Plate strip asymmetric local high point regulation and control method based on rough-finish rolling combined rolling

Abstract

The embodiment of the invention discloses a plate strip asymmetric local high point regulation and control method based on rough rolling and finish rolling combined rolling, and belongs to the field of metallurgical machinery and rolling. The method comprises the steps that firstly, the size and position of asymmetric local high points of a finish rolling outlet plate strip are obtained; calculating a leveling influence coefficient according to the size and the position of the local high point; the leveling value is calculated according to the leveling influence coefficient in the last pass of the rough rolling last rack, and the head of the next plate strip is leveled; and after tension is established between finish rolling and coiling of the plate strip, corresponding leveling values are calculated by all racks at the upstream of finish rolling according to the leveling influence coefficients, and the plate strip body is leveled. According to the method, the problem that asymmetric local high points appear on the plate strip due to the fact that the plate strip deviates to one side of the roller and the roller on the side is abraded too fast is solved, the plate shape problem that the asymmetric local high points appear in the actual production process is solved, the rolling kilometers are increased, the percent of pass is increased, and economic losses caused by the problem that the plate shape does not reach the standard are reduced.

Description

Technical field:

[0001] The 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. The process includes billet heating, rough rolling, finishing rolling, cooling and coiling. It has the characteristics of short process, low energy consumption and high production efficiency, and is widely used in the production of hot rolled coils. During the hot rolling of plates and strips, the harmful contact area between the edge of the plate and the roller will cause uneven wear, thus forming the "cat ear" phenomenon, and then produce local high points on the plate and strip; when the plate and strip deviates, the force on the roller on the offset side increases, and the uneven wear caused by the harmful contact area increases. With the increase in the number of rolled coils, the local high point of the roller on the offset side gradually appears and becomes more and more significant, and finally forms an asymmetric local high point.

[0003] In the prior art, 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 deviation 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 worker 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 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 finished-rolled outlet plates and strips are obtained, and the leveling influence coefficient is calculated according to the size and position of the local high points. The last pass of the roughing last stand calculates the leveling value according to the leveling influence coefficient to level the head of the next plate and strip. After the tension relationship between the finishing and coiling of the plate and strip is established, each upstream stand of the finishing rolling calculates the corresponding leveling value according to the leveling influence coefficient to level the plate and strip body, thereby accurately controlling and adjusting the asymmetric local high points of the plate and strip by calculating the leveling, 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 object, the technical solution adopted by the embodiment of the present invention is as follows:

[0006] A method for controlling asymmetric local high points of a plate and strip based on roughing-finishing combined 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 exit.

[0008] In this step, 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, and it is sufficient to determine which side the high point is located.

[0009] Step S2, calculating 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 increase 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 adjust method.

[0014] Step S3, calculating the leveling value of the second strip head of 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 according to 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, it is directly assigned to 50μm; N is the number of upstream stands for finishing. The formula obtains the leveling direction of the roughing mill by |δ| / δ, and uses a logarithmic function to ensure that the leveling value of the strip head of the last pass of the roughing mill starts from the origin. When |δ| increases, the logarithmic function can ensure that the increment of the leveling value will not be too large. The number of upstream stands is generally 4, that is, the upstream stands are F1-F4 stands.

[0018] Step S4, according to the leveling value, level the last-pass roller of the rough rolling stand; when the leveling value is positive, the last-pass transmission side of the rough rolling 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 plate and strip; when the leveling value is negative, the last-pass operating side of the rough rolling 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 plate and 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 last pass operating side of the roughing mill stand is pressed down |A R |, transmission side lift|A R |, thereby leveling the second plate with the head.

[0020] Step S5, calculating the leveling value of each upstream rack 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 mill stand, and |A F [n]|≤10(N+1-n)μm; if the calculated value is greater than 10(N+1-n)μm, it is directly assigned as 10(N+1-n)μm.

[0024] In this step, the control amount of each rack 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 plate and 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 absolute value of the corresponding leveling value, and the operating side lifts the absolute value of the corresponding leveling value; when the leveling value is negative, the operating side of each frame upstream of the finishing rolling presses down the absolute value of the corresponding leveling value, and the transmission side lifts the absolute value of the corresponding 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 plate and strip body entering the current finishing mill.

[0027] It can be seen from the above scheme that the asymmetric local high point control method of the plate and strip based on the rough-finishing combined rolling described in the embodiment of the present invention first obtains the size and position of the asymmetric local high point of the plate and strip at the finishing exit; calculates the leveling influence coefficient according to the size and position of the local high point; the last pass of the rough rolling last stand calculates the leveling value according to the leveling influence coefficient, and leveling the head of the next plate and strip; when the plate and strip establishes tension between the finishing and coiling, each frame upstream of the finishing rolling calculates the corresponding leveling value according to the leveling influence coefficient, and leveling 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 plate and strip deviating to one side of the roller, causing the roller on that side to wear too quickly, improves the plate shape problem of asymmetric local high points in the actual production process, improves the qualified rate, extends the rolling mileage, and reduces the economic losses caused by the plate shape problem that does not meet the standards.

[0028] Of course, it is not necessary to achieve all of the advantages described above at the same time 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 drawings required for use in the description of the embodiments will be briefly introduced below. 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 It is a flow chart of the asymmetric local high point control method of a plate and strip based on roughing-finishing combined rolling as described in Example 1 of the present invention;

[0031] Figure 2 is the shape data of the first strip in Embodiment 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 drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here 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 without conflict.

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

[0035] Example 1

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

[0037] Step S1, obtaining the size and position of the asymmetric local high point of the first strip at the finishing exit. Taking a hot rolling production line of a certain factory as an example, when producing 50PG195 silicon steel with a width of 1250mm, an asymmetric local high point of the strip is detected; and there are 4 finishing stands upstream of the finishing mill group of the factory.

[0038] like Figure 2 As shown, asymmetric local high points were detected in the strip, the height value S representing the size of the high points was 22 μm, and the high points 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 plate 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 final stand according to the leveling influence coefficient:

[0043]

[0044] Step S4, according to the leveling value, the last pass roller of the roughing mill stand is leveled; when the leveling value is positive, the last pass transmission side of the roughing mill 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 last pass operating side of the roughing mill 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. According to the calculated leveling value, the last pass transmission side of the roughing mill stand is pressed down by 36.0μm, and the operating side is raised by 36.0μm to level the head of the strip.

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

[0046]

[0047] 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 is pressed down by the absolute value of the corresponding leveling value, and the operating side is raised by the absolute value of the corresponding leveling value; when the leveling value is negative, the operating side of each frame upstream of the finishing rolling is pressed down by the absolute value of the corresponding leveling value, and the transmission side is raised by the absolute value of the corresponding leveling value. Specifically, the upstream L1 frame presses the transmission side down by 31.97μm and raises the operating side by 31.97μm; the upstream L2 frame presses the transmission side down by 23.98μm and raises the operating side by 23.98μm; the upstream L3 frame presses the transmission side down by 15.99μm and raises the operating side by 15.99μm; the upstream L4 frame 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-mentioned leveling, the strip enters the final stand of the finishing rolling mill to complete the finishing rolling. The strip obtained after exiting 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 scheme that the asymmetric local high point control method of the plate and strip based on the rough-finishing combined rolling provided by the embodiment of the present invention first obtains the size and position of the asymmetric local high point of the plate and strip at the finishing exit; calculates the leveling influence coefficient according to the size and position of the local high point; the last pass of the rough rolling last stand calculates the leveling value according to the leveling influence coefficient, and level the head of the next plate and strip; when the plate and strip establishes tension between the finishing and coiling, each stand upstream of the finishing rolling calculates the corresponding leveling value according to the leveling influence coefficient, and level 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 plate and strip deviating to one side of the roller, causing the roller on that side to wear too quickly, improves the plate shape problem of asymmetric local high points in the actual production process, improves the qualified rate, extends the rolling mileage, and reduces the economic losses caused by the plate shape problem that does not meet the standards.

[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 claimed for protection, but only represents the 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 solution 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 creative work belong to 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 roughing-finishing combined 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 according to the size and position of the local high point of the first plate strip; Calculate the leveling value of the second strip head of the last pass of the roughing final stand according to the leveling influence coefficient; According to the leveling value, the last pass roller of the rough rolling last stand is leveled; when the leveling value is positive, the last pass transmission side of the rough rolling last 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 plate strip; when the leveling value is negative, the last pass operating side of the rough rolling last 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 plate strip; Calculate the leveling value of each stand upstream of the finishing rolling mill according to the leveling influence coefficient; When the second strip enters the finishing rolling, after the tension is established between the finishing rolling and the coiling, the upstream stands of the finishing rolling are leveled according to the leveling values ​​of the upstream stands of the finishing rolling; 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 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 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 roughing-finishing combined 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 roughing-finishing combined rolling according to claim 2, characterized in that: The formula of the leveling influence coefficient is as follows: 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 gain coefficient.

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

6.

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

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