Automatic compensation dynamic control method for improving rough rolling billet camber

Abstract

The invention discloses an automatic compensation dynamic control method for improving the camber of a rough rolling billet, and the method comprises the steps: detecting the deviation value of a width center line of a slab rolled by a rough rolling mill through a width gauge, and uploading the deviation value of the width center line to an L2 system; the L2 system calculates a roll gap inclination set value through a model and issues the roll gap inclination set value to the L1 system so as to execute full-automatic static setting control of the camber; a temperature measuring instrument measures the temperature deviation value of the two sides of the plate blank, the temperature deviation value is uploaded to the L1 system, the L1 system calculates the roll gap inclination dynamic correction amount according to the thickness of the plate blank before rolling of each pass, the hardness group coefficient of the current plate blank issued by the L2 system and the roll gap inclination dynamic correction amount calculated by the L1 system through a model, and the roll gap inclination dynamic correction amount is calculated according to the thickness of the plate blank before rolling of each pass. The AGC system of the roughing mill is utilized to perform fully automatic dynamic control of the camber. According to the method, the inclination value is dynamically adjusted and controlled based on the temperature deviation of the two sides of the camber plate blank, the incoming material thickness and the hardness group coefficient, and the rough rolling blank camber inclination set value is compensated and corrected.

Description

Technical Field

[0001] The invention relates to a rough rolling mill technology for hot rolling equipment, and more specifically to an automatic compensation dynamic control method for improving the sickle bending of rough rolling billets. 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 in the figure, the existing fully automatic control method for sickle bending: the width gauge installed behind the roughing mill detects the width centerline deviation value of the rolled slab and uploads it to the L2 system (process calculation system). The L2 system sends the calculated ΔV' roll gap inclination correction value to the L1 basic automation control system through the network. The L1 control system adjusts the inclination value on both sides of the horizontal roll according to the received roll gap inclination correction value data, and the subsequent passes are rolled on this basis, thereby realizing feedback automatic control of the sickle bending of the slab. Summary of the invention

[0015] In view of the defects existing in the prior art, the purpose of the present invention is to provide an automatic compensation dynamic control method for improving the sickle bend of the rough rolling billet, based on the temperature deviation on both sides of the sickle bend slab, the thickness of the incoming material and the hardness group coefficient to dynamically adjust the inclination value, to achieve compensation correction of the L2 system set value of the sickle bend inclination of the rough rolling billet, and automatic dynamic control in the L1 system, to avoid the operator frequently operating the handle to correct the downward inclination amount, and greatly reduce the frequent occurrence of large sickle bend phenomena or accidents.

[0016] To achieve the above object, the present invention adopts the following technical solution:

[0017] A method for improving the automatic compensation dynamic control of rough rolling slab sickle camber:

[0018] The width gauge 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. The L2 system calculates the roll gap tilt setting value through the model and sends it to the L1 system to perform the fully automatic static setting control of the sickle bending;

[0019] The temperature meter measures the temperature deviation value on both sides of the slab and uploads the temperature deviation value to the L1 system. The L1 system calculates the dynamic correction amount of the roll gap inclination based on the slab thickness before each rolling pass, the hardness group coefficient of the current slab issued by the L2 system and the model of the L1 system, and uses the AGC system of the rough rolling mill to perform fully automatic dynamic control of the sickle bend.

[0020] Preferably, the roll gap tilt setting value △V′ is automatically set by the horizontal rolling mill and is executed by a motor-driven screw pressing system.

[0021] Preferably, two temperature measuring instruments are provided, corresponding to two side edges of the slab respectively.

[0022] Preferably, the dynamic correction amount of roll gap tilt △Q=△Q0+△Q1+△Q2;

[0023] Wherein, △Q0 is the adjustment amount of the temperature deviation value of the slab; △Q1 is the adjustment amount of the hardness group coefficient of the slab; △Q2 is the adjustment amount of the thickness of the slab.

[0024] Preferably, the temperature deviation value of the slab △t=△T1-△T0;

[0025] Where △T1 is the measured slab temperature; △T0 is the allowable deviation of temperature control.

[0026] Preferably, the tracking length of the slab is evenly divided into four length sections, and the temperature deviation value △t of the slab in each length section corresponds to a tilt dynamic adjustment value Q0.

[0027] Preferably, the hardness group coefficient of the slab is a constant and is divided into five grades, and the hardness group coefficient of the slab in each grade corresponds to a tilt dynamic adjustment value Q1.

[0028] Preferably, the thickness of the slab is an interval range value, which is divided into 5 grades, and the thickness of the slab in each grade corresponds to a tilt dynamic adjustment value Q2.

[0029] The present invention provides an automatic compensation dynamic control method for improving the sickle bend of the rough rolling billet. After adopting the automatic compensation dynamic control method for improving the sickle bend of the rough rolling billet, the edge quality defects of various finished coils caused by the large sickle bend caused by various factors, such as edge cracks and edge damage, are suppressed. The occurrence of large sickle bend accidents is prevented, and the success rate of products is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the existing fully automatic control method of sickle bend;

[0031] Figure 2 It is a flow chart of the automatic compensation dynamic control method of the present invention;

[0032] Figure 3 It is a schematic diagram of the system architecture of the automatic compensation dynamic control method of the present invention;

[0033] Figure 4 It is a schematic diagram of the relationship between temperature deviation and adjustment amount in the automatic compensation dynamic control method of the present invention;

[0034] Figure 5 It is a schematic diagram of the relationship between the hardness group coefficient and the adjustment amount in the automatic compensation dynamic control method of the present invention;

[0035] Figure 6 It is a schematic diagram of the relationship between slab thickness and adjustment amount in the automatic compensation dynamic control method of the present invention. DETAILED DESCRIPTION

[0036] 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.

[0037] Combination Figure 2 and Figure 3 As shown, the present invention provides an automatic compensation dynamic control method for improving the rough rolling billet sickle bending:

[0038] After the width gauge 1 (installed behind the roughing mill) detects the width centerline deviation value of the slab rolled out by the roughing mill, the width centerline deviation value is uploaded to the L2 system 2 (process calculation system). The L2 system 2 calculates the roll gap inclination setting value △V′ according to the relevant setting model and sends it to the L1 system 3 (basic automation system) to perform fully automatic static setting control of the sickle bend.

[0039] Thermometer 4 (two thermometers 4 are provided, installed in front of the rough rolling mill, corresponding to the two sides of the slab respectively) measures the temperature deviation value on both sides of the slab, and uploads the temperature deviation value to L1 system 3. L1 system 3 calculates the dynamic correction amount △Q of roll gap inclination according to the thickness of the slab before each rolling pass (measured by thickness gauge 5), the hardness group coefficient of the current slab sent by L2 system 2 and the setting model of L1 system 3, and performs fully automatic dynamic control of sickle bending through the AGC system of the rough rolling mill.

[0040] The roll gap tilt setting value △V′ sent by L2 system 2 to L1 system 3 is a preset value of the roll gap tilt setting of the roughing mill, that is, the adjustment value made by the roughing mill before steel is fed in. The roll gap tilt setting value △V′ is automatically set by the horizontal rolling mill and is executed by the motor-driven screw pressing system. This setting is completed before steel is fed in and rolled.

[0041] The dynamic correction value △Q of the roll gap inclination calculated by the L1 system 3 is the data calculated based on the factors affecting the sickle bend that are not taken into account in the prior art (such as the temperature difference on both sides of the slab, the slab thickness, and the slab material hardness group coefficient). During the slab rolling process, the AGC function of the rough rolling mill is used to adjust the inclination value on both sides of the horizontal roll, and subsequent passes are rolled on this basis, thereby achieving precise control of the slab sickle bend.

[0042] Dynamic correction amount of roll gap tilt △Q=△Q0+△Q1+△Q2;

[0043] Wherein, △Q0 is the adjustment amount of the temperature deviation value of the slab; △Q1 is the adjustment amount of the hardness group coefficient of the slab; △Q2 is the adjustment amount of the thickness of the slab.

[0044] The temperature deviation of the slab △t=△T1-△T0;

[0045] Where △T1 is the measured slab temperature; △T0 is the allowable deviation of temperature control.

[0046] The corresponding relationship between the dynamic correction value of roll gap tilt △Q0, the temperature deviation value △t of the slab and the slab tracking length △L is obtained by looking up the table, as shown in Table 1 and Figure 4As shown: By dividing the slab tracking length, it is evenly divided into 4 lengths. The average temperature deviation exceeding the standard value △t on both sides of the slab in these 4 lengths corresponds to a tilt dynamic adjustment value Q0. The data Q0 in this table is empirical data. If the adjustment amount is too large or too small during the model debugging process, manual adjustment is required.

[0047] Table 1 Relationship between the dynamic adjustment value of tilt and the temperature deviation value of the slab

[0048] Slab tracking length △L L1 L2 L3 L4 Temperature deviation exceeds the limit value △t △t1 △t2 △t3 △t4 Tilt dynamic adjustment value △Q0 Q01 Q02 Q03 Q04

[0049] The corresponding relationship between the hardness group coefficient Y of the slab and the tilt dynamic adjustment value Q1 is obtained by looking up the table, as shown in Table 2 and Figure 5 As shown: The hardness group coefficient of the slab is a constant Y, which is divided into 5 levels, usually ranging from Y1 to Y5. Each of the 5 hardness group coefficients corresponds to a tilt dynamic adjustment value Q1. The data Q1 in this table is empirical data. If the adjustment amount is too large or too small during the model debugging process, manual adjustment is required.

[0050] Table 2 Relationship between the dynamic adjustment value of tilt and the hardness group coefficient of the slab

[0051] Hardness group coefficient Y of slab Y1 Y2 Y3 Y4 Y5 Tilt dynamic adjustment value Q1 Q11 Q12 Q13 Q14 Q15

[0052] The corresponding relationship between the slab thickness coefficient H and the tilt dynamic adjustment value Q2 is obtained by looking up the table, as shown in Table 3 and Figure 6 As shown in the figure: the thickness H of the slab is a range value, which is divided into 5 thickness levels, usually ranging from Y1 to Y6. Each of the 5 slab thickness intervals corresponds to a tilt dynamic adjustment value Q2. The data Q2 in this table is empirical data. If the adjustment amount is too large or too small during the model debugging process, manual adjustment is required.

[0053] Table 3 Relationship between tilt dynamic adjustment value and slab thickness range

[0054] Slab thickness range H Y1-Y2 Y2-Y3 Y3-Y4 Y4-Y5 Y5-Y6 Tilt dynamic adjustment value Q2 Q21 Q22 Q23 Q24 Q25

[0055] 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 improving the automatic compensation dynamic control of rough rolling slab sickle camber, characterized in that: The width gauge 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. The L2 system calculates the roll gap tilt setting value through the model and sends it to the L1 system to perform the fully automatic static setting control of the sickle bending; The temperature meter measures the temperature deviation value on both sides of the slab and uploads the temperature deviation value to the L1 system. The L1 system calculates the dynamic correction amount of the roll gap inclination based on the slab thickness before each rolling pass, the hardness group coefficient of the current slab issued by the L2 system and the model of the L1 system, and uses the AGC system of the rough rolling mill to perform fully automatic dynamic control of the sickle bend.

2. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 1 is characterized in that: The roll gap tilt setting value △V′ is automatically set by the horizontal rolling mill and is executed by the motor driving the screw rod pressing system.

3. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 1 is characterized in that: The temperature measuring instruments are provided with two, corresponding to the two sides of the slab respectively.

4. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 1 is characterized in that: The dynamic correction amount of roll gap tilt △Q=△Q0+△Q1+△Q2; Wherein, △Q0 is the adjustment amount of the temperature deviation value of the slab; △Q1 is the adjustment amount of the hardness group coefficient of the slab; △Q2 is the adjustment amount of the thickness of the slab.

5. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 4 is characterized in that: The temperature deviation value of the slab △t=△T1-△T0; Where △T1 is the measured slab temperature; △T0 is the allowable deviation of temperature control.

6. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 5 is characterized in that: The tracking length of the slab is evenly divided into four sections, and the temperature deviation value △t of the slab in each section corresponds to a tilt dynamic adjustment value Q0.

7. The automatic compensation dynamic control method for improving the rough rolling slab sickle camber according to claim 5 is characterized in that: The hardness group coefficient of the slab is a constant and is divided into five grades. The hardness group coefficient of the slab in each grade corresponds to a tilt dynamic adjustment value Q1.

8. The automatic compensation dynamic control method for improving rough rolling slab sickle camber according to claim 5 is characterized by: The thickness of the slab is an interval range value, which is divided into 5 grades, and the thickness of the slab in each grade corresponds to a tilt dynamic adjustment value Q2.

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