Calculation method for strip steel head plate shape defect length

Abstract

The invention relates to a method for calculating strip steel head plate shape defect length, and belongs to the technical field of rolled steel plate shape control methods. According to the technical scheme, the total length and width of strip steel and the radius of a coiled steel coil are determined, and the radius of a pinch roll is determined; determining the distance between the position of the steel coil on the pinch roll and the center of the pinch roll when a wave shape appears after the steel coil uncoiled by the temper mill is flattened; calculating the total volume of the steel coil to obtain the volume of the residual cylinder when the wave shape appears, and calculating to obtain the length of the strip steel head defect; and drawing the appearance and disappearance positions of the wave shape after uncoiling, measuring the actual length by using a measuring tape, and comparing the difference between the actual length and the calculated length. The method has the beneficial effects that the length of the defect at the head of the steel coil can be evaluated by simply measuring the thickness of the defect position of the steel coil on the pinch roll through the product basic data which can be inquired in the production data report, so that the control on the product quality is greatly improved, the production rhythm of a hot-rolled product is improved, and the working efficiency of a temper mill is improved.

Description

Technical Field

[0001] This invention relates to a method for calculating the length of strip head shape defects, belonging to the technical field of strip shape control methods in steel rolling. Background Technology

[0002] When hot-rolling specialty steels, especially duplex steels and wheel steels, waviness and double-sided waviness frequently occur at the head position, and the edge waviness is particularly severe. In some cases, the waviness height can reach 100 mm. Generally, if the waviness height exceeds 30 mm, a leveling process is required. To reduce the length of defects at the head of specialty steels and improve product quality, it is necessary to conduct defect assessments on the quality of steel coils. In the past, measurements could only be made by visually estimating the length of head defects. However, measuring the length of head plate shape defects would significantly reduce the working efficiency of the leveling machine. Summary of the Invention

[0003] The purpose of this invention is to provide a method for calculating the length of strip head defects. By using the basic product data that can be found in the production data report and by simply measuring the thickness of the steel coil at the defect location on the pinch roll, the length of the steel coil head defect can be evaluated. This greatly improves the control of product quality, speeds up the production of hot-rolled products, and increases the working efficiency of the leveling machine, effectively solving the above-mentioned problems in the background technology.

[0004] The technical solution of this invention is: a method for calculating the length of a strip head shape defect, comprising the following steps: S1: Determine the total length and width of the strip and the radius R1 of the coiled steel by querying the production data report, and determine the radius r of the pinch roll by measurement; S2: Determine the distance R2 between the position of the steel coil on the pinch roller and the center of the pinch roller when a wavy shape appears after the steel coil is uncoiled and laid flat on the leveler; S3: Calculate the total volume of the steel coil using the measurement data from steps S1 and S2, and obtain the volume of the remaining cylinder when the wavy shape appears; S4: Based on the principle that the volume of the steel coil remains unchanged before and after uncoiling, T is obtained. 剩余圆柱 =T 浪板 Since the height of the plate and strip is the same as the height of the remaining part of the cylinder, then T 板 / T 浪板 =T 钢卷 / T 剩余圆柱 ; S5: Based on the formula in step S4, the ratio of the total length of the steel coil to the total length of the strip with severe waviness is ΠR. 总 2 / ΠR 浪 2 S 总 / S 浪 =R 总2 / R 浪 2 The length S of the defect at the head of the strip was obtained after calculation. 浪 ; S6: Use a marker to mark the positions where the wavy lines appear and disappear after unrolling, and use a measuring tape to measure their length S. 实际 With S in step S5 浪 Compare the differences between the two.

[0005] In step S1, the diameter of the coiled steel includes the central hollow portion. The total volume of the cylinder formed by the coil is calculated using the total length and width of the strip and the radius of the coiled steel. The actual volume of the coil excluding the central hollow portion is calculated using the radius of the leveling machine's pinch rolls. The volume of the hollow cylinder = the volume of the entire cylinder - the volume of the pinch rolls, i.e., T. 剩余圆柱 =T 圆柱 -T 夹送辊 .

[0006] In step S3, T 钢卷 =Π(R1 2 -r 2 h, T 剩余圆柱 =Π(R2 2 -r 2 )h, where T 钢卷 T represents the total volume of the steel coil. 剩余圆柱 This represents the volume of the remaining cylinder when a wavy shape appears.

[0007] In step S4, T 板 =T 钢卷 =Π(R1 2 -r 2 h, T 浪板 =T 剩余圆柱 =Π(R2 2 -r 2 )h.

[0008] In step S5, the head wave length S 浪 =S 总 *(R2) 2 -r 2 ) / (R1 2 -r 2 ).

[0009] The beneficial effects of this invention are: by using the basic product data that can be found in the production data report, and by simply measuring the thickness of the defect location of the steel coil on the pinch roll, the length of the defect at the head of the steel coil can be evaluated, which greatly improves the control of product quality, speeds up the production rhythm of hot-rolled products, and improves the working efficiency of the leveling machine. Attached Figure Description

[0010] Figure 1 This is a diagram showing the head warping of the duplex steel during uncoiling at the leveling machine of this invention. Figure 2 This is a diagram showing the specific situation when the clamping rollers of the leveling machine of the present invention are unwound; Figure 3 This is a plan view of the steel coil uncoiling mandrel of the leveling machine of the present invention; In the diagram: pinch roller 1, steel coil 2, shaft 3. Detailed Implementation

[0011] To make the purpose, technical solutions, and advantages of the invention's embodiments clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only a small part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0012] A method for calculating the length of a strip head defect includes the following steps: S1: Determine the total length and width of the strip and the radius R1 of the coiled steel by querying the production data report, and determine the radius r of the pinch roll by measurement; S2: Determine the distance R2 between the position of the steel coil on the pinch roller and the center of the pinch roller when a wavy shape appears after the steel coil is uncoiled and laid flat on the leveler; S3: Calculate the total volume of the steel coil using the measurement data from steps S1 and S2, and obtain the volume of the remaining cylinder when the wavy shape appears; S4: Based on the principle that the volume of the steel coil remains unchanged before and after uncoiling, T is obtained. 剩余圆柱 =T 浪板 Since the height of the plate and strip is the same as the height of the remaining part of the cylinder, then T 板 / T 浪板 =T 钢卷 / T 剩余圆柱 ; S5: Based on the formula in step S4, the ratio of the total length of the steel coil to the total length of the strip with severe waviness is ΠR. 总 2 / ΠR 浪 2 S 总 / S 浪 =R 总 2 / R 浪 2 The length S of the defect at the head of the strip was obtained after calculation. 浪 ; S6: Use a marker to mark the positions where the wavy lines appear and disappear after unrolling, and use a measuring tape to measure their length S. 实际 With S in step S5 浪 Compare the differences between the two.

[0013] In step S1, the diameter of the coiled steel includes the central hollow portion. The total volume of the cylinder formed by the coil is calculated using the total length and width of the strip and the radius of the coiled steel. The actual volume of the coil excluding the central hollow portion is calculated using the radius of the leveling machine's pinch rolls. The volume of the hollow cylinder = the volume of the entire cylinder - the volume of the pinch rolls, i.e., T. 剩余圆柱 =T 圆柱 -T 夹送辊 .

[0014] In step S3, T 钢卷 =Π(R1 2 -r 2 h, T 剩余圆柱 =Π(R2 2 -r 2 )h, where T 钢卷 T represents the total volume of the steel coil. 剩余圆柱 This represents the volume of the remaining cylinder when a wavy shape appears.

[0015] In step S4, T 板 =T 钢卷 =Π(R1 2 -r 2 h, T 浪板 =T 剩余圆柱 =Π(R2 2 -r 2 )h.

[0016] In step S5, the head wave length S 浪 =S 总 *(R2) 2 -r 2 ) / (R1 2 -r 2 ). Example

[0017] The length of the bend at the head of a roll of duplex steel is used as a case study for evaluation.

[0018] Known parameters: (1) The total length of the steel coil is LP = 609 m; (2) If the outer diameter of the steel coil is D=1906, then the radius of the entire steel coil is R1=1906 / 2=953 mm; (3) The pinch roller has a diameter d = 760 mm and a radius r = 380 mm; (4) The diameter of the steel coil at the location of the defect is 950 mm. Therefore, the radius of the location of the defect is R2 = 950 / 2 = 475 mm.

[0019] T 板 =T 钢卷 =Π(R1 2 -r 2 h, T 浪板 =T 剩余圆柱 =Π(R2 2 -r 2 h Using T 板 / T 浪板 =T 圆柱 / T 剩余圆柱 S is obtained 总 / S 浪 =ΠR 总 2 / ΠR 浪 2 Then S 浪 =S 总 *(R2) 2 -r 2 ) / (R1 2 -r 2 ) = 609 * (475) 2 -380 2 ) / (953 2 -380 2 =65.09 m, the defect rate is 65.09 / 609=10.7%.

[0020] After uncoiling the entire steel coil, mark the location where the wavy pattern appears with a marker. Due to the severe warping at the head of the dual-phase steel, the warping usually extends to the strip head. Measure the length S from the location where the warping appears to the strip head with a tape measure. 实际 =68 m, then the accuracy rate of the defect length at the head of the steel coil is 65.09 / 68=95.7%.

[0021] The following is the calculation of the head bend length for the WL980X:

[0022] Example 2: The length of the double-sided wave at the head of a coil of wheel steel is taken as a case study.

[0023] Known parameters: (1) The total length of the steel coil LP = 430 m; (2) The outer diameter of the steel coil is D=1826, then the radius of the entire steel coil is R1=1826 / 2=913 mm; the diameter of the pinch roll is d=760 mm, and the radius is r=380 mm. (3) The diameter of the steel coil at the location of the defect is 950 mm. Therefore, the radius of the location of the defect is R2 = 913 / 2 = 466.5 mm.

[0024] T 板 =T 钢卷 =Π(R1 2 -r 2 h, T 浪板 =T 剩余圆柱 =Π(R2 2 -r 2 h Using T 板 / T 浪板 =T 圆柱 / T 剩余圆柱 S is obtained 总 / S 浪 =ΠR 总 2 / ΠR 浪 2 Then S 浪 =S 总 *(R2) 2 -r 2 ) / (R1 2 -r 2 =430*(475) 2 -380 2 ) / (466.5) 2 -380 2 =98.64 m, the defect rate is 98.64 / 430=22.94%.

[0025] After uncoiling the entire steel coil, mark the location where the wavy pattern appears with a marker. Due to the severe double-sided wavy pattern at the wheel steel head, the double-sided wavy pattern usually extends to the head of the strip. Measure the length S from the location where the wavy pattern appears to the head of the strip. 实际 =106 m, then the accuracy rate of the defect length at the head of the steel coil is 98.64 / 106=93.1%.

[0026] The following is the calculation of the double-sided wave length of the 650CL steel head:

[0027] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for calculating the length of a strip head plate-shaped defect, characterized in that... Includes the following steps: S1: Determine the total length and width of the strip and the radius R1 of the coiled steel by querying the production data report, and determine the radius r of the pinch roll by measurement; S2: Determine the distance R2 between the position of the steel coil on the pinch roller and the center of the pinch roller when a wavy shape appears after the steel coil is uncoiled and laid flat on the leveler; S3: Calculate the total volume of the steel coil using the measurement data from steps S1 and S2, and obtain the volume of the remaining cylinder when the wavy shape appears; S4: Based on the principle that the volume of the steel coil remains unchanged before and after uncoiling, T is obtained. 剩余圆柱 =T 浪板 Since the height of the plate and strip is the same as the height of the remaining part of the cylinder, then T 板 / T 浪板 =T 钢卷 / T 剩余圆柱 ; S5: Based on the formula in step S4, the ratio of the total length of the steel coil to the total length of the strip with severe waviness is ΠR. 总 2 / ΠR 浪 2 S 总 / S 浪 =R 总 2 / R 浪 2 The length S of the defect at the head of the strip was obtained after calculation. 浪 ; S6: Use a marker to mark the positions where the wavy lines appear and disappear after unrolling, and use a measuring tape to measure their length S. 实际 With S in step S5 浪 Compare the differences between the two.

2. The method for calculating the length of the strip head shape defect according to claim 1, characterized in that: In step S1, the diameter of the coiled steel includes the central hollow portion. The total volume of the cylinder formed by the coil is calculated using the total length and width of the strip and the radius of the coiled steel. The actual volume of the coil excluding the central hollow portion is calculated using the radius of the leveling machine's pinch rolls. The volume of the hollow cylinder = the volume of the entire cylinder - the volume of the pinch rolls, i.e., T. 剩余圆柱 =T 圆柱 -T 夹送辊 .

3. The method for calculating the length of the strip head shape defect according to claim 1, characterized in that: In step S3, T 钢卷 =Π(R1 2 -r 2 h, T 剩余圆柱 =Π(R2 2 -r 2 )h, where T 钢卷 T represents the total volume of the steel coil. 剩余圆柱 This represents the volume of the remaining cylinder when a wavy shape appears.

4. The method for calculating the length of the strip head shape defect according to claim 1, characterized in that: In step S4, T 板 =T 钢卷 =Π(R1 2 -r 2 h, T 浪板 =T 剩余圆柱 =Π(R2 2 -r 2 )h.

5. The method for calculating the length of the strip head shape defect according to claim 1, characterized in that: In step S5, the head wave length S 浪 =S 总 *(R2) 2 -r 2 ) / (R1 2 -r 2 ).

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