Pass design method for transverse rolling mill

Abstract

The invention discloses a pass design method for transverse rolling mills, which comprises the following steps of: S1, determining the area of a rolled piece before entering a first rolling mill and the minimum area of the rolled piece after entering a second rolling mill, and calculating the total elongation coefficient according to the areas; s2, an average extension coefficient is set according to deformation requirements, and rolling passes are calculated; s3, according to the process requirement, distributing the extension coefficient of each pass, and determining the theoretical value of the cross section area of each pass; s4, hole pattern parameters of each pass are determined according to the cross section area of each pass; s5, calculating the cross section area of each pass, comparing the cross section area with a theoretical value, correcting pass parameters, and calculating the deformation of each pass; and S6, according to the deformation of each pass, checking whether the process requirement is met or not, checking whether the biting condition is met or not, checking and adjusting the roll gap size, and calculating whether the deformation of each pass meets the requirement or not when the roll gap changes or not, if any item is not met, returning to the step S3, and if all the items are met, drawing a pass graph according to the revised pass parameters. The deformation degree of each pass can meet the process requirement.

Description

Technical Field

[0001] The invention relates to the technical field of metal pressure processing, and in particular to a hole design method for a horizontal rolling mill. Background Art

[0002] The rolling mill for rolling small rounds uses a horizontal 320×5-frame rolling mill for production. Currently, most of the products produced are high-temperature alloys, corrosion-resistant alloys and some high-end stainless steels, which have very high requirements on internal quality and surface quality, and thus have strict requirements on the grain size and various structures of the steel.

[0003] At present, during the rolling process of steel in the rolling mill, the deformation of each pass is seriously uneven, and the grain state after subsequent heat treatment is mixed and the quality problems of missing items are serious. Based on the above reasons, the deformation of each specification rolled by the horizontal 320 rolling mill is analyzed. The analysis results show that the deformation of 2-5 frames of each specification tends to be balanced, and the deformation of one frame is seriously uneven. Based on the current quality form, the hole type of one frame needs to be recalculated and designed at the current stage. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for designing a pass profile of a horizontal rolling mill, which can ensure that the degree of deformation of each pass meets the process requirements.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0006] A method for designing a pass profile of a horizontal rolling mill comprises the following steps:

[0007] S1. Determine the pre-rolling area of ​​the rolled piece before entering the first rolling mill and the minimum area required for entering the second rolling mill, and calculate the total elongation coefficient of the rolled piece based on the determined area;

[0008] S2. Set the average elongation coefficient according to the deformation requirements and calculate the rolling passes;

[0009] S3. Allocate the elongation coefficient of each pass according to the process requirements and determine the theoretical value of the cross-sectional area of ​​each pass;

[0010] S4. Determine the pass parameters of each pass according to the cross-sectional area of ​​each pass;

[0011] S5. Calculate the cross-sectional area of ​​each pass and modify the pass parameters by comparing with the theoretical values ​​in step S3 to calculate the deformation of each pass;

[0012] S6. Calculate whether the deformation of each pass meets the process requirements, and on this basis calculate whether the bite condition is met, and calculate the roll gap size, and calculate whether the deformation of each pass meets the requirements when the roll gap changes. If any one of them is not met, return to step S3, if all are met, proceed to step S7;

[0013] S7. Draw a hole diagram according to the revised hole parameters;

[0014] S8. Reasonably configure the hole pattern on the roller.

[0015] Preferably, in step S1, the rolled piece is rolled into a bar with a diameter of 12 mm, and the area of ​​the rolled piece before rolling is 2205.77 mm 2 , the minimum area required to enter the second rolling mill is 900mm 2 , then the total elongation coefficient is μ ∑ =2205.77 / 900≈2.45.

[0016] Preferably, the step S2 is specifically as follows: according to the production experience data under the deformation requirements, the average elongation coefficient is set, and the average elongation coefficient μ is pre-set. p =1.15, then according to the formula for calculating the rolling pass, we can get the rolling pass n = logμ ∑ / logμ p =log2.45 / log1.15≈6.

[0017] Preferably, the step S3 is specifically as follows: according to the principle of elongation coefficient allocation from small to large and then to small, the elongation coefficients of each pass are temporarily set from 1 to 6 as μ1=1.13, μ2=1.16, μ3=1.19, μ4=1.2, μ5=1.17, and μ6=1.12, and after allocating the elongation coefficients of each pass, the allocation is checked, that is, μ ∑ ′ =μ1*μ2*μ3*μ4*μ5*μ6=1.13*1.16*1.19*1.2*1.17*1.12≈2.453, μ ∑ ′ ≈μ ∑ , then the requirements are met; after the requirements are met, the cross-sectional area of ​​each pass is determined according to the elongation coefficient of each pass, F n-1 =F n *μ n , and F0 is the area of ​​the billet entering the first hole, and F6 is the minimum area required to enter the second rolling mill determined in step S1.

[0018] Preferably, the step S4 is specifically:

[0019] The order of the 6 hole types used is determined as follows: diamond hole type-flat box hole type-vertical box hole type-flat box hole type-vertical box hole type-flat box hole type. According to the formula F n-1 =F n *μ n Calculate the area of ​​each pass, and then determine the side length a of the rhombus hole according to F1. The dimensions of each part of the rhombus hole of the first pass are:

[0020] Side length

[0021] The composition height of the hole type h = (1.4 ~ 1.41)a;

[0022] The width of the hole is b = (1.41-1.42) a;

[0023] The height of the hole is Hk = (1.4 ~ 1.41)a-0.828R;

[0024] The width of the pass Bk = (1.41-1.42)as, where s is the roll gap value, s = (0.02-0.03)D, and D is the roll diameter;

[0025] Inner fillet radius R = (0.1 ~ 0.2)h;

[0026] Outer fillet radius r = (0.05-0.1)h;

[0027] The dimensions of each part of the second pass flat box pass are:

[0028] The width of the box Bk1=a+△b1, the height of the box Hk1=a-△h1, wherein △b1 is the first widening margin, the value range is 5-15mm; △h1 is the first pressing amount, the value range is 10-25mm;

[0029] B1=Bk1-y(Hk1-s), where y is the slope of the side wall of the hole, ranging from 5% to 20%; B1 is the groove bottom width of the second pass flat box hole;

[0030] Inner fillet radius R1 = (0.1-0.2) h1;

[0031] Outer fillet radius r1 = (0.05-0.1) h1;

[0032] The dimensions of each part of the third pass box pass are:

[0033] The width of the box is Bk2 = Hk1 + △b2, and the height of the box is Hk2 = Bk1 - △h2, wherein △b2 is the second widening margin, and the value range is 5-15mm; △h2 is the second pressing amount, and the value range is 10-25mm;

[0034] B2 = Bk2-y (Hk2-s), where B2 is the bottom width of the third pass of the vertical box hole;

[0035] Inner fillet radius R2 = (0.1-0.2) h2;

[0036] Outer fillet radius r2 = (0.05-0.1) h2;

[0037] According to the above method, the dimensions of the flat box hole profile of the fourth pass, the vertical box hole profile of the fifth pass and the flat box hole profile of the sixth pass are calculated in sequence.

[0038] Preferably, the step S5 specifically comprises: preliminarily drawing drawings of each hole type, calculating the cross-sectional area of ​​each pass according to each hole type drawing, revising the hole type parameters by comparing with the theoretical values ​​of step S3, and calculating the deformation of each pass.

[0039] Preferably, the method for calculating whether the process requirements are met according to the deformation amount of each pass in step S6 is:

[0040] ε n =(F (n-1) -F n ) / F (n-1) ≤20%, where ε is the deformation;

[0041] The method for calculating whether the bite condition is met is specifically as follows: according to the natural bite condition of the rolled piece, the relationship between the friction angle when the roller contacts the rolled piece and the bite angle is determined, and when β>ɑ, the rolled piece can be naturally bitten, wherein β is the friction angle when the roller contacts the rolled piece; ɑ is the bite angle;

[0042] The method for calculating whether the deformation amount of each pass meets the requirements when the roll gap changes is specifically: calculating the area of ​​each pass when the roll gap is at the maximum and minimum, and calculating whether the deformation amount of each pass is within the process requirement range.

[0043] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0044] The present invention calculates and balances the deformation of each hole type of the first rolling mill to make the grain size of the rolled steel tend to be uniform, avoids the problem of excessive temperature rise in the core of the rolled piece and missing items in internal quality inspection due to excessive deformation in individual passes, and achieves a good influence on the internal structure of the steel to ensure that the steel meets the requirements of technical conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of the present invention;

[0046] Figure 2 This is the rhombus hole design drawing for the first pass of the present invention;

[0047] Figure 3 It is the hole pattern diagram of the flat box of the second pass of the present invention;

[0048] Figure 4 This is the hole pattern diagram of the third pass of the box erection of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] A method for designing a pass profile of a horizontal rolling mill, which belongs to a method for designing a pass profile of a small bar produced on a horizontal rolling mill, Figure 1 As shown, the following steps are included:

[0051] S1. Determine the pre-rolling area of ​​the rolled piece before entering the first rolling mill and the minimum area required for entering the second rolling mill, and calculate the total elongation coefficient of the rolled piece based on the determined area.

[0052] For example, taking the rolling of 12mm Ф bars as an example, the area before rolling is 2205.77mm 2 , the minimum area required to enter the second rolling mill is 900mm 2 , then the total elongation coefficient is μ ∑ =2205.77 / 900≈2.45.

[0053] S2. Set the average elongation coefficient according to the deformation requirements and calculate the rolling passes.

[0054] This set of pass types is mainly used to produce high-temperature alloys, with small deformation requirements. The average elongation coefficient is generally determined based on production experience data. The average elongation coefficient μp is first set to 1.15, and the rolling pass n = logμ is obtained based on the formula for calculating the rolling pass. ∑ / logμ p =log2.45 / log1.15≈6, that is, 6 passes are required from the area before rolling to the minimum area required to enter the second rolling mill.

[0055] S3. Allocate the elongation coefficient of each pass according to the process requirements and determine the theoretical value of the cross-sectional area of ​​each pass.

[0056] The distribution of elongation coefficient is mainly based on the principle of elongation coefficient distribution. According to the principle of from small to large and then to small, the elongation coefficient of each pass is temporarily set as μ1=1.13, μ2=1.16, μ3=1.19, μ4=1.2, μ5=1.17, μ6=1.12 from 1 to 6, and a distribution check is required after the elongation coefficient of each pass is distributed, that is, μ ∑ ′

[0057] =μ1*μ2*μ3*μ4*μ5*μ6=1.13*1.16*1.19*1.2*1.17*1.12≈2.453, μ ∑ ′ ≈μ ∑ , then the requirements are met. After the requirements are met, the cross-sectional area of ​​each pass can be determined according to the elongation coefficient of each pass.

[0058] F n-1 =F n *μn , and F0 is the area of ​​the billet entering the first hole, and F6 is the minimum area required to enter the second rolling mill determined in step S1.

[0059] S4. Determine the hole parameters of each pass according to the cross-sectional area of ​​each pass.

[0060] First, determine the sequence of the six hole types to be used: rhombus hole type-flat box hole type-vertical box hole type-flat box hole type-vertical box hole type-flat box hole type. This hole type combination is used mainly considering that during the rolling process of high-temperature alloys, the billet has been heated at high temperature, the grains are coarse, and the bonding force between the grains is weak. If a large deformation surface is used, cracks or cracking is prone to occur. If a box hole type is used at the beginning, the billet is only subjected to pressure from the top and bottom, and the two sides are more likely to crack. The rhombus hole type is used in the first pass, mainly considering the advantages of this type of hole type, which can make the four sides of the rolled piece evenly processed. Through the four-sided compression of the rhombus hole type and the use of a smaller deformation amount, the grains are further refined, the bonding force between the grains is enhanced, and then the flat box and vertical box are combined to quickly reduce the cross-section and meet the material shape requirements for the next batch.

[0061] Then, according to formula F n-1 =F n *μ n Calculate the area of ​​each pass, and then determine the side length a of the rhombus hole according to F1. The dimensions of each part of the rhombus hole of the first pass are:

[0062] Side length

[0063] The composition height of the hole type h = (1.4 ~ 1.41)a;

[0064] The width of the hole is b = (1.41-1.42) a;

[0065] The height of the hole is Hk = (1.4 ~ 1.41)a-0.828R;

[0066] The width of the pass Bk = (1.41-1.42)as, where s is the roll gap value, s = (0.02-0.03)D, and D is the roll diameter;

[0067] Inner fillet radius R = (0.1 ~ 0.2)h;

[0068] The outer fillet radius r = (0.05-0.1)h.

[0069] Specifically, the first pass diamond hole design diagram is as follows: Figure 2 shown.

[0070] The dimensions of the second pass flat box hole are:

[0071] The width of the box Bk1=a+△b1, the height of the box Hk1=a-△h1, wherein △b1 is the first widening margin, the value range is 5-15mm; △h1 is the first pressing amount, the value range is 10-25mm;

[0072] B1=Bk1-y(Hk1-s), where y is the slope of the side wall of the hole, ranging from 5% to 20%; B1 is the groove bottom width of the second pass flat box hole;

[0073] Inner fillet radius R1 = (0.1-0.2) h1;

[0074] The outer fillet radius r1 = (0.05-0.1) h1.

[0075] Specifically, the second pass flat box hole design diagram is as follows: Figure 3 shown.

[0076] The dimensions of each part of the third pass box hole are:

[0077] The width of the box is Bk2 = Hk1 + △b2, and the height of the box is Hk2 = Bk1 - △h2, wherein △b2 is the second widening margin, and the value range is 5-15mm; △h2 is the second pressing amount, and the value range is 10-25mm;

[0078] B2 = Bk2-y (Hk2-s), where B2 is the bottom width of the third pass of the vertical box hole;

[0079] Inner fillet radius R2 = (0.1-0.2) h2;

[0080] The outer fillet radius r2 = (0.05-0.1)h2.

[0081] Specifically, the third pass box hole design diagram is as follows: Figure 4 shown.

[0082] According to the above method, the dimensions of the flat box hole of the fourth pass, the vertical box hole of the fifth pass and the flat box hole of the sixth pass are calculated in turn, and the hole of each pass is set with appropriate fillets.

[0083] S5. Calculate the cross-sectional area of ​​each pass and modify the hole parameters by comparing with the theoretical value of step S3 to calculate the deformation of each pass.

[0084] Specifically, preliminary drawings of each hole type are drawn, the cross-sectional area of ​​each pass is calculated according to each hole type drawing, and the hole type parameters are modified by comparing with the theoretical value of step S3 to calculate the deformation of each pass.

[0085] S6. Calculate whether the deformation amount of each pass meets the process requirements, and on this basis calculate whether the bite conditions are met, and calculate the adjustment roll gap size, and calculate whether the deformation amount of each pass meets the requirements when the roll gap changes. If any item is not met, return to step S3, if all are met, continue to step S7.

[0086] Specifically, the method for calculating whether the process requirements are met according to the deformation amount of each pass is:

[0087] ε n =(F (n-1) -F n ) / F (n-1) ≤20%, where ε is the deformation.

[0088] The method for calculating whether the bite condition is met is as follows: according to the natural bite condition of the rolled piece, the relationship between the friction angle when the roller contacts the rolled piece and the bite angle is determined. When β>ɑ, the rolled piece can be naturally bitten, where β is the friction angle when the roller contacts the rolled piece; ɑ is the bite angle.

[0089] The method for adjusting the roll gap size is specifically to simulate the up and down movement of the rolls during the production process.

[0090] The specific method for calculating whether the deformation of each pass meets the requirements when the roll gap changes is as follows: when the roll gap is adjusted, the area of ​​all the hole patterns arranged on the rolls will change accordingly. It is necessary to calculate the area of ​​each pass when the roll gap is at the maximum and minimum, and calculate whether the deformation of each pass is within the process requirements (the process requires that the deformation degree of each pass is ≤20%), as shown in the following table:

[0091]

[0092] It can be seen from the data in the table that the deformation is within 20%, which meets the process requirements.

[0093] In this step, if any item cannot be satisfied, it is necessary to return to step S3 to reallocate the elongation coefficients of each pass. If all items are satisfied, proceed to step S7.

[0094] S7. Draw a hole pattern diagram according to the modified hole pattern parameters.

[0095] S8. Reasonably configure the hole pattern on the roller.

[0096] The present invention calculates and balances the deformation of each hole type of the first rolling mill to make the grain size of the rolled steel tend to be uniform, avoids the problem of excessive temperature rise in the core of the rolled piece and missing items in internal quality inspection due to excessive deformation in individual passes, and achieves a good influence on the internal structure of the steel to ensure that the steel meets the requirements of technical conditions.

Claims

1. A method for designing the pass profile of a horizontal rolling mill. Features: The following steps are involved: S1. Determine the pre-rolling area of ​​the rolled piece before entering the first rolling mill and the minimum area required for entering the second rolling mill, and calculate the total elongation coefficient of the rolled piece based on the determined area; S2. Set the average elongation coefficient according to the deformation requirements and calculate the rolling passes; S3. Allocate the elongation coefficient of each pass according to the process requirements and determine the theoretical value of the cross-sectional area of ​​each pass; S4. Determine the pass parameters of each pass according to the cross-sectional area of ​​each pass; S5. Calculate the cross-sectional area of ​​each pass and modify the pass parameters by comparing with the theoretical values ​​in step S3 to calculate the deformation of each pass; S6. Calculate whether the deformation of each pass meets the process requirements, and on this basis calculate whether the bite condition is met, and calculate the roll gap size, and calculate whether the deformation of each pass meets the requirements when the roll gap changes. If any one of them is not met, return to step S3, if all are met, proceed to step S7; S7. Draw a hole diagram according to the revised hole parameters; S8. Reasonably configure the hole pattern on the roller.

2. A method for designing a pass profile of a horizontal rolling mill according to claim 1, Features: In step S1, the rolled piece is rolled into a bar with a diameter of 12 mm, and the area of ​​the rolled piece before rolling is 2205.77 mm 2 , the minimum area required to enter the second rolling mill is 900mm 2 , then the total elongation coefficient is μ ∑ =2205.77 / 900≈2.

45.

3. A method for designing a pass profile of a horizontal rolling mill according to claim 2, Features: The step S2 specifically includes: setting the average elongation coefficient according to the production experience data under the deformation requirements, first presetting the average elongation coefficient μ p =1.15, then according to the formula for calculating the rolling pass, we can get the rolling pass n = logμ ∑ / logμ p =log2.45 / log1.15≈6.

4. A method for designing a pass profile of a horizontal rolling mill according to claim 3, Features: The step S3 is specifically as follows: according to the principle of allocating elongation coefficients from small to large and then to small, the elongation coefficients of each pass are temporarily set from 1 to 6 as μ 1 =1.13, μ 2 =1.16, μ 3 =1.19, μ 4 =1.2, μ 5 =1.17, μ 6 =1.12, and after allocating the elongation coefficients of each pass, the distribution is checked, that is, μ ∑ ′ =μ 1 *μ 2 *μ 3 *μ 4 *μ 5 *μ 6 =1.13*1.16*1.19*1.2*1.17*1.12≈2.453, μ ∑ ′ ≈μ ∑ , then the requirements are met; after the requirements are met, the cross-sectional area of ​​each pass is determined according to the elongation coefficient of each pass, F n-1 =F n *μ n , and F 0 is the area of ​​the blank entering the first hole, F 6 It is the minimum area required for entering the second rolling mill determined in step S1.

5. A method for designing a pass profile of a horizontal rolling mill according to claim 4, Features: The step S4 is specifically as follows: The order of the 6 hole types used is determined as follows: diamond hole type-flat box hole type-vertical box hole type-flat box hole type-vertical box hole type-flat box hole type. According to the formula F n-1 =F n *μ n Calculate the area of ​​each pass, and then according to F 1 Determine the side length a of the rhombus hole, then the dimensions of each part of the rhombus hole in the first pass are: Side length The composition height of the hole type h = (1.4 ~ 1.41)a; The width of the hole is b = (1.41-1.42) a; The height of the hole is Hk = (1.4 ~ 1.41)a-0.828R; The width of the pass Bk = (1.41-1.42)as, where s is the roll gap value, s = (0.02-0.03)D, and D is the roll diameter; Inner fillet radius R = (0.1 ~ 0.2)h; Outer fillet radius r = (0.05-0.1)h; The dimensions of each part of the second pass flat box pass are: The width of the box Bk 1 =a+△b 1 , the height of the box Hk 1 =a-△h 1 , where △b 1 is the first widening margin, with a value range of 5-15mm; △h 1 is the first pressing amount, the value range is 10-25mm; B 1 =Bk 1 -y(Hk 1 -s), where y is the slope of the side wall of the hole, ranging from 5% to 20%; B1 is the groove bottom width of the second pass flat box hole; Inner corner radius R 1 =(0.1~0.2)h 1 ; Outer corner radius r 1 =(0.05-0.1)h 1 ; The dimensions of each part of the third pass box pass are: The width of the box Bk 2 =Hk 1 +△b 2 , the height of the box Hk 2 =Bk 1 -△h 2 , where △b 2 is the second widening margin, with a value range of 5-15mm; △h 2 is the second pressing amount, the value range is 10-25mm; B 2 =Bk 2 -y(Hk 2 -s), where B2 is the bottom width of the third pass of the vertical box hole; Inner corner radius R 2 =(0.1~0.2)h 2 ; Outer corner radius r 2 =(0.05-0.1)h 2 ; According to the above method, the dimensions of the flat box hole profile of the fourth pass, the vertical box hole profile of the fifth pass and the flat box hole profile of the sixth pass are calculated in sequence.

6. A method for designing a pass profile of a horizontal rolling mill according to claim 5, Features: The step S5 specifically includes: preliminarily drawing drawings of each hole type, calculating the cross-sectional area of ​​each pass according to each hole type drawing, revising the hole type parameters by comparing with the theoretical values ​​of step S3, and calculating the deformation of each pass.

7. A method for designing a pass profile of a horizontal rolling mill according to claim 6, Features: The method for calculating whether the process requirements are met according to the deformation amount of each pass in step S6 is: ε n =(F (n-1) -F n ) / F (n-1) ≤20%, where ε is the deformation; The method for calculating whether the bite condition is met is specifically as follows: according to the natural bite condition of the rolled piece, the relationship between the friction angle when the roller contacts the rolled piece and the bite angle is determined, and when β>ɑ, the rolled piece can be naturally bitten, wherein β is the friction angle when the roller contacts the rolled piece; ɑ is the bite angle; The method for calculating whether the deformation amount of each pass meets the requirements when the roll gap changes is specifically: calculating the area of ​​each pass when the roll gap is at the maximum and minimum, and calculating whether the deformation amount of each pass is within the process requirement range.

Images