Forging die and forging method for metal disc parts

Abstract

According to the forging method, the height-diameter ratio of a cylindrical blank is determined on the basis of the size of the metal disc part needing to be formed, then the cylindrical blank is placed in a cavity of the die, a step-by-step forging method is adopted, the center portion of the metal disc part is formed firstly, and then the center portion of the metal disc part is formed. And forming the edge part, belonging to the disc type forge piece, of the gold structure to obtain the metal disc type piece. The method has the beneficial effects that the maximum load required by forging forming can be reduced, a pre-forging step or a complex initial machining step is cancelled, demolding is facilitated, the deformation of the forge piece is increased, and the strength and plasticity of the forge piece product and the performance consistency of the product are improved. And the average dependent variable of the forge piece is 6-10 times that of a conventional method. According to the method, the blank is subjected to constraint centering, so that the position deviation of the blank in the forging process is effectively avoided.

Description

Technical Field

[0001] This invention belongs to the field of plastic forming of metal materials, and in particular relates to a forging die and forging method for metal disc-shaped parts. Background Technology

[0002] Forging is a key process in the manufacture of metal parts, and its products are widely used in many fields such as transportation, aerospace, military, and energy. The level of high-end metal parts forging technology is considered one of the main indicators of a country's advanced manufacturing level and capabilities. High efficiency, high precision, low energy consumption, and intelligentization are important development directions for forging technology.

[0003] Forging materials include aluminum alloys, copper alloys, titanium alloys, high-temperature alloys, composite materials, high-strength steel, and intermetallic compounds. Among them, titanium alloys, high-temperature alloys, high-strength steel, and intermetallic compounds have high deformation resistance and are limited by forging temperature (for example, if the forging temperature of titanium alloy exceeds the β phase transformation temperature, it will lead to coarse microstructure and decreased forging performance). The maximum forming load of forgings is large, requiring forging equipment with larger tonnage. Especially for disc-shaped parts with small height-to-diameter ratio, due to the constraint of friction on the surfaces of the upper and lower dies, the radial flow of metal is difficult, and the forging force rises sharply in the later stage of filling, which can easily cause die failure, uneven deformation of forgings, and severe stress concentration (Yu Haofei, Li Yugui, Zhao Guanghui, et al. Hot deformation damage behavior and upsetting crack prediction of 50Cr5NiMoV alloy steel [J]. Forging Technology, 2025, 50(06): 1-7.).

[0004] On the other hand, in order to ensure sufficient plastic deformation of the forgings, forging billets with a large aspect ratio (i.e., the outer diameter of the billet is much smaller than the inner diameter of the die cavity) are usually required. In this case, problems such as billet instability and uneven filling due to difficulty in billet alignment are likely to occur. Although multi-step forging (CN202421589129.6, CN202211581707.7) can improve the above defects, it also increases the difficulty of on-site operation, affects production efficiency, and cannot effectively solve the problem of uneven billet filling. Summary of the Invention

[0005] This invention discloses a forging die and forging method for metal disc-shaped parts, in order to solve any of the above-mentioned and other potential problems in the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a forging die for metal disc-shaped parts, the forging die comprising: an upper die unit and a lower die unit; The lower die unit includes a lower die base, the bottom of which is connected to the lower anvil of the forging press. A lower die cavity is provided at the center of the top of the lower die base, and an annular groove is provided around the lower die cavity. The upper die unit includes an inner pressure head and an outer pressure head. One end of the inner pressure head is connected to the anvil plate on the forging press, and the other end is provided with a T-shaped pressure head. The outer pressure head has a cylindrical cavity at its center for placing the blank, and the bottom of the outer pressure head has an upper mold cavity that is the same as the lower mold cavity. The T-shaped pressure head is placed inside the cylindrical cavity.

[0007] Furthermore, the end of the T-shaped pressure head also includes a limiting protrusion, the shape of which is the same as the end face shape of the metal disc-like part to be formed.

[0008] Furthermore, the materials of the upper mold unit and the lower mold unit include mold steel and high-temperature alloy.

[0009] Another object of the present invention is to provide a method for forging metal disc-shaped parts using the forging die described above. The forging method uses the volume of the metal disc-shaped part to be formed as a reference to determine the height-to-diameter ratio of the cylindrical blank, then places the cylindrical blank in the cavity of the die, and adopts a step-by-step forging method to first form the central part of the metal disc-shaped forging, and then form the edge part of the metal disc-shaped forging, thereby obtaining the metal disc-shaped part.

[0010] Furthermore, the forging method specifically includes the following steps: S1) Based on the volume of the metal disc-like part to be formed, determine the height-to-diameter ratio of the cylindrical blank and prepare the cylindrical blank. S2) The cylindrical blank and forging die obtained in S1) are heated to the temperature required for forging, and then the cylindrical blank is placed in the cavity of the die, wherein one end of the blank protrudes out of the cavity and contacts the bottom of the lower die cavity; S3) Start the forging machine. The upper anvil of the forging machine drives the inner pressure head to press down. The billet is compressed and undergoes radial plastic deformation. According to the "law of least resistance", the billet pushes the outer pressure head upward while filling the cavity until it is at the same height as the upper end face of the inner pressure head. The upper anvil of the forging machine continues to press down, pressing the outer pressure head and the inner pressure head down to the mold closing at the same time, thus completing the forging. S4) The upper anvil of the forging machine is lifted, and the inner pressure head and the outer pressure head are lifted in sequence to complete the demolding and take out the forging, thus obtaining a metal disc-shaped part.

[0011] Furthermore, the height-to-diameter ratio of the billet in S1) is 1.3~2.

[0012] Furthermore, the horizontal projection diameter of the inner pressure head in S2) is the same as the diameter of the billet.

[0013] Furthermore, in S2), the height of the protruding portion of the blank is equal to the height of the formed metal disc-like part, and less than the overall height of the blank.

[0014] A metal disc-shaped component, which is prepared by the forging method described above.

[0015] Advantages of this invention: This invention provides a novel forging method for metal disc-shaped parts. This method can reduce the maximum load required for forging, eliminate the pre-forging step or complex initial machining steps, facilitate demolding, increase the deformation of the forging, and improve the strength, plasticity, and performance consistency of the forging product. Compared with the prior art, this invention has the following beneficial effects: This invention eliminates the pre-forging step, allowing large aspect ratio billets to be formed into small aspect ratio disc-shaped parts in a single forging step, which can effectively improve production efficiency.

[0016] The maximum forging load of this invention is only 40-65% of that of conventional methods, and the forging energy consumption is significantly reduced.

[0017] The deformation of the forgings produced by this invention is significantly better than that of conventional methods, and the average strain of the forgings is 6 to 10 times that of conventional methods.

[0018] This invention employs constrained centering of the billet, effectively avoiding uneven filling caused by billet position displacement during forging, while also preventing the instability problem of billets with large height-to-diameter ratios. Attached Figure Description

[0019] Figure 1 This is an assembly diagram of a forging die for a metal disc-shaped part according to the present invention.

[0020] Figure 2 This is a schematic flowchart of a forging method for a metal disc-shaped part according to the present invention.

[0021] Figure 3 This is a schematic diagram of the assembly of a forging die according to another embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram comparing the equivalent strain field distribution of forging cross sections under the same conditions using conventional forging methods and the forging method of this invention (for billet 970). o C, Mold 300 o C. Forging speed 100 mm / s); (a) is a conventional forging method; (b) is the forging method of the present invention.

[0023] Figure 5 This is a schematic diagram comparing the loads under the same forging conditions of conventional forging methods and the forging method of the present invention.

[0024] Figure 6 This is a schematic diagram comparing the load under the same forging efficiency of conventional forging methods and the forging method of this invention; (Conventional forging method: billet 970) o C, Mold 300 oC. Forging speed 100 mm / s; Forging method of this invention: billet 970 o C, Mold 300 o C. Forging speed 300 mm / s).

[0025] In the picture: 1. Upper anvil of the forging machine, 2. Lower anvil of the forging machine, 3. Upper die unit, 3-1. Inner pressure head, 3-2. Outer pressure head, 3-3. Cylindrical cavity, 3-4. Upper die cavity, 4. Lower die unit, 4-1. Lower die base, 4-2. Lower die cavity, 4-3. Annular groove, 5. Limiting protrusion, 6. Billet. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0027] like Figure 1 As shown, the present invention provides a forging die for a metal disc-shaped part, the forging die comprising: an upper die unit 3 and a lower die unit 4; The lower die unit 4 includes a lower die base 4-1. The bottom of the lower die base 3 is connected to the lower anvil plate 2 of the forging press. The lower die base 4-1 has a lower die cavity 4-2 at the center of its top. The lower die cavity 4-2 has an annular groove 4-3 around its perimeter. The upper die unit 3 includes an inner pressure head 3-1 and an outer pressure head 3-2. One end of the inner pressure head 3-1 is connected to the anvil plate 1 of the forging press, and the other end is provided with a T-shaped pressure head. The outer pressure head 3-2 has a cylindrical cavity 3-3 at its center for placing the blank. The bottom of the outer pressure head 3-2 has an upper mold cavity 3-4 that is formed to fit with the lower mold cavity 4-2. The upper mold cavity 3-4 is connected to the cavity 3-3. The T-shaped pressure head is placed inside the cylindrical cavity 3-3 and moves up and down inside the cylindrical cavity 3-3 under the drive of the inner pressure head 3-1.

[0028] Furthermore, the end of the T-shaped pressure head also includes a limiting protrusion 5, the shape of which is the same as the end face shape of the metal disc-like part to be formed, in order to prevent the blank from shifting.

[0029] Furthermore, the materials of the upper mold unit 3 and the lower mold unit 4 include mold steel and high-temperature alloy.

[0030] Furthermore, the end of the T-shaped pressure head also includes a limiting protrusion, the shape of which is the same as the end face shape of the metal disc-like part to be formed, such as... Figure 3 As shown.

[0031] Example: The chemical composition of the Ti60 alloy ingots used in the forging experiment is shown in Table 1 (unit: wt%).

[0032] Table 1 Chemical composition of Ti60 alloy In this embodiment, the forging weighs 231 kg, the blank weight is 249 kg, the maximum outer dimensions of the forging (billet) are φ750×190 mm, and the horizontal projected area of ​​the forging is 0.44 m². 2 .

[0033] Step 1: Using the forging method of this invention, the mold and the blank are as follows... Figure 1 As shown, the upper anvil 1 and inner pressure head 3-1 of the forging press are connected by bolts, and the lower die base 4-1 and lower anvil 2 of the forging press are connected by bolts. During the assembly process, the inner pressure head 3-1 and outer pressure head 3-2 are installed sequentially from bottom to top, and the inner pressure head 3-1, outer pressure head 3-2, and lower die base 4-1 are preheated to 300°C. o C, billet 6 is heated in the furnace to 970°C. o After being heated for 30 minutes, the blank 6 is placed on the lower mold base 4-1; the height-to-diameter ratio of the blank 6 is 1.6, the diameter of the blank 6 is 360mm, and the horizontal projection diameter of the inner pressure head is 360mm.

[0034] Step 2: Place the cylindrical blank into the cavity of the mold, with one end of the blank protruding outside the cavity and contacting the bottom of the lower mold cavity, or place the blank inside the lower mold cavity. The anvil 1 on the forging machine drives the inner pressure head 3-1 to press down, causing the bottom of the outer pressure head 3-2 to engage in the annular groove 4-3, restricting the lateral displacement of the outer pressure head 3-2. The blank 6 undergoes radial plastic deformation under compression. According to the "law of least resistance" (during deformation, when a metal particle has the possibility of moving in any direction, it moves in the direction of least resistance), the blank 6 fills the cavity while simultaneously pushing the outer pressure head 3-2 upward until it is at the same height as the upper end face of the inner pressure head 3-1. Figure 2 As shown in (b); Step 3: The anvil 1 on the forging machine continues to press down, simultaneously pressing the outer pressure head 3-2 and the inner pressure head 3-1 down until the mold closes. Figure 2 (c) shows the completed forging process; Step 4: Lift the anvil 1 on the forging machine, and lift the inner pressure head 3-1 and the outer pressure head 3-2 in sequence, as follows. Figure 2 As shown in (d), demolding and removal of the forging are completed.

[0035] For comparison, this invention provides a conventional forging method in which the billet needs to be machined into a cylindrical blank with grooved positioning. During the forging process, the upper die, positioning sleeve, and lower die are preheated to 300°C. o C, billet 4 is heated in the furnace to 970°C. oAfter holding at temperature for 30 minutes, place it on the lower mold. The forging steps are as follows: Step 1: The anvil on the forging machine drives the upper die to press down until it is fully closed; Step 2: The anvil on the forging machine is lifted, which drives the upper die to be lifted, completing the demolding. The positioning sleeve is removed by the clamp and the forging is taken out.

[0036] Finite element simulation was used to obtain the equivalent strain distribution of the present invention and the conventional forging method, as shown below. Figure 4 and Figure 5 As shown, the forging method of the present invention can enable the forging to obtain greater plastic deformation, and the average strain of the forging is 6 to 10 times that of conventional methods.

[0037] Finite element analysis was used to obtain the forging load-displacement curves of the present invention and conventional forging methods (with the same forging speed), as shown below. Figure 5 As shown, the maximum load of the forging method described in this invention is significantly reduced, to only 65.1% of that of conventional methods. Specifically, the horizontal forging load in the forging method of this invention is approximately 4500 tons, and the forging rate is 0.42 s. -1 At this stage, the surface temperature of the billet is approximately 800°C. o C.

[0038] Finite element analysis was used to obtain the forging load-time curves (for the same forging time) of the present invention and conventional forging methods, as shown below. Figure 6 As shown, the forging method of the present invention also significantly reduces the maximum forging load, which is only 41.5% of that of conventional methods. Specifically, the horizontal forging load in the forging method of the present invention is approximately 3500 tons, and the forging rate is 1.25 s. -1 At this stage, the surface temperature of the billet is approximately 950°C. o C.

[0039] The forging die and forging method for a metal disc-shaped part provided in the embodiments of this application have been described in detail above. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this application; at the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this application. Therefore, the content of this specification should not be construed as a limitation of this application.

[0040] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0041] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0042] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0043] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A forging die for a metal disc-shaped part, the forging die comprising: Upper mold unit and lower mold unit; The lower die unit includes a lower die base, the bottom of which is connected to the lower anvil of the forging press. A lower die cavity is provided at the center of the top of the lower die base, and an annular groove is provided around the lower die cavity. The upper die unit is characterized in that it includes an inner pressure head and an outer pressure head, one end of the inner pressure head is connected to the anvil plate of the forging press, and the other end is provided with a T-shaped pressure head; The outer pressure head has a cylindrical cavity at its center for placing the blank, and an upper mold cavity at its bottom that mates with the lower mold cavity. The T-shaped pressure head is placed inside the cylindrical cavity.

2. The forging die according to claim 1, characterized in that, The end of the T-shaped pressure head also includes a limiting protrusion, the shape of which is the same as the end face shape of the metal disc-like part to be formed.

3. The forging die according to claim 1 or 2, characterized in that, The upper and lower mold units are made of mold steel and high-temperature alloys.

4. A method for forging metal disc-shaped parts using the forging die as described in claim 1, characterized in that, The forging method uses the volume of the metal disc-shaped part to be formed as a reference to determine the height-to-diameter ratio of the cylindrical blank. Then, the cylindrical blank is placed in the cavity of the mold, and a step-by-step forging method is adopted to first form the central part of the metal disc-shaped forging, and then form the edge part of the metal disc-shaped forging, thus obtaining the metal disc-shaped part.

5. The method according to claim 4, characterized in that, The forging method specifically includes the following steps: S1) Based on the volume of the metal disc-like part to be formed, determine the height-to-diameter ratio of the cylindrical blank and prepare the cylindrical blank. S2) The cylindrical blank and forging die obtained in S1) are heated to the temperature required for forging, and then the cylindrical blank is placed in the cavity of the die, wherein one end of the blank protrudes out of the cavity and contacts the bottom of the lower die cavity; S3) Start the forging machine. The upper anvil of the forging machine drives the inner pressure head to press down. The billet is compressed and undergoes radial plastic deformation. According to the "law of least resistance", the billet pushes the outer pressure head upward while filling the cavity until it is at the same height as the upper end face of the inner pressure head. The upper anvil of the forging machine continues to press down, pressing the outer pressure head and the inner pressure head down to the mold closing at the same time, thus completing the forging. S4) The upper anvil of the forging machine is lifted, and the inner pressure head and the outer pressure head are lifted in sequence to complete the demolding and take out the forging, thus obtaining a metal disc-shaped part.

6. The method according to claim 5, characterized in that, The height-to-diameter ratio of the blank in S1) is 1.3~2.

7. The method according to claim 5, characterized in that, The horizontal projection diameter of the internal pressure head in S2) is the same as the diameter of the billet.

8. The method according to claim 5, characterized in that, The height of the protruding part of the blank in S2) is equal to the height of the formed metal disc-like part, and less than the overall height of the blank.

9. A metal disc-like component, characterized in that, The metal disc-like component is prepared by the method described in any one of claims 4-8.

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