Plate strip asymmetric local high point regulation method based on rough-precision combined rolling

Abstract

The plate strip asymmetric local high point regulation method based on rough-precision rolling combined rolling belongs to the field of metallurgical machinery and rolling. The method first acquires the size and position of the plate strip asymmetric local high point at the precision rolling outlet; calculates the leveling influence coefficient according to the size and position of the local high point; calculates the leveling value according to the leveling influence coefficient for the last pass of the last stand of rough rolling, and levels the head of the next plate strip; when the tension is established between the plate strip and the coiling after the plate strip, the corresponding leveling value is calculated according to the leveling influence coefficient for each stand of the precision rolling, and the plate strip body is leveled. The application solves the problem that the plate strip asymmetric local high point is caused by the fact that the plate strip deviates to one side of the roller, the roller on the side is worn too fast, and the plate strip asymmetric local high point problem in the actual production process is improved, the rolling kilometers are prolonged, the qualified rate is improved, and the economic loss caused by the plate shape not meeting the standards is reduced.

Description

Technical field:

[0001] The present invention belongs to the field of metallurgical machinery and rolling, and in particular relates to a method for controlling asymmetric local high points of a plate and strip based on roughing-finishing combined rolling. Background technology:

[0002] Hot rolling is generally used to produce plate and strip steel products. This process includes billet heating, rough rolling, finishing rolling, cooling, and coiling. It features a short process, low energy consumption, and high production efficiency, making it widely used in the production of hot-rolled coils. During the hot rolling process, the strip edge and the rollers create a harmful contact area, which causes uneven wear and forms a "cat's ear" phenomenon, further creating local high spots on the strip. When the strip deviates, the force on the rollers on the offset side increases, exacerbating the uneven wear caused by the harmful contact area. As the number of rolled coils increases, the local high spots on the offset side gradually become more pronounced, ultimately forming asymmetric local high spots.

[0003] In the existing technology, in order to overcome the asymmetric local high points caused by edge wear and ensure the cross-sectional profile quality of the product, on the one hand, the offset phenomenon is corrected by improving the uneven pressure of the plate and strip. Generally, the asymmetric local high points of the plate and strip are alleviated by adjusting the center line of the plate and strip during operation. However, due to differences in workers' experience and inconsistent operating standards, the adjustment effect is relatively low and the local high points cannot be completely eliminated. On the other hand, the wear problem is solved by shortening the number of production blocks of the rolling unit and replacing the working rolls. However, this method not only causes the production line to stop, reduces production efficiency and output, but also increases the number of roll changes and increases production costs. Summary of the invention:

[0004] In order to solve the above problems, the present invention provides a method for controlling the asymmetric local high points of plates and strips based on roughing-finishing combined rolling. First, the size and position of the asymmetric local high points of the current finishing outlet plate and strip are obtained, and the leveling influence coefficient is calculated according to the size and position of the local high points. The leveling value of the last pass of the roughing last stand is calculated according to the leveling influence coefficient to level the head of the next plate and strip. After the tension relationship between the plate and strip is established between finishing and coiling, each stand upstream of the finishing rolling calculates the corresponding leveling value according to the leveling influence coefficient to level the plate and strip body. In this way, the asymmetric local high points of the plate and strip are accurately controlled and adjusted by calculating the leveling, thereby reducing the error of manual experience adjustment, improving the rolling stability, optimizing the cross-sectional shape, and improving the plate shape quality.

[0005] In order to achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:

[0006] A method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling comprises the following steps:

[0007] Step S1, obtaining the size and position of the asymmetric local high point of the first strip at the finishing rolling outlet.

[0008] In this step, the size of the asymmetric local high point is calculated by the value of the high point exceeding the plate plane; the position of the asymmetric local high point includes the transmission side and the operating side, and it is sufficient to determine which side the high point is located on.

[0009] Step S2: Calculate the leveling influence coefficient according to the size and position of the local high point of the first strip.

[0010] In this step, the formula for the leveling influence coefficient is as follows;

[0011]

[0012] In formula (1), δ represents the leveling influence coefficient, S represents the asymmetric local high point value of the plate strip, and k is the multiplication coefficient, which is usually a constant. Preferably, k is in the range of 1.4-1.6, and optimally, k is 1.5.

[0013] In this step, a linear function is used to calculate the leveling influence coefficient, which can provide a simple, intuitive, easy-to-control and easy-to-adjust method.

[0014] Step S3, calculating the leveling value of the second strip head in the last pass of the rough rolling final stand according to the leveling influence coefficient.

[0015] In this step, the formula for calculating the leveling value of the strip head based on the adjustment influence coefficient is as follows:

[0016]

[0017] In formula (2), A R is the leveling value of the second strip head in the last pass of the roughing mill stand, and |A R |≤50μm. If the calculated value is greater than 50μm, 50μm is assigned directly. N is the number of upstream stands in the finishing mill. This formula uses |δ| / δ to determine the roughing mill leveling direction. A logarithmic function is used to ensure that the strip head leveling value for the final pass in the roughing mill begins at the origin. As |δ| increases, the logarithmic function also ensures that the leveling value increment does not increase too much. The number of upstream stands is generally 4, meaning that the upstream stands are F1-F4.

[0018] Step S4, leveling the last-pass roller of the roughing stand according to the leveling value; when the leveling value is positive, the transmission side of the last-pass roughing stand presses down the absolute value of the leveling value, and the operating side lifts the absolute value of the leveling value to level the head of the strip; when the leveling value is negative, the operating side of the last-pass roughing stand presses down the absolute value of the leveling value, and the transmission side lifts the absolute value of the leveling value to level the head of the second strip.

[0019] In this step, according to the calculated leveling value A R By adjusting the rollers, the strip head of the final roughing stand is leveled. From formula (2), it can be seen that when the leveling value is positive, the transmission side of the final roughing stand is pressed down |A R |, operating side lift |A R |, level the strip head; when the leveling value is negative, the roughing mill stand last pass operating side presses down |A R |, transmission side lift|A R |, thereby leveling the second plate strip head.

[0020] Step S5: calculating the leveling value of each upstream stand of the finishing rolling mill according to the leveling influence coefficient.

[0021] In this step, the formula for calculating the leveling value of the strip head of each stand upstream of the finishing rolling mill according to the leveling influence coefficient is as follows:

[0022]

[0023] In formula (3), A F [n] represents the leveling value of the nth upstream finishing stand, and |A F [n]|≤10(N+1-n)μm; if the calculated value is greater than 10(N+1-n)μm, directly assign the value to 10(N+1-n)μm.

[0024] In this step, the control amount of each stand upstream of the finishing rolling mill calculated according to formula (3) is gradually reduced, which can achieve more precise control of the deviation of the strip.

[0025] Step S6, when the second strip enters the finishing rolling, after the tension is established between the finishing rolling and the coiling, each frame upstream of the finishing rolling is leveled according to the leveling value of each frame upstream of the finishing rolling; when the leveling value is positive, the transmission side of each frame upstream of the finishing rolling presses down the corresponding absolute value of the leveling value, and the operating side lifts the corresponding absolute value of the leveling value; when the leveling value is negative, the operating side of each frame upstream of the finishing rolling presses down the corresponding absolute value of the leveling value, and the transmission side lifts the corresponding absolute value of the leveling value.

[0026] In this step, according to the calculated leveling value A F [n], by adjusting the rollers, when the leveling value is positive, the transmission side of each frame upstream of the finishing rolling mill is pressed down|A F [n]|, operating side lift|A F [n]|, level the strip body entering the current finishing mill.

[0027] As can be seen from the above scheme, the method for controlling asymmetric local high points of strips based on combined roughing and finishing rolling described in the embodiment of the present invention first obtains the size and position of the asymmetric local high points of the strip at the finishing exit; calculates the leveling influence coefficient based on the size and position of the local high points; calculates the leveling value based on the leveling influence coefficient in the last pass of the roughing end stand, and leveled the head of the next strip; after the strip has established tension between finishing and coiling, each stand upstream of the finishing roll calculates the corresponding leveling value based on the leveling influence coefficient, and leveled the strip body. The present invention effectively solves the problem of asymmetric local high points in the strip due to the strip deviating to one side of the roller, causing the roller on that side to wear too quickly, thereby improving the plate shape problem of asymmetric local high points in the actual production process, improving the qualified rate, extending the rolling mileage, and reducing the economic losses caused by substandard plate shape problems.

[0028] Of course, it is not necessary to achieve all of the advantages described above simultaneously in order to implement any product or method of the present invention. Description of the drawings:

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a flow chart of the method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to Example 1 of the present invention;

[0031] Figure 2 is the shape data of the first strip in Example 1 of the present invention;

[0032] Figure 3 It is the plate shape data of the second plate strip in Example 1 of the present invention. Specific implementation method:

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. It should be noted that the embodiments of the present invention and the features in the embodiments can also be combined with each other in the absence of conflict.

[0034] It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the description of the present invention, the terms "first," "second," "third," "fourth," etc. are used only to distinguish the description and are not to be understood as indicating or implying relative importance.

[0035] Example 1

[0036] Example 1 of the present invention provides a method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling. Figure 1 As shown, the method includes the following steps:

[0037] Step S1: Obtain the size and location of the asymmetric local high point on the first strip at the finishing mill exit. For example, in a hot rolling production line at a certain mill, an asymmetric local high point was detected when producing 1250mm wide 50PG195 silicon steel. The mill's finishing mill consists of four finishing stands upstream.

[0038] like Figure 2 As shown, an asymmetric local high point was detected in the plate strip, the height value S representing the size of the high point was 22 μm, and the high point appeared on the transmission side.

[0039] Step S2: Calculate the leveling influence coefficient according to the size and position of the local high point of the first strip. Calculate the leveling influence coefficient δ according to formula (1):

[0040] δ=Sk=22×1.5=33

[0041] The leveling influence coefficient δ is obtained to be 33, and the number of upstream stands of finishing rolling is N=4.

[0042] Step S3, calculating the leveling value of the second strip head of the last pass of the rough rolling mill stand according to the leveling influence coefficient:

[0043]

[0044] In step S4, the final-pass rollers of the final roughing stand are leveled based on the leveling value. When the leveling value is positive, the final-pass transmission side of the final roughing stand is depressed by the absolute value of the leveling value, while the operating side is elevated by the absolute value of the leveling value, leveling the strip head. When the leveling value is negative, the final-pass operating side of the final roughing stand is depressed by the absolute value of the leveling value, while the transmission side is elevated by the absolute value of the leveling value, leveling the second strip head. Based on the calculated leveling value, the final-pass transmission side of the final roughing stand is depressed by 36.0 μm, while the operating side is elevated by 36.0 μm, leveling the strip head.

[0045] Step S5, calculating the leveling value of each stand upstream of the finishing rolling mill according to the leveling influence coefficient:

[0046]

[0047] In step S6, when the second strip enters the finishing mill and tension is established between the finishing mill and the coiling mill, each of the upstream stands of the finishing mill is leveled according to the leveling value of each of the upstream stands of the finishing mill. When the leveling value is positive, the transmission side of each upstream stand of the finishing mill is pressed down by the corresponding absolute value of the leveling value, and the operating side is raised by the corresponding absolute value of the leveling value. When the leveling value is negative, the operating side of each upstream stand of the finishing mill is pressed down by the corresponding absolute value of the leveling value, and the transmission side is raised by the corresponding absolute value of the leveling value. Specifically, the upstream L1 stand presses the transmission side down by 31.97μm and raises the operating side by 31.97μm; the upstream L2 stand presses the transmission side down by 23.98μm and raises the operating side by 23.98μm; the upstream L3 stand presses the transmission side down by 15.99μm and raises the operating side by 15.99μm; and the upstream L4 stand presses the transmission side down by 7.99μm and raises the operating side by 7.99μm. When the strip enters the corresponding finishing mill stand, the strip body is leveled through the above-mentioned regulation of the stand.

[0048] After the above leveling, the strip enters the final stand of the finishing rolling mill to complete the finishing rolling. The strip obtained after the exit is as follows: Figure 3 As shown, it can be found that the problem of asymmetric local high points of the plate and strip has been improved, and no obvious local high points appear. At this point, the regulation of asymmetric local high points of the plate and strip has been completed.

[0049] It can be seen from the above technical solutions that the method for controlling asymmetric local high points of plates and strips based on combined roughing and finishing rolling provided by the embodiment of the present invention first obtains the size and position of the asymmetric local high points of the finished strip at the exit; calculates the leveling influence coefficient based on the size and position of the local high points; calculates the leveling value based on the leveling influence coefficient for the last pass of the roughing last stand, and leveled the head of the next plate and strip; after the plate and strip have established tension between finishing and coiling, each stand upstream of finishing calculates the corresponding leveling value based on the leveling influence coefficient, and leveled the plate and strip body. The present invention effectively solves the problem of asymmetric local high points in the plate and strip due to the strip deviating to one side of the roller, causing the roller on that side to wear too quickly, thereby improving the plate shape problem of asymmetric local high points in the actual production process, improving the qualified rate, extending the rolling mileage, and reducing the economic losses caused by substandard plate shape problems.

[0050] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. It is not intended to limit the scope of the invention to be protected, but merely represents a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling, characterized in that: The method comprises the following steps: Obtain the size and position of the asymmetric local high point of the first strip at the finishing exit; Calculate the leveling influence coefficient based on the size and position of the local high point of the first plate strip; Calculate the leveling value of the second strip head in the last pass of the roughing mill stand according to the leveling influence coefficient; According to the leveling value, the last pass roller of the roughing rolling stand is leveled; when the leveling value is positive, the transmission side of the last pass of the roughing rolling stand is pressed down by the absolute value of the leveling value, and the operating side is raised by the absolute value of the leveling value to level the head of the strip; when the leveling value is negative, the operating side of the last pass of the roughing rolling stand is pressed down by the absolute value of the leveling value, and the transmission side is raised by the absolute value of the leveling value to level the head of the second strip; Calculate the leveling value of each stand upstream of the finishing mill according to the leveling influence coefficient; When the second strip enters the finishing rolling mill and the tension is established between the finishing rolling mill and the coiling mill, the upstream stands of the finishing rolling mill are leveled according to the leveling values ​​of the upstream stands of the finishing rolling mill; When the leveling value is positive, the transmission side of each upstream frame of the finishing rolling mill is pressed down by the corresponding absolute value of the leveling value, and the operating side is lifted up by the corresponding absolute value of the leveling value; when the leveling value is negative, the operating side of each upstream frame of the finishing rolling mill is pressed down by the corresponding absolute value of the leveling value, and the transmission side is lifted up by the corresponding absolute value of the leveling value.

2. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 1, characterized in that: The size of the asymmetric local high point is calculated by the value of the high point exceeding the plane of the plate strip; the position of the asymmetric local high point includes the transmission side and the operating side.

3. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 2, characterized in that: The formula of the leveling influence coefficient is as follows: （1） In formula (1), δ represents the leveling influence coefficient, S represents the asymmetric local high point value of the plate strip, k is the gain coefficient.

4. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 3, characterized in that: k The value range is 1.4-1.

6.

5. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 3, characterized in that: The formula for calculating the leveling value of the second strip head in the last pass of the roughing mill stand according to the leveling influence coefficient is as follows: （2） In formula (2), is the leveling value of the second strip head in the last pass of the roughing mill stand, and ≤50μm, if the calculated value is greater than 50μm, it will be directly assigned as 50μm; N is the number of upstream stands for finishing rolling.

6. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 5, characterized in that: The number of the upstream finishing rolling stands is 4.

7. The method for controlling asymmetric local high points of a plate and strip based on combined roughing and finishing rolling according to claim 5, characterized in that: The formula for calculating the leveling value of the strip head of each stand upstream of the finishing rolling mill according to the leveling influence coefficient is as follows: （3） In formula (3), represents the leveling value of the nth upstream finishing stand, and ≤10( N +1- n )μm; if the calculated value is greater than 10( N +1- n )μm, then directly assign a value of 10( N +1- n )μm.

Images