A method for designing the roll diameter and roll system configuration of an eighteen-roll cold rolling mill for stainless steel

Abstract

The present application belongs to the field of metallurgical equipment and rolling process, and particularly relates to a kind of eighteen roll mill roll diameter design and roll train configuration method for stainless steel cold rolling.In the aspect of roll diameter design, the minimum rollable thickness formula is used to determine the appropriate work roll diameter, the intermediate roll, support roll, side support roll and backing roll diameters are calculated through the empirical formula of eighteen roll mill roll diameter, and the material mechanics formula and Hertz formula are used to complete the roll checking.In the aspect of roll train configuration, the work roll, intermediate roll and support roll are configured according to the arrangement form of ordinary six-roll mill, and the applicable range of support roll and backing roll is given by using geometric relationship and geometric constraint.The reasonable roll diameter design and roll train configuration of the present application can reduce the deformation stress of rolled piece, reduce surface defects, improve the surface finish and dimensional accuracy of rolled piece, reduce rolling deformation and rolling pressure, effectively prevent equipment vibration and impact, and thus improve the running stability of roll train.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical equipment and rolling processes, and particularly relates to a method for designing the roll diameter and configuring the roll system of an 18-roll mill for cold rolling of stainless steel. Background Technology

[0002] In recent years, with the increasing demand and requirements of the steel market and downstream users for metal sheet and strip production, further improvement of the strength, thickness, precision, and other product quality of stainless steel cold-rolled sheet and strip has become key to product transformation and upgrading. However, since traditional four- and six-roll mills can no longer meet the high-precision production requirements of sheet and strip, considering that multi-roll mills can achieve thinner sheet and strip production by utilizing multi-pass rolling, small work roll diameter, large mill rigidity, and small size and light weight, multi-roll mills are more suitable for the process needs of modern ultra-thin strip production and manufacturing.

[0003] Among multi-roll rolling mills, the 18-roll mill is an important type. It not only possesses the control methods of a conventional six-roll mill, but also achieves smooth rolling of extremely thin strips by reducing the work roll diameter and adding four sets of side support devices. However, in the mill parameter design process, roll diameter design and roll system configuration are the most critical steps. Roll diameter refers to the size of each roll, while roll system configuration refers to the arrangement of the roll positions, dimensions, and number. Both have a crucial impact on the rolling quality and process control of metal sheets. Regarding roll diameter design, the roll diameter directly affects the magnitude of the extrusion impulse during the rolling process, thus influencing the width, thickness, shape, and physical and mechanical properties of the rolled product. Therefore, determining a suitable roll diameter has a direct impact on the mill's operating efficiency and rolling quality. Regarding roll system configuration, a reasonable roll system design can maintain product stability and consistency, improve rolling accuracy, and reduce vibration, noise, and energy consumption during the rolling process, resulting in better rolling performance. Therefore, for 18-roll mills, how to achieve roll diameter design and roll system configuration has become the key to the green development of metal strip towards thinner and stronger materials. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for designing the roll diameter and configuring the roll system for an 18-roll rolling mill for cold rolling stainless steel. This invention utilizes a minimum rollable thickness model to initially determine the range of work roll diameters, and then determines suitable work roll diameters based on actual production needs. Based on the given work roll diameters, the invention further determines the diameters of the intermediate rolls, support rolls, side support rolls, and backing rolls, and uses relevant formulas from mechanics of materials and Hertzian theory to verify the strength of the roll system. Simultaneously, regarding the roll system configuration, considering the similarities and differences between an 18-roll rolling mill and a 6-roll rolling mill, and taking into account the functions of the twelve rolls involved in the side support device of the 18-roll rolling mill, while also avoiding interference between rolls, a roll system configuration method suitable for the current roll diameter sizes of the 18-roll rolling mill is proposed.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] This invention provides a method for designing the roll diameter of an 18-roll rolling mill for cold rolling of stainless steel, comprising the following steps:

[0007] Step 1: Determine the work roll diameter initially based on the minimum rollable thickness formula;

[0008] Step 2: Determine the size of other roller systems based on the diameter of the work roller;

[0009] Step 3: Perform strength verification calculations on the work roll, intermediate roll, support roll, side support roll, and backing roll to determine whether the roll system size is reasonably designed. The specific steps are as follows:

[0010] Step 3.1: Allocate the rolling passes according to actual needs;

[0011] Step 3.2: Calculate the rolling force for each pass using the multi-pass average unit pressure formula;

[0012] Step 3.3: Find the maximum rolling force as the standard for measuring strength in subsequent verification calculations;

[0013] Step 3.4: Calculate the combined stress using the fourth strength theory to verify the strength of each roll;

[0014] Step 3.5: Use Hertz's formula to perform contact stress verification calculations between the rolls.

[0015] Furthermore, the formula for the minimum rollable thickness in step 1 is as follows:

[0016]

[0017] in, This refers to the theoretical minimum rollable thickness of the rolling mill equipment. The diameter of the work roll body, The coefficient of friction between the strip and the work roll is 0.05 to 0.08. The yield strength of the material before rolling. The pre-tension acting on the rolled piece, This is the elastic modulus of the work roll material.

[0018] Furthermore, the specific steps of step 2 are as follows:

[0019] Step 2.1: Calculate the diameter of the intermediate roll body according to the following formula. Support roller body diameter ;

[0020]

[0021]

[0022] Step 2.2: Calculate the diameter of the side support roller body according to the following formula. Backing roller body diameter ;

[0023]

[0024]

[0025] Step 2.3: Calculate the other design parameters of the work roll, intermediate roll, support roll, side support roll, and backing roll according to the following formulas;

[0026]

[0027]

[0028] in, The term "roll diameter" is used in a broad sense, encompassing the diameters of work rolls, intermediate rolls, support rolls, side support rolls, and backing rolls. The journal diameter is used in a broad sense, including the diameters of the work roll, intermediate roll, support roll, side support roll, and backing roll. The journal length is a general term that includes the lengths of the work roll, intermediate roll, support roll, side support roll, and backing roll.

[0029] Furthermore, the calculation steps in step 3.2 are as follows:

[0030] Step 3.2.1: Calculation of reduction amount:

[0031]

[0032] in, For the first The amount of pressure applied per pass. For the first The thickness of the stainless steel exit in each pass. For the first The thickness of the stainless steel exit in each pass;

[0033] Step 3.2.2: The first Strength calculation of strip steel per pass:

[0034] like ,

[0035] like ,

[0036] in, For the first Strength of strip steel per pass For the strength of the first strip, For the thickness of the incoming material, For product thickness;

[0037] Step 3.2.3: The Calculation of deformation resistance for each pass:

[0038]

[0039] in, For the first Deformation resistance of the track, For the first Rolling speed per pass;

[0040] Step 3.2.4: The Calculation of contact arc length per pass:

[0041]

[0042] in, For the first Contact arc length of each pass, The diameter of the work roll body;

[0043] Step 3.2.5: The Calculation of rolling force per pass:

[0044]

[0045] in, For the first Rolling force per pass, For the first Average tensile stress per pass For the first Average thickness per pass This refers to the width of the strip steel.

[0046] Furthermore, the specific steps of step 3.4 are as follows:

[0047] Step 3.4.1: Calculation of bending moment at the central section of the roller body:

[0048]

[0049] in, The bending moment at the central section of the roller body. Total rolling pressure, The center distance between the two screws. This refers to the length of the roll body.

[0050] Step 3.4.2: Calculation of bending stress at the central section of the roller body:

[0051]

[0052] in, The bending stress is at the central section of the roller body.

[0053] Step 3.4.3: Calculation of bending moment at the critical section of the roller diameter:

[0054]

[0055] in, The bending moment at the critical section of the roller diameter. This is the distance from the center line of the screw to the edge of the roller body;

[0056] Step 3.4.4: Calculation of bending and torsional stresses on the roll diameter:

[0057]

[0058]

[0059]

[0060]

[0061] in, The bending stress is the diameter of the roller. The torsional stress is the diameter of the roller. This represents the maximum bending stress along the roller diameter. This represents the maximum torsional stress on the roller diameter. To resist bending moment, For torsional moment, The section modulus is the bending section modulus. The section modulus is the torsional section modulus. and The stress concentration factor;

[0062] Step 3.4.5: Roll strength check:

[0063]

[0064] in, The combined stress is calculated using the fourth strength theory.

[0065] Furthermore, the Hertz formula in step 3.5 is as follows:

[0066]

[0067] ,

[0068] in, The unit load applied across the length of the roll surface is given by , where b is half the width of the contact area between the roll and the strip. , and , It refers to the diameter and radius of the two contacting rolls. , It is a coefficient related to the roll material. , It is the Poisson's ratio of the materials of the contacting rolls. , The elastic modulus of the materials of the contacting rolls.

[0069] Another aspect of the present invention provides a method for configuring the roll system of an 18-roll mill for cold rolling of stainless steel, comprising the following steps:

[0070] Step 1: Configure the roller system of the work roll, intermediate roll, and support roll. Specifically, from top to bottom, set up the upper support roll assembly, upper intermediate roll assembly, upper work roll assembly, lower work roll assembly, lower intermediate roll assembly, and lower support roll assembly. Among them, the upper intermediate roll assembly and the lower intermediate roll assembly are drive rolls.

[0071] Step 2: Configure the side support rollers and intermediate rollers as follows:

[0072] Step 2.1: Configure the side support roller and the work roller tangentially;

[0073] Step 2.2: To ensure that the side support roller can effectively support the work roller, define the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line. maximum value ;

[0074] Step 2.3: To avoid interference between the side support roller and the intermediate roller, calculate the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line based on the geometric relationship of the roller system. minimum value ;

[0075] Step 2.4: Based on Steps 2.2 and 2.3, obtain... The range of values ​​for ;

[0076] Step 3: Configure the roller system of backing roller 1, backing roller 2, and side support roller. The specific steps are as follows:

[0077] Step 3.1: Arrange the side support rollers tangentially to backing roller 1 and backing roller 2 respectively;

[0078] Step 3.2: To avoid interference between the backing roller 1 and the intermediate roller, the midpoint of the line connecting the centers of the backing roller 1 and the backing roller 2, and the counterclockwise angle between the line connecting the centers of the side support rollers and the horizontal line are calculated based on geometric relationships. minimum value ;

[0079] Step 3.3: To avoid interference between the symmetrical backing rollers 2 of the roller system, the midpoint of the line connecting the centers of backing roller 1 and backing roller 2, and the counterclockwise angle between the line connecting the center of the side support roller and the horizontal line are calculated based on geometric relationships. maximum value ,

[0080] Step 3.4: Based on Steps 3.2 and 3.3, obtain... The range of values ​​for ;

[0081] Step 4: Combine steps 1 to 3 to determine the roll system configuration of the 18-roll mill.

[0082] Furthermore, in step 2.3 The calculation steps are as follows:

[0083] Step 2.3.1: The angle between the line connecting the centers of the work roll and the side support roll and the line connecting the centers of the work roll and the intermediate roll. The angle between the line connecting the center of the side support roller and the center of the work roller and the horizontal line. The relationship between them is:

[0084]

[0085] Step 2.3.2: When the side support roller and the intermediate roller interfere with each other and are tangential, The value is :

[0086]

[0087] Step 2.3.3: Based on Step 2.3.1 and Step 2.3.2, calculate... :

[0088]

[0089] .

[0090] Furthermore, in step 3.2 The calculation steps are as follows:

[0091] Step 3.2.1: Calculate the length of the line connecting the centers of backing roller 1 and backing roller 2 using the following formula. :

[0092]

[0093] Step 3.2.2: Calculate the angle between the line connecting the centers of backing roller 1 and side support roller and the line connecting the centers of backing roller 2 and side support roller using the following formula. :

[0094]

[0095] Step 3.2.3: Calculate the length of the line connecting the centers of the side support roller and the intermediate roller using the following formula: :

[0096]

[0097]

[0098] Step 3.2.4: Calculate the angle between the line connecting the centers of the side support roller and the intermediate roller and the line connecting the centers of the side support roller and the work roller using the following formula. :

[0099]

[0100] Step 3.2.5: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies It changes with the angle; when the backing roller and the intermediate roller interfere, its value is... The calculation formula is as follows:

[0101]

[0102] Step 3.2.6: Calculate using the following formula :

[0103] .

[0104] Furthermore, in step 3.3 The calculation steps are as follows:

[0105] Step 3.3.1: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies The value changes with the angle; when the symmetrical backing rollers 2 of the roller system interfere with each other, its value is... The calculation formula is as follows:

[0106]

[0107] Step 3.3.2: Calculate using the following formula :

[0108] .

[0109] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0110] This invention combines practical production with mathematical derivation. It uses the minimum rollable thickness formula to determine the appropriate work roll diameter, and calculates the diameters of the intermediate roll, support roll, side support roll, and backing roll using an empirical formula for the diameter of an 18-roll mill. The rolls are then verified using material mechanics formulas and Hertz's formula. The rigorous mathematical calculations reflect the feasibility of the design to a certain extent. Because its structure adds four sets of side support devices to both sides of the work roll on the basis of the traditional HC-type six-roll mill, there is still a similarity in the roll system configuration. The work roll, intermediate roll, and support roll are configured according to the arrangement of a conventional six-roll mill. The support roll and backing roll are given their applicable range using geometric relationships and constraints. A reasonable roll diameter design and roll system configuration can, firstly, reduce the deformation stress of the rolled piece, reduce surface defects, and improve the surface finish and dimensional accuracy of the rolled piece; secondly, it can reduce rolling deformation, lower rolling pressure, and effectively prevent equipment vibration and impact, thereby improving the operational stability of the roll system. Attached Figure Description

[0111] Figure 1 Flowchart for calculating the roll diameter design and roll system configuration of an 18-roll mill;

[0112] Figure 2 This is a schematic diagram showing the positions of the side support roller system, work roller, intermediate roller, and support roller.

[0113] Figure 3 A schematic diagram of the roll system configuration for an 18-roll mill;

[0114] Figure 4 A schematic diagram showing the configuration of the work rolls, intermediate rolls, and support rolls of an 18-roll mill.

[0115] Figure 5 A three-dimensional schematic diagram of the roll system configuration for the side support device of an 18-roll mill;

[0116] Figure 6 A three-dimensional schematic diagram showing the configuration of the work rolls, intermediate rolls, and support rolls of an 18-roll mill.

[0117] Figure 7 A three-dimensional schematic diagram of the roll system configuration for an 18-roll mill;

[0118] Figure 8 This is a schematic diagram showing the position of the side support roller system;

[0119] Figure 9 This is a schematic diagram showing the positions of the side support roller and the work roller;

[0120] Figure 10 A schematic diagram of the position of the side support roller system when the backing roller and the intermediate roller interfere with each other;

[0121] Figure 11 A schematic diagram of the side support roller system position when the upper and lower backing rollers interfere with each other;

[0122] In the attached drawings, the following reference numerals are used: 1—upper support roller assembly; 2—upper intermediate roller assembly; 3—upper work roller assembly; 4—lower work roller assembly; 5—lower intermediate roller assembly; 6—lower support roller assembly; 7—side support roller assembly; 8—backing roller assembly; 9—frame. Detailed Implementation

[0123] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0124] Example 1

[0125] This embodiment provides a method for designing the roll diameter of an 18-roll rolling mill, with the specific steps as follows:

[0126] Step 1: Preliminarily determine the work roll diameter based on the minimum rollable thickness formula; the minimum rollable thickness formula is as follows:

[0127]

[0128] Taking a 650mm 18-roll mill as an example, the work roll material is selected as semi-high-speed alloy steel, and the given production thickness of the mill is 0.05mm (generally, the production thickness is greater than...). (thickness), coefficient of friction between strip and work roll The elastic modulus of the work roll material Kilogram / Yield strength of material before rolling Kilogram / The forward tension acting on the rolled piece Kilogram / Substituting the above data into the minimum rollable thickness formula yields: For ease of roll production and considering the roll body length of 650mm, the work roll diameter is determined to be... .

[0129] Step 2: Determine the size of other rollers based on the diameter of the work roller. The specific steps are as follows:

[0130] Step 2.1: Given the empirical formula for the roll diameter of a six-roll mill, and utilizing the characteristic that the eighteen-roll mill's structure is a significantly reduced work roll diameter due to the addition of four side support devices to the traditional six-roll mill, the intermediate roll diameter of the eighteen-roll mill can be reasonably extrapolated to obtain the intermediate roll diameter. Support roller body diameter The calculation formula is as follows:

[0131]

[0132]

[0133] Will Substituting into the above formula, the calculation is as follows:

[0134]

[0135]

[0136] Select the diameter of the intermediate roller body Support roller body diameter .

[0137] Step 2.2: The side support roller and the work roller have similar diameters, with the side support roller being slightly smaller than the work roller diameter; the backing roller should also be slightly smaller than the side support roller due to structural requirements. This means that a certain mathematical relationship can be obtained with the work roller to meet the design requirements of the side support roller and the backing roller. The side support roller's body diameter... Backing roller body diameter The calculation formula is as follows:

[0138]

[0139]

[0140] Will Substituting into the above formula, the calculation is as follows:

[0141]

[0142]

[0143] Select the diameter of the side support roller body Backing roller body diameter .

[0144] Step 2.3: Calculate the other design parameters of the work roll, intermediate roll, support roll, side support roll, and backing roll according to the following formulas;

[0145]

[0146]

[0147] in, The term "roll diameter" is used in a broad sense, encompassing the diameters of work rolls, intermediate rolls, support rolls, side support rolls, and backing rolls. The journal diameter is used in a broad sense, including the diameters of the work roll, intermediate roll, support roll, side support roll, and backing roll. The journal length is a general term that includes the lengths of the work roll, intermediate roll, support roll, side support roll, and backing roll.

[0148] The values ​​of each parameter are as follows:

[0149] Table 1 Summary of parameters for work rolls, intermediate rolls, and support rolls

[0150] Work roll 80 650 40 40 intermediate roll 175 800 90 90 support rollers 545 650 280 260

[0151] Table 2 Summary of parameters for side support rollers and backing rollers

[0152] Side support rollers 75 650 40 35 Backing roller 65 650 35 30

[0153] Step 3: Perform strength verification calculations on the work roll, intermediate roll, support roll, side support roll, and backing roll to determine whether the roll system size is reasonably designed. The specific steps are as follows:

[0154] Step 3.1: In this embodiment, the initial thickness of the incoming material is selected as 1.5mm and the production thickness is 0.05mm for calculation. Other thicknesses within this range are flexibly adjusted in the actual rolling passes. Due to the work hardening phenomenon during the rolling process, the strip rolling cannot be completed in one go. Therefore, the passes are allocated according to actual needs, as follows:

[0155] Table 3 Track Allocation Table

[0156] 1 1.5 0.76 49.33% 2 0.76 0.4 47.37% 3 0.4 0.22 45% 4 0.22 0.14 36.36% 5 0.14 0.09 35.71% 6 0.09 0.065 27.78% 7 0.065 0.05 23.08%

[0157] Step 3.2: Calculate the rolling force for 7 passes using the multi-pass average unit pressure formula. The calculation steps are as follows:

[0158] Step 3.2.1: Calculation of reduction amount:

[0159]

[0160] in, For the first The amount of pressure applied per pass. For the first The thickness of the stainless steel exit in each pass. For the first The thickness of the stainless steel exit in each pass;

[0161] Step 3.2.2: The first Strength calculation of strip steel per pass:

[0162] like

[0163] like ,

[0164] in, For the first Strength of strip steel per pass For the strength of the first strip, For the thickness of the incoming material, For product thickness;

[0165] Step 3.2.3: The Calculation of deformation resistance for each pass:

[0166]

[0167] in, For the first Deformation resistance of the track, For the first Rolling speed per pass;

[0168] Step 3.2.4: The Calculation of contact arc length per pass:

[0169]

[0170] in, For the first Contact arc length of each pass, The diameter of the work roll body;

[0171] Step 3.2.5: The Calculation of rolling force per pass:

[0172]

[0173] in, For the first Rolling force per pass, For the first Average tensile stress per pass For the first Average thickness per pass This refers to the width of the strip steel.

[0174] The rolling forces for the seven passes were calculated using the above steps, and the results are shown below:

[0175] Table 4 Rolling Force Values

[0176] Rolling force (KN) 534.73 505.31 454.24 411.44 379.65 356.70 342.78

[0177] Step 3.3: Comparing the rolling forces of each pass, it was found that the maximum rolling force occurred in the first pass, with a value of 534.72 KN. This value was used as the standard for measuring strength in subsequent verification calculations.

[0178] Step 3.4: With a workpiece width of 400mm, the combined stress is calculated using the fourth strength theory in mechanics of materials to check the strength of each roll. The specific steps are as follows:

[0179] Step 3.4.1: Calculation of bending moment at the central section of the roller body:

[0180]

[0181] in, The bending moment at the central section of the roller body. Total rolling pressure, The center distance between the two screws. This refers to the length of the roll body.

[0182] Step 3.4.2: Calculation of bending stress at the central section of the roller body:

[0183]

[0184] in, The bending stress is at the central section of the roller body.

[0185] Step 3.4.3: Calculation of bending moment at the critical section of the roller diameter:

[0186]

[0187] in, The bending moment at the critical section of the roller diameter. This is the distance from the center line of the screw to the edge of the roller body;

[0188] Step 3.4.4: Calculation of bending and torsional stresses on the roll diameter:

[0189]

[0190]

[0191] Because stress concentration occurs at the point where the roll cross-section changes from the roll diameter to the roll body, the stress calculated by the above formula is only the nominal stress. The actual stress needs to be multiplied by a stress concentration factor. and This coefficient is related to the roll body diameter, roll diameter, and transition fillet radius, and its formula is as follows:

[0192]

[0193]

[0194] in, The bending stress is the diameter of the roller. The torsional stress is the diameter of the roller. This represents the maximum bending stress along the roller diameter. This represents the maximum torsional stress on the roller diameter. To resist bending moment, For torsional moment, The section modulus is the bending section modulus. The section modulus is the torsional section modulus. and The stress concentration factor;

[0195] Step 3.4.5: Roll strength check:

[0196]

[0197] in, The combined stress is calculated using the fourth strength theory.

[0198] The above calculations show that all rolls have been successfully verified, and the combined stress of each roll is as follows:

[0199] Table 5 Combined stress of each roll

[0200] Composite stress (MPa) 1016.79 237.65 74.38 1022.11 1247.85

[0201] Step 3.5: Perform contact stress verification calculations between the rolls using Hertz's formula; the Hertz formula is as follows:

[0202]

[0203] ,

[0204] in, The unit load applied across the length of the roll surface is given by , where b is half the width of the contact area between the roll and the strip. , and , It refers to the diameter and radius of the two contacting rolls. , It is a coefficient related to the roll material. , It is the Poisson's ratio of the materials of the contacting rolls. , The elastic modulus of the materials of the contacting rolls.

[0205] (1) Check of contact stress between work roll and intermediate roll

[0206] Both the work roll and the intermediate roll are made of semi-high-speed alloy steel with an elastic modulus of 210,000. .

[0207] Substitution We can obtain:

[0208]

[0209] According to Table 6, the hardness of this roll is... Therefore, the stress value calculated according to the formula is less than the allowable stress. This indicates that the contact stress is within a suitable range and meets the usage requirements.

[0210] Table 6 Allowable contact stress values

[0211]

[0212] Based on the motion of the 18-roll system, it can be inferred that the main cause of roll surface spalling is the change in shear stress in both the forward and reverse directions during the opposing rotation of the rolls within the contact area. Therefore, it is also necessary to check the maximum shear stress of the rolls. The formula for calculating the maximum shear stress is as follows:

[0213]

[0214] Substituting the relevant data, we get:

[0215]

[0216] The allowable stress can be found from Table 6. The value obtained by the above formula is less than its allowable stress value, which also meets the usage requirements.

[0217] (2) Check of contact stress between intermediate roll and support roll

[0218] The intermediate roll and support roll are made of semi-high-speed alloy steel and Cr5 forged steel, respectively, with elastic moduli of 210,000. and 200000 .

[0219] First calculate , :

[0220]

[0221] Substitution We can obtain:

[0222]

[0223] According to Table 6, the hardness of this roll is... Therefore, the stress value calculated according to the formula is less than the allowable stress. This indicates that the contact stress is within a suitable range and meets the usage requirements.

[0224] Similarly, we can conclude that:

[0225] Substituting the relevant data, we can obtain:

[0226]

[0227] The allowable stress can be found from Table 6. The value obtained by the above formula is less than its allowable stress value, which also meets the usage requirements.

[0228] Example 2

[0229] This embodiment provides a method for configuring the roll system of an 18-roll rolling mill. Taking the 650mm 18-roll rolling mill in Embodiment 1 as an example, the roll diameters of each roll are as follows: [Example: Work roll diameter...] Intermediate roll body diameter Support roller body diameter Side support roller body diameter Backing roller body diameter .

[0230] The specific steps for configuring the roller system are as follows:

[0231] Step 1: Configure the work roll, intermediate roll, and support roll system in the same way as the traditional six-roll mill. From top to bottom, the upper support roll assembly 1, upper intermediate roll assembly 2, upper work roll assembly 3, lower work roll assembly 4, lower intermediate roll assembly 5, and lower support roll assembly 6 are arranged sequentially. The upper intermediate roll assembly 2 and lower intermediate roll assembly 5 are drive rolls.

[0232] Step 2: Configure the side support rollers and intermediate rollers as follows:

[0233] Step 2.1: Configure the side support roller and the work roller tangentially;

[0234] Step 2.2: To ensure that the side support roller can effectively support the work roller, define the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line. maximum value ;

[0235] Step 2.3: To avoid interference between the side support roller and the intermediate roller, calculate the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line based on the geometric relationship of the roller system. minimum value The calculation steps are as follows:

[0236] Step 2.3.1: The angle between the line connecting the centers of the work roll and the side support roll and the line connecting the centers of the work roll and the intermediate roll. The angle between the line connecting the center of the side support roller and the center of the work roller and the horizontal line. The relationship between them is:

[0237]

[0238] Step 2.3.2: When the side support roller and the intermediate roller interfere with each other and are tangential, The value is :

[0239]

[0240] Step 2.3.3: Based on Step 2.3.1 and Step 2.3.2, calculate... :

[0241]

[0242] Step 2.4: Based on Steps 2.2 and 2.3, obtain... The range of values ​​for:

[0243]

[0244] Select The value is .

[0245] Step 3: Configure the roller system of backing roller 1, backing roller 2, and side support roller. The specific steps are as follows:

[0246] Step 3.1: Arrange the side support rollers tangentially to backing roller 1 and backing roller 2 respectively;

[0247] Step 3.2: To avoid interference between the backing roller 1 and the intermediate roller, the midpoint of the line connecting the centers of the backing roller 1 and the backing roller 2, and the counterclockwise angle between the line connecting the centers of the side support rollers and the horizontal line are calculated based on geometric relationships. minimum value The calculation steps are as follows:

[0248] Step 3.2.1: Calculate the length of the line connecting the centers of backing roller 1 and backing roller 2 using the following formula. :

[0249]

[0250] Select The value is 70mm.

[0251] Step 3.2.2: Calculate the angle between the line connecting the centers of backing roller 1 and side support roller and the line connecting the centers of backing roller 2 and side support roller using the following formula. :

[0252]

[0253] Step 3.2.3: Calculate the length of the line connecting the centers of the side support roller and the intermediate roller using the following formula: :

[0254]

[0255]

[0256]

[0257]

[0258] Step 3.2.4: Calculate the angle between the line connecting the centers of the side support roller and the intermediate roller and the line connecting the centers of the side support roller and the work roller using the following formula. :

[0259]

[0260] Step 3.2.5: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies It changes with the angle; when the backing roller and the intermediate roller interfere, its value is... The calculation formula is as follows:

[0261]

[0262] Step 3.2.6: Calculate using the following formula :

[0263]

[0264] Step 3.3: To avoid interference between the symmetrical backing rollers 2 of the roller system, the midpoint of the line connecting the centers of backing roller 1 and backing roller 2, and the counterclockwise angle between the line connecting the center of the side support roller and the horizontal line are calculated based on geometric relationships. maximum value The calculation steps are as follows:

[0265] Step 3.3.1: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies The value changes with the angle; when the symmetrical backing rollers 2 of the roller system interfere with each other, its value is... The calculation formula is as follows:

[0266]

[0267] Step 3.3.2: Calculate using the following formula :

[0268]

[0269] Step 3.4: Based on Steps 3.2 and 3.3, obtain... The range of values ​​for:

[0270]

[0271] Select The value is .

[0272] Step 4: Combine steps 1 to 3 to determine the roll system configuration of the 18-roll mill.

[0273] The above description is only for better explaining the embodiments of the present invention and is not intended to limit them. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention shall fall within the scope of the present invention.

Claims

1. A method for designing the roll diameter of an 18-roll rolling mill for cold rolling of stainless steel, characterized in that, Includes the following steps: Step 1: Determine the work roll diameter initially based on the minimum rollable thickness formula; Step 2: Determine the size of other roller systems based on the diameter of the work roller; Step 3: Perform strength verification calculations on the work roll, intermediate roll, support roll, side support roll, and backing roll to determine whether the roll system size is reasonably designed. The specific steps are as follows: Step 3.1: Allocate the rolling passes according to actual needs; Step 3.2: Calculate the rolling force for each pass using the multi-pass average unit pressure formula; Step 3.3: Find the maximum rolling force as the standard for measuring strength in subsequent verification calculations; Step 3.4: Calculate the combined stress using the fourth strength theory to verify the strength of each roll; Step 3.5: Use Hertz's formula to calculate and verify the contact stress between the rolls; The calculation steps in step 3.2 are as follows: Step 3.2.1: Calculation of reduction amount: in, For the first The amount of pressure applied per pass. For the first The thickness of the stainless steel exit in each pass. For the first The thickness of the stainless steel exit in each pass; Step 3.2.2: The first Strength calculation of strip steel per pass: like , like , in, For the first Strength of strip steel per pass For the strength of the first strip, For the thickness of the incoming material, For product thickness; Step 3.2.3: The Calculation of deformation resistance per pass: in, For the first Deformation resistance of the track, For the first Rolling speed per pass; Step 3.2.4: The Calculation of contact arc length per pass: in, For the first Contact arc length of each pass, The diameter of the work roll body; Step 3.2.5: The Calculation of rolling force per pass: in, For the first Rolling force per pass, For the first Average tensile stress per pass For the first Average thickness per pass This refers to the width of the strip steel.

2. The roll diameter design method for an 18-roll rolling mill for cold rolling of stainless steel according to claim 1, characterized in that, The formula for the minimum rollable thickness in step 1 is as follows: in, This refers to the theoretical minimum rollable thickness of the rolling mill equipment. The diameter of the work roll body, The coefficient of friction between the strip and the work roll is 0.05 to 0.

08. The yield strength of the material before rolling. The pre-tension acting on the rolled piece, This is the elastic modulus of the work roll material.

3. The roll diameter design method for an 18-roll rolling mill for cold rolling of stainless steel according to claim 1, characterized in that, The specific steps of step 2 are as follows: Step 2.1: Calculate the diameter of the intermediate roll body according to the following formula. Support roller body diameter ; Step 2.2: Calculate the diameter of the side support roller body according to the following formula. Backing roller body diameter ; Step 2.3: Calculate the other design parameters of the work roll, intermediate roll, support roll, side support roll, and backing roll according to the following formulas; in, The term "roll diameter" is used in a broad sense, encompassing the diameters of work rolls, intermediate rolls, support rolls, side support rolls, and backing rolls. The journal diameter is used in a broad sense, including the diameters of the work roll, intermediate roll, support roll, side support roll, and backing roll. The journal length is a general term that includes the lengths of the work roll, intermediate roll, support roll, side support roll, and backing roll.

4. The roll diameter design method for an 18-roll rolling mill for cold rolling of stainless steel according to claim 1, characterized in that, The specific steps of step 3.4 are as follows: Step 3.4.1: Calculation of bending moment at the central section of the roller body: in, The bending moment at the central section of the roller body. Total rolling pressure, The center distance between the two screws. This refers to the length of the roll body. Step 3.4.2: Calculation of bending stress at the central section of the roller body: in, The bending stress is at the central section of the roller body. Step 3.4.3: Calculation of bending moment at the critical section of the roller diameter: in, The bending moment at the critical section of the roller diameter. This is the distance from the center line of the screw to the edge of the roller body; Step 3.4.4: Calculation of bending and torsional stresses on the roll diameter: in, The bending stress is the diameter of the roller. The torsional stress is the diameter of the roller. This represents the maximum bending stress along the roller diameter. This represents the maximum torsional stress on the roller diameter. To resist bending moment, For torsional moment, The section modulus is the bending section modulus. The section modulus is the torsional section modulus. and The stress concentration factor; Step 3.4.5: Roll strength check: in, The combined stress is calculated using the fourth strength theory.

5. The roll diameter design method for an 18-roll rolling mill for cold rolling of stainless steel according to claim 1, characterized in that, The Hertz formula in step 3.5 is as follows: , in, The unit load applied across the length of the roll surface is given by , where b is half the width of the contact area between the roll and the strip. , and , It refers to the diameter and radius of the two contacting rolls. , It is a coefficient related to the roll material. , It is the Poisson's ratio of the materials of the contacting rolls. , The elastic modulus of the materials of the contacting rolls.

6. A method for configuring the roll system of an 18-roll rolling mill for cold rolling of stainless steel based on the roll diameter design method according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Configure the roller system of the work roll, intermediate roll, and support roll. Specifically, from top to bottom, set up the upper support roll assembly, upper intermediate roll assembly, upper work roll assembly, lower work roll assembly, lower intermediate roll assembly, and lower support roll assembly. Among them, the upper intermediate roll assembly and the lower intermediate roll assembly are drive rolls. Step 2: Configure the side support rollers and intermediate rollers as follows: Step 2.1: Configure the side support roller and the work roller tangentially; Step 2.2: To ensure that the side support roller can effectively support the work roller, define the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line. maximum value ; Step 2.3: To avoid interference between the side support roller and the intermediate roller, calculate the angle between the line connecting the centers of the side support roller and the work roller and the horizontal line based on the geometric relationship of the roller system. minimum value ; Step 2.4: Based on Steps 2.2 and 2.3, obtain... The range of values ​​for ; Step 3: Configure the roller system of backing roller 1, backing roller 2, and side support roller. The specific steps are as follows: Step 3.1: Arrange the side support rollers tangentially to backing roller 1 and backing roller 2 respectively; Step 3.2: To avoid interference between the backing roller 1 and the intermediate roller, the midpoint of the line connecting the centers of the backing roller 1 and the backing roller 2, and the counterclockwise angle between the line connecting the centers of the side support rollers and the horizontal line are calculated based on geometric relationships. minimum value ; Step 3.3: To avoid interference between the symmetrical backing rollers 2 of the roller system, the midpoint of the line connecting the centers of backing roller 1 and backing roller 2, and the counterclockwise angle between the line connecting the center of the side support roller and the horizontal line are calculated based on geometric relationships. maximum value , Step 3.4: Based on Steps 3.2 and 3.3, obtain... The range of values ​​for ; Step 4: Determine the roll system configuration of the 18-roll mill by combining steps 1 to 3; In step 2.3 The calculation steps are as follows: Step 2.3.1: The angle between the line connecting the centers of the work roll and the side support roll and the line connecting the centers of the work roll and the intermediate roll. The angle between the line connecting the center of the side support roller and the center of the work roller and the horizontal line. The relationship between them is: Step 2.3.2: When the side support roller and the intermediate roller interfere with each other and are tangential, The value is : Step 2.3.3: Based on Step 2.3.1 and Step 2.3.2, calculate... : ； In step 3.2 The calculation steps are as follows: Step 3.2.1: Calculate the length of the line connecting the centers of backing roller 1 and backing roller 2 using the following formula. : Step 3.2.2: Calculate the angle between the line connecting the centers of backing roller 1 and side support roller and the line connecting the centers of backing roller 2 and side support roller using the following formula. : Step 3.2.3: Calculate the length of the line connecting the centers of the side support roller and the intermediate roller using the following formula: : Step 3.2.4: Calculate the angle between the line connecting the centers of the side support roller and the intermediate roller and the line connecting the centers of the side support roller and the work roller using the following formula. : Step 3.2.5: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies It changes with the angle; when the backing roller and the intermediate roller interfere, its value is... The calculation formula is as follows: Step 3.2.6: Calculate using the following formula : ； In step 3.3 The calculation steps are as follows: Step 3.3.1: The angle between the line connecting the centers of the side support roller and the backing roller 1 and the line connecting the centers of the side support roller and the intermediate roller. Size varies The value changes with the angle; when the symmetrical backing rollers 2 of the roller system interfere with each other, its value is... The calculation formula is as follows: Step 3.3.2: Calculate using the following formula : 。

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