and outlet thickness gauges and speed measuring instruments for feedforward and feedback control to reduce the impact of incoming material thickness fluctuations. However, with the expansion of the production scale of gigapascal-grade ultra-high strength automotive steel sheets, the current cold rolling thickness control system can no longer meet the thickness control accuracy requirements of ultra-high strength steel. Therefore, in order to reduce the large thickness fluctuations and long thickness deviations at the beginning and end of the strip during the rolling process, the focus is on improving the automatic thickness control system of the cold rolling process to reduce the longitudinal thickness difference fluctuation of ultra-high strength steel. Summary of the Invention

[0004] To address the issues of large thickness fluctuations and significant thickness variations along the entire length of the strip during rolling, this invention improves the automatic thickness control system for the cold continuous rolling process to reduce the longitudinal thickness variation amplitude of ultra-high strength steel. The technical solution adopted in this invention is as follows:

[0005] A method for adjusting roll gap in the cold continuous rolling process of ultra-high strength steel includes the following steps:

[0006] First, a thickness deviation prediction model for ultra-high strength steel is established to predict the thickness deviation rate γ for the nth and (n+1th)th thickness deviations of the i-th roll of incoming strip steel. i,n γ i,n+1 Perform calculations;

[0007] Secondly, a model for predicting the roll gap adjustment amount is established to calculate the roll gap adjustment amount ΔS of the rolling mill. i ,

[0008] Establish the objective function for the optimal adjustment of the roll gap during the rolling process;

[0009] The objective function for the optimal roll gap adjustment is solved using an optimization method to obtain the optimal roll gap adjustment.

[0010] Furthermore, the prediction model for the thickness deviation of the nth and (n+1)th rolls of the i-th incoming strip is as follows:

[0011]

[0012] Where: h i,set V is the set value for the outlet thickness of the incoming strip steel of volume i, in mm; 0,i,n V 0,i,n+1 These are the inlet strip velocities at points n and n+1 of the i-th roll of incoming strip, measured by the inlet speed measuring instrument, in m·min. -1 η i V is the correction factor for the incoming strip steel of volume i; 1,i,n V 1,i,n+1 These are the strip exit speeds of the i-th roll of incoming strip measured by the exit speed measuring instrument at points n and n+1, respectively, in m·min. -1 H i,set The set value for the inlet thickness of the incoming strip in volume i, in mm; ΔH i,n ΔH i,n+1 The thickness deviations at the nth and (n+1th)th entry points of the i-th roll of incoming strip are respectively, in mm.

[0013] Furthermore, the formula for the roll gap adjustment prediction model is as follows.

[0014] ΔS i =ΔS fi +ΔS qi +ΔS mi

[0015] Where: ΔS fi This represents the feedback roll gap adjustment amount caused by the thickness deviation of the incoming strip in the i-th volume;

[0016] ΔS qi ΔS represents the feedforward roll gap adjustment caused by the thickness deviation of the incoming strip in volume i; mi To estimate the adjustment amount of the roll gap during the strip rolling process.

[0017] Furthermore: the feedforward roll gap adjustment ΔS caused by the thickness deviation of the i-th roll of incoming strip. qi Use the following formula.

[0018]

[0019] Where: a i,n ,a i,n+1 M represents the percentage deviation of the nth and (n+1th)th actual thickness of the strip in the i-th roll; M is the mill stiffness, kN·mm. -1 ;m i W represents the number of actual thickness deviation percentages of the incoming strip steel in volume i; i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm, H. i,set The inlet thickness setting value for the i-th volume of incoming strip steel is in mm.

[0020] Furthermore: the feedback roll gap adjustment ΔS caused by the thickness deviation of the i-th roll of incoming strip. fi Use the following formula.

[0021]

[0022] Where: h i,set The set value for the exit thickness of the incoming strip steel of volume i, in mm; a i,n ,a i,n+1 m represents the percentage deviation of the nth and (n+1th)th actual thickness of the incoming strip steel from the i-th roll; i The number of actual thickness deviation percentages of the incoming strip steel in volume i; M represents the mill stiffness in kN·mm. -1 W i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm.

[0023] Furthermore: the estimated adjustment amount ΔS of the roll gap during the strip rolling process. mi The formula is as follows:

[0024]

[0025] Wherein: γ i,n γ i,n+1 These are the predicted thickness deviation rates for the nth and (n+1th)th layers of the incoming strip steel from volume i, respectively; h i,set The set value for the exit thickness of the incoming strip steel of volume i, in mm; m i The number of actual thickness deviation percentages of the incoming strip steel in volume i; M represents the mill stiffness in kN·mm. -1 W i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm.

[0026] Furthermore, the objective function for establishing the optimal roll gap adjustment is as follows.

[0027]

[0028] Furthermore: Based on the optimization method, the objective function for the optimal roll gap adjustment is solved, and the process of obtaining the optimal roll gap adjustment is as follows:

[0029] C1: Weighting coefficient β; Total number of roll gap adjustments n; Current exit thickness deviation rate γ i (ΔS i Set the roll gap adjustment step size d and the roll gap adjustment coefficient k;

[0030] C2: ΔS = ΔS - kd, calculate the average out-of-tolerance rate of the optimized outlet thickness respectively. Calculate the absolute value φ of the difference between the current export thickness deviation rate and the average export thickness deviation rate at all previous discrete time points that have undergone optimization. 1i (ΔS i ), calculate the average φ of the sum of all out-of-tolerance rates of the optimized exit thickness at all discrete time points and the current sum of the exit thickness out-of-tolerance rates. 2i (ΔS i ), calculate G(ΔS) of the objective function for the current thickness deviation. i );

[0031] C3: Determine whether the roll gap adjustment satisfies ΔS ≥ ΔS i,min If satisfied, then calculate and extract G(ΔS). i When the gap is at its minimum, the corresponding roll gap adjustment ΔS i If the condition is not met, then jump back to step C2.

[0032] The invention provides a method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel. First, a model for predicting the thickness deviation of ultra-high strength steel is established. Second, a model for estimating the roll gap adjustment amount is developed. Then, an objective function for the optimal roll gap adjustment amount during the rolling process is established, thereby reducing the thickness fluctuation during the rolling process of ultra-high strength steel.

[0033] It has the following advantages: This method can overcome the full-length thickness difference fluctuation and head and tail thickness deviation that occur in the traditional automatic thickness control system of cold rolling mill during the rolling of ultra-high strength steel, and greatly improve the thickness control accuracy of ultra-high strength steel. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 is a flowchart of the optimization process for the optimal roll gap adjustment of a cold rolling mill.

[0036] Figure 2 illustrates the feedforward control principle of the cold continuous rolling mill.

[0037] Figure 3 illustrates the feedback control principle of the cold rolling mill unit;

[0038] Figure 4 illustrates the principle of cold rolling mill adjustment prediction.

[0039] Figure 5 illustrates the comprehensive control principle of roll gap adjustment in a cold rolling mill. Detailed Implementation

[0040] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0045] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0046] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0047] Figure 1 is a flowchart of the optimization process for the optimal roll gap adjustment of a cold rolling mill.

[0048] A method for adjusting roll gap in the cold continuous rolling process of ultra-high strength steel consists of the following calculation and analysis steps:

[0049] First, a thickness deviation prediction model for ultra-high strength steel is established to predict the thickness deviation rate γ for the nth and (n+1th)th thickness deviations of the i-th roll of incoming strip steel. i,n γ i,n+1 Perform calculations;

[0050] Secondly, a model for predicting the roll gap adjustment amount is established to calculate the roll gap adjustment amount ΔS of the rolling mill. i ,

[0051] Establish the objective function for the optimal roll gap adjustment during the rolling process;

[0052] The optimal roll gap adjustment amount is obtained by solving the objective function of the optimal roll gap adjustment amount using the optimization method.

[0053] Furthermore, obtain the set value h of the outlet thickness of the i-th volume of incoming strip steel. i,set mm; the speed V of the strip entering the mill at points n and n+1 of the i-th roll of incoming strip measured by the inlet speed measuring instrument. 0,i,n V 0,i,n+1 ,m·min -1 Correction factor η for incoming strip steel in Volume i i The speed V of the strip exiting the mill at point n(n+1) of the i-th roll of incoming strip, measured by the exit speed measuring instrument. 1,i,n V 1,i,n+1 ,m·min -1 ; Volume i, Incoming Strip Thickness Setting Value H i,set mm; the thickness deviation ΔH at the n+1th point of the incoming strip in volume i. i,n ΔH i,n+1 mm; Calculate the thickness deviation rate γ of the nth point of the i-th roll of incoming strip steel according to the following formula. i,n γ i,n+1 .

[0054]

[0055] Furthermore: the feedforward roll gap adjustment ΔS caused by the thickness deviation of the i-th roll of incoming strip. qi The following formula is used for mm, and its control principle is shown in Figure 2.

[0056]

[0057] Where: a i,n ,a i,n+1The percentage of the actual thickness deviation between the nth and (n+1th)th sections of the incoming strip steel from the i-th volume; M is the mill stiffness, kN·mm. -1 ;m i W represents the number of actual thickness deviation percentages of the incoming strip steel in volume i; i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm, H. i,set The inlet thickness setting value for the i-th volume of incoming strip steel is in mm.

[0058] Furthermore: the feedback roll gap adjustment ΔS caused by the thickness deviation of the i-th roll of incoming strip. fi The following formula is used for mm, and its control principle is shown in Figure 3.

[0059]

[0060] Where: h i,set The set value for the exit thickness of the incoming strip steel of volume i, in mm, a i,n ,a i,n+1 m represents the percentage deviation of the nth and (n+1th)th actual thickness of the incoming strip steel from the i-th roll; i The number of actual thickness deviation percentages of the incoming strip steel in volume i; M represents the mill stiffness in kN·mm. -1 W i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm.

[0061] Furthermore: the estimated adjustment amount ΔS of the roll gap during the strip rolling process. mi The formula is as follows: its control principle is shown in Figure 4.

[0062]

[0063] Wherein: γ i,n γ i,n+1 These are the predicted thickness deviation rates for the nth and (n+1th)th layers of the incoming strip steel from volume i, respectively; h i,set The set value for the exit thickness of the incoming strip steel of volume i, in mm; m i The number of actual thickness deviation percentages of the incoming strip steel in volume i; M represents the mill stiffness in kN·mm. -1 W i Let be the plasticity coefficient of the incoming strip steel in volume i, in N·mm.

[0064] The formula for the roll gap adjustment prediction model is as follows. Its control principle is shown in Figure 5.

[0065] ΔS i =ΔS fi +ΔS qi +ΔS mi

[0066] Where: ΔS fi This represents the feedback roll gap adjustment amount caused by the thickness deviation of the incoming strip in the i-th volume;

[0067] ΔS qi ΔS represents the feedforward roll gap adjustment caused by the thickness deviation of the incoming strip in volume i; mi To estimate the adjustment amount of the roll gap during the strip rolling process.

[0068] The objective function for establishing the optimal roll gap adjustment is as follows.

[0069]

[0070] The process of solving the objective function for the optimal roll gap adjustment based on the optimization method to obtain the optimal roll gap adjustment is as follows:

[0071] C1: Weighting coefficient β; Total number of roll gap adjustments n; Current exit thickness deviation rate γ i (ΔS i Set the roll gap adjustment step size d and the roll gap adjustment coefficient k;

[0072] C2: ΔS = ΔS - kd, calculate the average out-of-tolerance rate of the optimized outlet thickness respectively. Calculate the absolute value φ of the difference between the current export thickness deviation rate and the average export thickness deviation rate at all previous discrete time points that have undergone optimization. 1i (ΔS i ), calculate the average φ of the sum of all out-of-tolerance rates of the optimized exit thickness at all discrete time points and the current sum of the exit thickness out-of-tolerance rates. 2i (ΔS i ), calculate G(ΔS) of the objective function for the current thickness deviation. i );

[0073] C3: Determine whether the roll gap adjustment satisfies ΔS ≥ ΔS i,min If satisfied, then calculate and extract G(ΔS). i When the gap is at its minimum, the corresponding roll gap adjustment ΔS i If the condition is not met, then jump back to step C2.

[0074] The following section uses a cold rolling mill in a steel plant as an example, and combines Figure 1 and the embodiments to further illustrate the application of the roll gap adjustment method of the present invention in the cold rolling process of ultra-high strength steel.

[0075] Example 1:

[0076] (A): The set value of the exit thickness of the first roll of incoming strip steel was 2.3 mm; the strip speed at the first point of the mill inlet of the first roll of incoming strip steel, measured by the inlet speed measuring instrument, was 9 m / min. -1 The correction factor for the incoming strip of Volume 1 is 0.95; the strip exit speed at point 1 of the rolling mill for Volume 1, measured by the exit speed measuring instrument, is 14.87 m / min. -1 The set value for the inlet thickness of the first roll of incoming strip is 3.8 mm; the deviation in the first inlet thickness of the first roll of incoming strip is 0.3 mm. Calculate the deviation rate of the first point thickness of the first roll of incoming strip as 0.136.

[0077] (B): Number of actual thickness deviation percentages collected for the first roll of incoming strip steel: 1; the first and second actual thickness deviation percentages for the first roll of incoming strip steel are 0.95 and 0.97, respectively; mill stiffness: 10000 kN·mm. -1 The inlet thickness of the incoming strip in Volume 1 is set at 3.8 mm; the plasticity coefficient of the incoming strip in Volume 1 is 5000 N·mm. -1 Collect the export thickness setting value of 2.3mm for the first roll of incoming strip steel; calculate the predicted values ​​of the first and second thickness deviation rates of the first roll of incoming strip steel as 0.136 and 0.138, respectively.

[0078] (B1) Calculate the feedforward roll gap adjustment amount of 0.038 mm caused by the thickness deviation of the incoming strip steel in Volume 1.

[0079] (B2) Calculate the feedback roll gap adjustment amount of 0.069 mm caused by the thickness deviation of the incoming strip steel of Volume 1.

[0080] (B3) Calculate the estimated adjustment amount of the roll gap during the strip rolling process: 0.002 mm.

[0081] (B4) Based on feedforward ΔS qi Feedback ΔS fi and the estimated adjustment amount ΔS of the roll gap mi The mill roll gap adjustment amount is calculated to be 0.11 mm.

[0082] (C1) Collect weighting coefficient 0.4; total number of roll gap adjustments 7; current exit thickness deviation rate 0.138, set roll gap adjustment step size 0.01, roll gap adjustment coefficient 1, establish the objective function for optimizing roll gap adjustment amount, and the calculation process is shown in Table 1.

[0083]

[0084] (C2) ΔS=ΔS-kd, calculate the average out-of-tolerance rate of the optimized outlet thickness respectively. Calculate the absolute value φ of the difference between the current export thickness deviation rate and the average export thickness deviation rate at all previous discrete time points that have undergone optimization.1i (ΔS i ), calculate the average φ of the sum of all out-of-tolerance rates of the optimized exit thickness at all discrete time points and the current sum of the exit thickness out-of-tolerance rates. 2i (ΔS i ), calculate G(ΔS) of the objective function for the current thickness deviation. i ).

[0085] (C3) Determine whether the roll gap adjustment amount meets ΔS i If the value is ≥0.05, then calculate and extract G(ΔS). i When the gap is at its minimum, the corresponding roll gap adjustment ΔS i If the condition is not met, the process jumps back to step C1. The calculation result G(ΔS) in this embodiment is... i If the minimum value is 0.0804, then the roll gap is set to 0.05mm.

[0086] Table 1 Optimization process

[0087]

[0088] Example 2:

[0089] (A): The set value of the exit thickness of the second roll of incoming strip steel is 2.5 mm; the speed of the first point of the mill inlet of the second roll of incoming strip steel measured by the inlet speed measuring instrument is 10 m / min. -1 The correction factor for the incoming strip steel in Volume 2 is 0.96; the strip steel exit speed at point 1 of the rolling mill for Volume 2, measured by the exit speed measuring instrument, is 16.8 m / min. -1 The set value for the inlet thickness of the incoming strip in Volume 2 is 4.2 mm; the deviation in the thickness at the first inlet point of the incoming strip in Volume 2 is 0.36 mm; the deviation rate of the thickness at the first point of the incoming strip in Volume 2 is calculated to be 0.131.

[0090] (B): Number of actual thickness deviation percentages collected for the second batch of incoming strip steel: 1; the first and second actual thickness deviation percentages for the second batch of incoming strip steel are 0.96 and 0.98, respectively; mill stiffness: 10000 kN·mm. -1 The inlet thickness of the incoming strip in Volume 2 is set at 4.2 mm; the plasticity coefficient of the incoming strip in Volume 2 is 5000 N·mm. -1 Collect the export thickness setting value of 2.5mm for the incoming strip steel of Volume 2; calculate the predicted values ​​of the first and second thickness deviation rates of the incoming strip steel of Volume 2 as 0.131 and 0.124, respectively.

[0091] (B1) Calculate the feedforward roll gap adjustment amount of 0.042 mm caused by the thickness deviation of the incoming strip steel in Volume 2.

[0092] (B2) Calculate the feedback roll gap adjustment amount of 0.075 mm caused by the thickness deviation of the incoming strip steel in Volume 2.

[0093] (B3) Calculate the estimated adjustment amount of the roll gap during the strip rolling process: 0.008 mm.

[0094] (B4) Based on feedforward ΔS qi Feedback ΔS fi and the estimated adjustment amount ΔS of the roll gap mi The mill roll gap adjustment amount is calculated to be 0.11 mm.

[0095] (C1) Collect weighting coefficient 0.4; total number of roll gap adjustments 2; current exit thickness deviation rate 0.138, set roll gap adjustment step size 0.01, roll gap adjustment coefficient 2, establish the objective function for optimizing roll gap adjustment amount, and the calculation process is shown in Table 1.

[0096]

[0097] (C2) ΔS=ΔS-kd, calculate the average out-of-tolerance rate of the optimized outlet thickness respectively. Calculate the absolute value φ of the difference between the current export thickness deviation rate and the average export thickness deviation rate at all previous discrete time points that have undergone optimization. 1i (ΔS i ), calculate the average φ of the sum of all out-of-tolerance rates of the optimized exit thickness at all discrete time points and the current sum of the exit thickness out-of-tolerance rates. 2i (ΔS i ), calculate G(ΔS) of the objective function for the current thickness deviation. i ).

[0098] (C3) Determine whether the roll gap adjustment amount meets ΔS i If the value is ≥0.05, then calculate and extract G(ΔS). i When the gap is at its minimum, the corresponding roll gap adjustment ΔS i If the condition is not met, the process jumps back to step C1. The calculation result G(ΔS) in this embodiment is... i If the minimum value is 0.0781, then the roll gap is set to 0.05mm.

[0099] Table 2 Optimization process

[0100]

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for adjusting roll gap during the cold continuous rolling process of ultra-high strength steel, characterized in that: Includes the following steps: First, a thickness deviation prediction model for ultra-high strength steel is established to predict the thickness deviation rates for the nth and (n+1th)th thicknesses of the i-th roll of incoming strip steel. 、 The calculation is performed; the prediction model for the thickness deviation of the nth and (n+1)th layers of the i-th roll of incoming strip steel is as follows: in: For the first Thickness setting for imported strip steel at the exit (mm); ， The first one measured by the entrance speed measuring instrument respectively The strip speeds at the nth and (n+1th)th points of the mill inlet for the coiled strip, in m·min -1 ; For the first Correction factor for coiled strip steel; ， The first one measured by the exit speedometer The strip speed at the nth and (n+1th)th points of the mill exit for the coiled strip, in m·min -1 ; For the first The set value for the thickness of the incoming strip steel at the inlet, in mm; ， The first The thickness deviation at the nth and (n+1)th entry points of the incoming strip steel is measured in mm; secondly, a roll gap adjustment prediction model is established to calculate the mill roll gap adjustment. An objective function for the optimal roll gap adjustment during the rolling process is established; the optimal roll gap adjustment is obtained by solving the objective function based on the optimization method.

2. The method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 1, characterized in that: The formula for the roll gap adjustment prediction model is as follows: in: Indicates the first Feedback roll gap adjustment amount caused by thickness deviation of coiled strip steel; Indicates the first The amount of feedforward roll gap adjustment caused by the thickness deviation of the coiled strip steel; To estimate the adjustment amount of the roll gap during the strip rolling process.

3. The method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 2, characterized in that: The first Feedforward roll gap adjustment caused by thickness deviation of incoming strip steel The following formula is used: in: For the first The percentage deviation of the nth and (n+1th)th actual thicknesses of the coiled strip steel; Rolling mill stiffness, kN·mm -1 ; For the first The number of actual thickness deviation percentages of coiled strip steel; For the first Plasticity coefficient of coiled steel strip, N·mm. For the first The set value for the inlet thickness of the coiled steel strip, in mm.

4. The method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 3, characterized in that: The first Feedback roll gap adjustment caused by thickness deviation of incoming coiled strip steel The following formula is used: in: For the first The set value for the exit thickness of coiled steel strip, in mm; For the first The percentage deviation of the nth and (n+1th)th actual thicknesses of the coiled strip steel; For the first The number of actual thickness deviation percentages of coiled strip steel; Rolling mill stiffness kN·mm -1 ; For the first Plasticity coefficient of coiled steel strip, N·mm.

5. The method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 4, characterized in that: The estimated adjustment amount of the roll gap during the strip rolling process The formula is as follows: in: ， These are the predicted thickness deviation rates for the nth and (n+1th)th thicknesses of the i-th incoming strip steel, respectively. For the first The set value for the exit thickness of coiled steel strip, in mm; For the first The number of actual thickness deviation percentages of coiled strip steel; Rolling mill stiffness kN·mm -1 ; For the first Plasticity coefficient of coiled steel strip, N·mm.

6. The method for adjusting the roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 5, characterized in that: The objective function for finding the optimal roll gap adjustment is established as follows: in: The objective function is the current thickness deviation. These are weighting coefficients; It is the absolute value of the difference between the current export thickness deviation rate and the average export thickness deviation rate that has been optimized at all previous discrete time points; It is the average of the sum of all out-of-tolerance rates of the current out-of-tolerance rate and the sum of the current out-of-tolerance rates of the current out-of-tolerance rate; The out-of-tolerance rate of the exit thickness optimized for the i-th roll gap adjustment; This represents the total number of times the roll gap was adjusted. This represents the current export thickness deviation rate; This represents the average export thickness deviation rate after optimization.

7. A method for adjusting roll gap in the cold continuous rolling process of ultra-high strength steel according to claim 6, characterized in that: The objective function for the optimal roll gap adjustment is solved using an optimization method. The process for obtaining the optimal roll gap adjustment is as follows: C1: Collect weighting coefficients Total number of roll gap adjustments Current export thickness deviation rate Set the roll gap adjustment step size d and the roll gap adjustment coefficient k; C2： Calculate the average deviation rate of the optimized export thickness respectively. Calculate the absolute value of the difference between the current export thickness deviation rate and the average export thickness deviation rate at all previous discrete time points that have been optimized. Calculate the average of the sum of all out-of-tolerance rates of the current out-of-tolerance rate of the optimized out-of-tolerance rate at all discrete time points. Calculate the objective function for the current thickness deviation. ； C3: Determine if the roll gap adjustment amount is satisfied. If the conditions are met, then calculate and extract. At its minimum, the corresponding roll gap adjustment amount If the condition is not met, then jump back to step C2.

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