Forging forming method and extrusion broaching device for titanium alloy integral frame forge piece
By using extrusion expansion devices and numerical simulation design methods, the problem of insufficient expansion capacity of extra-large titanium alloy integral frame forgings was solved, enabling rapid expansion and low-cost production, and reducing equipment load and processing costs.
Patent Information
- Application Number
- CN202511830621.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-06
- Publication Date
- 2026-01-23
AI Technical Summary
Existing technologies have limited capacity for widening of extra-large titanium alloy integral frame forgings, require multiple forging processes, have long production cycles, and incur high production and processing costs.
An extrusion and expansion device is used to extrude and expand the pores and thin the intermediate skin by contacting the billet with an elliptical punch. The initial and final billet specifications are determined by numerical simulation design. 5CrNiMo material and a device with a preheating temperature of 300-400℃ are used. The design of the bevel and fillet is optimized to avoid tearing and achieve rapid expansion of the billet.
It improves the billet's ability to expand, reduces the equipment's forming load, lowers production costs, shortens the production cycle, and breaks through the equipment's maximum load limit.
Smart Images
Figure CN121373264A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of large-scale die forging, and particularly relates to a forging forming method of a titanium alloy integral frame forging and an extrusion hole expanding device. BACKGROUND
[0002] With the continuous improvement of forging and pressing equipment capacity in the field of aviation, the rated load of large-scale forging and pressing equipment gradually develops from 20,000 tons, 30,000 tons to more than 50,000 tons. Consequently, aircraft parts also gradually tend to be large-scale and integrated design. The super-large die forging usually refers to a forging with a projection area of more than 2.5 m2. Due to the large projection area, the metal material deformation resistance increases sharply during forging, especially for the super-large integral frame with high ribs and thin webs, which tests the limit load of the forging and pressing equipment. Limited equipment capacity often cannot meet the load bottleneck of die forging forming. According to the structural characteristics of the super-large titanium alloy integral frame forging, the size of the blank and the forming characteristics of the oil press, the blank is farthest from the cavity in the width direction during die forging. Therefore, the spreading capacity is one of the most important links for testing the limit load of the equipment and the forming method.
[0003] In order to reduce the die forging forming pressure, the traditional forging process method often adopts “blanking + pre-forging + die forging”. The spreading capacity of the blank is limited, the forging times are many, and the production cycle is long. Moreover, the contour size of the integral frame forging is 3700 mm x 1700 mm x 140 mm (length x width x height), the pre-forming single block module size reaches 4500 mm x 2800 mm x 400 mm (length x width x height), and the module is 2 blocks, which also greatly increases the production and processing cost.
[0004] In summary, for the forging forming of the super-large titanium alloy integral frame, the main difficulty is how to effectively improve the spreading capacity of the blank, so that the blank can fully cover the die cavity as much as possible, and then ensure the die forging forming. SUMMARY
[0005] In order to solve the problems of limited spreading capacity, many forging times, long production cycle and high production and processing cost in the prior art, the application provides a forging forming method of a super-large titanium alloy integral frame and an extrusion hole expanding device, which effectively improves the spreading capacity of the blank, so that the blank can fully cover the die cavity as much as possible, and the super-large titanium alloy integral frame is forged, while the production investment cost is reduced. It can be used for the super-large titanium alloy integral frame forging.
[0006] The technical scheme is as follows: In a first aspect, an extrusion hole expanding device is provided, which is composed of three parts: two symmetrically distributed elliptical punches 11 and an intermediate connecting web plate 12, The elliptical punch 11 is a "convex" structure, which is composed of a small elliptical surface, a large elliptical surface and a transition surface with an inclination alpha, and the surfaces are smoothly and gently connected by large round angles R1 and R2. The elliptical punch 11 is used for contacting with the blank, and is used for extruding and expanding the intermediate skin of the blank; when the blank is pressed by the extruding and expanding device 1, the blank skin 21 is continuously extruded between the elliptical punch 11 and the lower die punch 32 of the forged piece, and the blank skin 21 is continuously thinned and expanded, so that the blank is rapidly expanded to the surrounding cavity.
[0007] Further, in order to improve the extruding and expanding capacity and avoid tearing and scratching the surface of the blank during the extruding and expanding process, the inclination alpha of the extruding and expanding device 1 is 167°, R1 is greater than or equal to R1 20mm, R2 is greater than or equal to R2 50mm, and the roughness of the working surface should be less than or equal to Ra 3.2.
[0008] In the elliptical punch 11, the length L1 of the long axis and the length L2 of the short axis satisfy L1>L2, and are mainly used for realizing the width expansion of the blank.
[0009] In order to improve the structural strength, the material of the extruding and expanding device 1 is 5CrNiMo, and the heat treatment hardness is HRC: 38-42; in order to make the extruding and expanding device work normally and avoid tearing the surface of the blank during the extruding and expanding process, the preheating temperature of the extruding and expanding device 1 is 300-400℃, and preferably 350℃.
[0010] The main advantage of the extruding and expanding device 1 is that the blank expansion capacity is effectively improved, the blank is rapidly expanded and covers the entire cavity, and the forming load of the equipment during forging is effectively reduced. When the extruding and expanding device 1 extrudes and expands the intermediate skin of the blank, the small elliptical surface of the elliptical punch 11 first contacts the blank, the contact area is small, the deformation resistance of the metal material is small, the skin 21 is gradually thinned, the small elliptical surface is gradually transitioned to the transition surface with an inclination alpha, the skin 21 is continuously extruded and expanded to the surrounding cavity in the form of extruding and expanding, especially in the width direction, so that the blank expansion efficiency is greatly improved, the blank is rapidly covered to the entire cavity profile, and a powerful guarantee is provided for die forging.
[0011] In a second aspect, a forging forming method of a titanium alloy integral frame forging piece is provided, and the extruding and expanding device of any one of the first aspect is used, and the device comprises the following steps: Step one, determining the initial blank size and the final rough blank size required for die forging: Step two, chamfering the four corners of the initial blank in a diagonal chamfering manner on a large free forging press; Step three, on a large free forging press, the initial blank is divided and drawn to make the final rough blank required for die forging; Step four, on a large die forging press, the flat die and the extrusion hole expanding device are used as the upper die, and the forging lower die is used as the lower die, the extrusion hole expanding and thinning intermediate skin of the final rough blank is carried out, the skin material is extruded and flowed into the surrounding cavity, so that the blank is rapidly expanded; after forging, part of the skin of the blank is cut off, and the subsequent forming load is reduced; Step five, repeat step four, on a large die forging press, the flat die and the extrusion hole expanding device are used as the upper die, and the forging lower die is used as the lower die, the extrusion hole expanding and thinning intermediate skin of the blank is continued, the skin material is continued to be extruded and flowed into the surrounding cavity, so that the blank is continuously expanded and covers the entire lower die cavity profile; after forging, most of the skin of the blank is cut off, and the subsequent forming load is further reduced; Step six, on a large die forging press, the upper and lower dies of the forging are used to press the blank to form a complete cavity, and the forging is completed.
[0012] In step one, according to the structure characteristics of the large titanium alloy integral frame forging, combined with numerical simulation, from the perspective of random design and simple design in the field of forging, the final rough blank required for die forging of the large titanium alloy integral frame forging is determined, which can meet the requirements of die forging forming, cross-section material, deformation of each part, etc.; according to the principle of equal volume of metal material, the initial blank is determined as a rectangular plate blank; The size of the initial blank and the final rough blank needs to ensure that the volume V 初 of the initial blank is the same as the volume V 终 of the final rough blank, that is, V 初 =V 终 ; and the full process of the application needs to be verified by numerical simulation, and each part of the final rough blank needs to completely fill the die cavity.
[0013] In step two, in order to avoid folding or pinching when the initial blank is diagonally chamfered, the amount of each hammering is ≤30mm; the speed of each hammering is ≤10mm / s; and the final forging temperature is ≥850℃.
[0014] In step three, in order to ensure the organization and performance of the titanium alloy forging, when the initial blank is divided and drawn, the amount of each hammering is ≤20mm; the speed of each hammering is ≤10mm / s; and the final forging temperature is ≥800℃.
[0015] The beneficial effects are: For extra-large titanium alloy integral frame forgings, an extrusion reaming device and forging method are used. Under limited equipment load, the extrusion reaming device extrudes and thins the connecting skin of the billet, achieving the purpose of reaming and billet widening. By cutting the connecting skin twice, the projected area of the billet and the deformation resistance of the forging are reduced, effectively reducing the forming load on the equipment during forging. This allows the billet to quickly cover the entire die cavity, significantly improving the widening capacity of the equipment and effectively ensuring die forging. This invention overcomes the maximum load limit of the equipment, saves the investment cost of a pre-forging die for extra-large forgings, and achieves the goal of "small equipment, small investment, big work". Attached Figure Description
[0016] Figure 1(a) is a front view of the extrusion and expansion device in this invention; Figure 1(b) is a top view of the extrusion and expansion device in this invention; Figure 2 This is the AA section view of Figure 1(b); Figure 3 This is a schematic diagram of the lower die of the extra-large titanium alloy integral frame forging in this invention; Figure 4 This is a schematic diagram showing the placement of the extrusion and expansion device and the final blank in the lower die of the forging. Figure 5 yes Figure 4 BB section view; Figure 6 This is a forging flowchart of the forging forming method of the present invention; Among them, 1. extrusion and expansion device, 11. elliptical punch, 12. intermediate connecting web, 2. final blank, 21. connecting skin, 3. lower die, 31. lower die cavity, 32. lower die punch. Detailed Implementation
[0017] This invention designs an extrusion reaming device 1 for extra-large titanium alloy integral frame forgings. The extrusion reaming device 1 consists of three parts: two symmetrically distributed elliptical punches 11 and a central connecting web plate 12. See Figures 1(a) and 1(b). Figure 2 .
[0018] The elliptical punch 11 has a convex structure, consisting of a small elliptical surface, a large elliptical surface, and a transition surface with a certain slope α. The surfaces are smoothly transitioned with large rounded corners R1 and R2. The elliptical punch 11 is the main working part of the extrusion and reaming device 1. The elliptical convex surface is used to contact the billet, extruding and reaming the billet and thinning the intermediate connecting skin. When the extrusion and reaming device 1 presses the billet, the billet connecting skin 21 is continuously squeezed between the elliptical punch 11 and the forging lower die punch 32. By continuously thinning and reaming the billet connecting skin 21, the billet is rapidly widened to the surrounding cavity.
[0019] Preferably, in order to improve the extrusion hole expansion capacity, avoid the tearing and pinching of the blank surface during the extrusion hole expansion process, the extrusion hole expansion device 1 is optimized in parameters, such as Figure 2 As shown in the figure, the slope α = 167°, R1≥R120mm, R2≥R50mm, and the roughness of the working surface should be ≤Ra3.2.
[0020] The elliptical punch 11 has specific requirements for the long axis size L1 and the short axis size L2 of the ellipse, as shown in the figure, L1>L2 should be met, and it is mainly used for realizing the width direction expansion of the blank. The specific design size can be iteratively optimized according to numerical simulation. Figure 2
[0021] In order to improve the structural strength, the material of the extrusion hole expansion device 1 is 5CrNiMo, and the heat treatment hardness is HRC: 38-42; in order to make the extrusion hole expansion device work normally and avoid the tearing of the blank surface during the extrusion hole expansion process, the preheating temperature of the extrusion hole expansion device 1 is 300-400℃, preferably 350℃.
[0022] The main advantage of the extrusion hole expansion device 1 of the application is that the blank expansion capacity is effectively improved, the blank is rapidly expanded and covers the entire cavity, and the equipment forming load in the forging process is effectively reduced. When the extrusion hole expansion device 1 is used for extruding and expanding the blank and thinning the skin, the small elliptical surface of the elliptical punch 11 first contacts the blank, the contact area is small, the deformation resistance of the metal material is small, and the skin 21 is gradually thinned by continuously pressing down, and the small elliptical surface gradually transitions to the transition surface with the slope α. The material of the skin 21 is continuously extruded and expanded to the surrounding cavity in the form of extrusion hole expansion, especially in the width direction, thereby greatly improving the blank expansion efficiency, rapidly covering the blank to the entire cavity profile, and providing a strong guarantee for die forging forming.
[0023] The application provides a forging forming method of a large titanium alloy integral frame forging, and the method comprises the following steps: Step one, determining the initial blank size and the final rough blank size required for die forging: according to the structural characteristics of the large titanium alloy integral frame forging, combined with numerical simulation, considering the die forging field and simple design, the final rough blank size required for die forging is determined by selecting a size that can meet the requirements of die forging forming, cross section material, deformation of each part and the like of the large titanium alloy integral frame forging; according to the metal material equal volume principle, the initial blank is determined as a rectangular plate blank.
[0024] The size of the initial blank and the final rough blank needs to be ensured to be the same as the volume V 初 of the final rough blank, that is, V 终 =V 初 =V 终 And, the whole process of the application needs to be verified by numerical simulation, and finally each part of the rough blank needs to completely fill the mold cavity.
[0025] Step two, on the large free forging press, the four corners of the initial blank are chamfered in a diagonal chamfering manner.
[0026] In order to avoid folding or pinching when chamfering the initial blank, the amount of each hammering is ≤30mm, the speed of each hammering is ≤10mm / s, and the final forging temperature is ≥850℃.
[0027] Step three, on the large free forging press, the initial blank is divided and elongated to make the final rough blank required for die forging.
[0028] In order to ensure the organization and performance of titanium alloy forgings, the amount of each hammering is ≤20mm, the speed of each hammering is ≤10mm / s, and the final forging temperature is ≥800℃ when the initial blank is divided and elongated.
[0029] Step four, on the large die forging press, the flat die and the extrusion and hole expanding device are used as the upper die, and the forging lower die is used as the lower die, the extrusion and hole expanding device is used to extrude and expand the intermediate skin of the final rough blank and thin the intermediate skin, the material of the skin is extruded and flowed into the surrounding cavity, so that the blank is rapidly expanded; after forging, part of the skin of the blank is cut off, which can reduce the subsequent forming load.
[0030] Step five, repeat step four, on the large die forging press, the flat die and the extrusion and hole expanding device are used as the upper die, and the forging lower die is used as the lower die, the blank is continuously extruded and expanded, and the material of the skin is continuously extruded and flowed into the surrounding cavity, so that the blank is continuously expanded and covers the entire lower die cavity profile; after forging, most of the skin of the blank is cut off, which can further reduce the subsequent forming load.
[0031] Step six, on the large die forging press, the upper and lower dies of the forging are used to press and form the blank as a whole until the blank completely fills the cavity, and the forging is completed.
[0032] For example, the material of a certain large titanium alloy integral frame forging is TC4-DT titanium alloy, the contour size is 3700mmx1700mmx140mm (lengthxwidthxheight), and the overall projection area of the forging with skin is 5.1m 2 According to the structural characteristics of the forging, the overall contour of the forging is similar to a "glasses frame", the "lens" part corresponds to the lower die punch 32, the two sides of the "glasses frame" are provided with high ribs, and the overall contour of the forging is a high rib thin web structure.
[0033] Step one, according to the structure characteristics of the forging and the numerical simulation iterative optimization, the final rough blank 2 of the forging is determined as a rectangular blank with simple high bosses at both ends from the aspects of random design and simple design. According to the isometric principle of metal material hot working, the initial blank is determined as a rectangular blank with equal cross-sectional dimensions, and the size specification is 2340mm*1350mm*130mm (length*width*height).
[0034] Step two, the four corners of the initial blank (rectangular blank) are chamfered in a diagonal chamfering manner on a large free forging press, and the forging is completed in one heating.
[0035] Step three, the initial blank is precisely divided and lengthened on a large free forging press, and the initial blank (rectangular blank) is forged into the final rough blank 2 required for die forging. Preferably, according to the forging deformation (15%-30%) and temperature field (T≥800℃) control requirements of TC4-DT titanium alloy, the forging heating is 3 times.
[0036] Step four, the final rough blank 2 is extruded and expanded and the intermediate skin 21 is thinned on a large die forging press by using a flat die + extrusion expansion device 1 as the upper die and a lower die 3 as the lower die, the material of the skin 21 is extruded and flowed into the surrounding cavity, so that the blank is rapidly expanded. The forging is completed in one heating. Preferably, according to the numerical simulation forming and load, the Φ550 round core material is cut off at the skin 21 after forging.
[0037] Step five, repeat step four, continue to extrude and expand the blank and thin the intermediate skin 21 on a large die forging press by using a flat die + extrusion expansion device 1 as the upper die and a lower die 3 as the lower die, continue to extrude and flow the material of the skin 21 into the surrounding cavity, so that the blank continues to expand and covers the entire lower die cavity profile. The forging is completed in one heating. Preferably, according to the numerical simulation forming and load, the large elliptical core material is cut off at the skin 21 after forging, and the size of the large ellipse is the same as that of the large ellipse of the elliptical punch 11.
[0038] Step six, the blank is integrally pressed and formed on a large die forging press by using the upper and lower dies of the forging, until the blank completely fills the cavity, and the forging is completed. The forging is completed in one heating.
[0039] The above only expresses the embodiments of the present application, which are described in detail and in detail, but cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. In addition, the parts of the present application not described in detail are conventional techniques.
Claims
1. An extrusion underreaming apparatus, comprising: The extrusion hole expanding device is composed of three parts: two symmetrically distributed elliptical punches and an intermediate connecting web, The elliptical punch is a "convex" structure composed of a small elliptical surface, a large elliptical surface and a transition surface with an inclination α, and the surfaces are smoothly and smoothly connected by large round corners R1 and R2. The elliptical convex surface of the elliptical punch is used to contact the blank, and the intermediate skin of the blank is extruded and thinned; when the extrusion hole expanding device is used to press the blank, the blank skin is continuously extruded between the elliptical punch and the lower die punch of the forging, and the blank is rapidly expanded to the surrounding cavity by continuously thinning and expanding the blank skin.
2. The apparatus of claim 1, wherein, The inclination α of the extrusion hole expanding device is 167°, R1≥R120mm, R2≥R50mm, and the roughness of the working surface should be ≤Ra3.
2.
3. The apparatus of claim 1, wherein, The elliptical long axis size L1 and the short axis size L2 of the elliptical punch satisfy: L1>L2.
4. The apparatus of claim 1, wherein, The material of the extrusion hole expanding device is 5CrNiMo, and the heat treatment hardness is HRC: 38-42; the preheating temperature of the extrusion hole expanding device during use is 300-400℃.
5. A method of forging forming a titanium alloy monoblock frame forging, characterized by, The extrusion hole expanding device of any one of claims 1 to 4 comprises the following steps: Step one, determine the initial blank size and the final rough blank size required for die forging: Step two, on a large free forging press, the four corners of the initial blank are chamfered in a diagonal chamfering manner; Step three, on a large free forging press, the initial blank is divided and lengthened to make the final rough blank required for die forging; Step four, on a large die forging press, the flat die and the extrusion hole expanding device are used as the upper die, and the forging lower die is used as the lower die, and the extrusion hole expanding device is used to extrude and thin the intermediate skin of the final rough blank, and the skin material is extruded into the surrounding cavity, so that the blank is rapidly expanded; after forging, part of the skin of the blank is cut off to reduce the subsequent forming load; Step five, repeat step four, on a large die forging press, the flat die and the extrusion hole expanding device are used as the upper die, and the forging lower die is used as the lower die, and the extrusion hole expanding device is used to continue to extrude and thin the intermediate skin of the blank, and the skin material is continuously extruded into the surrounding cavity, so that the blank continues to expand and covers the entire lower die cavity profile; after forging, most of the skin of the blank is cut off to further reduce the subsequent forming load; Step six, on a large die forging press, the upper and lower dies of the forging are used to press the blank to form a complete cavity, and the forging is completed.
6. The method of claim 5, wherein, In step one, according to the structure characteristics of the large titanium alloy integral frame forging, considering the random design and simple design in the field of forging, the final rough blank size required for die forging, cross section material and deformation amount of each part are determined; according to the principle of equal volume of metal materials, the initial blank is determined as a rectangular plate; In designing the dimensions of the initial billet and the final rough billet, the volume V 初 of the initial billet is made the same as the volume V 终 of the final rough billet, i.e. V 初 = V 终 .
7. The method of claim 5, wherein, In step two, the hammering amount is ≤30mm, the hammering speed is ≤10mm / s, and the final forging temperature is ≥850℃.
8. The method of claim 5, wherein, In step three, when the initial blank is divided and lengthened, the hammering amount is ≤20mm, the hammering speed is ≤10mm / s, and the final forging temperature is ≥800℃.