Adjusting method for vertical roll load of each pass of hot rolling

Abstract

The invention relates to a method for adjusting the load of a vertical roll in each pass of hot rolling, which comprises the following steps of: S1, developing a load distribution correction value of each pass according to races, and calculating the load, S2, calculating the dog bone broadening deviation value of each pass, and S3, calculating the dog bone broadening deviation value by circularly calculating the dog bone broadening on the basis of S2. And the deviation between the target width of each pass and the actual width meets the precision requirement. Compared with traditional load calculation, the method has the advantages that the function of adjusting the load by using the dog bone broadening deviation of each pass is introduced, and the dog bone calculation of each pass is more accurate by calculating the deviation value of each pass of the same kind of strip steel. When the target width of each pass is set, the deviation between the set width and the actual width is more accurate, the purpose of load distribution optimization of each pass is achieved, and the width control is more accurate.

Description

Technical Field

[0001] This invention relates to a method, specifically a method for adjusting the load of vertical rolls in each pass of hot rolling, belonging to the field of hot continuous rolling roughing strip steel production control. Background Technology

[0002] The hot rolling roughing mill has four main stands, including R1 horizontal rolls and vertical rolls, and R2 horizontal rolls and vertical rolls. The goal of the roughing mill is to achieve the required strip width accuracy. Within the entire hot rolling production line, the width-controllable area lies in the two vertical roll sections of the roughing mill. The calculation and distribution of the vertical roll load is crucial for achieving the desired width. Factors affecting the vertical roll load distribution include the width reduction, the initial distribution coefficient for each pass, and the vertical roll reduction rate. This method optimizes the vertical roll load by adjusting both the initial distribution coefficient for each pass and the vertical roll reduction rate to improve width accuracy.

[0003] Chinese patent application CN201310005629.0 discloses an automatic load distribution method for roughing mill vertical rolls. The disclosed technical solution includes: (a) calculating the total natural width spread and effective width reduction of the roughing mill; (b) calculating the stability reduction limit of the vertical roll reduction pass based on the width-to-thickness ratio; (c) determining the distribution of vertical roll reduction using the stability reduction limit as a proportional factor; (d) calculating the effective reduction of each pass; (e) calculating the horizontal roll exit width of each forward pass as the width target for each forward pass; and (f) calling up the vertical roll reduction calculation of the stand, considering the dog-bone width spread, and recalculating the vertical roll reduction of each stand. In contrast, this technology achieves automatic load adjustment by calculating the dog-bone width spread deviation of the strip in each pass and using a bisection method.

[0004] Chinese patent application CN201910813287.2 discloses a dynamic correction method for roughing width based on vertical roll rolling force. The disclosed technical solution is characterized by: first, calculating the exit width deviation of the current pass using the original calculated rolling force; then, re-determining the entry width of the next pass; correcting the calculation error of the entry width of the next pass; and re-establishing the calculation point. The corrected exit width of the current pass is used as the entry width of the next pass, providing a more accurate benchmark value for subsequent pass load distribution calculations. In contrast, this technology compares the dog-bone width spread deviation of the strip in each pass and automatically adjusts the load on the next strip of the same type, thus achieving automatic load correction. The two technologies differ in that they do not.

[0005] The inventions mentioned above are all aimed at learning and width control of already rolled strip steel, and do not mention compensation and learning methods during the first rolling. Therefore, there is an urgent need for a new solution to this technical problem. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a method for adjusting the load of vertical rolls in each pass of hot rolling. The purpose of this technical solution is to provide a method for adjusting the load of vertical rolls in each pass of hot rolling so as to achieve automatic load adjustment when the width of the strip changes in each pass.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: a method for adjusting the load of vertical rolls in each pass of hot rolling, characterized in that the method includes the following steps:

[0008] S1. Develop load allocation correction values ​​for each circuit according to race, and calculate the load.

[0009] S2. Calculation of the deviation in dog bone width for each pass.

[0010] S3. Based on S2, calculate the dog bone width repeatedly until the deviation between the target width and the actual width in each pass meets the accuracy requirements.

[0011] Step S1 includes the following steps:

[0012] In the existing Meigang hot rolling control system, the load distribution principle of the roughing mill vertical rolls is based on the major strip classification, allocating the load coefficient for each pass. However, in actual rolling production, due to differences in customer requirements, strip characteristics, carbon equivalent, etc., the dogbone width properties will vary. Therefore, a load distribution optimization function for each pass needs to be developed. This includes the following steps:

[0013] S11, the configuration parameters are set according to the major categories of steel grades, as shown in the table below:

[0014]

[0015] The contents of the classification table are set. Currently, Meigang hot-rolled steel is divided into 16 categories based on carbon content, alloy content, and composition information. The total width interpolation value SpreadGain is first assigned to the default parameter 1.0.

[0016] S12, based on the pass number, interpolation allocation is performed for each pass. For the two reversible mills in the Meigang hot rolling roughing area, according to the line length, mill distribution, and product rolling specifications, the maximum number of rolling passes is ultimately determined to be 3+5. That is, mill R1 can roll a maximum of 3 passes, and mill R2 can roll a maximum of 5 passes. Since the vertical roll mill passes empty during reverse rolling, it can roll a maximum of 5 passes. The pass correction compensation table is as follows:

[0017]

[0018] S13, the final load correction for different races in the steel-carrying section is as follows:

[0019] gain = SpreadGain * PassGain; (Formula 1)

[0020] S14, Modify the calculation formula for the load of each pass:

[0021] W DOG [i] = f(thick, width, diam, inher)*gain (Formula 2)

[0022] Draft[i] = W ENTRY [i]-W EXIT [i]+W SPREAD [i]+dogrecov[i] (Formula 3)

[0023] in:

[0024] i: Rolling pass number;

[0025] dogrecov[i]: dogbread width of the vertical roller in the current pass;

[0026] f(thick, width, diameter, inherit): The formula for calculating the dog bone;

[0027] W ENTRY [i]: The entrance width of the current track;

[0028] W EXIT [i]: Exit width of the current track;

[0029] W SPREAD [i]: Horizontal width of the current lane;

[0030] Draft[i]: The vertical roll load for the current pass.

[0031] The calculation of the dog bone width deviation in each pass in step S2 is as follows:

[0032] Deviations will occur in each rolling pass of strip steel. Timely adjustment of the next strip steel of the same category for each deviation can effectively avoid the problem of low precision caused by cumulative deviations. The adjustment method is to correct the dog bone width. By improving the precision of the dog bone, the load distribution of each pass is more reasonable.

[0033] The specific steps are as follows:

[0034] S21, there is a width gauge at the exit of each of the roughing rolling zones R1 and R2. After the forward rolling is completed, the width deviation W of each pass is collected. dev Store in cache.

[0035] S22, determine the keywords for steel grade and product specifications, find the strip steel that needs correction according to the classification, and based on the general production characteristics of hot rolling, the keywords are steel tapping mark, width reduction classification, and incoming material width classification.

[0036] S23, Configure the adaptive table for each pass of the dog bone based on the keyword, the content of which is as follows:

[0037] Steel tapping mark Reduction amount classification Incoming material width Daocihao Adaptive value Dmod AP1360C1 1 1 1 1.0 AP1360C1 1 1 2 1.0 AP1360C1 1 1 3 1.0 AP1360C1 1 1 4 1.0

[0038] S24, Adaptive value adjustment method:

[0039] When the absolute value of the width deviation for each pass is |W dev When the width deviation is greater than 2.0mm, adaptive adjustment is initiated. The adjustment formula is as follows:

[0040] Dmod = 1.0 + W dev / dogrecov (Formula 4)

[0041] in:

[0042] Dmod: Adaptive value corresponding to each track classification

[0043] W dev Width deviation for each pass

[0044] dogrecov: The amount of dog bone recovery on the vertical roller for each pass.

[0045] S25, When calculating the same type of strip steel next time, the adaptive value will be substituted into the calculation of the dog bone width spread:

[0046] dogrecov=dogrecov*Dmod (Formula 5).

[0047] In step S3, the dog bone width is calculated iteratively until the deviation between the target width and the actual width in each pass meets the accuracy requirements, as detailed below:

[0048] S31, using the dog bone width calculated by Formula 5, calculate the target width for this round.

[0049] W EXIT =W ENTRY -draft+dogrecov+spread (Formula Six)

[0050] S32, compare the calculated target value of the number of passes with the actual value W of the same specification. act In comparison, when the deviation exceeds ±2mm, the adaptive value Dmod corresponding to each pass classification is adjusted, as shown in the table below:

[0051] <![CDATA[Deviation value (W act -W EXIT )]]> Adjustment amount delta 2mm 0.1 3mm 0.2 -2mm -0.1 -3mm -0.1

[0052] Dmod=Dmod+delta (Formula 7)

[0053] S32, substitute into the loop calculation until (W) act -W EXIT If the diameter is less than 2mm or the number of cycles exceeds 5,

[0054] S33 adjusts the target width of each pass by adjusting the dog-bone recovery amount accuracy. During load calculation, the target width of each pass is readjusted based on the dog-bone recovery amount. The dog-bone recovery amount adjustment method is as follows: collect the width deviation of each pass, calculate the slope based on the width deviation and the calculated dog-bone recovery amount, determine the width linear curve for each category, and adjust the dog-bone calculation offset. Furthermore, by collecting real-time production data from the field, this coefficient is continuously adjusted and updated to ensure that actual production and model calculations are updated synchronously and dynamically, reducing the occurrence of batch quality accidents. This method can achieve stable adjustment of the dog-bone recovery amount through automatic calculation, avoiding the instability of manual experience-based adjustments. Statistics from field production show that before dog-bone adjustment, strip steel with a width deviation exceeding 10% accounted for 20%. After applying this method, strip steel with a width deviation exceeding 10% accounted for less than 5%, and over 90% of strip steel had a width deviation within ±3. The improved dog-bone recovery amount accuracy ensured an 80% improvement in the load distribution accuracy of the roughing rolling area, achieving load optimization and improved accuracy.

[0055] Compared to existing technologies, this invention has the following advantages: Compared to traditional load calculation, this method introduces a function to adjust the load using the dog-bone width deviation of each pass. By calculating the deviation of each pass for strip of the same category, the dog-bone calculation for each pass is more accurate. When setting the target width for each pass, the deviation between the set width and the actual width is more precise, achieving the goal of optimizing the load distribution for each pass and making the width control more precise. Simultaneously, the linear curve of dog-bone recovery designed in this method is derived from extensive data analysis and can be dynamically adjusted in real time according to the on-site production conditions. This avoids the impact of load system errors caused by changes in equipment and environment during production on batch strip steel, saving costs and demonstrating high efficiency and innovation. It effectively avoids the problem of unstable load distribution caused by manual adjustments. Traditional technologies only adaptively adjust the final target width of roughing, failing to achieve local optimization of the load for each pass. The load distribution is unreasonable, and real-time adjustment is not possible, resulting in limited improvement in the final width accuracy. Detailed Implementation

[0056] To enhance understanding of the present invention, detailed descriptions are provided below in conjunction with embodiments.

[0057] Example 1: A method for adjusting the load of vertical rolls in each pass of hot rolling, characterized in that the method includes the following steps:

[0058] S1. Develop load allocation correction values ​​for each circuit according to race, and calculate the load.

[0059] S2. Calculation of the deviation in dog bone width for each pass.

[0060] S3. Based on S2, calculate the dog bone width repeatedly until the deviation between the target width and the actual width in each pass meets the accuracy requirements.

[0061] Step S1 includes the following steps:

[0062] In the existing Meigang hot rolling control system, the load distribution principle of the roughing mill vertical rolls is based on the major strip classification, allocating the load coefficient for each pass. However, in actual rolling production, due to differences in customer requirements, strip characteristics, carbon equivalent, etc., the dogbone width properties will vary. Therefore, a load distribution optimization function for each pass needs to be developed. This includes the following steps:

[0063] S11, the configuration parameters are set according to the major categories of steel grades, as shown in the table below:

[0064]

[0065] The contents of the classification table are set. Currently, Meigang hot-rolled steel is divided into 16 categories based on carbon content, alloy content, and composition information. The total width interpolation value SpreadGain is first assigned to the default parameter 1.0.

[0066] S12, based on the pass number, interpolation allocation is performed for each pass. For the two reversible mills in the Meigang hot rolling roughing area, according to the line length, mill distribution, and product rolling specifications, the maximum number of rolling passes is ultimately determined to be 3+5. That is, mill R1 can roll a maximum of 3 passes, and mill R2 can roll a maximum of 5 passes. Since the vertical roll mill passes empty during reverse rolling, it can roll a maximum of 5 passes. The pass correction compensation table is as follows:

[0067]

[0068]

[0069] S13, the final load correction for different races in the steel-carrying section is as follows:

[0070] gain = SpreadGain * PassGain; (Formula 1)

[0071] S14, Modify the calculation formula for the load of each pass:

[0072] W DOG [i] = f(thick, width, diam, inher)*gain (Formula 2)

[0073] Draft[i] = W ENTRY [i]-W EXIT [i]+W SPREAD [i]+dogrecov[i] (Formula 3)

[0074] in:

[0075] i: Rolling pass number;

[0076] dogrecov[i]: dogbread width of the vertical roller in the current pass;

[0077] f(thick, width, diameter, inherit): The formula for calculating the dog bone;

[0078] W ENTRY [i]: The entrance width of the current track;

[0079] W EXIT [i]: Exit width of the current track;

[0080] W SPREAD [i]: Horizontal width of the current lane;

[0081] Draft[i]: The vertical roll load for the current pass.

[0082] The calculation of the dog bone width deviation in each pass in step S2 is as follows:

[0083] Deviations will occur in each rolling pass of strip steel. Timely adjustment of the next strip steel of the same category for each deviation can effectively avoid the problem of low precision caused by cumulative deviations. The adjustment method is to correct the dog bone width. By improving the precision of the dog bone, the load distribution of each pass is more reasonable.

[0084] The specific steps are as follows:

[0085] S21, there is a width gauge at the exit of each of the roughing rolling zones R1 and R2. After the forward rolling is completed, the width deviation W of each pass is collected. dev Store in cache.

[0086] S22, determine the keywords for steel grade and product specifications, find the strip steel that needs correction according to the classification, and based on the general production characteristics of hot rolling, the keywords are steel tapping mark, width reduction classification, and incoming material width classification.

[0087] S23, Configure the adaptive table for each pass of the dog bone based on the keyword, the content of which is as follows:

[0088] Steel tapping mark Reduction amount classification Incoming material width Daocihao Adaptive value Dmod AP1360C1 1 1 1 1.0 AP1360C1 1 1 2 1.0 AP1360C1 1 1 3 1.0 AP1360C1 1 1 4 1.0

[0089] S24, Adaptive value adjustment method:

[0090] When the absolute value of the width deviation for each pass is |W dev When the width deviation is greater than 2.0mm, adaptive adjustment is initiated. The adjustment formula is as follows:

[0091] Dmod = 1.0 + W dev / dogrecov (Formula 4)

[0092] in:

[0093] Dmod: Adaptive value corresponding to each track classification

[0094] W dev Width deviation for each pass

[0095] dogrecov: The amount of dog bone recovery on the vertical roller for each pass.

[0096] S25, When calculating the same type of strip steel next time, the adaptive value will be substituted into the calculation of the dog bone width spread:

[0097] dogrecov=dogrecov*Dmod (Formula 5).

[0098] 4. The method for adjusting the load of vertical rolls in each pass of hot rolling according to claim 3, characterized in that the step...

[0099] In S3, the dog bone width is calculated iteratively until the deviation between the target width and the actual width in each pass meets the accuracy requirements, as detailed below:

[0100] S31, using the dog bone width calculated by Formula 5, calculate the target width for this round.

[0101] W EXIT =W ENTRY -draft+dogrecov+spread (Formula Six)

[0102] S32, compare the calculated target value of the number of passes with the actual value W of the same specification. act In comparison, when the deviation exceeds ±2mm, the adaptive value Dmod corresponding to each pass classification is adjusted, as shown in the table below:

[0103] <![CDATA[Deviation value (W act -W EXIT )]]> Adjustment amount delta 2mm 0.1 3mm 0.2 -2mm -0.1 -3mm -0.1

[0104] Dmod=Dmod+delta (Formula 7)

[0105] S32, substitute into the loop calculation until (W) act- W EXIT If the diameter is less than 2mm or the number of cycles exceeds 5,

[0106] S33, by adjusting the dog bone width accuracy, during load calculation, the target width of each pass is readjusted according to the dog bone width, thereby optimizing the load and improving accuracy.

[0107] Example 2:

[0108] Before this invention was developed, the width control of Meigang hot rolling mills had large deviations in each pass, as shown in the following example: 315594600300

[0109] Steel tapping mark: AQ0511K1

[0110] Steel grade classification: 7

[0111] Reduction amount classification: 7

[0112] Incoming material width: 3

[0113] Daocihao E11 (One) E13 (Second Road) E21 (Three-way) E23 (Four Roads) Width deviation -3.12 -3.57 3.2 4.5 Load Distribution 87.68 70.69 42.8 29.49

[0114] The load distribution was unreasonable because the last stage of the distribution was about to reach its limit (32), but the maximum load of the third stage (55) was not met.

[0115] The overall width is extra wide at 4.5mm.

[0116] After implementing this method, the rolling process is as follows:

[0117] The rolling process of 316056500800 strip steel.

[0118] Steel tapping mark: AQ0511K1

[0119] Steel grade classification: 7,

[0120] Reduction amount classification: 7,

[0121] Incoming material width: 3,

[0122] Major category compensation value,

[0123] Major Categories SpreadGain 7 1.01

[0124] Track compensation value

[0125] Daocihao Compensation value PassGain 1 1.01 2 1.02 3 1.03 4 1.04

[0126] Adaptive adjustment based on the dog bone passage number read after key reading.

[0127]

[0128]

[0129] Final control width and load

[0130] Daocihao E11 (One) E13 (Second Road) E21 (Three Roads) E23 (Four Roads) Width deviation 0.68 --0.99 -1.44 0.57 Load Distribution 81.18 51.86 33.44 18.12

[0131] The final overall width control deviation was 0.57, meeting the process control requirements, and the load distribution was reasonable and uniform.

[0132] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for adjusting the roll load of a hot rolling pass, characterized in that The method comprises the following steps: S1, developing each pass load distribution correction value according to the race, and calculating the load, S2, each pass dog bone width deviation amount calculation, S3, on the basis of S2, through the cycle calculation dog bone width, until each pass target width and actual width deviation meets the accuracy requirements.

2. The method of adjusting the stand roll load for hot rolling passes according to claim 1, characterized in that The step S1 comprises the following steps: S11, according to the large classification in steel grade, set configuration parameters, according to the large classification 1-16, give 1.0 SpreadGain confidence, Set the content in the classification table, currently, according to the carbon content, alloy content and composition information, etc., the hot rolling of Mei steel is divided into 16 races, and the total width expansion interpolation SpreadGain is set as the default parameter 1.0, S12, according to the pass number, each pass interpolation distribution is carried out, two reversible mills in the rough rolling area of Mei steel hot rolling, according to the rolling line length, the distribution of rolling mill and the rolling specification of product, the final determination of the maximum rolling pass number is 3+5, that is, the R1 mill is rolled for 3 passes at most, and the R2 mill is rolled for 5 passes at most, since the stand roll mill is empty when the reverse rolling is carried out, so the stand roll is rolled for 5 passes at most, and the pass correction compensation table is assigned with the initial compensation value PassGain as 1.0 according to the pass number S13, the load correction of different race strip passes is: Gain = SpreadGain * PassGain (Formula One) S14, the calculation formula of each pass load is modified: W DOG [i] = f(thick, width, diam, inher) * gain (Equation Two) Draft[i] = W ENTRY [i] - W EXIT [i] + W SPREAD [i] + dogrecov[i] (Equation Three) Wherein: I: the rolling pass number; Dogrecov[i]: the dog bone width of the current pass of the stand roll; F(thick, width, diam, inher): the calculation formula of the dog bone; W ENTRY [i] : entry width of the current pass; W EXIT [i] : exit width of the current pass; W SPREAD [i] : horizontal spread of the current pass; Draft[i]: the load of the current pass of the stand roll.

3. The method of adjusting the roll load of a hot rolling pass according to claim 2, characterized in that The step The calculation of each pass dog bone width deviation amount in S2 is as follows: S21, each of the rough rolling area R1, R2 has a width gauge, after the forward rolling is completed, the width deviation W of each pass is collected and stored in the buffer dev , S22, determine the steel grade and product specification key, find the strip steel that needs to be corrected according to the classification, according to the general production characteristics of hot rolling, the key is the tapping mark, the width reduction classification, the incoming material width classification, S23, configure the self dog bone each pass self adaptation table according to the key, the content includes the tapping mark, the width reduction classification, the incoming material width, the pass number, and determine the self adaptation value Dmod initial value 1.0 S24, self adaptation value adjustment method: When the absolute value of the width deviation |W dev |>2.0mm, start the width deviation to adapt to the adjustment, adjustment formula: Dmod = 1.0 + W dev dogrecov (Equation Four) Wherein: Dmod: the self adaptation value corresponding to each pass classification W dev : width deviation per pass Dogrecov: the corresponding stand roll dog bone recovery amount of each pass S25, when calculating the same type of strip steel next time, the self adaptation value is substituted into the calculation of the dog bone width: Dogrecov = dogrecov * Dmod (Formula Five).

4. The method of adjusting the roll load of a hot rolling pass according to claim 3, characterized in that The step In S3, the dog bone width is calculated through the cycle until the target width and the actual width deviation of each pass meets the accuracy requirements, which is as follows: S31, the target width of the current pass is calculated by using the dog bone recovery amount calculated by formula five, W EXIT = W ENTRY -draft + dogrecov + spread (Equation Six) S32, compare the calculated pass target value with the actual value W of the same specification act When the deviation exceeds 2mm, the adaptive value Dmod corresponding to each pass classification is adjusted, and the adjustment method is determined according to the deviation value. When the deviation value increases by 1mm, the adjustment amount increases by 0.

1. When the deviation value decreases by 1mm, the adjustment amount decreases by 0.

1. Dmod = Dmod + delta (Formula Seven) S32, substitute into the loop calculation until (W act -W EXIT )<2mm or the number of loops exceeds 5 times, S33, by adjusting the dog bone reply quantity precision, adjusting the target width of each pass, when calculating the load, according to the dog bone reply quantity, readjusting the target width of each pass, the dog bone reply quantity adjustment mode is: collecting the width deviation of each pass, according to the width deviation and the calculated dog bone reply quantity, calculating the slope, determining the width linear curve of each category, adjusting the dog bone calculation offset, and through collecting the real-time production data on site, continuously adjusting and updating this coefficient, ensuring that the actual production and model calculation can be updated synchronously, dynamically adjusting, reducing the batch quality accident.

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