Numerical simulation method for three-roll rolling of small-diameter superalloy pipe
Numerical simulation of three-roll rolling of small-diameter high-temperature alloy tubes was performed using ABAQUS finite element software, which solved the problem of existing process optimization relying on trial and error, and achieved accurate prediction of the rolling process and improved finished product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN DONGAN ELECTROMECHANICAL MFG CO LTD
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-29
AI Technical Summary
The optimization of existing three-roll rolling processes for small-diameter high-temperature alloy tubes relies on trial and error, resulting in long development cycles, high costs, and limited optimization accuracy. It is also difficult to predict the stress-strain distribution and metal flow trajectory during the rolling process.
Numerical simulation was performed using ABAQUS finite element software. Through precise component modeling, material property matching, mesh generation, constraint and contact settings, and post-processing analysis, the macroscopic deformation, triaxial stress, and residual stress of the billet during the rolling process were predicted, and the rolling parameters were optimized.
It enables precise prediction of the rolling process, reduces trial and error costs, shortens the R&D cycle, and improves the dimensional accuracy and internal quality of the finished pipe.
Smart Images
Figure CN122113353A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of interdisciplinary technology of agricultural ecology and climate change, and in particular to a numerical simulation method for three-roll rolling of small-diameter high-temperature alloy pipes. Background Technology
[0002] Small-diameter pipes (typically referring to outer diameters of Φ5-20mm and wall thicknesses of 1-5mm) are indispensable in high-end manufacturing fields such as aerospace, petrochemicals, and nuclear power equipment due to their compact structure and high strength-to-density ratio. Nickel-based high-temperature alloy small-diameter pipes, especially GH3625, are widely used in key components such as aero-engine fuel lines, corrosion-resistant pipes for chemical reactors, and cooling system conduits for nuclear power plants due to their excellent high-temperature strength, corrosion resistance, and fatigue resistance. These pipes have extremely high requirements for dimensional accuracy and internal quality (such as residual stress and crack defects), and their forming quality directly determines the reliability and service life of the final equipment.
[0003] Three-roll rolling is the core process for forming small-diameter tubes. By using three rolls arranged symmetrically at 120°, uniform plastic deformation of the metal material can be achieved, and the roundness of the tube is easier to control compared to two-roll rolling. However, due to the small diameter-to-wall ratio and fine geometric dimensions of small-diameter tubes, and the high high-temperature strength and strong resistance to plastic deformation of GH3625 alloy, the metal flow pattern during rolling is complex, which can easily lead to problems such as excessive wall thickness deviation, excessive ellipticity, and residual stress concentration, resulting in a low yield of finished products.
[0004] Currently, the optimization of three-roll rolling processes for small-diameter pipes mainly relies on trial and error. This involves conducting trial rolling operations by repeatedly adjusting parameters such as rolling speed, pass reduction, and roll gap, and then refining the process based on the results of finished product inspection. This approach has three significant drawbacks: First, the development cycle is long; optimizing the process for a single pipe specification often requires 3-5 trial rolling operations, taking 1-2 months. Second, production costs are high; the cumulative costs of pipe material loss, equipment energy consumption, and labor during trial rolling are substantial, especially given the high price of GH3625 alloy raw materials, which further amplifies the trial and error costs. Third, the optimization accuracy is limited; it cannot predict the microscopic characteristics of stress-strain distribution and metal flow trajectory during the rolling process, making it difficult to address forming defects at their root.
[0005] With the development of computer simulation technology, numerical simulation has become an important means of optimizing tube rolling process. Among them, finite element software such as ABAQUS is widely used in metal plastic forming simulation due to its powerful nonlinear analysis capabilities. Summary of the Invention
[0006] The purpose of this invention is to provide a numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes. Through precise component modeling, material property matching, mesh generation, constraint and contact settings, and post-processing analysis, the method can accurately predict the macroscopic deformation, triaxial stress, residual stress, and rolling force of the tube blank during the rolling process, thereby reducing trial and error costs, shortening the R&D cycle, and improving the dimensional accuracy and internal quality of the finished tube.
[0007] This invention provides a numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes, comprising the following steps: Step S1: Based on the structural dimensions of the roll, billet, pusher block and mandrel to be simulated, use the ABAQUS modeling function to establish the corresponding three-dimensional structural parts. The roll size is consistent with the roll used in the rolling test, and the mandrel diameter is equal to the inner diameter of the billet. Step S2: Assign material properties to each component in the ABAQUS property module. For the tube blank, GH3625 high-temperature alloy is selected. The engineering stress-strain curve is obtained through metal tensile test, converted into true stress and true plastic strain, and then input. Step S3: Position each component in the ABAQUS assembly module to form a complete rolling system assembly with three rolls symmetrically distributed at 120 degrees. Step S4: Perform mesh generation, defining the minimum mesh unit size and unit type for each component; Step S5: Create a display kinetic analysis step, and set the analysis time, mass scaling, and output parameters; Step S6: Create interactions, constrain the rolls, push blocks, and mandrels as rigid bodies, and define the contact relationship between the billet and the rolls and mandrels; Step S7: Develop a motion trajectory parameter App based on Matlab to calculate the axial, radial, and rotary rolling motion trajectories of the roll and the motion trajectory of the pusher block; Step S8: Apply boundary conditions based on the trajectory parameters generated by Matlab; Step S9: Create a double-precision job and solve it; Step S10: Post-process and analyze the simulation results to verify accuracy.
[0008] Preferably, in step S2, the metal tensile test is performed according to GB / T228.1-2021 standard, using three GH3625 specimens from the same batch. The formula for converting true stress to true plastic strain is as follows: ; in, For actual stress, For engineering stress, For engineering contingency, This represents true plastic strain.
[0009] Preferably, in step S4, the minimum grid unit size of the tube blank is 0.05 mm, and the unit type is C3D8R; the minimum grid unit size of the roll is 0.05 mm, the mandrel is 0.04 mm, and the pusher is 0.02 mm, and the unit type of all three is R3D4.
[0010] Preferably, in step S5, the field output interval is 64, outputting variables such as stress, strain, and displacement; the history output interval is 200, outputting energy variables.
[0011] Preferably, in step S6, the contact type between the billet and the roll and the mandrel is surface-to-surface contact, with friction coefficients of 0.1 and 0.01, respectively, and the constraint reference point is the geometric center point of each rigid body.
[0012] Preferably, in step S7, the actual distance the rolling mill travels on the billet is as shown in the following formula: ; in, This represents the actual distance the roll travels on the billet. This is the total length of the rolling surface of the rolling slide. This refers to the working diameter at the contact point between the roll and the billet. This refers to the diameter of the roll shoulder at the point where the roll contacts the slideway.
[0013] Preferably, in step S7, the remaining reduction amount ΔH at the initial position of the roll is calculated using the gap angle A, the opening angle B of the finished tube, the supplementary angle C, and the auxiliary angle E, and an additional 0.05mm allowance is added.
[0014] Preferably, in step S8, the rolls are subjected to radial, axial, and circumferential displacements, the pusher is subjected to displacements along the billet feeding direction, and the mandrel remains stationary.
[0015] Preferably, in step S9, the operation uses double-precision calculation, and the output precision of the node variables is set to full.
[0016] Preferably, in step S10, the residual stress and plastic deformation cloud map are viewed through ABAQUS post-processing, the rolling force data of the geometric center point of the roll is extracted, and the data is compared and verified with the experimental data.
[0017] Therefore, this invention adopts the above-mentioned numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes. Through precise component modeling, material property matching, mesh generation, constraint and contact settings, and post-processing analysis, it achieves accurate prediction of the macroscopic deformation, triaxial stress, residual stress, and rolling force of the tube blank during the rolling process, reducing trial and error costs, shortening the R&D cycle, and improving the dimensional accuracy and internal quality of the finished tube.
[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall process of the numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to the present invention; Figure 2 This is a schematic diagram showing the angles A, B, C, and E corresponding to the relative positions of the billet and the rolling mill in the numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to the present invention. Figure 3 This is a displacement curve applied to the rolling simulation model in the numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes of the present invention. Figure 4 This is a residual stress cloud diagram of the tube blank after rolling in a numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to the present invention. Figure 5 This is a line graph showing the outer radius distribution of the tube blank after rolling in the numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to the present invention. Detailed Implementation
[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0021] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0022] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0023] Example 1 like Figures 1-5 As shown, the present invention provides a numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes, comprising the following steps: Step S1: Based on the structural dimensions of the roll, tube blank, pusher block and mandrel to be simulated, use the ABAQUS modeling function to establish the corresponding three-dimensional structural parts. The roll size is consistent with the roll used in the rolling test, and the mandrel diameter is equal to the inner diameter of the tube blank.
[0024] Enter the Part module of ABAQUS and use the modeling function to create three-dimensional structural components. Set the billet as a three-dimensional solid component, and set the roll, pusher block and mandrel as three-dimensional discrete rigid body components to ensure that the geometry of each component is consistent with the actual structure.
[0025] Step S2: Assign material properties to each component in the ABAQUS properties module. The tube blank is made of GH3625 high-temperature alloy. Compared to traditional steel, the material properties of GH3625 high-temperature alloy are highly sensitive to the heat treatment and rolling process of the tube. Therefore, due to differences in heat treatment and rolling processes among different batches of GH3625 alloy tubes, their elastic modulus and yield strength will exhibit significant dispersion. Therefore, it is necessary to accurately obtain the actual material parameters of the tube through metal tensile testing to provide reliable support for subsequent analysis. The engineering stress-strain curve is obtained through metal tensile testing, converted into true stress and true plastic strain, and then input.
[0026] In step S2, the tensile test of the metal is performed according to GB / T228.1-2021 standard, using three GH3625 specimens from the same batch. The conversion formula between true stress and true plastic strain is shown below: ; in, For actual stress, For engineering stress, For engineering contingency, This represents true plastic strain.
[0027] Step S3: Position each component in the ABAQUS assembly module to form a complete rolling system assembly with three rolls symmetrically distributed at 120 degrees.
[0028] In the "assembly" module, adjust the positional relationship of each component: the three rolls are symmetrically distributed at 120°, the billet is placed in the central area of the three rolls, the mandrel is inserted into the interior of the billet, and the pusher block fits against the end of the billet to form a complete rolling system assembly.
[0029] Step S4: In the "mesh" module, perform mesh generation and define the minimum mesh unit size and unit type for each component.
[0030] In step S4, the minimum grid unit size of the tube blank is 0.05 mm, and the unit type is C3D8R; the minimum grid unit size of the roll is 0.05 mm, the mandrel is 0.04 mm, and the pusher is 0.02 mm, and the unit type of all three is R3D4.
[0031] Step S5: In the “step” module, create a display kinetic analysis step for the rolling process, and set the analysis time, mass scaling and output parameters.
[0032] In step S5, a field output is created, which outputs stress, strain, displacement, velocity, acceleration, action and reaction forces, contact and volume coordinate variables. The scope is the entire model, the frequency is a uniform time interval, the field output interval is 64, and the output variables such as stress, strain and displacement are output; the history output interval is 200, and the energy variable is output.
[0033] Step S6: Create interactions in the “interaction” module, constrain the rolls, push blocks, and mandrels as rigid bodies, and define the contact relationship between the billet and the rolls and mandrels.
[0034] In step S6, the contact type between the billet and the roll and mandrel is surface-to-surface contact, with friction coefficients of 0.1 and 0.01, respectively. The constraint reference points are the geometric center points of each rigid body. The push block is bound to the geometric center point. The interaction between the billet and the roll is surface-to-surface contact, with the billet as the first contact surface and the roll as the second contact surface. The interaction between the billet and the mandrel is surface-to-surface contact, with the billet as the first contact surface and the mandrel as the second contact surface.
[0035] Step S7: Develop a motion trajectory parameter App based on Matlab to calculate the axial, radial, and rotary rolling motion trajectories of the roll and the motion trajectory of the pusher block.
[0036] In step S7, the total length of the rolling surface of the current rolling slide is measured to be 229 mm. Since the actual movement of the roll is achieved by the contact between the rolling surface of the slide and the roll shoulder, thereby driving the roll to roll purely, the actual distance the rolling roller moves on the billet can be calculated to be 347.3 mm, as shown in the following formula: ; in, This represents the actual distance the roll travels on the billet. This is the total length of the rolling surface of the rolling slide. This refers to the working diameter at the contact point between the roll and the billet. This refers to the diameter of the roll shoulder at the point where the roll contacts the slideway.
[0037] According to the slide track diagram measured by the three-dimensional profile measuring instrument, the length of the finishing section of the slide rolling surface is 36mm, the feeding section, the diameter reduction section and the pressing section are a total of 193mm, and the total length is 229mm.
[0038] This is converted into the distance the rolls travel along the billet using a formula, i.e., the length of the finishing section. L jingzhezong =55mm.
[0039] The feeding section, the reducing section, and the pressing section together constitute a total of L yaxiazong=292.3mm; Meanwhile, according to the trajectory diagram, the trajectories of the feeding section, reducing section, and pressing section are close to a straight line. To simplify the calculation process and save simulation time, referring to the currently commonly used method, the three sections are combined into one inclined straight line, which greatly increases the calculation efficiency while ensuring accuracy. Since the actual production uses a slide rail, when rolling tubes of different sizes, the feeding section and reducing section have a large amount of idle travel of the rolls, without actually contacting the tube blank. Therefore, to further shorten the simulation time, this invention uses a method of backward deduction from the actual position of the roll to the tube blank to define the roll's motion path. This method does not affect the final result and significantly saves the simulation time. The following calculation calculates the remaining downward pressure of the roll when the billet just contacts the roll: The relative position of the billet and the rolling mill is depicted using Solidworks software, and the final calculation target is the remaining downward pressure Δh of the roll when the roll just contacts the billet.
[0040] First, calculate the result from the roll gap. The gap angle A is introduced by 0.35mm, and the opening angle B of the finished pipe is obtained based on A. Based on the supplementary angle C of angle B, angle E is obtained by using the law of sine. At the same time, the law of sine is used again to finally obtain Δh, as shown in the following formula: ; in, Let A be the gap between the rolls, B be the opening angle of the finished tube, C be the supplementary angle of B, and E be the angle for auxiliary calculation (the geometric angle when the tube blank contacts the roll).
[0041] To ensure that the rolls do not contact the billet in the initial position, the remaining reduction ΔH in the initial position of the rolls is calculated using the gap angle A, the opening angle B of the finished tube, the supplementary angle C, and the auxiliary angle E, with an additional 0.05mm allowance added, to finally obtain the remaining reduction ΔH in the initial position of the rolls.
[0042] Remaining reduction amount at the initial position of the roll The actual downward pressure length used in the simulation can be calculated by comparing it with the actual downward pressure h of the slide. The formula is as follows: ; in, This is the actual downward pressure length. h represents the remaining reduction amount, and h represents the actual reduction amount of the slide rail. This is the total downward compression length; Because pipe rolling exhibits extremely high periodicity and consistency in simulation, 50mm billets were used for rolling throughout the project. The actual 54mm finishing section length was too long for the billet used in the simulation; therefore, the finishing section was shortened, and its maximum length was ultimately set to [length to be specified in the original text]. L jingzheng =30mm.
[0043] The single-pass rolling time for the pipeline is t y The modified actual rolling time can be obtained by comparing the optimized rolling path length with the original length. t s The pressing and finishing times are respectively t yaxia and t jingzheng According to the motion law of the cold rolling mill: the rolls move relative to each other on the slide with a specific rolling trajectory to roll the tube. The tube is fed a certain distance and rotated a certain angle within a complete cycle by the feeding chuck and the rotation device, which then drives the rolls to their initial position, with the remaining reduction amount ΔH and reduction time... t yaxia Refinement time t jingzheng Send in time t songjing The feed rate and the single-pass rotation angle of the billet are used to obtain the relative motion relationship between the rolls and the billet, namely, the axial motion trajectory of the rolls, the radial motion trajectory of the rolls, the rotational rolling motion trajectory of the rolls, and the motion trajectory of the pusher block, as shown in the following formulas: ; Furthermore, the written Matlab program will be integrated into an APP for easier operation.
[0044] Step S8: Apply boundary conditions in the "load" module based on the trajectory parameters generated by Matlab.
[0045] In step S8, the rolls apply radial, axial, and circumferential displacements, the pusher applies displacement along the billet feeding direction, and the mandrel remains stationary.
[0046] Step S9: Create a double-precision job in the "job" module and solve it.
[0047] In step S9, the job uses double-precision calculation, and the output precision of the node variables is set to full.
[0048] Step S10: Post-process and analyze the simulation results to verify accuracy.
[0049] In step S10, the residual stress and plastic deformation cloud map are viewed through ABAQUS post-processing, the rolling force data of the geometric center point of the roll is extracted, and the data is compared and verified with the experimental data.
[0050] Therefore, this invention adopts the above-mentioned numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes. Through precise component modeling, material property matching, mesh generation, constraint and contact settings, and post-processing analysis, it achieves accurate prediction of the macroscopic deformation, triaxial stress, residual stress, and rolling force of the tube blank during the rolling process, reducing trial and error costs, shortening the R&D cycle, and improving the dimensional accuracy and internal quality of the finished tube.
[0051] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes, characterized in that, Includes the following steps: Step S1: Based on the structural dimensions of the roll, billet, pusher block and mandrel to be simulated, use the ABAQUS modeling function to establish the corresponding three-dimensional structural parts. The roll size is consistent with the roll used in the rolling test, and the mandrel diameter is equal to the inner diameter of the billet. Step S2: Assign material properties to each component in the ABAQUS property module. For the tube blank, GH3625 high-temperature alloy is selected. The engineering stress-strain curve is obtained through metal tensile test, converted into real stress and real plastic strain, and then input. Step S3: Position each component in the ABAQUS assembly module to form a complete rolling system assembly with three rolls symmetrically distributed at 120 degrees. Step S4: Perform mesh generation and define the minimum mesh unit size and unit type for each component; Step S5: Create a display kinetic analysis step, and set the analysis time, mass scaling, and output parameters; Step S6: Create interactions, constrain the rolls, push blocks, and mandrels as rigid bodies, and define the contact relationship between the billet and the rolls and mandrels; Step S7: Develop a motion trajectory parameter App based on Matlab to calculate the axial, radial, and rotary rolling motion trajectories of the roll and the motion trajectory of the pusher block; Step S8: Apply boundary conditions based on the trajectory parameters generated by Matlab; Step S9: Create a double-precision job and solve it; Step S10: Post-process and analyze the simulation results to verify accuracy.
2. The numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S2, the tensile test of the metal is performed according to GB / T228.1-2021 standard, using three GH3625 specimens from the same batch. The conversion formula between true stress and true plastic strain is shown below: ； in, For actual stress, For engineering stress, For engineering contingency, This represents true plastic strain.
3. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S4, the minimum grid unit size of the tube blank is 0.05 mm, and the unit type is C3D8R; the minimum grid unit size of the roll is 0.05 mm, the mandrel is 0.04 mm, and the pusher is 0.02 mm, and the unit type of all three is R3D4.
4. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S5, the field output interval is 64, outputting variables such as stress, strain, and displacement; the history output interval is 200, outputting energy variables.
5. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S6, the contact type between the billet and the roll and mandrel is surface-to-surface contact, with friction coefficients of 0.1 and 0.01, respectively, and the constraint reference points are the geometric center points of each rigid body.
6. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S7, the actual distance the rolling mill travels on the billet is shown in the following formula: ； in, This represents the actual distance the roll travels on the billet. This is the total length of the rolling surface of the rolling slide. This refers to the working diameter at the contact point between the roll and the billet. This refers to the diameter of the roll shoulder at the point where the roll contacts the slideway.
7. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S7, the remaining reduction amount ΔH at the initial position of the roll is calculated using the gap angle A, the opening angle B of the finished tube, the supplementary angle C, and the auxiliary angle E, and an additional allowance of 0.05 mm is added.
8. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S8, the rolls are subjected to radial, axial, and circumferential displacements, the pusher is subjected to displacement along the billet feeding direction, and the mandrel remains stationary.
9. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S9, the job uses double-precision calculation, and the output precision of the node variables is set to full.
10. A numerical simulation method for three-roll rolling of small-diameter high-temperature alloy tubes according to claim 1, characterized in that, In step S10, the residual stress and plastic deformation cloud map are viewed through ABAQUS post-processing, the rolling force data of the geometric center point of the roll is extracted, and the data is compared and verified with the experimental data.