A method for determining the position of the taper roller oblique rolling piercing head
By introducing damage factor and finite element simulation, optimizing the craft parameters of oblique rolling perforation, the best position of the top head position is determined, the problem of choosing dependency experience in the top position of the existing technology, and improving the perforation efficiency and equipment performance.
Patent Information
- Application Number
- CN202211084073.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-06
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2042-09-06
AI Technical Summary
During the oblique rolling perforation process, the selection of the head position depends on experience, resulting in uneven perforation resistance, affecting the perforation efficiency and equipment performance, and there is a lack of optimization research based on damage factor analysis.
By introducing damage factors, establishing a damage model and using finite element simulation, the range of process parameters is optimized, orthogonal experiments are conducted to determine the best process parameters, and finally the head is placed in the area with the largest core damage value to determine the position of the head.
The precise determination of the position of the plug is achieved, the resistance of the plug is reduced, the life of the plug is improved, and the performance of the equipment is fully utilized.
Smart Images
Figure CN115401073B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of material processing, and in particular to a method for determining a position of a taper roller oblique rolling piercing head. Background Art
[0002] Oblique rolling piercing is a process of plastic deformation of the rolled piece from solid billet to hollow tube in a spiral motion. After the tube is dragged into the deformation zone, the plastic deformation gradually penetrates from the outer surface to the core, and a two-way tensile stress state is formed in the center along the advancing and widening direction of the tube, which is easy to induce the phenomenon of looseness, crack initiation and gradual evolution into cavities, which is called Mannesmann Effect (ME) and the tube diameter compression rate corresponding to the formation of cavities is called critical diameter reduction rate (ε lj ). Top front compression ratio (ε dq ) must be less than εlj to avoid scrap due to cavities.
[0003] At present, in the actual production process, the position of the plug is generally selected within a certain range based on experience. lj Large enough to not form a cavity. However, although the Mannesmann effect can induce the appearance of cavities, in the process of cavity formation, cracks are formed by embryo formation, incubation, expansion and convergence, and gradually evolve into macro cracking. Therefore, corresponding to the plug position in different optional ranges, the perforation resistance is different, and the perforability is significantly different. Because the Mannesmann effect is closely related to the distribution law of the damage factor, under the premise that no macro crack cavity is formed, the larger the damage factor, the more obvious the plastic deformation, the smaller the resistance of the perforating plug to the perforation process, and the more conducive to the secondary bite of the perforation process. However, there has been no published research results on the optimization of deformation parameters and plug position based on damage factor analysis. Summary of the invention
[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a method for determining the position of the plug during oblique rolling and piercing by a tapered roller. The method introduces a damage factor into the oblique rolling and piercing deformation zone, and uses the damage factor to express the severity of the Mannesmann effect in the core of the billet, thereby determining the plug position, reducing the plug resistance, and increasing the plug life.
[0005] The present invention provides a method for determining the position of a taper roller oblique rolling piercing head, comprising the following steps:
[0006] 1) The damage model was established based on the Oyane criterion, and single-factor simulation experiments were carried out using finite element simulation to analyze the influence of different process parameters on the internal damage factor of the oblique-rolled solid bar. The maximum damage value under different process parameters was linearly fitted, and the critical damage value of the material was taken as the limit to select the process parameter range close to the critical damage value.
[0007] 2) Taking the maximum damage value as the goal, an orthogonal test is performed according to the process parameter range obtained in step 1) to determine the optimal process parameters regarding the damage factor;
[0008] 3) Analyze the damage distribution cloud diagram of the obliquely rolled solid bar under the optimal process parameters in step 2), place the plug in the area with the largest damage value in the center, compare the damage value before the plug, and take the maximum damage value as the goal to determine the plug position.
[0009] Preferably, the process parameters include: feed angle β, rolling angle γ, roll speed n, temperature T and diameter reduction rate ε.
[0010] In the specific operation of the method for determining the position of the tapered roller oblique rolling piercing plug described in the present invention, the severity of the Mannesmann effect in the core of the blank is expressed by a damage factor. In order to obtain a maximum damage value less than the material damage threshold, an orthogonal test is performed on the selected process parameter range to obtain the best process parameter combination. The plug is placed in the area with the largest core damage value, and its front-end damage value is compared to determine the plug position. Compared with the conventional method of determining the plug position through experience, the plug position is more accurate, the plug resistance can be reduced, and the equipment performance is fully utilized. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a diagram of the invention process.
[0012] Figure 2 Schematic diagram of the oblique rolling piercing deformation zone.
[0013] Figure 3 Schematic diagram of the finite element model for cross-rolling of solid bars.
[0014] Figure 4 for Figure 3 AA section view.
[0015] Figure 5 It is the damage factor distribution diagram of deformation zone.
[0016] Figure 6 Fitting curve of maximum damage value changing with feed angle.
[0017] Figure 7 Fitting curve of maximum damage value changing with rolling angle.
[0018] Figure 8 Fitting curve of maximum damage value changing with roller speed.
[0019] Fig. 9 Fitting curve of maximum damage value changing with reduction rate.
[0020] Fig.10 Fitting curve of maximum damage value changing with temperature.
[0021] Fig.11 This is the damage distribution diagram of the orthogonal test.
[0022] Fig.12 This is a diagram showing the change in damage factor at different top front pressure rates. DETAILED DESCRIPTION
[0023] The present invention is further described in detail below in conjunction with the accompanying drawings:
[0024] refer to Figure 2-Figure 4 The present invention provides a method for determining the position of a piercing head of a tapered roller for oblique rolling, comprising the following steps:
[0025] 1) The damage model was established based on the Oyane criterion, and a single-factor simulation experiment was carried out using finite element simulation to analyze the influence of different process parameters on the internal damage factor of tapered roller rolled solid bars. The maximum damage value under different process parameters was linearly fitted, and the critical damage value of the material was taken as the limit to select the process parameter range close to the critical damage value.
[0026] 2) Taking the maximum damage value as the goal, an orthogonal test is performed according to the process parameter range obtained in step 1) to determine the optimal process parameters regarding the damage factor;
[0027] 3) Analyze the damage distribution cloud diagram of the obliquely rolled solid bar under the optimal process parameters in step 2), place the plug in the area with the largest damage value in the center, compare the damage value before the plug, and take the maximum damage value as the goal to determine the plug position.
[0028] Embodiment 1
[0029] The calculation model was established, the blank specification was Φ63mm×180mm, and the single factor simulation experiment was carried out using finite element simulation. Figures 6 to 10 The figure shows the fitting curve of the maximum damage value under different process parameters. According to the change of the core damage value and the critical damage value of the material as the limit, the process parameter range close to the critical damage value is selected: the feed angle β is 10°~14°, the rolling angle γ is 12°~14°, the reduction rate ε is 17%, the roll speed n is 30 rpm~50 rpm, and the rolling temperature T is 1050 ℃~1150 ℃.
[0030] Taking the maximum damage as the target, an orthogonal test was conducted on the selected process parameters. The results are as follows: Fig.11 As shown, the core damage value of experiment 6 is the largest, which is 0.63. The optimal process parameters are determined as feed angle β of 14°, rolling angle γ of 13°, roll speed of 50 rpm, and temperature of 1050 ℃.
[0031] The plug is placed in the area with the largest core damage value under the optimal process parameters, and its front damage value is compared. The results are as follows: Fig.12 As shown in the figure, when the top front pressure reduction rate is 12%, the top front damage value is the largest, so the top head position is when the top front pressure reduction rate is 12%.
Claims
1. A method for determining the position of a taper roller oblique rolling piercing head, characterized in that: The following steps are involved: 1) The damage model was established based on the Oyane criterion, and single-factor simulation experiments were carried out using finite element simulation to analyze the influence of different process parameters on the internal damage factor of the oblique-rolled solid bar. The maximum damage value under different process parameters was linearly fitted, and the critical damage value of the material was taken as the limit to select the process parameter range close to the critical damage value. 2) Taking the maximum damage value as the goal, an orthogonal test is performed according to the process parameter range obtained in step 1) to determine the optimal process parameters regarding the damage factor; 3) Analyze the damage distribution cloud diagram of the obliquely rolled solid bar under the optimal process parameters in step 2), place the plug in the area with the largest damage value in the center, compare the damage value before the plug, and take the maximum damage value as the goal to determine the plug position.
2. A method for determining the position of a taper roller oblique rolling piercing head as claimed in claim 1, characterized in that: The process parameters include: feed angle β, rolling angle γ, roll speed n, temperature T and diameter reduction rate ε.