L1 inclination value dynamic adjustment method for improving camber of rough rolling billet

Abstract

The invention discloses an L1 inclination value dynamic adjustment method for improving a rough rolling billet camber, which comprises the following steps of: detecting a width center line deviation value of a slab rolled by a rough rolling mill by a width gauge, uploading the width center line deviation value to an L2 system, calculating an inclination set value of the camber by the L2 system through a model, and issuing the inclination set value to an L1 system, and finally, executing an automatic camber control process by the L1 system. According to the invention, the L1 inclination value of the rough rolling billet camber is dynamically adjusted, so that the L1 full-automatic control of the rough rolling billet camber is realized, an operator is prevented from frequently operating a handle to correct the pressing inclination amount, and the phenomenon of large camber or frequent accidents can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to a rough rolling mill technology for hot rolling equipment, and more specifically to a method for dynamically adjusting the L1 inclination value of a rough rolling billet sickle bend. Background Art

[0002] The main reason for the sickle bending of the slab after rolling is the asymmetric deformation during rolling. The main factors causing asymmetric deformation include: temperature distribution in the width direction of the slab, rolling mill execution accuracy, thickness difference on both sides in the width direction of the slab, actual centering accuracy of the slab, etc. The sickle bending of the slab is the result of the combined effect of these factors.

[0003] The difficulty in controlling the camber of slabs lies mainly in the fact that there are many influencing factors, and some of these influencing factors are unmeasurable or difficult to measure accurately. For example: the temperature distribution on both sides of the slab width direction, the control accuracy of the rolling mill, the thickness on both sides of the slab, etc. Due to these uncertain factors, it is difficult to control the warping of the slab through theoretical modeling and obtain a good control effect.

[0004] At present, some patent documents propose to use the actual value of the rolling force on both sides of the roughing mill, the actual calculated value of the roll gap, and the bounce parameters on both sides of the stand as inputs. After calculation, the roll gap size on one side or both sides of the mill is adjusted to achieve the correction of sickle and wedge. There are also patent documents that propose to adjust the sickle of the slab by controlling the position of the side guide and the pressure of the side guide.

[0005] The current patents related to the button head include:

[0006] (1) The Chinese invention patent with the authorization announcement number CN 101934292B is a method for automatically controlling the camber and wedge of a hot strip roughing mill. It is mentioned that the actual value of the rolling force on both sides of the roughing mill, the actual calculated value of the roll gap, and the bounce parameters on both sides of the frame are taken as inputs. After accurate calculation, the camber and wedge correction is finally achieved by adjusting the roll gap size on one side or both sides of the mill. The control method of the present invention can achieve camber and wedge control without adding any camber shape detection device for the intermediate billet.

[0007] (2) The Chinese invention patent with the authorization announcement number CN 102441576B, "Automatic control method for camber and wedge of intermediate billet in hot-rolled steel strip rough rolling", discloses a novel automatic control method for camber and wedge of intermediate billet in hot-rolled steel strip rough rolling, which is applied to hot-rolled reversible rough rolling mills. The application discloses two technologies: one is the model control technology, and the other is the feedback control technology for the centerline offset of the intermediate billet. The model control is to take the actual value of the rolling force on both sides of the rough rolling mill, the actual calculated value of the roll gap, and the bounce parameters on both sides of the frame as input, and obtain the horizontal adjustment amount of the roll gap on one side or both sides of the rolling mill through precise calculation; the other is the feedback control technology for the centerline offset, which is to calculate the horizontal adjustment amount on both sides of the rolling mill after special processing of the centerline offset signal of the slab detected by the width gauge. The reasonable combination of these two technologies can well control the camber and wedge problems. The control method described in the invention avoids the need to add expensive and difficult to maintain intermediate billet wedge and camber detection devices.

[0008] (3) A Chinese invention patent with authorization announcement number CN 100566866C discloses a method for controlling the camber of a rough rolling intermediate slab. The technical solution adjusts the camber of the slab by controlling the position of the side guide plate and the pressure of the side guide plate.

[0009] (4) The Chinese invention patent with the authorization announcement number CN 103752623B is an automatic control method for improving the sickle bend of the rough rolling intermediate billet. The control method is divided into two parts: setting the roll gap tilt adjustment value of the current pass and correcting the roll gap tilt adjustment value of the exit sickle bend of the previous pass. The former can be calculated by the analytical model according to the set rolling force of the current pass, the set exit thickness, the roll gap setting value on both sides, the zero adjustment rolling force and the rolling mill stiffness value on both sides; the latter is calculated by the slab plastic deformation coefficient of the current pass and the measured rolling force and slab plastic deformation coefficient on both sides of the previous pass. The control method of the present invention uses the actual process parameters on site as input conditions, improves the automatic control model to effectively control the sickle bend of the intermediate billet, is convenient to operate, and can well improve the sickle bend problem of the intermediate billet.

[0010] (5) The Chinese invention patent with the authorization announcement number CN 104162549B is an automatic control method and system for the sickle camber of the intermediate billet of the hot rolling roughing mill. The technical solution obtains the center line offset of the intermediate billet according to the measurement of the slab width gauge; obtains the side length L1 of the first side and the side length L2 of the second side at the intermediate billet outlet according to the center line offset through the side length calculation formula; substitutes L1 and L2 into the conversion formula to obtain the first thickness deviation △h1 and the second thickness deviation △h2 on both sides of the intermediate billet outlet; substitutes △h1 and △h2 into the roll gap leveling value formula to obtain the roll gap leveling value △s; adjusts the roll gap value between the working rolls of the rolling mill according to the roll gap leveling value △s; so that the working rolls of the rolling mill can effectively control the sickle camber shape of the intermediate billet during the next pass of the intermediate billet.

[0011] (6) Chinese patent application No. 201910810128.7 discloses a camber control method based on analyzing the centerline deviation of the slab, which includes installing a camber measuring instrument before and after the reciprocating mill; using the camber measuring instrument to detect the centerline curve of the slab; judging the bending direction and degree according to the centerline deviation data curve; calculating the roll gap correction amount; correcting the roll gap correction amount according to the current pass width and the amount of reduction; L1 adjusts the roll gap difference on both sides of the horizontal roll according to the roll gap correction amount data, and the subsequent passes are rolled on this basis, thereby realizing automatic feedback control of the camber. It analyzes the centerline deviation data after the slab is rolled, and automatically calculates the roll gap difference setting value on both sides of the horizontal roll in the subsequent passes, thereby reducing the degree of camber bending, ensuring the straightness of the slab, reducing the labor intensity of the rough rolling operator, and improving the automation rate of rough rolling production.

[0012] The above-mentioned patents (1) and (2) calculate the adjustment amount of the single or double roll gap of the horizontal roll based on the actual values ​​of the rolling force on both sides of the horizontal roll, the roll gap, and the mill bounce. The disadvantage is that the mill stiffness is used in the mill bounce calculation, and the rough rolling usually adopts electric pressure reduction, and the stiffness test cannot be performed. Therefore, it is not realistic to obtain very accurate stiffness data, which leads to the calculated bounce data cannot be very accurate. Patent (3) controls the sickle bend by the side guide plates on both sides of the mill, which belongs to the adjustment of the sickle bend by mechanical equipment. The disadvantage of this method is that the risk of correcting the sickle bend by the side guide plates is very high, and it is easy to cause steel jamming. Patent (4) also calculates the sickle bend adjustment amount through a theoretical model based on rolling data. The disadvantage is the same as patents (1) and (2), that is, the stiffness calculation is inaccurate. Patent (5) calculates the length of the two sides of the slab, calculates the different extensions on both sides, and calculates the sickle bend adjustment amount through a model. This method is relatively complicated to calculate, and does not consider the influence of the slab pressure and slab width on the sickle bend control. Patent (6) solves the problem of the L2 automatic control of the roughing mill sickle control technology, but for L1, there is still only one manual method, that is, the operator manually adjusts the horizontal roll gap inclination value based on the roll gap correction amount automatically controlled by the rolling line L2, the plate shape visually monitored by the video, or the slab centerline deviation data fed back by the instrument side width meter, so as to achieve the purpose of adjusting the sickle at the mill exit.

[0013] At present, there are three heating furnaces in the 1580 production line in the steel plant. Each furnace type and the distance from the rolling line are different, resulting in different temperatures of the slabs drawn out of each furnace. After rough rolling, they present different sickle bends. For example, the slabs from the 1# furnace are bent in the working side direction, the 2# furnace is bent in the transmission side direction, and the 3# furnace may be bent in the working side direction. For this reason, the operator needs to frequently operate the handle to correct the amount of downward tilt, so as to control the amplitude of the sickle bend and ensure the finished coil shape. Since the 1580 production line has implemented the "1+N" operation station streamlining, a multi-post operator of N needs to take into account more operation points, and sometimes there is no time to adjust, resulting in frequent sickle bends or accidents.

[0014] Combination Figure 1 As shown, the current sickle control is mainly manual control, and the basic process is as follows:

[0015] S1. The width gauge detects the centerline deviation data of the slab and uploads it to the HMI screen of the L1 system (substrate automation system);

[0016] S2, the operator observes the actual value of the center line of the rolled slab and estimates the adjustment value of the next slab;

[0017] S3, the operator manually adjusts the tilt value through the operating handle;

[0018] S4. After adjustment, manually operate the APC button to set the roller gap on both sides;

[0019] S5. The roll gap setting value is executed and the rolling mill starts to feed steel.

[0020] However, there are still the following difficulties in realizing the automatic control of the sickle bend of the L1 system:

[0021] 1. When the on-site sickle bend is very large and exceeds the above threshold, it is not enough to control it by leveling the tilt value. Other factors such as slab temperature and roller diameter temperature should be considered and optimized at the same time to achieve better results;

[0022] 2. If the leveling tilt value is too large, it will make it difficult to control the convexity of the finished product in the subsequent finishing process, and there is a hidden danger of quality problems;

[0023] 3. When the width gauge fails, no centerline deviation data is uploaded to the L2 system (process calculation system);

[0024] 4. The side width meter is affected by external water vapor and the data is distorted or intermittent. Summary of the invention

[0025] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method for improving the dynamic adjustment of the L1 inclination value of the roughing billet sickle bend, by dynamically adjusting the L1 inclination value of the roughing billet sickle bend, fully automatic control of the roughing billet sickle bend L1 is achieved, avoiding the operator from frequently operating the handle to correct the downward inclination amount, and greatly reducing the frequent occurrence of large sickle bend phenomena or accidents.

[0026] To achieve the above object, the present invention adopts the following technical solution:

[0027] A method for improving the dynamic adjustment of the L1 tilt value of the rough rolling slab sickle camber:

[0028] The width centerline deviation value of the slab rolled out by the roughing mill is detected by a width gauge, and the width centerline deviation value is uploaded to the L2 system. The L2 system then calculates the inclination setting value of the sickle bend through a model and sends it to the L1 system. Finally, the L1 system executes the automatic control process of the sickle bend.

[0029] Preferably, the L1 system performs the automatic control process of sickle bending, which specifically includes the following steps:

[0030] S1, after receiving the tilt setting value, the L1 system determines whether the tilt setting value exceeds the threshold value. If so, it performs a steel swing action and alarms. If not, it enters step S2;

[0031] S2, preset the inclination setting value of the roll gap at the beginning of the current pass;

[0032] S3, determine whether the preset process of step S2 exceeds the set time, if so, alarm, if not, proceed to step S4;

[0033] S4, the electromagnetic clutch is closed and the roll gap tilt setting value is started to be executed;

[0034] S5. Start feeding steel and start rolling.

[0035] Preferably, in step S1, the L1 system determines whether the tilt setting value exceeds a threshold value by:

[0036] The L1 system calculates the maximum and minimum values ​​in real time according to the width centerline deviation value. When |maximum value-minimum value|>threshold value, the next steel feeding is stopped, an alarm is sounded and the semi-automatic adjustment mode is entered.

[0037] Preferably, the threshold is a program-fixed value of the L1 system, which is 3 mm.

[0038] Preferably, when the roll tilt setting value is abnormal, the L1 system issues an alarm and enters a semi-automatic adjustment mode.

[0039] Preferably, the time set in step S3 is 20 seconds.

[0040] The present invention provides a method for dynamically adjusting the L1 inclination value of the roughing billet sickle bend, which dynamically adjusts the L1 inclination value of the roughing billet sickle bend to achieve full automatic control of the roughing billet sickle bend L1, avoids the operator frequently operating the handle to correct the amount of downward inclination, and can greatly reduce the frequent occurrence of large sickle bends or accidents. In the existing method, the operator's manual control of the sickle bend is arbitrary, and the cognition and operating experience are inconsistent. For the centerline deviation curve of the same piece of steel, some operators believe that this amplitude does not require manual intervention, while some operators believe that intervention is required; after adopting the present invention, the adjustment rules are controlled by computer, and the sickle bend control has bid farewell to the original manual extensive control and has achieved automation and refined control, thus laying a good technical foundation for improving the plate shape at the outlet of the roughing mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the existing process of manually controlling the sickle bend;

[0042] Figure 2 It is a schematic diagram of the flow of the L1 tilt value dynamic adjustment method of the present invention;

[0043] Figure 3 It is a schematic diagram of the system architecture of the L1 tilt value dynamic adjustment method of the present invention. DETAILED DESCRIPTION

[0044] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] Combination Figure 2 and Figure 3 As shown, the present invention provides a method for dynamically adjusting the L1 inclination value of improving the sickle camber of the rough rolling billet:

[0046] The width gauge 1 (installed behind the roughing mill) detects the width centerline deviation value of the slab rolled out by the roughing mill, and uploads the width centerline deviation value to the L2 system 2 (process calculation system). The L2 system 2 then calculates the inclination setting value of the sickle bend through the model and sends it to the L1 system 3 (basic automation system). Finally, the L1 system 3 executes the sickle bend automatic control process.

[0047] In the HMI screen of L1 system 3, if AUTO mode is selected and then L2 ALL mode is selected, the automatic control process of sickle bend of L1 system 3 will be entered. If the operator needs to adjust the tilt amount semi-automatically, select L1 ALL mode and control it by inputting the correction tilt amount in the data box (semi-automatic control of sickle bend L1). If the operator needs to directly adjust the tilt amount manually, the mode will automatically switch from AUTO to MAN (full manual mode).

[0048] The automatic control process of the sickle bend performed by the L1 system 3 specifically includes the following steps:

[0049] After receiving the tilt setting value, the S1 and L1 systems 3 determine whether the tilt setting value exceeds the threshold value. If so, the steel swing action is performed and an alarm is sounded. If not, the process proceeds to step S2.

[0050] S2: The tilt setting value of the roll gap is preset at the beginning of the current pass, the electromagnetic clutch is turned on, the electromagnetic clutch between the high-speed pressing and the low-speed pressing on the transmission side is disengaged, the electromagnetic clutch between the high-speed pressing and the low-speed pressing on the working side is connected, and the working side pressing mechanism uses the low-speed pressing motor to execute the tilt setting value of the roll gap;

[0051] S3, determine whether the preset process of step S2 exceeds the set time, if so, alarm, if not, proceed to step S4;

[0052] S4, when the actual value of the roll gap inclination reaches the set value of the roll gap inclination, the electromagnetic clutch is closed, the starting clutches on both sides are opened, the low-speed pressing motor is disengaged, and the two high-speed pressing motors on both sides start to execute the set value of the roll gap inclination;

[0053] S5. After the roll gap is in place, start feeding steel and begin rolling.

[0054] Width gauge 1 continues to detect the slab centerline deviation data and uploads it to L2 system 2. L2 system 2 calculates the inclination value of the roll gap through the model, and then sends it to L1 system 3 as the inclination setting value of the sickle bend of the next piece of steel.

[0055] In step S1, the L1 system 3 determines whether the tilt setting value exceeds the threshold value as follows:

[0056] L1 system 3 calculates the maximum and minimum values ​​in real time according to the width centerline deviation value. When |maximum value - minimum value|>threshold value, it stops feeding the next pass, issues an alarm and enters semi-automatic adjustment mode.

[0057] The alarm mode is to display an alarm prompt on the HMI screen: R1 / 2Tilt Ref Overlimit (tilt setting value exceeds limit).

[0058] The necessity of setting an alarm for this process is: 1. When the sickle bend on site is very large and exceeds the above threshold, it is not enough to control it by leveling with the tilt value. Other factors such as slab temperature and roll diameter temperature should be considered and optimized at the same time to achieve better results. 2. If the leveling tilt value is too large, it will make it difficult to control the convexity of the finished product in the subsequent process of finishing rolling, and there is a hidden danger of quality problems.

[0059] The threshold is a fixed value of the L1 system 3 program, which is 3 mm.

[0060] When the inclination setting value of the rolling mill (R1 or R2) is abnormal (the width gauge 1 detects 999 mm), the L1 system 3 alarms and enters the semi-automatic adjustment mode, and the slab performs the steel swinging action until the setting value is not equal to 999 mm. The mode is allowed to switch back to the L1 full-automatic mode.

[0061] The alarm mode is to display the alarm prompt on the HMI screen: ALARM CODE 999.

[0062] The necessity of setting alarms in this process is: 1. When width gauge 1 fails, no centerline deviation data is uploaded to L2 system 2. 2. Width gauge 1 is affected by external water vapor and the data is distorted or intermittent. After these two problems occur, the automatic function of sickle bending cannot be realized, and the 999 alarm must be used to prompt the operator to notify the equipment maintenance personnel to eliminate the fault.

[0063] In step S3, the time is set to 20 seconds. When the L1 system 3 receives the newly issued set value, if the set action is not completed within 20 seconds, the steel swing action is performed and an alarm is issued. The alarm prompt is displayed on the HMI screen: R1 / 2Tilt ACTTIMEOUT.

[0064] The necessity of setting an alarm for this process is: after experiments, within the adjustment threshold, it can be completed fully automatically in 20 seconds. If it is not completed fully automatically, there must be a problem with the equipment, and the operator needs to notify the equipment personnel to check and deal with it.

[0065] When the sickle bend is manually controlled, the operator needs to adjust the inclination value of the roll gap about 20 times within 10 hours, while the L1 inclination value dynamic adjustment method of the present invention can adjust the inclination value of the entire roll gap as many as 225 times within 10 hours. It can be seen that before the present invention was adopted, the operator's manual control of the sickle bend was arbitrary, and the cognition and operating experience were inconsistent. For the centerline deviation curve of the same piece of steel, some operators thought that this amplitude did not require manual intervention, while others thought that intervention was required; some thought that an adjustment of 2 mm was required, while others thought that an adjustment of 4 mm was required. After the present invention was adopted, the adjustment rules were computer controlled. The number of inclination value adjustments of the automatic control of the sickle bend of the present invention is more than 10 times that of the original technology. The sickle bend control has bid farewell to the original manual extensive control and has realized automation and refined control, thus laying a good technical foundation for improving the plate shape at the outlet of the rough rolling mill.

[0066] The following table compares the monthly average values ​​of the maximum value of the centerline deviation of the width of the third pass of R2 before and after the implementation of the present invention:

[0067]

[0068]

[0069] It can be seen from the above table that after adopting the present invention, the maximum value of the centerline deviation of the width of the third pass of R2 outlet is significantly reduced, and the sickle bending plate shape control of R2 outlet is greatly improved, effectively preventing the large sickle bending phenomenon and accidents.

[0070] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for dynamically adjusting the L1 inclination value of a rough rolling slab sickle camber, characterized in that: The width centerline deviation value of the slab rolled out by the roughing mill is detected by a width gauge, and the width centerline deviation value is uploaded to the L2 system. The L2 system then calculates the inclination setting value of the sickle bend through a model and sends it to the L1 system. Finally, the L1 system executes the automatic control process of the sickle bend.

2. The method for dynamically adjusting the L1 inclination value of the rough rolling slab sickle camber according to claim 1 is characterized in that: The L1 system performs the automatic control process of sickle bending, which specifically includes the following steps: S1, after receiving the tilt setting value, the L1 system determines whether the tilt setting value exceeds the threshold value. If so, it performs a steel swing action and alarms. If not, it enters step S2; S2, preset the inclination setting value of the roll gap at the beginning of the current pass; S3, determine whether the preset process of step S2 exceeds the set time, if so, alarm, if not, proceed to step S4; S4, the electromagnetic clutch is closed and the roll gap tilt setting value is started to be executed; S5. Start feeding steel and start rolling.

3. The method for dynamically adjusting the L1 inclination value of the rough rolling slab sickle camber according to claim 2 is characterized in that: In step S1, the L1 system determines whether the tilt setting value exceeds the threshold value by: The L1 system calculates the maximum and minimum values ​​in real time according to the width centerline deviation value. When |maximum value-minimum value|>threshold value, the next steel feeding is stopped, an alarm is sounded and the semi-automatic adjustment mode is entered.

4. The method for dynamically adjusting the L1 inclination value of the rough rolling slab sickle camber according to claim 3 is characterized in that: The threshold is a program-fixed value of the L1 system, and is 3 mm.

5. The method for dynamically adjusting the L1 inclination value of the rough rolling slab sickle camber according to claim 2, characterized in that: When the roll tilt setting value is abnormal, the L1 system will give an alarm and enter a semi-automatic adjustment mode.

6. The method for dynamically adjusting the L1 inclination value of the rough rolling slab sickle camber according to claim 2, characterized in that: The time in step S3 is set to 20 seconds.

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