Automatic adjustment presetting control method for improving deviation of full-length center line of strip steel

Abstract

The invention discloses an automatic adjustment presetting control method for improving strip steel full-length center line deviation, which comprises the following steps that: a width gauge detects a width center line deviation value of a plate blank rolled by a roughing mill, and uploads the width center line deviation value to an L2 system, and the L2 system calculates a center line deviation correction value through a model; and working point position data of the AWC oil cylinders on the two sides are calculated according to the center line deviation correction value and issued to an L1 system so as to execute strip steel full-length center line deviation automatic adjustment preset control. According to the method, the quality problems of edge cracking, edge damage and the like of finished strip steel due to the fact that the head and the tail of the plate blank collide with a roller bed protection plate due to the phenomenon that the center line in the full-length direction of the plate blank deviates and overlaps a camber are solved.

Description

Technical Field

[0001] The invention relates to a roughing mill technology for hot rolling equipment, and more specifically to a method for improving automatic adjustment and presetting control of full-length center line deviation of a strip steel. 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 rolling 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 1As shown in the figure, when the 1580 production line adopts the fully automatic control mode of sickle bending L1, the above problems have been improved to a certain extent. The working principle of this mode is that after the slab is rolled by the rolling mill, the center line deviation curve of the slab is detected by the width gauge located behind the rolling mill, and the measured center line deviation curve data is transmitted to the L2 system (process control calculation system) through the network. The L2 system calculates the bending direction and degree of the current slab based on the characteristic data of the center line deviation curve of the current slab, and calculates the horizontal roller adjustment amount based on the bending direction and degree. The horizontal roller adjustment amount setting value is sent to the L1 system (automation basic system), and the L1 system adjusts it in place before feeding the steel according to the new roll gap tilt setting value for subsequent rolling.

[0015] However, when the stroke of the steel drawing machine in the previous process of the roughing mill is inaccurate, or the rolling center line of the mechanical structure of the width setting machine SP deviates, the strip rolled out by the roughing mills R1 and R2 will also deviate from the rolling center line as a whole. If it is serious and the sickle bend occurs at the head and tail of the strip, the edge of the strip is easy to rub against the roller guard plate, resulting in quality problems such as edge damage and edge cracking. Therefore, the existing sickle bend control method cannot solve this problem, and a control method for automatically adjusting the deviation of the center line of the entire length of the strip is needed. Summary of the invention

[0016] In view of the defects existing in the prior art, the purpose of the present invention is to provide a pre-set control method for improving the automatic adjustment of the center line deviation of the entire length of the strip, so as to avoid the head and tail of the slab hitting the roller guard plate due to the center line offset in the entire length direction of the slab and the sickle bend phenomenon, causing quality problems such as edge cracking and edge damage in the finished strip.

[0017] To achieve the above object, the present invention adopts the following technical solution:

[0018] A method for improving automatic adjustment of pre-set control of full-length centerline deviation of strip steel:

[0019] 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 centerline correction value through the model, and then calculates the working point position data of the AWC cylinders on both sides according to the centerline correction value, and sends it to the L1 system to execute the preset control of automatic adjustment of the centerline deviation of the entire length of the strip.

[0020] Preferably, the width centerline deviation value is the difference between the centerline of the roller and the centerline of the current rolled slab measured by the width gauge.

[0021] Preferably, the width centerline deviation value is between -30 and 30 mm.

[0022] Preferably, the working point position data of the AWC cylinders on both sides include a position setting value X1 of the working side AWC cylinder and a position setting value X2 of the transmission side AWC cylinder.

[0023] Preferably, the position setting value of the working side AWC cylinder X1=B-L1;

[0024] The position setting value of the transmission side AWC cylinder is X2=B+L1;

[0025] Wherein, B is the working point position of the AWC cylinder, ranging from 10 to 35 mm; L1 is the measured value of the width centerline deviation.

[0026] Preferably, the working point position B of the AWC cylinder is 25 mm.

[0027] The present invention provides a method for improving automatic adjustment of pre-set control of the full-length centerline deviation of steel strip. Based on the detected centerline deviation of the slab, the set value of the AWC cylinder position on both sides of the vertical rod is calculated while the roller gap value of the vertical rod remains unchanged. The full-length centerline position deviation of the slab is corrected and controlled by changing the static working point position of the AWC cylinder. Avoid the collision of the head and tail of the slab with the roller guard plate due to the centerline deviation of the full-length direction of the slab and the sickle bend phenomenon, which causes quality problems such as edge cracks and edge damage in the finished steel strip. The use of the pre-set control mode for automatic adjustment of the full-length centerline deviation of the steel strip has a very good inhibitory effect on the edge quality defects of various finished coils caused by the centerline deviation of the slab in the width direction caused by various factors, such as edge cracks and edge damage, thereby improving the success rate of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of the existing fully automatic control method of sickle bend;

[0029] Figure 2 It is a flow chart of a method for automatically adjusting and presetting a control method for improving the full-length centerline deviation of a strip steel according to the present invention;

[0030] Figure 3 Schematic diagram of the system architecture of the method for automatically adjusting the pre-set control of the full-length centerline deviation of the strip steel according to the present invention;

[0031] Figure 4 It is a schematic diagram of the width centerline deviation value;

[0032] Figure 5 It is a schematic diagram of the vertical rolls on the roughing mill;

[0033] Figure 6 It is a schematic diagram of the travel of various components on the roughing mill. DETAILED DESCRIPTION

[0034] 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.

[0035] Combination Figure 2 and Figure 3 As shown, the present invention provides a method for improving the automatic adjustment of the pre-set control of the center line deviation of the entire length of the strip:

[0036] 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. The L2 system 2 calculates the centerline correction value through the relevant setting model, and then calculates the working point position data of the AWC cylinders on both sides according to the centerline correction value, and sends it to the L1 system 3 to execute the preset control of automatic adjustment of the centerline deviation of the entire length of the strip.

[0037] After rolling, the actual width value and the actual width centerline deviation value of the rolled slab are generally measured. The width centerline deviation is generally the difference between the centerline of the roller and the centerline of the current rolled slab measured by the width gauge 1. During installation and commissioning, the width gauge 1 will use a ruler to adjust the centerline of the roller and the centerline of the width gauge 1 to be consistent as the zero point. Therefore, this indicator data can effectively reflect the size state of the slab in the width direction and the overall shape of the slab.

[0038] Combination Figure 4 As shown, line A is the center line of the roller, that is, the width gauge 1 is set as the basic zero line, line B is the center line of the slab, and the distance between the arrows is the width center line deviation value of the slab, which is equal to AB and is generally controlled between -30 and 30 mm.

[0039] Combination Figure 5 As shown, the rough rolling mill of the 1580 production line is equipped with an E1 vertical roller pressing system, which consists of a hydraulic pressing system 4 and an electric pressing system. The electric pressing system is controlled by two sets of variable frequency motors on the working side and the transmission side. Each set of variable frequency motors drives a vertical screw 5, which in turn drives two horizontal screws to realize electric width control.

[0040] The vertical roll width control is completed by electric pressing and hydraulic AWC. Electric pressing is used for fast and large stroke opening and closing of vertical rolls; while hydraulic AWC control is used for dynamic adjustment of vertical roll gap, which is realized by AWC hydraulic cylinder. When pre-swinging the roll gap, the electric and hydraulic actions are used together to set the roll gap.

[0041] When the AWC system is abnormal, it is automatically interlocked by the program or switched to quick opening by manual operation, and the AWC cylinder retracts to 0 position. At this time, the width setting is completely completed by electric pressure.

[0042] Combination Figure 5 and Figure 6As shown in the figure, the width of the slab rolled out by the rolling mill depends on the roll gap 6 of the vertical roll, and the roll gap 6 of the vertical roll depends on the mechanical screw stroke A, the AWC cylinder stroke position B and the roll diameter size C of the vertical roll. The mechanical screw stroke A is used for the static setting of the roll gap. Each piece of steel is automatically set by receiving the L2 system data before each steel feed. The roll diameter C of the vertical roll is a constant before the next roll change. The AWC cylinder stroke position B is used for dynamic control of the slab width. It is preset at the working point of 25mm before the slab is rolled, and various dynamic width controls such as SSC AWC are performed when the slab is rolled. The cylinder position floats around the working point of 25mm, and the range is approximately controlled between 10 and 35mm. Ideally, the center line of the rolled slab should coincide with the center line of the roller table, so that the slab can be transported in the middle of the roller table. However, in reality, the center line of the slab is not at the center line of the roller table due to the process of loading and drawing steel or SP rolling mill in the upstream process. If the deviation is serious, the impact of sickle bending will cause the roller table guard plate to be installed on the edge of the slab, causing production accidents or quality problems on the edge of the finished product. Moreover, if this problem occurs, the operator has no means to intervene and correct it during the rolling process.

[0043] The working point position data of the AWC cylinders on both sides include the position setting value X1 of the working side AWC cylinder and the position setting value X2 of the transmission side AWC cylinder. The position of the AWC cylinder can be preset before feeding the steel, so as to achieve the purpose of changing the working point position of the cylinder to adjust the deviation of the center line of the full length of the strip.

[0044] The position setting value of the AWC cylinder on the working side is X1=B-L1;

[0045] The position setting value of the AWC cylinder on the transmission side is X2=B+L1;

[0046] Wherein, B is the working point position of the AWC cylinder, ranging from 10 to 35 mm; L1 is the measured value of the width centerline deviation.

[0047] The working point position B of the AWC cylinder is 25mm.

[0048] In the present invention, the L2 system calculates and issues two vertical roll AWC cylinder position setting values ​​calculated based on the slab centerline deviation. The L1 system automatically controls the position setting of the four cylinders on both sides (working side and transmission side) of the AWC according to the received AWC cylinder position setting values ​​X1 and X2. Subsequent passes are rolled on this basis, thereby realizing automatic adjustment and preset control of the full-length centerline deviation of the strip.

[0049] Before the implementation of the present invention, the working point of the four AWC cylinders was 25 mm. After the deviation was corrected by 2 mm to the DS transmission side, the working point of the AWC cylinder on the OS working side was 27 mm, and the working point of the AWC cylinder on the DS transmission side was 23 mm.

[0050] After the implementation of the present invention, since it is detected that the center line of the slab deviates by 2mm toward the OS working side, the upper and lower AWC cylinders on the DS transmission side are set to 23mm, and the upper and lower AWC cylinders on the OS working side are set to 27mm, and the center position of the slab is corrected and rolled toward the transmission side.

[0051] After the implementation of the present invention, since it is detected that the center line of the slab deviates by 3mm toward the DS transmission side, the upper and lower AWC cylinders on the OS working side are set to 22mm, and the upper and lower AWC cylinders on the DS transmission side are set to 28mm, and the center position of the slab is corrected and rolled toward the working side.

[0052] 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 adjustment of the pre-set control of the center line deviation of the entire length of the strip, characterized by: 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 centerline correction value through the model, and then calculates the working point position data of the AWC cylinders on both sides according to the centerline correction value, and sends it to the L1 system to execute the preset control of automatic adjustment of the centerline deviation of the entire length of the strip.

2. The method for automatically adjusting and presetting the centerline deviation of the entire length of the strip according to claim 1 is characterized in that: The width centerline deviation value is the difference between the centerline of the roller and the centerline of the current rolled slab measured by the width gauge.

3. The method for automatically adjusting and presetting the control of the center line deviation of the entire length of the strip according to claim 2 is characterized in that: The width centerline deviation value is between -30 and 30 mm.

4. The method for automatically adjusting and presetting the centerline deviation of the entire length of the strip according to claim 2 is characterized in that: The working point position data of the AWC cylinders on both sides include a position setting value X1 of the working side AWC cylinder and a position setting value X2 of the transmission side AWC cylinder.

5. The method for automatically adjusting and presetting the control of the center line deviation of the entire length of the strip according to claim 4 is characterized in that: The position setting value of the working side AWC cylinder X1=B-L1; The position setting value of the transmission side AWC cylinder is X2=B+L1; Wherein, B is the working point position of the AWC cylinder, ranging from 10 to 35 mm; L1 is the measured value of the width centerline deviation.

6. The method for automatically adjusting and presetting the control of the center line deviation of the entire length of the strip according to claim 5 is characterized in that: The working point position B of the AWC cylinder is 25 mm.

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