Method for controlling roughness transverse distribution uniformity of temper mill unit

Abstract

The invention discloses a method for controlling roughness transverse distribution uniformity of a temper mill. The method comprises the following steps: S1, collecting process parameters related to equipment; s2, carrying out unit division and defining related parameters; s3, giving a calculation method for intermediate parameters required by rolling pressure calculation; s4, calculating strip steel outlet thickness distribution hi; s5, the elongation distribution epsilon i of the strip steel in the width direction is calculated; s6, calculating a roughness distribution value Rasi in the width direction of the strip steel; s7, setting an initial value F (X) 0 of a target function, and calculating a strip steel roughness control target function F (X); s8, if F (X) is smaller than or equal to F (X) 0, the step S9 is executed, otherwise, the roll bending force of the working roll is adjusted, Fw is made to be equal to the sum of Fw and delta F, and the step S4 is executed again; s9, if Fw is smaller than or equal to Fwmax, the step S10 is executed, and otherwise, Fw is made to be equal to Fwmax, and then the step S10 is executed; and S10, calculation is ended, and the optimal working roll bending force Fw is output.

Description

Technical Field

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

[0002] Steel strip is widely used in construction, machinery, automotive, and electronics industries. With the advancement of mechanized production, the demand for wide, high-strength, and high-precision steel is constantly increasing, and steel strip has emerged as a product to meet these needs. With the development of materials science, stainless steel strip has also been widely used in food processing and chemical industries. Aluminum cans, milk powder cans, and chemical cans are generally made of tinplate. For tinplate, the roughness of the steel strip directly affects its surface finish and quality. Higher roughness may lead to surface defects and affect its fatigue performance, thereby reducing the fatigue life of the steel strip and ultimately affecting the appearance and quality of the product. Secondly, the roughness of the steel strip directly affects the adhesion of its surface coating. Excessive roughness may weaken the adhesion between the coating and the steel strip surface, thus reducing the performance and durability of the coating. Leveling, as the final and important process before steel strip export, has a significant impact on the control of steel strip roughness. The surface roughness of the strip after passing through the leveling unit is mainly controlled by adjusting the surface roughness of the leveling machine's work rolls. During the rolling process, the surface features of the work rolls are imprinted onto the strip surface, forming the strip roughness.

[0003] To control the surface roughness of strip steel, numerous methods have been proposed in the industry. For the roughness control of finished strip steel from a double-stand leveling mill, a method is proposed to adjust the strip roughness by controlling the rolling pressure. The influence of friction between the strip steel and the work rolls on roughness is analyzed based on rolling process parameters, and the strip roughness is ultimately optimized by setting the initial roll roughness. Considering the influence of multiple factors on strip roughness, such as roll roughness, rolling force per unit width, rolling speed, and elongation, a finishing process optimization technique to improve the surface morphology of galvanized automotive steel sheets is proposed. Other methods to improve the surface finish of strip steel include alkaline washing and brushing. However, no solution has been proposed for the uneven lateral distribution of strip roughness. Therefore, based on the process characteristics of the leveling mill and the strip roughness calculation model, a method for controlling the uniformity of the lateral roughness distribution in the leveling mill is proposed. Summary of the Invention

[0004] To address the problem of controlling the uniformity of the transverse roughness distribution of strip in existing leveling mills, a new method for controlling the uniformity of the transverse roughness distribution in leveling mills is proposed, taking into account the characteristics of the rolling process of leveling mills.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for controlling the lateral uniformity of surface roughness distribution in a leveling unit includes the following steps:

[0007] S1, collect relevant process parameters of the equipment;

[0008] S2, divide the support roller, work roller body length and strip width into units and define relevant parameters;

[0009] S3 provides the calculation method for the intermediate parameters required for rolling pressure calculation;

[0010] S4. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i ;

[0011] S5, Calculate the elongation distribution ε in the width direction of the strip. i ;

[0012] S6, Calculate the roughness distribution value Ra in the width direction of the strip. si ;

[0013] S7, set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control;

[0014] S8. If F(X) ≤ F(X) 0, proceed to step S9; otherwise, adjust the bending force of the work roll to make F... w =F w +ΔF and return to step S4;

[0015] S9, if F is satisfied w ≤F wmax If so, proceed to step S10; otherwise, let F... w =F wmax Then proceed to step S10;

[0016] S10, end the calculation and output the optimal work roll bending force F. w .

[0017] 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 Rolling pressure P, maximum bending force of the work roll F wmax The lever arm l of the support roller BL The lever arm of the work roller l WL Strip inlet thickness H, strip outlet thickness h, strip width b, strip deformation resistance k, friction coefficient μ, length of each unit Δx, Poisson's ratio v, elastic modulus E, work roll rolling kilometers L, and original surface roughness Ra of the strip. s0Surface roughness Ra of the working roll s0 The increase in bending roller force ΔF.

[0018] Preferably, step S2 specifically includes:

[0019] 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;

[0020] 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 bending force value is set to 0.

[0021] Preferably, step S3 is specifically calculated as follows:

[0022]

[0023] 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.

[0024] 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.

[0025] 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;

[0026] x=(i-(N+1) / 2)Δx, x'=(j-(N+1) / 2)Δx.

[0027] Preferably, step S4 is specifically calculated as follows:

[0028]

[0029] 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.

[0030] q wbj q zj The inter-roll force and rolling force of the j-th unit's work roll and support roll.

[0031] Preferably, step S5 is specifically calculated as follows:

[0032]

[0033] Among them, h i This indicates the thickness distribution at the strip exit.

[0034] Preferably, step S6 is specifically calculated as follows:

[0035]

[0036] Where, ε i This indicates the distribution of elongation along the width of the strip.

[0037] Preferably, step S7 is specifically calculated as follows:

[0038]

[0039] The present invention provides a method for controlling the uniformity of the transverse roughness distribution of a leveling mill. By optimizing the setting of the bending force of the work roll in the rolling process, and combining the process characteristics of the leveling mill with a strip roughness calculation model suitable for the mill, the method effectively controls the uniformity of the transverse roughness of the strip. At the same time, it avoids the large cost of modifying the on-site equipment as required by other methods, and saves the cost of controlling the transverse uniformity of the strip roughness distribution. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating the method for controlling the lateral uniformity of roughness distribution in the leveling unit according to the present invention. Detailed Implementation

[0041] 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.

[0042] Combination Figure 1 As shown, the present invention provides a method for controlling the lateral uniformity of roughness distribution in a leveling unit, comprising the following steps:

[0043] 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 Rolling pressure P, maximum bending force of the work roll F wmax The lever arm l of the support roller BL The lever arm of the work roller l WL Strip inlet thickness H, strip outlet thickness h, strip width b, strip deformation resistance k, friction coefficient μ, length of each unit Δx, Poisson's ratio v, elastic modulus E, work roll rolling kilometers L, and original surface roughness Ra of the strip. s0 Surface roughness Ra of the working rolls0 The increase in bending roller force ΔF.

[0044] S2 divides the support roller, work roller body length, and strip width into units and defines relevant parameters, specifically including:

[0045] 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... Each unit divides the width of the strip laterally into units. (Increase the number of units by one if the result is even);

[0046] 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 bending force value is set to 0.

[0047] S3 provides the calculation method for the intermediate parameters required for calculating the rolling pressure. The specific calculation is as follows:

[0048]

[0049] 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.

[0050] 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.

[0051] 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;

[0052] x=(i-(N+1) / 2)Δx, x'=(j-(N+1) / 2)Δx.

[0053] S4. 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:

[0054]

[0055] 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.

[0056] q wbj q zj The inter-roll force and rolling force of the j-th unit's work roll and support roll.

[0057] S5, calculate the elongation distribution εi in the width direction of the strip, the specific calculation is as follows:

[0058]

[0059] Among them, h i This indicates the thickness distribution at the strip exit.

[0060] S6, Calculate the roughness distribution value Ra in the width direction of the strip. si The specific calculations are as follows:

[0061]

[0062] Where, ε i This indicates the distribution of elongation along the width of the strip.

[0063] S7. Set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control. The specific calculation is as follows:

[0064]

[0065] S8. If F(X) ≤ F(X) 0, proceed to step S9; otherwise, adjust the bending force of the work roll to make F... w =F w +ΔF and return to step S4.

[0066] S9, if F is satisfied w ≤F wmax If so, proceed to step S10; otherwise, let F... w =F wmax Then proceed to step S10.

[0067] S10, end the calculation and output the optimal work roll bending force F. w .

[0068] Example 1

[0069] This embodiment 1 provides a method for controlling the lateral uniformity of roughness distribution in a leveling unit, specifically including the following steps:

[0070] 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 2100mm, the rolling pressure P is 3454kN, and the maximum bending force F of the work roll is... wmax The lever arm of the support roller is 800kN. BLThe lever arm of the work roll is 1500mm. WL The strip thickness is 1500mm, the entry thickness H is 1.008mm, the exit thickness h is 1mm, the strip width b is 1238mm, the strip deformation resistance k is 168MPa, the coefficient of friction μ is 0.254, the length of each unit Δx is 68mm, the Poisson's ratio v is 0.3, the elastic modulus E is 210000MPa, the working roll mileage L is 10km, and the original surface roughness Ra of the strip is... s0 The original surface roughness Ra of the working roll is 1.85 μm. r0 The thickness is 1.3 μm, and the increase in bending roller force ΔF is 10 kN;

[0071] S2 divides 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, and the initial bending force value is set to 0;

[0072] S3 provides the calculation method for the intermediate parameters required for calculating rolling pressure:

[0073]

[0074]

[0075] S4. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i :

[0076] The thickness distribution of the strip at the exit is as follows:

[0077] [0.99889,0.99921,0.99953,0.99983,1.00011,1.00035,1.00055,1.00069,1.00078,1.000 81, 1.00078, 1.000069, 1.00055, 1.00035, mm; 1.00011, 0.99983, 0.99953, 0.99921, 0.99889]

[0078] S5, Calculate the strip width direction elongation distribution εi:

[0079]

[0080] The elongation distribution in the width direction of the strip is obtained as follows:

[0081]

[0082] S6. Calculate the roughness distribution value Ra in the width direction of the strip according to the strip roughness calculation formula. si :

[0083] The roughness distribution along the width of the strip is as follows:

[0084]

[0085] S7, set the initial value of the objective function F(X)0 = 0.004, and establish the roughness control objective function F(X):

[0086] The roughness control objective function is determined to be 0.006;

[0087] S8, the condition F(X)=0.006≤F(X)0=0.004 is not met. Adjust the bending force of the work roll, let F w =F w +ΔF and return to step S4.

[0088] S9, Judgment condition F w =100kN≤F wmax =800kN is established, proceed to step S10.

[0089] S10, end the calculation and output the optimal working roll bending force as 100kN.

[0090] Example 2

[0091] This embodiment 2 provides a method for controlling the lateral uniformity of roughness distribution in a leveling unit, which specifically includes the following steps:

[0092] 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 2100mm, the rolling pressure P is 787.7kN, and the maximum bending force F of the work roll is... wmax The lever arm of the support roller is 800kN. BL The lever arm of the work roll is 1500mm. WLThe strip thickness is 1500mm, the entry thickness H is 1.605mm, the exit thickness h is 1.6mm, the strip width b is 1238mm, the strip deformation resistance k is 1076MPa, the coefficient of friction μ is 0.256, the length of each unit Δx is 68mm, the Poisson's ratio v is 0.3, the elastic modulus E is 210000MPa, the working roll mileage L is 12km, and the original surface roughness Ra of the strip is... s0 The original surface roughness Ra of the work roll is 2.15 μm. r0 The thickness is 1.3 μm, and the increase in bending roller force ΔF is 10 kN;

[0093] S2 divides 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, and set the initial bending force value to 0;

[0094] S3 provides the calculation method for the intermediate parameters required for calculating rolling pressure:

[0095]

[0096]

[0097] S4, Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution hi:

[0098] The thickness distribution of the strip at the exit is as follows:

[0099] [1.59570,1.59663,1.59751,1.59830,1.59900,1.59958,1.60004,1.60037,1.60057,1.600 64, 1.60057, 1.60037, 1.60004, 1.59958, mm; 1.59900, 1.59830, 1.59751, 1.59663, 1.59570]

[0100] S5, Calculate the strip width direction elongation distribution εi:

[0101]

[0102] The elongation distribution in the width direction of the strip is obtained as follows:

[0103]

[0104] S6, Calculate the roughness distribution value Rasi in the width direction of the strip according to the strip roughness calculation formula:

[0105]

[0106] The roughness distribution along the width of the strip is as follows:

[0107]

[0108] S7, set the initial value of the objective function F(X)0 = 0.004, and establish the roughness control objective function F(X):

[0109]

[0110] The roughness control objective function is thus determined to be 0.022;

[0111] S8, the condition F(X)=0.022≤F(X)0=0.004 is not met. Adjust the bending force of the work roll, let F w =F w +ΔF and return to step S4.

[0112] S9, Judgment condition F w =750kN≤F wmax =800kN is established, proceed to step S10.

[0113] S10, end the calculation and output the optimal working roll bending force as 750kN.

[0114] 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 method for controlling the lateral uniformity of surface roughness distribution 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 provides the calculation method for the intermediate parameters required for rolling pressure calculation; S4. Establish the elastic deformation model of the roll system and the strip exit thickness model, and calculate the strip exit thickness distribution h. i ; S5, Calculate the elongation distribution ε in the width direction of the strip. i ; S6, Calculate the roughness distribution value Ra in the width direction of the strip. si ; S7, set the initial value of the objective function F(X)0, and calculate the objective function F(X) for strip roughness control; S8. If F(X) ≤ F(X) 0, proceed to step S9; otherwise, adjust the bending force of the work roll to make F... w =F w +ΔF and return to step S4; S9, if F is satisfied w ≤F wmax If so, proceed to step S10; otherwise, let F... w =F wmax Then proceed to step S10; S10, end the calculation and output the optimal work roll bending force F. w .

2. The method for controlling the lateral distribution uniformity of roughness 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 Rolling pressure P, maximum bending force of the work roll F wmax The lever arm l of the support roller BL The lever arm of the work roller l WL Strip inlet thickness H, strip outlet thickness h, strip width b, strip deformation resistance k, friction coefficient μ, length of each unit Δx, Poisson's ratio v, elastic modulus E, work roll rolling kilometers L, and original surface roughness Ra of the strip. s0 Surface roughness Ra of the working roll s0 The increase in bending roller force ΔF.

3. The method for controlling the lateral uniformity of roughness distribution in a 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. Unit; 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, and set the initial bending force value to 0.

4. The method for controlling the lateral distribution uniformity of roughness in a leveling unit according to claim 2, characterized in that, The specific calculation for step S3 is 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 a bi 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。 5. The method for controlling the lateral distribution uniformity of roughness in a leveling unit according to claim 2, characterized in that, The specific calculation for step S4 is 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 The inter-roll force and rolling force of the j-th unit's work roll and support roll.

6. The method for controlling the lateral uniformity of roughness distribution in a leveling unit according to claim 2, characterized in that, The specific calculation for step S5 is as follows: Among them, h i This indicates the thickness distribution at the strip exit.

7. The method for controlling the lateral distribution uniformity of roughness in a leveling unit according to claim 2, characterized in that, The specific calculation for step S6 is as follows: Where, ε i This indicates the distribution of elongation along the width of the strip.

8. The method for controlling the lateral distribution uniformity of roughness in a leveling unit according to claim 2, characterized in that, The specific calculation for step S7 is as follows:

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