A method for controlling the shape of a strip in a rolling mill

Abstract

The application relates to a plate shape control method for prolonging rolling kilometers of a rolling mill, which comprises the following steps: configuring a roll shape, configuring an asynchronous long-striding roll strategy, configuring a bending roll driving striding roll control model strategy, configuring a continuous same-width variable crown control model, and selecting corresponding strategies of a housing according to a finished product thickness. The plate shape control method for prolonging rolling kilometers of the rolling mill greatly improves the problem of serious local wear of a roll and improves the uniformity of roll wear. After the method is implemented, the roll consumption is greatly reduced, and the rolling kilometers of each set of rolls are improved. Meanwhile, batch rolling of small crowns is realized, and the waste rate of the strip steel is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to a plate shape control method for prolonging rolling kilometers of a rolling mill, and belongs to the technical field of metal smelting. BACKGROUND

[0002] Currently, the rolling kilometers of a set of work rolls of a general hot continuous rolling production line are generally 50-55 kilometers. With the promotion of extreme cost in the front line of the hot continuous rolling production, it is urgently needed to prolong the rolling kilometers of each set of work rolls to reduce the production cost. SUMMARY

[0003] The application aims to overcome the defects of the above-mentioned technology and provide a plate shape control method capable of effectively prolonging the rolling kilometers of a rolling mill.

[0004] To solve the above-mentioned technical problems, the technical scheme provided by the application is as follows: a plate shape control method for prolonging the rolling kilometers of a rolling mill, comprising the following steps:

[0005] (1) configuring the roll shape of a hot continuous rolling finishing mill; the hot continuous rolling finishing mill comprises F0, F1, F2, F3, F4, F5 and F6 racks arranged in sequence; wherein the F0 rack is a first rack, the F1, F2 and F3 racks are front end racks, the F4, F5 and F6 racks are rear end racks, and the F6 rack is a last rack;

[0006] the first rack of the finishing mill adopts a Parab flat roll, the front end racks of the finishing mill adopt a CVC roll shape, and in the rear end racks of the finishing mill, the F4 and F5 racks adopt Parab flat rolls, and the last rack adopts a CVC roll shape;

[0007] (2) configuring an asynchronous long roll shifting strategy; the F0 rack has no roll shifting, and the initial positions of the asynchronous long roll shifting of the F1 to F6 racks are 20%-50% of the forward positions of the roll shifting;

[0008] (3) configuring a roll bending driving roll shifting control model strategy; for the same width strip steel, the roll bending driving roll shifting control model is used to disturb the fixed roll shifting positions set in the model;

[0009] The control model controls the strip steel specifications according to the finished product thickness, and divides the strip steel into three grades according to the finished product thickness, which are: the first grade limit is: the finished product thickness is less than or equal to 1.82 mm, the second grade limit is: the finished product thickness is in the interval (1.82 mm, 2.5 mm], and the third grade limit is: the finished product thickness is greater than 2.5 mm;

[0010] For the control strategy of the roll bending driving roll shifting of the first grade, the driving roll shifting action change of ±3% is taken as the target, and the adjustment interval range of the roll bending is derived;

[0011] For the control strategy of the roll bending driving roll shifting of the second gear, the adjustment range of the roll bending is derived with the driving roll shifting action change of ±4.5% as the target;

[0012] For the control strategy of the roll bending driving roll shifting of the third gear, the adjustment range of the roll bending is derived with the driving roll shifting action change of ±11.5% as the target;

[0013] (4) A continuous same-width variable crown control model is configured; the specific steps are:

[0014] (4.1) In the plate shape model procedure table, the variable crown setting is configured according to the steel grade and the strip steel specification, and the variable crown setting is a group of numbers with 11 elements;

[0015] (4.2) The target crown of the strip steel is compensated for the continuous same-width strip steel; when the number of same-width strip steel blocks reaches the threshold value of the variable crown function, the counting starts, and the variable crown compensation value of the nth strip steel corresponds to the ith array element value in the array; at this time, i = n mod 11;

[0016] (4.3) Cycle in turn until the rolling plan is completed;

[0017] (5) For different specifications of small crown rolling control mode; when continuously rolling the same width, the front end stand of the finishing mill adopts the roll bending driving roll shifting model strategy; the rear end stand adopts the asynchronous long roll shifting strategy;

[0018] When continuously rolling the same width, the front end stand of the finishing mill adopts the roll bending driving roll shifting model strategy; the rear end stand adopts the asynchronous long roll shifting strategy, and the continuous same-width variable crown control model is also used.

[0019] When continuously rolling the same width, the front end stand of the finishing mill adopts the roll bending driving roll shifting model strategy; the rear end stand adopts the asynchronous long roll shifting strategy, and the continuous same-width variable crown control model is also used.

[0020] The further improvement of the above scheme is that: in step (3), for the control strategy of the roll bending driving roll shifting of the first gear, the adjustment range of the roll bending is between [-80KN, 80KN], and the change range of the roll bending driving roll shifting action is between [-3, 3].

[0021] The further improvement of the above scheme is that: in step (3), for the control strategy of the roll bending driving roll shifting of the second gear, the adjustment range of the roll bending is between [-120KN, 120KN], and the change range of the roll bending driving roll shifting action is between [-4.5, 4.5].

[0022] The further improvement of the scheme is that: in the step (3), for the control strategy of the roll bending drive roll shifting of the third gear, the adjustment range of the roll bending is between [-300KN, 300KN], and the change range of the roll bending drive roll shifting action is between [-11.5, 11.5].

[0023] The further improvement of the scheme is that: in the step (4.1), the variable convexity setting is recorded as Cvar[i]=[-0.004, -0.001, 0.002, 0.004, 0, 0.003, -0.002, 0.001, 0.003, 0, 0].

[0024] The further improvement of the scheme is that: in the step (2), after the initial position of the F6 stand of the finishing mill is configured, the adjustment is set according to whether the strip has a wave shape at the outlet of the finishing mill to ensure the stability of rolling.

[0025] The further improvement of the scheme is that: the asynchronous long strategy of the front-end stand follows that the forward step size is smaller than the negative step size; the asynchronous long strategy of the rear-end stand follows that the first forward step size is smaller than the negative step size, then the second forward step size is greater than the negative step size, and finally the forward and negative step sizes are synchronized; the forward and negative step sizes of the stand are limited by the hardware stroke of the roll shifting.

[0026] The plate shape control method for prolonging the rolling kilometers of the rolling mill greatly improves the problem of serious local wear of the roll and improves the uniformity of roll wear. After the method is implemented, the roll consumption is greatly reduced, and the rolling kilometers of each set of rolls are improved. At the same time, batch rolling of small convexity is also realized, and the waste of strip is reduced. DETAILED DESCRIPTION EMBODIMENT

[0027] The plate shape control method for prolonging the rolling kilometers of the rolling mill of the embodiment comprises the following steps:

[0028] (1) configuring the roll shape of the hot continuous rolling finishing mill;

[0029] The hot continuous rolling finishing mill comprises F0 stand, F1 stand, F2 stand, F3 stand, F4 stand, F5 stand and F6 stand arranged in sequence; wherein the F0 stand is the first stand, the F1 stand, the F2 stand and the F3 stand are the front-end stands, the F4 stand, the F5 stand and the F6 stand are the rear-end stands, and the F6 stand is the last stand;

[0030] The first stand of the finishing mill adopts a Parab flat roller, the front-end stand of the finishing mill adopts a CVC roller type, and in the rear-end stand of the finishing mill, the F4 stand and the F5 stand adopt a Parab flat roller, and the last stand adopts a CVC roller type; the CVC (Continuously Variable Crown, continuously variable crown roller type) roller type and the Parab flat roller roller type are coordinated; the first stand F0 stand of the finishing mill adopts a Parab flat roller, the front-end stands F1, F2 and F3 stands of the finishing mill adopt a CVC roller type, and in the rear-end stands F4, F5 and F6 stands of the finishing mill, the F4 stand and the F5 stand adopt a Parab flat roller, and the last stand F6 stand adopts a CVC roller type;

[0031] As shown in Table 1:

[0032] Table 1: Hot continuous rolling finishing mill roller type configuration

[0033]

[0034] (2) Configure an asynchronous long roll shifting strategy; the F0 stand has no roll shifting, and the initial positions of the asynchronous long roll shifting of the other F1 to F6 stands are 20%-50% of the forward roll shifting positions; the initial position of the last finishing mill stand, i.e., the F6 stand, is given according to the configuration, and in order to ensure rolling stability, it is necessary to comprehensively consider whether the strip at the finishing mill outlet has a wave shape to set and adjust.

[0035] The hot continuous rolling finishing mill front-end stand asynchronous long strategy follows: the forward step size is smaller than the negative step size. In order to ensure that the positive and negative roll shifting of the rear-end stand is alternated, the rear-end stand asynchronous long strategy follows: first, the forward step size is smaller than the negative step size; second, the forward step size is greater than the negative step size; and finally, the forward and negative step sizes are synchronized. The forward and negative step sizes of the finishing mill stand are limited by the hardware stroke of the roll shifting of the finishing mill stand. Taking the Meisteel 1422 hot continuous rolling production line as an example, the finishing mill stand asynchronous long roll shifting strategy configuration is shown in Table 2. The forward and negative step sizes of the finishing mill stand are limited by the hardware stroke of the roll shifting of the finishing mill stand.

[0036] Table 2: Hot continuous rolling production line asynchronous long roll shifting strategy configuration

[0037] initial position asynchronous long strategy F1 20 pos 2 neg 3 F2 40 pos 2 neg 3 F3 50 pos 2 neg 3 F4 50 pos 4 neg 5 F5 30 pos 4 neg 3 F6 50 pos 5 neg 5

[0038] (3) Configure a bending roller driven roll shifting control model strategy; for the same width strip, the bending roller driven roll shifting control model is used to disturb the fixed roll shifting position set by the model. The control model controls the strip specifications according to the finished product thickness, and the control ability of the hot continuous rolling production line equipment and the roll shifting control ability are comprehensively considered to define the control model. The adjustment range of the bending roller is related to the adjustable ability of the actual bending roller. The value range of the adjustment range of the bending roller for thick specifications is relatively large, and the value range of the adjustment range of the bending roller for thin specifications is relatively small.

[0039] The control model controls the strip steel specifications according to the finished product thickness, and divides the strip steel into three grades according to the finished product thickness, which are respectively: the first grade limit is: finished product thickness ≤1.82mm, the second grade limit is: finished product thickness in (1.82mm, 2.5mm] interval, and the third grade limit is: finished product thickness >2.5mm above;

[0040] For the control strategy of the bending roll driving roll shifting of the first grade, the adjustment interval range of the bending roll is derived with the target of driving roll shifting action change ±3%; the adjustment interval of the bending roll is between [-80KN, 80KN], and the change interval of the bending roll driving roll shifting action is between [-3, 3].

[0041] For the control strategy of the bending roll driving roll shifting of the second grade, the adjustment interval range of the bending roll is derived with the target of driving roll shifting action change ±4.5%; the adjustment interval of the bending roll is between [-120KN, 120KN], and the change interval of the bending roll driving roll shifting action is between [-4.5, 4.5].

[0042] For the control strategy of the bending roll driving roll shifting of the third grade, the adjustment interval range of the bending roll is derived with the target of driving roll shifting action change ±11.5%; the adjustment interval of the bending roll is between [-300KN, 300KN], and the change interval of the bending roll driving roll shifting action is between [-11.5, 11.5].

[0043] (4) Configure a continuous same-width variable crown control model; the specific steps are:

[0044] (4.1) In the plate shape model procedure table, configure the variable crown setting according to the steel grade and strip steel specification; the variable crown setting is a group of 11-element numbers; the variable crown setting is denoted as Cvar[i]=[-0.004, -0.001, 0.002, 0.004, 0, 0.003, -0.002, 0.001, 0.003, 0, 0];

[0045] (4.2) For continuous same-width strip steel, compensate the target crown of the strip steel; when the number of same-width strip steel blocks reaches the threshold value of using the variable crown function, start counting, and the variable crown compensation value of the nth strip steel corresponds to the i-th array element value in the array; at this time, i=n mod 11, that is, the remainder obtained by dividing the integer n by 11;

[0046] (4.3) Cycle in turn until the rolling plan is completed;

[0047] (5) For small crown rolling control mode of different specifications; when continuously rolling the same width, the front end stand of the finishing mill uses the bending roll driving roll shifting model strategy when the strip steel specification is the first grade and the second grade; the rear end stand uses the asynchronous long roll shifting strategy;

[0048] When continuously rolling with the same width, the strip steel specification is the third gear, the front end stand of the finishing mill adopts the bending roll driving and roll shifting model strategy, and the rear end stand adopts the asynchronous long roll shifting strategy, and the continuously same width variable crown control model is used.

[0049] When continuously rolling with the same width, the strip steel specification is the third gear, the front end stand of the finishing mill adopts the bending roll driving and roll shifting model strategy, and the rear end stand adopts the asynchronous long roll shifting strategy, and the continuously same width variable crown control model is used.

[0050] The front end stand asynchronous long strategy follows that the forward step size is smaller than the negative step size, the rear end stand asynchronous long strategy follows that the first forward step size is smaller than the negative step size, the second forward step size is greater than the negative step size, and the last forward and negative step sizes are synchronous, and the forward and negative step sizes of the stand are limited by the hardware stroke of the roll shifting.

[0051] The embodiment has the following characteristics:

[0052] (1) Through the mutual coordination of the CVC roll shape and the Parab flat roll shape in the finishing area, the small-diameter roll with a short service time is fully utilized.

[0053] (2) Through the implementation of the asynchronous long roll shifting strategy of the rear end stand, the cross section of the strip steel is effectively ensured.

[0054] (3) When continuously rolling with the same width, the bending roll driving roll shifting control model developed for the front end stand of the finishing mill controls the strip steel specification according to the thickness of the finished product in multiple gears. According to the strip steel specification and the different bending roll adjustment intervals, the change range of the driving roll shifting action is also different.

[0055] (4) When continuously rolling with the same width, the variable crown control model developed for the finishing area. The continuously multi-stage asynchronous long variable crown improves the uniform wear and prolongs more rolling kilometers.

[0056] (5) Different asynchronous long roll shifting strategy models, bending roll driving roll shifting control models and variable crown control models are used for different specifications, which are coordinated to realize uniform wear of the roll and prolong the rolling kilometers.

[0057] The present application is not limited to the above-mentioned embodiments, and any technical solution formed by equivalent replacement falls within the protection scope of the present application.

Claims

1. A method of strip shape control for extending the rolling kilometers of a rolling mill, characterized in that, The method comprises the following steps: (1) configuring the roll shape of a hot continuous rolling finishing mill; the hot continuous rolling finishing mill comprises F0 frame, F1 frame, F2 frame, F3 frame, F4 frame, F5 frame and F6 frame arranged in sequence; wherein the F0 frame is the first frame, the F1 frame, the F2 frame and the F3 frame are the front end frames; the F4 frame, the F5 frame and the F6 frame are the rear end frames; and the F6 frame is the last frame; the first frame of the finishing mill adopts Parab flat roll, the front end frames of the finishing mill adopt CVC roll shape, among the rear end frames of the finishing mill, the F4 frame and the F5 frame adopt Parab flat roll, and the last frame adopts CVC roll shape; (2) configuring an asynchronous long roll shifting strategy; the F0 frame has no roll shifting, and the initial positions of the asynchronous long roll shifting of the other F1 frame to F6 frame are 20%-50% of the forward position of the roll shifting; the asynchronous long strategy of the front end frame follows: the forward step is smaller than the negative step; the asynchronous long strategy of the rear end frame follows: the first forward step is smaller than the negative step; the second forward step is greater than the negative step; and the last forward step and the negative step are synchronous; the forward and negative steps of the frame are determined according to the roll shifting stroke of the hot continuous rolling production line, and the forward and negative steps of the frame are limited by the hardware stroke of the roll shifting of the frame; (3) configuring a bending roll driving roll shifting control model strategy; for the same width strip steel, the fixed roll shifting position set in the model is disturbed through the bending roll driving roll shifting control model; the control model controls the strip steel specifications according to the finished product thickness, and divides the strip steel into three grades according to the finished product thickness, which are: the first grade limit is: finished product thickness ≤1.82mm, the second grade limit is: finished product thickness is in the interval (1.82mm, 2.5mm], and the third grade limit is: finished product thickness >2.5mm; for the control strategy of the bending roll driving roll shifting of the first grade, the target is to change the driving roll shifting action by ±3%, and the adjustment interval range of the bending roll is derived; for the control strategy of the bending roll driving roll shifting of the second grade, the target is to change the driving roll shifting action by ±4.5%, and the adjustment interval range of the bending roll is derived; for the control strategy of the bending roll driving roll shifting of the third grade, the target is to change the driving roll shifting action by ±11.5%, and the adjustment interval range of the bending roll is derived; (4) configuring a continuous same width variable crown control model; the specific steps are: (4.1) in the plate shape model procedure table, the variable crown setting is configured according to the steel grade and the strip steel specification, and the variable crown setting is a group of numbers with 11 elements; (4.2) for the continuous same width strip steel, the target crown of the strip steel is compensated; when the number of the same width strip steel reaches the threshold value of the variable crown function, the count starts, the variable crown compensation value of the nth strip steel corresponds to the i th array element value in the array; at this time, i=n mod 11; (4.3) sequentially cycle until the rolling plan is completed; (5) for different specifications of small crown rolling control mode; when the continuous same width rolling is performed, and the strip steel specification is the first grade and the second grade, the front end frames of the finishing mill adopt the bending roll driving roll shifting model strategy; and the rear end frames adopt the asynchronous long roll shifting strategy. When continuously rolling with the same width, and the strip gauge is the third grade, the front end stand of the finishing mill adopts the model strategy of bending roll driving and roll shifting; the rear end stand adopts the asynchronous long roll shifting strategy, and the continuously same width variable crown control model is used; When continuously rolling with the same width, and the strip gauge is the third grade, the front end stand of the finishing mill adopts the model strategy of bending roll driving and roll shifting; the rear end stand adopts the asynchronous long roll shifting strategy, and the continuously same width variable crown control model is used; 2. The plate shape control method for extending the rolling mileage of a rolling mill according to claim 1, characterized by: When continuously rolling with the same width, and the strip gauge is the third grade, the front end stand of the finishing mill adopts the model strategy of bending roll driving and roll shifting; the rear end stand adopts the asynchronous long roll shifting strategy, and the continuously same width variable crown control model is used; 3. The plate shape control method for extending the rolling mileage of a rolling mill according to claim 1, characterized by: In the step (3), for the control strategy of the bending roll driving and roll shifting of the first grade, the adjustment interval of the bending roll is between [-80KN, 80KN], and the change interval of the bending roll driving and roll shifting action is between [-3, 3].

4. The plate shape control method for extending the rolling mileage of a rolling mill according to claim 1, characterized by: In the step (3), for the control strategy of the bending roll driving and roll shifting of the second grade, the adjustment interval of the bending roll is between [-120KN, 120KN], and the change interval of the bending roll driving and roll shifting action is between [-4.5, 4.5].

5. The plate shape control method for extending the rolling mileage of a rolling mill according to claim 1, characterized by: In the step (3), for the control strategy of the bending roll driving and roll shifting of the third grade, the adjustment interval of the bending roll is between [-300KN, 300KN], and the change interval of the bending roll driving and roll shifting action is between [-11.5, 11.5].

6. The plate shape control method for extending the rolling mileage of a rolling mill according to claim 1, characterized by: In the step (4.1), the variable crown setting is denoted as Cvar[i]=[-0.004, -0.001, 0.002, 0.004, 0, 0.003, -0.002, 0.001, 0.003, 0, 0]. In the step (2), the initial position of the F6 stand of the finishing mill is set according to the configuration, and then adjusted according to whether the strip has a wave shape at the outlet of the finishing mill to ensure the rolling stability.

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