Methods for designing roll pass profiles for reversible rolling mills of high-temperature alloys

Abstract

This invention discloses a method for designing rolling pass profiles for high-temperature alloys using a reversible rolling mill. The method includes selecting a mixed pass profile system of rhomboid, square, elliptical, and round holes; determining the billet size and total elongation coefficient based on the finished product size and total processing rate; determining the total number of rolling passes and the distribution of deformation in each pass using a reverse calculation method based on the finished product specifications and the roll length of the reversible rolling mill; designing corresponding pass profile parameters based on the elongation coefficient of each pass; and verifying and optimizing the design using the Usatovsky method. Finally, verifying the roll arrangement and mill power capacity by combining the roll length, guides, and pass profile dimensions. This invention, through the rational selection of the pass profile system and optimization of pass profile geometry and rolling schedule, achieves multiple passes per pass, controllable and adjustable total number of rolling passes and deformation per pass, reducing grain coarsening caused by repeated intermediate heating, and effectively improving uneven deformation, microstructural defects, and surface quality issues during the rolling of high-temperature alloys.

Description

Technical Field

[0001] This invention belongs to the field of metal processing technology and relates to a method for designing roll pass profiles for high-temperature alloys in a reversible rolling mill. Background Technology

[0002] High-temperature alloys are widely used in the manufacture of key components for aerospace engines, gas turbines, and the nuclear industry due to their excellent high-temperature strength, oxidation resistance, and creep resistance. However, traditional transverse rolling mill processes have the following drawbacks due to their high deformation resistance, poor plasticity, narrow hot working window, and susceptibility to surface cracks and microstructure inhomogeneity:

[0003] (1) Rolling adjustment is difficult, manual labor intensity is high, production efficiency is low, human factors have a large impact, final rolling temperature is difficult to control and performance stability is poor.

[0004] (2) The use of box-shaped hole + elliptical + round hole type results in poor rolling stability and easy to twist, which leads to poor dimensional accuracy of rolled parts.

[0005] (3) The four corners of the box-shaped hole are not deformed enough and the temperature drops quickly during the elongation deformation process, which can easily lead to local grain mixing or coarseness.

[0006] (4) Rolling temperature fluctuations can cause surface cracks or ear defects;

[0007] (5) Traditional box-type hole design is not good at controlling deformation and permeability, and the looseness in the core is difficult to eliminate. Summary of the Invention

[0008] The purpose of this invention is to provide a method for designing the roll pass of a reversible rolling mill for high-temperature alloys, which solves the problems of uneven deformation, numerous structural defects, and poor surface quality in the existing high-temperature alloy rolling process.

[0009] The technical solution adopted in this invention is a method for designing roll pass patterns for high-temperature alloys using a reversible rolling mill. This method includes selecting a mixed roll pass system of rhomboid, square, elliptical, and round holes; determining the billet size and total elongation coefficient based on the finished product size and total processing rate; determining the total number of rolling passes and the distribution of deformation for each pass using a reverse calculation method based on the finished product size and the length of the reversible rolling mill roll body; designing corresponding roll pass parameters based on the elongation coefficient of each pass; verifying and optimizing the parameters using the Usatovsky method; and verifying the roll body layout and rolling mill force capacity based on the roll body length, guides, and roll pass size.

[0010] The blank size and total elongation coefficient are determined based on the finished product size and total processing rate, using the following formula:

[0011] (1)

[0012] (2)

[0013] In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of skin removed, and F0 is the cross-sectional area of ​​the billet. The area of ​​the base circle of the finished product is [area]. This represents the total processing rate.

[0014] Based on the finished product size and the length of the reversible rolling mill rolls, the total number of rolling passes and the distribution of deformation in each pass are determined using a reverse calculation method. The relationship between the rhomboid pass apex angle, the number of passes, and the elongation coefficient is as follows:

[0015] When the apex angle of the rhombic hole is 100°, the elongation coefficient per pass is 1.29–1.38 for 1 hole with 1 pass; 1 hole with 2 passes has an elongation coefficient of 1.20–1.29 per pass and a total elongation coefficient of 1.54–1.65 for 1 hole with 3 passes; 1 hole with 1.18–1.23 per pass and a total elongation coefficient of 1.65–1.83 for 1 hole with 4 passes; and 1.10–1.20 per pass and a total elongation coefficient of 1.64–1.87 for 1 hole with 4 passes.

[0016] When the apex angle of the rhombic hole is 105°, the elongation coefficient per pass is 1.38–1.44 for 1 hole with 1 pass; 1.25–1.36 for 1 hole with 2 passes, and a total elongation coefficient of 1.67–1.77 for 1 hole with 3 passes; 1.22–1.27 for 1 hole with a total elongation coefficient of 1.78–1.91 for 1 hole with 4 passes; and 1.15–1.22 for 1 hole with a total elongation coefficient of 1.90–2.00 for 1 hole with 4 passes.

[0017] When the apex angle of the rhomboid hole is 110°, the elongation coefficient per pass is 1.45–1.53 for 1 hole with 1 pass; 1 hole with 2 passes has an elongation coefficient of 1.34–1.38 per pass and a total elongation coefficient of 1.83–1.89; 1 hole with 3 passes has an elongation coefficient of 1.27–1.33 per pass and a total elongation coefficient of 2.00–2.10; and 1 hole with 4 passes has an elongation coefficient of 1.18–1.27 per pass and a total elongation coefficient of 2.10–2.30.

[0018] In the relationship between the apex angle of the rhombus hole, the number of passes, and the elongation coefficient, the numerical error of the single-pass elongation coefficient and the total elongation coefficient is ±0.05, and the radius of the apex angle of the rhombus hole is ≈0.2~0.25d', where d' is the diameter of the inscribed circle of the rhombus hole.

[0019] The relationship between the apex angle and number of passes of a rhombus-shaped aperture and the elongation coefficient of the aperture behind it is as follows:

[0020] When the apex angle of the rhomboid hole is 100°, the elongation coefficient of the hole type after 1 pass is 1.11 to 1.17, the elongation coefficient of the hole type after 2 passes is 1.13 to 1.19, the elongation coefficient of the hole type after 3 passes is 1.12 to 1.18, and the elongation coefficient of the hole type after 4 passes is 1.10 to 1.16.

[0021] When the apex angle of the rhomboid hole is 105°, the elongation coefficient of the hole type after 1 pass is 1.16 to 1.22, the elongation coefficient of the hole type after 2 passes is 1.15 to 1.21, the elongation coefficient of the hole type after 3 passes is 1.15 to 1.21, and the elongation coefficient of the hole type after 4 passes is 1.12 to 1.18.

[0022] When the apex angle of the rhomboid hole is 110°, the elongation coefficient of the hole type after 1 pass is 1.19 to 1.25, the elongation coefficient of the hole type after 2 passes is 1.17 to 1.23, the elongation coefficient of the hole type after 3 passes is 1.16 to 1.22, and the elongation coefficient of the hole type after 4 passes is 1.13 to 1.19.

[0023] The relationship between the elongation coefficient of elliptical and circular hole types is as follows:

[0024] The square material is fed into an elliptical hole, with an elongation coefficient of 1.27 to 1.68.

[0025] The elongation coefficient of a round bar entering an elliptical hole is 1.22 to 1.58.

[0026] The elliptical material is fed into a round hole, and its elongation coefficient is 1.12 to 1.38.

[0027] Based on the relationship between the apex angle and number of passes of the rhomboid pass and the elongation coefficient of the subsequent pass, as well as the relationship between the elongation coefficients of the elliptical and circular passes, the elongation coefficients of the transition square pass, the finishing elliptical pass, and the finished circular pass are initially determined. m f , m t , m y Calculate the total elongation coefficient of the extended rhomboid aperture. Then through The combination of the hole type and the elongation coefficient is determined by combining the relationship between the apex angle of the rhomboid hole type, the number of passes, and the elongation coefficient.

[0028] The corresponding aperture parameters are designed based on the elongation coefficient of each pass, and then checked and optimized according to the Usatovsky method. The specific steps include:

[0029] Step 3.1, Finished Hole Pattern:

[0030] The finished base circle radius R = 0.5(d + Δ), the expansion angle θ = 30°, and the width B of the finished hole. k =1.02×(d+Δ+0.5), Roll gap S=(0.05~0.3)R, Side angle Expansion radius The outer fillet radius of the hole is r1 = 2~8mm, and the groove depth is h. k =R-0.5×S;

[0031] Step 3.2, Elliptical Hole Type:

[0032] Based on the area of ​​the elliptical bar Therefore, we can conclude that:

[0033] (3)

[0034] In the formula, m y h is the elongation coefficient of the finished circular hole. t For elliptical die rolling, the material height is b t The width of the material is for elliptical die rolling;

[0035] Take the width expansion coefficient of elliptical bar stock in a round hole. β y =0.3~0.55, thus obtaining equation (4):

[0036] (4)

[0037] Substituting equation (3) into equation (4), we obtain equation (5):

[0038] (5)

[0039] The solution yields: b t , h t ;

[0040] Filling degree of elliptical aperture d t =b t / B k' =0.8~0.9, then:

[0041] Elliptical slot width B k' = b t / d t Roll gap S' = (0.05~0.3) h t ; Elliptical hole groove depth h k' =(h t -S') / 2; radius of the arc The outer fillet radius of the hole is r2 = (0.08~0.12)B. k' ;

[0042] Step 3.3, Transition square hole type:

[0043] Transition square hole side length , m t The elongation coefficient of the elliptical hole shape before finishing. To ensure the transition square hole is filled with a cross-sectional area coefficient, the value is taken as 0.95~1.0, and the roll gap S" = (0.05~0.3)a, and the groove width. A vertex angle of 90°, vertex radius R"=(0.12~0.3)a, and groove depth. The outer fillet radius of the hole is r3 = (0.12~0.5)a.

[0044] Step 3.4, diamond-shaped hole:

[0045] Step 3.4.1, transition from square hole to diamond hole.

[0046] Step 3.4.1.1, Hole Design

[0047] bar stock area , m f The elongation coefficient for the transition square hole type. The fill factor for the rhomboid aperture, i.e., the aperture fill factor, ranges from 0.7 to 0.99.

[0048] When the vertex angle β = 100°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6)R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan40°+S4);

[0049] When the vertex angle β = 105°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth h k4 =0.5×B k4 ×tan37.5°-R4(1 / sin52.5°-1), the outer fillet radius of the hole r4=(0.05~0.35)×(B) k4 ×tan37.5°+S4);

[0050] When the vertex angle β = 110°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width The radius of the apex arc R4 = (0.3~0.6) × R1, and the groove depth. The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan35°+S4);

[0051] Step 3.4.1.2, Determining the roll gap S3 for the third pass of the diamond-shaped die:

[0052] (6)

[0053] Step 3.4.1.3, Determining the roll gap S2 for the second pass of the diamond-shaped die:

[0054] (7)

[0055] Step 3.4.1.4, Determining the roll gap S1 for the first pass of the diamond-shaped die:

[0056] (8)

[0057] In the formula, ΔS is the extension coefficient for the i-th pass of the rhombic aperture type, where i = 1, 2, 3, 4. 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass.

[0058] Step 3.4.2, transition from square hole to diamond hole;

[0059] According to step 3.4.1, first calculate the cross-sectional area of ​​the last pass of the die based on the previously allocated deformation amount, and then calculate the relevant parameters of the die and the roll gap value of each pass of the die.

[0060] The roller body is made of cloth, and the roller ring width is ≥1.0H, where H is the groove depth. For elliptical materials entering the round hole, rolling guides are used, and the width of the roller rings on both sides is ≥1.0. F d , F d The diameter of the circular hole in this pass is the diameter of the finished circular holes, which are arranged continuously and on both sides of the other hole types.

[0061] The rolling force was checked for maximum deformation using engineering methods:

[0062] (9)

[0063] In the formula, P is the rolling force, B is the feed width, b is the discharge width, and R is the discharge width. g For the working roll radius, Δ h For the amount of reduction, For the average unit pressure, d x This is the increment (differential) of the deformation zone along the rolling direction. l The length of the deformation zone.

[0064] The beneficial effects of this invention are that it provides a pass design method that adapts to the working characteristics of reversible rolling mills and takes into account the properties of high-temperature alloy materials. By rationally selecting a system of rhomboid, square, elliptical, and circular pass types and optimizing pass geometry parameters (apex angle, radius of curvature) and rolling schedule, it achieves multiple passes per pass, controllable and adjustable total number of rolling passes and deformation per pass. This reduces the number of extended passes, lowers the difficulty of roll placement due to the limited roll length of reversible rolling mills, reduces grain coarsening caused by repeated intermediate heating, and effectively improves uneven deformation, microstructural defects, and surface quality issues during the rolling of high-temperature alloys. The invention addresses several key issues. It effectively improves upon the limitations of traditional transverse rolling mills in high-temperature alloy rolling, which previously suffered from difficult rolling adjustments, high labor intensity, low production efficiency, significant human-induced factors, difficulty in controlling final rolling temperature, and poor performance stability. Defects such as dimensional instability, excessive roundness, excessive diameter, and burrs are significantly reduced. It avoids the problems of insufficient deformation at the four corners and rapid temperature drop during the box-type die extension deformation process, which easily leads to localized grain mixing or coarseness. Furthermore, it eliminates the insufficient control of deformation penetration and core porosity defects inherent in traditional box-type die designs, thereby improving yield, microstructure uniformity, performance consistency, and stability. Attached Figure Description

[0065] Figure 1 This is a diagram showing the rolling passes and roll pattern of GH4169 bars with a specification of Ф95 prepared from Ф180 billets on a Ф650-L1700 rolling mill in Embodiment 5 of the present invention.

[0066] Figure 2 This is a roll pattern diagram of GH4169 bar stock rolls with a roll pass of Ф95 prepared from Ф180 billets of a Ф650-L1700 rolling mill in Embodiment 5 of the present invention.

[0067] Figure 3 This is a diagram showing the rolling passes and roll patterns of GH4169 bars with Ф35 and Ф45 specifications prepared from Ф100 billets on a Ф650-L1700 rolling mill in Embodiment 6 of the present invention.

[0068] Figure 4This is a diagram showing the rolling passes and roll pattern of GH4169 bars with a specification of Ф40 prepared from a Ф100 billet on a Ф650-L1700 rolling mill in Embodiment 6 of the present invention.

[0069] Figure 5 This is a roll pattern diagram of GH4169 bar stock with roll pass design for Ф35, Ф40, and Ф45 billets prepared by the Ф650-L1700 rolling mill in Embodiment 6 of the present invention. Detailed Implementation

[0070] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0071] Example 1

[0072] A method for designing roll pass profiles for high-temperature alloys using a reversible rolling mill includes selecting a mixed roll pass profile system of rhomboid, square, elliptical, and round holes; determining the billet size and total elongation coefficient based on the finished product size and total processing rate; determining the total number of rolling passes and the distribution of deformation for each pass using a reverse calculation method based on the finished product size and the length of the reversible rolling mill roll body; designing corresponding roll pass parameters based on the elongation coefficient of each pass; verifying and optimizing the parameters using the Usatovsky method; and verifying the roll body layout and rolling mill force capacity based on the roll body length, guides, and roll pass size.

[0073] Example 2

[0074] A method for designing a roll pass for rolling high-temperature alloys using a reversible rolling mill includes the following steps:

[0075] Step 1: Select a mixed hole pattern system consisting of diamond-shaped holes, square holes, elliptical holes, and round holes;

[0076] Considering the characteristics of a two-roll reversible mill, a rhomboid die with good bite, high rolling stability, deep deformation, sufficient and controllable edge deformation, and the ability to roll multiple passes in one pass is adopted to replace the traditional box-shaped die with poor stability, difficult adjustment, insufficient control of deformation penetration, small edge deformation and large temperature drop, which easily leads to local grain mixing or coarse box-shaped extension. After the square die transition, the finishing die adopts an elliptical + round die with good deformation uniformity, uniform temperature drop, high surface quality and controllable finished product size.

[0077] Step 2: Determining the billet size, total number of passes, and allocating the deformation amount per pass;

[0078] Step 2.1: Determine the blank size and total elongation coefficient based on the finished product size and total processing rate. The calculation formula is as follows:

[0079] (1)

[0080] (2)

[0081] In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of peeling, and F0 is the cross-sectional area of ​​the billet (i.e., the cross-sectional area of ​​the billet). It is the cross-sectional area of ​​the base circle of the finished product (i.e., the cross-sectional area of ​​the finished product before peeling). This represents the total processing rate.

[0082] Step 2.2: Based on the finished product specifications and the length of the reversible rolling mill rolls, the total number of rolling passes and the distribution of deformation in each pass are determined by a reverse calculation method.

[0083] Because a mixed pass profile and multi-pass rolling process are used, the average elongation coefficient cannot be set based on empirical data for the total number of rolling passes. According to n=log / log Calculate the required number of passes. Therefore, this invention employs a reverse calculation method based on product specifications and the finite length of the reversible rolling mill rolls;

[0084] Step 3: Design the corresponding aperture parameters based on the elongation coefficients of each pass determined in Step 2, and verify and optimize them according to the Usatovsky method.

[0085] Step 4: Arrange the rollers according to the roller body length, guide, and die size (if roller arrangement is not possible, adjust the process and die parameters). The roller ring width should be ≥1.0H, where H is the groove depth. For elliptical materials entering the round die, use rolling guides with roller ring widths ≥1.0 on both sides. F d , F d The diameter of the circular hole in this pass is the diameter of the finished circular holes, which are arranged continuously and on both sides of the other hole types.

[0086] Step 5: Verify the rolling mill's force parameters, and use engineering methods to verify the rolling force for the maximum deformation.

[0087] Example 3

[0088] A method for designing a roll pass for rolling high-temperature alloys using a reversible rolling mill includes the following steps:

[0089] Step 1: Select a mixed hole pattern system consisting of diamond-shaped holes, square holes, elliptical holes, and round holes;

[0090] Considering the characteristics of a two-roll reversible mill, a rhomboid die with good bite, high rolling stability, deep deformation, sufficient and controllable edge deformation, and the ability to roll multiple passes in one pass is adopted to replace the traditional box-shaped die with poor stability, difficult adjustment, insufficient control of deformation penetration, small edge deformation and large temperature drop, which easily leads to local grain mixing or coarse box-shaped extension. After the square die transition, the finishing die adopts an elliptical + round die with good deformation uniformity, uniform temperature drop, high surface quality and controllable finished product size.

[0091] Step 2: Determining the billet size, total number of passes, and allocating the deformation amount per pass;

[0092] Step 2.1: Determine the blank size and total elongation coefficient based on the finished product size and total processing rate. The calculation formula is as follows:

[0093] (1)

[0094] (2)

[0095] In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of skin removed, and F0 is the cross-sectional area of ​​the billet. The area of ​​the base circle of the finished product is [area]. This represents the total processing rate.

[0096] Step 2.2: Based on the finished product specifications and the length of the reversible rolling mill rolls, the total number of rolling passes and the distribution of deformation in each pass are determined by a reverse calculation method.

[0097] Because a mixed pass profile and multi-pass rolling process are used, the average elongation coefficient cannot be set based on empirical data for the total number of rolling passes. According to n=log / log Calculate the required number of passes. Therefore, this invention uses a reverse calculation method based on the product specifications and the limited length of the reversible rolling mill roll body. Table 1 shows the relationship between the apex angle of the rhomboid pass, the number of passes, and the elongation coefficient; Table 2 shows the relationship between the apex angle of the rhomboid pass, the number of passes, and the elongation coefficient of the passes of the rhomboid pass and the passes of the subsequent passes; Table 3 shows the elongation coefficients of the passes of elliptical and circular passes.

[0098] Table 1. Relationship between the apex angle of the rhomboid aperture, the number of passes, and the elongation coefficient.

[0099]

[0100] In Table 1, the radius of the apex of the rhombus is approximately 0.2~0.25d (diameter of the inscribed circle of the rhombus); the larger value is used when the circle enters the rhombus, and the smaller value is used when the rhombus enters the rhombus; the numerical error in the table is ±0.05.

[0101] Table 2. Relationship between the apex angle and number of passes of a rhombus-shaped aperture and the extension coefficient of the pass number of the aperture behind it.

[0102]

[0103] The numerical error in Table 2 is ±0.03.

[0104] Table 3. Relationship between the elongation coefficient of elliptical and circular hole types.

[0105]

[0106] The numerical error in Table 3 is ±0.03.

[0107] Step 2.2.1: First, determine the elongation coefficient (μ) of the transition square hole type and the precision rolled elliptical and round hole types according to Tables 2 and 3. f μ t μ y );

[0108] Step 2.2.2: Calculate the total elongation coefficient of the extended rhomboid aperture. :

[0109] (3)

[0110] Step 2.2.3, then through The combination of aperture type and pass extension coefficient is determined by referring to Table 1;

[0111] Step 3: Design the corresponding aperture parameters based on the elongation coefficients for each pass determined in Step 2, and verify and optimize them using the Usatovsky method. This specifically includes the following steps:

[0112] Step 3.1, Finished Hole Pattern:

[0113] The finished base circle radius R = 0.5(d + Δ), the expansion angle θ = 30°, and the width B of the finished hole. k =1.02×(d+Δ+0.5), Roll gap S=(0.05~0.3)R, Side angle Expansion radius Outer fillet radius r1 = 2~8mm, groove depth h k =R-0.5×S;

[0114] Step 3.2, Finished product with an elliptical hole shape:

[0115] Based on the area of ​​the elliptical bar Therefore, we can conclude that:

[0116] (4)

[0117] In the formula, m y h is the elongation coefficient of the finished circular hole. t For elliptical die rolling, the material height is b t The width of the material is for elliptical die rolling;

[0118] Take the width expansion coefficient of elliptical bar stock in a round hole. β y =0.3~0.55, thus obtaining equation (5):

[0119] (5)

[0120] Substituting equation (4) into equation (5), we obtain equation (6):

[0121] (6)

[0122] The solution yields: b t , h t ;

[0123] Filling degree of elliptical aperture d t =b t / B k' =0.8~0.9, then:

[0124] Elliptical slot width B k' = b t / d t Roll gap S' = (0.05~0.3) h t ; Elliptical hole groove depth h k' =(h t -S') / 2; radius of the arc The outer fillet radius of the hole is r2 = (0.08~0.12)B. k' ;

[0125] Step 3.3, Transition square hole type:

[0126] Transition square hole side length , m t The elongation coefficient of the elliptical hole shape before finishing. To ensure the transition square hole is filled with a cross-sectional area coefficient, the value is taken as 0.95~1.0, and the roll gap S" = (0.05~0.3)a, and the groove width. A vertex angle of 90°, vertex radius R"=(0.12~0.3)a, and groove depth. The outer fillet radius of the hole is r3 = (0.12~0.5)a;

[0127] Step 3.4, diamond-shaped hole:

[0128] Step 3.4.1, transition from square hole to diamond hole.

[0129] Step 3.4.1.1, Hole Design

[0130] bar stock area , m f The elongation coefficient for the transition square hole type. dl The value is the cross-sectional area coefficient for the rhomboid aperture, i.e. the aperture filling degree, and its value ranges from 0.7 to 0.99.

[0131] When the vertex angle β = 100°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan40°+S4);

[0132] When the vertex angle β = 105°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan37.5°+S4);

[0133] When the vertex angle β = 110°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width The radius of the apex arc R4 = (0.3~0.6) × R1, and the groove depth. The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan35°+S4);

[0134] Step 3.4.1.2, Determining the roll gap S3 for the third pass of the diamond-shaped die:

[0135] (7)

[0136] Step 3.4.1.3, Determining the roll gap S2 for the second pass of the diamond-shaped die:

[0137] (8)

[0138] Step 3.4.1.4, Determining the roll gap S1 for the first pass of the diamond-shaped die:

[0139] (9)

[0140] In the formula, Let ΔS be the elongation coefficient for the i-th pass of the rhombic aperture type, where i = (1, 2, 3, 4). The elongation coefficient values ​​for each pass can be found in Table 1. 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass.

[0141] Step 3.4.2, transition from square hole to diamond hole.

[0142] Following the method in step 3.4.1, first calculate the cross-sectional area of ​​the last pass of the die based on the previously allocated deformation amount, and then calculate the relevant parameters of the die and the roll gap value of each pass of the die.

[0143] The verification and optimization were performed according to the Usatovsky method (also known as the Z. Usatovsky method).

[0144] Step 4: Arrange the rollers according to the roller body length, guide, and die size (if roller arrangement is not possible, adjust the process and die parameters). The roller ring width should be ≥1.0H, where H is the groove depth. For elliptical materials entering the round die, use rolling guides with roller ring widths ≥1.0 on both sides. F d , F d The diameter of the circular hole in this pass is the diameter of the finished circular holes, which are arranged continuously and on both sides of the other hole types.

[0145] Step 5: Verify the rolling mill's force parameters, using engineering methods to verify the rolling force at the maximum deformation:

[0146] (10)

[0147] In the formula, P is the rolling force, B is the feed width, b is the discharge width, and R is the discharge width. g For the working roll diameter, Δ h For the amount of reduction, For the average unit pressure, d x This is the increment (differential) of the deformation zone along the rolling direction. l The length of the deformation zone.

[0148] Example 4

[0149] A method for designing a roll pass for rolling high-temperature alloys using a reversible rolling mill includes the following steps:

[0150] Step 1: Select a mixed hole pattern system consisting of diamond-shaped holes, square holes, elliptical holes, and round holes;

[0151] Considering the characteristics of a two-roll reversible mill, a rhomboid die with good bite, high rolling stability, deep deformation, sufficient and controllable edge deformation, and the ability to roll multiple passes in one pass is adopted to replace the traditional box-shaped die with poor stability, difficult adjustment, insufficient control of deformation penetration, small edge deformation and large temperature drop, which easily leads to local grain mixing or coarse box-shaped extension. After the square die transition, the finishing die adopts an elliptical + round die with good deformation uniformity, uniform temperature drop, high surface quality and controllable finished product size.

[0152] Step 2: Determining the billet size, total number of passes, and allocating the deformation amount per pass;

[0153] Step 2.1: Determine the blank size and total elongation coefficient based on the finished product size and total processing rate. The calculation formula is as follows:

[0154] (1)

[0155] (2)

[0156] In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of skin removed, and F0 is the cross-sectional area of ​​the billet. The area of ​​the base circle of the finished product is [area]. This represents the total processing rate.

[0157] Step 2.2: Based on the finished product specifications and the length of the reversible rolling mill rolls, the total number of rolling passes and the distribution of deformation in each pass are determined by a reverse calculation method.

[0158] Step 2.2.1: First, determine the elongation coefficient (μ) of the transition square hole type and the precision rolled elliptical and round hole types according to Tables 2 and 3. f μ t μ y );

[0159] Step 2.2.2: Calculate the total elongation coefficient of the extended rhomboid aperture. :

[0160] (3)

[0161] Step 2.2.3, then through The combination of aperture type and pass extension coefficient is determined by referring to Table 1;

[0162] Step 3: Design the corresponding aperture parameters based on the elongation coefficients for each pass determined in Step 2, and verify and optimize them using the Usatovsky method. This specifically includes the following steps:

[0163] Step 3.1, Finished Hole Pattern:

[0164] The finished base circle radius R = 0.5(d + Δ), the expansion angle θ = 30°, and the width B of the finished hole. k =1.02×(d+Δ+0.5), Roll gap S=(0.05~0.3)R, Side angle Expansion radius Outer fillet radius r1 = 2~8mm, groove depth h k =R-0.5×S;

[0165] Step 3.2, Finished product with an elliptical hole shape:

[0166] Based on the area of ​​the elliptical bar Therefore, we can conclude that:

[0167] (4)

[0168] In the formula, m y h is the elongation coefficient of the finished circular hole. t For elliptical die rolling, the material height is b t The width of the material is for elliptical die rolling;

[0169] Take the width expansion coefficient β of the elliptical bar material in the round hole. y =0.3~0.55, thus obtaining equation (5):

[0170] (5)

[0171] Substituting equation (4) into equation (5), we obtain equation (6):

[0172] (6)

[0173] The solution yields: b t , h t ;

[0174] Filling degree of elliptical aperture d t =b t / B k' =0.8~0.9, then:

[0175] Elliptical slot width B k' = b t / d t The roll gap S' = (0.05~0.3) h t ; Elliptical hole groove depth h k' =(ht -S') / 2; radius of the arc The outer fillet radius of the hole is r2 = (0.08~0.12)B k' ;

[0176] Step 3.3, Transition square hole type:

[0177] Transition square hole side length , m t The elongation coefficient of the elliptical hole shape before finishing. To ensure the transition square hole is fully filled, the cross-sectional area coefficient is set to 0.95~1.0, and the roll gap S" = (0.05~0.3)a, and the groove width... A vertex angle of 90°, vertex radius R"=(0.12~0.3)a, and groove depth. The outer fillet radius of the hole is r3 = (0.12~0.5)a;

[0178] Step 3.4, diamond-shaped hole:

[0179] Step 3.4.1, transition from square hole to diamond hole.

[0180] Step 3.4.1.1, Hole Design

[0181] bar stock area , m f The elongation coefficient for the transition square hole type. d l The value is the cross-sectional area coefficient for the rhomboid aperture, i.e. the aperture filling degree, and its value ranges from 0.7 to 0.99.

[0182] When the vertex angle β = 100°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan40°+S4);

[0183] When the vertex angle β = 105°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan37.5°+S4);

[0184] When the vertex angle β = 110°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k Groove width The radius of the apex arc R = (0.3~0.6). R1, groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan35°+S4);

[0185] Step 3.4.1.2, Determining the roll gap S3 for the third pass of the diamond-shaped die:

[0186] (7)

[0187] Step 3.4.1.3, Determining the roll gap S2 for the second pass of the diamond-shaped die:

[0188] (8)

[0189] Step 3.4.1.4, Determining the roll gap S1 for the first pass of the diamond-shaped die:

[0190] (9)

[0191] In the formula, ΔS is the extension coefficient for the i-th pass of the rhombic aperture type, where i = (1, 2, 3, 4). 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass.

[0192] Step 3.4.2, transition from square hole to diamond hole.

[0193] Following the method in step 3.4.1, first calculate the cross-sectional area of ​​the last pass of the die based on the previously allocated deformation amount, and then calculate the relevant parameters of the die and the roll gap value of each pass of the die.

[0194] The verification and optimization were performed according to the Usatovsky method (also known as the Z. Usatovsky method).

[0195] Step 4: Arrange the rollers according to the roller body length, guide, and die size (if roller arrangement is not possible, adjust the process and die parameters). The roller ring width should be ≥1.0H, where H is the groove depth. For elliptical materials entering the round die, use rolling guides with roller ring widths ≥1.0 on both sides. F d , F d The diameter of the circular hole in this pass is the diameter of the finished circular holes, which are arranged continuously and on both sides of the other hole types.

[0196] Step 5: Verify the rolling mill's power parameters.

[0197] Example 5

[0198] A method for designing the roll pass for rolling high-temperature alloys using a reversible rolling mill, specifically for designing a Ф650-L1700 rolling mill to produce GH4169 bars with a Ф95 specification, is described below:

[0199] Step 1, Selection of aperture system:

[0200] Because the finished product specification Ф95 is relatively large, considering the roll body is 1700mm, the following type system is selected: diamond hole type + square hole type + elliptical + round hole (one set);

[0201] Step 2: Determining the billet size, total number of passes, and allocating the deformation amount per pass;

[0202] Step 2.1: Determine the blank size based on the finished product dimensions (finished product diameter d=95mm) and the total processing rate, set the peeling allowance Δ to 3mm, and the total processing rate... It is 70%;

[0203] (1)

[0204] The billet diameter D is set to 180 mm;

[0205] Step 2.2, determine the total elongation factor:

[0206] m =F0 / Fi= ( πD 2 / 4) / ( π ( d+ Δ) 2 / 4)= D 2 / ( d+ Δ) 2 =180 2 / 98 2 ≈3.37 (2)

[0207] In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of skin removed, and F0 is the cross-sectional area of ​​the billet. The area of ​​the base circle of the finished product is [area]. This represents the total processing rate.

[0208] Step 2.3, Determination of total number of passes and allocation of pass deformation:

[0209] Considering the large finished product size, to avoid excessive differences in the microstructure between the center and the edge due to temperature rise in the core, a deformation distribution method of small deformation in the earlier passes and large deformation in the later passes is adopted. The following is done using a reverse calculation method:

[0210] Determine the elongation coefficient of the finished Ф98 round hole type according to Table 3. m y = 1.23. Elongation coefficient of elliptical hole before finishing m t = 1.48;

[0211] The elongation coefficient of the transition square hole is determined according to Table 2. m f = 1.15;

[0212] The total elongation coefficient of the rhomboid hole =3.37 / (1.15×1.48×1.23)≈1.610. Considering the small deformation in the first few passes and the odd number of total rolling passes based on the mill layout, a 100° apex angle, 1 hole, 4 passes method is selected according to Table 1; its single-pass elongation coefficient The extension coefficients for each pass are allocated sequentially: m l-1 =1.09、 m l-2 =1.10、 m l-3 =1.16、 m l-4 =1.16.

[0213] Total rolling passes n = 4 (diamond-shaped hole) + 1 (transition square hole) + 1 (elliptical hole) + 1 (round hole) = 7;

[0214] Step 3: Design the corresponding aperture parameters based on the elongation coefficients for each pass determined in Step 2, and verify and optimize them using the Usatovsky method. This specifically includes the following steps:

[0215] Step 3.1, Finished Hole Pattern:

[0216] The radius of the finished base circle R = 0.5(d+Δ) = 0.5(95+3) = 49mm, the expansion angle θ = 30°, and the width of the finished hole B. k=1.02×(d+Δ+0.5)=1.02×(95+3+0.5)=100.47mm, roll gap S=8.0mm, side angle =arctan =20.83°, Expansion radius = = =68.816mm, outer corner radius r1=4.0mm, groove depth h k =R-0.5×S=49-0.5×8=45mm, see hole pattern diagram. Figure 1 K1.

[0217] Step 3.2, forming the front elliptical hole shape:

[0218] Based on the area of ​​the elliptical bar Equation (3) is derived:

[0219] h t = 11812.92 / b t (3)

[0220] In the formula, h t For elliptical die rolling, the material height is b t The width of the material is for elliptical die rolling;

[0221] Based on experience with elliptical bar stock in widening of round holes, take β y = 0.42, yielding equation (4):

[0222] (4)

[0223] Substituting equation (3) into equation (4), we obtain the quadratic equation (5):

[0224] (5)

[0225] The solution yields: b t =140.85mm, h t = 83.86mm;

[0226] Filling degree of elliptical aperture d t = b t / B k' =0.8~0.9, take d t =0.88, then:

[0227] Elliptical slot width B k' =b t / d t = 140.85 / 0.88≈160mm; Roll gap S'=8mm; Elliptical groove depth h k' =(h t -S') / 2=(83.86-8) / 2=37.93mm; radius of arc = ≈103.33mm; outer fillet radius r' = (0.08~0.12)B k' =0.1×160=16mm, see hole pattern diagram. Figure 1 K2.

[0228] Step 3.3, Transition square hole type:

[0229] d f The transition square hole is filled with a cross-sectional area coefficient, the value of which is between 0.95 and 1.0; in this embodiment, it is taken as 0.97; the side length of the transition square hole... = ≈119mm, roll gap S"=(0.05~0.3)a=5.95~35.7, in this embodiment S" is taken as 10mm, groove width ≈1.414×119-10≈158.27mm, apex angle 90°, apex radius R"=(0.12~0.3)a=0.19a=0.19×119≈22.6mm, groove depth ≈69.78mm, outer fillet radius r3= =14.28~59.5, take 30mm, see hole pattern diagram. Figure 1 Medium K3.

[0230] Step 3.4, diamond-shaped hole:

[0231] Step 3.4.1, Design of the transition square hole type before the rhomboid hole type

[0232] d l The fill factor for the rhomboid aperture, i.e., the aperture fill factor, ranges from 0.7 to 0.99. In this embodiment, it is the fourth pass. d l Take 0.99, third pass. d l Take 0.95, second pass. d l Also take 0.95, for the first pass. d l Take 0.9;

[0233] Based on the area of ​​the fourth pass rhomboid bar stock =0.25×π×(95+3) 2 ×1.23×1.48×1.15 / 0.99≈15950.4mm 2 ;

[0234] When the vertex angle β = 100°, its inscribed circle radius =62.67mm, roll gap S4=(0.05~0.2)h k4 = (0.05~0.2)×71.66=3.6~14.3, take 5mm; Groove width =2×62.67 / cos50°-5×tan50°≈189mm, vertex radius R4=(0.3~0.6)×R1=0.4×62.67≈25.0mm, groove depth =0.5×189×tan40°-25×(1 / sin50°-1)=71.66mm, the outer fillet radius of the hole is r4=(0.05~0.35)×(B k4 ×tan40°+S4)=0.1×(189×tan40°+5)≈16mm, see the hole pattern diagram. Figure 1 K4-4.

[0235] Step 3.4.2, determining the diamond-shaped roll gap S3 for the third pass, see [link / reference]. Figure 1 K4-3;

[0236] (6)

[0237] =5 + 15950.4 × (1.16 - 1) / (189 × 0.95)

[0238] ≈19.2mm

[0239] Step 3.4.3, determining the second diamond-shaped roll gap S, see [link / reference]. Figure 1 K4-2;

[0240] (7)

[0241] =19.2+15950.4×1.16(1.16-1) / (189×0.95)

[0242] ≈35.7mm

[0243] Step 3.4.4, determining the first pass diamond-shaped roll gap S, see [link / reference]. Figure 1 K4-1;

[0244] (8)

[0245] =35.7+15950.4×1.16×1.16×(1.1-1) / (189×0.95)

[0246] ≈47.7mm

[0247] In the formula, is the elongation coefficient of the i-th pass of the rhombic hole type. i = (1, 2, 3, 4) Based on Table 1, ΔS is determined. 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass.

[0248] Step 3.5: Perform verification and optimization according to the Z. Usatovsky method. The optimized parameters are shown in Table 4.

[0249] Table 4

[0250]

[0251] The design requirements were met by verification using the Z. Usatovsky method.

[0252] Step 4, Roller body and cloth roller:

[0253] Referring to Table 5, the roller ring width should be ≥1.0H (groove depth). For elliptical materials entering the circular hole, rolling guides should be used, with the roller ring width on both sides ≥1.0Ф. d , F d This refers to the diameter of the circular hole in this pass. The finished circular holes can be arranged continuously (because they are for single use) and are arranged on two sides, separate from other hole types. See the roller diagram. Figure 2 .

[0254] Table 5

[0255]

[0256] Calculations show that there is still 712.2mm of unused space for the 1700mm long roller body, indicating a reasonable layout.

[0257] Step 5, Verification of rolling mill power parameters

[0258] Using engineering methods:

[0259] (9)

[0260] In the formula, P is the rolling force, B is the feed width, b is the discharge width, and R is the discharge width. g For the working roll diameter, Δ h For the amount of reduction, For the average unit pressure, d x This is the increment (differential) of the deformation zone along the rolling direction. l The length of the deformation zone.

[0261] Because the deformation is greatest in the 6th pass of the elliptical roll pass, only the rolling force is checked, using GH4169 high-temperature alloy at 1050℃ and strain rate... =10-1, rheological stress 390 MPa instead working radius of the roll Then the rolling force P6 for the 6th pass is:

[0262] (10)

[0263] Verification revealed that the rolling pass shape and process in this embodiment meet the design requirements.

[0264] Example 6

[0265] A method for designing roll pass profiles for reversible rolling mills to produce GH4169 bars with specifications of Ф35, Ф40, and Ф45 using a Ф650-L1700 rolling mill is disclosed. The specific process is as follows:

[0266] Step 1, Selection of aperture system:

[0267] Because the finished product specifications Ф35, Ф40, and Ф45 are relatively small, considering the roll body is 1700mm, the following type system is selected: diamond-shaped hole + square hole + elliptical + round hole (2 sets); because, The Φ48 finished base circle can be used as a transition circle for the Φ38 finished base circle. Φ(40+3), i.e., the Φ43 specification, is achieved by adjusting the roll gap through the shared use of other roll patterns, except for the finished die type. The Φ38, Φ43, and Φ48 finished base circles include a 3mm peeling allowance because the black skin on the rolled surface is defective and needs to be peeled off.

[0268] Step 2: Determining the billet size, total number of passes, and allocating the deformation amount per pass:

[0269] Step 2.1: Determine the blank size based on the maximum finished product size and the total processing rate, set the peeling amount Δ to 3mm, and the total processing rate... It is 70%;

[0270] (1)

[0271] Considering the commonality of billet materials, D (billet diameter) is set to 100mm;

[0272] Step 2.2, determine the total elongation coefficient μ ;

[0273] m 48 =F0 / Fi= ( πD 2 / 4) / ( π ( d+ Δ) 2 / 4)= D 2 / ( d+ Δ) 2 =100 2 / 48 2 ≈4.34

[0274] m 38 =F0 / Fi= ( πD 2 / 4) / ( π ( d+ Δ) 2 / 4)= D 2 / ( d+ Δ) 2 =100 2 / 38 2 ≈6.9252

[0275] Step 2.3, Determination of total number of passes and allocation of pass deformation:

[0276] Considering the small finished product size, to avoid edge mixing caused by core temperature drop, a method with larger and more uniform deformation per pass is adopted:

[0277] Step 2.3.1: First, calculate the deformation distribution between Φ48 and Φ38 during rolling:

[0278] (2)

[0279] Based on Table 3, the elongation coefficient μ of the Φ38 round hole type in the finished product is determined. y-1 =1.2, then the elongation coefficient μ of the elliptical hole before finishing is... t-1 =1.33;

[0280] Step 2.3.2, determine the distribution of deformation per pass for the Φ48 to transition square hole type part:

[0281] Based on Table 3, the elongation coefficient μ of the Φ48 round hole type in the finished product is determined. y-2 =1.21, its front elliptical hole elongation coefficient μt-2 =1.35;

[0282] The transition square hole type μ is determined according to Table 2. f = 1.16;

[0283] Step 2.3.3, Distribution of deformation amount per pass for the diamond-shaped hole

[0284] Total elongation coefficient of rhomboid aperture Considering the small size of the product and to prevent temperature drop, the number of rolling passes should be minimized. Furthermore, the reversible mill has a finite roll length, and the total number of rolling passes should be odd based on the mill layout. Therefore, according to Table 1, the initial plan is to use 2 passes and 4 rolls for the diamond-shaped hole rolling, with an average elongation coefficient per pass. Considering the large deformation amount used in the first two passes due to high temperature and low resistance, a rhomboid hole shape with a vertex angle β=105° is adopted. Referring to Table 1, the elongation coefficients of this hole shape are distributed sequentially for the two passes as follows: μ l-1 =1.25, μ l-2 =1.26; To improve intermediate rolling stability, the second rhomboid pass uses a rhomboid pass with a vertex angle β=100°. According to Table 1, the elongation coefficients for the two passes of this pass are distributed sequentially as follows: μ l-3 =1.21、μ l-4 =1.20;

[0285] Rolling Φ45:

[0286] Total rolling passes n = 2 (105° diamond-shaped pass) + 2 (100° diamond-shaped pass) + 1 (transition square pass) + 1 (elliptical pass) + 1 (round pass) = 7

[0287] Rolling Φ40, Φ35:

[0288] Total rolling passes n = 2 (105° diamond-shaped pass) + 2 (100° diamond-shaped pass) + 1 (transition square pass) + 1 (elliptical pass) + 1 (round pass) + 1 (elliptical pass) + 1 (round pass) = 9

[0289] Step 3, Hole design and verification:

[0290] Step 3.1, Finished Hole Pattern:

[0291] Step 3.1.1, Φ35 finished hole pattern

[0292] The radius of the finished base circle R = 0.5(d+3) = 0.5 × (35+3) = 19 mm, the expansion angle θ = 30°, and the width of the finished hole B. k =1.012×(d+3+0.5)=1.012×(35+3+0.5)=38.962mm, roll gap S is taken as 4.0mm, side angle =arctan =21.976°, Expansion radius = = =28.97mm, outer fillet radius of hole r1=3.0mm, groove depth h k =R-0.5×S=19-0.5×4=17mm, see hole pattern diagram. Figure 3 K1.

[0293] Step 3.1.2, Φ40 finished hole pattern

[0294] The radius of the finished base circle is R = 0.5(d+3) = 0.5 (40+3)=21.5mm, expansion angle θ=30°, width B of finished hole k =1.012 (d + 3 + 0.5) = 1.012 (40+3+0.5)=44.022mm, roll gap S=6.0mm, side angle =arctan =23.635°, Expansion radius = = =38.154mm, outer corner radius r1=3.0mm, groove depth h k =R-0.5 S = 21.5 - 0.5 6 = 18.5mm, see hole pattern diagram. Figure 4 K1.

[0295] Step 3.1.3, Φ45 finished hole shape

[0296] The radius of the finished base circle is R = 0.5(d+3) = 0.5 (45+3)=24mm, expansion angle θ=30°, width B of finished hole k =1.012 (d + 3 + 0.5) = 1.012 (45+3+0.5)=49.082mm, roll gap S=6.0mm, side angle =arctan =22.6545°, Expansion radius = = =38.03mm, outer fillet radius of hole r1=4.0mm, groove depth h k =R-0.5 S=24-0.5 6 = 21mm, see hole pattern diagram. Figure 3 Medium K3.

[0297] Step 3.2, Elliptical Hole Type:

[0298] Step 3.2.1, Φ35 pre-finished elliptical hole shape:

[0299] Based on the area of ​​the elliptical bar Equation (3) is derived:

[0300] 1732.8 / (3)

[0301] In the formula, h t-1 The height of the material for Φ35 finished product rolled in an elliptical die, b t-1 The width of the material rolled in the elliptical die before the finished product is Φ35;

[0302] Based on experience with elliptical bar stock in the widening of round holes, β is taken as... y =0.53, thus yielding equation (4):

[0303] (4)

[0304] Substituting equation (3) into equation (4), we obtain the quadratic equation (5):

[0305] (5)

[0306] The solution yields: 60.8mm; =28.5mm;

[0307] Filling degree δ of elliptical aperture t-1 =b t-1 / B k'-1 =0.8~0.9, take δ t-1 =0.87, then:

[0308] Elliptical slot width B k'-1 =b t-1 / δ t-1 =60.8 / 0.87≈70mm; Roll gap S'=4mm; Elliptical groove depth h k'-1 =(h t-1 -S') / 2=(28.5-4) / 2=12.25mm; Radius of the arc R'= = =56.13mm; outer fillet radius r2=(0.08~0.12)B k'-1 =0.1×70=7mm, see hole pattern diagram. Figure 3 K2.

[0309] Step 3.2.2, Φ45 pre-finished elliptical hole shape:

[0310] Based on the area of ​​the elliptical bar Equation (6) is derived.

[0311] 2787.84 / (6)

[0312] In the formula, h t-2 The height of the material for Φ45 finished product rolled in an elliptical die, b t-2 The width of the material rolled in the elliptical die before the finished product is Φ45;

[0313] Based on experience with elliptical bar stock in the widening of round holes, β is taken as... y-2 =0.51, thus obtaining equation (7);

[0314] (7)

[0315] Substituting equation (6) into equation (7) yields a quadratic equation (8);

[0316] (8)

[0317] The solution yields: 74.43mm; =37.5mm;

[0318] Filling degree δ of elliptical aperture t-2 =b t-2 / B k'-2 =0.8~0.9, take δ t-2 =0.9, then:

[0319] Elliptical slot width B k'-2 =b t-2 / δ t-2 =74.43 / 0.9≈83mm; Roll gap S'=8mm; Elliptical groove depth h k'-2 =(h t-2 -S') / 2=(37.5-8) / 2=14.75mm; Radius of the arc R'= = =65.76mm; outer fillet radius r2=(0.08~0.12)B k'-2 =0.1×83=8.3mm, see hole pattern diagram. Figure 3 K4.

[0320] The Φ40 finished product front elliptical die can be shared with the Φ35 finished product front elliptical die by adjusting the roll gap.

[0321] Step 3.3, Transition square hole type:

[0322] d fThe transition square hole is filled with a cross-sectional area coefficient, the value of which is between 0.95 and 1.0; in this embodiment, it is taken as 0.97; the side length a5 of the transition square hole = = ≈55.2mm, roll gap S"=(0.05~0.3)a5=2.76~16.56, in this embodiment S"=8mm, groove width =1.414×55.2-8≈70.0mm, apex angle 90°, apex radius R"=(0.12~0.3)a5=0.22×55.2≈12.1mm, groove depth The outer fillet radius of the hole is r3 = (0.12~0.5)a5 = 0.272 × 55.2 ≈ 15.0 mm. See the hole pattern diagram. Figure 3 K5.

[0323] Step 3.4, diamond-shaped hole:

[0324] Step 3.4.1, Design of the second diamond-shaped hole

[0325] d l-4 The fill factor for the rhomboid aperture, i.e., the aperture fill factor, ranges from 0.7 to 0.99. In this embodiment, it is the fourth pass. d l-4 3rd round d l-3 Second round d l-2 and the first lane d l-1 All are taken as 0.95 (the deformation amounts in these passes are relatively small, so all are taken as 0.95);

[0326] Based on the area of ​​the second rhomboid bar in the fourth pass: =0.25×π×(45+3) 2 ×1.21×1.35×1.16 / 0.95=3609.3mm 2 ;

[0327] When the vertex angle β = 100°, its inscribed circle radius =29.81mm, roll gap S4=5m, groove width =2×29.81 / cos50°-5×tan50°≈87mm, apex radius R4=(0.3~0.6)R1=0.6×29.81≈18mm, groove depth h k4 =0.5×B k4×tan40°-R4(1 / sin50°-1)=0.5×87×tan40°-18×(1 / sin50°-1)≈31mm, outer fillet radius r4=(0.05~0.35)×(B k4 ×tan40°+S4)=0.1×(87×tan40°+5)≈8mm, see the hole pattern diagram. Figure 3 K6-2.

[0328] Step 3.4.2 Determining the diamond-shaped roll gap S for the third pass, see [link / reference]. Figure 3 K6-1;

[0329]

[0330] Step 3.4.3, Design of the first diamond-shaped hole

[0331] Based on the area F of the first rhomboid bar in the second pass l-2 = =0.25 =5240.7mm 2 ;

[0332] When the vertex angle β = 105°, its inscribed circle radius R1 = = ≈35.6mm, roll gap S4=(0.05~0.2)h k4 Take S4 = 5mm, groove width =2×35.6 / cos52.5°-5×tan52.5°≈110mm, apex radius R4=(0.3~0.6)×R1=0.5×35.6≈18mm, groove depth h k4 =0.5×B k4 ×tan37.5°-R4(1 / sin52.5°-1)=0.5×110×tan37.5°-18(1 / sin52.5°-1)≈37.5mm, outer fillet radius r4=(0.05~0.35)×(B k4 ×tan37.5°+S4)=0.1×(110×tan37.5°+5)≈9mm, see the hole pattern diagram. Figure 3 K7-2.

[0333] Step 3.4.4, determining the first diamond-shaped roll gap S in the first pass, see [link / reference]. Figure 3 K7-1;

[0334]

[0335] In the formula, ΔS is the extension coefficient for the i-th pass of the rhombic aperture type, where i = (1, 2, 3, 4). 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass.

[0336] Step 3.5 Perform verification and optimization according to the Z. Usatovsky method.

[0337] Step 3.5.1, Φ45 and Φ35 rolling pass shape and process verification and optimization, the optimized parameters are shown in Table 6:

[0338] Table 6

[0339]

[0340] For rolling process and roll pattern, see Figure 3 ;

[0341] Step 3.5.2, Φ40 rolling pass shape and process verification and optimization, the optimized parameters are shown in Table 7:

[0342] Table 7

[0343]

[0344] For rolling process and roll pattern, see Figure 4 ;

[0345] The design requirements were met by verification using the Z. Usatovsky method.

[0346] Step 4, Roller body and cloth roller:

[0347] Refer to Table 8. The roller ring width is 1.0H (groove depth). For elliptical material entering the circular hole, rolling guides are used. The finished circular holes can be arranged continuously (because they are for single use) and are arranged on two sides, separate from other hole types. See the cloth roller for details. Figure 5 .

[0348] Table 8

[0349]

[0350] Calculations show that 633mm of the 1700mm long roll body is still empty. The multi-pass rolling in one hole can save roll space and leave more room for subsequent new product specifications, indicating that the layout is reasonable.

[0351] Step 5, Verification of rolling mill power parameters

[0352] Using engineering methods:

[0353] (9)

[0354] In the formula, P is the rolling force, B is the feed width, b is the discharge width, and R is the discharge width. g For the working roll diameter, Δ h For the amount of reduction, For the average unit pressure, d x This is the increment (differential) of the deformation zone along the rolling direction. l The length of the deformation zone.

[0355] Because the deformation in the second pass of the diamond-shaped rolling mill is relatively large, only the rolling force is checked, using GH4169 high-temperature alloy at 1000℃ and strain rate. =10 -1 , Rheological stress 450 MPa replaced Working radius R of diamond-shaped hole roll g =325+S- mm, then the rolling force P2 for the second pass is:

[0356] (10)

[0357] Verification revealed that the rolling pass shape and process in this embodiment meet the design requirements.

Claims

1. A method for designing the roll pass for rolling high-temperature alloys using a reversible rolling mill, characterized in that, This includes selecting a mixed pass system of diamond, square, elliptical, and round holes; determining the billet size and total elongation coefficient based on the finished product size and total processing rate; determining the total number of rolling passes and the distribution of deformation in each pass using a reverse calculation method based on the finished product size and the length of the reversible mill roll body; designing corresponding pass parameters based on the elongation coefficient of each pass; verifying and optimizing the parameters using the Usatovsky method; and verifying the roll body layout and mill force capacity based on the roll body length, guides, and pass size. The blank size and total elongation coefficient are determined based on the finished product size and total processing rate, using the following formula: （1） （2） In the formula, D is the diameter of the billet. d is the total elongation coefficient, d is the finished product diameter, Δ is the amount of skin removed, and F0 is the cross-sectional area of ​​the billet. The area of ​​the base circle of the finished product is [area]. Total processing rate; Based on the finished product specifications and the length of the reversible rolling mill rolls, the total number of rolling passes and the distribution of deformation in each pass are determined using a reverse calculation method. The relationship between the rhomboid pass apex angle, the number of passes, and the elongation coefficient is as follows: When the apex angle of the rhombic hole is 100°, the elongation coefficient per pass is 1.29–1.38 for 1 hole with 1 pass; 1 hole with 2 passes has an elongation coefficient of 1.20–1.29 per pass and a total elongation coefficient of 1.54–1.65 for 1 hole with 3 passes; 1 hole with 1.18–1.23 per pass and a total elongation coefficient of 1.65–1.83 for 1 hole with 4 passes; and 1.10–1.20 per pass and a total elongation coefficient of 1.64–1.87 for 1 hole with 4 passes. When the apex angle of the rhombic hole is 105°, the elongation coefficient per pass is 1.38–1.44 for 1 hole with 1 pass; 1.25–1.36 for 1 hole with 2 passes, and a total elongation coefficient of 1.67–1.77 for 1 hole with 3 passes; 1.22–1.27 for 1 hole with a total elongation coefficient of 1.78–1.91 for 1 hole with 4 passes; and 1.15–1.22 for 1 hole with a total elongation coefficient of 1.90–2.00 for 1 hole with 4 passes. When the apex angle of the rhombic hole is 110°, the elongation coefficient per pass is 1.45–1.53 for 1 hole with 1 pass; 1.34–1.38 for 1 hole with 2 passes, and a total elongation coefficient of 1.83–1.89 for 1 hole with 3 passes; 1.27–1.33 for 1 hole with a total elongation coefficient of 2.00–2.10 for 1 hole with 4 passes; and 1.18–1.27 for 1 hole with a total elongation coefficient of 2.10–2.30 for 1 hole with 4 passes. In the relationship between the apex angle of the rhombus-shaped hole, the number of passes, and the elongation coefficient, the numerical error of the single-pass elongation coefficient and the total elongation coefficient is ±0.05, and the radius of the apex angle of the rhombus-shaped hole is ≈0.2~0.25d', where d' is the diameter of the inscribed circle of the rhombus-shaped hole; The relationship between the apex angle and number of passes of the rhomboid aperture and the elongation coefficient of the aperture behind it is as follows: When the apex angle of the rhomboid hole is 100°, the elongation coefficient of the hole type after 1 pass is 1.11 to 1.17, the elongation coefficient of the hole type after 2 passes is 1.13 to 1.19, the elongation coefficient of the hole type after 3 passes is 1.12 to 1.18, and the elongation coefficient of the hole type after 4 passes is 1.10 to 1.

16. When the apex angle of the rhomboid hole is 105°, the elongation coefficient of the hole type after 1 pass is 1.16 to 1.22, the elongation coefficient of the hole type after 2 passes is 1.15 to 1.21, the elongation coefficient of the hole type after 3 passes is 1.15 to 1.21, and the elongation coefficient of the hole type after 4 passes is 1.12 to 1.

18. When the apex angle of the rhomboid hole is 110°, the elongation coefficient of the hole type after 1 pass is 1.19 to 1.25, the elongation coefficient of the hole type after 2 passes is 1.17 to 1.23, the elongation coefficient of the hole type after 3 passes is 1.16 to 1.22, and the elongation coefficient of the hole type after 4 passes is 1.13 to 1.

19.

2. The method for designing the roll pass for high-temperature alloy rolling using a reversible rolling mill according to claim 1, characterized in that, The relationship between the elongation coefficient of elliptical and circular hole types is as follows: The square material is fed into an elliptical hole, with an elongation coefficient of 1.27 to 1.

68. The elongation coefficient of a round bar entering an elliptical hole is 1.22 to 1.

58. The elliptical material is fed into a round hole, and its elongation coefficient is 1.12 to 1.

38.

3. The method for designing the roll pass for reversible rolling mills of high-temperature alloys according to claim 2, characterized in that, Based on the relationship between the apex angle and pass number of the rhomboid pass and the elongation coefficient of the subsequent pass, as well as the relationship between the pass elongation coefficients of the elliptical and circular passes, the elongation coefficients of the transition square pass, the finishing elliptical pass, and the finished circular pass are initially determined. μ f , μ t , μ y Calculate the total elongation coefficient of the extended rhomboid aperture. Then through The combination of the hole type and the elongation coefficient is determined by combining the relationship between the apex angle of the rhomboid hole type, the number of passes, and the elongation coefficient.

4. The method for designing the roll pass for high-temperature alloy rolling using a reversible rolling mill according to claim 1, characterized in that, The corresponding aperture parameters are designed based on the elongation coefficient of each pass, and then checked and optimized according to the Usatovsky method. The specific steps include: Step 3.1, Finished Hole Pattern: The finished base circle radius R = 0.5(d + Δ), the expansion angle θ = 30°, and the width B of the finished hole. k =1.02×(d+Δ+0.5), Roll gap S=(0.05~0.3)R, Side angle Expansion radius The outer fillet radius of the hole is r1 = 2~8mm, and the groove depth is h. k =R-0.5×S; Step 3.2, Elliptical Hole Type: Based on the area of ​​the elliptical bar Therefore, we can conclude that: （3） In the formula, μ y h is the elongation coefficient of the finished circular hole. t For elliptical die rolling, the material height is b. t The width of the material is for elliptical die rolling; Take the width expansion coefficient of elliptical bar stock in a round hole. β y =0.3~0.55, thus obtaining equation (4): （4） Substituting equation (3) into equation (4), we obtain equation (5): （5） The solution yields: b t , h t ; Filling degree of elliptical aperture δ t =b t / B k' =0.8~0.9, then: Elliptical slot width B k' = b t / δ t Roll gap S' = (0.05~0.3) h t ; Elliptical hole groove depth h k' =(h t -S') / 2; radius of the arc The outer fillet radius of the hole is r2 = (0.08~0.12)B. k' ; Step 3.3, Transition square hole type: Transition square hole side length , μ t The elongation coefficient of the elliptical hole shape before finishing. To ensure the transition square hole is filled with a cross-sectional area coefficient, the value is taken as 0.95~1.0, and the roll gap S" = (0.05~0.3)a, and the groove width. A vertex angle of 90°, vertex radius R" = (0.12~0.3)a, and groove depth. The outer fillet radius of the hole is r3 = (0.12~0.5)a; Step 3.4, diamond-shaped hole: Step 3.4.1, transition from square hole to diamond hole. Step 3.4.1.1, Hole Design bar stock area , μ f The elongation coefficient for the transition square hole type. The fill factor for the rhomboid aperture, i.e., the aperture fill factor, ranges from 0.7 to 0.

99. When the vertex angle β = 100°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6)R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan40°+S4); When the vertex angle β = 105°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width 1. Corner radius R4 = (0.3~0.6) × R1; 2. Groove depth The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan37.5°+S4); When the vertex angle β = 110°, its inscribed circle radius Roll gap S4 = (0.05~0.2)h k4 Groove width The radius of the apex arc R4 = (0.3~0.6) × R1, and the groove depth. The outer fillet radius of the hole is r4 = (0.05~0.35) × (B) k4 ×tan35°+S4); Step 3.4.1.2, Determining the roll gap S3 for the third pass of the diamond-shaped die: （6） Step 3.4.1.3, Determining the roll gap S2 for the second pass of the diamond-shaped die: （7） Step 3.4.1.4, Determining the roll gap S1 for the first pass of the diamond-shaped die: （8） In the formula, ΔS is the extension coefficient for the i-th pass of the rhombic aperture type, where i = 1, 2, 3, 4. 1-2 ΔS represents the difference between the cross-sectional area S1 of the workpiece after the first pass of the diamond-shaped hole rolling process and the cross-sectional area S2 of the workpiece after the second pass. 2-3 ΔS represents the difference between the cross-sectional area S2 of the workpiece after the second pass of the diamond-shaped hole rolling process and the cross-sectional area S3 of the workpiece after the third pass. 3-4 This represents the difference between the cross-sectional area S3 of the workpiece after the third pass of the diamond-shaped hole rolling process and the cross-sectional area S4 of the workpiece after the fourth pass. Step 3.4.2, transition from square hole to diamond hole. According to step 3.4.1, first calculate the cross-sectional area of ​​the last pass of the die based on the previously allocated deformation amount, and then calculate the relevant parameters of the die and the roll gap value of each pass of the die.

5. The method for designing the roll pass for reversible rolling mills of high-temperature alloys according to claim 4, characterized in that, The roller body has a roller ring width of ≥1.0H, where H is the groove depth. For elliptical materials fed into the circular hole, rolling guides are used, with roller ring widths on both sides ≥1.0Ф. d Ф d The diameter of the circular hole in this pass is the diameter of the finished circular holes, which are arranged continuously and on both sides of the other hole types.

6. The method for designing the roll pass for high-temperature alloy rolling on a reversible rolling mill according to claim 5, characterized in that, The rolling force was checked for maximum deformation using engineering methods: （9） In the formula, P is the rolling force, B is the feed width, b is the discharge width, and R is the discharge width. g For the working roll radius, Δ h For the amount of reduction, Let dx be the average unit pressure, and dx be the increment of the deformation zone along the rolling direction. l The length of the deformation zone.

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