Forging method for increasing deformation of small deformation area of symmetrical die forging at low cost
By setting grooves on the bottom surface of the forming cavity of the forging part and performing multiple forging and flipping operations, the problem of poor material properties in the small deformation zone of symmetrical forging parts is solved, achieving low-cost deformation increase and performance improvement.
Patent Information
- Application Number
- CN202511409861.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2025-11-11
Smart Images
Figure CN120920645A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of forging technology, specifically a low-cost forging method for increasing the deformation of the small deformation zone of symmetrical die forgings. Background Technology
[0002] Forgings are forgings formed using a die. Symmetrical forgings refer to forgings that are symmetrical both vertically and horizontally. For symmetrical forgings, the upper and lower dies are typically designed with the symmetrical planes at both ends as the parting planes. For symmetrical forgings where the upper and lower end surfaces are flat or predominantly flat, to facilitate billet preparation, a billet with both upper and lower flat surfaces is currently used for die forging. This method, especially when the forging pressing distance is short, can result in larger deformation in the middle and smaller deformation at the top and bottom, thus creating small deformation zones in the flat areas at both ends of the forging. The material properties are poor in these small deformation zones.
[0003] To achieve more uniform deformation across different parts of the forging and improve its performance, the common approach is to increase pre-forging and adjust the structure to enhance the deformation amount. This not only increases the number of forging passes but also requires an additional set of dies, thus increasing the manufacturing cost of the forging. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a low-cost forging method for increasing the deformation of the small deformation zone of symmetrical die forgings with both upper and lower end surfaces being planar or predominantly planar. This method increases the deformation of the small deformation zone at both the upper and lower end surfaces and reduces the manufacturing cost of the die forgings.
[0005] The technical solution adopted by this invention to solve its technical problem is: a low-cost forging method for increasing the deformation of the small deformation zone of symmetrical forgings, comprising the following steps:
[0006] Using the symmetrical planes at the upper and lower ends of the forging as the parting planes, the upper forming cavity of the upper die and the lower forming cavity of the lower die are designed accordingly. The bottom surface of the upper forming cavity or the lower forming cavity is provided with a groove in the area corresponding to the small deformation zone of the forging.
[0007] The lower end of a blank with both flat surfaces is placed in the lower forming cavity. The upper die is used to forge the upper end of the blank towards the lower die, so that the material of the blank fills the groove, resulting in an intermediate blank with a boss on one end surface. When the intermediate blank is obtained, the upper die and the lower die are in a state of under-compression.
[0008] One end of the intermediate blank with a boss is placed in the lower forming cavity, and the other end of the intermediate blank is forged by the upper die towards the lower die, so that the upper die and the lower die are closed, and the intermediate blank material fills the upper forming cavity, the lower forming cavity and the groove to obtain the final forging.
[0009] The excess material on the surface of the final forging is removed to obtain the die forging.
[0010] Preferably, both the upper and lower surfaces of the forging are planar.
[0011] Preferably, the groove is disposed in the area of the bottom surface of the lower forming cavity corresponding to the small deformation zone of the forging.
[0012] Preferably, the groove is located at the middle position of the area on the bottom surface of the lower forming cavity corresponding to the small deformation zone of the forging.
[0013] Preferably, the width of the groove is b = (0.1~0.4)B, and the depth is h = (0.05~0.2)H, where B is the width of the forging and H is the height of the forging.
[0014] The beneficial effects of the present invention are: the method of the present invention only requires one set of molds to complete the forming of the forging, which increases the deformation of the small deformation zone at the upper and lower ends of the forging, and does not require increasing the number of pre-forging times of the billet or changing its structure. The forming of the forging is more convenient and the forming cost of the forging is also reduced. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of a symmetrical die forging where both the upper and lower surfaces are planar.
[0016] Figure 2 yes Figure 1 Equivalent strain distribution diagram of die forgings;
[0017] Figure 3 This is a schematic diagram of the forging process of the present invention;
[0018] Figure 4 This is an equivalent strain distribution diagram of the forging part of Example 1 after being forged using the method of the present invention;
[0019] Figure 5 This is an equivalent strain distribution diagram of the die-forged part of Example 1 after being die-forged using conventional methods;
[0020] Figure 6 This is an equivalent strain distribution diagram of the forging part of Example 2 after being forged using the method of the present invention;
[0021] Figure 7 This is an equivalent strain distribution diagram of the die-forged part of Example 2 after being die-forged using conventional methods;
[0022] Figure 8 This is an equivalent strain distribution diagram of the forging part of Example 3 after being forged using the method of the present invention;
[0023] Figure 9 This is an equivalent strain distribution diagram of the die-forged part of Example 3 after being die-forged using conventional methods;
[0024] The figure shows: forging 1, billet 3, intermediate billet 4, final forging 5, symmetry plane 12, upper die 21, lower die 22, groove 23, boss 41, upper forming cavity 211, and lower forming cavity 221. Detailed Implementation
[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0026] For symmetrical forgings with planar or predominantly planar surfaces at both ends, conventional forging methods create small deformation zones at both ends. These small deformation zones exhibit poor material properties, affecting the mechanical properties of the forging. For example... Figure 1 As shown, taking a forging 1 that is symmetrical from top to bottom and has flat surfaces at both ends as an example, this forging 1 is V-shaped. The forging 1 was simulated using conventional forging methods with simulation software. The equivalent strain distribution diagram after forming is shown below. Figure 2 As shown. From Figure 2 It is known that a small deformation zone (with equivalent strain less than 0.1) of a certain thickness exists in the planar regions at the top and bottom ends of a die forging. This affects the mechanical properties of the die forging. The thickness of the small deformation zone is related to the pressing distance of the die forging. The smaller the pressing distance of the die forging, the thicker the small deformation zone.
[0027] To achieve more uniform deformation across different parts of a forging and improve its performance, the common approach is to increase the number of pre-forging passes and adjust the structure of the billet to enhance the deformation. This not only increases the number of forging passes but also requires an additional die, thus increasing manufacturing costs. To both increase the deformation of the small deformation zones at the top and bottom ends and reduce manufacturing costs, this invention provides a low-cost forging method for increasing the deformation of the small deformation zones in symmetrical forgings, comprising the following steps:
[0028] S1. Taking the symmetrical plane 12 at the upper and lower ends of the forging 1 as the parting plane, the upper forming cavity 211 of the upper mold 21 and the lower forming cavity 221 of the lower mold 22 are designed accordingly. The upper forming cavity 211 and the lower forming cavity 221 are designed according to the structure and size of the upper and lower ends of the forging. The bottom surface of the upper forming cavity 211 or the lower forming cavity 221 is provided with a groove 23 in the area corresponding to the small deformation area of the forging.
[0029] S2. Place the lower end of the blank 3, whose upper and lower surfaces are both flat, into the lower forming cavity 221. Use the upper die 21 to forge the upper end of the blank 3 towards the lower die 22, so that the material of the blank 3 fills the groove 23, and obtain an intermediate blank 4 with a boss 41 on one end surface. When the intermediate blank 4 is obtained, the upper die 21 and the lower die 22 are in a state of under-pressurization.
[0030] S3. Place one end of the intermediate blank 4 with the boss 41 into the lower forming cavity 221, and use the upper die 21 to forge the other end of the intermediate blank 4 towards the lower die 22, so that the upper die 21 and the lower die 22 are closed, and the material of the intermediate blank 4 fills the upper forming cavity 211, the lower forming cavity 221 and the groove 23 to obtain the final forging 5.
[0031] S4. Remove excess material from the surface of the final forging 5, such as flash, bosses on the end face of the final forging 5, to obtain the die forging 1.
[0032] Specifically, milling machines, grinding machines, and other equipment can be used to remove excess material from the surface of the final forging 5.
[0033] In step S2, the specific under-pressure distance range between the upper mold 21 and the lower mold 22 during the intermediate blank 4 can be obtained experimentally.
[0034] Understandably, in order to facilitate the entry of material into the groove, the sidewall of the groove should smoothly transition to the bottom surface of the corresponding molding cavity.
[0035] The following explanation uses a forging 1 as an example, where both the upper and lower surfaces are flat. Figure 2 As shown, there are small deformation areas in both the upper and lower surface areas of the forging part 1. Therefore, the entire bottom surface area of the upper forming cavity 211 and the lower forming cavity 221 corresponds to the small deformation area. The groove can be set at any position on the bottom surface of the upper forming cavity 211 or the lower forming cavity 221.
[0036] The method of the present invention involves setting a groove 23 on the bottom surface of the upper forming cavity 211 or the lower forming cavity 221 in the area corresponding to the small deformation zone of the forging part. During forming, one end of the blank is first inserted into the groove 23 to obtain an intermediate blank 4 with a boss at one end. Then, the end of the intermediate blank 4 with the boss 41 is placed in the lower forming cavity 221, and the other end of the intermediate blank 4 is forged towards the lower die 22 using the upper die 21. That is, the intermediate blank 4 is flipped 180° to reverse the positions of the upper and lower ends before continuing to forge. The forging process uses upper and lower forging dies. The die without the groove 23 is used to forge one end of the intermediate billet 4 with the boss 41, while the die with the groove 23 is used to forge the other end of the intermediate billet 4 without the boss 41. This flattens the boss 41 at the end of the intermediate billet 4, and a boss is formed at the other end of the intermediate billet 4 (the end without the boss 41), resulting in the final forging 5. This allows for the compression of material in the small deformation zone during the forging process, thereby increasing the material deformation in that zone. Because the forging is symmetrical both vertically and horizontally, rotating the intermediate billet 4 180° during forging does not affect the subsequent forming of the forging. The method of this invention requires only one set of dies to complete the forming of the forging, without increasing the number of pre-forging cycles of the billet 3 or changing its structure (the billet remains a structure with both upper and lower flat surfaces). The forming of the forging is more convenient and the forming cost is lower.
[0037] In embodiments of the present invention, such as Figure 3 As shown, the groove 23 is disposed in the area corresponding to the small deformation zone of the forging on the bottom surface of the lower forming cavity 221. The groove 23, disposed in the area corresponding to the small deformation zone of the forging on the bottom surface of the lower forming cavity 221, facilitates the forming of the forging.
[0038] In this invention, preferably, the groove 23 is positioned at the center of the area corresponding to the small deformation zone of the forging on the bottom surface of the lower forming cavity 221. The number of grooves 23 can be one or more. Generally, the larger the area of the small deformation zone of the forging, the more grooves are provided, and the better the effect on increasing the deformation of the small deformation zone of the forging.
[0039] The dimensions of the groove affect the deformation of the material in the small deformation zone. A smaller groove width and depth result in a relatively smaller effect on increasing the deformation of the material in the small deformation zone. Conversely, an excessively large groove width leads to excessive material waste and has limited improvement in the deformation of the small deformation zone. An excessively large groove depth results in excessive deformation in the small deformation zone, affecting the performance of the forging surface area. Through experiments, in this invention, preferably, the width b of the groove 23 is (0.1~0.4)B, and the depth h is (0.05~0.2)H, where B is the width of the forging and H is the height of the forging.
[0040] Example 1:
[0041] The forging is made of TC21, with a width of 140mm and a height of 200mm. Both the upper and lower surfaces of the forging are flat.
[0042] The above-mentioned die forging was forged using simulation software according to steps S1 to S4 of the present invention, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 4 As shown, the groove 23 is located in the middle of the bottom surface of the lower forming cavity 221, with a width of 15mm and a depth of 10mm.
[0043] The above-mentioned die forging was forged using simulation software and conventional methods, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 5 As shown.
[0044] Example 2:
[0045] The forging is made of TC21, with a width of 140mm and a height of 140mm. Both the upper and lower surfaces of the forging are flat.
[0046] The above-mentioned die forging was forged using simulation software according to steps S1 to S4 of the present invention, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 6 As shown, the groove 23 is located in the middle of the bottom surface of the lower forming cavity 221, with a width of 35mm and a depth of 15mm.
[0047] The above-mentioned die forging was forged using simulation software and conventional methods, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 7 As shown.
[0048] Example 3:
[0049] The forging is made of TC21, with a width of 140mm and a height of 70mm. Both the upper and lower surfaces of the forging are flat.
[0050] The above-mentioned die forging was forged using simulation software according to steps S1 to S4 of the present invention, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 9 As shown, the groove 23 is located in the middle of the bottom surface of the lower forming cavity 221, with a width of 55mm and a depth of 15mm.
[0051] The above-mentioned die forging was forged using simulation software and conventional methods, and the equivalent strain distribution diagram of the die forging was obtained as follows. Figure 9 As shown.
[0052] from Figures 4 to 9 It can be seen that the method of the present invention significantly increases the deformation of the small deformation zone of the forging, and has a better effect on changing the deformation of the small deformation zone of the forging.
Claims
1. A low-cost forging method for increasing the deformation of the small deformation zone of symmetrical die forgings, characterized in that, Includes the following steps: Using the symmetrical planes at the upper and lower ends of the forging as the parting planes, the upper forming cavity (211) of the upper mold (21) and the lower forming cavity (221) of the lower mold (22) are designed accordingly. The bottom surface of the upper forming cavity (211) or the lower forming cavity (221) is provided with a groove (23) in the area corresponding to the small deformation zone of the forging. The lower end of the blank (3) with both upper and lower surfaces being flat is placed in the lower forming cavity (221). The upper end of the blank (3) is forged by the upper mold (21) towards the lower mold (22) so that the material of the blank (3) fills the groove (23) and an intermediate blank (4) with a boss (41) on one end surface is obtained. When the intermediate blank (4) is obtained, the upper mold (21) and the lower mold (22) are in a state of under-pressurization. One end of the intermediate blank (4) with a boss (41) is placed in the lower forming cavity (221), and the other end of the intermediate blank (4) is forged by the upper die (21) towards the lower die (22), so that the upper die (21) and the lower die (22) are closed, and the material of the intermediate blank (4) fills the upper forming cavity (211), the lower forming cavity (221) and the groove (23) to obtain the final forging (5); Remove excess material from the surface of the final forging (5) to obtain the die forging.
2. The low-cost forging method for increasing the deformation of the small deformation zone of symmetrical forgings as described in claim 1, characterized in that, Both the upper and lower surfaces of the forging are planar.
3. The low-cost forging method for increasing the deformation of the small deformation zone of symmetrical forgings as described in claim 1, characterized in that, The groove (23) is located in the area corresponding to the small deformation zone of the forging on the bottom surface of the lower forming cavity (221).
4. The low-cost forging method for increasing the deformation of the small deformation zone of symmetrical forgings as described in claim 3, characterized in that, The groove (23) is located at the middle position of the area of the bottom surface of the lower forming cavity (221) corresponding to the small deformation zone of the forging.
5. The low-cost forging method for increasing the deformation of the small deformation zone of a symmetrical forging as described in any one of claims 1 to 4, characterized in that, The width of the groove (23) is b = (0.1~0.4)B, and the depth is h = (0.05~0.2)H, where B is the width of the forging and H is the height of the forging.