Automatic deviation rectifying method for hot continuous rolling and finish rolling tail

Abstract

The invention relates to the technical field of metallurgical automatic control, and discloses a hot continuous rolling finish rolling tail automatic deviation correction method, which comprises the following steps: firstly, defining relevant parameters, for example, using a finish rolling mill with an automatic deviation correction function as Fx, and defining a calculation mode of rolling force and roll gap deviation; after the finishing mill Fx-3 throws steel, the rolling force deviation of Fx-1 is sampled and locked; and after Fx-2 steel throwing, the tail deviation direction is judged according to the deviation variable quantity and the locking value of Fx-1, and meanwhile, the rolling force deviation of Fx is sampled and locked. And after Fx-1 steel throwing, the deviation direction is judged in the same way. And then the deviation directions of the Fx and the Fx-1 are compared, the roll gap deviation adjustment amount of the Fx is calculated, amplitude limiting is set, and real-time adjustment is conducted after the Fx-1 is subjected to steel throwing. And after the Fx is subjected to steel throwing, the tail deviation rectification adjustment amount is reset. The method can effectively solve the drifting problem caused by temperature reduction of the strip steel tail of the finishing mill, has great significance in improving the rolling stability of the tail of the finishing mill, and can reduce the roller replacement frequency and improve the production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical automation control, and in particular relates to a method for automatically correcting the tail of a hot rolling finish rolling mill. Background Art

[0002] In the field of metal rolling, the hot strip finishing process presents numerous challenges. Due to the gradual thinning and significant temperature drop at the tail of the hot strip finishing process, there are also issues with the intermediate billet shape. Furthermore, after the upstream stand throws the strip, the tail is in a state of tension loss for a certain distance. These combined factors make the strip highly susceptible to tail swinging during tail throws. This tail swinging problem not only causes downtime for roll changes, severely impacting production continuity and increasing production costs, but can also adversely affect the rolling of the next strip, thereby restricting improvements in production efficiency and product quality. Therefore, properly adjusting the roll gap deviation during tail throws is critical for stabilizing the strip tail rolling process and ensuring smooth production.

[0003] Currently, some technologies exist for automatic deviation correction at the tail end of hot-strip finishing mills. For example, Publication No. CN107824618B, titled "Automatic Strip Tail Deviation Control Method," calculates the rolling force deviation of the next stand to determine the trend of rolling force deviation changes and infers the roll gap deviation adjustment. However, in actual applications, its calculation basis and method may not be accurate enough, resulting in certain limitations in its control of tail deviation and tail swinging. Another example is Publication No. CN105921525A, titled "Strip Tail Deviation Correction Method for Continuous Milling Units." While this method addresses the issues of delayed and unstable tail bending correction during intermediate billet rolling, its correction effect remains less than ideal for the complex and variable conditions of the hot-strip finishing mill tail end. Existing technologies differ in their calculation basis and method, and when addressing the multiple complex factors at the hot-strip finishing mill tail end, it is difficult to achieve comprehensive, accurate, and stable control of roll gap deviation, thus affecting the deviation correction effect and rolling stability.

[0004] To this end, we have introduced a method for automatic deviation correction of the tail of hot-rolled finishing mill. This method samples, locks and judges the rolling force deviation before the tail of the front and rear frames is thrown. The deviation direction of the tail of the strip is judged more accurately. It can effectively correct the adjustment amount of the mill roll gap deviation by combining the stiffness of each rolling mill and the plasticity of the rolled piece through automated means, and control the stability of the tail of the strip when the finishing mill throws steel. Summary of the Invention

[0005] The object of the present invention is to provide a method for automatically correcting the tail end of a hot rolling mill to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for automatically correcting the tail end of hot rolling finishing mill comprises the following steps:

[0008] S1. Define the finishing mill with tail automatic deviation correction function as F x , rolling force deviation is the operating side pressure minus the transmission side pressure, and roll gap deviation is the operating side roll gap minus the transmission side roll gap;

[0009] S2, finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking;

[0010] S3, finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 The rolling force deviation locking value determines the strip tail deviation direction;

[0011] S4, finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking;

[0012] S5, finishing mill F x-1 After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x The rolling force deviation locking value determines the strip tail deviation direction;

[0013] S6, Comparison of Finishing Mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after casting;

[0014] S7, finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled.

[0015] Preferably, in S1, x represents the stand number, indicating the xth finishing mill.

[0016] As a preferred embodiment, in S2, real-time sampling of the finishing mill F x-1 The calculation formula for rolling force deviation and locking is:

[0017]

[0018] Among them, Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value, unit is ton; F x-1dev Indicates finishing mill Fx-1 Rolling force deviation value, unit is ton; n represents F x-1 The total number of rolling force deviation sampling points, n is given by experience and ranges from 5 to 50; i represents F x-1 The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in ms, and the TA value is given by experience and ranges from 2 to 16; x represents the stand number, indicating the xth finishing mill.

[0019] As a preferred embodiment, in S3, when the strip tail deviation direction is judged, after the finishing mill Fx-2 throws the steel, the difference between the rolling force deviation of the finishing mill Fx-1 and the rolling force deviation locking value Flx-1dev of the finishing mill Fx-3 after throwing the steel is calculated in real time. The calculation formula is:

[0020] F x-1t =F x-1dev -Fl x-1dev

[0021] Among them, F x-1t Indicates finishing mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1dev The real-time difference, in ton; F x-1dev Indicates finishing mill F x-1 Rolling force deviation value, unit is ton; Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value, unit is ton, x represents the stand number, indicating the xth finishing mill;

[0022] The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp Fx-1Dev , unit is ton, Dp Fx-1Dev It is given by experience and the value range is 5-20.

[0023] Finishing Mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1dev Real-time difference F x-1t If it is greater than the dead zone Dp x-1Dev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp x-1Dev , recorded as the tail deviating to the transmission side.

[0024] As a preferred embodiment, in S4, real-time sampling of the finishing mill F x The calculation formula for rolling force deviation and locking is:

[0025]

[0026] Among them, Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation locking value, unit is ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; m represents F x The total number of rolling force deviation sampling points, which is given by experience and ranges from 5 to 50; i represents F x The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in milliseconds, which is empirically given and ranges from 2 to 16. Where x represents the stand number, indicating the xth finishing mill.

[0027] As a preferred embodiment, in S5, the strip tail deviation direction is judged, including the finishing mill F x-1 After casting, real-time calculation of finishing mill F x Rolling force deviation and finishing mill F x-2 After casting steel F x Rolling force deviation locking value Fl xdev The difference is calculated as:

[0028] F xt =F xdev -Fl xdev

[0029] Among them, F xt Indicates finishing mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev The real-time difference, in ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation locking value, unit is ton; x represents the stand number, indicating the xth finishing mill;

[0030] The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp xDev , unit is ton, Dp xDev The value is given by experience and ranges from 5 to 20;

[0031] Finishing Mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev Real-time difference F xt If it is greater than the dead zone Dp xDev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp xDev , recorded as the tail deviating to the transmission side.

[0032] As a preference, in S6, the finishing mill F x The calculation formula for the roll gap deviation adjustment is as follows:

[0033]

[0034] Among them, Gap xt Indicates finishing mill F x-1 After casting steel F x Roll gap deviation real-time adjustment amount, unit is mm; F xt Indicates finishing mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev The real-time difference, in ton; M x Indicates finishing mill F x Stiffness, unit is ton / mm; K x Indicates finishing mill F x Rolled strip plasticity, unit is ton / mm; kp represents the finishing mill F x The correction coefficient of the real-time adjustment of the roll gap deviation is kp, which is given by experience and has a range of 0-1; kd represents the finishing mill F x With F x-1 The tail deviation direction correction coefficient, kd value is given by experience. If the deviation direction is consistent, the value is 1; if the deviation direction is inconsistent, the value is -0.5-0.5. Where x represents the stand number, indicating the xth finishing mill;

[0035] Gap xlim Indicates F x Roll gap deviation real-time adjustment limit, unit is mm, Gap xlim The value is given by experience and ranges from -0.2 to 0.2.

[0036] Compared with the prior art, the technical effects and advantages of the present invention are:

[0037] (1) Define the finishing mill with tail automatic correction function as F x , rolling force deviation is the pressure on the operating side minus the pressure on the transmission side, roll gap deviation is the roll gap on the operating side minus the roll gap on the transmission side; finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking; finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 Rolling force deviation lock value determines the tail deviation direction; finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking; finishing mill Fx-1 After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x Rolling force deviation lock value determines the tail deviation direction; compare finishing mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after steel throwing; waiting for finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled;

[0038] (2) During the hot rolling finishing process, the interaction of multiple factors, such as the temperature drop at the tail of each stand, the shape problem of the intermediate billet, and the tension loss problem after the upstream stand is thrown, can easily cause the tail swing phenomenon. This automatic correction method can comprehensively consider these complex factors, and through the precise monitoring and analysis of the rolling force deviation and the roll gap deviation, effectively adjust the roll gap deviation, thereby improving the tail swing problem caused by the changes in these factors. By effectively controlling the roll gap deviation through automated means, the stability of the tail of the strip during the finishing rolling process is ensured, providing a strong guarantee for the smooth progress of the entire hot rolling finishing production process.

[0039] (3) A stable rolling process can reduce the number of roll change stops due to problems such as tail swinging, avoid production stagnation caused by frequent roll changes, and reduce equipment maintenance costs. Reducing the number of roll changes means reducing production interruptions, improving production efficiency, and thus increasing output, which is of great significance to improving the production efficiency of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flowchart of the method for automatically correcting the tail end of hot rolling provided by an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of a rolling mill comparison for the method of automatic deviation correction of the hot rolling finishing tail provided by the present invention. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] See also Figure 1 The present invention provides a technical solution: a method for automatically correcting the tail of hot rolling finishing mill, defining the finishing mill with the tail automatic correction function as Fx , rolling force deviation is the pressure on the operating side minus the pressure on the transmission side, roll gap deviation is the roll gap on the operating side minus the roll gap on the transmission side; finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking; finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 Rolling force deviation lock value determines the tail deviation direction; finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking; finishing mill F x-1 After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x Rolling force deviation lock value determines the tail deviation direction; compare finishing mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after steel throwing; waiting for finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled.

[0044] Specifically, the execution process of this method is as follows Figure 1 As shown, the following steps are included:

[0045] S1, define the finishing mill with tail automatic correction function as F x , rolling force deviation is the operating side pressure minus the transmission side pressure, and roll gap deviation is the operating side roll gap minus the transmission side roll gap; where x represents the frame number, indicating the xth finishing mill.

[0046] S2, finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking.

[0047] Wherein, the real-time sampling finishing mill F x-1 The rolling force deviation and locking calculation formula is:

[0048]

[0049] Among them, Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value, unit is ton; F x-1dev Indicates finishing mill F x-1 Rolling force deviation value, unit is ton; n represents F x-1The total number of rolling force deviation sampling points, which is given by experience and ranges from 5 to 50; i represents F x-1 The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in milliseconds, which is empirically given and ranges from 2 to 16. Where x represents the stand number, indicating the xth finishing mill.

[0050] S3, finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 The rolling force deviation locking value determines the deviation direction of the strip tail.

[0051] The step of determining the deviation direction of the tail of the strip steel includes:

[0052] Finishing mill F x-2 After casting, real-time calculation of finishing mill F x-1 Rolling force deviation and finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value Fl x-1dev The difference is calculated as:

[0053] F x-1t =F x-1dev -Fl x-1dev

[0054] Among them, F x-1t Indicates finishing mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1dev The real-time difference, in ton; F x-1dev Indicates finishing mill F x-1 Rolling force deviation value, unit is ton; Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation lock value, in ton. x represents the stand number, indicating the xth finishing mill.

[0055] The step of determining the deviation direction of the tail of the strip steel includes:

[0056] The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp Fx-1Dev , the unit is ton, the value is given by experience and the value range is 5-20.

[0057] The step of determining the deviation direction of the tail of the strip steel includes:

[0058] Finishing Mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1devReal-time difference F x-1t If it is greater than the dead zone Dp x-1Dev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp x-1Dev , recorded as the tail deviating to the transmission side.

[0059] S4, finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking.

[0060] Wherein, the real-time sampling finishing mill F x The rolling force deviation and locking calculation formula is:

[0061]

[0062] Among them, Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation locking value, unit is ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; m represents F x The total number of rolling force deviation sampling points, which is given by experience and ranges from 5 to 50; i represents F x The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in milliseconds, which is empirically given and ranges from 2 to 16. Where x represents the stand number, indicating the xth finishing mill.

[0063] S5, finishing mill F x-1 After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x The rolling force deviation locking value determines the deviation direction of the strip tail.

[0064] The step of determining the deviation direction of the tail of the strip steel includes:

[0065] Finishing mill F x-1 After casting, real-time calculation of finishing mill F x Rolling force deviation and finishing mill F x-2 After casting steel F x Rolling force deviation locking value Fl xdev The difference is calculated as:

[0066] F xt =F xdev -Fl xdev

[0067] Among them, F xt Indicates finishing mill F x-1 After casting steel F xRolling force deviation and locking value Fl xdev The real-time difference, in ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation lock value, in ton. x represents the stand number, indicating the xth finishing mill.

[0068] The step of determining the deviation direction of the tail of the strip steel includes:

[0069] The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp xDev , the unit is ton, the value is given by experience and the value range is 5-20.

[0070] The step of determining the deviation direction of the tail of the strip steel includes:

[0071] Finishing Mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev Real-time difference F xt If it is greater than the dead zone Dp xDev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp xDev , recorded as the tail deviating to the transmission side.

[0072] S6, Comparison Finishing Mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after casting.

[0073] Among them, the comparative finishing mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment calculation, including:

[0074] Finishing Mill F x The calculation formula for the roll gap deviation adjustment is as follows:

[0075]

[0076] Among them, Gap xt Indicates finishing mill F x-1 After casting steel F x Roll gap deviation real-time adjustment amount, unit is mm; F xt Indicates finishing mill F x-1 After casting steel F x Rolling force deviation and locking value Flxdev The real-time difference, in ton; M x Indicates finishing mill F x Stiffness, unit is ton / mm; K x Indicates finishing mill F x Rolled strip plasticity, unit is ton / mm; kp represents the finishing mill F x Roll gap deviation real-time adjustment correction coefficient, the value is given by experience, the range is 0-1; kd represents the finishing mill F x With F x-1 The correction coefficient for the tail deviation direction is given by experience. If the deviation direction is consistent, the value is 1. If the deviation direction is inconsistent, the value is -0.5-0.5. Where x represents the stand number, indicating the xth finishing mill.

[0077] Wherein, the finishing mill F x The design limit of the roll gap deviation adjustment includes:

[0078] Gap xlim Indicates F x The real-time adjustment limit of the roll gap deviation is in mm. The value is given based on experience and the range is -0.2-0.2.

[0079] S7, waiting for finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and the next piece is ready for rolling. Where x represents the stand number, which means the xth finishing mill.

[0080] The implementation process of the method of the present invention is described below with reference to specific application examples.

[0081] In this application example, the following steps are performed, taking the last stand in conventional hot rolling mill as an example:

[0082] (1) The finishing mill with the tail automatic deviation correction function is defined as F8, the rolling force deviation is the operating side pressure minus the transmission side pressure, and the roll gap deviation is the operating side roll gap minus the transmission side roll gap:

[0083] (2) After finishing mill F5 throws steel, the rolling force deviation of finishing mill F7 is sampled in real time and locked;

[0084] The calculation formula for real-time sampling and locking of the rolling force deviation of the finishing mill F7 is:

[0085]

[0086] Assuming the sampling interval is 10ms and a total of 5 sampling points, the detailed rolling force deviation data are shown in Table 1 below:

[0087] Table 1 Rolling force deviation data

[0088] i 1 2 3 4 5 <![CDATA[F 7dev(i) ]]> 15 16 14 14 16

[0089] The calculation can obtain the rolling force deviation locking value Fl of the finishing mill F7 after steel throwing 7dev It is 15 tons.

[0090] (3) After the finishing mill F6 throws the steel, the strip tail deviation direction is determined based on the real-time rolling force deviation change of the finishing mill F7 and the rolling force deviation lock value of the finishing mill F7.

[0091] Among them, it is assumed that the real-time rolling force deviation of the finishing mill F7 is recorded after the finishing mill F6 throws the steel, and the rolling force deviation dead zone for judging the deviation direction of the tail strip is set to Dp Fx-1Dev The data is shown in Table 2 below:

[0092] Table 2 Data of real-time rolling force deviation and deviation dead zone of finishing mill F7

[0093] i 1 2 3 4 5 <![CDATA[Fl 7dev(i) ]]> 15 15 15 15 15 <![CDATA[F 7dev(i) ]]> 23 24 25 24 23 <![CDATA[F 7t(i) ]]> 8 9 10 9 8 <![CDATA[Dp F7Dev ]]> 5 5 5 5 5

[0094] Calculation shows that after the finishing mill F6 throws the strip, the tail of the strip before the F7 entrance deviates to the operating side.

[0095] (4) After finishing mill F6 throws steel, the rolling force deviation of finishing mill F8 is sampled in real time and locked;

[0096] The calculation formula for real-time sampling and locking of the rolling force deviation of the finishing mill F8 is:

[0097]

[0098] Assuming a sampling interval of 10ms and a total of 5 sampling points, the detailed rolling force deviation data are shown in Table 3 below:

[0099] Table 3 Rolling force deviation data

[0100] i 1 2 3 4 5 <![CDATA[F 8dev(i) ]]> 20 21 22 18 19

[0101] The calculation can obtain the rolling force deviation locking value Fl of the finishing mill F8 after steel throwing 8dev It is 20 tons.

[0102] (5) After the finishing mill F7 throws the steel, the strip tail deviation direction is determined based on the real-time rolling force deviation change of the finishing mill F8 and the rolling force deviation lock value of the finishing mill F8.

[0103] Among them, it is assumed that the real-time rolling force deviation of the finishing mill F8 is recorded after the finishing mill F7 throws the steel, and the rolling force deviation dead zone for judging the deviation direction of the tail strip is set to Dp Fx-1Dev The data are shown in Table 4 below:

[0104] Table 4. Data of real-time rolling force deviation and deviation dead zone of finishing mill F8

[0105] i 1 2 3 4 5 <![CDATA[Fl 8dev(i) ]]> 20 20 20 20 20 <![CDATA[F 8dev(i) ]]> 30 32 34 28 26 <![CDATA[F 8t(i) ]]> 10 12 14 8 6 <![CDATA[Dp F8Dev ]]> 5 5 5 5 5

[0106] Calculation shows that after the finishing mill F7 throws the steel, the tail of the strip before the F8 entrance deviates to the operating side.

[0107] (6) Compare the deviation directions of the tail ends of the finishing mills F8 and F7, calculate and design the limit for the roll gap deviation adjustment of the finishing mill F8, and adjust it in real time after the finishing mill F7 throws the steel.

[0108] The calculation formula for adjusting the roll gap deviation of the finishing mill F8 by comparing the deviation directions of the tail ends of the finishing mill F8 and F7 is as follows:

[0109]

[0110] Assuming a sampling interval of 10ms and a total of 5 sampling points, the detailed calculation data is shown in Table 5 below:

[0111] Table 5 Calculation data table of 5 sampling points

[0112]

[0113]

[0114] (7) After the finishing mill F8 throws the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled.

[0115] Through the above application examples, it can be found that the method of automatic deviation correction of the hot rolling finishing tail of the present invention corrects the deviation of the rolling mill roll gap, which is beneficial to optimizing the tail swinging problem caused by changes in multiple factors such as the reduction of the tail temperature of the strip of each frame, the plate shape problem of the intermediate billet, and the loss of tension after the upstream frame is thrown when the strip is thrown at the tail of the finishing mill. It plays a key role in stabilizing the rolling of the strip tail, and is of great significance to reducing the number of roll changes and increasing production.

[0116] A method for automatically correcting the tail of a hot rolling finishing mill is first defined as a finishing mill with an automatic tail correction function as F x , rolling force deviation is the pressure on the operating side minus the pressure on the transmission side, and roll gap deviation is the roll gap on the operating side minus the roll gap on the transmission side; after that, the finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking; finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 Rolling force deviation lock value determines the tail deviation direction; finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking; finishing mill F x-1After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x The rolling force deviation lock value determines the tail deviation direction; finally, compare the finishing mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after steel throwing; waiting for finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled;

[0117] This method is highly beneficial for optimizing the tail stripping conditions at the finishing mill. During the hot strip finishing process, multiple factors, including reduced strip tail temperature at each stand, intermediate bar shape issues, and post-strip tension loss in upstream stands, can interact to easily cause tail stripping. This automatic deviation correction method comprehensively considers these complex factors. By precisely monitoring and analyzing rolling force and roll gap deviations, it effectively adjusts the roll gap deviation, thereby alleviating the tail stripping issues caused by these factors.

[0118] This automatic deviation correction method plays a key role in stabilizing the tail rolling of the strip. A stable rolling process reduces roll change downtime due to problems like tail swinging, avoiding production stagnation caused by frequent roll changes, thereby improving production efficiency and increasing output. By effectively controlling roll gap deviation through automated means, the stability of the strip tail during finishing rolling is ensured, providing a strong guarantee for the smooth operation of the entire hot-rolled finishing rolling process and playing a significant role in improving the company's production efficiency.

[0119] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for automatically correcting the tail end of hot rolling finishing, characterized in that: The steps include: S1. Define the finishing mill with tail automatic deviation correction function as F x , rolling force deviation is the operating side pressure minus the transmission side pressure, and roll gap deviation is the operating side roll gap minus the transmission side roll gap; S2, finishing mill F x-3 After casting, real-time sampling of finishing mill F x-1 Rolling force deviation and locking; S3, finishing mill F x-2 After casting, according to the finishing mill F x-1 Real-time rolling force deviation variation and finishing mill F x-1 The rolling force deviation locking value determines the strip tail deviation direction; S4, finishing mill F x-2 After casting, real-time sampling of finishing mill F x Rolling force deviation and locking; S5, finishing mill F x-1 After casting, according to the finishing mill F x Real-time rolling force deviation variation and finishing mill F x The rolling force deviation locking value determines the strip tail deviation direction; S6, Comparison of Finishing Mill F x With F x-1 The tail deviation direction, the finishing mill F x Roll gap deviation adjustment amount calculation and design limit, in finishing mill F x-1 Real-time adjustment after casting; S7, finishing mill F x After throwing the steel, the tail correction adjustment amount is reset to zero and wait for the next piece to be rolled.

2. The method for automatically correcting the tail end of hot rolling finishing according to claim 1, characterized in that: In S1, x represents the stand number, indicating the xth finishing mill.

3. The method for automatically correcting the tail end of hot rolling finishing according to claim 1, characterized in that: In S2, real-time sampling of finishing mill F x-1 The calculation formula for rolling force deviation and locking is: Among them, Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value, unit is ton; F x-1dev Indicates finishing mill F x-1 Rolling force deviation value, unit is ton; n represents F x-1 The total number of rolling force deviation sampling points, n is given by experience and ranges from 5 to 50; i represents F x-1 The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in ms, and the TA value is given by experience and ranges from 2 to 16; x represents the stand number, indicating the xth finishing mill.

4. The method for automatically correcting the tail end of hot rolling finishing according to claim 1, characterized in that: In S3, the strip tail is judged to be running in the direction of deviation, and the finishing mill F x-2 After casting, real-time calculation of finishing mill F x-1 Rolling force deviation and finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value Fl x-1dev The difference is calculated as: F x-1t =F x-1dev -In x-1dev Among them, F x-1t Indicates finishing mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1dev The real-time difference, in ton; F x-1dev Indicates finishing mill F x-1 Rolling force deviation value, unit is ton; Fl x-1dev Indicates finishing mill F x-3 After casting steel F x-1 Rolling force deviation locking value, unit is ton, x represents the stand number, indicating the xth finishing mill; The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp Fx-1Dev , unit is ton, Dp Fx-1Dev It is given by experience and the value range is 5-20; Finishing Mill F x-2 After casting steel F x-1 Rolling force deviation and locking value Fl x-1dev Real-time difference F x-1t If it is greater than the dead zone Dp x-1Dev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp x-1Dev , recorded as the tail deviating to the transmission side.

5. The method for automatically correcting the tail end of hot rolling finishing according to claim 1, characterized in that: In S4, real-time sampling of finishing mill F x The calculation formula for rolling force deviation and locking is: Among them, Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation locking value, unit is ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; m represents F x The total number of rolling force deviation sampling points, m is given by experience and ranges from 5 to 50; i represents F x The number of real-time sampling points for rolling force deviation; the time interval between two sampling points is recorded as TA, in ms, and the TA value is given by experience and ranges from 2 to 16; where x represents the stand number, indicating the xth finishing mill.

6. The method for automatically correcting the tail end of hot rolling finishing according to claim 1, characterized in that: In S5, the deviation direction of the strip tail is determined, including: Finishing mill F x-1 After casting, real-time calculation of finishing mill F x Rolling force deviation and finishing mill F x-2 After casting steel F x Rolling force deviation locking value Fl xdev The difference is calculated as: F xt =F xdev -In xdev Among them, F xt Indicates finishing mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev The real-time difference, in ton; F xdev Indicates finishing mill F x Rolling force deviation value, unit is ton; Fl xdev Indicates finishing mill F x-2 After casting steel F x Rolling force deviation locking value, unit is ton; x represents the stand number, indicating the xth finishing mill; The rolling force deviation dead zone of the tail strip deviation direction is defined as Dp xDev , unit is ton, Dp xDev The value is given by experience and ranges from 5 to 20; Finishing Mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev Real-time difference F xt If it is greater than the dead zone Dp xDev , recorded as the tail deflection to the operating side; if it is less than the dead zone -Dp xDev , recorded as the tail deviating to the transmission side.

7. The method for automatically correcting the tail end of hot rolling finishing according to claim 6, characterized in that: In S6, finishing mill F x The calculation formula for the roll gap deviation adjustment is as follows: Among them, Gap xt Indicates finishing mill F x-1 After casting steel F x Roll gap deviation real-time adjustment amount, unit is mm; F xt Indicates finishing mill F x-1 After casting steel F x Rolling force deviation and locking value Fl xdev The real-time difference, in ton; M x Indicates finishing mill F x Stiffness, unit is ton / mm; K x Indicates finishing mill F x Rolled strip plasticity, unit is ton / mm; kp represents the finishing mill F x The correction coefficient of the real-time adjustment of the roll gap deviation is kp, which is given by experience and has a range of 0-1; kd represents the finishing mill F x With F x-1 The tail deviation direction correction coefficient, kd value is given by experience. If the deviation direction is consistent, the value is 1; if the deviation direction is inconsistent, the value is -0.5-0.

5. Where x represents the stand number, indicating the xth finishing mill; Gap xlim Indicates F x Roll gap deviation real-time adjustment limit, unit is mm, Gap xlim The value is given by experience and ranges from -0.2 to 0.2.

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