A method for controlling C-curl in a planarization process

Abstract

The application discloses a C-curl treatment method in a flattening process, which comprises the following steps: collecting on-site process parameters, judging the C-curl type, calculating the difference between the upper and lower surface extensions in the width direction through geometric relation, calculating the rolling area length, calculating the difference between the upper and lower surface extensions in the length direction of the strip, calculating the stress difference between the upper and lower surfaces of the strip according to the difference between the upper and lower surface extensions in the length direction of the strip, calculating the wrap angle of the anti-chatter roller and the anti-wrinkle roller to be adjusted, calculating the height of the anti-chatter roller and the anti-wrinkle roller after adjustment according to the wrap angle of the anti-chatter roller and the anti-wrinkle roller to be adjusted, judging whether the height h q ′<h q0 after adjustment is greater than 0, and completing the adjustment if yes. The application realizes the treatment of the C-curl defect of the strip in the flattening unit, guarantees the quality and performance of the finished strip, and reduces the subsequent production instability in combination with the flattening unit equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of continuous annealing, and particularly relates to a C-curl defect treatment method in a skin pass process BACKGROUND

[0002] In the skin pass process, the factors such as roll system, friction coefficient, strip transmission and the like, and the temperature difference and uneven plastic deformation between the upper and lower surfaces of the strip cause the transverse curling of the strip (referred to as C-curl defect).

[0003] In the skin pass process, due to the inevitable uneven wear of the upper and lower roll systems, the transmission of the upper and lower double supporting rolls cannot guarantee the complete consistency of the rotating speed, and the friction coefficients of the upper and lower surfaces are different, and the like, the asymmetric rolling is formed under the comprehensive action of many asymmetric factors, thus the distribution of the unit rolling pressure, the size and distribution of the friction force on the upper and lower surfaces of the strip in the deformation zone are different, the action of the upper and lower asymmetric rolling pressure and the upper and lower asymmetric friction force will inevitably cause the uneven distribution of the tensile stress along the thickness, the metal flow difference between the upper and lower surfaces, the shear deformation in the thickness direction, and further the transverse uneven extension in the thickness direction, and the difference between the transverse extensions of the upper and lower surfaces of the strip forms the C-curl defect. Further, the large tensile stress corresponds to the small transverse extension, and the small tensile stress corresponds to the large transverse extension, when the transverse extension of the upper surface of the strip is smaller than that of the lower surface, the upper C-curl type is formed, and vice versa, the lower C-curl type is formed, the C-curl defect not only affects the overall appearance of the strip, but also causes the quality problem of the strip in the subsequent process, thereby reducing the quality grade and the yield of the product, and causing great economic loss to the unit. SUMMARY

[0004] In order to solve the C-curl phenomenon in the skin pass process of the steel plate, the technical scheme adopted by the application is as follows: a C-curl treatment method in a skin pass process, comprising the following steps

[0005] A C-curl treatment method in a skin pass process, characterized by comprising the following steps:

[0006] S1: obtaining the process parameters in the skin pass process of the strip;

[0007] S2: calculating the difference ΔB between the upper surface and the lower surface extension amount in the width direction of the strip, the difference Δl between the upper surface and the lower surface extension amount in the length direction of the strip, and the stress difference Δσ between the upper surface and the lower surface of the strip according to the process parameters in the skin pass process of the strip;

[0008] S3: calculating the wrap angle α to be adjusted of the anti-chatter roll and the anti-wrinkle roll according to the C-curl type, the difference ΔB between the upper surface and the lower surface extension amount in the width direction of the strip, the difference Δl between the upper surface and the lower surface extension amount in the length direction of the strip, and the stress difference Δσ between the upper surface and the lower surface of the strip fz , α fc ;

[0009] S4: Adjusting the wrap angle a of the anti-chatter roller and the anti-creasing roller to be adjusted fz 、a fc Adjusting the height of the anti-chatter roller and the anti-creasing roller, so that the strip changes the upper surface and lower surface stress;

[0010] S5: Measuring the camber value h of the strip after adjusting the height of the anti-chatter roller and the anti-creasing roller q ′, judging whether it meets h q ′ < h q0 , where h q0 is the set C-camber value; when h q ′ < h q0 , the treatment is over; when h q ′ ≥ h q0 , it returns to S2 to continue adjusting the camber value of the strip.

[0011] Further, the process parameters in the strip leveling process include the anti-creasing roller height H fz , the anti-chatter roller height H fc , the anti-creasing roller wrap angle a fz , the anti-chatter roller wrap angle a fc , the upper surface and lower surface friction coefficient μ of the strip, the camber type and the camber value h q of the strip at the outlet of the leveling unit, the work roller radius R, the strip thickness h0 before leveling, the strip thickness h1 after leveling, the strip width B before leveling, the front tension T0 in the leveling rolling process and the rear tension T1 in the leveling rolling process.

[0012] Further, the difference ΔB between the upper surface and lower surface extension amounts of the strip in the width direction is determined according to the central angle a c of the geometric curve and the strip thickness h1 after leveling.

[0013] Further, the strip rolling area length l is determined according to the work roller radius R, the strip thickness h0 before leveling and the strip thickness h1 after leveling.

[0014] Further, the difference Δl between the upper surface and lower surface extension amounts of the strip in the length direction is determined according to the strip width B before leveling, the difference ΔB between the upper surface and lower surface extension amounts of the strip in the width direction, the strip thickness h0 before leveling, the strip thickness h1 after leveling and the strip rolling area length l.

[0015] Further, the difference Δσ between the upper surface and lower surface stress of the strip is determined according to the difference Δl between the upper surface and lower surface extension amounts of the strip, the strip rolling area length l and the Poisson's ratio v of the strip.

[0016] Further, the wrap angle a′ of the anti-chatter roller after adjustment fz , the wrap angle a′ of the anti-creasing roller after adjustment fcAccording to the outlet warping type of the skin pass mill, based on the anti-wrinkle roller wrap angle α fz , the anti-shake roller wrap angle α fc , and the adjustment amount Δα of the wrap angle are determined.

[0017] A C-warp treatment device in a skin pass process, comprising:

[0018] An acquisition module is configured to acquire process parameters in a skin pass process of a strip steel.

[0019] A calculation module I is configured to calculate a difference ΔB between an upper surface extension and a lower surface extension in a width direction of the strip steel, a difference Δl between the upper surface extension and the lower surface extension in a length direction of the strip steel, and a stress difference Δσ between the upper surface and the lower surface of the strip steel according to the process parameters in the skin pass process of the strip steel.

[0020] A calculation module II is configured to calculate a wrap angle α fz , α fc to be adjusted of an anti-shake roller and an anti-wrinkle roller according to a C-warp type, the difference ΔB between the upper surface extension and the lower surface extension in the width direction of the strip steel, the difference Δl between the upper surface extension and the lower surface extension in the length direction of the strip steel, and the stress difference Δσ between the upper surface and the lower surface of the strip steel.

[0021] An adjustment module is configured to adjust a height of the anti-shake roller and the anti-wrinkle roller according to the wrap angle α fz , α fc to be adjusted of the anti-shake roller and the anti-wrinkle roller, so that the strip steel changes the stress of the upper surface and the lower surface.

[0022] A judgment module is configured to measure a warping value h q ' of the strip steel after adjusting the height of the anti-shake roller and the anti-wrinkle roller, and judge whether the warping value h q ' is less than a set C-warp value h q0 , wherein the warping value h q0 is the set C-warp value; when the warping value h q ' is less than the set C-warp value h q0 , the treatment is ended; and when the warping value h q ' is greater than or equal to the set C-warp value h q0 , the calculation module I is returned to continue adjusting the warping value of the strip steel.

[0023] The purpose of the present application is to provide a C-warp treatment method in a skin pass process, which can effectively treat C-warp defects of a strip steel in a skin pass process.

[0024] The present application has the following beneficial effects: compared with the prior art, the present application adjusts the height of the anti-shake roller and the anti-wrinkle roller according to the warping data measured by the existing warping instrument, and treats C-warp defects generated in the skin pass process according to the warping value.

[0025] The specific warp adjustment operation is as follows: when the strip warps, the elongation of the upper and lower surfaces is calculated based on the data measured by the warp meter, thereby obtaining the stress difference between the upper and lower surfaces. The stress on the upper and lower surfaces is changed by adjusting the height of the anti-wrinkle roller and the anti-vibration roller to complete the C-warp adjustment. This invention method is applied to the leveling unit equipment of the warp meter to realize the control of the transverse warp of the strip, improve the quality of the finished strip, bring economic benefits to enterprises, and has great promotional value. Attached Figure Description

[0026] Figure 1 This is a flowchart of the C-warping control method during the leveling process of the present invention;

[0027] Figure 2 This is a classification diagram of the C-type warp in this invention. Detailed Implementation

[0028] To further illustrate the application process of the present invention, a production record of a leveling section is used as an example to explain in detail the application of this method on site.

[0029] A method for controlling C-curve during leveling includes the following steps:

[0030] S1: Obtain process parameters during strip leveling;

[0031] S2: Based on the process parameters during strip leveling, calculate the difference ΔB between the upper and lower surfaces of the strip in the width direction, the difference Δl between the upper and lower surfaces of the strip in the length direction, and the stress difference Δσ between the upper and lower surfaces of the strip.

[0032] S3: Based on the C-type warp, the difference in elongation between the upper and lower surfaces of the strip in the width direction ΔB, the difference in elongation between the upper and lower surfaces of the strip in the length direction Δl, and the stress difference Δσ between the upper and lower surfaces of the strip, calculate the wrap angle α of the anti-vibration roller and the anti-wrinkle roller to be adjusted. fz α fc ;

[0033] S4: The wrap angle α to be adjusted between the anti-vibration roller and the anti-wrinkle roller. fz α fc The height of the anti-vibration roller and the anti-wrinkle roller is adjusted to change the stress on the upper and lower surfaces of the strip.

[0034] S5: After measuring and adjusting the height of the anti-vibration roller and the anti-wrinkle roller, the strip warp value h q ′, determine whether it conforms to h q ′<h q0 , where h q0 The set C value; when h q ′<h q0 Then the governance ends when h q ′≥hq0 If not, return to S2 to continue adjusting the camber value of the strip.

[0035] The steps S1 / S2 / S3 / S4 / S5 are executed sequentially;

[0036] Further, the process parameters in the strip leveling process include the anti-wrinkle roller height H fz , the anti-vibration roller height H fc , the anti-wrinkle roller wrap angle α fz , the anti-vibration roller wrap angle α fc , the friction coefficients μ of the upper and lower surfaces of the strip, the type and camber value h q of the strip at the outlet of the leveling unit, the work roll radius R, the strip thickness before leveling h0, the strip thickness after leveling h1, the strip width before leveling B, the front tension T0 during leveling rolling and the back tension T1 during leveling rolling.

[0037] Further, the difference ΔB between the extensions of the upper and lower surfaces of the strip in the width direction is determined according to the central angle α c of the geometric curve and the strip thickness after leveling h1, and the specific formula is as follows:

[0038]

[0039] Wherein, r is the radius of the geometric curve, α c is the central angle of the geometric curve, h1 is the strip thickness after leveling, B is the strip width before leveling, and h q is the camber value.

[0040] Further, the strip rolling area length l is determined according to the work roll radius R, the strip thickness before leveling h0, and the strip thickness after leveling h1, and the specific formula is as follows:

[0041]

[0042] Further, the difference Δl between the extensions of the upper and lower surfaces of the strip in the length direction is determined according to the strip width before leveling B, the difference ΔB between the extensions of the upper and lower surfaces of the strip in the width direction, the strip thickness before leveling h0, the strip thickness after leveling h1, and the strip rolling area length l, and the specific formula is as follows:

[0043]

[0044] Further, the stress difference Δσ between the upper and lower surfaces of the strip is determined according to the difference Δl between the extensions of the upper and lower surfaces of the strip, the strip rolling area length l, and the Poisson's ratio v of the strip, and the specific formula is as follows:

[0045]

[0046] Further, the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip are calculated according to the C-curl type, the case that the C-curl type includes upper C-curl and lower C-curl, and the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip are calculated to obtain the wrap angle α to be adjusted of the anti-vibration roller and the anti-wrinkle roller fz , α fc , and the specific formula is as follows:

[0047]

[0048] Further, the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip are calculated according to the C-curl type, the case that the C-curl type includes upper C-curl and lower C-curl, and the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip are calculated to obtain the wrap angle α to be adjusted of the anti-vibration roller and the anti-wrinkle roller fz , α fc , and the specific formula is as follows:

[0049]

[0050] A C-curl treatment device in a tempering process, comprising:

[0051] The acquisition module is configured to acquire process parameters in the tempering process of the strip.

[0052] The calculation module I is configured to calculate the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip according to the process parameters in the tempering process of the strip.

[0053] The calculation module II is configured to calculate the wrap angle α to be adjusted of the anti-vibration roller and the anti-wrinkle roller according to the C-curl type, the difference ΔB between the extension of the upper surface and the lower surface of the strip in the width direction of the strip, the difference Δl between the extension of the upper surface and the lower surface of the strip in the length direction of the strip, and the stress difference Δσ of the upper surface and the lower surface of the strip. fz , α fc ;

[0054] The adjustment module is configured to adjust the height of the anti-vibration roller and the anti-wrinkle roller according to the wrap angle α to be adjusted of the anti-vibration roller and the anti-wrinkle roller, so that the stress of the upper surface and the lower surface of the strip is changed.

[0055] The judgment module is configured to measure the curl value h q ′ of the strip after adjusting the height of the anti-vibration roller and the anti-wrinkle roller, and judge whether the curl value h q ′ is less than the set C-curl value h q0 , that is, whether h q0 ′ < h q . q0 If h q ′ < h q0 , the treatment is ended; if h fz ′ ≥ h fc , the calculation module I is returned to continue adjusting the curl value of the strip.

[0056] Example 1

[0057] As Figure 1 shown, the present application is a flatness process C-crown management method, the implementation steps are as follows.

[0058] In step S1, the on-site process parameters are collected, including the anti-wrinkle roller height H fz = 110 mm, the anti-vibration roller height H fc = 130 mm, the anti-wrinkle roller wrap angle a fz = 6.88°, the anti-vibration roller wrap angle a fc = 8.6°, the upper and lower surface friction coefficient m = 0.1, the flatness unit outlet warping type is downward warping, the warping value h q = 10 mm, the work roller radius R = 200 mm, the strip thickness before and after flattening h0 = 1.2 mm, h1 = 1 mm, the strip width before flattening B = 1000 mm, the front tension T0 = 50 MPa during the flattening rolling process, and the rear tension T1 = 60 MPa.

[0059] In step S2, according to the process parameters in the strip flattening process, the difference between the upper and lower surface extensions of the strip in the width direction is calculated, and the difference between the upper and lower surface extensions of the strip in the length direction is calculated. The difference between the upper and lower surface stress of the strip is calculated.

[0060] S21: According to the measured warping value, the difference between the upper and lower surface extensions in the width direction is calculated by geometric relationship, where r is the radius of the geometric curve, a c is the central angle of the geometric curve:

[0061]

[0062] After calculation: AB = 0.079988 mm;

[0063] In step S22, the rolling area length l is calculated:

[0064]

[0065] After calculation: l = 6.325 mm;

[0066] In step S23, the difference between the upper and lower surface extensions of the strip in the length direction is calculated:

[0067]

[0068] After calculation: Dl = 1.2644 mm;

[0069] In step S24, the difference between the upper and lower surface stress of the strip is calculated according to the difference between the upper and lower surface extensions of the strip in the length direction:

[0070]

[0071] Calculation shows that Δσ = 46.132 MPa;

[0072] In step S3, the wrap angle α to be adjusted between the anti-vibration roller and the anti-wrinkle roller is calculated based on the C-type warping, the difference ΔB between the upper and lower surfaces of the strip in the width direction, the difference Δl between the upper and lower surfaces of the strip in the length direction, and the stress difference Δσ between the upper and lower surfaces of the strip. fz α fc :

[0073]

[0074] Calculated:

[0075] In step S4, the wrap angle α between the anti-vibration roller and the anti-wrinkle roller is adjusted. fz α fc The heights of the anti-vibration rollers and anti-wrinkle rollers are adjusted to change the stress on the upper and lower surfaces of the strip.

[0076]

[0077] Calculated:

[0078] In step S5, the height of the anti-vibration roller and the anti-wrinkle roller is adjusted to... Measure the warp value h of the strip after adjustment q = 3.8 mm, h q If ′ < 5mm, the adjustment is complete.

[0079] Example 2

[0080] like Figure 1 As shown, the present invention provides a method for controlling C-curve during the leveling process, and the implementation steps are as follows.

[0081] In step S1, on-site process parameters are collected, including the height H of the anti-wrinkle roller. fz =110mm, anti-vibration roller height H fc =130mm, anti-wrinkle roller wrap angle α fz =6.88°, anti-vibration roller wrap angle α fc =8.6°, friction coefficient of upper and lower surfaces μ=0.1, warping type of the leveling unit outlet is upward warping, warping value h q =12mm, work roll radius R=200mm, strip thickness before and after leveling h0=1.2mm, h1=1mm, strip width before leveling B=1000mm, tension before and after leveling rolling T0=50MPa, T1=60MPa.

[0082] In step S2, the difference ΔB between the surface and the lower surface extension in the width direction of the strip is calculated according to the process parameters in the strip leveling process, the difference Δl between the upper and lower surface extension of the strip in the length direction is calculated, and the stress difference Δσ between the upper and lower surfaces of the strip is calculated;

[0083] S21: According to the measured camber value h q , the difference ΔB between the upper and lower surface extension in the width direction is calculated through geometric relationship, where r is the radius of the geometric curve, and α c is the central angle of the geometric curve:

[0084]

[0085] After calculation: ΔB = 0.095923 mm;

[0086] In step SS22, the rolling area length l is calculated:

[0087]

[0088] After calculation: l = 6.325 mm;

[0089] In step S23, the difference Δl between the upper and lower surface extension of the strip in the length direction is calculated:

[0090]

[0091] After calculation: Δl = 1.2643 mm;

[0092] In step S24, the stress difference Δσ between the upper and lower surfaces of the strip is calculated according to the difference between the upper and lower surface extension of the strip in the length direction:

[0093]

[0094] After calculation: Δσ = 46.128 MPa;

[0095] In step S3, the wrap angles α fz , α fc to be adjusted of the anti-chatter roller and the anti-wrinkle roller are calculated according to the C camber type, the difference ΔB between the surface and the lower surface extension in the width direction of the strip, the difference Δl between the upper and lower surface extension of the strip in the length direction, and the stress difference Δσ between the upper and lower surfaces of the strip:

[0096]

[0097] After calculation:

[0098] In step S4, the wrap angles α fz , α fcThe height of the anti-vibration roller and the anti-wrinkle roller is adjusted, so that the strip changes the upper surface and lower surface stress, and the formula is as follows:

[0099]

[0100] After calculation:

[0101] In step S5, the height of the anti-vibration roller and the anti-wrinkle roller is adjusted to The camber value h of the strip after adjustment is measured q ′ = 4.2mm, h q ′ < 5mm is established, and the adjustment is completed.

[0102] The above is only used to illustrate the technical solutions of the present application, and the simple modification or equivalent replacement of the technical solutions of the present application by the ordinary skilled in the art does not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A method for controlling C-curve during leveling, characterized in that, Includes the following steps: S1: Obtain process parameters during strip leveling; S2: Based on the process parameters during strip leveling, calculate the difference in elongation between the upper and lower surfaces in the strip width direction. The difference in elongation between the upper and lower surfaces of the strip in the length direction Stress difference between the upper and lower surfaces of the strip ; S3: Based on the C-curve type, the difference in elongation between the upper and lower surfaces along the strip width direction. The difference in elongation between the upper and lower surfaces of the strip in the length direction Stress difference between the upper and lower surfaces of the strip Calculate the wrap angle to be adjusted for the anti-vibration roller and the anti-wrinkle roller. , ; S4: Adjust the wrap angle of the anti-vibration roller and the anti-wrinkle roller. , The height of the anti-vibration roller and the anti-wrinkle roller is adjusted to change the stress on the upper and lower surfaces of the strip. S5: After measuring and adjusting the height of the anti-vibration roller and the anti-wrinkle roller, measure the warp value of the strip. Determine whether it meets the requirements. ,in The set C-value; when Then the governance ends, when If the time is right, return to S2 and continue adjusting the strip warp value.

2. The method for controlling C-curve during leveling according to claim 1, characterized in that, The process parameters for the strip leveling process include the height of the anti-wrinkle roller. Anti-vibration roller height Anti-wrinkle roller wrap angle Anti-vibration roller wrap angle The coefficient of friction between the upper and lower surfaces of the strip Types and values ​​of warpage at the outlet of the leveling unit Work roll radius , strip thickness before leveling , strip thickness after leveling , width of strip before leveling Pre-tension during leveling rolling Post-tension during leveling and rolling .

3. The method for controlling C-curve during leveling according to claim 1, characterized in that: The difference between the upper and lower surface elongations in the width direction of the strip According to the central angle of the geometric curve , strip thickness after leveling To be confirmed.

4. The method for controlling C-curve during leveling according to claim 1, characterized in that: Strip rolling zone length Based on the radius of the work roll , strip thickness before leveling , strip thickness after leveling To be confirmed.

5. The method for controlling C-curve during leveling according to claim 4, characterized in that: The difference in elongation between the upper and lower surfaces of the strip along its length direction Based on the width of the strip before leveling The difference between the upper and lower surface elongation in the width direction of the strip , strip thickness before leveling , strip thickness after leveling and strip rolling zone length To be confirmed.

6. The method for controlling C-curve during leveling according to claim 4, characterized in that: The stress difference between the upper and lower surfaces of the strip Based on the difference in elongation between the upper and lower surfaces of the strip Length of strip rolling zone Poisson's ratio of strip steel To be confirmed.

7. The method for controlling C-curve during leveling according to claim 1, characterized in that: The wrap angle of the anti-vibration roller after adjustment The wrap angle after adjusting the anti-wrinkle roller Based on the type of warpage at the leveling unit outlet, and the wrap angle of the anti-wrinkle roller... Anti-vibration roller wrap angle Adjustment amount of the wrap angle To be confirmed.

8. A device for controlling C-curve during leveling, characterized in that, include: Acquisition module: used to acquire process parameters during strip leveling; Calculation Module I: Based on the process parameters during strip leveling, calculate the difference in elongation between the upper and lower surfaces of the strip in the width direction. The difference in elongation between the upper and lower surfaces of the strip in the length direction Stress difference between the upper and lower surfaces of the strip ; Calculation Module II: Used to calculate the difference between the upper and lower surface elongation in the strip width direction based on the C-curve type. The difference in elongation between the upper and lower surfaces of the strip in the length direction Stress difference between the upper and lower surfaces of the strip Calculate the wrap angle to be adjusted for the anti-vibration roller and the anti-wrinkle roller. , ; Adjustment module: used to adjust the wrap angle of the anti-vibration roller and the anti-wrinkle roller. , The height of the anti-vibration roller and the anti-wrinkle roller is adjusted to change the stress on the upper and lower surfaces of the strip. Judgment module: Used to measure the warp value of the strip after adjusting the height of the anti-vibration roller and the anti-wrinkle roller. Determine whether it meets the requirements. ,in The set C-value; when Then the governance ends, when If the time is not met, return to calculation module I and continue adjusting the strip warp value.

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