Method for calculating equivalent rolling kilometers of rollers of twenty-high rolling mill

Abstract

The invention discloses a method for calculating equivalent rolling kilometers of rollers of a twenty-high rolling mill, which comprises the following steps of: collecting current roller characteristic parameters and allowable range, selecting target process characteristic parameters and calculated inter-roller pressure, rolling pressure and roller limit equivalent rolling kilometers; and collecting actual process parameters and the calculated inter-roller pressure and rolling pressure, calculating equivalent rolling kilometers of the rollers, judging whether a roller replacement judgment index sigma is established or not, judging the roller replacement judgment index, and recording the state of the rollers for next health evaluation. According to the full-period roller health degree evaluation system, a new thought and method are provided for roller wear management and replacement decision making by introducing an equivalent rolling kilometer prediction method and comprehensive evaluation of the actual wear loss of the roller. Establishment of the system not only helps to improve efficiency and quality of rolling production and reduce production cost and energy consumption, but also provides a new technical approach and theoretical support for intelligent and fine management of the rolling technology.

Description

Technical Field

[0001] The invention belongs to the technical field of cold rolling, and in particular relates to a method for calculating the equivalent rolling kilometres of a twenty-high rolling mill roll. Background Art

[0002] In the metal rolling industry, rolling mills, as high-precision cold rolling equipment, place extremely high demands on roll wear and fatigue management. Rollers are critical components in the rolling process, and their radius wear directly impacts the dimensional accuracy and surface quality of rolled products. Traditionally, roll replacement decisions have been based primarily on absolute rolling mileage or simple wear measurements. This approach ignores the impact of varying rolling conditions on roll wear rates, making it difficult to ensure optimal roll operation, thus impacting rolling efficiency and product quality.

[0003] With the continuous advancement of rolling technology and the increasing demand for intelligent management, researchers have begun exploring more accurate and comprehensive methods for assessing roll wear. However, existing methods for predicting equivalent rolling kilometers (EKKs) mostly focus on theoretical models and lack close integration with the actual rolling process, resulting in significant deviations between predicted results and actual wear. This invention introduces EKKs as an innovative evaluation metric. By considering the equivalent wear and fatigue under actual and target rolling process parameters, it provides a new perspective for roll wear assessment.

[0004] Furthermore, roll health evaluation is an integral part of the rolling process, directly impacting roll life and the stability of rolled products. However, existing health evaluation systems are mostly based on a single wear metric, overlooking the comprehensive performance changes of the rolls at different rolling stages and conditions. Therefore, establishing a comprehensive and scientific roll health evaluation system is crucial for improving rolling efficiency and reducing production costs. Summary of the Invention

[0005] In order to solve the above problems, the technical solution adopted by the present invention is: a method for calculating the equivalent rolling kilometers of a twenty-high rolling mill roll, comprising the following steps:

[0006] S1: Obtain the current roll characteristic parameters of the rolling mill, the current fatigue layer residual amount and the allowable range of each roll diameter;

[0007] S2: Obtain target process parameter C0 of the rolling mill;

[0008] S3: Obtain the inter-roll pressure and rolling pressure distribution of the actual process parameters C1 in advance when the strip is produced, and the limit equivalent rolling kilometer L eqmax ;

[0009] S4: Based on the current roll characteristic parameters, the rolling mill target process parameters C0, the inter-roller pressure and the rolling pressure distribution, under the actual rolling mill process parameters C1, calculate the roll equivalent rolling kilometers L eq ;

[0010] S5: Judgment If the result is yes, go to step S6; if the result is no, there is no need to change the roller, go to step S7;

[0011] S6: Replace the rolls, determine the grinding amount based on the roll design requirements and the fatigue layer depth distribution T1(y), and grind the rolls;

[0012] S7: Judgment Is it established? If the judgment result is yes, the roller is scrapped. If the judgment result is no, continue; D temp This is the diameter of the roller, D min The minimum diameter of the roller to allow operation, D max is the maximum diameter of the roller;

[0013] S8: Record the current state of the roll, including the roll diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, for the next health status evaluation.

[0014] Furthermore, the calculation of the roll equivalent rolling kilometers based on the current roll characteristic parameters, the target process parameters of the rolling mill, the inter-roller pressure and the rolling pressure distribution under the actual process parameters of the rolling mill is carried out in the following specific steps:

[0015] S41: Calculating the wear curve distribution W1(y) generated by the current roller operation when the actual process parameters are calculated;

[0016] S42: Calculating the fatigue layer distribution T1(y) of the roller generated during the current roller operation when the actual process parameters are used;

[0017] S43: performing weighted sum F1 on the fatigue layer distribution and the wear amount distribution W1(y);

[0018] S44: Iteration initial value L, iteration step length ΔL, iteration variable k=0; under target process parameter C0, equivalent rolling kilometers L eq =L+k*ΔL, the fatigue layer distribution T1(y) and wear distribution W0(y) of the roller calculated in steps S41 to S43 are then weighted, F0=0.63∑T1(y)+0.37∑W1(y), and k is gradually increased iteratively until |F1-F0|<1, and the equivalent rolling kilometers L of the roller are calculated. eq .

[0019] Furthermore, the process of calculating the wear curve distribution of the roller during the actual process parameters is as follows: The process of calculating the wear curve distribution of the roller during the actual process parameters is as follows:

[0020] The wear includes the wear between the rolls and the wear between the work rolls and the workpiece;

[0021] Calculate the wear between the rollers and the wear between the rollers and the workpiece in sections;

[0022] Divide the wear of each roller into several parts;

[0023] Then, according to the lateral distribution of the inter-roller pressure and the rolling pressure, the wear amount of each area is calculated segment by segment; finally, the wear distribution curve of the roll is drawn.

[0024] Furthermore, the formula used for the inter-roller wear between the rollers is as follows:

[0025]

[0026] Where: y is the transverse coordinate of the roll and strip unit; Q ro (y) is the rolling L t The wear of the rollers when the length of the strip is greater than that of the strip; q(y) is the distribution of the contact pressure between the rollers; D is the roller diameter; R 10 ,R 20 is the working radius of the two contacting rollers; R1(y), R2(y) are the load radius distribution values of the two rollers.

[0027] Furthermore, the calculation formula for the wear between the working roll and the rolled piece is as follows:

[0028]

[0029] Where y is the transverse coordinate of the roll and strip unit; Q rp (y) is the rolling L t The wear of the working roll when the length of the strip is 1000 mm; q′(y) is the distribution of rolling pressure; D s is the diameter of the working roll; C(y) is a function related to the lateral flow of metal in the roll gap; h c is the average thickness of the strip deformation zone.

[0030] Furthermore, the depth of the roller fatigue layer is obtained from the rolling kilometers, the corresponding process parameters and the pressure distribution between the rollers:

[0031]

[0032] Where N is the number of stress cycles; a is the crack depth; E is the elastic modulus of the roller surface material; ε fis the fracture ductility; ΔK is the stress intensity factor range Δσ is the amplitude of cyclic stress change in MPa; ΔK th =(8.5-0.0003σ 0.2 )(1-R) γ ; σ 0.2 is the yield limit of the roll surface material; γ is the material determination constant; a0 and a1 are the initial crack depth of the roll and the crack depth at which the roll needs to be replaced and repaired, respectively.

[0033] Furthermore, the weighted sum F1 of the fatigue crack distribution curve T1(y) and the wear distribution curve W1(y) of the rolling mill is as follows:

[0034] F1=0.63∑T1(y)+0.37∑W1(y).

[0035] A device for evaluating the health of a roller during its entire service life, comprising:

[0036] Acquisition module 1: used to obtain the current roll characteristic parameters of the rolling mill, the current fatigue layer residual amount and the allowable range of each roll diameter;

[0037] Acquisition module II: used to obtain the target process parameter C0 of the rolling mill;

[0038] Calculation module I: used to obtain the inter-roll pressure and rolling pressure distribution of the actual process parameters C1 in advance during strip production, and the limit equivalent rolling kilometers L eqmax ;

[0039] Calculation module II: used to calculate the roll equivalent rolling kilometers L based on the current roll characteristic parameters, rolling mill target process parameters C0, roll pressure and rolling pressure distribution, under the actual rolling mill process parameters C1 eq ;

[0040] Judgment module I: used to judge Is it established? If the judgment result is yes, then go to the grinding module. If the judgment result is no, then there is no need to change the roller, and go to the judgment module II;

[0041] Grinding module: used to replace the rolls, determine the grinding amount according to the roll design requirements and the fatigue layer depth distribution T1(y), and perform roller grinding;

[0042] Judgment Module II: used to judge Is it established? If the judgment result is yes, the roller is scrapped. If the judgment result is no, continue; D temp This is the diameter of the roller, D min D is the minimum diameter of the roller to allow operation. max is the maximum diameter of the roller;

[0043] Recording module: used to record the current status of the roller, including the roller diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, which is used for the next health status evaluation.

[0044] A computer device comprises: a processor and a memory, wherein the memory stores a program module, and wherein the program module runs on the processor to implement any one of the methods described above.

[0045] The present invention provides a method for calculating the equivalent rolling kilometers of a twenty-high mill roll. The method can effectively evaluate the health of the rolls of the mill throughout the entire cycle and has the following advantages:

[0046] The present full-cycle roll health evaluation system, by integrating a method for predicting equivalent rolling mileage and a comprehensive assessment of actual roll wear, provides new insights and methods for roll wear management and replacement decisions. This system not only helps improve the efficiency and quality of rolling production, while reducing production costs and energy consumption, but also provides new technical approaches and theoretical support for the intelligent and refined management of rolling technology.

[0047] This application proposes a method for calculating equivalent rolling kilometers and, combined with the permissible range of roll diameter, constructs a lifecycle roll health evaluation system. This system comprehensively assesses the health of a roll throughout its entire lifecycle, from new rolls to scrap, accurately reflecting its usage and remaining lifespan. This provides a scientific basis for full-cycle health analysis of rolling mills and lifecycle health management techniques for rolls.

[0048] The specific operation of roll health evaluation is: collect the current roll characteristic parameters and allowable range, select the target process characteristic parameters and the calculated roll gap pressure, rolling pressure, roll limit equivalent rolling kilometers, then collect the actual process parameters and the calculated roll gap pressure, rolling pressure, calculate the roll equivalent rolling kilometers, and judge HD D ≤0.1 is established, if the judgment result is yes, the roller is scrapped, if the judgment result is no, then judge HD L ≤0.2 is established. If the judgment result is yes, the roll is replaced and the roll is ground. If the judgment result is no, the roll does not need to be replaced and the roll status is recorded for the next health evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0050] Figure 1 This is a calculation block diagram for evaluating the health of the rolls of the rolling mill in the entire cycle of the present invention;

[0051] Figure 2 It is a schematic diagram of the segmented calculation of the axial wear and fatigue of the rolling mill rolls in the present invention. DETAILED DESCRIPTION

[0052] It should be noted that, unless there is any conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] Figure 1 This is a calculation block diagram for evaluating the health of the rolls of the rolling mill in the entire cycle of the present invention;

[0055] A method for calculating the equivalent rolling kilometers of a twenty-high rolling mill roll comprises the following steps:

[0056] S1: Obtain the current roll characteristic parameters of the rolling mill, the current fatigue layer residual amount and the allowable range of each roll diameter;

[0057] S2: Obtain target process parameter C0 of the rolling mill;

[0058] S3: Obtain the inter-roll pressure and rolling pressure distribution of the actual process parameters C1 in advance when the strip is produced, and the limit equivalent rolling kilometer L eqmax ;

[0059] S4: Based on the current roll characteristic parameters, the rolling mill target process parameters C0, the inter-roller pressure and the rolling pressure distribution, under the actual rolling mill process parameters C1, calculate the roll equivalent rolling kilometers Leq ;

[0060] S5: Judgment If the result is yes, go to step S6; if the result is no, there is no need to change the roller, go to step S7;

[0061] S6: Replace the rolls, determine the grinding amount based on the roll design requirements and the fatigue layer depth distribution T1(y), and grind the rolls;

[0062] S7: Judgment Is it established? If the judgment result is yes, the roller is scrapped. If the judgment result is no, continue; D temp This is the diameter of the roller, D min D is the minimum diameter of the roller to allow operation. max is the maximum diameter of the roller;

[0063] S8: Record the current state of the roll, including the roll diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, for the next health status evaluation.

[0064] Steps S1 / S2 / S3 are performed in parallel, and steps S4 / S5 / S6 / S7 / S8 are performed sequentially;

[0065] Furthermore, the current roll characteristic parameters of the rolling mill mainly include: the current diameter of each roll in the roll system (including the working roll, the first intermediate roll, the second intermediate roll, and the backup roll);

[0066] The target process parameters C0 mainly include: the front and rear tensions of the strip T0, T1, t; the inlet and outlet thicknesses of the strip h0, h1, mm; the strip width B, mm; the yield strength of the strip K, mPa; the total rolling pressure P, t; the elastic modulus E, gPa; and the Poisson's ratio v. That is, C0 = {T0, T1, h0, h1, B, K, P, E, v}.

[0067] The actual process parameters C1 used in strip production mainly include: the front and rear tensions of the strip T0, T1, t; the inlet and outlet thicknesses of the strip h0, h1, mm; the strip width B, mm; the yield strength of the strip K, mPa; the total rolling pressure P, t; the elastic modulus E, gPa; the Poisson's ratio v; that is, C1 = {T0, T1, h0, h1, B, K, P, E, v} and the actual rolling kilometer L1, km;

[0068] Furthermore, the equivalent rolling mileage of the roller, i.e., the roller surface wear fatigue generated by the actual process parameters of the roller, is converted to the rolling mileage of the target process parameters, specifically in the following steps:

[0069] S41: calculating the wear curve distribution of the roller during the current operation when the actual process parameters are calculated;

[0070] S42: Calculating the fatigue layer distribution of the roller generated during the current roller operation when the actual process parameters are used;

[0071] S43: performing weighted sum F1 on the fatigue layer distribution curve and the wear amount distribution curve;

[0072] S44: Iteration initial value L, iteration step length ΔL, iteration variable k=0; under target process parameter C0, equivalent rolling kilometers L eq = L + k * ΔL, the roll fatigue crack distribution and wear distribution W0(y) calculated in steps S41 to S43 are then weighted to calculate F0 = 0.63∑T1(y) + 0.37∑W1(y). k is iteratively increased until |F1-F0| < 1. Leq is continuously iterated until F1-F0 < 1. At this point, Leq is the equivalent rolling kilometers. Its physical meaning is that the target process parameter C0 is the rolling kilometers Leq; the actual process parameter C1 is the rolling kilometers L1; the resulting roll losses are equivalent.

[0073] Furthermore, the process of calculating the wear curve distribution of the roller during the actual process parameters is as follows: The process of calculating the wear curve distribution of the roller during the actual process parameters is as follows:

[0074] The wear includes the wear between the rolls and the wear between the rolls and the workpiece;

[0075] Calculate the wear between the rollers and the wear between the rollers and the workpiece in sections;

[0076] according to Figure 2 , the wear of each roller is divided into several parts; the wear can be divided into three parts: the part in contact with the workpiece, the part in contact with an intermediate roller, and the part without contact;

[0077] Then, according to the lateral distribution of the inter-roller pressure and the rolling pressure, the wear amount of each area is calculated segment by segment; finally, the wear amount distribution W1(y) of the roll is drawn.

[0078] The formula used for the inter-roller wear between the rolls is as follows:

[0079]

[0080] Where: y is the transverse coordinate of the roller and strip unit; Q ro (y) is the rolling L t The wear of the rollers when the length of the strip is less than 100 mm; q(y) is the distribution of the contact pressure between the rollers, kN / mm; D is the roller diameter, mm; R 10 ,R20 is the working radius of the two contacting rollers, mm; R1(y), R2(y) are the load radius distribution values of the two rollers, mm.

[0081] The calculation formula used for the wear between the working roll and the rolled product is as follows:

[0082]

[0083] Where y is the transverse coordinate of the roll and strip unit; Q rp (y) is the rolling L t The wear of the working roll when the length of the strip is 1000 mm; q′(y) is the distribution of rolling pressure, kN / mm; D s is the working roll diameter, mm; C(y) is a function related to the lateral flow of metal in the roll gap; h c is the average thickness of the strip deformation zone;

[0084] The roller fatigue layer depth is calculated from the rolling kilometers, the corresponding process parameters and the pressure distribution between the rollers:

[0085]

[0086] Where N is the number of stress cycles; a is the crack depth, mm; E is the elastic modulus of the roller surface material, gPa; ε f is the fracture ductility; ΔK is the stress intensity factor range Δσ is the amplitude of cyclic stress change, mpa; ΔK th =(8.5-0.0003σ 0.2 )(1-R) γ ; σ 0.2 is the yield strength of the roll surface material, mPa; γ is the material determination constant; a0 and a1 are the depth of the roll initial crack and the depth of the crack that requires the roll to be replaced and repaired, respectively, in mm;

[0087] The process of weighted sum F1 of the fatigue crack distribution curve T1(y) and the wear distribution curve W1(y) of the roller is as follows:

[0088] F1=0.63∑T1(y)+0.37∑W1(y).

[0089] Example 1

[0090] like Figure 1 As shown, the present invention provides a full-cycle roll health evaluation method for a rolling mill, and the implementation steps are as follows.

[0091] (1) In step (A), before a coil of steel strip is produced, the current roll characteristic parameters and the allowable range of the rolling mill are collected. These parameters mainly include: the current diameter of each roll in the rolling system (including the work roll, the first intermediate roll, the second intermediate roll, and the backup roll), the residual amount of fatigue layer, and the allowable range of the roll diameter of each roll.

[0092] D S =60mm,D P =138mm,D JK =235mm,D CD =406.4mm, here we take the working roll as an example, the applicable range of the working roll diameter is D S ∈[58mm,73.5mm]. Initial state a0=0 (new roller).

[0093] (2) In step (B), the target process parameter C0 is selected, the inter-roll pressure and rolling pressure distribution are calculated in advance, and the limit equivalent rolling kilometer L calculated by this method is calculated. eqmax The main parameters include: front and rear tension T0 = 20t, T1 = 3.5t; strip inlet and outlet thickness h0 = 2.30mm, h1 = 1.49mm; strip width B = 1030mm; strip yield limit K = 669.62mpa; total rolling pressure P = 496.58t; elastic modulus E = 200gpa; Poisson's ratio v = 0.27; L eqmax =6.0km;

[0094] (3) In step (C), the actual process parameters C1 used in strip production and the pre-calculated inter-roller pressure and rolling pressure distribution, and the limit equivalent rolling kilometer L are obtained. eqmax The main parameters include: strip front and rear tension T0 = 20t, T1 = 3.5t; strip inlet and outlet thickness h0 = 2.30mm, h1 = 1.38mm; strip width B = 1025mm; strip yield limit K = 1037.95mpa; total rolling pressure P = 448.98t; elastic modulus E = 200gpa; Poisson's ratio v = 0.27; actual rolling mileage L1 = 3.64km;

[0095] (4) In step (D), based on the current roll characteristic parameters, the rolling mill target process parameters C0, the inter-roller pressure and the rolling pressure distribution, under the actual rolling mill process parameters C1, the roll equivalent rolling kilometers L is calculated. eq Calculate L according to the steps in step (D) eq =4.52km

[0096] (5) In step (E), determine If the judgment result is not established, it means that there is no need to change the roll at present, and the process goes to step (F), and the roll replacement judgment index σ is set to 0.2;

[0097] (6) Step (F) The rolls are replaced, and the grinding amount is determined according to the roll design requirements and the fatigue layer depth distribution T1(y), and the rolls are ground;

[0098] (7) In step (G), determine If the judgment result is not established, the process goes to step (F) to determine whether to replace the roll. The roll scrap judgment index m is set to 0.1;

[0099] (8) In step (H), the current state of the roll is recorded, including the roll diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, which is used for the next health status evaluation.

[0100] Example 2

[0101] like Figure 1 As shown, the present invention provides a full-cycle roll health evaluation method for a rolling mill, and the implementation steps are as follows.

[0102] (1) In step (A), the current roll characteristic parameters and allowable range of the rolling mill are collected before a roll of strip steel is produced. These parameters mainly include: the current diameter of each roll in the rolling system (including the working roll, the first intermediate roll, the second intermediate roll, and the backup roll), the residual amount of the fatigue layer, and the allowable range of the roll diameter of each roll. S =65mm,D P =138mm,D JK =235mm,D CD =406.4mm, here we take the working roll as an example, the applicable range of the working roll diameter is D S ∈[58mm,73.5mm]. Initial state a0=0 (new roller).

[0103] (2) In step (B), the target process parameter C0 is selected, the inter-roll pressure and rolling pressure distribution are calculated in advance, and the limit equivalent rolling kilometer L calculated by this method is calculated. eqmax The main parameters include: front and rear tension T0 = 20t, T1 = 3.5t; strip inlet and outlet thickness h0 = 2.20mm, h1 = 1.34mm; strip width B = 1200mm; strip yield limit K = 823mpa; total rolling pressure P = 517t; elastic modulus E = 195gpa; Poisson's ratio v = 0.28; L eqmax =6.0km

[0104] (3) In step (C), the actual process parameters C1 used in strip production and the pre-calculated inter-roller pressure and rolling pressure distribution are obtained. These parameters mainly include: the front and rear tensions of the strip T0 = 20t, T1 = 3.5t; the inlet and outlet thicknesses of the strip h0 = 2.20mm, h1 = 1.37mm; the strip width B = 1110mm; the yield strength of the strip K = 702.48mpa; the total rolling pressure P = 517.46t; the elastic modulus E = 186gpa; the Poisson's ratio v = 0.28; and the actual rolling mileage L1 = 4.43km.

[0105] (4) In step (D), based on the current roll characteristic parameters, the rolling mill target process parameters C0, the inter-roller pressure and the rolling pressure distribution, under the actual rolling mill process parameters C1, the roll equivalent rolling kilometers L is calculated. eq Calculate L according to the steps in step (D) eq =4.95km

[0106] (5) In step (E), determine If the result is true, it means that the roll needs to be replaced, and the process goes to step (F); the roll replacement judgment index σ is 0.2;

[0107] (6) Step (F) The rolls are replaced, and the grinding amount is determined according to the roll design requirements and the fatigue layer depth distribution T1(y), and the rolls are ground;

[0108] (7) In step (G), determine If the judgment result is not established, the process goes to step (F) to determine whether to replace the roll. The roll scrap judgment index m is set to 0.1;

[0109] (8) In step (H), the current state of the roll is recorded, including the roll diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, and is used for the next health status evaluation.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the health of a twenty-high mill roll during its entire service life, characterized by: The following steps are involved: S1: Obtain the current roll characteristic parameters of the rolling mill, the current fatigue layer residual amount and the allowable range of each roll diameter; S2: Obtain target process parameter C0 of the rolling mill; S3: Obtain the inter-roll pressure and rolling pressure distribution of the actual process parameters C1 in advance when the strip is produced, and the limit equivalent rolling kilometer L eqmax ; S4: Based on the current roll characteristic parameters, the rolling mill target process parameters C0, the inter-roller pressure and the rolling pressure distribution, under the actual rolling mill process parameters C1, calculate the roll equivalent rolling kilometers L eq ; S5: Judgment ≤Whether the roll replacement judgment index σ is established. If the judgment result is yes, the process proceeds to step S6. If the judgment result is no, the roll does not need to be replaced and the process proceeds to step S7. S6: Replace the rolls, determine the grinding amount based on the roll design requirements and the fatigue layer depth distribution T1(y), and grind the rolls; S7: Judgment ≤Whether the roll scrap judgment index m is established. If the judgment result is yes, the roll is scrapped. If the judgment result is no, continue; D temp This is the diameter of the roller, D min D is the minimum diameter of the roller to allow operation. max is the maximum diameter of the roller; S8: Record the current state of the roll, including the roll diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, for the next health status evaluation.

2. The method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 1 is characterized in that: The specific steps of calculating the equivalent rolling kilometers of the rolls based on the current roll characteristic parameters, the target process parameters of the rolling mill, the pressure between the rolls and the rolling pressure distribution under the actual process parameters of the rolling mill are as follows: S41: Calculating the wear curve distribution W1(y) generated by the current roller operation when the actual process parameters are calculated; S42: Calculating the fatigue layer distribution T1(y) of the roller generated during the current roller operation when the actual process parameters are used; S43: performing weighted sum F1 on the fatigue layer distribution and the wear amount distribution W1(y); S44: Iteration initial value L, iteration step length ΔL, iteration variable k=0; under target process parameter C0, equivalent rolling kilometers L eq =L+k*ΔL, the fatigue layer distribution T1(y) and wear distribution W0(y) of the roller calculated in steps S41 to S43 are then weighted, F0=0.63∑T1(y)+0.37∑W1(y), and k is gradually increased iteratively until |F1-F0|<1, and the equivalent rolling kilometers L of the roller are calculated. eq .

3. The method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 2, wherein: The process of calculating the wear curve distribution of the roller during the actual process parameters is as follows: The wear includes the wear between the rolls and the wear between the work rolls and the workpiece; Calculate the wear between the rollers and the wear between the rollers and the workpiece in sections; Divide the wear of each roller into several parts; Then, according to the lateral distribution of the inter-roller pressure and the rolling pressure, the wear amount of each area is calculated segment by segment; finally, the wear distribution curve of the roll is drawn.

4. A method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 3, characterized in that: The formula used for the inter-roller wear between the rolls is as follows: Where: y is the transverse coordinate of the roller and strip unit; Q ro (y) is the rolling L t The wear of the rollers when the length of the strip is greater than that of the strip; q(y) is the distribution of the contact pressure between the rollers; D is the roller diameter; R 10 ,R 20 is the working radius of the two contacting rollers; R1(y), R2(y) are the load radius distribution values of the two rollers.

5. The method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 3, wherein: The calculation formula used for the wear between the working roll and the rolled product is as follows: Where y is the transverse coordinate of the roll and strip unit; Q rp (y) is the rolling L t The wear of the working roll when the length of the strip is 1000 mm; q′(y) is the distribution of rolling pressure; D s is the diameter of the working roll; C(y) is a function related to the lateral flow of metal in the roll gap; h c is the average thickness of the strip deformation zone.

6. A method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 2, characterized in that: The roller fatigue layer depth is calculated from the rolling kilometers, the corresponding process parameters and the pressure distribution between the rollers: Where N is the number of stress cycles; a is the crack depth; E is the elastic modulus of the roller surface material; ε f is the fracture ductility; ΔK is the stress intensity factor range Δσ is the amplitude of cyclic stress change in MPa; ΔK th =(8.5-0.0003σ 0.2 )(1-R) γ ; σ 0.2 is the yield limit of the roll surface material; γ is the material determination constant; a0 and a1 are the initial crack depth of the roll and the crack depth at which the roll needs to be replaced and repaired, respectively.

7. The method for calculating the equivalent rolling kilometers of a twenty-high mill roll according to claim 3 is characterized in that: The process of weighted sum F1 of the fatigue crack distribution curve T1(y) and the wear distribution curve W1(y) of the roller is as follows: F1=0.63∑T1(y)+0.37∑W1(y).

8. A twenty-high mill roll health evaluation device for the entire service life, characterized by: include: Acquisition module 1: used to obtain the current roll characteristic parameters of the rolling mill, the current fatigue layer residual amount and the allowable range of each roll diameter; Acquisition module II: used to obtain the target process parameter C0 of the rolling mill; Calculation module I: used to obtain the inter-roll pressure and rolling pressure distribution of the actual process parameters C1 in advance during strip production, and the limit equivalent rolling kilometers L eqmax ; Calculation module II: used to calculate the roll equivalent rolling kilometers L based on the current roll characteristic parameters, rolling mill target process parameters C0, roll pressure and rolling pressure distribution, under the actual rolling mill process parameters C1 eq ; Judgment module I: used to judge ≤Whether the roll replacement judgment index σ is established. If the judgment result is yes, the process proceeds to the grinding module. If the judgment result is no, the roll does not need to be replaced and the process proceeds to the judgment module II; Grinding module: used to replace the rolls, determine the grinding amount according to the roll design requirements and the fatigue layer depth distribution T1(y), and perform roller grinding; Judgment Module II: used to judge ≤Whether the roll scrap judgment index m is established. If the judgment result is yes, the roll is scrapped. If the judgment result is no, continue; D temp This is the diameter of the roller, D min The minimum diameter of the roller to allow operation, D max is the maximum diameter of the roller; Recording module: used to record the current status of the roller, including the roller diameter and the initial fatigue layer depth a0. The value of a0 is the fatigue layer depth T1(y) minus the grinding amount, which is used for the next health status evaluation.

9. A computer device comprising: A processor and a memory, wherein the memory stores a program module, wherein the program module runs on the processor to implement the method according to any one of claims 1 to 7.

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