Process optimization method for controlling roughness of strip steel of temper mill

Abstract

The invention discloses a process optimization method for controlling roughness of strip steel of a temper mill. The process optimization method comprises the following steps: S1, collecting process parameters related to equipment; s2, carrying out unit division on the roller body lengths of the supporting roller and the working roller and the width of the strip and defining related parameters; s3, the total rolling pressure P is calculated; s4, if the total rolling pressure P is smaller than the maximum set value, namely P is smaller than or equal to PMAX, the step S5 is executed, and otherwise, the step S12 is executed; s5, calculation of intermediate parameters is given; s6, calculating strip steel outlet thickness distribution hi; s7, the elongation distribution epsilon i of the strip steel in the width direction is calculated; s8, calculating a roughness distribution value Rasi in the width direction of the strip steel; s9, calculating a strip steel roughness control objective function F (X); s10, if F (X) is smaller than or equal to F (X) 0, entering the step S11; s11, if epsilon is smaller than or equal to epsilon max, the step S12 is executed, and otherwise, epsilon is made to be equal to epsilon max, and then the step S12 is executed; and S12, calculation is ended, and the optimal elongation epsilon is output. The strip steel flattening precision and efficiency are improved.

Description

Technical Field

[0001] This invention relates to strip steel leveling technology in the metallurgical industry, and more specifically, to a process optimization method for controlling the roughness of strip steel in a leveling unit. Background Technology

[0002] A sizing unit is a piece of equipment used to process metal strips, primarily for adjusting their flatness and surface quality. In the metal processing industry, metal strips such as steel and aluminum strips typically require sizing during production to ensure they meet specific flatness and surface requirements. A sizing unit usually consists of a set of rollers that flatten and stretch the metal strip by adjusting the roller gap and pressure, thereby improving its surface quality and flatness. During the sizing process, the metal strip passes through a channel formed by the rollers, undergoing a series of roller gap adjustments and pressure controls to ultimately achieve the desired flatness. Sizing units play a crucial role in the metal processing industry, especially in the production of high-precision metal strips and products requiring high surface quality. By precisely controlling the roller gap, roller pressure, and other parameters, sizing units can effectively improve the flatness and surface quality of metal strips, increasing product quality and production efficiency.

[0003] A strip leveling unit is a device used to process metal strips. It achieves strip leveling and improves surface quality by adjusting the roll gap and pressure. Strip roughness refers to the degree of unevenness of the strip surface. For applications requiring high surface quality, such as automotive manufacturing and electronics, controlling strip roughness is crucial.

[0004] Traditional strip leveling units typically employ experience-based adjustment methods, where operators adjust the roll gap and pressure based on experience and observation. This method suffers from inaccurate adjustments and low efficiency. Summary of the Invention

[0005] In view of the empirical adjustment method used for strip roughness in existing leveling mills, and in combination with the rolling process characteristics of leveling mills, a process optimization method for controlling strip roughness in leveling mills is proposed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A process optimization method for controlling the roughness of strip steel in a leveling unit includes the following steps:

[0008] S1, collect relevant process parameters of the equipment;

[0009] S2, divide the support roller, work roller body length and strip width into units and define relevant parameters;

[0010] S3, calculate the total rolling pressure P;

[0011] S4, if the total rolling pressure P is less than the maximum set value, i.e., P ≤ P MAX If yes, proceed to step S5; otherwise, proceed to step S12.

[0012] S5 provides the calculation of intermediate parameters;

[0013] S6. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i ;

[0014] S7, Calculate the elongation distribution ε in the width direction of the strip. i ;

[0015] S8, Calculate the roughness distribution value Ra in the width direction of the strip. si ;

[0016] S9, set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control;

[0017] S10. If F(X)≤F(X)0 is satisfied, proceed to step S11. Otherwise, adjust the elongation rate, let ε=ε+Δε and return to step S3.

[0018] S11, if ε≤ε max If yes, proceed to step S12; otherwise, let ε = ε. max Then proceed to step S12;

[0019] S12, end the calculation and output the optimal elongation ε.

[0020] Preferably, the process parameters include the support roller diameter D. b Support roller body length L B Work roll diameter D w Length L of the working roll body W Friction coefficient μ, maximum rolling force P MAX The lever arm l of the support roller BL The lever arm of the work roller l WL Rolling speed V, deformation resistance influence coefficient k3, strip yield strength σ s Strain rate coefficient α, strip inlet thickness H, strip inlet thickness distribution H i Strip exit thickness h, strip width b, front tension T1, back tension T0, strip deformation resistance k, length per unit Δx, Poisson's ratio v, elastic modulus E, work roll mileage L, and original surface roughness Ra of the strip. s0 Surface roughness Ra of the working roll s0 Target roughness value Ra in the width direction of the strip s′, Elongation increase Δε, Maximum elongation ε max .

[0021] Preferably, step S2 specifically includes:

[0022] The length of the support roller is divided laterally into... The length of the working roller is divided into several units, with the roller body laterally divided into... Each unit divides the width of the strip laterally into units. Unit;

[0023] Let N = n1 and set x i =(i-(N+1) / 2)Δx is the distance of the i-th unit from the center of the roll, and the initial elongation value ε is set to 0.

[0024] Preferably, in step S3, the total rolling pressure P is calculated using the Roberts formula:

[0025]

[0026] Where f represents the rolling force per unit width;

[0027] l represents the contact arc length between the roll and the strip in the rolling deformation zone;

[0028] a0 and a1 represent the influence coefficients of leveling steel grade and working conditions, -10.0≤a0≤10.0, -6.0≤a1≤6.0;

[0029] σ P Indicates the current deformation resistance;

[0030] e represents the strain rate;

[0031] k1 and k2 represent the front and back tension weighting coefficients, with k1 = k2 = 0.5.

[0032] Preferably, in step S5, the intermediate parameters include the influence function of the deflection changes of the work roll, intermediate roll, and support roll caused by the load, the influence function of the left and right bending roll forces on the deflection changes of the work roll, intermediate roll, and support roll, and the roll-to-roll flattening coefficients of the work roll and intermediate roll, the intermediate roll and support roll, and the strip and work roll.

[0033] Preferably, the intermediate parameters are calculated as follows:

[0034]

[0035]

[0036] Among them, a ij c ijThese represent the deflection influence coefficients of the i-th unit of the work roll and the support roll on the j-th unit, respectively.

[0037] a wi a bi These represent the influence coefficients of the bending force and the supporting force of the i-th unit work roll, respectively.

[0038] K wb K and K′ represent the inter-roll flattening coefficients of the work roll and support roll, and the strip and work roll, respectively;

[0039] x=(i-(N+1) / 2)Δx, x'=(j-(N+1) / 2)Δx.

[0040] Preferably, in step S6, the strip exit thickness distribution h is calculated. i Specifically as follows:

[0041]

[0042] Among them, f wi f bi These represent the deflection of the working roller and the deflection of the support roller in the i-th unit, respectively.

[0043] q wbj q zj These represent the inter-roll force and rolling force of the j-th unit's work roll and support roll, respectively.

[0044] Preferably, in step S7, the elongation distribution ε in the width direction of the strip is calculated. i Specifically as follows:

[0045]

[0046] Among them, h i This indicates the thickness distribution at the strip exit.

[0047] Preferably, in step S8, the roughness distribution value Ra in the width direction of the strip is calculated according to the strip roughness calculation formula. si Specifically as follows:

[0048]

[0049] Where, ε i This indicates the elongation distribution along the width of the strip.

[0050] Preferably, in step S9, the objective function F(X) for strip roughness control is calculated as follows:

[0051]

[0052] The present invention provides a process optimization method for controlling the roughness of strip steel in a leveling unit. By using advanced control algorithms and sensing technology, combined with the process characteristics of the leveling unit and a strip steel roughness calculation model suitable for the unit, it replaces the existing outdated empirical process adjustment method. It comprehensively controls the roughness of each point on the transverse side of the strip steel, with the optimal objective function as the control target. By setting the elongation rate of the leveled strip steel, the accuracy and efficiency of strip steel leveling are ultimately improved. Attached Figure Description

[0053] Figure 1 This is a flowchart illustrating the process optimization method of the present invention. Detailed Implementation

[0054] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0055] Combination Figure 1 As shown, the present invention provides a process optimization method for controlling the roughness of strip steel in a leveling unit, comprising the following steps:

[0056] S1, Collect relevant process parameters for the equipment, including the support roller diameter D. b Support roller body length L B Work roll diameter D w Length L of the working roll body W Friction coefficient μ, maximum rolling force P MAX The lever arm l of the support roller BL The lever arm of the work roller l WL Rolling speed V, deformation resistance influence coefficient k3, strip yield strength σ s Strain rate coefficient α, strip inlet thickness H, strip inlet thickness distribution H i Strip exit thickness h, strip width b, front tension T1, back tension T0, strip deformation resistance k, length per unit Δx, Poisson's ratio v, elastic modulus E, work roll mileage L, and original surface roughness Ra of the strip. s0 Surface roughness Ra of the working roll s0 Target roughness value Ra in the width direction of the strip s ′, Elongation increase Δε, Maximum elongation ε max .

[0057] S2 divides the support roller, work roller body length, and strip width into units and defines relevant parameters, specifically including:

[0058] The length of the support roller body is divided laterally into The length of the work roll body is divided into units, which are transversely divided into sections. Each unit divides the width of the strip laterally into units. Unit;

[0059] Let N = n1 and set x i =(i-(N+1) / 2)Δx is the distance of the i-th unit from the center of the roll, and the initial elongation value ε is set to 0.

[0060] S3, the total rolling pressure P is calculated using the Roberts formula, as follows:

[0061]

[0062] Where f represents the rolling force per unit width;

[0063] l represents the contact arc length between the roll and the strip in the rolling deformation zone;

[0064] a0 and a1 represent the influence coefficients of leveling steel grade and working conditions, -10.0≤a0≤10.0, -6.0≤a1≤6.0;

[0065] σ P Indicates the current deformation resistance;

[0066] e represents the strain rate;

[0067] k1 and k2 represent the front and back tension weighting coefficients, with k1 = k2 = 0.5.

[0068] S4, if the total rolling pressure P is less than the maximum set value, i.e., P ≤ P MAX If yes, proceed to step S5; otherwise, proceed to step S12.

[0069] S5 provides the influence functions of load-induced deflection changes in the work roll, intermediate roll, and support roll; the influence functions of left and right bending roll forces on the deflection changes in the work roll, intermediate roll, and support roll; and the calculation methods for intermediate parameters such as the roll-to-roll flattening coefficient between the work roll and intermediate roll, the intermediate roll and support roll, and the strip and work roll.

[0070]

[0071]

[0072] Among them, a ij c ij These represent the deflection influence coefficients of the i-th unit of the work roll and the support roll on the j-th unit, respectively.

[0073] a wi a bi These represent the influence coefficients of the bending force and the supporting force of the i-th unit work roll, respectively.

[0074] Kwb K and K′ represent the inter-roll flattening coefficients of the work roll and support roll, and the strip and work roll, respectively;

[0075] x=(i-(N+1) / 2)Δx, x'=(j-(N+1) / 2)Δx.

[0076] S6. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i The specific calculations are as follows:

[0077]

[0078] Among them, f wi f bi These represent the deflection of the working roller and the deflection of the support roller in the i-th unit, respectively.

[0079] q wbj q zj These represent the inter-roll force and rolling force of the j-th unit's work roll and support roll, respectively.

[0080] S7, Calculate the elongation distribution ε in the width direction of the strip. i The details are as follows:

[0081]

[0082] Among them, h i This indicates the thickness distribution at the strip exit.

[0083] S8, Calculate the roughness distribution value Ra in the width direction of the strip. si The details are as follows:

[0084]

[0085] Where, ε i This indicates the elongation distribution along the width of the strip.

[0086] S9. Set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control, as follows:

[0087]

[0088] S10. If F(X)≤F(X)0 is satisfied, proceed to step S11. Otherwise, adjust the elongation rate, let ε=ε+Δε and return to step S3.

[0089] S11, if ε≤ε max If yes, proceed to step S12; otherwise, let ε = ε. max Then proceed to step S12.

[0090] S12, end the calculation and output the optimal elongation ε.

[0091] Example 1

[0092] This embodiment 1 provides a process optimization method for controlling the roughness of strip steel in a leveling unit, specifically including the following steps:

[0093] S1, Collect relevant equipment and process parameters: support roller diameter D b The support roller body length is 1100mm. B The working roll diameter is 2060mm. w The length of the work roll body is 450mm. W The diameter is 2100 mm, the friction coefficient μ is 0.214, and the maximum rolling force P is... MAX The lever arm of the support roller is 15000kN. BL The lever arm of the work roll is 1500mm. WL The strip length is 1500 mm, the rolling speed V is 118 m / min, the deformation resistance influence coefficient k3 is 1.155, and the strip yield strength σ s The strain pressure is 179 MPa, the strain rate coefficient a is 4.4, the strip inlet thickness H is 0.641 mm, and the strip inlet thickness distribution H... i for The strip exit thickness h is 0.635 mm, the strip width b is 1003 mm, the initial tension T1 is 35.33 kN, the post-tension T0 is 32.64 kN, the strip deformation resistance k is 168 MPa, the length of each unit Δx is 68 mm, the Poisson's ratio v is 0.3, the elastic modulus E is 210000 MPa, the work roll rolling mileage L is 154 km, and the original surface roughness Ra of the strip is... s0 The surface roughness Ra of the work roll is 1.77 μm. r0 The target roughness value Ra is 1.3 μm in the width direction of the strip. s The value is 1.005 μm, the increase in elongation Δε is 0.01%, and the maximum elongation ε is... max =1.5%;

[0094] S2, divide the length of the support roller and the work roller and the strip width into units and define relevant parameters: divide the length of the support roller body laterally into... The length of the work roll body of each unit is divided laterally into... The unit and strip width are divided horizontally. (Increase the number of units by one if the result is even) Let N = n1 and set x i=(i-(N+1) / 2)Δx is the distance of the i-th unit from the center of the roll (the initial elongation value ε is set to 0, and this is the final result, at which point ε = 0.94%);

[0095] S3, using the Roberts formula, calculate the total rolling pressure P:

[0096]

[0097] S4, at this time, P≤P MAX Proceed to step S5;

[0098] S5 provides the influence functions of load-induced deflection changes in the work roll, intermediate roll, and support roll; the influence functions of left and right bending roll forces on the deflection changes in the work roll, intermediate roll, and support roll; and the calculation methods for intermediate parameters such as the roll-to-roll flattening coefficient between the work roll and intermediate roll, the intermediate roll and support roll, and the strip and work roll.

[0099]

[0100] S6. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i :

[0101]

[0102] S7, Calculate the elongation distribution ε in the width direction of the strip. i ;

[0103]

[0104] The elongation distribution in the width direction of the strip is obtained as follows:

[0105] S8. Calculate the roughness distribution value Ra in the width direction of the strip according to the strip roughness calculation formula. si :

[0106]

[0107] S9, set the initial value of the objective function F(X)0 = 0.004 for the selected strip, and establish the roughness control objective function F(X):

[0108]

[0109] The roughness control objective function is found to be 0.00254;

[0110] S10, the condition F(X) = 0.00254 ≤ F(X)0 = 0.004 is true. At this time, ε = 0.84%, which satisfies the condition ε = 0.84% ​​< ε in step S11. maxIf the value is 1.5%, then step S12 will output the optimal elongation rate ε = 0.84%.

[0111] Example 2

[0112] This embodiment 2 provides a process optimization method for controlling the roughness of strip steel in a leveling unit, specifically including the following steps:

[0113] S1, Collect relevant equipment and process parameters: support roller diameter D b The support roller body length is 1100mm. B The working roll diameter is 2060mm. w The length of the work roll body is 450mm. W The diameter is 2100 mm, the friction coefficient μ is 0.257, and the maximum rolling force P is... MAX The lever arm of the support roller is 15000kN. BL The lever arm of the work roll is 1500mm. WL The strip length is 1500mm, the rolling speed V is 114m / min, the deformation resistance influence coefficient k3 is 1.155, and the strip yield strength σ s The strain pressure is 149 MPa, the strain rate coefficient a is 4.4, the strip inlet thickness H is 0.653 mm, and the strip inlet thickness distribution H... i for The strip exit thickness h is 0.6475 mm, the strip width b is 1419 mm, the initial tension T1 is 48.8 kN, the post-tension T0 is 44.9 kN, the strip deformation resistance k is 168 MPa, the unit length Δx is 68 mm, the Poisson's ratio v is 0.3, the elastic modulus E is 210000 MPa, the work roll rolling mileage L is 31 km, and the original surface roughness Ra of the strip is... s0 The surface roughness Ra of the work roll is 1.7 μm. r0 The target roughness value Ra in the strip width direction is 1.284 μm. s The diameter is 1.110 μm, the increase in elongation Δε is 0.01%, and the maximum elongation ε is... max =1.5%;

[0114] S2, divide the length of the support roller and the work roller and the strip width into units and define relevant parameters: divide the length of the support roller body laterally into... The length of the work roll body of each unit is divided laterally into... The unit and strip width are divided horizontally. (If the result is even, the number of units increases by one) units, let N = n1 and set xi = (i - (N + 1) / 2)Δx as the distance of the i-th unit from the center of the roll (the initial elongation value ε is set to 0, which is the final result, at which point ε = 0.84%).

[0115] S3, using the Roberts formula, calculate the total rolling pressure P:

[0116]

[0117] S4, at this time, P≤P MAX Proceed to step S5;

[0118] S5 provides the influence functions of load-induced deflection changes in the work roll, intermediate roll, and support roll; the influence functions of left and right bending roll forces on the deflection changes in the work roll, intermediate roll, and support roll; and the calculation methods for intermediate parameters such as the roll-to-roll flattening coefficient between the work roll and intermediate roll, the intermediate roll and support roll, and the strip and work roll.

[0119]

[0120] S6. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i :

[0121]

[0122] S7, Calculate the elongation distribution ε in the width direction of the strip. i ;

[0123]

[0124] The elongation distribution in the width direction of the strip is obtained as follows:

[0125] S8. Calculate the roughness distribution value Ra in the width direction of the strip according to the strip roughness calculation formula. si :

[0126]

[0127] S9, set the initial value of the objective function F(X)0 = 0.009 for the selected strip, and establish the roughness control objective function F(X):

[0128]

[0129] The roughness control objective function is found to be 0.00803;

[0130] S10, the condition F(X) = 0.00803 ≤ F(X)0 = 0.009 is true. At this time, ε = 0.94%, which satisfies the condition ε = 0.94% < ε in step S11. max If the elongation is 1.5%, then step S12 will output the optimal elongation rate ε = 0.94%.

[0131] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A process optimization method for controlling the roughness of strip steel in a leveling unit, characterized in that, Includes the following steps: S1, collect relevant process parameters of the equipment; S2, divide the support roller, work roller body length and strip width into units and define relevant parameters; S3, calculate the total rolling pressure P; S4, if the total rolling pressure P is less than the maximum set value, i.e., P ≤ P MAX If yes, proceed to step S5; otherwise, proceed to step S12. S5 provides the calculation of intermediate parameters; S6. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i ; S7, Calculate the elongation distribution ε in the width direction of the strip. i ; S8, Calculate the roughness distribution value Ra in the width direction of the strip. si ; S9, set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control; S10. If F(X)≤F(X)0 is satisfied, proceed to step S11. Otherwise, adjust the elongation rate, let ε=ε+Δε and return to step S3. S11, if ε≤ε max If yes, proceed to step S12; otherwise, let ε = ε. max Then proceed to step S12; S12, end the calculation and output the optimal elongation ε.

2. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 1, characterized in that: The process parameters include the support roller diameter D. b Support roller body length L B Work roll diameter D w Length L of the working roll body W Friction coefficient μ, maximum rolling force P MAX The lever arm l of the support roller BL The lever arm of the work roller l WL Rolling speed V, deformation resistance influence coefficient k3, strip yield strength σ s Strain rate coefficient α, strip inlet thickness H, strip inlet thickness distribution H i Strip exit thickness h, strip width b, front tension T1, back tension T0, strip deformation resistance k, length per unit Δx, Poisson's ratio v, elastic modulus E, work roll mileage L, and original surface roughness Ra of the strip. s0 Surface roughness Ra of the working roll s0 Target roughness value Ra′ in the width direction of the strip s Increase in elongation Δε, maximum elongation ε max .

3. The process optimization method for controlling the roughness of strip steel in the leveling unit according to claim 2, characterized in that, Step S2 specifically includes: The length of the support roller is divided laterally into... The length of the working roller is divided into several units, with the roller body laterally divided into... Each unit divides the width of the strip laterally into units. Units; Let N = n1 and set x i =(i-(N+1) / 2)Δx is the distance of the i-th unit from the center of the roll, and the initial elongation value ε is set to 0.

4. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 2, characterized in that, In step S3, the total rolling pressure P is calculated using the Roberts formula: Where f represents the rolling force per unit width; l represents the contact arc length between the roll and the strip in the rolling deformation zone; a0 and a1 represent the influence coefficients of leveling steel grade and working conditions, -10.0≤a0≤10.0, -6.0≤a1≤6.0; σ P Indicates the current deformation resistance; e represents the strain rate; k1 and k2 represent the front and back tension weighting coefficients, with k1 = k2 = 0.

5.

5. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 2, characterized in that: In step S5, the intermediate parameters include the influence function of the deflection changes of the work roll, intermediate roll and support roll caused by the load, the influence function of the left and right bending roll forces on the deflection changes of the work roll, intermediate roll and support roll, and the roll-to-roll flattening coefficients of the work roll and intermediate roll, the intermediate roll and support roll, and the strip and work roll.

6. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 5, characterized in that, The intermediate parameters are calculated as follows: Among them, a ij c ij These represent the deflection influence coefficients of the i-th unit of the work roll and the support roll on the j-th unit, respectively. a wi ab i These represent the influence coefficients of the bending force and the supporting force of the i-th unit work roll, respectively. K wb K and K′ represent the inter-roll flattening coefficients of the work roll and support roll, and the strip and work roll, respectively; x=(i-(N+1) / 2)Δx、x'=(j-(N+1) / 2)Δx。 7. The process optimization method for controlling the roughness of strip steel in the leveling unit according to claim 2, characterized in that, In step S6, the strip exit thickness distribution h is calculated. i Specifically as follows: Among them, f wi f bi These represent the deflection of the working roller and the deflection of the support roller in the i-th unit, respectively. q wbj q zj These represent the inter-roll force and rolling force of the j-th unit's work roll and support roll, respectively.

8. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 2, characterized in that, In step S7, the elongation distribution ε in the width direction of the strip is calculated. i Specifically as follows: Among them, h i This indicates the thickness distribution at the strip exit.

9. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 2, characterized in that, In step S8, the roughness distribution value Ra in the width direction of the strip is calculated according to the strip roughness calculation formula. si Specifically as follows: Where, ε i This indicates the distribution of elongation along the width of the strip.

10. The process optimization method for controlling the roughness of strip steel in a leveling unit according to claim 2, characterized in that, In step S9, the objective function F(X) for strip roughness control is calculated as follows:

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