A method for improving rolling stability of thin-gauge high-strength steel

Abstract

The present invention discloses a method for improving the rolling stability of thin-gauge high-strength steel. The method comprises calibrating the parameters of the finishing mill before rolling: calibrating the side guides, setting the short stroke of the side guides at the finishing mill entrance, and setting the tapping rhythm of the heating furnace; setting the looper tension of the finishing mill based on the calibrated parameters when rolling thin-gauge high-strength steel; and adjusting the tail strip shape according to the tail wedge value of the strip during the finishing rolling. In actual production, the present invention solves the frequent occurrence of abnormalities such as head and tail deviation and rolling damage during the finishing rolling process of thin-gauge high-strength steel, thereby reducing the scrap rate caused by rolling damage.

Description

Technical Field

[0001] The present invention relates to the field of hot-rolled strip steel production in the metallurgical industry, and in particular to a method for improving the rolling stability of thin-gauge high-strength steel. Background Art

[0002] "Hot instead of cold" steel is the main achievement of the current development of hot rolling technology and the main means for the steel industry to reduce carbon emissions. Steel companies and downstream users need a large amount of "hot instead of cold" steel from a comprehensive consideration of carbon emissions, costs, etc., especially in the automotive industry. Thin-gauge high-strength steel is the main means of lightweighting cars. It can significantly reduce the weight of cars while ensuring the strength of cars. It is the main way to save costs. Therefore, the market demand for thin-gauge high-strength steel is increasing year by year. However, due to its high strength, thin-gauge high-strength steel has poor stability in the production process. The main manifestation is that the center line of the strip and the rolling center line are not on the same center line during threading, resulting in head crushing; during the rolling process, due to abnormalities such as plate shape, the frame second flow is unbalanced and scrap steel is produced; during the tail rolling process, due to abnormalities such as plate shape adjustment direction, rolling crushing occurs. The above abnormalities all have a large scrap risk, affecting rolling stability.

[0003] The rolling stability of thin-gauge high-strength steel is currently mainly controlled by reducing the reduction rate, AGC action, incoming material cross-section shape, heating temperature, etc. Patent (application number: 201610729966.8) load distribution method for improving hot-rolled thin strip rolling stability solidifies the reduction rate of the finishing mill, reduces the F1 / F2 / F7 reduction rate during the production process, adjusts the F3-F6 reduction rate, and ensures overall rolling stability; Patent (application number: 201610770344.X) a method for improving the hot-rolling stability of thin-gauge container plate improves rolling stability by jointly controlling the temperature of each section of the production process, the thickness of the roughing intermediate billet, the finishing speed, the tail F6 / F7 roll gap, and the side guide plate opening; Patent (application number: 200910248748.2) a method for stabilizing the tail of hot-rolled thin strip steel by designing a combination of tail monitoring AGC and AGC tail pressure compensation to avoid excessive or rapid adjustment of the monitoring AGC, which may cause strip deformation. The tail of the steel loses stability, effectively improving the rolling stability of the tail of the strip; Patent (application number: 201510527259.6) A method for controlling the deviation of hot-rolled strip rolling measures the transverse thickness of the rough rolling intermediate billet, calculates the wedge compensation value of the finishing roll gap, and reasonably sets the reduction on both sides of each rolling mill of the finishing rolling, thereby reducing the scrap steel caused by rolling deviation and improving the rolling stability; Patent (application number: 201910400284.6) A method for stable rolling of thin niobium-added wide-band steel reduces the occurrence of production accidents such as forward bending and tail swinging by controlling the soaking time, furnace temperature deviation, rough rolling RDT temperature, finishing mill stand water, and finished product convexity, thereby improving the rolling line stability; In actual production, thin-gauge high-strength steel frequently suffers from abnormalities such as head-tail deviation and crushing during the finishing rolling process, and finishing middle crushing, but the above measures cannot solve the problems of head-tail deviation and middle crushing in the finishing rolling process. In severe cases, it leads to crushed scrap steel, so measures need to be taken to control it. Summary of the Invention

[0004] The present invention aims to provide a method for improving the rolling stability of thin-gauge high-strength steel. This method addresses the frequent occurrence of abnormalities such as head-end deviation and rolling failure during the finishing rolling process of thin-gauge high-strength steel in actual production, thereby reducing the scrap rate caused by rolling failure. To achieve this objective, the present invention provides the following technical solutions:

[0005] A method for improving rolling stability of thin-gauge high-strength steel, the method comprising:

[0006] Before rolling, the parameters of the finishing mill are calibrated: the side guide plates are calibrated, the short stroke of the guide plates at the entrance of the finishing mill is set, and the tapping rhythm of the heating furnace is set;

[0007] Based on the calibrated parameters, the looper tension of the finishing mill is set when rolling thin-gauge high-strength steel;

[0008] During the finishing rolling of the tail, the tail plate shape is adjusted according to the wedge value of the tail of the strip.

[0009] Preferably, the calibrating of the side guide plate includes calibrating the width and opening of the side guide plate, wherein:

[0010] Eliminate the mechanical clearance of the side guide plates, calibrate the centering and opening of the side guide plates with the midpoint of the mill arch as the base point, and obtain the on-site measured values ​​of the centering and opening of the side guide plates;

[0011] Inputting the on-site measured values ​​of the side guide plate centering and opening into the calibration program;

[0012] Repeat once or more to eliminate the mechanical clearance of the side guide plates, and calibrate the centering and opening of the side guide plates with the midpoint of the rolling mill arch as the base point, so that the deviation between the actual opening measured on site and the opening set by the program is ≤5mm, and the centering deviation of the side guide plates is ≤3mm.

[0013] Preferably, the midpoint of the mill housing is obtained by measuring with a tape measure.

[0014] Preferably, the short-stroke setting of the guide plates on the inlet side of the finishing mill includes setting the short-stroke setting of the guide plates on the inlet side of the finishing mills F2, F3, F4, F5, F6 and F7.

[0015] Preferably, the short stroke setting of the guide plate at the entrance side of the finishing mill includes:

[0016] The short stroke of the side guide plate head, the short stroke of the side guide plate middle and the short stroke of the side guide plate tail of the finishing mills F2, F3, F4, F5, F6 and F7 are set in sequence and in increasing order.

[0017] Preferably, the stroke setting interval of the side guide plate head short stroke, side guide plate middle short stroke and side guide plate tail short stroke in the finishing mills F2, F3, F4, F5, F6 and F7 is 20 to 70 mm.

[0018] Preferably, the step of setting the tapping rhythm of the heating furnace includes:

[0019] When the production thickness of the steel strip is ≤2.0mm, set the heating furnace to tap steel at 200S / piece-240S / piece.

[0020] When the production thickness of the steel strip is detected to be greater than 2.0, the tapping time of the heating furnace is set to 160S / block-220S / block, wherein the production thickness of the steel strip is obtained by detecting the HMD signal at the outlet of the descaling box.

[0021] Preferably, when rolling thin gauge high strength steel, the finishing looper tension is set, including: when rolling thin gauge high strength steel, the looper tensions of the finishing mills F1, F2, F3, F4, F5 and F6 are solidified at 6% to 22%, wherein,

[0022] The tension of the finishing mill F1 is set at 6% to 13%;

[0023] The tension of the finishing mill F2 is set at 7% to 14%;

[0024] The tension of the finishing mill F3 is set at 9% to 16%;

[0025] The tension of finishing mill F4 is set at 12% to 18%;

[0026] The tension of the finishing mill F5 is set at 14% to 20%;

[0027] The tension of the finishing mill F6 is set to 16% to 22%.

[0028] Preferably, when finishing rolling the tail, adjusting the tail shape according to the wedge value of the strip tail includes:

[0029] When the wedge value is negative, the roll gap is adjusted in the negative direction; when the wedge value is positive, the roll gap is adjusted in the positive direction.

[0030] Preferably, when the wedge value is a negative value, the roll gap is tilted and adjusted in a negative direction, including:

[0031] When the wedge value of the strip tail is -10 to 0, the roll gap of the F4-F7 stands is tilted to the operating side by 0.05 to 0.15 mm according to the strip shape;

[0032] When the wedge value of the strip tail is -30 to -10, the roll gap of the F2-F7 stands is tilted to the operating side by 0.15 to 0.30 mm according to the strip shape;

[0033] When the wedge value of the strip tail is less than -30, the roll gap is adjusted during rough rolling to control the wedge value to be less than or equal to 30, and the roll gap of the F2-F7 stands is tilted by 0.15 to 0.30 mm on the operating side.

[0034] When the wedge value is positive, the roll gap is tilted and adjusted in the positive direction, including:

[0035] When the wedge value of the strip tail is 0-10, the roll gap of the F4-F7 stands is tilted and the operating side is raised by 0.05-0.15mm respectively according to the strip shape;

[0036] When the wedge value of the strip tail is 10-30, the roll gap of the F4-F7 stands is tilted to the operating side by 0.05-0.15mm according to the strip shape;

[0037] When the wedge value of the strip tail is greater than 30, the roll gap is adjusted for rough rolling to control the wedge value ≤ 30, and the roll gap tilting operation side of the F2-F7 stands is raised by 0.05 to 0.15 mm respectively.

[0038] Technical effects and advantages of the present invention:

[0039] This invention provides a method for stable rolling of thin-gauge high-strength steel without increasing equipment costs. As thickness decreases and strength increases, thin-gauge high-strength steel experiences greater rolling pressure and is sensitive to changes in plate shape, increasing production process instability. Scrap steel that deviates during head threading is effectively controlled by improving the precision of the side guides on each stand. Abrupt changes in plate shape during rolling are corrected by increasing tension. And tail deviation and crushing are controlled by adjusting the roll gap tilt based on the wedge shape. These measures achieve stable rolling of thin-gauge high-strength steel.

[0040] In actual production, during the finishing rolling process of thin-gauge high-strength steel, abnormal situations such as frequent deviation and crushing of the head and tail, and crushing in the middle of finishing rolling are solved, thereby reducing the scrap steel rate due to crushing.

[0041] The scrap steel rate and qualified rate are calculated by the weight, scrap volume and qualified rate of thin-gauge high-strength steel coils in the high-strength steel production status production report from 2019 to 2021. After the implementation of this method, the scrap steel rate was reduced from 1% to 0.07%. There was no scrap steel from December 2019 to June 2020 and from January 2021 to July 2021. At the same time, the qualified rate increased from 84.93% to 94.38%.

[0042] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of the method for improving rolling stability according to the present invention;

[0044] Figure 2 This is a statistical chart of the high-strength steel production status from 2019 to 2021 in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0045] 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.

[0046] In order to solve the deficiencies of the prior art, the present invention discloses a method for improving the rolling stability of thin-gauge high-strength steel. Figure 1 It can be seen that the method includes, before rolling, calibrating the side guide plate center and opening, setting the short stroke of the side guide plate at the entrance of the finishing mill F2-F7 and setting the steel tapping rhythm of the heating furnace; when rolling thin-gauge high-strength steel, setting the looper tension of the finishing mill F1-F7; at the tail of the finishing rolling, adjusting the tail plate shape according to the wedge value of the tail of the strip.

[0047] The method of the present invention realizes the stable rolling of thin-gauge high-strength steel by improving the whole-process production process of thin-gauge high-strength steel, wherein the thin-gauge high-strength steel is a strip steel with a thickness of ≤3.0mm and a yield strength of more than 400MPa.

[0048] Furthermore, the side guide plates are calibrated to ensure that the center lines of each rolling mill remain consistent, the center point of the rolling mill arch is measured with a tape measure, and the side guide plate alignment is measured with this point as the midpoint. First, the side guide plates are opened and closed, and the mechanical clearance of the side guide plates is eliminated by the opening and closing actions. The side guide plate alignment and opening are calibrated with the midpoint of the rolling mill arch as the base point to obtain the on-site measured values ​​of the side guide plate alignment and opening; the side guide plate alignment and opening values ​​are input into the calibration program, and the first calibration is performed using the on-site measured values ​​input into the calibration program as the calibration values; after the first calibration, the opening and closing actions are repeated once or more to eliminate the mechanical clearance of the side guide plates, and the side guide plate opening and side guide plate alignment are remeasured until the deviation between the on-site measured opening and the calculated opening is ≤5mm, and the deviation of the alignment on both sides is ≤3mm.

[0049] Furthermore, the short stroke setting of the side guide plates at the entrance of the finishing mills F2-F7 includes sequentially increasing the short stroke of the side guide plates at the head, the short stroke of the side guide plates in the middle, and the short stroke of the side guide plates at the tail of the finishing mills F2, F3, F4, F5, F6, and F7. The short stroke of the finishing side guide plates is set by the head, middle, and tail values. The actual side guide plates are positioned according to the actual width of the strip + the short stroke setting value. When the side guide plate setting value is too large, the strip deviation will be aggravated. Therefore, the short stroke setting of the head, middle, and tail is to set the short stroke of the F2-F7 entrance side guide plates according to 20 to 70 mm. The exemplary specific setting values ​​are shown in Table 1:

[0050] Table 1 F2-F7 inlet side guide plate short stroke setting table

[0051] Rack number F2 F3 F4 F5 F6 F7 Short stroke of side guide head 20～40 25～50 30～60 35～60 40～70 45～70 Side guide middle short stroke 20～40 25～50 30～60 35～60 40～70 45～70 Short stroke at the tail of the side guide 40 40 50 55 60 70

[0052] According to Table 1, the stroke setting range of the side guide head short stroke, the side guide middle short stroke and the side guide tail short stroke of the finishing mills F2, F3, F4, F5, F6 and F7 is 20-70 mm, wherein, according to the on-site conditions, the side guide head short stroke and the side guide middle short stroke of the finishing mill F2 are set to 20-40 mm, and the side guide tail short stroke is set to 40 mm; the side guide head short stroke and the side guide middle short stroke of the finishing mill F3 are set to 25-50 mm, and the side guide tail short stroke is set to 40 mm; the finishing mill F 4 The short stroke of the side guide head and the short stroke of the side guide middle are set to 30-60mm, and the short stroke of the side guide tail is set to 50mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F5 are set to 35-60mm, and the short stroke of the side guide tail is set to 55mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F6 are set to 40-70mm, and the short stroke of the side guide tail is set to 60mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F7 are set to 45-70mm, and the short stroke of the side guide tail is set to 70mm.

[0053] Furthermore, due to the thin thickness, heavy rolling load, and long rolling time of thin-gauge high-strength steel, when the heating furnace tapping rhythm is fast, the rolls cannot be effectively cooled, resulting in a rapid increase in roll crown. The increase in roll crown will cause the thin-gauge high-strength steel to have waves penetrate the scrap steel, so it is necessary to control the tapping rhythm of the heating furnace. The tapping rhythm of the heating furnace uses the HMD (hot metal detector) signal at the outlet of the primary descaling box as the reference point, and the time difference between the current slab and the next slab as the tapping rhythm. The heating operator directly sets the tapping rhythm and the heating furnace automatically performs the tapping action. When the production thickness is ≤2.0mm, the heating furnace tapping is set at 200S / block-240S / block. When the production thickness is greater than 2.0mm, the heating furnace tapping is set at 160S / block-220S / block. At this tapping rhythm, the rolls are fully cooled and the roll crown is effectively controlled.

[0054] Furthermore, since the plate shape changes frequently during the rolling process of thin-gauge high-strength steel, and increasing the tension can effectively reduce the plate shape change during the rolling process, when the thin-gauge high-strength steel is rolled in an automated process, the looper tension of the finishing mills F1-F6 is set. Preferably, the looper tension of the finishing mills F1, F2, F3, F4, F5 and F6 is solidified at 6% to 22%, and the looper tension is set in increments of 6% to 22% and solidified according to Table 2.

[0055] Table 2 Setting table of looper tension of finishing mill F1-F6

[0056] Rack number F1 F2 F3 F4 F5 F6 tension 6％～13％ 7％～14％ 9％～16％ 12％～18％ 14％～20％ 16％～22％

[0057] Furthermore, during the tail of the finishing rolling, the tail shape is adjusted based on the tail wedge value. Since the strip wedge changes as the tail shape changes, the strip shape change trend during the rolling process can be seen by observing the change in wedge. Therefore, during the tail of the finishing rolling, the wedge value is used as a reference value for tail shape adjustment, and the tail shape is adjusted according to Table 3.

[0058] Table 3 Wedge value is used as reference value for tail plate shape adjustment during finishing rolling

[0059]

[0060] According to Table 3, when finishing rolling the tail, the tail plate shape is adjusted according to the wedge value of the strip tail. When the wedge value is negative, the roll gap is adjusted in the negative direction, and when the wedge value is positive, the roll gap is adjusted in the positive direction. When the wedge value of the strip tail is -10 to 0, the roll gap tilting operation side of the F4-F7 stand rolls is pressed by 0.05 to 0.15 mm according to the strip plate shape; when the wedge value of the strip tail is -30 to -10, the roll gap tilting operation side of the F2-F7 stand rolls is pressed by 0.15 to 0.30 mm according to the strip plate shape; when the wedge value of the strip tail is 0 to 10, the roll gap tilting operation side of the F4-F7 stand rolls is raised by 0.05 to 0.15 mm according to the strip plate shape; when the wedge value of the strip tail is 10 to When the wedge value of the tail of the strip is less than -30, the roll gap of the rolls of the F4-F7 stands is tilted to the operating side by 0.05-0.15mm according to the strip shape; when the wedge value of the tail of the strip is less than -30, the roll gap is tilted for rough rolling, the wedge value is controlled to be ≤30, and the roll gap of the rolls of the F2-F7 stands is tilted to the operating side by 0.15-0.30mm; when the wedge value of the tail of the strip is greater than 30, the roll gap is tilted for rough rolling, the wedge value is controlled to be ≤30, and the roll gap of the rolls of the F2-F7 stands is tilted to the operating side by 0.05-0.15mm.

[0061] Furthermore, when the tail of the strip is finished rolled, the tail shape is adjusted according to the wedge value of the tail of the strip, and the F2 or F4 stand is focused on.

[0062] The technical points of the present invention will be further explained in conjunction with specific embodiments.

[0063] Since January 2020, the method of the present invention has been used to control the production process of thin-gauge high-strength steel. The side guide plate calibration, heating furnace steel-out rhythm, and tail plate shape adjustment are included in the operation instructions for control, and the tension is included in the process automation model for solidification.

[0064] Furthermore, according to the operating instructions, the center point of the mill arch is measured with a tape measure, and the side guide alignment is measured with this point as the midpoint. First, the side guide is opened and then closed, and the mechanical clearance of the side guide is eliminated by opening and closing. At the same time, the side guide alignment and opening degree are calibrated with the midpoint of the mill arch as the base point. During calibration, the actual measured value is used as the calibration value and input into the calibration program for calibration. After calibration, the opening and closing actions are performed again, and the opening degree and alignment are re-measured. It is required that the deviation between the actual measured opening degree and the opening degree set by the program is ≤5mm, and the centering deviation on both sides is ≤3mm;

[0065] Furthermore, the short stroke setting of the head, middle and tail is to set the short stroke of the F2-F7 inlet side guide plate according to 20~70mm. The specific setting values ​​are shown in the table below. After completion, the short stroke of the F2-F7 inlet side guide plate is set according to 20~70mm;

[0066] Furthermore, the tapping rhythm of the hot furnace is based on the HMD (hot metal detector) signal at the outlet of the primary descaling box. The heating operator directly sets the tapping rhythm and the heating furnace automatically taps the steel. When the production thickness is ≤2.0mm, the tapping rhythm is set at 200S / piece to 240S / piece. When the thickness is greater than 2.0mm, the tapping rhythm is set at 160S / piece to 220S / piece.

[0067] Furthermore, when rolling thin-gauge high-strength steel, the finishing looper tensions F1-F6 are solidified at 6% to 22%, and the looper tensions are set in increments of 6% to 22%, and solidified in the following manner: the tension of the finishing mill F1 is set at 6% to 13%; the tension of the finishing mill F2 is set at 7% to 14%; the tension of the finishing mill F3 is set at 9% to 16%; the tension of the finishing mill F4 is set at 12% to 18%; the tension of the finishing mill F5 is set at 14% to 20%; and the tension of the finishing mill F6 is set at 16% to 22%.

[0068] Furthermore, during the finishing rolling tail, the tail plate shape is adjusted according to the wedge value of the strip tail. When the wedge value is negative, the roll gap is adjusted in the negative direction. When the wedge value is positive, the roll gap is adjusted in the positive direction. During the adjustment process, focus on observing the F2 or F4 frame.

[0069] Figure 2 The production status of high-strength steel from 2019 to 2021 is shown. During the period of 2019-2021, a method for improving the rolling stability of thin-gauge high-strength steel is adopted. By statistically analyzing the weight, scrap volume, and qualified rate of thin-gauge high-strength steel coils in the production report, and obtaining the scrap rate and qualified rate, combined with Figure 2It can be seen that before 2019, the average scrap steel rate exceeded 1%, and the qualified rate was only 84.93%. After 2019, the scrap steel rate was significantly reduced and the qualified rate was significantly improved after the method of improving the rolling stability of thin-gauge high-strength steel of the present invention was adopted. After June 2019, the scrap steel rate was reduced to below 0.4%, and the qualified rate was increased to more than 94.38%. Comprehensive comparison, after the implementation of this method, the average scrap steel rate was reduced from 1% to 0.07%. There was no scrap steel from December 2019 to June 2020 and from January 2021 to July 2021. At the same time, the average qualified rate was increased from 84.93% to 94.38%.

[0070] 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 improving the rolling stability of thin-gauge high-strength steel, characterized in that: The method comprises, Before rolling, the parameters of the finishing mill are calibrated: the side guide plates are calibrated, the short stroke of the guide plates at the entrance of the finishing mill is set, and the tapping rhythm of the heating furnace is set; The short stroke setting of the guide plate on the entrance side of the finishing mill includes: The short stroke of the side guide plate head, the short stroke of the side guide plate middle and the short stroke of the side guide plate tail of the finishing mills F2, F3, F4, F5, F6 and F7 are set in sequence, and the stroke setting range is 20 to 70 mm, among which, The short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F2 are set to 20-40 mm, and the short stroke of the side guide tail is set to 40 mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F3 are set to 25-50 mm, and the short stroke of the side guide tail is set to 40 mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F4 are set to 30-60 mm, and the short stroke of the side guide tail is set to 50 mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F5 are set to 35-60 mm, and the short stroke of the side guide tail is set to 55 mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F6 are set to 40-70 mm, and the short stroke of the side guide tail is set to 60 mm; the short stroke of the side guide head and the short stroke of the side guide middle of the finishing mill F7 are set to 45-70 mm, and the short stroke of the side guide tail is set to 70 mm; Based on the calibrated parameters, the looper tension of the finishing mill is set when rolling thin-gauge high-strength steel; During the finishing rolling of the tail, the tail shape is adjusted according to the wedge value of the strip tail; When the wedge value is negative, the roll gap is tilted and adjusted in the negative direction, including: When the wedge value of the strip tail is -10 to 0, the roll gap of the F4-F7 stands is tilted to the operating side by 0.05 to 0.15 mm according to the strip shape; When the wedge value of the strip tail is -30 to -10, the roll gap of the F2-F7 stands is tilted to the operating side by 0.15 to 0.30 mm according to the strip shape; When the wedge value of the strip tail is less than -30, the roll gap is adjusted during rough rolling to control the wedge value to be less than or equal to 30, and the roll gap of the F2-F7 stands is tilted by 0.15 to 0.30 mm on the operating side. When the wedge value is positive, the roll gap is tilted and adjusted in the positive direction, including: When the wedge value of the strip tail is 0-10, the roll gap of the F4-F7 stands is tilted and the operating side is raised by 0.05-0.15mm respectively according to the strip shape; When the wedge value of the strip tail is greater than 30, the roll gap is adjusted for rough rolling to control the wedge value ≤ 30, and the roll gap tilting operation side of the F2-F7 stands is raised by 0.05 to 0.15 mm respectively.

2. A method for improving rolling stability of thin gauge high strength steel according to claim 1, characterized in that: The calibration of the side guide plate includes calibrating the center and opening of the side guide plate, wherein: Eliminate the mechanical clearance of the side guide plates, calibrate the side guide plate centering and opening with the midpoint of the mill arch as the base point, and obtain the on-site measured values ​​of the side guide plate centering and opening; Inputting the on-site measured values ​​of the side guide plate centering and opening into the calibration program; Repeat once or more to eliminate the mechanical clearance of the side guide plates, and calibrate the centering and opening of the side guide plates with the midpoint of the rolling mill arch as the base point, so that the deviation between the actual opening measured on site and the opening set by the program is ≤5mm, and the centering deviation of the side guide plates is ≤3mm.

3. A method for improving rolling stability of thin-gauge high-strength steel according to claim 2, characterized in that: The midpoint of the mill arch is measured by a tape measure.

4. The method for improving rolling stability of thin-gauge high-strength steel according to claim 1, characterized in that: Setting the tapping rhythm of the heating furnace, including: When the production thickness of the steel strip is ≤2.0mm, set the heating furnace to tap steel at 200S / piece-240S / piece. When the production thickness of the steel strip is detected to be greater than 2.0, the tapping time of the heating furnace is set to 160S / block-220S / block, wherein the production thickness of the steel strip is obtained by detecting the HMD signal at the outlet of the descaling box.

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