A roughing vertical roll control method for improving plate width difference

Abstract

The application discloses a rough rolling vertical roll control method for improving the same plate width difference, which comprises the following steps of sampling rolling force and roll gap data for locking when biting steel in single stand rough rolling flat roll even pass, calculating head outlet thickness locking value, calculating real-time thickness difference, setting thickness difference threshold value of different even pass rolling mill outlet strip steel, judging when the real-time thickness difference exceeds the thickness difference threshold value, determining temperature low point starting position mark, carrying out register and extraction processing on the temperature low point starting position mark, and starting to compensate the vertical roll gap when the temperature low point starting position mark reaches the vertical roll compensation position. The method has the beneficial effects of making up the technical blank of the width deviation caused by the strip water beam printing position temperature low point, reducing the phenomenon that the width deviation caused by the length direction temperature low point position of the strip steel leads to the width inconsistency and the over tolerance, optimizing the drawbacks in the traditional control method, and having significant engineering application value and industry popularization significance.

Description

Technical Field

[0001] This invention relates to the field of metallurgical automation control technology, and in particular to a method for controlling roughing mill vertical rolls to improve the width difference of the same plate. Background Technology

[0002] In the field of hot strip rolling, strip width deviation is a relatively important quality indicator. When strip is reciprocated in the roughing zone of a single-stand reversible rolling mill, the control strategy of the vertical roll gap has a very important impact on the strip width.

[0003] In general control methods, short-stroke control of the vertical roll head and tail is used. Before the strip bites in, the vertical roll gap is reduced slightly based on the set body opening. After the head of the strip passes, the vertical roll gap returns to the set body gap at a certain slope. When the strip is about to be thrown out, the vertical roll gap will be further reduced based on the set body gap until the tail is thrown out. The purpose is to reduce the problem of excessive width at the head and tail of the strip during reversible rolling.

[0004] However, in actual production, it was found that during the heating process of the slab in the heating furnace, the water beam mark would cause the width to be too wide at the low temperature point along the length, which would lead to the phenomenon of width discrepancy and exceeding tolerance. Therefore, optimizing the vertical roller control strategy at the water beam mark position is of great significance for improving the width quality.

[0005] Currently, there is no existing technology that can improve the control method of roughing mill vertical rolls to address the problem of width exceeding limits caused by low temperature at the strip water beam mark position. This is especially true for algorithms involving strip thickness calculation, thickness difference exceeding limits, position tracking, and roll gap calculation and compensation. Therefore, we propose a roughing mill vertical roll control method to improve the width difference within the same strip. Summary of the Invention The purpose of this invention is to provide a method for controlling the width difference of roughing rolls in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions: A method for controlling the width difference of roughing mill vertical rolls includes the following steps: S1. During the alternating pass of the single-stand roughing mill, the sampled rolling force and roll gap data are locked, and the head exit thickness lock value is calculated. The formula for calculating the head exit thickness lock value is as follows: in, This is the locked value for the strip thickness at the exit of the even-pass roughing mill. This is the locking value for the head roll gap of the roughing even-pass rolling mill. This is the locking value for the rolling force at the head of the roughing even-pass. To adjust the rolling force to zero on the roughing mill, For the stiffness of the roughing mill; S2. Activate the automatic thickness control function of the roughing rolls to sample the exit thickness data of the strip during the rolling process and calculate the real-time thickness difference. The formula for calculating the real-time thickness difference is as follows: in, This refers to the real-time thickness difference of the strip at the exit of each roughing pass. This refers to the real-time thickness of the strip at the exit of the roughing mill's even-pass cycle. For the real-time roll gap of the roughing even-pass rolling mill, For the real-time rolling force of the roughing even-pass rolling; S3. Set the thickness difference threshold for strip steel exiting different even-pass rolling mills, determine when the real-time thickness difference exceeds the thickness difference threshold, and determine the starting position marker of the low temperature point. S4. Register and retrieve the starting position marker of the low temperature point to track when the low temperature point reaches the vertical roller. S5. When the starting position marker of the low temperature point reaches the vertical roll compensation point, begin compensating for the vertical roll gap. When the low temperature point marker leaves the vertical roll, cancel the vertical roll gap compensation. The vertical roll gap compensation formula is: in, This is the compensation amount for the gap between the vertical rolls of the roughing mill. For the real-time side pressure of the roughing mill vertical roll, This is the pressure lock value for the roughing mill vertical roll body. For the stiffness of the roughing mill vertical rolls, For the plastic stiffness of the rolled piece, This is the correction coefficient for the vertical roll gap compensation, with a value range of 0.1-1.5.

[0007] Furthermore, the thickness difference thresholds for the strip exiting different even-pass rolling mills mentioned in step S2 are given empirically. Specifically, the thickness difference threshold for the strip exiting the second pass of roughing mill is D2, with a value range of 0.15-0.25; the thickness difference threshold for the strip exiting the fourth pass of roughing mill is D4, with a value range of 0.1-0.2, all in mm; and the thickness difference threshold for the strip exiting the sixth pass of roughing mill is D6, which is given empirically and has a value range of 0.05-0.15, all in mm.

[0008] Further, in step S2, when the real-time thickness difference is greater than the set thickness difference threshold, a low temperature point position marker is generated, and the low temperature point start position marker is recorded as 1.

[0009] Furthermore, the specific method for registering and retrieving the starting position marker of the low temperature point in step S4 is as follows: Based on the distance between the horizontal and vertical rolls of the roughing mill and the strip speed at the exit of the horizontal roll mill, the strip head is tracked. When the strip head leaves the horizontal roll, the starting position marker of the current low temperature point is stored. When the strip head reaches the vertical roll, the stored markers are retrieved sequentially.

[0010] Furthermore, the compensation distance is the vertical roll compensation time of the starting position mark of the low temperature point multiplied by the strip speed, and the vertical roll compensation time of the starting position mark of the low temperature point is the lag response time when the vertical roll gap decreases to compensate for the low temperature point position when the starting position mark of the low temperature point reaches the vertical roll position.

[0011] Furthermore, the vertical roll compensation time for the starting position marker of the low temperature point in different passes is given empirically, as follows: The vertical roll compensation time for marking the starting position of the low temperature point in the second pass of roughing mill is T2, with a value range of 200-500, and the unit is ms. The vertical roll compensation time for the starting position marker of the low temperature point in the fourth pass of roughing mill is T4, with a value range of 500-800, and the unit is ms. The vertical roll compensation time for marking the starting position of the lowest temperature point in the 6th pass of the roughing mill is T6, with a value range of 800-1000, and the unit is ms.

[0012] The beneficial effects are as follows: The roughing mill vertical roll control method for improving the width difference of the same plate described in this invention fills the technical gap caused by the low temperature point at the water beam mark position of the strip steel by calculating and judging the strip steel thickness at the exit of the roughing mill horizontal roll, tracking the low temperature point mark, and calculating the vertical roll gap compensation amount. It reduces the phenomenon of width deviation caused by the low temperature point in the strip steel length direction. By calculating and judging thickness difference, tracking markers, and calculating compensation amount, the shortcomings of traditional control methods can be optimized. This provides a more reliable solution for controlling the excessive width of the water beam mark position in hot strip rolling, and has significant engineering application value and industry promotion significance. Attached Figure Description

[0013] Figure 1 This is an execution flowchart of a roughing mill vertical roll control method for improving the width difference of the same plate, as described in this invention. Detailed Implementation

[0014] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention provides a method for controlling the vertical roll of a roughing mill to improve the width difference within the same strip. The method includes sampling and locking rolling force and roll gap data during the even-pass roughing mill run on a single stand, and calculating the head exit thickness lock value; activating the automatic thickness control function of the roughing mill roll, sampling the exit thickness data of the strip during rolling, and calculating the real-time thickness difference; setting a thickness difference threshold for the exit strip of different even-pass mill runs, determining when the real-time thickness difference exceeds the threshold, and identifying a low-temperature point start position marker; storing and retrieving the low-temperature point start position marker to track when the low-temperature point reaches the vertical roll; starting roll gap compensation when the low-temperature point start position marker reaches the compensation distance from the vertical roll, and canceling roll gap compensation when the low-temperature point marker leaves the vertical roll.

[0016] The following combination Figure 1 The invention is further described, specifically including the following steps: S1. During the alternating passes of the single-stand roughing mill, the sampled rolling force and roll gap data are locked, and the head exit thickness lock value is calculated. The formula for calculating the head exit thickness lock value is as follows: in, This is the locked value for the strip thickness at the exit of the even-pass roughing mill. This is the locking value for the head roll gap of the roughing even-pass rolling mill. This is the locking value for the rolling force at the head of the roughing even-pass. To adjust the rolling force to zero on the roughing mill, For the stiffness of the roughing mill.

[0017] S2. Activate the automatic thickness control function of the roughing rolls to sample the exit thickness data of the strip during the rolling process and calculate the real-time thickness difference. The formula for calculating the real-time thickness difference is: in, For the real-time thickness difference of the strip at the exit of the even pass of the roughing mill, This refers to the real-time thickness of the strip at the exit of the roughing mill's even-pass cycle. This is the locked value for the strip thickness at the exit of the even-pass roughing mill. For the real-time roll gap of the roughing even-pass rolling mill, For the real-time rolling force of the roughing even-pass rolling, To adjust the rolling force to zero on the roughing mill, For the stiffness of the roughing mill.

[0018] S3. Set the thickness difference threshold for strip steel exiting different even-pass rolling mills, determine when the real-time thickness difference of the strip steel exceeds the thickness difference threshold, and define the starting position marker of the low temperature point. The threshold value for the strip thickness difference at the exit of the second pass of roughing mill is D2, which is empirically given and ranges from 0.15 to 0.25 mm. The threshold value for the strip thickness difference at the exit of the fourth pass of roughing mill is D4, which is empirically given and ranges from 0.1 to 0.2 mm. The threshold value for the strip thickness difference at the exit of the sixth pass of roughing mill is D6, which is empirically given and ranges from 0.05 to 0.15 mm. The real-time thickness difference... When the temperature difference exceeds the set thickness threshold, a low temperature point location marker is generated, with the low temperature point start location marker recorded as 1.

[0019] The compensation time for the vertical roll at the starting position of the low temperature point is set for different passes, as follows: The vertical roll compensation time for the starting position marker of the low temperature point in the second pass of roughing mill is T2. This value is given empirically and ranges from 200 to 500 ms. The vertical roll compensation time for the starting position marker of the low temperature point in the fourth pass of roughing mill is T4. This value is given empirically and ranges from 500 to 800 ms. The vertical roll compensation time for the starting position marker of the low temperature point in the 6th pass of the roughing mill is T6. This value is given empirically and ranges from 800 to 1000, with the unit being ms. The vertical roll compensation time for the starting position mark of the low temperature point is the lag response time when the vertical roll gap decreases to compensate for the low temperature point position when the starting position mark of the low temperature point reaches the vertical roll position. Therefore, the vertical roll compensation time for the starting position mark of the low temperature point is set.

[0020] S4. Register and retrieve the starting position marker of the low temperature point to track when the low temperature point reaches the vertical roller. The method for storing and retrieving the starting position marker of the low temperature point is as follows: Based on the distance between the horizontal and vertical rolls of the roughing mill and the strip speed at the exit of the horizontal roll mill, the strip head is tracked. When the strip head leaves the horizontal roll, the starting position marker of the current low temperature point is stored. When the strip head reaches the vertical roll, the stored markers are retrieved sequentially.

[0021] S5. When the starting position marker of the low temperature point reaches the vertical roll compensation point, compensation for the vertical roll gap begins. When the low temperature point marker leaves the vertical roll, the vertical roll gap compensation is canceled. The formula for vertical roll gap compensation is: The compensation distance is calculated by multiplying the vertical roll compensation time (marked by the starting position of the low temperature point) by the strip speed. This is the compensation amount for the gap between the vertical rolls of the roughing mill. For the real-time side pressure of the roughing mill vertical roll, This is the pressure lock value for the roughing mill vertical roll body. For the stiffness of the roughing mill vertical rolls, For the plastic stiffness of the rolled piece, This is the correction coefficient for the vertical roll gap compensation. This value is given empirically and ranges from 0.1 to 1.5.

[0022] The implementation process of the method of the present invention will be described below with reference to specific application examples.

[0023] In this application example, follow these steps: S1. When the steel bites during the alternating passes of the single-stand roughing mill, sample the rolling force and roll gap data and lock them to calculate the head exit thickness lock value. The formula for calculating the head outlet thickness lock value is as follows: Taking a single-stand roughing mill with two passes as an example, in a certain locking process, the locking value of the head roll gap is... The rolling force lock value at the head of the two roughing passes is 80mm. The rolling force of the roughing mill is 1500 tons with zero adjustment. The roughing mill stiffness is 1000 tons. The value is 500 ton / mm. The calculated value is the strip thickness lock value at the exit of the second roughing pass after this locking. It is 81mm.

[0024] S2. Activate the automatic thickness control function of the roughing rolls, sample the strip exit thickness data during the rolling process, and calculate the real-time thickness difference. The formula for calculating the real-time thickness difference is: In this application example, the data at the current moment is sampled, and the rolling force of the roughing even pass at the current moment is... The current roll gap is 1600 tons for the roughing mill's even-pass cycle. The roughing mill stiffness is 80.1 mm. The rolling force is 500 tons / mm, with zero adjustment on the roughing mill. The current thickness of the strip at the exit of the roughing mill's even-pass section is 1000 tons. The thickness of the strip at the exit of the even pass of the roughing mill is 81.3 mm. The thickness difference of the strip at the exit of the two roughing passes is calculated to be 81mm. It is 0.3mm.

[0025] S3. Set the thickness difference threshold for strip steel exiting different even-pass rolling mills, determine when the real-time thickness difference of the strip steel exceeds the thickness difference threshold, and define the starting position marker of the low temperature point.

[0026] In this application example, the threshold D2 for the strip thickness difference at the exit of the second pass of the roughing mill is set to 0.2 mm. The strip thickness difference at the sampling time is 0.3 mm, which is greater than 0.2 mm. Before this, there will be a moment when the strip thickness difference at the exit first reaches the thickness difference threshold, and then exceeds the threshold. This moment is the time when the second pass of the roughing mill generates the low temperature point starting position mark. After the thickness difference exceeds the limit after the second pass, the low temperature point position mark is generated. T2 is the vertical roll compensation time for the low temperature point starting position mark in this application example. Based on experience, it can be set to 200 ms, that is, 200 ms is the reaction time before the vertical roll performs compensation. The low temperature point starting position mark is recorded as 1.

[0027] S4. Register and retrieve the starting position marker of the low temperature point to track when the low temperature point reaches the vertical roller.

[0028] Specifically, the storage and retrieval of the starting position marker of the low temperature point includes: Based on the distance between the horizontal and vertical rolls of the roughing mill and the strip speed at the exit of the horizontal roll mill, the strip head is tracked. When the strip head leaves the horizontal roll, the starting position marker of the current low temperature point is stored. When the strip head reaches the vertical roll, the stored markers are retrieved sequentially.

[0029] S5. When the starting position marker of the low temperature point reaches the vertical roll compensation point, start compensating for the vertical roll gap. When the low temperature point marker leaves the vertical roll, cancel the vertical roll gap compensation.

[0030] The formula for compensating the gap between vertical rolls is as follows: In this application implementation, lateral pressure The pressure locking value of the roughing mill vertical roll body is 100 tons. The stiffness of the roughing mill vertical roll is 50 tons. The plastic stiffness of the rolled piece is 200 tons / mm. With a vertical roll gap compensation coefficient of 1 and a minimum thickness of 300 ton / mm, the vertical roll gap compensation amount for roughing mills can be calculated. It is 0.625mm; When the starting position marker of the low temperature point reaches the compensation distance from the vertical roll, compensation for the roll gap of the vertical roll begins. When the low temperature point marker at the sampling time reaches the vertical roll, the roll gap of the vertical roll is compensated by 0.625mm. Other marker points are calculated using the above formula.

[0031] Through the above application examples, it can be seen that the roughing mill vertical roll control method for improving the width difference of the same plate of the present invention can solve the problem of excessive width caused by the low temperature of the strip due to the low temperature at the water beam mark position in actual production by calculating the strip thickness at the exit of the roughing mill flat roll, tracking the low temperature mark, and calculating the vertical roll gap compensation amount.

[0032] This method for improving the control of vertical rolls in roughing mills to reduce the width difference of the same strip involves determining the low temperature point by calculating the strip thickness at the exit of the roughing mill's horizontal rolls, tracking the low temperature point markers, and calculating the roll gap compensation amount for the vertical rolls. The core logic is as follows: First, based on the thickness difference of the strip steel, the location of the low temperature point of the thicker strip is determined, thereby determining the location of the low temperature point of the water beam imprint. Then set the thickness difference exceeding the limit threshold and the temperature marker duration; Next, we will track the location of the lowest temperature point in the strip. Finally, calculate the vertical roll gap compensation.

[0033] This method for controlling the width difference of the vertical roll in roughing mill fills the technical gap caused by the low temperature point at the water beam mark position of the strip by calculating and judging the strip thickness at the exit of the roughing mill horizontal roll, tracking the low temperature point marker, and calculating the vertical roll gap compensation. Through thickness difference calculation, judgment, marker tracking, and compensation calculation, the shortcomings of traditional control methods can be optimized. It provides a more reliable solution for controlling the width of the strip at the water beam mark position in hot continuous rolling, and has significant engineering application value and industry promotion significance.

[0034] Compared with existing technologies, the above method has the following advantages: To determine the location of the low temperature point of the water beam mark, when the conventional single-stand roughing mill is reversibly rolling, the vertical roll is located in front of the horizontal roll of the roughing mill. During even-pass rolling, the strip first passes through the horizontal roll and then through the vertical roll. The location of the low temperature point where the thickness is too thick can be determined by calculating based on the thickness difference of the strip. Key parameters (such as the strip thickness difference thresholds D2, D4, and D6 at the exit of different even-pass rolling mills) are empirically given and adjustable. They can be optimized according to different steel grades, rolling processes, and equipment characteristics, which enhances the universality and scalability of the method. For example, the value range of D2 is 0.15-0.25mm, the value range of D4 is 0.1-0.2mm, and the value range of D6 is 0.05-0.15mm, which can be adapted to the judgment of excessive thickness difference in various situations. Key parameters (such as T2, T4, and T6) are given empirically and are adjustable. They can be optimized according to different steel grades, rolling processes, and equipment characteristics, which enhances the universality and scalability of the method. For example, the value range of T2 is 200-500ms, the value range of T4 is 500-800ms, and the value range of T6 is 800-1000mm, which can be adapted to various situations of thickness difference exceeding the limit. Position tracking can be performed, and the flat roll will generate a low temperature indicator. This indicator can be stored and retrieved to determine the timing for vertical roll start-up gap compensation. Key parameters (such as the vertical roll gap compensation correction coefficient kp) are empirically given and adjustable, and can be optimized according to different steel grades, rolling processes, and equipment characteristics, enhancing the universality and scalability of the method. For example, the value of kp ranges from 0.1 to 0.5, which can be adapted to various situations of vertical roll gap compensation.

[0035] Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for controlling the width difference of roughing mill vertical rolls, characterized in that, Includes the following steps: S1. During the alternating pass of the single-stand roughing mill, the sampled rolling force and roll gap data are locked, and the head exit thickness lock value is calculated. The formula for calculating the head exit thickness lock value is as follows: in, This is the locked value for the strip thickness at the exit of the even-pass roughing mill. This is the locking value for the head roll gap of the roughing even-pass rolling mill. This is the locking value for the rolling force at the head of the roughing even-pass. To adjust the rolling force to zero on the roughing mill, For the stiffness of the roughing mill; S2. Activate the automatic thickness control function of the roughing rolls to sample the exit thickness data of the strip during the rolling process and calculate the real-time thickness difference. The formula for calculating the real-time thickness difference is as follows: in, This refers to the real-time thickness difference of the strip at the exit of each roughing pass. This refers to the real-time thickness of the strip at the exit of the roughing mill's even-pass cycle. For the real-time roll gap of the roughing even-pass rolling mill, For the real-time rolling force of the roughing even-pass rolling; S3. Set the thickness difference threshold for strip steel exiting different even-pass rolling mills, determine when the real-time thickness difference exceeds the thickness difference threshold, and determine the starting position marker of the low temperature point. S4. Register and retrieve the starting position marker of the low temperature point to track when the low temperature point reaches the vertical roller. S5. When the starting position marker of the low temperature point reaches the vertical roll compensation point, begin compensating for the vertical roll gap. When the low temperature point marker leaves the vertical roll, cancel the vertical roll gap compensation. The vertical roll gap compensation formula is: in, This is the compensation amount for the gap between the vertical rolls of the roughing mill. For the real-time side pressure of the roughing mill vertical roll, This is the pressure lock value for the roughing mill vertical roll body. For the stiffness of the roughing mill vertical rolls, For the plastic stiffness of the rolled piece, This is the correction coefficient for the vertical roll gap compensation, with a value range of 0.1-1.

5.

2. The method for controlling the width difference of roughing mill vertical rolls according to claim 1, characterized in that: The thickness difference thresholds for the strip exiting different even-pass rolling mills mentioned in step S2 are given empirically. Specifically, the thickness difference threshold for the strip exiting the second pass of the roughing mill is D2, with a value range of 0.15-0.25; the thickness difference threshold for the strip exiting the fourth pass of the roughing mill is D4, with a value range of 0.1-0.2, all in mm; and the thickness difference threshold for the strip exiting the sixth pass of the roughing mill is D6, which is given empirically and has a value range of 0.05-0.15, all in mm.

3. The method for controlling the width difference of roughing mill vertical rolls according to claim 1, characterized in that: In step S2, when the real-time thickness difference is greater than the set thickness difference threshold, a low temperature point position marker is generated, and the low temperature point start position marker is recorded as 1.

4. The method for controlling the width difference of roughing mill vertical rolls according to claim 1, characterized in that: The specific method for registering and retrieving the starting position marker of the low temperature point in step S4 is as follows: Based on the distance between the horizontal and vertical rolls of the roughing mill and the strip speed at the exit of the horizontal roll mill, the strip head is tracked. When the strip head leaves the horizontal roll, the starting position marker of the current low temperature point is stored. When the strip head reaches the vertical roll, the stored markers are retrieved sequentially.

5. The method for controlling the width difference of roughing mill vertical rolls according to claim 1, characterized in that: The compensation distance is the vertical roll compensation time of the starting position mark of the low temperature point multiplied by the strip speed. The vertical roll compensation time of the starting position mark of the low temperature point is the lag response time when the vertical roll gap decreases to compensate for the low temperature point position when the starting position mark of the low temperature point reaches the vertical roll position.

6. The method for controlling the width difference of roughing mill vertical rolls according to claim 5, characterized in that: The vertical roll compensation time for the starting position marker of the low temperature point in different passes is given empirically, as follows: The vertical roll compensation time for marking the starting position of the low temperature point in the second pass of roughing mill is T2, with a value range of 200-500, and the unit is ms. The vertical roll compensation time for the starting position marker of the low temperature point in the fourth pass of roughing mill is T4, with a value range of 500-800, and the unit is ms. The vertical roll compensation time for marking the starting position of the lowest temperature point in the 6th pass of the roughing mill is T6, with a value range of 800-1000, and the unit is ms.

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