Continuous forming method of large disc shaft forge piece
By combining free forging and axial closed rolling forming methods, using equal volume cutting and overall heating technology, the problems of uneven metal and poor tissue during the forming process of large disc shaft forgings are solved, and efficient and uniform forming effect is achieved.
Patent Information
- Application Number
- CN202311839705.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2025-07-01
AI Technical Summary
The prior art is difficult to effectively prevent large disc shaft forgings from uneven metal forming, metal flow disorder and metallographic structure during the forming process, and at the same time, the load is high.
The combination of free forging and axial closed rolling forming methods is adopted, and the radial deformation degree of the blank and the deformation degree of the disk end height direction are controlled through equal volume cutting and overall heating. Two different feed amounts are used to ensure the uniformity of the forming.
It effectively avoids the problems of uneven metal forming, disordered metal flow lines and poor metallographic structure, and improves the forming efficiency and performance of large disc shaft forgings.
Smart Images
Figure HDA0004638494310000011
Abstract
Description
Technical Field
[0001] The present invention relates to a forming method for large-sized disk-shaft forgings, and particularly to a continuous forming method for large-sized disk-shaft forgings. Background Art
[0002] With the continuous increase of industrial demands, more and more key parts adopt integral structure designs. Disk-shaft forgings are mostly formed in multiple steps. For the forming techniques of the disk-shaped end, there are mainly open-die forging, die forging on a hydraulic press, die forging on a hammer, and die forging on a screw press, etc. The shaft end is generally formed by open-die forging or extrusion process. For smaller disk-shaft forgings, extrusion is generally used for forming. The above forming means have low efficiency, low precision, and extremely complex production, and especially cannot meet the production requirements of large-sized disk-shaft forgings. Moreover, the materials used also develop towards difficult-to-deform high-strength, high-toughness, and high specific-strength materials, and the improvement of processing technology and equipment is an inevitable trend. In the field of local continuous loading and labor-saving forming, mainly in the forming process of axial closed-die rolling, for the forming process of small-sized disk-shaft forgings during axial closed-die rolling, direct rolling and one-time forming can be carried out. However, when forming large-sized disk-shaft forgings by rolling, incomplete metal filling of large-sized disks or certain defects will occur during metal filling. During the axial closed-die rolling process, generally, the whole process adopts a linear feeding method. However, for large-sized disks, such a feeding method causes a sudden drop in temperature, resulting in uneven metal forming, disordered metal flow lines, and extremely poor metallographic structure. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a continuous forming method for large-sized disk-shaft forgings that can effectively prevent uneven metal forming, disordered metal flow lines, and poor metallographic structure, and has a low load.
[0004] To solve the above technical problem, the continuous forming method for large-sized disk-shaft forgings of the present invention includes the following steps in its technical solution:
[0005] First step, fabricate a corresponding disk-end mold according to the disk end of the disk-shaft forging.
[0006] Second step, cut the blank according to the equal volume principle, and after heating the whole blank to the forging temperature, perform open-die forging on the blank on an open-die forging equipment until the radial deformation degree reaches 40-60%.
[0007] Third step, after locally heating the disk end of the blank, place the blank in the disk-end mold on an axial closed-die rolling forming equipment for rolling forming until the overall deformation degree in the height direction of the disk end reaches 40-60%. When the deformation degree reaches 50%, reduce the feeding amount of the equipment until the forming in the height direction of the disk end is completed.
[0008] Fourth step, perform trimming, heat treatment, and machining on the formed blank to obtain the final large-sized disk-shaft forging.
[0009] Preferably, in the first step, a finite element software is used to perform a finite element numerical analysis on the forming process of the disk end of the disk shaft forging, determine the height-diameter ratio and shape of the disk end corresponding to the disk shaft forging, and machine the cavity of the disk end die according to the obtained data.
[0010] Preferably, in the third step, atomized water-based graphite is sprayed on the cavity of the preheated disk end die.
[0011] Preferably, after the forming in the height direction of the disk end of the disk shaft forging in the third step, the upper die of the disk end die stops feeding, and the angular velocity of the lower die of the disk end die is increased to level the upper surface of the ring part.
[0012] Preferably, in the third step, during the forming process of the disk end of the disk shaft forging, the angular velocity of the lower die of the disk end die is 0.5 - 2 rad / s, and after the forming in the height direction of the preform, the angular velocity is increased to 2 - 3 rad / s.
[0013] Preferably, in the third step, the axial closed-die rolling forming equipment loads the preform with a feed rate of 2 - 4 mm / rad of the equipment output. After the deformation degree reaches 45%, the axial closed-die rolling forming equipment loads the preform with a feed rate of 0.25 - 2 mm / rad of the equipment output until the forming in the height direction is completed.
[0014] Preferably, in the third step, the preheating temperature of the disk end die is 350 degrees.
[0015] Preferably, in the third step, before the start of the disk end forming, the lower die of the disk end die first rotates in advance at an angular velocity of 0.5 rad / s, and then the disk shaft forging is placed into the rotating lower die of the disk end die to form the disk end of the disk shaft forging.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0017] In the continuous forming method of the large-sized disk shaft forging of the present invention, the free forging and axial closed-die rolling forming methods are adopted during the forming process of the disk end of the disk shaft forging to improve the production efficiency. In the axial closed-die rolling forming method, two different feed rates are adopted to ensure that during the disk end forming process, the phenomena of uneven metal forming, disordered metal flow lines, and poor metal structure are avoided, and the performance of the workpiece can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be further described in detail below with reference to the drawings and specific embodiments.
[0019] Figure 1 It is a schematic structural diagram of the disk shaft forging. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] The implementation of the super-large ring segment forging and flash welding composite forming method described in the present invention requires the provision of a forging heating furnace, a press, a manipulator and other equipment.
[0021] The specific implementation is as follows:
[0022] Step 1: According to Figure 1 The upper and lower molds of the disk end mold are designed according to the shape of the disk shaft forging shown. 1 / 2 of the upper surface of the disk end is selected as the contour, and the plumb line 6° is used as the rotation axis to design the upper mold. The parting surface is selected on the upper surface of the disk, and the mold material is 5CrNiMo. The position of the ejector hole is at the center of the lower end of the lower mold, and the size is φ400mm. The draft angle of the lower mold of the disk end mold is selected to be 0.5°. The gap between the upper and lower molds after the mold is closed is 0.3mm. The shaft end of the disk shaft forging is used as a positioning table. The finite element software is used to perform numerical simulation analysis on the axial closed rolling process, and the size of the disk shaft forging blank is determined to be φ150×2000mm. The disk end mold cavity is processed according to the obtained data.
[0023] The second step: shape and design the bars of specific materials according to the specifications and volume of the forgings, and cut them into bars according to the principle of equal volume. The size of the bars is φ300×540mm, and then heat the bars to a certain temperature of 1170℃, heat them with the furnace, and keep them warm for 110 minutes after reaching the temperature. The heated bars are placed on the free forging equipment, and the radial deformation degree is controlled to 50%, so that the bars are stretched to 150×2000mm through free forging.
[0024] Step 3: Place the blank in a furnace heated to 1150 °C and hold for 60 min. Continuously heat the die for the disk end until it reaches 350 °C. Spray the cavity of the disk part die with atomized graphite. Spray slightly less on the upper cavity of the die for the disk end to ensure sufficient friction. The upper surface of the disk end of the disk shaft forging drives the upper die of the die for the disk end to rotate around its center. Start the motor to make the lower die of the die for the disk end have a certain angular velocity of self-rotation. Within 5 s, stabilize the angular velocity of the lower die of the disk shaft forging at 0.5 rad / s. Take out the blank and place it in the lower die of the die for the disk end during rotation. In the initial stage, increase the axial linear velocity of the upper die of the die for the disk end to 1 mm / s until the upper die of the die for the disk end contacts the upper surface of the disk end of the disk shaft forging. Subsequently, load the blank with a feed rate of 2 mm / rad output by the equipment, causing the blank of the disk shaft forging to deform rapidly at the beginning stage. The overall deformation degree during the disk end forming process is 50% in the height direction of the blank. When the deformation degree reaches 45%, load the blank with a feed rate of 1 mm / rad output by the equipment until the forming in the height direction is completed. After the upper die of the die for the disk end reaches the bottom dead center, stop the feed. Increase the angular velocity of the lower die of the die for the disk end by 2 rad / s to level the upper surface of the disk end of the disk shaft forging, enabling the metal in the circumferential and radial directions to flow uniformly and rapidly. Keep rotating for 2 - 3 s, then stop the rotation and take out the blank of the disk shaft forging to complete the forming process.
[0025] Step 4: Trim the formed blank and select tempering treatment for heat treatment to obtain the final disk shaft forging, as Figure 1 shown.
Claims
1. A continuous forming method for a large-scale disk shaft forging, characterized in that, It includes the following steps: In the first step, according to the disk end of the disk shaft forging, the corresponding disk end die is manufactured. In the second step, blanking is carried out according to the principle of equal volume. After the blank is heated as a whole to the forging temperature, the blank is subjected to open-die forging on an open-die forging equipment until the radial deformation degree reaches 40-60%. In the third step, after the disk end of the blank is locally heated, the blank is placed in the disk end die of the axial closed-die rolling forming equipment for rolling forming until the overall deformation degree in the height direction of the disk end reaches 40-60%. When the deformation degree reaches 50%, the feed rate of the equipment is reduced until the forming in the height direction of the disk end is completed. In the fourth step, the formed blank is trimmed, heat-treated, and machined to obtain the final large-scale disk shaft forging.
2. The continuous forming method of the large-scale disk shaft forging according to claim 1, wherein In the first step, finite element software is used to conduct finite element numerical analysis on the forming process of the disk end of the disk shaft forging to determine the height-diameter ratio and shape corresponding to the disk end of the disk shaft forging. The disk end die cavity is machined according to the obtained data.
3. The continuous forming method of the large disk shaft forging according to claim 1, characterized in that, In the third step, atomized water-based graphite is sprayed on the die cavity of the preheated disk end die.
4. The continuous forming method of the large disk shaft forging according to claim 1, characterized in that, In the third step, after the forming in the height direction of the disk end of the disk shaft forging is completed, the upper die of the disk end die stops feeding, and the angular velocity of the lower die of the disk end die is increased to trim the upper surface of the ring part.
5. The continuous forming method of the large disk shaft forging according to claim 1, characterized in that, In the third step, during the forming process of the disk end of the disk shaft forging, the angular velocity of the lower die of the disk end die is 0.5-2 rad / s, and the angular velocity increases to 2-3 rad / s after the forming in the height direction of the preform.
6. The continuous forming method of the large-scale disk shaft forging according to claim 1, characterized in that In the third step, the axial closed-die rolling forming equipment loads the preform with a feed rate of 2-4 mm / rad until the deformation degree reaches 45%, and then the axial closed-die rolling forming equipment loads the preform with a feed rate of 0.25-2 mm / rad until the forming in the height direction is completed.
7. The continuous forming method of the large disk shaft forging according to claim 1, characterized in that In the third step, the preheating temperature of the disk end die is 350 degrees.
8. The continuous forming method of the large-scale disk shaft forging according to claim 1, characterized in that, In the third step, before the start of the disk end forming, the lower die of the disk end die rotates in advance at an angular velocity of 0.5 rad / s, and then the disk shaft forging is placed in the rotating lower die of the disk end die to form the disk end of the disk shaft forging.