Method for correcting deviation of center line of strip steel at finish rolling inlet

Abstract

The invention discloses a method for correcting center line deviation of strip steel at a finish rolling inlet, which comprises the following steps of: acquiring head center line deviation and width deviation maximum value of the strip steel at the finish rolling inlet, body width deviation average value, running speed of a conveying belt steel roller way, and distance from thermal detection before finish rolling to a vertical line of a front vertical roller group; and the head of the strip steel at the finish rolling inlet is tracked in real time, the pre-swing opening degree of the front vertical roll set is calculated, when the head of the strip steel at the finish rolling inlet reaches the front vertical roll set, the vertical rolls execute the short-stroke opening degree, and the pressure on the two sides of the front vertical roll set is monitored in real time. The method has the beneficial effects that the finish rolling inlet strip steel center line deviation can be corrected by controlling the opening degree of the vertical roll before finish rolling and the roll gap deviation of the first rack in actual production according to the method, the method is simple and easy to implement, correction of the finish rolling inlet strip steel center line deviation is facilitated, and the method has good application prospects in improving finish rolling strip threading stability. The positive significance is realized on improving the strip steel rolling stability.

Description

Technical Field

[0001] The invention relates to the technical field of fine metallurgy finishing rolling control, in particular to a method for correcting center line deviation of a finishing rolling entrance strip. Background Art

[0002] In the field of hot-rolled plate and strip rolling, due to the reversible rolling of the single-stand roughing mill, there will be deviations in the center line and head and tail width of the intermediate billet, and there will also be cumulative deviations during the intermediate roller transportation process. If not corrected in time, it will affect the strip threading and rolling stability of the finishing mill.

[0003] In the prior art, in order to optimize the above-mentioned problem, most operating methods are to prevent the hot rolling center line from running off during finishing rolling. For example, the patent with announcement number CN112872043B introduces a control method for preventing the head of the rolled piece from running off during the hot rolling single-stand rolling process, and proposes a method for pre-adjusting the deviation of the roll gap of each odd pass according to the center line deviation of the rough rolling outlet, which is beneficial to reducing the problem of the head of the rolled piece running off during the reversible rolling of the single-stand rolling mill. However, there is almost no general method for correcting the center line deviation of the strip at the finishing entrance.

[0004] Therefore, there is an urgent need for a control method for correcting the centerline deviation of the strip at the finishing entrance, so that it can be effectively combined with the opening degree control of the vertical roll before finishing rolling and the roll gap deviation control of the first stand in the field of metal rolling through automation means to correct the centerline deviation of the strip at the finishing entrance and improve the stability of the strip during the threading and rolling process. Summary of the Invention

[0005] The object of the present invention is to provide a method for correcting the center line deviation of the strip at the finishing rolling entrance.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: A method for correcting the centerline deviation of a strip steel at a finishing rolling entrance comprises the following steps: S1, obtain the centerline deviation of the strip head at the finishing rolling entrance, the maximum width deviation, and the average width deviation of the strip body, the running speed of the conveyor strip roller, and the distance from the hot inspection before finishing rolling to the vertical line of the front vertical roller group; S2, real-time tracking of the strip head at the finishing rolling entrance and calculation of the pre-swing opening of the front vertical roll group; S3, when the head of the strip at the finishing rolling entrance reaches the front vertical roller group, the vertical rollers perform a short stroke opening; S4, monitoring the pressure on both sides of the front vertical roller group in real time and setting a pressure change exceeding limit threshold; S5, when the pressure on one side increases to reach the over-limit threshold, the roller gap deviation of the first stand of the finishing rolling mill is adjusted.

[0007] Furthermore, in step S3, the judgment condition for the strip head at the finishing rolling entrance to reach the front vertical roll group is: , x dis Indicates the real-time forward position of the strip head at the finishing rolling entrance after the pre-finishing hot inspection, in mm; x com It indicates the position compensation value of the strip head at the finishing rolling entrance to the front vertical roll group, the unit is m, the xcom value is given by experience, and the value range is [0.1,1].

[0008] in, , It represents the running speed of the conveyor belt roller, in m / s; t represents the running time of the strip at the finishing rolling entrance, in s.

[0009] Furthermore, the calculation formula for the pre-swing opening degree of the front vertical roller group in step S2 is: , Gap F1E Indicates the pre-swing opening of the front vertical roller group, in mm; w set Indicates the width of rough rolled strip at the exit, in mm; Cen Dev Indicates the maximum deviation of the center line of the strip head at the finishing entrance, in mm; Wid Dev Indicates the maximum width deviation of the strip head at the finishing rolling entrance, in mm; w com Indicates the pre-swing opening compensation value of the front vertical roller group, in mm, w com The value is given by experience and ranges from [5,20].

[0010] Furthermore, the calculation formula for the short stroke opening degree of the vertical roller in step S3 is: , Gap F1Eb Indicates the opening degree of the vertical roller in short stroke, in mm; w set Indicates the width of rough-rolled strip at the exit, in mm; Wid Devb w represents the average deviation of the strip width at the finishing rolling entrance, in mm; comb Indicates the short stroke opening compensation value of the vertical roller, in mm, w comb The value is given by experience and ranges from [2,10].

[0011] Furthermore, the calculation formula for adjusting the roller gap deviation of the first stand of the finishing rolling mill in step S5 is: , G od Indicates the deviation of the roller gap of the first stand of the finishing rolling mill, in mm; F max Indicates the threshold value of the pressure exceeding the limit on one side of the front vertical roller group, in ton. This value is given by experience and the range is [100,150]. op Indicates the operating side pressure of the front vertical roller group, in ton; F dr Indicates the pressure on the transmission side of the front vertical roller group, in ton; G Fkp G represents the conversion coefficient between the deviation of the roller gap of the first stand of the finishing mill and the pressure deviation of the front vertical roll, Fkp The value is given by experience and ranges from [0.01, 0.05].

[0012] The method for correcting the centerline deviation of the strip at the finishing rolling entrance according to the present invention has the following beneficial effects: According to this method, in actual production, the centerline deviation of the strip at the finishing rolling entrance can be corrected by controlling the opening degree of the vertical rolls before finishing rolling and the roll gap deviation of the first stand; The method is simple and easy to implement, and is beneficial to correcting the center line deviation of the strip at the finishing rolling entrance. It has positive significance for improving the finishing rolling threading stability and improving the strip rolling stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flowchart of the method for correcting the centerline deviation of the strip at the finishing rolling entrance provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the equipment layout of the method for correcting the center line deviation of the strip at the finishing entrance provided by the present invention.

[0014] The reference numerals are as follows: 1. Working rolls of the first stand of finishing rolling mill; 2. Support rolls of the first stand of finishing rolling mill; 3. Vertical rolls on the driving side before finishing rolling mill; 4. Vertical rolls on the operating side before finishing rolling mill; 5. Strip steel at the entrance of finishing rolling mill; 6. Heat inspection before finishing rolling mill. DETAILED DESCRIPTION

[0015] 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.

[0016] like Figure 1 As shown, a method for correcting the center line deviation of the strip at the finishing rolling entrance includes the following steps: S1, obtain the centerline deviation of the head of the strip 5 at the finishing rolling entrance, the maximum width deviation, and the average width deviation of the body, the running speed of the conveyor roller, and the distance from the hot inspection 6 before finishing rolling to the vertical line of the front vertical roller group; Among them, the maximum deviation of the center line of the strip 5 head at the finishing rolling entrance is recorded as Cen Dev , the maximum width deviation is recorded as Wid Dev , the average deviation of the body width is recorded as Wid Devb The running speed of the conveyor belt steel roller is recorded as V ta The distance from the hot inspection 6 before finishing rolling to the vertical line of the front vertical roll group is x1. The front vertical roll group refers to the vertical roll 3 on the driving side before finishing rolling and the vertical roll 4 on the operating side before finishing rolling.

[0017] S2, real-time tracking of the head of the strip 5 at the finishing rolling entrance, and calculation of the pre-swing opening of the front vertical roll group; The calculation formula for the real-time forward position of the head of the strip 5 at the finishing rolling entrance after the pre-finishing hot inspection 6 is: , x dis Indicates the real-time forward position of the strip steel 5 head at the finishing rolling entrance after passing the pre-finishing hot inspection 6, in meters; Indicates the running speed of the conveyor belt roller, in m / s; t indicates the running time of the strip steel 5 at the finishing rolling entrance, in s; The calculation formula for the pre-swing opening degree of the front vertical roller group is: , Gap F1E Indicates the pre-swing opening of the front vertical roller group, in mm; w set Indicates the width of rough rolled strip at the exit, in mm; Cen Dev Indicates the maximum deviation of the center line of the strip 5 head at the finishing entrance, in mm; Wid Dev Indicates the maximum width deviation of the strip 5 head at the finishing entrance, in mm; w com Indicates the pre-swing opening compensation value of the front vertical roller group, in mm, w com The value is given by experience and ranges from [5,20].

[0018] S3, when the head of the strip 5 at the finishing rolling entrance reaches the front vertical roller group, the vertical rollers perform a short stroke opening; Among them, the judgment conditions for the head of the strip 5 at the finishing rolling entrance to reach the front vertical roller group are: , x dis Indicates the real-time forward position of the strip 5 head at the finishing rolling entrance after the pre-finishing hot inspection 6, in mm; x comIndicates the position compensation value of the strip 5 head at the finishing rolling entrance to the front vertical roller group, the unit is m, x com The value is given by experience and ranges from [0.1,1].

[0019] The calculation formula for the short stroke opening of the vertical roller is: , Gap F1Eb Indicates the opening degree of the vertical roller in short stroke, in mm; w set Indicates the width of rough-rolled strip at the exit, in mm; Wid Devb Indicates the average deviation of the strip width at the finishing entrance, in mm; w comb Indicates the short stroke opening compensation value of the vertical roller, in mm, w comb The value is given by experience and ranges from [2,10].

[0020] S4, monitoring the pressure on both sides of the front vertical roller group in real time and setting a pressure change exceeding limit threshold; Among them, the pressure on both sides of the front vertical roller group is recorded as F dr and F op , F dr is the transmission side pressure, F op is the operating side pressure, and the over-limit threshold is recorded as F max .

[0021] S5, when the pressure on one side increases and reaches the over-limit threshold, adjusting the gap deviation of the rollers in the first stand of the finishing rolling mill; The calculation formula for adjusting the deviation of the roller gap of the first stand of the finishing rolling mill is: , G od Indicates the gap deviation of the first stand rollers in the finishing mill (roll gap C1 on the operating side minus roll gap C2 on the transmission side), where the first stand rollers in the finishing mill consist of the working roll 1 and the support roll 2 of the first stand, in mm; F max Indicates the threshold value of the pressure exceeding the limit on one side of the front vertical roller group, in ton. This value is given by experience and the range is [100,150]. op Indicates the operating side pressure of the front vertical roller group, in ton; F dr Indicates the pressure on the transmission side of the front vertical roller group, in ton; G Fkp G represents the conversion coefficient between the deviation of the roller gap of the first stand of the finishing mill and the pressure deviation of the front vertical roll, Fkp The value is given by experience and ranges from [0.01, 0.05].

[0022] The implementation process of the method of the present invention is described below with reference to specific embodiments.

[0023] In this embodiment, the following steps are performed: S1. Obtain the maximum centerline deviation of the strip 5 at the finishing rolling entrance, which is 5 mm, the maximum width deviation, which is 2 mm, and the average body width deviation, which is 0.3 mm. The conveyor roller speed is 0.8 m / s. The distance from the pre-finishing hot inspection 6 to the vertical line of the front vertical roller group is 7 m. The front vertical roller group refers to the vertical roller 3 on the front driving side of finishing rolling and the vertical roller 4 on the front operating side of finishing rolling. The vertical line is perpendicular to the line connecting the vertical roller 3 on the front driving side of finishing rolling and the vertical roller 4 on the front operating side of finishing rolling. S2. Real-time tracking of the head of the strip 5 at the finishing rolling entrance is performed, and the pre-swing opening of the front vertical roll group is calculated; Among them, the calculation formula for the real-time forward position of the head of the strip 5 at the finishing rolling entrance after the pre-finishing hot inspection is: , The real-time forward position x of the strip head 5 at the finishing rolling entrance after the pre-finishing hot inspection 6 dis 0.8t: The calculation formula for the pre-swing opening degree of the front vertical roller group is: , The detailed parameters and results are shown in Table 1 below: Table 1 S3. When the head of the strip steel 5 at the finishing rolling entrance reaches the front vertical roller group, the vertical rollers perform a short stroke opening.

[0024] Among them, the judgment conditions for the head of the strip 5 at the finishing rolling entrance to reach the front vertical roller group are: , The head of strip 5 at the finishing rolling entrance reaches the position compensation value x of the front vertical roller group com The value is 1m, and the distance x1 from the vertical line of the front vertical roll group to the heat detection 6 before finishing rolling is 7m. From step S2, it can be seen that the real-time forward position x of the head of the strip 5 at the finishing rolling entrance after passing the heat detection 6 before finishing rolling is dis is 0.8t, and when t≥10, the judgment condition that the head of the strip 5 at the finishing rolling entrance reaches the front vertical roll group is met; The calculation formula for the short stroke opening of the vertical roller is: , The front vertical roller group performs the short stroke opening compensation value w comb The value is 2mm, and the other parameters can be known from step S2. The vertical roller performs short stroke opening Gap F1EbThe calculated result is 1254mm.

[0025] (4) Monitor the pressure on both sides of the front vertical roller group in real time and set a pressure change exceeding limit threshold.

[0026] (5) When the pressure on one side increases to the over-limit threshold, adjust the gap deviation of the rollers in the first stand of the finishing rolling mill; Among them, the calculation formula for adjusting the roller gap deviation of the first stand of finishing rolling is: , The parameters and results at time t1-t5 are listed in Table 2 below: Table 2 From Table 2, we can see that at t4 and t5, F dr和 F op All smaller than F max , so G od is 0.0, at t1, t2 and t3, the operating side pressure of the front vertical roller group is greater than the over-limit threshold, and the following formula is used for calculation: , Through the above embodiments, it can be found that the method for correcting the centerline deviation of the strip at the finishing entrance of the present invention can correct the centerline deviation of the strip at the finishing entrance 5 by controlling the opening degree of the front vertical roll group and the roll gap deviation of the first stand in actual production.

[0027] In summary, the control method of this embodiment obtains the center line deviation, maximum width deviation, and average body width deviation of the strip head at the finishing entrance of this block, the running speed of the conveyor strip roller, and the distance from the thermal inspection to the front vertical roller group before finishing rolling; the strip head at the finishing entrance is tracked in real time, and the pre-swing opening of the front vertical roller group is calculated; when the strip head reaches the front vertical roller group, the vertical roller executes the short stroke opening; the pressure on both sides of the front vertical roller group is monitored in real time, and the pressure change over-limit threshold is set; when the pressure on one side increases to reach the over-limit threshold, the gap deviation of the finishing first stand roller group is adjusted, which is beneficial to correct the center line deviation of the strip at the finishing entrance, and has positive significance for improving the finishing threading stability and improving the strip rolling stability.

[0028] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for correcting the centerline deviation of the strip at the finishing rolling entrance, characterized in that: The following steps are involved: S1, obtain the centerline deviation of the strip head at the finishing rolling entrance, the maximum width deviation, and the average width deviation of the strip body, the running speed of the conveyor strip roller, and the distance from the hot inspection before finishing rolling to the vertical line of the front vertical roller group; S2, real-time tracking of the strip head at the finishing rolling entrance and calculation of the pre-swing opening of the front vertical roll group; S3, when the head of the strip at the finishing rolling entrance reaches the front vertical roller group, the vertical rollers perform a short stroke opening; S4, monitoring the pressure on both sides of the front vertical roller group in real time and setting a pressure change exceeding limit threshold; S5, when the pressure on one side increases to reach the over-limit threshold, the roller gap deviation of the first stand of the finishing rolling mill is adjusted.

2. A method for correcting the centerline deviation of the strip at the finishing rolling entrance according to claim 1, characterized in that: In step S3, the judgment condition that the strip head at the finishing rolling entrance reaches the front vertical roller group is: ， x dis Indicates the real-time forward position of the strip head at the finishing rolling entrance after the pre-finishing hot inspection, in mm; x com Indicates the position compensation value of the strip head at the finishing rolling entrance to the front vertical roller group, the unit is m, x com The value is given by experience and ranges from [0.1,1].

3. The method for correcting the centerline deviation of the strip at the finishing rolling entrance according to claim 2, characterized in that: ， It represents the running speed of the conveyor belt roller, in m / s; t represents the running time of the strip at the finishing rolling entrance, in s.

4. The method for correcting the centerline deviation of the strip at the finishing rolling entrance according to claim 1, characterized in that: The calculation formula for the pre-swing opening degree of the front vertical roller group in step S2 is: ， Gap F1E Indicates the pre-swing opening of the front vertical roller group, in mm; w set Indicates the width of rough rolled strip at the exit, in mm; Cen Dev Indicates the maximum deviation of the center line of the strip head at the finishing entrance, in mm; Wid Dev Indicates the maximum width deviation of the strip head at the finishing rolling entrance, in mm; w com Indicates the pre-swing opening compensation value of the front vertical roller group, in mm, w com The value is given by experience and ranges from [5,20].

5. The method for correcting the centerline deviation of the strip at the finishing rolling entrance according to claim 1, characterized in that: The calculation formula for the short stroke opening of the vertical roller in step S3 is: ， Gap F1Eb Indicates the opening degree of the vertical roller in short stroke, in mm; w set Indicates the width of rough-rolled strip at the exit, in mm; Wid Devb w represents the average deviation of the strip width at the finishing rolling entrance, in mm; comb Indicates the short stroke opening compensation value of the vertical roller, in mm, w comb The value is given by experience and ranges from [2,10].

6. The method for correcting the centerline deviation of the strip at the finishing rolling entrance according to claim 1, characterized in that: The calculation formula for adjusting the gap deviation of the first stand of the finishing mill in step S5 is: ， G od Indicates the deviation of the roller gap of the first stand of the finishing rolling mill, in mm; F max Indicates the threshold value of the pressure exceeding the limit on one side of the front vertical roller group, in ton. This value is given by experience and the range is [100,150]. op Indicates the operating side pressure of the front vertical roller group, in ton; F dr Indicates the pressure on the transmission side of the front vertical roller group, in ton; G Fkp G represents the conversion coefficient between the deviation of the roller gap of the first stand of the finishing mill and the pressure deviation of the front vertical roll, Fkp The value is given by experience and ranges from [0.01, 0.05].

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