Manufacturing method for improving the tensile properties of aluminum alloy ring forgings and the resulting aluminum alloy ring forgings.

Abstract

This invention relates to the field of forging technology, and in particular to a manufacturing method for improving the tensile properties of aluminum alloy ring forgings and the resulting aluminum alloy ring forgings. The manufacturing method for improving the tensile properties of aluminum alloy ring forgings includes the following steps: (a) pre-rolling a heat-treated aluminum alloy ring billet to obtain a pre-rolled ring billet; in the pre-rolling process, keeping the outer diameter of the ring billet constant, radial pressure is applied along the inner wall of the ring billet to increase its height; (b) subjecting the pre-rolled ring billet to height reduction deformation to obtain a ring forging; in the height reduction deformation, keeping the outer diameter of the pre-rolled ring billet constant, axial pressure is applied to the pre-rolled ring billet to decrease its inner diameter. The manufacturing method of this invention, while ensuring or even improving the tangential mechanical properties of the ring forgings, significantly improves the radial and vertical mechanical properties of the ring forgings, breaking through the bottleneck of existing ring forging rolling technology.

Description

Technical Field

[0001] This invention relates to the field of forging technology, and in particular to a manufacturing method for improving the tensile properties of aluminum alloy ring forgings and the resulting aluminum alloy ring forgings. Background Technology

[0002] Due to their high specific strength and lightweight properties, aluminum alloy ring forgings are widely used in high-tech fields such as aerospace and precision machinery equipment.

[0003] The current forming method for aluminum alloy ring forgings is: bar stock heating → billet preparation (upsetting, punching) → heating → rolling. When rolling ring forgings, if... Figure 1 As shown, the main deformation direction is the circumferential direction, while the radial and vertical directions of the ring are the secondary deformation directions. Furthermore, the rolling forming is based on hole expansion deformation, which is an irreversible forming process in which the outer diameter is continuously expanded. This process cannot fundamentally reduce the anisotropy of mechanical properties, resulting in significant differences in the three-dimensional mechanical properties of the forging.

[0004] With the development of aluminum alloys, the requirements for the comprehensive mechanical properties of aluminum alloy products have become increasingly stringent. Ring forgings obtained using existing forming methods are prone to failing to meet the required radial and vertical mechanical properties.

[0005] Therefore, in order to meet the design performance requirements of ring forgings, it is of great significance to ensure the tangential mechanical properties of ring forgings while improving their radial and vertical mechanical properties under the conditions of existing equipment and limited production resources.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] One object of the present invention is to provide a manufacturing method for improving the tensile properties of aluminum alloy ring forgings, so as to solve the technical problems in the prior art, such as the inability of the radial and vertical mechanical properties of aluminum alloy ring forgings to meet the performance requirements.

[0008] Another object of the present invention is to provide an aluminum alloy ring forging prepared by the above-described manufacturing method.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] A manufacturing method for improving the tensile properties of aluminum alloy ring forgings includes the following steps:

[0011] (a) The heat-treated aluminum alloy ring billet is pre-rolled to obtain a pre-rolled ring billet; in the pre-rolling process, the outer diameter of the ring billet is kept constant, and radial pressure is applied along the inner wall of the ring billet to increase the height of the ring billet.

[0012] (b) The pre-rolled ring blank is subjected to high-pressure deformation to obtain a ring forging; during the high-pressure deformation, the outer diameter of the pre-rolled ring blank is kept constant, and axial pressure is applied to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank.

[0013] In a specific embodiment of the present invention, steps (a) and (b) are repeated 1 to 5 times.

[0014] In a specific embodiment of the present invention, in step (a), the temperature of the heat treatment is 420-470°C; and the time of the heat treatment is 1.5-15 hours.

[0015] In a specific embodiment of the present invention, in step (a), the height of the pre-rolled ring billet is 1.2 to 1.55 times the height of the aluminum alloy ring billet.

[0016] In a specific embodiment of the present invention, in step (b), the deformation amount of the height compression deformation is 20% to 55%.

[0017] In a specific embodiment of the present invention, in step (b), the inner diameter of the ring forging after the height is reduced and deformed is the same as the inner diameter of the ring blank; the height of the ring forging is the same as the height of the ring blank.

[0018] In a specific embodiment of the present invention, step (a) involves maintaining the outer diameter of the ring blank unchanged by: using an annular outer mold sleeve fitted over the ring blank; the inner diameter of the annular outer mold sleeve is the same as the outer diameter of the ring blank. Further, the height of the annular outer mold sleeve is greater than or equal to the height of the pre-rolled ring blank after pre-rolling.

[0019] In a specific embodiment of the present invention, step (b) of maintaining the outer diameter of the pre-rolled ring billet unchanged includes: using an annular outer mold sleeve fitted over the pre-rolled ring billet; the inner diameter of the annular outer mold sleeve is the same as the outer diameter of the pre-rolled ring billet. Further, the height of the annular outer mold sleeve is greater than or equal to the height of the pre-rolled ring billet.

[0020] In practice, the same outer mold sleeve can be used in steps (a) and (b).

[0021] In a specific embodiment of the present invention, step (b), the method of applying axial pressure to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank includes: fitting an annular outer mold sleeve over the pre-rolled ring blank; placing and centering a mold core inside the pre-rolled ring blank; placing and centering a lower pressure pad ring on the pre-rolled ring blank; and applying axial pressure to the lower pressure pad ring. Further, the mold core is a cylindrical or annular structure; the diameter or outer diameter of the mold core is the same as the inner diameter of the ring blank; and the height of the mold core is the same as the height of the ring blank. The inner diameter of the lower pressure pad ring is the same as the inner diameter of the ring blank, and the outer diameter of the lower pressure pad ring is the same as the outer diameter of the ring blank; the height of the lower pressure pad ring is equal to the difference in height between the pre-rolled ring blank and the ring blank.

[0022] In a specific embodiment of the present invention, the method further includes: performing solution treatment and aging heat treatment on the ring forging.

[0023] In a specific embodiment of the present invention, step (a) involves the preparation of the aluminum alloy ring billet, which includes: heating the aluminum alloy bar billet, upsetting and punching it, and then heating and rolling it.

[0024] The present invention also provides an aluminum alloy ring forging obtained by any of the above-described methods for improving the tensile properties of aluminum alloy ring forgings.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) Through the pre-rolling process and the high-pressure deformation operation, the present invention can realize the repeated alternating deformation of the radial and vertical directions of the ring, and can also promote the tangential driven deformation. Although the outer diameter of the ring does not change, the structure of the ring becomes more uniform and dense after the forging ratio of the ring is reasonably increased. While the radial and vertical mechanical properties are significantly improved, the tangential mechanical properties can still be basically maintained without significant fluctuations, especially without reduction.

[0027] (2) The pre-rolling and high-pressure deformation processes used in the manufacturing method of this invention are completed through matching tooling, which can solidify the product deformation amount and facilitate standardized operation and high stability of process control. The product quality of ring forgings of the same specification has good consistency. In addition, the tooling design and assembly are simple, highly practical, and have low manufacturing costs. They are also reusable, resulting in good economic benefits. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 A schematic diagram of the finite element model for radial and axial rolling of aluminum alloy rings in existing technology;

[0030] Figure 2 This is a schematic diagram of the structure of the outer die sleeve used in the pre-rolling process provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the assembly structure of the outer die sleeve and the aluminum alloy ring billet in the pre-rolling process provided in an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the pre-rolled ring billet obtained after pre-rolling treatment according to an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the structure of the mold core used in the high-pressure deformation provided in the embodiments of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the pressure pad ring used in the high-pressure deformation provided in the embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the tooling mold assembly during high-pressure deformation provided in an embodiment of the present invention;

[0036] Figure 8 A schematic diagram of the assembly structure of the high-pressure deformation tooling and the pre-rolled ring billet provided in an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of the structure of the ring forging obtained after high-pressure deformation according to an embodiment of the present invention;

[0038] Figure 10 This is a heating curve diagram of step (1) in Embodiment 1 of the present invention;

[0039] Figure 11 This is a heating curve diagram of the two-stage solution treatment provided in Embodiment 1 of the present invention;

[0040] Figure 12 The heating curve diagram of the aging treatment provided in Embodiment 1 of the present invention.

[0041] Figure label:

[0042] 1-Aluminum alloy ring billet; 2-Outer die sleeve; 3-Pre-rolled ring billet;

[0043] 4-Die core; 5-Lower pressure pad ring; 6-Ring forging. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0045] In existing aluminum alloy ring forging methods, the primary deformation direction is the circumferential direction, while the radial and vertical directions are secondary deformation directions. Furthermore, rolling forming is based on hole expansion deformation, which fails to fundamentally reduce the anisotropy of mechanical properties, leading to significant differences in the three-dimensional mechanical properties of the forging. Currently, the tangential properties of the ring are relatively easy to guarantee, but the radial properties have a high risk of failure, and the vertical properties are even more prone to failure. Moreover, the compound phases in the alloy bar reduce the ability of the matrix to deform uniformly in different regions during forging. Increasing the deformation or increasing the forging ratio can improve the ability of the matrix to deform uniformly in different regions during forging, but current forming methods cannot achieve this.

[0046] This invention provides a manufacturing method for improving the tensile properties of aluminum alloy ring forgings, comprising the following steps:

[0047] (a) The heat-treated aluminum alloy ring billet is pre-rolled to obtain a pre-rolled ring billet; in the pre-rolling process, the outer diameter of the ring billet is kept constant, and radial pressure is applied along the inner wall of the ring billet to increase the height of the ring billet.

[0048] (b) The pre-rolled ring blank is subjected to high-pressure deformation to obtain a ring forging; during the high-pressure deformation, the outer diameter of the pre-rolled ring blank is kept constant, and axial pressure is applied to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank.

[0049] This invention limits and solidifies the outer diameter of the ring forging during rolling. During rolling, the ring wall thickness decreases, the inner diameter increases, and the radial direction becomes the primary deformation direction. Radial deformation causes the hot metal to flow towards the height direction, increasing the ring height and inducing subsequent deformation in the height direction. Simultaneously, by adding a height-down deformation process, the ring height decreases, making the height direction the primary deformation direction. Height deformation causes the hot metal to flow towards the radial direction, increasing the ring wall thickness and inducing subsequent radial deformation. Repeated radial and height deformation increases the amount of radial and height deformation, thereby enhancing the uniform deformation capacity of the matrix in all regions during the forging and rolling process. This reduces the anisotropy of the mechanical properties of the aluminum alloy ring forging, overcomes the bottleneck of rolling technology, and improves the radial and height tensile strength, yield strength, and plasticity of the forging. Specifically, the radial and height tensile strength and yield strength are increased by 8%–12%, and the radial and height plasticity (elongation after fracture) is increased by 30%–50%.

[0050] The manufacturing method of this invention can solve the fundamental problem of the extremely limited forging deformation space caused by the shape and structure of the ring. By using the final size of the ring after rolling as the initial size of this manufacturing method, and by fixing and limiting the outer diameter, the outer diameter of the ring will not increase during rolling, that is, the outer diameter remains almost constant, so that the material used for the ring remains unchanged and thermoplastic deformation can be achieved.

[0051] Furthermore, the manufacturing method of the present invention can be implemented using existing equipment, which is beneficial for large-scale application.

[0052] In a specific embodiment of the present invention, steps (a) and (b) are repeated. Further, steps (a) and (b) are repeated 1 to 5 times.

[0053] The manufacturing method of the present invention includes at least one set of (a) and (b). To further improve performance, the material can be repeatedly deformed in the radial and vertical directions, i.e., steps (a) and (b) can be repeated multiple times. (a) and (b) are a set, and each repetition of (a) and (b) is equivalent to performing (a) and (b) once. For example, the number of times steps (a) and (b) are repeated can be 1, 2, 3, 4, or 5 times, etc.

[0054] It should be noted that this does not limit the number of repetitions of steps (a) and (b) to no more than 5, but rather aims to balance material performance and processing efficiency. Performing steps (a) and (b) as a group, preferably in 2-3 groups, can significantly improve material performance while ensuring processing efficiency.

[0055] In a specific embodiment of the present invention, in step (a), the temperature of the heat treatment is 420-470°C; and the time of the heat treatment is 1.5-15 hours.

[0056] In different embodiments, the heating temperature in step (a) can be 420℃, 422℃, 425℃, 430℃, 435℃, 440℃, 445℃, 450℃, 455℃, 460℃, 465℃, 468℃, 470℃, etc., and the heating time can be 1.5h, 1.6h, 1.7h, 2h, 2.2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, etc.

[0057] In a specific embodiment of the present invention, in step (a), the height of the pre-rolled ring billet is 1.2 to 1.55 times the height of the aluminum alloy ring billet.

[0058] In different embodiments, in step (a), the height of the pre-rolled ring billet can be 1.2 times, 1.25 times, 1.3 times, 1.35 times, 1.4 times, 1.45 times, 1.55 times, etc., the height of the aluminum alloy ring billet. The height of the pre-rolled ring billet is within the above range to ensure more sufficient deformation in the height direction.

[0059] In a specific embodiment of the present invention, in step (a), the deformation amount of the pre-rolling treatment is 20% to 55%.

[0060] In different embodiments, in step (a), the deformation amount of the pre-rolling treatment can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, etc.

[0061] In a specific embodiment of the present invention, in step (b), the deformation amount of the height compression deformation is 20% to 55%.

[0062] In different implementations, in step (b), the deformation amount of the height-downward deformation can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, etc.

[0063] In a specific embodiment of the present invention, in step (b), the inner diameter of the ring forging after the height is reduced and deformed is the same as the inner diameter of the ring blank; the height of the ring forging is the same as the height of the ring blank.

[0064] By using high-pressure deformation, the dimensions of the ring forging are restored to match the initial dimensions of the aluminum alloy ring blank (i.e., the pre-designed ring dimensions). Therefore, although the pre-rolling process and high-pressure deformation are added, the radial and vertical deformation is significantly improved without changing the dimensions. This significantly improves the radial and vertical properties of the alloy while ensuring the tangential mechanical properties of the ring forging.

[0065] Furthermore, the addition of pre-rolling treatment and high-pressure deformation did not change the size of the ring, which is beneficial for production and product application.

[0066] In a specific embodiment of the present invention, step (a) involves maintaining the outer diameter of the ring blank unchanged by: using an annular outer mold sleeve fitted over the ring blank; the inner diameter of the annular outer mold sleeve is the same as the outer diameter of the ring blank. Further, the height of the annular outer mold sleeve is greater than or equal to the height of the pre-rolled ring blank after pre-rolling treatment, preferably the height of the annular outer mold sleeve is equal to the height of the pre-rolled ring blank after pre-rolling treatment.

[0067] In practice, an outer mold sleeve of the appropriate size can be designed according to the pre-required requirements.

[0068] In a specific embodiment of the present invention, step (b) of maintaining the outer diameter of the pre-rolled ring billet unchanged includes: using an annular outer mold sleeve fitted over the pre-rolled ring billet; the inner diameter of the annular outer mold sleeve is the same as the outer diameter of the pre-rolled ring billet. Further, the height of the annular outer mold sleeve is greater than or equal to the height of the pre-rolled ring billet, preferably equal to it.

[0069] In practice, the same outer mold sleeve can be used in steps (a) and (b).

[0070] In a specific embodiment of the present invention, step (b), the method of applying axial pressure to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank includes: fitting an annular outer mold sleeve over the pre-rolled ring blank; placing and centering a mold core inside the pre-rolled ring blank; placing and centering a lower pressure pad ring on the pre-rolled ring blank; and applying axial pressure to the lower pressure pad ring. Further, the mold core is a cylindrical or annular structure; the diameter or outer diameter of the mold core is the same as the inner diameter of the ring blank; and the height of the mold core is the same as the height of the ring blank. The inner diameter of the lower pressure pad ring is the same as the inner diameter of the ring blank, and the outer diameter of the lower pressure pad ring is the same as the outer diameter of the ring blank; the height of the lower pressure pad ring is equal to the difference in height between the pre-rolled ring blank and the ring blank.

[0071] In a specific embodiment of the present invention, the annular outer mold sleeve is a rigid outer mold sleeve. Rigidity means the ability to withstand loads that may be applied during the pre-rolling process and the high-pressure deformation process without deformation. For example, the material of the rigid outer mold sleeve can be ordinary structural steel or mold steel, such as 45 steel, 42CrMo, or 5CrNiMo, but is not limited to these. Furthermore, the wall thickness of the annular outer mold sleeve is 75–100 mm.

[0072] In a specific embodiment of the present invention, the mold core is a rigid mold core. The material of the rigid mold core can be ordinary structural steel or mold steel, such as 45 steel, 42CrMo, or 5CrNiMo.

[0073] In a specific embodiment of the present invention, the lower pressure pad ring is a rigid lower pressure pad ring. The material of the rigid lower pressure pad ring can be ordinary structural steel or mold steel, such as 45 steel, 42CrMo, or 5CrNiMo.

[0074] In practice, the pre-rolling process can be performed by rolling the ring billet using a horizontal radial-axial ring rolling mill after the outer die sleeve is assembled; in the high-pressure deformation process, the tooling and pre-rolled ring billet can be assembled and aligned on the anvil of the press, and then axial pressure can be applied by the press hammer to perform high-pressure deformation.

[0075] In a specific embodiment of the present invention, in the pre-rolling process, the outer die sleeve and the main roll and core roll dies in the horizontal radial-axial ring rolling mill are preheated to 200-470°C, and the maximum temperature of the dies does not exceed the heating temperature of the billet; in the high-pressure deformation, the press hammer, anvil, die core and lower pressure pad ring are preheated to 200-470°C, and the maximum temperature of the dies does not exceed the heating temperature of the billet.

[0076] In a specific embodiment of the present invention, the method further includes: performing solution treatment and aging heat treatment on the ring forging.

[0077] The operating conditions for solution treatment and aging heat treatment can be adjusted according to the conventional solution treatment and aging heat treatment conditions for aluminum alloys.

[0078] In a specific embodiment of the present invention, step (a) involves the preparation of the aluminum alloy ring billet, which includes: heating the aluminum alloy bar billet, upsetting and punching it, and then heating and rolling it.

[0079] In practice, the aluminum alloy ring blank used in this invention can be an aluminum alloy ring blank obtained by existing forming methods.

[0080] The aluminum alloy can be 7050 alloy, 2219 alloy, 5A06 alloy, 2A50 alloy, 2A70 alloy, 2A14 alloy, 7A04 alloy, 7A09 alloy, 7075 alloy, etc.

[0081] In a specific embodiment of the present invention, such as Figure 2 As shown, the rigid outer mold sleeve 2 is a ring structure with a rectangular cross-section. (The dimensions are...) Taking the aluminum alloy ring billet 1 as an example, the dimensions of the ring forging 6 obtained through pre-rolling and high-pressure deformation are also [missing information].

[0082] The inner diameter of the outer mold sleeve 2 is the same as the outer diameter D1 of the aluminum alloy ring blank 1, that is, the inner diameter of the outer mold sleeve 2 is D1. The height of the outer mold sleeve 2 is 1.2 to 1.55 times the height H1 of the aluminum alloy ring blank 1, that is, the height of the outer mold sleeve 2 is 1.2H1 to 1.55H1.

[0083] During the pre-rolling process, the outer die sleeve 2 is fitted over the aluminum alloy ring billet 1, such as... Figure 3 As shown. Preferably, after fitting, ensure the center of the outer die sleeve 2 aligns with the center of the aluminum alloy ring billet 1. Then, use a horizontal radial-axial ring rolling mill to roll the assembled outer die sleeve 2 and aluminum alloy ring billet 1 according to dimensions. Rolling is performed to obtain a size of The pre-rolled ring billet 3, such as Figure 4 As shown.

[0084] Figure 5 and Figure 6 These are schematic diagrams of the die core 4 and the lower pressure pad ring 5 used in the high-pressure deformation provided in this embodiment of the invention. The diameter of the die core 4 is the same as the inner diameter d1 of the aluminum alloy ring blank 1, that is, the diameter of the die core 4 is d1. The lower pressure pad ring 5 is a ring structure with a rectangular cross-section. The inner diameter of the lower pressure pad ring 5 is the same as the inner diameter d1 of the aluminum alloy ring blank 1, and the outer diameter is the same as the outer diameter D1 of the aluminum alloy ring blank 1. The height is the difference between the height H2 of the pre-rolled ring blank and the height H1 of the ring blank, that is, the inner diameter of the lower pressure pad ring 5 is d1, the outer diameter is D1, and the height is H2-H1.

[0085] Figure 7 This is a schematic diagram of the tooling and mold assembly during high-pressure deformation provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the assembly structure of the high-pressure deformation tooling and the pre-rolled ring billet. After the pre-rolled ring billet 3 is obtained through pre-rolling, an outer mold 2 is installed around the pre-rolled ring billet 3, as shown in the diagram. Figure 4 As shown. Figure 4 The structure is transferred to the anvil of the press. The die core 4 is placed and centered in the inner hole of the pre-rolled ring billet 3. Then, the lower pressure pad ring 5 is placed on the pre-rolled ring billet 3 and centered again. Figure 8 As shown. Then, an axial pressure is applied to the pre-rolled ring billet 3 using a press through the lower pressure pad ring 5 to perform high-pressure deformation, resulting in a size of... Ring forgings, such as Figure 9 As shown.

[0086] The present invention also provides an aluminum alloy ring forging obtained by any of the above-described methods for improving the tensile properties of aluminum alloy ring forgings.

[0087] The radial and high-axis tensile strength and yield strength of the aluminum alloy ring forging of the present invention are increased by 8% to 12% compared with the aluminum alloy ring blank, and the radial and high-axis plasticity (post-fracture elongation) are increased by 30% to 50% compared with the aluminum alloy ring blank.

[0088] For example, for 7050 alloy, the 7050 aluminum alloy ring forgings manufactured using the manufacturing method of the present invention have a tangential tensile strength ≥610MPa, a tangential yield strength ≥550MPa, and a tangential elongation ≥9%.

[0089] The radial tensile strength of the aluminum alloy ring forging is ≥599MPa, the radial yield strength is ≥520MPa, and the radial elongation is ≥7.7%.

[0090] The aluminum alloy ring forging has a high-direction tensile strength ≥580MPa, a high-direction yield strength ≥495MPa, and a high-direction elongation ≥6.2%.

[0091] Examples 1-2

[0092] This embodiment provides a manufacturing method for improving the tensile properties of 7050 aluminum alloy ring forgings, including the following steps:

[0093] (1) For 7050 aluminum alloy billets, according to Figure 10 The heating process involves heating the 7050 aluminum alloy billet according to the heating curve in the figure. Specifically, the 7050 aluminum alloy billet can be obtained by casting or extrusion, but is not limited to these methods. The heating process includes: using a furnace charging method at a low temperature or a furnace charging method at ≤300℃, the 7050 aluminum alloy billet is heated at 420~440℃ and held at (1.7~2.5) min / mm×the effective thickness of the billet (mm).

[0094] (2) Upsetting, drawing, and punching are performed on the billet obtained in step (1) to obtain an annular billet; specifically, upsetting and drawing includes: upsetting and drawing the billet along the axial direction by one or more downsetting or drawing operations, with the upsetting or drawing deformation controlled at 20% to 55%; during the upsetting or drawing process, each downsetting or drawing operation is 50 to 80 mm, paused for 4 to 8 seconds, and then the next downsetting or drawing operation is performed, so that the upsetting or drawing deformation reaches 25% to 55%; the punching includes: when punching, a large end diameter of The punch has a conical surface with an angle of 2° to 3°. First, the small end of the punch is pressed into the blank to a depth of 2 / 3 to 3 / 4 of the blank's height. The blank with the punch is then flipped over and placed on the punching die. The large end of a punch of the same size is aligned and pressed into the blank to remove the core material. The blank is then rounded, the bulge is adjusted, and large radius angles are eliminated to obtain a ring-shaped blank. During the forging process, the final forging temperature is ≥360℃.

[0095] (3) After heat treatment at 420-440℃, the annular billet obtained in step (2) is preformed to obtain an aluminum alloy annular billet; specifically: the preform includes: preforming the billet using a horizontal radial-axial ring rolling mill, the distance between the upper and lower tapered rolls is always kept constant at H1 during preforming, the deformation of the preform is 25%-60%, and the dimensions are determined according to the requirements. The process is controlled to obtain an aluminum alloy ring billet. During the forging process, the final forging temperature is ≥360℃.

[0096] (4) After the aluminum alloy ring blank obtained in step (3) is heated at 420-440℃, it is pre-rolled and subjected to high-pressure deformation to obtain a ring forging.

[0097] Specifically, pre-rolling treatment includes: designing and preparing an outer die sleeve with a fixed outer diameter required for the pre-rolling process, such as... Figure 2 As shown; preheat the main roller, core roller mold, and outer mold sleeve to 200–470°C, ensuring the mold temperature does not exceed the billet's heating temperature. Place the aluminum alloy ring billet in the outer mold sleeve, as shown. Figure 3 As shown; a horizontal radial-axial ring rolling mill was used to roll the dimensions. The pre-rolling process involves controlling the deformation to be between 25% and 55%. After pre-rolling, the overall height of the ring billet increases and becomes approximately flush with the height of the outer die sleeve, thus obtaining the pre-rolled ring billet. like Figure 4 As shown.

[0098] High-intensity compression deformation includes: designing and preparing the required mold core and compression pad ring as needed for high-intensity compression deformation, such as... Figure 5 and Figure 6 As shown; preheat the press hammer, anvil, die core, and lower pressure pad ring to 200-470℃, ensuring the die temperature does not exceed the billet's heating temperature. Transfer the pre-rolled ring billet (in its assembled state with the outer die set) to the press anvil. Place the die core into the inner hole of the pre-rolled ring billet and align it. Then, continue placing and aligning the lower pressure pad ring on the pre-rolled ring billet. Figure 8 As shown; then, a press is used to perform height reduction deformation on the pre-rolled ring billet; the deformation amount of height reduction deformation is controlled between 20% and 55%, and after the height reduction deformation is completed, the overall height and wall thickness of the ring billet are restored to the dimensions of the aluminum alloy ring billet.

[0099] Depending on the actual dimensions and performance requirements of the product, the number of pre-rolling treatments and height reduction deformations can be 1 or N times (N≥2). When it is N times, this step includes the first (pre-rolling treatment + height reduction deformation), the second (pre-rolling treatment + height reduction deformation), ... the Nth (pre-rolling treatment + height reduction deformation), after which a ring forging is obtained. Each pre-rolling treatment and height reduction deformation is performed in the same manner as described above.

[0100] (5) The ring forgings obtained in step (4) are processed according to... Figure 11 The heating curve in the process is subjected to a two-stage solution treatment. Specifically, the two-stage solution treatment includes: using a hot-loading furnace method, the ring forging is held at 465-470℃ for 4-6 hours, and then heated to 475-482℃ at a heating rate of 0.2-3℃ / min (e.g., 2℃ / min) and held for 6-10 hours before water cooling; the ring billet is transferred out of the furnace in ≤10s, the water temperature is controlled at 35-60℃, and the cooling time of the ring billet in water is 5-30min.

[0101] (6) The ring forgings obtained in step (5) are processed according to... Figure 12 The heating curve is subjected to artificial aging treatment (standard two-stage aging system).

[0102] Following the above steps and referring to the specific parameters in Table 1, ring forgings of different sizes were obtained.

[0103] Table 1 Specific parameters and conditions for different embodiments

[0104]

[0105]

[0106] Comparative Example 1

[0107] Comparative Example 1 refers to the manufacturing method of Example 1, except that step (4) is not included. The aluminum alloy ring blank obtained in step (3) is directly subjected to the two-stage solution heat treatment and artificial aging treatment in steps (5) and (6).

[0108] Experimental Example

[0109] To compare and illustrate the performance of 7050 aluminum alloy ring forgings obtained from different embodiments and comparative examples, the tensile properties of the 7050 aluminum alloy ring forgings obtained from different embodiments and comparative examples were tested. The test method referred to GB / T 16865, and the specific test results are shown in Table 2.

[0110] Table 2. Tensile property test results of different 7050 aluminum alloy ring forgings

[0111]

[0112] The manufacturing method of this invention improves the anisotropy of the mechanical properties of aluminum alloy ring forgings, including strength and plasticity, especially the anisotropy of plasticity. The radial and high-axis elongation test data of the comparative examples are significantly lower, while the radial and high-axis elongation, as well as tensile strength and yield strength of the aluminum alloy ring forgings obtained by the embodiments of this invention are significantly improved.

[0113] The test results above show that the aluminum alloy ring forgings obtained by the manufacturing method of the present invention have significantly improved the radial and vertical mechanical properties of the ring forgings while ensuring or even improving the tangential mechanical properties of the ring forgings, thus breaking through the bottleneck of the rolling technology of existing ring forgings.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manufacturing method for improving the tensile properties of aluminum alloy ring forgings, characterized in that, Includes the following steps: (a) The heat-treated aluminum alloy ring billet is pre-rolled to obtain a pre-rolled ring billet; in the pre-rolling process, the outer diameter of the aluminum alloy ring billet is kept constant, and radial pressure is applied along the inner wall of the aluminum alloy ring billet to increase the height of the aluminum alloy ring billet. (b) The pre-rolled ring blank is subjected to high-pressure deformation to obtain a ring forging; the high-pressure deformation keeps the outer diameter of the pre-rolled ring blank unchanged, and applies axial pressure to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank; In step (a), the method of keeping the outer diameter of the aluminum alloy ring blank unchanged includes: using an annular outer mold sleeve to fit over the aluminum alloy ring blank; the inner diameter of the annular outer mold sleeve is the same as the outer diameter of the aluminum alloy ring blank; In step (b), the method of keeping the outer diameter of the pre-rolled ring blank unchanged and applying axial pressure to the pre-rolled ring blank to reduce the inner diameter of the pre-rolled ring blank includes: fitting an annular outer mold sleeve around the pre-rolled ring blank, placing and centering a mold core inside the pre-rolled ring blank, placing and centering a lower pressure pad ring on the pre-rolled ring blank, and applying axial pressure to the lower pressure pad ring. The diameter or outer diameter of the mold core is the same as the inner diameter of the aluminum alloy ring blank; the height of the mold core is the same as the height of the aluminum alloy ring blank.

2. The manufacturing method according to claim 1, characterized in that, Also includes: Repeat steps (a) and (b).

3. The manufacturing method according to claim 2, characterized in that, Steps (a) and (b) are repeated 1 to 5 times.

4. The manufacturing method according to claim 2, characterized in that, In step (a), the temperature of the heat treatment is 420~470℃; the time of the heat treatment is 1.5~15h.

5. The manufacturing method according to claim 1, characterized in that, In step (a), the height of the pre-rolled ring billet is 1.2 to 1.55 times the height of the aluminum alloy ring billet.

6. The manufacturing method according to claim 1, characterized in that, In step (b), the deformation amount of the height compression deformation is 20% to 55%.

7. The manufacturing method according to claim 6, characterized in that, In step (b), the inner diameter of the ring forging after the height is reduced and deformed is the same as the inner diameter of the aluminum alloy ring blank; the height of the ring forging is the same as the height of the aluminum alloy ring blank.

8. The manufacturing method according to claim 1, characterized in that, The height of the annular outer mold sleeve is greater than or equal to the height of the pre-rolled annular billet after pre-rolling treatment.

9. The manufacturing method according to claim 1, characterized in that, The mold core is a cylindrical structure or a ring structure; The inner diameter of the lower pressure pad ring is the same as the inner diameter of the aluminum alloy ring blank, and the outer diameter of the lower pressure pad ring is the same as the outer diameter of the aluminum alloy ring blank; the height of the lower pressure pad ring is equal to the difference between the height of the pre-rolled ring blank and the height of the aluminum alloy ring blank.

10. The manufacturing method according to claim 1, characterized in that, Also includes: The ring forging is subjected to solution treatment and aging heat treatment.

11. The manufacturing method according to claim 1, characterized in that, In step (a), the preparation of the aluminum alloy ring billet includes: heating the aluminum alloy bar billet, upsetting and punching it, and then heating and rolling it.

12. An aluminum alloy ring forging obtained by the manufacturing method according to any one of claims 1 to 11.

13. The aluminum alloy ring forging according to claim 12, characterized in that, The aluminum alloy ring forging has a tangential tensile strength ≥610MPa, a tangential yield strength ≥550MPa, and a tangential elongation ≥9%.

14. The aluminum alloy ring forging according to claim 12, characterized in that, The radial tensile strength of the aluminum alloy ring forging is ≥599MPa, the radial yield strength is ≥520MPa, and the radial elongation is ≥7.7%.

15. The aluminum alloy ring forging according to claim 12, characterized in that, The aluminum alloy ring forging has a high-axis tensile strength ≥580MPa, a high-axis yield strength ≥495MPa, and a high-axis elongation ≥6.2%.

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