A method for automatically judging and controlling slippage during rough rolling process

Abstract

The present invention discloses a method for automatically judging and controlling slippage during a rough rolling process, which can realize monitoring coverage of the slippage phenomenon during the entire rolling process, including establishing a program for judging whether slippage occurs by setting the deviation between the rolling force and the actual rolling force, and an automatic control program after slippage. The slippage judgment model determines the slippage by comparing the proportional relationship between the collected actual rolling force data of the rough rolling mill and the set rolling force. When the specific conditions are met, the slippage judgment model determines that slippage occurs, and the slippage control program is started to control slippage, and the slippage control is realized by automatically reducing the rolling speed of the rough rolling mill. The present invention is a fully automatic control. Since the present invention judges whether slippage occurs by the relationship between the actual rolling force and the set rolling force, and controls slippage by reducing the rolling speed of the rough rolling mill after slippage occurs, the process will not cause adverse effects on production equipment, can effectively control slippage, ensure smooth production, reduce the cost caused by slippage, and improve economic benefits.

Description

Technical Field

[0001] The invention relates to the field of hot rolling and rough rolling control in the metallurgical field, in particular to a method for automatically judging and controlling slippage in a rough rolling process. Background Art

[0002] In the rough rolling area of ​​the hot rolling line in the metallurgical field, for example, the hot rolling rough rolling mill often slips between the slab and the working roll during the production and rolling process. The slipping during the rolling process will cause the slab to be unable to be rolled smoothly, resulting in poor plate shape, roll wear, and severe equipment vibration that damages the equipment. Severe slipping can cause steel jamming, resulting in production stoppage.

[0003] In the prior art, the slippage during rough rolling of steel is usually controlled by reducing the water used in the rolling process, reducing the amount of reduction in the slipping pass, reducing the rolling speed in the slipping pass, increasing the roughness of the rolls, and other measures. These measures are often manually intervened by operators, and the intervention process is affected by differences in people's reaction abilities, and the effectiveness of the intervention is not well guaranteed.

[0004] In addition, there are also automatic methods to achieve slip control. For example, the method disclosed in Chinese patent CN101745547B "Automatic control slip method suitable for rough rolling process" is to collect and calculate the average value of the actual rolling force in the front section after biting the steel as the rolling force benchmark. When the rolling force in the subsequent rolling process deviates greatly from the benchmark rolling force, it is considered that slippage has occurred. It is difficult to judge the phenomenon that the head starts to slip when biting the steel, and after the actual slip occurs, the conditions for triggering the slip control program are subject to many restrictions. There is a phenomenon that the model does not judge it as slippage after the actual slip. Summary of the invention

[0005] The object of the present invention is to provide a method for automatically judging and controlling slipping in a rough rolling process, which method can more effectively judge and control slipping through automatic control.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a method for automatically judging and controlling slippage during a rough rolling process, characterized in that it includes the following steps:

[0007] (1) Automatic judgment of slippage: collect the actual rolling force F of the working roll of the roughing mill and the set rolling force Fs of the corresponding pass; calculate the ratio of the actual rolling force F to the set rolling force Fs of the corresponding pass; if F / Fs>0.65, roll the steel normally at the current speed; if F / Fs≤0.65 and the duration T≥2.5 seconds, it is judged as a slippage phenomenon and execute step (2);

[0008] (2) Automatic control of slippage: When slippage occurs, the rolling process is automatically reduced in speed at a certain rate, and the actual rolling speed V1 and rolling force F1 after reduction in speed are compared with the set speed Vs and the set rolling force Fs of the corresponding pass, respectively. When V1>0.5Vs and F / Fs>0.65, the slippage is eliminated, the speed reduction is stopped, and the steel is rolled at the speed when the slippage is eliminated; if V1=0.5Vs and F / Fs≤0.65, the slippage is not eliminated, and the steel is rolled at a speed of 0.5Vs. If the steel cannot be rolled normally, an alarm signal is issued and manual processing is performed.

[0009] Preferably, during the rolling process, the rolling force data is collected every 0.05 seconds according to a collection cycle and compared with the set rolling force.

[0010] Preferably, in step (2), when the slip condition is met during the rolling process, the speed reduction function is automatically executed, and the speed is reduced from the current speed at a rate of 1.75 m / s².

[0011] The beneficial effect of the present invention is that the method of the present invention is used to fully automatically monitor and control the slippage phenomenon during the production rolling process. Specifically, the relationship between the actual rolling force and the set rolling force is used to determine whether the slippage occurs. After the slippage occurs, the rolling speed of the roughing mill is reduced to control the slippage. The process will not cause adverse effects on the production equipment, can effectively control the slippage, ensure smooth production, reduce the cost caused by the slippage, and improve economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art 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 paying creative work.

[0013] FIG. 1 is a schematic structural diagram of a rough rolling mill implementing an embodiment of the present invention.

[0014] FIG2 is a schematic flow chart of the method of the present invention.

[0015] FIG. 3 is a flowchart of the present invention applied to the R2 roughing mill.

[0016] FIG. 4 is a schematic diagram of actual data collection according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0018] The rough rolling mill used in the method of the present invention has a structure as follows:Figure 1 As shown, it includes an inlet roller table 1, an inlet transmission side guide plate 2, an inlet working side guide plate 3, a transmission side vertical roller 4, a working side vertical roller 5, a lower working roller main drive 6, an upper working roller main drive 7, a lower working roller 8, an upper working roller 9, an outlet transmission side guide plate 10, an outlet working side guide plate 11, and an outlet roller table 12. The slab 13 is placed on the roller table.

[0019] like Figure 2 , 3 As shown, the present invention provides a method for automatically determining and controlling slippage during a rough rolling process, comprising the following steps:

[0020] S1: Automatic judgment of slippage: Collect the actual rolling force F of the roughing mill working roll and the rolling force Fs set for the corresponding pass; calculate the ratio (F / Fs) of the actual rolling force F and the rolling force Fs set for the corresponding pass as K. If K>0.65, it is determined that there is no slippage, and the steel is rolled normally at the current speed. If K≤0.65, and the duration T≥2.5 seconds, it is determined to be a slippage phenomenon, and step S2 is executed.

[0021] S2: Automatic control of slippage: After the slippage occurs, the rolling is automatically reduced in speed at a certain rate, and the actual speed V1 and rolling force F1 after the reduction in speed are collected and compared with the set speed Vs and the set rolling force Fs of the corresponding pass respectively; the ratio of the rolling force F1 after the reduction in speed to the set rolling force Fs of the corresponding pass (F / Fs) is K1. When V1>0.5Vs and K1>0.65, it is determined that the slippage is eliminated, the speed reduction is stopped, and the steel is rolled at the speed when the slippage is eliminated. If V1=0.5Vs and K1≤0.65, the slippage is not eliminated, and the steel is rolled at the speed V1 (i.e. 0.5Vs). If the steel cannot be rolled normally, an alarm signal is issued and it is handled manually.

[0022] Preferably, during the rolling process, the rolling force and rolling speed data are collected every 0.05 seconds according to a collection cycle, and the rolling force data is compared with the set rolling force.

[0023] Preferably, in step S2, when the slip condition is met during the rolling process, the speed reduction function is automatically executed, and the speed is reduced from the current speed at a rate of 1.75m / s².

[0024] The following is an example of the application of the roughing mill in the 2250 hot rolling production line of Zhanjiang Steel.

[0025] Refer to Figure 4, which shows that during the working process, after the slab bites the steel, the ratio of the actual rolling force to the set rolling force is detected to be less than 0.65, and it lasts for more than 2.5s, and it is determined that slippage occurs; at time T1, the slip signal is triggered to reduce the rolling speed of the working roll, and the rolling mill starts the deceleration program and starts to decelerate at a rate of 1.75m / s². The rolling speed drops from about 3.7m / s to 3.0m / s. At time T2, the ratio of the actual rolling force to the set rolling force is restored to more than 0.65, the slippage is controlled, the slip signal disappears, and the slab continues to be rolled at the reduced rolling speed (3.0m / s).

[0026] Figure 4 The curves are:

[0027] Steel biting signal: R2 load relay on;

[0028] Slip signal: R2 ROLLING SLIP ALARM;

[0029] Set rolling force: R2 GAP FORCE SET XXXXX.X (kN);

[0030] Actual rolling force: R2 TOTAL ROLLING FORCE FBK(FILTER)[kN];

[0031] Upper working roll rolling speed feedback value: R2 TOP WR Speed ​​[m / s];

[0032] Lower working roll rolling speed feedback value: R2 BOT WR Speed ​​[m / s];

[0033] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The above content is only used to illustrate the technical solution of the present invention. Simple modifications or equivalent substitutions made by ordinary technicians in this field to the technical solution of the present invention do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for automatically determining and controlling slippage during a rough rolling process, characterized in that: The steps include: (1) Automatic judgment of slippage: collect the actual rolling force F of the working roll of the roughing mill and the set rolling force Fs of the corresponding pass; calculate the ratio of the actual rolling force F to the set rolling force Fs of the corresponding pass; if F / Fs>0.65, roll the steel normally at the current speed; if F / Fs≤0.65 and the duration T≥2.5 seconds, it is judged as a slippage phenomenon and execute step (2); (2) Automatic control of slippage: When slippage occurs, the rolling process is automatically reduced in speed at a certain rate, and the actual rolling speed V1 and rolling force F1 after reduction in speed are compared with the set speed Vs and the set rolling force Fs of the corresponding pass, respectively. When V1>0.5Vs and F / Fs>0.65, the slippage is eliminated, the speed reduction is stopped, and the steel is rolled at the speed when the slippage is eliminated; if V1=0.5Vs and F / Fs≤0.65, the slippage is not eliminated, and the steel is rolled at a speed of 0.5Vs. If the steel cannot be rolled normally, an alarm signal is issued and manual processing is performed.

2. The method for automatically determining and controlling slippage during rough rolling according to claim 1, characterized in that: During the rolling process, the rolling force data is collected every 0.05 seconds according to the collection cycle and compared with the set rolling force.

3. The method for automatically determining and controlling slippage during rough rolling according to claim 1, characterized in that: In the step (2), when the slip condition is met during the rolling process, the deceleration function is automatically executed, and the current speed starts to decelerate at a rate of 1.75m / s².

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