A method for improving the rolling stability of thin gauges in a continuous casting and rolling production line

Abstract

This invention discloses a method for improving the rolling stability of thin-gauge strips in a continuous casting and rolling production line. The method includes a thin slab rolling mill; adjusting the mill rigidity; adjusting the thickness of the intermediate strip slab; installing a width measuring instrument at the exit of the fan-shaped section of the slab; continuously comparing the measured value with the actual value; replacing the actual measured value with a preset width value when the deviation obtained from the comparison does not meet the constraint conditions; reducing the downward pressure of the roughing mill to a preset percentage of the original downward pressure; adjusting the looper tension to a preset value; and after the strip is threaded at the tail end, the mill accelerates in segments according to a preset strategy with delay time intervals based on a delayed acceleration command. This effectively reduces the occurrence of issues such as strip deviation, steel accumulation, poor coil shape, tailing, and rolling damage during the production of thin-gauge strips.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and in particular to a method for improving the rolling stability of thin-gauge steel in continuous casting and rolling production lines. Background Technology

[0002] Thin slab continuous casting and rolling technology is a major innovative technology developed in the late 1980s. From the late 1990s to the present century, this technology has been rapidly promoted and widely applied worldwide. To date, thin slab continuous casting and rolling technology has developed into a variety of distinctive production processes, such as CSP, ISP, FTSR / QSP, CEM, and ESP. In terms of production modes, it can be mainly divided into two types: intermittent rolling (single-slab rolling, semi-endless rolling) and endless rolling.

[0003] Among them, the MCCR (The Multi-mode Continuous Casting & Rolling Plant) is the world's first third-generation thin slab continuous casting and rolling production line with flexible production modes. It adopts a brand-new production line layout to realize three rolling modes: single slab, semi-endless, and endless. Its product range is wider, and its product performance and surface quality are superior. In the existing technology, the thin-gauge rolling process of the MCCR production line is a complex process involving multiple factors such as technology, equipment, and operation. Due to the large rolling force and high rolling speed, it is difficult to control the strip shape and there are problems such as uneven temperature of the strip cross section. At the same time, how to ensure the stability of strip threading under high rolling speed is also an important factor restricting the rolling of thin gauges. Summary of the Invention

[0004] This application provides a method to improve the rolling stability of thin-gauge strips in continuous casting and rolling production lines, which at least partially solves the technical problems of difficult strip shape control and uneven temperature of strip cross sections in the prior art, and effectively reduces the occurrence of deviation, steel piling, poor coil shape, tailing, and rolling damage during the production of thin-gauge strips.

[0005] Firstly, to solve the above-mentioned technical problems, embodiments of the present invention provide the following technical solutions:

[0006] A method for improving the rolling stability of thin gauges in a continuous casting and rolling production line includes:

[0007] The stiffness of the rolling mill is adjusted by controlling the stress it bears, the length of the stressed strip in the rolling mill, and the size of the stepped pads.

[0008] The thickness of the intermediate strip billet is adjusted using the built-in model of the aforementioned thin slab rolling equipment.

[0009] A width measuring instrument is installed at the exit of the fan-shaped section of the billet. The width is continuously compared with the actual measured value. When the deviation obtained from the comparison does not meet the constraint conditions, the preset width value is used to replace the actual measured value.

[0010] When the strip enters the roughing process, the pressure of the roughing mill is reduced to a preset percentage of the original pressure.

[0011] By correcting the width, frequency, and angle deviations of the rolling mill looper, the tension of the looper is adjusted to a preset value;

[0012] After the strip is threaded at the tail end, when the thickness of the strip is greater than or equal to a preset threshold, a preset delay time is set and a delay acceleration command is sent. The rolling mill accelerates in segments according to the delay time interval and a preset strategy based on the delay acceleration command.

[0013] Optionally, the above methods also include:

[0014] During headless or semi-headless rolling, after the first rolling mill throws out the steel, the second rolling mill rolls normally at a preset interval, and the third, fourth and fifth rolling mills open a preset distance based on the current roll gap.

[0015] Optionally, the above methods also include:

[0016] During the heating stage of the aforementioned thin slab rolling equipment, symmetrical coils are set on both sides of the strip and heated according to preset requirements.

[0017] Optionally, the above-mentioned heating step, which involves heating according to preset requirements, further includes:

[0018] When the strip enters the endless rolling mill, the heating power level is set and increased by one power level at a first preset interval; when a heating abnormality is detected, the heating power is gradually reduced to zero at the same Dürer interval gradient according to a preset percentage.

[0019] Optionally, any of the above-mentioned coils are arranged in a ring and parallel to the above-mentioned strip.

[0020] Optionally, the step of adjusting the thickness of the intermediate strip billet using the built-in model of the thin slab rolling equipment further includes:

[0021] Set the target value for the intermediate billet thickness, and set the intermediate billet thickness setting table according to the strip steel race layer and width and thickness layer;

[0022] During the thinning or thickening process, an intermediate billet thickness variation step table is set according to the step value of the intermediate billet thickness variation of the front and rear strip steel in the rolling plan at this time.

[0023] The intermediate billet thickness is adjusted and compensated according to the intermediate billet thickness setting table and the intermediate billet thickness variation step table.

[0024] Optionally, the step of adjusting the thickness of the intermediate strip billet using the built-in model of the thin slab rolling equipment further includes:

[0025] Check the load control logic, set constraints on the thickness change of the intermediate billet according to the strip race and thickness, and adjust the thickness change rate of the intermediate billet to the preset requirements.

[0026] Optionally, the above steps for checking the load control logic further include:

[0027] During the roughing process, the deviation of the roughing load value is calculated; the obtained deviation value is compared with the preset value, and the load control logic is checked based on the comparison result.

[0028] Optionally, the above steps for adjusting the mill stiffness by controlling the stress borne by the mill, the length of the stressed strip in the mill, and the dimensions of the stepped pads further include:

[0029] During the rolling process, when the rolling mill is not under load, the rolling mill is controlled to bear a preset pressure value.

[0030] Optionally, the above-mentioned step of setting a width measuring instrument at the exit of the fan-shaped section of the cast billet further includes:

[0031] The aforementioned width measuring instrument is equipped with a protective cover for the instrument.

[0032] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0033] By adjusting the mill rigidity and the thickness of the intermediate strip billet; installing a width measuring instrument at the exit of the fan-shaped section of the cast billet and continuously comparing it with the actual measured value, replacing the actual measured value with a preset width value when the deviation obtained from the comparison does not meet the constraint conditions; reducing the downward pressure of the roughing mill to a preset percentage of the original downward pressure; adjusting the looper tension to a preset value; and accelerating the mill in segments according to the delayed acceleration command at intervals based on a preset strategy after the strip is threaded at the tail end, this effectively reduces the occurrence of deviation, steel piling, poor coiling, tailing, and rolling damage during the production of thin-gauge strip. Attached Figure Description

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

[0035] Figure 1 A flowchart of a method for improving the rolling stability of thin gauges in a continuous casting and rolling production line is provided in this application;

[0036] Figure 2 This is a schematic diagram showing the results of the local high-point blocking rate of the strip steel in this application;

[0037] Figure 3 This is a schematic diagram of the structure of a prior art coil in this application;

[0038] Figure 4 This is a schematic diagram of the coil structure used in this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the term "setup" should be interpreted broadly. For example, it can refer to a fixed setup, a detachable setup, or an integral setup; it can refer to a mechanical setup or an electrical setup; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Unless otherwise specified, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0044] In the embodiments of this application, the following are provided: Figure 1 The method shown is for improving the rolling stability of thin-gauge slabs in a continuous casting and rolling production line, including thin slab rolling equipment, namely the MCCR (The Multi-mode Continuous Casting & Rolling Plant) third-generation thin slab continuous casting and rolling production line. The method includes steps S101 to S106:

[0045] Step S101: Adjust the mill stiffness by controlling the stress borne by the mill, the length of the stressed strip in the mill, and the size of the stepped pad.

[0046] It should be noted that mill stiffness reflects the mill's ability to resist elastic deformation caused by rolling pressure. As a crucial attribute of the mill, mill stiffness has a significant impact on the roll gap. It not only affects the overall thickness accuracy of the strip but also influences the given horizontal value of the mill due to the difference in stiffness between the two sides, posing a significant threat to production stability. Transverse stiffness directly determines the quality of the rolled strip shape, while longitudinal stiffness is crucial for controlling the longitudinal thickness of the strip. The transverse stiffness of the mill reflects its ability to maintain a constant roll gap crown against fluctuations in rolling force. Therefore, this embodiment adjusts the mill stiffness by controlling the stress borne by the mill, the length of the stressed strip in the mill, and the size of the stepped pads to enhance the roll stiffness.

[0047] Step S102: Adjust the thickness of the intermediate strip billet using the built-in model of the thin slab rolling equipment;

[0048] It should be noted that the thickness of the intermediate slab of the strip corresponds to the values ​​of subsequent operations, specifically the load distribution in roughing and the control of the mill speed after strip threading during finishing. The adjustment of the load distribution in roughing aims to prevent the thickness of the intermediate slab from changing too much and exceeding the threshold, which would cause abnormal load distribution in roughing. The control of the mill speed aims to prevent strip warping and sleeve lifting.

[0049] Step S103: A width measuring instrument is set at the exit of the fan-shaped section of the billet. The instrument is continuously compared with the actual measured value. When the deviation obtained by the comparison does not meet the constraint conditions, the preset width value is used to replace the actual measured value.

[0050] It should be noted that different steel grades will have different exit widths before casting begins (this data is based on a large number of actual measurements). By continuously comparing with the actual measurement data, the exit width of each steel grade can be determined. When the actual measurement value deviates significantly, the actual measurement value is not adopted, and the given width value is used directly to replace the actual measurement value.

[0051] Step S104: When the strip enters the roughing process, the downward pressure of the roughing mill is reduced to a preset percentage of the original downward pressure.

[0052] It should be noted that when strip enters the roughing mill, the larger the reduction in the first stand, the faster the internal structure recrystallizes, resulting in finer original austenite grains and better performance for subsequent strip production. Therefore, the roughing mill uses a relatively large reduction. However, in actual production, it was found that as the drawing speed gradually increases, a larger reduction in the roughing mill has a significant impact on the matching between the roughing and finishing mills (mainly at the moment of reduction). Especially in the mixing stage (the last piece of the previous heat and the first piece of the next heat), due to the uneven internal structure, continuing to use a large reduction will have a significant impact on rolling stability. Therefore, in this embodiment, the tundish tonnage is reduced from 50 tons to 43 tons in the continuous rolling mode, and a "soft reduction" is adopted for the mixing section. The so-called soft reduction is that, relative to the original reduction, the reduction used is 70% of the original (i.e., the preset percentage). This allows for better connection and matching of the internal structure of the mixing zone and the production between the upstream and downstream stands on the production line.

[0053] Step S105: Adjust the tension of the looper to a preset value by correcting the width, frequency and angle deviations of the rolling mill looper;

[0054] It should be noted that looper tension control is one of the key parameters for the stable operation of strip steel between stands. The correction of width and frequency aims to compensate for width discrepancies, specifically by increasing the dead zone for width adjustment. That is, the width difference is reduced from 7.0 mm to 5.0 mm, and the frequency is correspondingly reduced. The correction of angle deviation aims to adjust the flow rate matching of strip steel between adjacent stands. During control, the looper tension and angle ensure a smooth transition of strip steel between stands. By correcting the looper tension and loop amount, the looper control angle is maintained between 19-22° when rolling thin strip steel.

[0055] In step S106, after the strip is threaded at the tail end, when the strip thickness is greater than or equal to a preset threshold, a preset delay time is set and a delay acceleration command is sent. The rolling mill accelerates in segments according to the delay acceleration command, with the delay time as the interval and according to the preset strategy.

[0056] It should be noted that the current rolling strategy for thin strips employs a speed-increasing rolling approach. After the F5 finishing mill completes strip threading, the mill control system increases the speed to meet the target final rolling temperature. To ensure stable threading, a low-speed threading and high-speed rolling strategy is used for thin strip rolling. After low-speed threading, the strip head temperature is lower than the target temperature. If the current F5 speed-increasing strategy is followed, the rolling speed will rapidly increase in a short period, causing strip warping and slippage, which is detrimental to rolling stability. Therefore, this embodiment calculates the strip acceleration strategy based on different thickness intervals. When the strip thickness H ≤ 1.4mm, a delayed speed-increasing command is issued to the mill, which then increases the speed in stages according to the delay information to ensure stability during threading. When H > 1.4mm, the existing speed-increasing mode is used for threading. This improves the rolling stability of thin strips, with the proportion of strips below 1.5mm consistently above 55%, and the blocking rate caused by local high points in the strip decreases significantly. Figure 2 As shown.

[0057] Furthermore, the method also includes: during headless or semi-headless rolling, after the first rolling mill throws out the steel at a preset interval, the second rolling mill rolls normally, and the third, fourth and fifth rolling mills open a preset distance based on the current roll gap.

[0058] It should be noted that this step addresses the situation where the strip tail strikes the rolls and side guides during the finishing mill stand's strip throwing operation when rolling thin strips, causing roll marks or other damage to the rolls and significantly impacting coiling. Existing technology uses the maximum roll gap when the tail shear point passes through the F2 mill to prevent damage to the rolls caused by the strip tail throwing. However, this results in the strip tail needing to be cut off for 100m (40m for abnormal thickness, 60m for abnormal temperature), greatly affecting the yield. Therefore, this embodiment adopts a method where, at the end of endless or semi-endless rolling, approximately 2 seconds after the F1 mill throws the strip, the F2 mill rolls normally, the F3 mill opens the roll gap by 30mm from the current gap, the F4 mill opens it by 35mm, and the F5 mill opens it by 40mm.

[0059] Furthermore, the method also includes: during the heating stage of the thin slab rolling equipment, symmetrical coils are set on both sides of the strip and heated according to preset requirements.

[0060] It should be noted that induction heating is used in rolling equipment, which can be divided into longitudinal magnetic flux induction heating and transverse magnetic flux induction heating. For example... Figure 3As shown, this is the coil arrangement for longitudinal flux induction heating. The coils surround the strip, and the eddy currents induced by the alternating magnetic flux are parallel to the cross-section of the strip. The Joule heating of the strip is utilized by the eddy currents. However, when using longitudinal flux induction heating to heat the strip, a very high frequency is required. When the ratio of thickness to penetration depth is not large, even increasing the heating frequency and current cannot achieve the required temperature. Therefore, this embodiment uses... Figure 4 The coils shown are used for induction heating. During induction heating, the magnetic flux generated by the alternating currents in the same direction in the two symmetrically placed coils is perpendicular to the surface of the strip, and the eddy currents are parallel to the strip. There is no problem of mutual cancellation, so the shortcomings of longitudinal magnetic flux induction heating can be avoided.

[0061] Furthermore, the heating step, which is carried out according to preset requirements, also includes:

[0062] When the strip enters the endless rolling mill, the heating power level is set and increased by one power level at a first preset interval; when a heating abnormality is detected, the heating power is gradually reduced to zero at the same Dürer interval gradient according to a preset percentage.

[0063] It should be noted that during the endless rolling process, all nine sets of induction heater carriages are simultaneously brought online and pressed down to the specified gap, set at 184mm. The heater output power is set at multiple levels: 400kW, 600kW, 800kW, and 1000kW per unit. The power level is increased one level at a time, one minute apart, until reaching 1000kW (total power 2000kW). During heating, if any abnormality is detected in the heater (e.g., inability to heat or excessive temperature), the heater power is gradually reduced to 0 in 20% increments. This adjustment of the induction heater power improves the uniformity of the strip cross-section temperature. Any coil is arranged in a ring, parallel to the strip.

[0064] Furthermore, the step of adjusting the thickness of the intermediate slab of the strip steel using the built-in model of the thin slab rolling equipment also includes: setting a target value for the thickness of the intermediate slab, and setting an intermediate slab thickness setting table according to the strip steel type and width-thickness layer; during the thinning or thickening process, setting an intermediate slab thickness change step table according to the step value of the change in intermediate slab thickness of the front and rear coils of strip steel in the rolling plan at this time; and compensating for and adjusting the thickness of the intermediate slab according to the intermediate slab thickness setting table and the intermediate slab thickness change step table.

[0065] It should be noted that for the compensation of intermediate slab thickness, the intermediate slab thickness setting compensation value can be adjusted in real time according to production conditions to modify the intermediate slab thickness setting. The adjustment range has been expanded from ±1mm to ±2mm. Specifically: the intermediate slab thickness setting table sets the target value of the intermediate slab thickness, which is set according to the steel grade and width-thickness grade. For example, for steel grade Q235B, with a width of 1250mm and a thickness of 1.0mm, the corresponding intermediate slab thickness is 9.3mm. The intermediate slab thickness variation step table determines the step value of the intermediate slab thickness variation in the preceding and following coils of strip during the thinning or thickening process. It is divided according to the finishing mill exit thickness grade and steel grade; the intermediate slab thickness setting value is equal to the intermediate slab thickness setting value of the previous coil plus the intermediate slab thickness variation step value of the current coil. It should be noted that the intermediate slab thickness variation step value of the current coil corresponds to a negative value in the intermediate slab thickness variation table column during thinning and a positive value in the intermediate slab thickness variation step table column during thickening.

[0066] Furthermore, the step of adjusting the thickness of the intermediate slab of the strip steel using the built-in model of the thin slab rolling equipment also includes: checking the load control logic, setting constraints on the thickness change of the intermediate slab according to the strip steel type and thickness, and adjusting the thickness change rate of the intermediate slab to the preset requirements.

[0067] It should be noted that after checking the load control logic, the intermediate billet thickness is adjusted according to the strip type and thickness to keep the rate of change of the intermediate billet thickness within the preset range, so as to avoid large changes in the intermediate billet thickness, which would cause abnormal load distribution in the roughing mill.

[0068] Furthermore, the steps for checking the load control logic also include: calculating the deviation of the roughing load value during the roughing process; comparing the obtained deviation value with the preset value; and checking the load control logic based on the comparison results.

[0069] It should be noted that existing load checks simply add an AGC command to the loop and adjust the load based on the returned actual load value. This embodiment adds an extra step: first, it calculates the deviation of the current load. If the load deviation is within a reasonable range, it proves that the currently adopted load value is reasonable. Specifically, an AGC command is added to the load control loop of the control system; the deviation value is calculated in the load control loop of the control system; the deviation value in the control system is compared with the preset value to verify whether the calculated value of the load loop is accurate, and an error within 1% is considered accurate.

[0070] Furthermore, the step of adjusting the mill stiffness by controlling the stress borne by the mill, the length of the stressed strip in the mill, and the size of the stepped pads also includes: controlling the mill to bear a preset pressure value when the mill is not under load during the rolling process.

[0071] It should be noted that during the rolling process, when the rolling mill is not under load, it is not in a stressed state. This results in a significant increase in the deformation of the rolling mill when strip passes through, leading to a decrease in the mill's rigidity. Currently, when the rolling mill is not rolling strip, it is pre-stressed, which greatly reduces the deformation of the mill during actual rolling, thereby improving the mill's rigidity.

[0072] Furthermore, the step of setting a width measuring instrument at the exit of the fan-shaped section of the billet also includes: setting a protective cover for the width measuring instrument on the width measuring instrument.

[0073] It should be noted that since the temperature of the billet at the exit of the fan-shaped section is above 1000℃, water vapor and iron scale may interfere with the measurement data, causing deviations. To prevent this from happening, a protective cover is added to the width measuring instrument.

[0074] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0077] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for improving the stability of thin gauge rolling in a continuous casting and rolling line, comprising a thin slab rolling plant, characterized by, The method includes: The stiffness of the rolling mill is adjusted by controlling the stress it bears, the length of the stressed strip in the rolling mill, and the size of the stepped pads. The thickness of the intermediate strip billet is adjusted using the built-in model of the thin slab rolling equipment. A width measuring instrument is installed at the exit of the fan-shaped section of the billet. The width is continuously compared with the actual measured value. When the deviation obtained by the comparison does not meet the constraint conditions, the preset width value is used to replace the actual measured value. When the strip enters the roughing process, the pressure of the roughing mill is reduced to a preset percentage of the original pressure. By correcting the width, frequency, and angle deviations of the rolling mill looper, the tension of the looper is adjusted to a preset value; After the strip is threaded at the tail end, when the strip thickness is greater than or equal to a preset threshold, a preset delay time is set and a delay acceleration command is sent. The rolling mill accelerates in segments according to the preset delay time and a preset strategy based on the delay acceleration command. The method further includes: During headless or semi-headless rolling, after the first rolling mill throws out the steel, the second rolling mill rolls normally at a preset interval, and the third, fourth and fifth rolling mills open a preset distance based on the current roll gap.

2. The method of claim 1, wherein, The method further includes: During the heating stage of the thin slab rolling equipment, symmetrical coils are set on both sides of the strip and heated according to preset requirements.

3. The method of claim 2, wherein, The step of heating according to preset requirements further includes: When the strip enters the endless rolling process, a heating power level is set and increased by one power level at a first preset interval; when a heating abnormality is detected, the heating power is gradually reduced to zero at the same Dürer interval gradient according to a preset percentage.

4. The method of claim 2, wherein, Each of the coils is arranged in a ring and parallel to the strip.

5. The method of claim 1, wherein, The step of adjusting the thickness of the intermediate strip billet using the built-in model of the thin slab rolling equipment further includes: Set the target value for the intermediate billet thickness, and set the intermediate billet thickness setting table according to the strip steel race layer and width and thickness layer; During the thinning or thickening process, an intermediate billet thickness variation step table is set according to the step value of the intermediate billet thickness variation of the front and rear strip steel in the rolling plan at this time. The intermediate billet thickness is compensated and adjusted according to the intermediate billet thickness setting table and the intermediate billet thickness variation step table.

6. The method as described in claim 1, characterized in that, The step of adjusting the thickness of the intermediate strip billet using the built-in model of the thin slab rolling equipment further includes: Check the load control logic, set constraints on the thickness change of the intermediate billet according to the strip race and thickness, and adjust the thickness change rate of the intermediate billet to the preset requirements.

7. The method as described in claim 6, characterized in that, The step of checking the load control logic further includes: During the roughing process, the deviation of the roughing load value is calculated; the obtained deviation value is compared with the preset value, and the load control logic is checked based on the comparison result.

8. The method as described in claim 1, characterized in that, The step of adjusting the mill stiffness by controlling the stress borne by the mill, the length of the stressed strip in the mill, and the size of the stepped pads further includes: During the rolling process, when the rolling mill is not under load, the rolling mill is controlled to bear a preset pressure value.

9. The method as described in claim 1, characterized in that, The step of installing a width measuring instrument at the exit of the fan-shaped section of the billet further includes: The width measuring instrument is equipped with a protective cover.

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