Pickling rolling set tension compensation method

Abstract

The invention relates to an acid rolling set tension compensation method. The method comprises the following steps of (1) calculating set rolling force; (2) calculating a rolling force coefficient; (3) processing actual forward sliding; according to the technical scheme, an automatic compensation algorithm is designed, the tension set value is automatically compensated according to the actual rolling force and the actual forward slip in combination with factors such as rolling mill vibration and plate shape, manual intervention is reduced, and the acid rolling steel rolling automation rate is increased.

Description

Technical Field

[0001] The invention relates to a compensation method, in particular to a method for compensating a set tension of an acid rolling mill, and belongs to the field of automatic control of a cold rolling mill. Background Art

[0002] With the widespread application of full-automatic control technology, improving production automation rate, reducing manual intervention, and realizing full-automatic steel rolling are the general trend of the development of the steel rolling industry, and are also key technologies for product quality and labor efficiency. The tension setting of the cold rolling mill is a key control parameter for acid rolling production. In the actual production process of thin specifications, due to the influence of the rollers and emulsions, the deviation between the set tension and the actual rolling force is often large. The operator needs to intervene in the tension, and there is no unified standard for tension intervention. The extent of each person's intervention is different, which affects the production capacity of thin-gauge rolling and the thickness and plate shape control. In addition, as the number of rolling increases, the surface of the roller tends to be smooth. In the rolling process, the phenomenon of backward slippage, that is, negative forward slippage, often occurs, which is easy to cause the accident of broken strip and piled steel, seriously affecting the production of acid rolling. The set tension intervention rate is about 15%, and the manual operation intensity is high.

[0003] After searching, the patents related to this case are as follows: Patent application number is CN201210002077.3, the invention relates to a rolling process of high-strength cold-rolled strip steel, the high process realizes stable rolling of high-strength steel with large compression ratio by optimizing the setting of roller process parameters, rolling load distribution ratio coefficient, unit tension and unit additional tension of strip steel between stands, and rolling lubrication process parameters. Through this method, a pickling cold tandem rolling unit with a maximum rolling force of 2000 tons and a maximum motor load of 4500KW can be used to produce TRIP780 grade high-strength cold-rolled automotive strip steel with a compression ratio greater than 65%, and the product quality meets the requirements.

[0004] The tension setting value of the above patents is fixed, while the present invention is mainly to improve the stability of pickling thin material production, adopt the automatic compensation technology of setting tension, reduce manual intervention, and improve the automation rate of pickling. Summary of the invention

[0005] The present invention is aimed at the problems existing in the prior art, and provides a method for setting tension compensation for pickling rolling. The technical solution designs an automatic compensation algorithm, and automatically compensates for the tension setting value according to the actual rolling force and the actual forward slip, combined with factors such as mill vibration and plate shape, thereby reducing manual intervention and improving the automation rate of pickling steel rolling. In addition, it solves the problem that there is no unified standard for manual intervention, which affects the production capacity of thin-gauge rolling and the thickness and plate shape control, thereby improving the hourly output of pickling thin-gauge rolling, reducing the number of roll changes, and reducing the production cost of pickling rolling. In the pickling rolling production process, the actual rolling force and the actual forward slip are two main parameters reflecting the state of the rolling mill. By obtaining the actual rolling force and the actual forward slip value in the steady state of the rolling mill, the tension compensation coefficient is calculated according to the ratio of the actual rolling force to the set rolling force or according to the actual forward slip.

[0006] In order to achieve the above object, the technical scheme of the present invention is as follows: a method for setting tension compensation for pickling rolling; the method for setting tension compensation for pickling rolling comprises the following steps:

[0007] Step 1: Calculate the set rolling force,

[0008] Step 2: Calculate the rolling force coefficient,

[0009] Step 3: The actual forward slide process,

[0010] Step 4: Calculate tension compensation.

[0011] As an improvement of the present invention, step 1: calculating the set rolling force, specifically as follows: calculating the set rolling force of each stand according to data such as tension, deformation, deformation resistance of the material, roller radius, etc., the calculation steps are as follows: 1-1 calculating the average pressure reduction,

[0012] aveRed=1-0.25*hEntry÷H0-0.75*hExit÷H0

[0013] 1-2 Calculate the logarithmic elongation,

[0014] epsz=log(1.0÷(1.0-aveRed))

[0015] 1-3 Calculate static deformation resistance,

[0016] sksz=sl*exp(sn*log(epsz+sm))

[0017] 1-4 Calculate the relative deformation,

[0018] relRed=1.0-hExit÷hEntry1-5Calculate the extension rate of the rack strip steel,

[0019]

[0020] 1-6 Calculate the average deformation resistance,

[0021] skz=sksz*exp((5.0÷(sksz+23.0)-0.046)*log(1000.0*(ramdz)))

[0022] 1-7 Calculate the tension influence coefficient,

[0023] ftEffe=(1.0-uTenB÷skz)*(1.05+0.1*(1.0-uTenF÷skz)÷(1.0-uTenB÷skz)

[0024] -0.15*(1.0-uTenB÷skz)÷(1.0-uTenF÷skz))

[0025] 1-8 Calculation of rolling force PC

[0026]

[0027] temp2=1.0÷(skz*(tenEffe))-temp1*0.00214÷(hEntry-hExit)

[0028] temp3=1.08-1.02*relRedtemp4=temp1÷temp2+radius*0.00214÷2.0*(temp3÷temp2)*(temp3÷temp2)

[0029] temp5=(temp1÷temp2)*(temp1÷temp2)-radius*(hEntry-hExit)*(temp3÷temp2)*(temp3÷temp2)

[0030]

[0031] In the above calculation formula, hEntry is the entrance thickness of the frame, hExit is the exit thickness of the frame, H0 is the incoming material thickness, sl, sn, sm are three parameters of material deformation resistance, radius is the roller radius, vStrip is the strip speed, uTenB is the unit tension after the frame, and uTenF is the unit tension before the frame.

[0032] As an improvement of the present invention, step 2: calculating the rolling force coefficient is specifically as follows:

[0033] zp = pa / pc, where pa is the actual rolling force and pc is the calculated rolling force

[0034] When zp is greater than 15%, the front tension of the rack is increased by 10%;

[0035] When zp is less than 10%, the front tension of the rack is reduced by 10%.

[0036] As an improvement of the present invention, step 3: the processing of the actual forward slip is as follows: when the current slip is greater than -1%, the front tension of the rack is reduced by 20%; when the current slip is between -1% and 0%, the front tension of the rack is reduced by 10%.

[0037] As an improvement of the present invention, step 4: calculating tension compensation is as follows:

[0038] Set the output roll counter. Each time a roll is produced, the counter is incremented by 1 and cleared after the roll is changed. If the counter is equal to zero, it is the first roll after the roll is changed, and the tension of the first roll is not compensated.

[0039] Set the compensation flag, which will be cleared after the roll is changed. If the flag is zero and compensation is required, set the compensation flag to 1, otherwise no calculation is performed. This ensures that the compensation coefficient is calculated only once in a roll change cycle until the next roll change. The compensation coefficient reflects the current state of the rolling mill and has nothing to do with the type and specifications of the rolled product. Therefore, the compensation does not take into account the type and specifications of the previous and next strips.

[0040] During the calculation process, for each stand, first determine whether the forward slip needs to be compensated. If the forward slip has been compensated, the rolling force compensation of the stand will no longer be calculated, and the forward slip compensation will take priority.

[0041] Compared with the prior art, the present invention has the following advantages: during the pickling production process, this technical solution reduces manual intervention by setting automatic tension compensation, reduces operating labor intensity, improves tension setting accuracy and rolling stability, reduces the manual intervention rate of tension from 25% to less than 4%, increases the hourly output of thin-gauge steel from 92 tons / hour to 98 tons / hour, and reduces the number of roll replacement pairs of working rolls 4 and 5 frames from 205 pairs / month to 197 pairs / month, thereby achieving stable rolling of pickled thin-gauge strip steel and effectively reducing the production cost of pickled rolling. DETAILED DESCRIPTION

[0042] In order to deepen the understanding of the present invention, this embodiment is described in detail below.

[0043] Embodiment 1: A method for setting tension compensation for pickling rolling The method for setting tension compensation for pickling rolling comprises the following steps:

[0044] Step 1: Calculate the set rolling force,

[0045] Step 2: Calculate the rolling force coefficient,

[0046] Step 3: The actual forward slide process,

[0047] Step 4: Calculate tension compensation.

[0048] Among them, step 1: calculate the set rolling force, specifically as follows: calculate the set rolling force of each stand according to the tension, deformation, deformation resistance of the material, roller radius and other data, and the calculation steps are as follows: 1-1 calculate the average pressure,

[0049] aveRed=1-0.25*hEntry÷H0-0.75*hExit÷H0

[0050] 1-2 Calculate the logarithmic elongation,

[0051] epsz=log(1.0÷(1.0-aveRed))

[0052] 1-3 Calculate static deformation resistance,

[0053] sksz=sl*exp(sn*log(epsz+sm))

[0054] 1-4 Calculate the relative deformation,

[0055] relRed=1.0-hExit÷hEntry1-5Calculate the extension rate of the rack strip steel,

[0056]

[0057] 1-6 Calculate the average deformation resistance,

[0058] skz=sksz*exp((5.0÷(sksz+23.0)-0.046)*log(1000.0*(ramdz)))

[0059] 1-7 Calculate the tension influence coefficient,

[0060] ftEffe=(1.0-uTenB÷skz)*(1.05+0.1*(1.0-uTenF÷skz)÷(1.0-uTenB÷skz)

[0061] -0.15*(1.0-uTenB÷skz)÷(1.0-uTenF÷skz))

[0062] 1-8 Calculation of rolling force PC

[0063]

[0064] temp2=1.0÷(skz*(tenEffe))-temp1*0.00214÷(hEntry-hExit)

[0065] temp3=1.08-1.02*relRedtemp4=temp1÷temp2+radius*0.00214÷2.0*(temp3÷temp2)*(temp3÷temp2)

[0066] temp5=(temp1÷temp2)*(temp1÷temp2)-radius*(hEntry-hExit)*(temp3÷temp2)*(temp3÷temp2)

[0067]

[0068] In the above calculation formula, hEntry is the entrance thickness of the frame, hExit is the exit thickness of the frame, H0 is the incoming material thickness, sl, sn, sm are three parameters of material deformation resistance, radius is the roller radius, vStrip is the strip speed, uTenB is the unit tension after the frame, and uTenF is the unit tension before the frame.

[0069] Among them, step 2: calculating the rolling force rolling force coefficient is as follows:

[0070] zp = pa / pc, where pa is the actual rolling force and pc is the calculated rolling force

[0071] When zp is greater than 15%, the front tension of the rack is increased by 10%;

[0072] When zp is less than 10%, the front tension of the rack is reduced by 10%.

[0073] Among them, step 3: the processing of actual forward slip is as follows: when the current slip is greater than -1%, the front tension of the rack is reduced by 20%; when the current slip is between -1% and 0%, the front tension of the rack is reduced by 10%.

[0074] Among them, step 4: calculate tension compensation, as follows:

[0075] Set the output roll counter. Each time a roll is produced, the counter is incremented by 1 and cleared after the roll is changed. If the counter is equal to zero, it is the first roll after the roll is changed, and the tension of the first roll is not compensated.

[0076] Set the compensation flag, which will be cleared after the roll is changed. If the flag is zero and compensation is required, set the compensation flag to 1, otherwise no calculation is performed. This ensures that the compensation coefficient is calculated only once in a roll change cycle until the next roll change. The compensation coefficient reflects the current state of the rolling mill and has nothing to do with the type and specifications of the rolled product. Therefore, the compensation does not take into account the type and specifications of the previous and next strips.

[0077] During the calculation process, for each stand, first determine whether the forward slip needs to be compensated. If the forward slip has been compensated, the rolling force compensation of the stand will no longer be calculated, and the forward slip compensation will take priority.

[0078] Embodiment 2:

[0079] The present invention has been applied to the automatic control of the Meishan Iron and Steel 1420 five-stand six-roller UCM acid rolling mill, and can also be applied to other types of rolling mills.

[0080] Table 1 Equipment parameters of Meishan Steel 1420 acid rolling mill

[0081]

[0082] The first step is to calculate the rolling force

[0083] T4 material, steel mark DP1451K1, entrance thickness 2.0mm, width 836mm, exit thickness 0.18mm, the three parameters of deformation resistance of this steel type sl, sn, sm are 84, 0.32, 0.01. According to the second flow balance and the maximum exit speed of the rolling mill 1700mpm, the steel speed of the exit belt of each frame can be calculated. According to the load distribution ratio of each frame, the entrance and exit thickness of each frame can be calculated, and then the online roller diameter and tension table data can be obtained to calculate the rolling force of each frame.

[0084]

[0085] 1# rack 2# rack 3# rack 4# rack 5# rack Roller diameter 426 400.8 399.7 427.2 408.8 Average pressure 0.31279 0.60963 0.76362 0.84676 0.89862 Logarithmic elongation 0.37511 0.94066 1.44231 1.87574 2.28892 Static deformation resistance 61.8965 82.6509 94.6539 102.904 109.639 Relative deformation 41.7 43.9 36.6 34.4 33.6 Strip elongation rate 172.925 435.344 802.743 1418.43 2651.24 Average deformation resistance 72.3119 84.0858 94.6539 102.904 109.639 Tension influence coefficient 0.89006 0.85429 0.86133 0.86562 0.8861 Rolling force 888 755 703 636 580

[0086] Rolling force calculation process and results

[0087] The second step is to calculate the rolling force coefficient

[0088] Get the actual rolling force of 1-5 stands in steady state

[0089] 1# rack 2# rack 3# rack 4# rack 5# rack Set rolling force (pc) 888 755 703 636 580 Actual rolling force (pa) 905 801 713 751 680 Rolling force coefficient (zp) 1.02 1.06 1.01 1.18 1.19

[0090] Step 3: Actual forward sliding

[0091] Get the actual forward slide of racks 1-5 in steady state

[0092] 1# rack 2# rack 3# rack 4# rack 5# rack Actual forward slide 3.83 1.61 1.88 3.3 0.49

[0093] Step 4: Calculate tension compensation

[0094] According to the principle of giving priority to forward slip compensation, the actual forward slip is checked. Since the forward slip of frames 1-5 is greater than 0, no compensation is required based on the forward slip. Then the rolling force coefficient is checked. Since the rolling force coefficients of frames 4 and 5 are greater than 1.15, the forward tension of frames 4 and 5 needs to be compensated. The front tension is increased by 10% on the original basis. The results are shown in the following table.

[0095]

[0096] Embodiment 3:

[0097] The first step is to calculate the rolling force

[0098] CQ material, steel mark AQ0511K1, entrance thickness 2.5mm, width 1002mm, exit thickness 0.58mm, the three parameters of deformation resistance of this steel type sl, sn, sm are 73, 0.48, 0.01, according to the second flow balance and the maximum exit speed of the rolling mill 1293mpm, the steel speed of the exit belt of each frame can be calculated, according to the load distribution ratio of each frame, the entrance and exit thickness of each frame can be calculated, and then the online roller diameter and tension table data can be obtained to calculate the rolling force of each frame.

[0099]

[0100] 1# rack 2# rack 3# rack 4# rack 5# rack Roller diameter 435.0 411.6 400.0 420.5 410.7 Average pressure 0.21471 0.4483 0.59646 0.69402 0.75502 Logarithmic elongation 0.24171 0.59476 0.90748 1.18424 1.40659 Static deformation resistance 37.6489 57.3432 70.0438 79.4928 86.2819 Relative deformation 28.6 30.3 25.2 23.7 18.3 Strip elongation rate 187.601 339.871 489.473 695.574 840.204 Average deformation resistance 58.6027 70.5135 77.5171 82.5263 86.2819 Tension influence coefficient 0.89059 0.87058 0.87745 0.88336 0.89805 Rolling force 739 722 651 611 528

[0101] Rolling force calculation process and results

[0102] The second step is to calculate the rolling force coefficient

[0103] Get the actual rolling force of 1-5 stands in steady state

[0104] 1# rack 2# rack 3# rack 4# rack 5# rack Set rolling force (pc) 739 722 651 611 528 Actual rolling force (pa) 745 719 601 591 503 Rolling force coefficient (zp) 1.01 0.99 0.93 0.97 0.95

[0105] Step 3: Actual forward sliding

[0106] Get the actual forward slide of racks 1-5 in steady state

[0107] 1# rack 2# rack 3# rack 4# rack 5# rack Actual forward slide 2.43 1.51 1.68 1.24 -1.09

[0108] Step 4: Calculate tension compensation

[0109] According to the principle of giving priority to forward slip compensation, the actual forward slip is checked. Since the forward slip of 5 frames is less than 0, the forward tension of 5 frames needs to be compensated. According to the principle of giving priority to forward slip compensation, the rolling force coefficient of 5 frames is no longer checked, and the rolling force coefficient of 1-4 frames is checked. Since the rolling force coefficients of 1-4 frames are within the limit, there is no need to compensate for the tension of 1-4 frames. The results are shown in the following table.

[0110]

[0111] It should be noted that the above embodiments are not intended to limit the protection scope of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions all fall within the protection scope of the claims of the present invention.

Claims

1. A method for setting tension compensation for pickling rolling, characterized in that: The method comprises the following steps: Step 1: Calculate the set rolling force, Step 2: Calculate the rolling force coefficient, Step 3: The actual forward slide process, Step 4: Calculate tension compensation.

2. The method for setting tension compensation for pickling rolling according to claim 1, characterized in that: Step 1: Calculate the set rolling force, as follows: Calculate the set rolling force of each stand based on the tension, deformation, deformation resistance of the material, roller radius and other data. The calculation steps are as follows: 1-1 Calculate the average pressure, aveRed=1-0.25*hEntry÷H0-0.75*hExit÷H0 1-2 Calculate the logarithmic elongation, epsz=log(1.0÷(1.0-aveRed)) 1-3 Calculate static deformation resistance, sksz=sl*exp(sn*log(epsz+sm)) 1-4 Calculate the relative deformation, relRed=1.0-hExit÷hEntry 1-5 Calculate the extension rate of the rack strip steel. 1-6 Calculate the average deformation resistance, skz=sksz*exp((5.0÷(sksz+23.0)-0.046)*log(1000.0*(ramdz))) 1-7 Calculate the tension influence coefficient, ftEffe=(1.0-uTenB÷skz)*(1.05+0.1*(1.0-uTenF÷skz)÷(1.0-uTenB÷skz) -0.15*(1.0-uTenB÷skz)÷(1.0-uTenF÷skz)) 1-8 Calculation of rolling force PC temp2=1.0÷(skz*(tenEffe))-temp1*0.00214÷(hEntry-hExit) temp3=1.08-1.02*relRed temp4=temp1÷temp2+radius*0.00214÷2.0*(temp3÷temp2)*(temp3÷temp2) temp5=(temp1÷temp2)*(temp1÷temp2)-radius*(hEntry-hExit)*(temp3÷temp2)*(temp3÷temp2) In the above calculation formula, hEntry is the entrance thickness of the frame, hExit is the exit thickness of the frame, H0 is the incoming material thickness, sl, sn, sm are three parameters of material deformation resistance, radius is the roller radius, vStrip is the strip speed, uTenB is the unit tension after the frame, and uTenF is the unit tension before the frame.

3. The method for setting tension compensation for pickling rolling according to claim 1, characterized in that: Step 2: Calculate the rolling force. The rolling force coefficient is as follows: zp = pa / pc, where pa is the actual rolling force and pc is the calculated rolling force When zp is greater than 15%, the front tension of the rack is increased by 10%; When zp is less than 10%, the front tension of the rack is reduced by 10%.

4. The method for setting tension compensation for pickling rolling according to claim 1, characterized in that: Step 3: The actual forward slide process, The details are as follows: when the current slip is greater than -1%, the front tension of the rack is reduced by 20%; when the current slip is between -1% and 0%, the front tension of the rack is reduced by 10%.

5. The method for setting tension compensation for pickling rolling according to claim 2, characterized in that: Step 4: Calculate the tension compensation as follows: Set the output roll counter. Each time a roll is produced, the counter is incremented by 1 and cleared after the roll is changed. If the counter is equal to zero, it is the first roll after the roll is changed, and the tension of the first roll is not compensated. Set the compensation flag. After changing the roll, the flag is cleared. If the flag is zero and compensation is required, set the compensation flag to 1, otherwise it is not calculated. The compensation coefficient is calculated only once in a roll changing cycle until the next roll change. The compensation coefficient reflects the current state of the rolling mill and has nothing to do with the variety and specifications of the rolling. Therefore, the compensation does not consider the variety and specifications of the previous and next strips. During the calculation process, for each stand, first determine whether the forward slip needs to be compensated. If the forward slip has been compensated, the rolling force compensation of the stand will no longer be calculated, and the forward slip compensation will take priority.

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