Rolling method of die forging wing rail
By employing a two-stage heating, two-stage upsetting, and multi-station rolling process for the die-forged wing rail, the problem of low yield of die-forged wing rails was solved, achieving efficient production and stable quality of die-forged wing rails, thus meeting the high requirements of railway turnouts.
Patent Information
- Application Number
- CN202511808632.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-01-23
AI Technical Summary
Due to defects in heating effect, post-forging folding, and manufacturing process, die-forged wing rails could not be formally produced, resulting in a low yield and failing to meet the high requirements of railway turnouts.
The billet is pre-forged using a two-stage heating and two-stage upsetting process. Then, through a multi-station rolling process, including primary forging, intermediate forging, final forging, and edge trimming, the metal flow and forming are controlled, excess metal is removed, and full filling is ensured.
It improved the yield of die-forged airfoil rails, enabled mass production, ensured product precision and quality stability, improved production efficiency and reduced energy consumption, and improved the internal structure and mechanical properties of the metal.
Smart Images
Figure CN121373294A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of railway track manufacturing technology, and in particular relates to a rolling method for die-forged wing rails. Background Technology
[0002] Forged wing rails are mainly used in railway turnout systems. They are key components that ensure the safety of trains passing through turnouts and improve the load-bearing capacity and service life of turnouts. Their use is directly related to the high requirements of railway transportation for turnout performance.
[0003] A turnout is the "throat" of a railway line, responsible for enabling trains to switch from one track to another. During the process of a train passing through a turnout, the contact state between the wheels and the track is complex. As an important component of the turnout, the wing rail must undertake the following core functions: 1) Guide the wheels to pass smoothly through the frog, avoid the wheels impacting the frog center, and reduce the risk of derailment; 2) Bear the vertical pressure and lateral impact force of the train wheelset to ensure the stability of the track structure; 3) Cooperate with the frog, switch rail, and other components to ensure the continuity of the track section and reduce vibration and noise when the train passes through the turnout.
[0004] However, due to issues such as heating effect, post-forging folding, and manufacturing process defects, die-forged airfoil rails have not been put into formal production. Therefore, we propose a rolling method for die-forged airfoil rails to solve the aforementioned problems. Summary of the Invention
[0005] In view of this, in order to solve the problem that forged airfoil rails are unable to enter formal production due to limitations in heating effect, post-forging folding, and manufacturing process defects, the present invention provides a rolling method for forged airfoil rails. By improving the traditional production process, the yield of forged airfoil rails is increased, each cross-section can be fully filled, and batch production capacity can be formed.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a rolling method for forged airfoil rails, comprising the following steps: S1. Billet forging: S11. First, heat the upsetting part of the rail. After heating, place it into a special upsetting mold. Then, apply pressure through hydraulic equipment to redistribute the volume of the steel billet within the mold to obtain the upset die-forged wing rail. S12. After upsetting, remove excess metal from the easily foldable parts of the die-forged airfoil to obtain a spare die-forged airfoil. S2. Die-forged airfoil rolling: S21. The spare die-forged airfoil is heated for the first time. After heating, the initial forging and intermediate forging are completed sequentially through the corresponding special rolling die. S22. After the intermediate forging is completed, the forged airfoil is heated a second time and the final forging is completed through a special rolling die to obtain the final forged airfoil. S23. Finally, the flash metal generated during the final forging process is removed to obtain the finished product.
[0007] Furthermore, the upsetting process in step S11 adopts a manufacturing method of two heating and two upsetting. First, the area close to the base material is upset to achieve local volume change. Then, the rail end area is upset to achieve connection of the entire deformation area.
[0008] Furthermore, the rail billet is heated in a medium-frequency heating furnace, and the forging temperature of the upsetting part of the rail is heated to 1050~1150℃.
[0009] Furthermore, in step S12, the milling length of the long limb is controlled according to the forging area ratio of the long limb to the short limb, so as to meet the filling requirements of the die-forged airfoil.
[0010] Furthermore, after upsetting, inclined surfaces need to be milled on both sides of the rail base to control the height of the rail edge to meet the mold requirements.
[0011] Furthermore, the slope of the rail bottom is matched with the draft angle of the mold.
[0012] Furthermore, in step S2, the heating temperature of the forged airfoil is controlled at 1050~1150℃ in both heating processes.
[0013] Furthermore, in step S21, the initial forging can increase the height of the rail and reduce the thickness of the rail web, thereby improving the asymmetry of the rail base.
[0014] Furthermore, in step S21, the thickness of the rail web can be further reduced by intermediate forging, and the rail head can be shaped to its approximate profile.
[0015] Furthermore, in step S22, the final forging process can fully form the rail head, rail web, and rail base, and remove excess metal from the flash grooves on both sides of the rail head and rail base.
[0016] The embodiments of the present invention have the following beneficial effects: This invention pre-forges the billet before rolling, employing a two-stage heating and two-stage upsetting process. Excess metal is removed after upsetting to meet the requirements of filling and die insertion. Then, the forged airfoil is rolled using a two-stage heating multi-station rolling process. By improving the traditional production process, the yield of forged airfoil rolling can be increased, ensuring full filling of each cross-section and enabling mass production.
[0017] This invention utilizes a multi-station rolling process to precisely control the size and shape of the airfoil rail, ensuring product accuracy and quality stability. Simultaneously, multiple forging steps can be completed in a single heating cycle, improving production efficiency and reducing energy consumption. Furthermore, this process can improve the internal structure of the metal, enhancing the mechanical properties of the airfoil rail.
[0018] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description
[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a process flow diagram of a rolling method for a die-forged airfoil according to the present invention; Figure 2 A schematic diagram of the cross-sectional structure of existing raw material 60AT1; Figure 3 This is a schematic diagram of the cross-sectional structure of a forged airfoil. Figure 4 A schematic diagram of the upsetting structure of the 60AT1; Figure 5 This is a schematic diagram of the finished dimensions and structure of a die-forged airfoil rail; Figure 6 This is a schematic diagram of the rail component structure after the first upsetting. Figure 7 This is a schematic diagram showing the length of the upsetting region; Figure 8 This is a schematic diagram of the machining removal process after upsetting; Figure 9 A schematic diagram showing the comparison between the thickness of the 60AT1 rail after upsetting and the thickness of the basic rail bottom; Figure 10 This is a schematic diagram of the entire forming process of a die-forged airfoil rail. Figure 11 This is a schematic diagram of the initial forging structure of a die-forged airfoil rail. Figure 12 This is a schematic diagram of the forging and pressing structure in a die-forged airfoil rail; Figure 13 This is a schematic diagram of the final forging structure of a die-forged airfoil rail. Figure 14 This is a schematic diagram showing the change in the rolling deformation area after the finished die-forged airfoil rails are connected. Detailed Implementation
[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0021] This embodiment provides a rolling method for forged airfoil rails, such as... Figure 2 The image shows the raw material used for forging airfoil rails, specifically the 60AT1 rail. 60AT1 is an asymmetric cross-section rail. (The image is missing from the original text.) Figure 3 The diagram shown is a schematic of a forged airfoil rail. The cross-sectional areas of the 60AT1 and the forged airfoil rail are compared in Table 1 below: Table 1: Comparison of Cross-sectional Area between 60AT1 and Forged Airfoil Rail (Unit: mm) 2 )
[0022] According to the comparison of the cross-sectional area ratio of the two in Table 1, it can be seen that the area of 60AT1 and the forged airfoil is not much different, with an area ratio of 1.08, which is close to equal area.
[0023] However, the rail head area varies significantly. Without considering factors such as flash, longitudinal flow, and flow capacity, the rail head area ratio is only 0.79. If only the rail web is used for compensation, the ratio of the ideal compensation area to the actual area is:
[0024] Only when 75.7% of the excess metal in the rail web flows to the rail head can the basic filling of the rail head be achieved. Therefore, in order to ensure sufficient metal processing for the rail head, the 60AT1 rail must be upset before rolling the die-forged wing rail.
[0025] Upsetting involves heating the upset portion of the rail to forging temperature using hydraulic and mechanical forging equipment, typically between 1050 and 1150°C. After reaching 1150°C, the rail is placed into a specialized upsetting die cavity. The upper and lower dies are then closed, and axial pressure is applied via hydraulic equipment. This causes the steel billet to undergo volume changes under the constraint of the die, resulting in a redistribution effect. Specifically, the metal in the target upsetting area flows into the empty space within the die cavity, achieving the effect of "volume aggregation + dimensional shaping."
[0026] Table 2: Comparison of cross-sectional areas of 60AT1 upset and forged airfoil rails (unit: mm)2 )
[0027] The cross-sectional area of 60AT1 steel rails increases significantly after upsetting, such as Figure 4 As shown in the figure, it is a schematic diagram of upsetting 60AT1. Assuming that e is 3mm, the cross-sectional area comparison of the two is shown in Table 2 above. After upsetting, the overall area ratio is 1.27, the rail head area ratio is also significantly improved, the excess metal in the rail web is easy to flow, and the entire cross-section of the die-forged airfoil is fully filled.
[0028] Once the amount of metal in the upset AT rail meets the forging requirements of the airfoil rail, the metal flow direction during the forging process is discussed. The comparison of the metal area after upset is shown in Table 2 above. The ratio of the two rail heads is 0.94. Ideally, the area supplemented by the rail web is approximately:
[0029] At this point, the metal of the rail head and rail web meets the forging requirements.
[0030] In this embodiment, as Figure 5 The diagram shows the structural dimensions of the finished forged airfoil rail. The overall length of the forged airfoil rail rolled from 60AT1 is 930mm, so the effective upsetting deformation length of 60AT1 must be ≥930mm. In the actual processing, the effective heating length of the medium-frequency heating furnace is 600mm, so the upsetting process adopts a two-heating, two-upsetting manufacturing process. First, the area close to the base material is upset to achieve a local volume change, and then the rail end area is upset, such as... Figure 6 , Figure 7 As shown, this allows the entire deformation area to be connected, achieving the required upsetting length.
[0031] Folding defects can occur during the forging process. The cause of folding is that after the local upsetting of the rail part is completed, the amount of metal increases and the deformation of the rail in the mold cavity is large. Since the forging mold is a closed mold cavity with upper and lower dies, the mold closing speed is fast and the pressure is high. The excess metal cannot be discharged in time in the form of flash. Therefore, during extrusion molding, the defect of multi-layer folding of metal will occur.
[0032] To address this issue, after upsetting, excess metal is removed from the easily foldable parts of the forged airfoil. A detailed machining diagram is shown below. Figure 8 As shown, folding defects are effectively eliminated while ensuring full forging and molding.
[0033] Furthermore, as shown in Table 2 above, the rail base of the upset 60AT is approximately 48% higher than the actual requirement. The area of the long and short limb sides of the upset 60AT is 1614.5 mm larger than that of the half-wing rail base. 2Examples are shown in Table 3 below: Table 3: Comparison of track base area of 60AT long and short limb sides and 1 / 2 wing rail after upsetting
[0034] As shown in Table 3, the area ratio of the long limb reaches 1.77, which means the excess metal will cause folding, directly affecting the forging quality. Since the two sides of the rail base after forging are symmetrical, it is considered to process the long limb to be approximately the same length as the short limb to ensure consistent deformation after forging. Therefore, approximately 30mm is removed from the long limb, and the area ratio after removal is shown in Table 4 below: Table 4: Area Comparison Table After Measurement Removal
[0035] As shown in Table 4, the ratio of the forging area of the long limb to that of the short limb is about 1.2, which meets the usage requirements.
[0036] After milling, the ratio of the cross-sectional area of the AT rail to the area of the forged airfoil rail is shown in Table 5 below: Table 5: Comparison of cross-sectional area of milled AT rails and forged airfoil rails
[0037] In the actual forging process of die-forged airfoil rails, a relatively thick rail base machining allowance is retained, which may lead to insufficient metal content during the forging process. Therefore, the milling length of the long limb should be appropriately controlled. When the length of the die-forged airfoil rail section is 530mm, and the milling length of the upset AT rail is 380mm, the ratio of their metal content is:
[0038] When the metal ratio is 1.21, the filling requirements of the die-forged airfoil can be met, so the controlled milling length can be 380mm.
[0039] After upsetting, the cross-section within the first 190mm needs to be rolled into a standard 60kg / m rail cross-section. The ratio of this cross-section to the area of the upset AT rail is shown in Table 6 below: Table 6: Area Comparison of Upset AT Rails and 60kg / m Rails
[0040] As shown in Table 6, the area of the upset AT rail is much larger than the forging requirement of a 60kg / m rail. For example... Figure 9As shown, the right image is a cross-sectional view of a 60kg rail, with a rail leg edge height of 12mm. The left image is a cross-sectional view of an upset AT rail, with rail leg edge heights of 24mm and 25mm respectively. This will make it difficult to insert the rail leg into the mold. Therefore, considering the subsequent machining, the rail leg edge height of the upset AT rail must be milled to 14-15mm to meet the mold insertion requirements. The slope of the rail bottom can be directly referenced from the draft angle of the mold.
[0041] After completing the above procedures, the pre-forging preparation work for rail components is completed, that is, the pre-forging of the rail blank is completed, so that the upset rail can enter the subsequent rolling process and the finished product rolling can begin.
[0042] In the rolling process of the present invention, the die-forged airfoil is rolled using a two-stage heating multi-station rolling process. The first heating is used for the rolling of the first and second stations, and the second heating is used for the rolling of the third station. The heating temperature of the die-forged airfoil is controlled within the range of 1050~1150℃, preferably 1150℃.
[0043] like Figure 10 The diagram shows the process of a die-forged airfoil rail undergoing a multi-station rolling process. The entire rolling process mainly consists of four steps: initial forging, intermediate forging, final forging, and final edge trimming.
[0044] The first step is initial forging, such as... Figure 11 The diagram shows a schematic of the initial forging process for a die-forged airfoil rail. Figure (a) shows the open die state. The billet is placed in the special die for initial forging, with the rail base facing right and the rail head facing left, and then the die is closed. During the initial forging process, Figure (b) shows the rail component after the die is closed. At this time, the die is tightly closed, and it can be seen that after pressing, the rail web lengthens towards the rail head and rail base, while the rail base length is shortened. Through the initial forging process, the height of the rail is increased, the thickness of the rail web is reduced, and the asymmetry of the rail base is improved.
[0045] The second process is intermediate forging, such as... Figure 12 The diagram shows a schematic of the forging process in a die-forged airfoil rail. As shown in Figure (a), the die is in the open state. The initially forged billet is then placed into the die, with the rail bottom facing right and the rail head facing left, and then the die is closed. During the intermediate forging process, as shown in Figure (b), the rail component is in the closed state. At this time, the die is tightly closed. The main purpose of the intermediate forging stage is to further reduce the thickness of the rail web and to shape the approximate profile of the rail head.
[0046] The third process is final forging, such as... Figure 13The diagram shows the final forging process of a die-forged airfoil rail. As shown in Figure (a), the mold is in the open state. The forged billet is then placed into the mold, with the rail placement consistent with the initial and intermediate forging processes. The rail base faces right, and the rail head faces left, but the rail web and rail head do not fully contact the mold. The mold is then closed. Figure (b) shows the rail component after the mold is closed. It can be seen that after the mold closes, the billet shape has become a die-forged airfoil rail specimen. The rail head, rail web, and rail base are formed, and excess metal is removed from the flash grooves on both sides of the rail head and rail base. Finally, the 60AT1 rail is formed into a die-forged airfoil rail structure.
[0047] The fourth step is edge trimming, which is also the last step in this rolling process. The flash metal generated during the final forging is removed to obtain the final product.
[0048] like Figure 14 As shown, the upsetting area is rolled in multiple stations and then trimmed to achieve its final shape. The upsetting area is then transformed into a die-forged wing rail section and a 60kg / m section. The 60kg / m rail is then welded to the standard rail on the track.
[0049] Using the rolling method described above, 60AT1 steel rails can be forged into wing rail profiles, with the front section being a 60kg / m steel rail connected to the track. Wing rails produced using this method have a full profile, stable quality, and can be mass-produced.
[0050] Die-forged airfoil rails utilize a multi-station rolling process to precisely control their dimensions and shape, ensuring product accuracy and quality stability. Furthermore, multiple forging steps can be completed in a single heating cycle, improving production efficiency and reducing energy consumption. In addition, this process can improve the internal structure of the metal, enhancing the mechanical properties of the airfoil rail.
[0051] A rolling method for a die-forged airfoil includes the following steps: S1. Billet forging: S11. First, heat the area of the rail billet close to the base material to 1050~1150℃ using a medium-frequency heating furnace. After heating, place it into a special upsetting mold. Then, apply pressure through hydraulic equipment to redistribute the volume of the steel billet within the mold, achieving local volume change and obtaining the forged flange rail after the first upsetting. S12. The rail end area of the rail billet is heated to 1050~1150℃ in a medium frequency heating furnace. After heating, it is placed in a special upsetting mold. Then, pressure is applied by hydraulic equipment to redistribute the volume of the steel billet in the mold and form it, so that the entire deformation area is connected, and the forged wing rail after the second upsetting is obtained. S13. After upsetting, based on the forging area ratio of the long limb to the short limb, remove the excess metal from the easily foldable parts of the die-forged airfoil and control the milling length of the long limb to obtain a spare die-forged airfoil so as to meet the filling requirements of the die-forged airfoil. S14. After upsetting, inclined surfaces need to be milled on both sides of the rail bottom. The slope of the rail bottom should be matched with the draft angle of the mold to control the height of the rail edge to meet the mold entry requirements. S2. Die-forged airfoil rolling: S21. First, heat the spare die-forged wing rail to 1050~1150℃. After heating, complete the initial forging and intermediate forging in sequence through the corresponding special rolling die. The initial forging can increase the height of the rail and reduce the thickness of the rail web to improve the asymmetry of the rail base. The intermediate forging can further reduce the thickness of the rail web and shape the rail head to the approximate profile. S22. After the intermediate forging is completed, the forged wing rail is heated to 1050~1150℃ for the second time, and the final forging is completed through a special rolling die to obtain the final forged wing rail. The final forging can form the rail head, rail web and rail bottom of the rail, and remove excess metal from the flash grooves on both sides of the rail head and rail bottom. S23. Finally, the flash metal generated during the final forging process is removed to obtain the finished product.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A rolling method for die forging a wing rail, characterized by, The method comprises the following steps: S1, blank forging: S11, first heat the rail upsetting part, then put it into a special upsetting die, and then press it through a hydraulic device to make the volume of the billet redistribute in the die to obtain an upsetting die forged wing rail; S12, after the upsetting is completed, remove the excess metal amount of the easy folding part of the die forged wing rail to obtain a standby die forged wing rail; S2, die forging wing rail rolling: S21, first heat the standby die forged wing rail, and then complete the initial forging and intermediate forging through the corresponding special rolling die; S22, after the intermediate forging is completed, heat the forged die forged wing rail for the second time, and complete the final forging through the special rolling die to obtain the finally formed die forged wing rail; S23, finally, the flash metal generated in the final forging process is removed to obtain the finished product.
2. A rolling method for die forging a wing rail as set forth in claim 1, characterized in that, The upsetting process in step S11 adopts a manufacturing method of twice heating and twice upsetting, first upsetting the region near the base material to realize the volume change of the local region, and then upsetting the rail end region to realize the connection of the whole deformation region.
3. A method of rolling a die-forged wing rail as defined in claim 2, characterized in that, The steel rail blank is heated by a medium frequency heating furnace, and the forging temperature of the rail upsetting part is heated to 1050-1150℃.
4. A method of rolling a die-forged wing rail as defined in claim 3, wherein In step S12, according to the forging area ratio of long limb to short limb, the milling length of long limb is controlled to meet the filling requirement of die forged wing rail.
5. A method of rolling a die-forged wing rail as defined in claim 4, wherein After upsetting, inclined surfaces are milled on both sides of the rail bottom to control the height of the rail limb edge to meet the mold entry requirement.
6. A method of rolling a die-forged wing rail as defined in claim 5, wherein The slope of the rail bottom is matched with the draft angle of the die.
7. A method of roll ing a die forged wing rail as claimed in claim 1 or 6, characterized in that, In step S2, the heating temperature of the die forged wing rail is controlled at 1050-1150℃.
8. A method of rolling a die-forged wing rail as defined in claim 7, characterized in that, In step S21, the height of the rail can be increased by initial forging, and the thickness of the rail waist can be reduced to improve the degree of asymmetry of the rail bottom.
9. A method of rolling a die-forged wing rail as defined in claim 8, characterized in that, In step S21, the thickness of the rail waist can be further reduced by intermediate forging, and the rail head is shaped to the approximate profile.
10. A method of rolling a die-forged wing rail as defined in claim 9, wherein, In step S22, the rail head, rail waist and rail bottom are all shaped by final forging, and the excess metal is removed from the flash groove on both sides of the rail head and rail bottom.