A method for setting the tension of a hot continuous rolling coiling unit

Abstract

The present invention provides a method for setting the tension of a hot continuous rolling coiling unit. The method includes the following steps: establishing grades of steel strength and assigning a strength value to each strength level; constructing a basic formula for linearizing the tension according to the preset minimum strength, minimum width, and regression of the rolling thickness; determining the strength coefficient and the width coefficient; determining the total tension calculation formula based on the basic formula for linearizing the tension, the strength coefficient, and the width coefficient; and substituting the strength value corresponding to the strength level into the total tension calculation formula to determine the tension of the hot continuous rolling coiling unit. The tension of the present invention can be calculated linearly, avoiding the problems of tension setting jumps and the need for a large number of standard tables to be manually input in the traditional look-up table method. It also avoids the problems of width narrowing or end face misalignment caused by unreasonable tension settings when using the look-up table method.

Description

Technical Field

[0001] The present invention relates to the technical field of hot continuous rolling production, and specifically relates to a method for setting the tension of a hot continuous rolling coiling unit. Background Art

[0002] At present, during the hot continuous rolling production process, the coiling tension is one of the most important factors affecting the overall coil shape quality and production stability. The setting of the coiling tension is greatly affected by factors such as equipment capacity, steel grade, width, thickness, coiling temperature, etc. The conventional look-up table method requires a large amount of data to be entered based on factors such as width and thickness combined with practical experience, which is likely to cause problems such as unreasonable tension setting, no data for new cross-sections, and large differences in coil shapes for different steel grades, affecting the coil shape quality and even causing scrap steel.

[0003] In summary, the following problems exist in the prior art: how to reasonably set the tension of the hot continuous rolling coiling unit and improve the quality of the coil shape. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to reasonably set the tension of the hot continuous rolling coiling unit and improve the quality of the coil shape.

[0005] To achieve the above object, the present invention proposes a method for setting the tension of a hot continuous rolling coiling unit, and the method includes the following steps:

[0006] Establish a strength grading for steel grades, and assign a strength value to each strength grade of the steel grade;

[0007] According to the preset minimum strength and minimum width, construct a basic formula for linearizing the tension by regression according to the rolling thickness;

[0008] Determine the strength coefficient and the width coefficient;

[0009] According to the basic formula for linearizing the tension, the strength coefficient, and the width coefficient, determine the total tension calculation formula;

[0010] Substitute the strength value corresponding to the strength grade into the total tension calculation formula to determine the tension of the hot continuous rolling coiling unit.

[0011] Specifically, establishing the strength grading for steel grades includes: after the production line process is solidified, grading according to the actual sampled tensile strength of each steel grade and the strength at the actual coiling temperature of the steel grade, and assigning a strength value to each strength grade of the steel grade.

[0012] Specifically, the basic formula for linearizing the tension is:

[0013] Q1 = ah 2 + bh + c

[0014] In the formula: Q1 is the basic tension value; the unit is KN;

[0015] h is the thickness of the coiled strip; the unit is mm;

[0016] a is a constant, b is a constant, and c is a constant.

[0017] Specifically, the formula for determining the strength coefficient is:

[0018] q 系 = a1Q + b1

[0019] In the formula: q 系 is the strength coefficient;

[0020] Q is the strength of the steel grade; the unit is MPa;

[0021] Both a1 and b1 are constants obtained by back-calculating the actual tension according to the thinnest and thickest specifications of each steel grade under the condition of meeting the coil shape.

[0022] Specifically, the formula for determining the width coefficient is:

[0023] b 系 = a2B + b2

[0024] In the formula: b 系 is the width coefficient;

[0025] B is the width; the unit is mm;

[0026] Both a2 and b2 are constants obtained by back-calculating the actual tension according to the narrowest and widest specifications of the same steel grade under the condition of meeting the coil shape.

[0027] Specifically, the total tension calculation formula after introducing the strength factor and width factor is as follows:

[0028] Q 总 = (ah 2 + bh + c)*(a1Q + b1)*(a2B + b2).

[0029] Specifically, the basic tension Q1 introduces the build-up current during calculation, and the tension margin is relatively large, and it is linearly weakened when introducing the strength coefficient.

[0030] Specifically, the basic tension Q1 considers the build-up current during calculation, and the tension margin is relatively large, and it is linearly weakened when introducing the width coefficient.

[0031] Specifically, according to the fact that the unit tension decreases with the increase of thickness and the total tension increases with the increase of thickness, it is determined that the total tension has a quadratic correlation with the strip thickness, and the basic formula of tension linearization is regressed according to the lowest build-up current, the actual coil shape, the narrowing situation and the equipment design capacity.

[0032] Specifically, the tension range of the hot continuous rolling coiling unit is 30 - 85 KN, the thickness range is 1.2 - 12.77 mm, the width range is 800 - 1350 mm, and the highest coiling specification is 1350*4X70.

[0033] First step, classify all specifications according to the tensile strength.

[0034] Second step, determine the coefficients a, b, and c in the basic formula.

[0035] According to the lowest grade produced by the production line being Q195, that is, the tensile strength is 250 MPa, the minimum thickness is 1.2 mm, the minimum tension is 30 KN, and the minimum width is 800 mm, substituting into the basic formula, we get: 30 = a * 1.2 * 1.2 + b * 1.2 + c.

[0036] According to the maximum tension of 85 KN, the maximum thickness of 12.7 mm, the maximum width of 1350 mm, and the highest coiling specification of 1350*4X70 (width 1350 mm, thickness 4 mm, and the specification is X70 pipeline steel) designed for the production line; the actual tensile strength of Q195 is 250 MPa and the actual tensile strength of X70 is 600 MPa, calculate the tension of Q195 rolled with 12.7 * 800 mm as 85 * (12.7 / 4) * (800 / 1350) * (250 / 600) = 66.6 KN; substituting the tension value of Q195 into the basic tension formula, we can get: 66.6 = a * 12.7 * 12.7 + b * 12.7 + c.

[0037] According to the Q195 steel grade, the tension used for 800 * 1.2 mm is 30 KN, and the tension used for 800 * 12.7 mm is 66.6 KN. If the tension is linearly distributed, then the tension of Q195 rolled with 800 * 6.95 mm ((1.2 - 12.7) / 2 mm) is (66.6 + 30) / 2 = 48.3 KN. Since the tension formula is a parabola, the actual tension of Q195 rolled with 800 * 6.95 mm is greater than 48.3 KN. Select according to the coil shape quality during the actual production process of the production line, and determine the tension selection value as 58 KN. Substituting it into the basic tension formula, we can get:

[0038] 58 = a * 6.95 * 6.95 + b * 6.95 + c

[0039] The following three groups of formulas are obtained:

[0040] 30 = a * 1.2 * 1.2 + b * 1.2 + c,

[0041] 66.6 = a * 12.7 * 12.7 + b * 12.7 + c,

[0042] 58 = a * 6.95 * 6.95 + b * 6.95 + c

[0043] The three coefficients a, b, and c in the basic tension formula are calculated according to the above three formulas.

[0044] The beneficial effects of the present invention are as follows: The tension of the present invention can achieve linearized calculation, avoiding the problems of tension setting jumps and the need for manual input of a large number of standard tables in the traditional look-up table method. It also avoids the problems of width narrowing or end face misalignment caused by unreasonable tension settings when using the look-up table method.

[0045] The tension setting is more scientific and reasonable, and can achieve accurate calculation of tension under various coupling conditions of factors such as width, thickness, and steel type. It avoids the problems of large changes in coil shape or the need for manual substantial correction of tension setting values when using the original look-up table method that is divided into grades according to thickness and width. The coil shape control is more stable.

[0046] The present invention simplifies the tension setting and avoids the problem that when using the original look-up table method divided into grades according to thickness and width, the tension value cannot be read for new widths and new thicknesses. It completely solves the problems of no tension data due to incomplete thickness or width grading when using the look-up table method, which may lead to scrap steel and malfunctions. Description of the Drawings

[0047] Figure 1 It is a flowchart of a method for setting the tension of a hot continuous rolling coiling unit provided by an embodiment of the present invention. Detailed Embodiments

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] The principle of the present invention is as follows:

[0050] 1. Method for grading steel types and assigning strength values. According to the actual sampled tensile strength of each steel type and the strength in combination with the actual coiling temperature of the steel type, it is graded according to a certain strength level (30 or 50 MPa), and each strength level is assigned a strength value, and finally it is brought into the total tension calculation formula for tension calculation.

[0051] 2. Regression method of the basic tension formula. According to the fact that "the unit tension decreases with the increase of thickness, and the total tension increases with the increase of thickness", it is determined that the total tension has a quadratic correlation with the strip thickness, and the basic tension formula is regressed according to the minimum tension establishment current, the actual coil shape, the narrowing situation, and the equipment design capacity.

[0052] 3. Method for linearly weakening strength and width during total tension calculation. Since the base tension takes into account the tension - building current during calculation and has a large tension surplus, when introducing the influencing factors of strength and width, linear weakening is carried out according to the situation.

[0053] In the embodiment of the present invention, as Figure 1 , a method for setting the tension of a hot continuous rolling coiling unit is provided. The method includes the following steps:

[0054] Establish strength grading for steel grades, and assign a strength value to each strength level; after the production line process is solidified, according to the actual sampled tensile strength of each steel grade and the strength considering the actual coiling temperature of this steel grade, grading is carried out according to a certain strength level (30 or 50 MPa), and a strength value is assigned to each strength level. Finally, it is brought into the total tension calculation formula for tension calculation. For example: all products of a certain production line are graded according to a 50 - MPa gradient of tensile strength, and can be divided into 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 Mpa, etc. (set a 30 - or 50 - MPa gradient, which is basically consistent with the actual strength gradient of the product). If the measured tensile strength of Q355 is about 400 MPa, it can be put into the 400 - MPa grade, and the Q value in the total tension formula is directly brought in as 400 for calculation when calculating the total tension.

[0055] Construct a basic formula for tension linearization according to the preset minimum strength and minimum width by regression of rolling thickness; by comprehensively considering the minimum tension - building current of the coiler, the actual coiling shape, the narrowing situation, and based on the minimum coiling width and the lowest - strength steel grade designed by the equipment, the basic formula for tension linearization is obtained by regression according to the thickness.

[0056] Determine the strength coefficient and the width coefficient;

[0057] Determine the total tension calculation formula according to the basic formula for tension linearization, the strength coefficient, and the width coefficient;

[0058] Substitute the strength value corresponding to the strength level into the total tension calculation formula to determine the tension of the hot continuous rolling coiling unit.

[0059] Establishing strength grading for steel grades includes: after the production line process is solidified, grading is carried out according to the actual sampled tensile strength of each steel grade and the strength of this steel grade at the actual coiling temperature, and a strength value is assigned to each strength level.

[0060] The basic formula for tension linearization is:

[0061] Q1 = ah 2 + bh + c

[0062] In the formula: Q1 is the basic tension value;

[0063] h is the thickness of the coiled strip steel;

[0064] a is a constant, b is a constant, c is a constant, and these three constants are obtained, for example, by using the above formula and performing a quadratic regression calculation of the actual set tension according to the most representative steel grade(s) of the production line.

[0065] The formula for determining the strength coefficient is:

[0066] q 系 = a1Q + b1

[0067] In the formula: q 系 is the strength coefficient;

[0068] Q is the steel grade strength;

[0069] Both a1 and b1 are constants obtained by back-calculating the actual tension according to the thinnest and thickest specifications of each steel grade under the condition of meeting the coil shape.

[0070] The formula for determining the width coefficient is:

[0071] b 系 = a2B + b2

[0072] In the formula: b 系 is the width coefficient;

[0073] B is the width;

[0074] Both a2 and b2 are constants obtained by back-calculating the actual tension according to the narrowest and widest specifications of the same steel grade under the condition of meeting the coil shape.

[0075] The total tension calculation formula after introducing the strength factor and width factor is as follows:

[0076] Q 总 = (ah 2 + bh + c) * (a1Q + b1) * (a2B + b2).

[0077] When calculating the basic tension Q1, the build-up current is introduced, and the tension margin is relatively large. When introducing the strength coefficient, it is linearly weakened.

[0078] When calculating the basic tension Q1, the build-up current is considered, and the tension margin is relatively large. When introducing the width coefficient, it is linearly weakened.

[0079] Taking the Liuzhou Iron and Steel 1450mm production line as an example, the designed tension range is 30 - 85 KN, the thickness range is 1.2 - 12.77 mm, the width range is 800 - 1350 mm, and the highest coiling specification is 1350*4X70.

[0080] Step 1: Classify all product specifications according to the tensile strength (50 MPa).

[0081] Step 2: Determine the coefficients a, b, and c in the basic formula.

[0082] 1. Substitute the minimum grade Q195 (tensile strength 250 MPa), minimum thickness 1.2 mm, minimum tension 30 KN, and minimum width 800 mm produced by the production line into the basic formula, and we can get the following: 30 = a * 1.2 * 1.2 + b * 1.2 + c

[0083] 2. According to the maximum tension 85 KN, maximum thickness 12.7 mm, maximum width 1350 mm, and the highest coiling specification 1350 * 4X70 designed for the production line. The actual tensile strength of Q195 is 250 MPa, and the actual tensile strength of X70 is about 600 MPa. We can roughly calculate the tension of Q195 rolled with 12.7 * 800 mm as 85 * (12.7 / 4) * (800 / 1350) * (250 / 600) = 66.6 KN. Substitute it into the basic tension formula, and we can get: 66.6 = a * 12.7 * 12.7 + b * 12.7 + c

[0084] 3. According to the rolling of Q195 steel grade, the tension used for 800 * 1.2 mm is 30 KN, and the tension used for 800 * 12.7 mm is 66.6 KN. If the tension is linearly distributed, then the tension of Q195 rolled with 800 * 6.95 mm ((1.2 - 12.7) / 2 mm) is (66.6 + 30) / 2 = 48.3 KN. Since the tension formula is a parabola, the actual tension of Q195 rolled with 800 * 6.95 mm must be greater than 48.3 KN. The specific value is selected according to the coil shape quality in the actual production process of the production line. The selected value for the 1450 production line of Liugang is 58 KN. Substitute it into the basic tension formula, and we can get: 58 = a * 6.95 * 6.95 + b * 6.95 + c

[0085] Combined, the following three groups of formulas can be obtained:

[0086] 30 = a * 1.2 * 1.2 + b * 1.2 + c

[0087] 66.6 = a * 12.7 * 12.7 + b * 12.7 + c

[0088] 58 = a * 6.95 * 6.95 + b * 6.95 + c

[0089] According to the above three formulas, the three coefficients a, b, and c in the basic tension formula can be calculated. Specific tension calculation:

[0090] Tension calculation basic tension formula for the 1450 line: Q = -0.29h * h + 7.3h + 21.7,

[0091] The total tension Q = ((-0.29 * Q1 * Q1 + 7.3 * Q1 + 21.7) * (B / 300 + 2 / 3) * (B / 300 + 2 / 3));

[0092] The basic tension formula for calculating the tension of the 2032 line is Q = -0.13h * h + 6.409783h + 17.69203,

[0093] The total tension Q = ((-0.13 * h * h + 6.409783 * h + 17.69203) * (B / 300 + 2 / 3) * (Q / 300 + 2 / 3));

[0094] The tension of the present invention can be linearly calculated, avoiding the problems of tension setting jumps and the need for a large number of standard tables to be manually input in the traditional look-up table method. It also avoids the problems of width narrowing or end face misalignment caused by unreasonable tension settings when using the look-up table method.

[0095] The tension setting is more scientific and reasonable, and can achieve accurate calculation of tension under various coupling conditions of factors such as width, thickness, and steel type. It avoids the problems of large changes in coil shape or the need for manual substantial correction of tension setting values when using the original look-up table method that is divided into files according to thickness and width. The coil shape control is more stable.

[0096] The present invention simplifies the tension setting and avoids the problem that when using the original look-up table method divided into files according to thickness and width, the tension value cannot be read for new widths and new thicknesses. It completely solves the problems of waste steel and faults caused by incomplete thickness or width grading when using the look-up table method, resulting in no tension data.

[0097] Example 1:

[0098] This patent provides a method for setting the tension of a hot continuous rolling coiling unit (a method for accurately calculating the coiling tension). The technical solution of the present invention is as follows. As Figure 1 shown.

[0099] 1. Establish a grading of steel type strength.

[0100] 2. According to the lowest strength and minimum width in actual production or equipment design, construct a linearized basic formula for tension by regression according to the rolling thickness.

[0101] 3. Determine the width coefficient (width factor).

[0102] 4. Determine the strength coefficient (strength factor).

[0103] 5. Determine the total tension calculation formula according to the influence of the strength coefficient and width coefficient weighted by the basic tension formula.

[0104] The specific technical measures are as follows.

[0105] 1. Design of strength grading for each steel grade

[0106] After the production line process is solidified, according to the actual sampled tensile strength of each steel grade and combined with the strength of the actual coiling temperature of this steel grade, it is graded according to a certain strength level (30 or 50 MPa), and a strength value is assigned to each strength level. Finally, it is brought into the total tension calculation formula for tension calculation. For example: all products of a certain production line are graded according to the tensile strength gradient of 50 MPa, and can be divided into 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa... The measured tensile strength of Q355 is about 400 MPa, then it can be put into the 400 MPa grade. When calculating the total tension, the Q value in the total tension formula is directly brought in as 400 for calculation.

[0107] 2. Design of total tension calculation method

[0108] By comprehensively considering the minimum tension building current of the coiler, the actual coil shape, the narrowing situation, and based on the minimum coiling width and the lowest strength steel grade designed by the equipment, the basic tension formula is obtained by thickness regression. The formula is as follows:

[0109] Q1 = ah 2 + bh + c

[0110] In the formula: Q1 is the tension value of each thickness of the minimum width b1 and the lowest strength q1;

[0111] h is the thickness of the coiled strip;

[0112] a, b, c are constants obtained by quadratic regression calculation of the actual set tension according to the most representative steel grades (multiple) of the production line using the above formula.

[0113] Furthermore, since the basic tension Q1 considers the tension building current during calculation and has a large tension margin, the strength influence factor can be linearly weakened according to the situation when introducing it. The strength coefficient formula is as follows:

[0114] q 系 = a1Q + b1

[0115] In the formula: q 系 is the strength coefficient;

[0116] Q is the steel grade strength;

[0117] a1, b1 are constants obtained by back-calculating the actual tension of the thinnest and thickest specifications of each steel grade under the condition of meeting the coil shape for the same width.

[0118] The tension calculation formula after introducing the strength factor (strength coefficient) is as follows:

[0119] Q2 = (ah2 + bh + c) * (a1Q + b1)

[0120] Furthermore, since the base tension Q1 takes into account the build-up current during calculation and has a relatively large tension margin, when introducing the width influence factor (width coefficient), it can also be linearly weakened according to the situation. The strength coefficient formula is as follows:

[0121] b 系 = a2B + b2

[0122] In the formula: b 系 is the width coefficient;

[0123] B is the width;

[0124] a2 and b2 are constants for the same steel grade, which are obtained by back-calculating the actual tensions under the narrowest and widest specifications that meet the coil shape conditions. The total tension calculation formula after introducing the strength factor and width factor is as follows:

[0125] Q 总 = (ah 2 + bh + c) * (a1Q + b1) * (a2B + b2)

[0126] Taking the Liuzhou Steel production line with a specification of 1450mm as an example, the designed tension range is 30 - 85KN, the thickness range is 1.2 - 12.77mm, the width range is 800 - 1350mm, and the highest coiling specification is 1350 * 4X70.

[0127] First step, classify all specifications according to the tensile strength (50MPa);

[0128] Second step, determine the coefficients a, b, and c in the basic formula;

[0129] 1. Substitute the lowest grade Q195 (tensile strength 250MPa), minimum thickness 1.2mm, minimum tension 30KN, and minimum width 800mm produced by the production line into the basic formula, and we can get: 30 = a * 1.2 * 1.2 + b * 1.2 + c

[0130] 2. According to the designed maximum tension of 85KN, maximum thickness of 12.7mm, maximum width of 1350mm, and the highest coiling specification of 1350 * 4X70 for the production line. The actual tensile strength of Q195 is 250MPa, and the actual tensile strength of X70 is approximately 600MPa. We can roughly calculate the tension of Q195 with a thickness of 12.7 * 800mm as 85 * (12.7 / 4) * (800 / 1350) * (250 / 600) = 66.6KN. Substitute it into the basic tension formula, and we can get: 66.6 = a * 12.7 * 12.7 + b * 12.7 + c

[0131] 3. For the rolled Q195 steel grade, the tension used for 800*1.2 mm is 30 KN, and the tension used for 800*12.7 mm is 66.6 KN. If the tension is linearly distributed, then the tension of Q195 for rolling 800*6.95 mm ((1.2 - 12.7) / 2 mm) is (66.6 + 30) / 2 = 48.3 KN. Since the tension curve of the company is a parabola, the actual tension for rolling 800*6.95 mm Q195 must be greater than 48.3 KN. The specific value is selected according to the coil shape quality during the actual production process of the production line. The selected value for the 1450 production line of Liugang is 58 KN. Substituting it into the basic tension formula, we can get: 58 = a*6.95*6.95 + b*6.95 + c

[0132] Based on the above three points, the following three groups of formulas can be obtained:

[0133] 30 = a*1.2*1.2 + b*1.2 + c

[0134] 66.6 = a*12.7*12.7 + b*12.7 + c

[0135] 58 = a*6.95*6.95 + b*6.95 + c

[0136] According to the above three formulas, the three coefficients a, b, and c in the basic tension formula can be calculated. Finally, the total tension value can be obtained.

[0137] Table 1 shows the tension calculation and its data for the 1450 line:

[0138] Table 1

[0139]

[0140] Table 2 is the tension check for the 1450 line:

[0141] Table 2

[0142]

[0143] Table 3 shows the tension calculation and its data for the 2032 line:

[0144] Table 3

[0145]

[0146] Table 4 shows the tension check for the tension calculation of the 2032 line:

[0147] Table 4

[0148]

[0149] Technical effects:

[0150] 1. The tension can be linearly calculated, avoiding the problems of tension setting jumps and the need for a large number of standard tables to be manually input in the traditional look-up table method. It also avoids the problems of width narrowing or end face misalignment caused by unreasonable tension settings when using the look-up table method.

[0151] 2. The tension setting is more scientific and reasonable, enabling accurate calculation of tension under various coupling conditions of factors such as width, thickness, and steel type. It avoids the problems of large changes in coil shape or the need for manual significant correction of tension setting values when using the original look-up table method that is divided into grades according to thickness and width. The coil shape control is more stable.

[0152] 3. The tension setting is simplified, avoiding the problem that when using the original look-up table method divided into grades according to thickness and width, the tension value cannot be read for new widths and new thicknesses. It completely solves the problems of waste steel and failures caused by incomplete division of thickness or width grades when using the look-up table method, resulting in no tension data.

[0153] The above are only the schematic specific implementation manners of the present invention and are not intended to limit the scope of the present invention. The components of the present invention can be combined with each other under the condition of no conflict. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for setting the tension of a hot continuous rolling coiling unit, characterized in that, The method includes the following steps: Establish strength grading for steel grades, and assign a strength value to the strength level of each steel grade; According to the preset minimum strength and minimum width, construct a basic formula for tension linearization by regression based on the rolling thickness; Determine the strength coefficient and the width coefficient; According to the basic formula for tension linearization, the strength coefficient, and the width coefficient, determine the total tension calculation formula; Substitute the strength value corresponding to the strength level into the total tension calculation formula to determine the tension of the hot continuous rolling coiling unit; The basic formula for tension linearization is: Q1 = ah 2 + bh + c In the formula: Q1 is the basic tension value; the unit is KN; h is the thickness of the coiled strip steel; the unit is mm; a is a constant, b is a constant, and c is a constant.

2. The method for setting the tension of a hot continuous rolling coiling unit according to claim 1, characterized in that Establishing strength grading for steel grades includes: after the production line process is solidified, grading according to the actual sampled tensile strength of each steel grade and the strength at the actual coiling temperature of this steel grade, and assigning a strength value to the strength level of each steel grade.

3. A method for setting the tension of a hot continuous rolling coiling unit according to claim 1, characterized in that, The formula for determining the strength coefficient is: q 系 = a1Q + b1 where: q 系 is the strength coefficient; Q is the steel grade strength; the unit is MPa; Both a1 and b1 are constants obtained by back-calculating the actual tension under the condition of meeting the coil shape according to the thinnest and thickest specifications of each steel grade at the same width.

4. A method for setting the tension of a hot continuous rolling coiling unit according to claim 1, characterized in that, The formula for determining the width coefficient is: b 系 = a2B + b2 where: b 系 is the width coefficient; B is the width; the unit is mm; Both a2 and b2 are constants obtained by back-calculating the actual tension under the condition of meeting the coil shape according to the narrowest and widest specifications of the same steel grade.

5. A method for setting the tension of a hot continuous rolling coiling unit according to claim 1, characterized in that, The total tension calculation formula after introducing the strength factor and the width factor is as follows: Q 总 = (ah 2 + bh + c) * (a1Q + b1) * (a2B + b2).

6. A method for setting the tension of a hot continuous rolling coiling unit according to claim 1, characterized in that, Based on the fact that the unit tension decreases as the thickness increases and the total tension increases as the thickness increases, it is determined that the total tension has a quadratic correlation with the strip thickness. According to the minimum tension establishment current, the actual coil shape, the narrowing situation, and the equipment design capacity, a basic formula for tension linearization is regressed.

7. According to the method for setting the tension of a hot continuous rolling coiling unit described in claim 1, characterized in that The tension range of the hot continuous rolling coiling unit is 30 - 85 KN, the thickness range is 1.2 - 12.77 mm, the width range is 800 - 1350 mm, and the highest coiling specification is 1350*4X70; In the first step, grade all specifications according to the tensile strength; In the second step, determine the coefficients a, b, and c in the basic formula; According to the lowest grade produced by the production line being Q195, that is, the tensile strength of 250 MPa, the minimum thickness of 1.2 mm, the minimum tension of 30 KN, and the minimum width of 800 mm, substituting into the basic formula, we can get: 30 = a * 1.2 * 1.2 + b * 1.2 + c; According to the maximum tension of 85 KN designed for the production line, the maximum thickness of 12.7 mm, the maximum width of 1350 mm, and the highest coiling specification of 1350*4X70; the actual tensile strength of Q195 is 250 MPa, and the actual tensile strength of X70 is 600 MPa. Calculate the tension of Q195 with a thickness of 12.7 * 800 mm as 85 * (12.7 / 4) * (800 / 1350) * (250 / 600) = 66.6 KN; substituting the tension value of Q195 into the basic tension formula, we can get: 66.6 = a * 12.7 * 12.7 + b * 12.7 + c; According to the rolled Q195 steel grade, the tension used for 800*1.2mm is 30KN, and the tension used for 800*12.7mm is 66.6KN. If the tension is linearly distributed, then the tension of Q195 for rolling 800*6.95mm ((1.2 - 12.7) / 2mm) is (66.6 + 30) / 2 = 48.3KN. Since the tension formula is a parabola, the actual tension of rolling 800*6.95mm Q195 should be greater than 48.3KN. Select according to the coil shape quality in the actual production process of the production line, and determine that the selected tension value is 58KN. Substituting it into the basic tension formula, we can get: 58 = a * 6.95 * 6.95 + b * 6.95 + c The following three groups of formulas are obtained: 30 = a * 1.2 * 1.2 + b * 1.2 + c, 66.6 = a * 12.7 * 12.7 + b * 12.7 + c, 58 = a * 6.95 * 6.95 + b * 6.95 + c, Calculate the three coefficients a, b, and c in the basic tension formula according to the above three formulas.

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