Machining method of 5-series aluminum alloy ring forge piece

Abstract

The invention relates to a machining method of a 5-series aluminum alloy ring forging, in particular to the field of aluminum alloy machining, and the machining method comprises the steps that first upsetting, first drawing-out, second upsetting, second drawing-out, third upsetting, third drawing-out, eight-direction punching, fourth upsetting, punching, ring rolling and heat treatment are sequentially conducted on a 5-series aluminum alloy casting blank, and a ring forging product is obtained; the absolute value of the difference value of the forging ratios of the first upsetting, the first drawing-out, the second upsetting, the second drawing-out, the third upsetting and the third drawing-out is smaller than or equal to 0.5. According to the machining method provided by the invention, the forging process is optimized, uniform strain capacity distribution is ensured, a fine and uniform structure can be obtained more easily, the phenomenon that recrystallization degrees in a material are different, and a crystal mixing phenomenon is generated is avoided, so that dislocation is rearranged through slip displacement and climbing, and a stable sub-crystal structure is formed; and the mechanical property of the obtained aluminum alloy is improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy processing, and specifically to a method for processing 5-series aluminum alloy ring forgings. Background Technology

[0002] Currently, the growing demand for high-performance, lightweight materials has driven the research and development of large, high-strength aluminum alloy ring forgings. These components are key parts of the main load-bearing structures such as rocket tanks, various protective rings, and connecting frames.

[0003] For example, CN120715160A discloses a method for preparing a large high-strength aluminum alloy ring. The aluminum alloy ring has a height of H and an outer diameter of D. The method for preparing the aluminum alloy ring includes the following steps: forging blanking: the aluminum alloy ingot is upset and drawn into a blank, and after the upset drawing is completed, a hole is punched to form a ring blank, and the height of the ring blank is controlled to be 1.2-1.3H; pre-ring rolling: the ring blank is pre-ring rolled so that the outer diameter of the pre-ring rolled ring blank is 0.5-0.6D; final ring rolling after one composite deformation and two composite deformations: the ring blank after the two composite deformations is rolled until the outer diameter is the same as that of the aluminum alloy ring product; hot deformation: the ring blank after the final ring rolling is heat-treated to obtain the aluminum alloy ring product.

[0004] Among them, 5-series aluminum alloys have become one of the key materials in these fields due to their excellent corrosion resistance, weldability and high strength. However, the current processing of 5-series aluminum alloy ring forgings has defects such as poor mechanical properties due to unreasonable forging, rolling and heat treatment processes. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a processing method for 5-series aluminum alloy ring forgings, so as to solve the defect of poor mechanical properties of ring forging products in the current processing of ring forgings.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a method for machining 5-series aluminum alloy ring forgings, the method comprising:

[0008] The 5-series aluminum alloy billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling, and heat treatment to obtain the ring forging product.

[0009] The absolute value of the difference between the forging ratios of the first roughing, the first drawing, the second roughing, the second drawing, the third roughing, and the third drawing is ≤0.5.

[0010] The processing method provided by this invention optimizes the forging process, ensuring uniform strain distribution, which is more conducive to obtaining a fine and uniform microstructure. It avoids uneven recrystallization and mixed crystal phenomena within the material, thereby allowing dislocations to rearrange through cross-slip displacement and climb to form a stable subcrystalline structure, thus improving the mechanical properties of the resulting aluminum alloy.

[0011] As a preferred technical solution of the present invention, the forging ratio of the first roughing is 1.6-1.8.

[0012] Preferably, the forging ratio of the first elongation is 2-2.2.

[0013] As a preferred technical solution of the present invention, the forging ratio of the second roughing is 2-2.2.

[0014] Preferably, the forging ratio of the second elongation is 2-2.2.

[0015] As a preferred embodiment of the present invention, the directions of the first elongation and the second elongation are different.

[0016] As a preferred embodiment of the present invention, the forging ratio of the third roughing is 1.8-2.

[0017] The forging ratio of the third drawing is 1.5-1.7.

[0018] As a preferred embodiment of the present invention, the second elongation and the third elongation are in different directions.

[0019] As a preferred technical solution of the present invention, the forging ratio of the fourth roughing is 3.2-3.5.

[0020] As a preferred embodiment of the present invention, the temperature of the rolling ring is 340-400℃.

[0021] As a preferred embodiment of the present invention, the heat treatment includes: heat preservation followed by air cooling.

[0022] As a preferred embodiment of the present invention, the insulation temperature is 290-350℃.

[0023] Preferably, the heat preservation time is 10-10.5 hours.

[0024] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0025] (1) The processing method provided by the present invention fundamentally regulates the recovery and recrystallization process of the material by controlling the reasonable amount of deformation, which makes the forging structure highly uniform and refined, eliminates mixed crystals to a large extent, ensures the consistency of the structure between different parts of the product and between different batches, and greatly improves the stability of mechanical properties, thereby achieving further lightweighting of the structure under the premise of ensuring absolute safety.

[0026] (2) The processing method provided by this invention, which involves rolling (ring rolling) in the medium temperature range of 340℃-400℃, cleverly utilizes the deformation physical mechanism of this aluminum alloy in a specific temperature range, maximizing the dislocation strengthening effect and finding the optimal balance between material strength and plasticity. This avoids the deformation difficulties at low temperatures and inhibits dynamic recrystallization and grain growth at high temperatures, introducing a high-density, stable dislocation structure into the material, providing significant dislocation strengthening. This greatly improves the service safety and reliability of the equipment.

[0027] (3) The processing method provided by the present invention, by adopting a heat treatment process of 290℃-350℃, can effectively eliminate macroscopic residual stress while retaining enough dislocation structures to maintain the strength level of the material, thus significantly improving the pass rate of processing and reducing losses caused by repeated corrections and scrap. Smaller processing deformation means that a smaller processing allowance can be left in the initial design, which not only saves valuable raw materials and reduces the time and cost of cutting processing, but also promotes the optimization of the entire manufacturing chain.

[0028] (4) The processing method provided by the present invention can significantly improve the mechanical properties of 5 series aluminum alloys through the optimization of the processing process. The compressive strength is ≥196MPa, the yield strength is ≥95MPa, and the elongation is ≥19%. Under the preferred scheme, the compressive strength is ≥219MPa, the yield strength is ≥100MPa, and the elongation is ≥28%.

[0029] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0030] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0031] Currently, in the preparation of 5-series aluminum alloy ring forgings, unreasonable process design leads to uneven recrystallization within the material, resulting in mixed crystal phenomena that severely affect the mechanical properties and stability of the product. Based on this, this invention significantly optimizes the grain distribution of the forging product by optimizing the processing, specifically the forging and rolling processes. The forging process of this invention enables dislocations to rearrange through cross-slip displacement and climb, forming a stable subcrystalline structure, providing a consistent initial microstructure for subsequent passes. The design of the rolling process allows for the formation of high-density dislocation entanglements and cellular structures within the material, becoming preferred nucleation sites for precipitated phases during subsequent heat treatment. This results in aluminum alloy ring forgings possessing excellent mechanical properties, as detailed below:

[0032] I. This embodiment provides a method for machining 5-series aluminum alloy ring forgings, the machining method including:

[0033] The 5-series aluminum alloy billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling, and heat treatment to obtain the ring forging product.

[0034] In this invention, 5-series aluminum alloys refer to aluminum alloy series with magnesium as the main alloying element, such as aluminum alloy 5A03, aluminum alloy 5A05, aluminum alloy 5A06, aluminum alloy 5083, etc.

[0035] In this invention, "octagonal" refers to processing a quadrangular prism forging blank into an octagonal prism of approximately equal length, with the length varying from 20 to 50 mm.

[0036] Specifically, the absolute value of the difference between the forging ratios of the first forging, the first drawing, the second forging, the second drawing, the third forging, and the third drawing is ≤0.5.

[0037] The forging ratio of the first roughing pass is 1.6-1.8, for example, it can be 1.6, 1.62, 1.64, 1.66, 1.68, 1.7, 1.72, 1.74, 1.76, 1.78 or 1.8, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0038] The forging ratio of the first drawing is 2-2.2, for example, it can be 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.12, 2.14, 2.16, 2.18 or 2.2, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0039] The forging ratio of the second roughing is 2-2.2, for example, it can be 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.12, 2.14, 2.16, 2.18 or 2.2, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0040] The forging ratio of the second drawing is 2-2.2, for example, it can be 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.12, 2.14, 2.16, 2.18 or 2.2, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0041] The first and second elongations are in different directions.

[0042] The forging ratio of the third roughing is 1.8-2, for example, it can be 1.8, 1.82, 1.84, 1.86, 1.88, 1.9, 1.92, 1.94, 1.96, 1.98 or 2, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0043] The forging ratio of the third drawing is 1.5-1.7, for example, it can be 1.5, 1.52, 1.54, 1.56, 1.58, 1.6, 1.62, 1.64, 1.66, 1.68 or 1.7, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0044] The second and third elongations are in different directions.

[0045] In this invention, the directions of the first elongation, the second elongation, and the third elongation can be selected and designed according to conventional requirements in the art, but must meet the limitations of this invention.

[0046] The forging ratio of the fourth roughing pass is 3.2-3.5, for example, it can be 3.2, 3.23, 3.26, 3.29, 3.32, 3.35, 3.38, 3.41, 3.44, 3.47 or 3.5, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0047] The temperature of the rolling ring is 340-400℃, for example, it can be 340℃, 346℃, 352℃, 358℃, 364℃, 370℃, 376℃, 382℃, 388℃, 394℃ or 400℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0048] The heat treatment includes: heat preservation followed by air cooling.

[0049] The insulation temperature is 290-350℃, for example, it can be 290℃, 296℃, 302℃, 308℃, 314℃, 320℃, 326℃, 332℃, 338℃, 344℃ or 350℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0050] The heat preservation time is 10-10.5 hours, for example, it can be 10 hours, 10.05 hours, 10.1 hours, 10.15 hours, 10.2 hours, 10.25 hours, 10.3 hours, 10.35 hours, 10.4 hours, 10.45 hours or 10.5 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0051] In this invention, the endpoint of air cooling is reaching room temperature, such as 15-35°C.

[0052] In this invention, subsequent machining processes can be performed after air cooling.

[0053] II. To illustrate the effects of the ring forging obtained by the processing method of the 5-series aluminum alloy ring forging provided by the present invention, the following practical example is used for explanation:

[0054] Example 1

[0055] This embodiment provides a method for machining 5-series aluminum alloy ring forgings, the method comprising:

[0056] The 5-series aluminum alloy (5A03) billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling and heat treatment to obtain the ring forging product.

[0057] Wherein, the absolute value of the difference between the forging ratios of the first roughing, the first drawing, the second roughing, the second drawing, the third roughing, and the third drawing is ≤0.5; the forging ratio of the first roughing is 1.7; the forging ratio of the first drawing is 2.1; the forging ratio of the second roughing is 2.1; the forging ratio of the second drawing is 2.1; the directions of the first and second drawings are different; the forging ratio of the third roughing is 1.9; the forging ratio of the third drawing is 1.6; the directions of the second and third drawings are different; and the forging ratio of the fourth roughing is 3.3.

[0058] The temperature of the rolling ring is 360°C;

[0059] The heat treatment includes: holding at 300°C for 10.4 hours and then air cooling to room temperature of 25°C.

[0060] Example 2

[0061] This embodiment provides a method for machining 5-series aluminum alloy ring forgings, the method comprising:

[0062] The 5-series aluminum alloy (5A05) billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling and heat treatment to obtain the ring forging product.

[0063] Wherein, the absolute value of the difference between the forging ratios of the first forging, the first drawing, the second forging, the second drawing, the third forging, and the third drawing is ≤0.5; the forging ratio of the first forging is 1.75; the forging ratio of the first drawing is 2.05; the forging ratio of the second forging is 2.05; the forging ratio of the second drawing is 2.05; the directions of the first drawing and the second drawing are different; the forging ratio of the third forging is 1.85; the forging ratio of the third drawing is 1.65; the directions of the second drawing and the third drawing are different; and the forging ratio of the fourth forging is 3.4.

[0064] The temperature of the rolling ring is 380℃;

[0065] The heat treatment includes: holding at 320°C for 10.3 hours and then air cooling to room temperature of 25°C.

[0066] Example 3

[0067] This embodiment provides a method for machining 5-series aluminum alloy ring forgings, the method comprising:

[0068] The 5-series aluminum alloy (5A06) billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling and heat treatment to obtain the ring forging product.

[0069] Wherein, the absolute value of the difference between the forging ratios of the first forging, the first drawing, the second forging, the second drawing, the third forging, and the third drawing is ≤0.5; the forging ratio of the first forging is 1.6; the forging ratio of the first drawing is 2; the forging ratio of the second forging is 2; the forging ratio of the second drawing is 2; the directions of the first drawing and the second drawing are different; the forging ratio of the third forging is 1.8; the forging ratio of the third drawing is 1.5; the directions of the second drawing and the third drawing are different; the forging ratio of the fourth forging is 3.2.

[0070] The temperature of the rolling ring is 340℃;

[0071] The heat treatment includes: holding at 290°C for 10.5 hours and then air cooling to room temperature of 25°C.

[0072] Example 4

[0073] This embodiment provides a method for machining 5-series aluminum alloy ring forgings, the method comprising:

[0074] The 5-series aluminum alloy (5083) billet was subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling and heat treatment to obtain the ring forging product.

[0075] Wherein, the absolute value of the difference between the forging ratios of the first forging, the first drawing, the second forging, the second drawing, the third forging, and the third drawing is ≤0.5; the forging ratio of the first forging is 1.8; the forging ratio of the first drawing is 2.2; the forging ratio of the second forging is 2.2; the forging ratio of the second drawing is 2.2; the directions of the first drawing and the second drawing are different; the forging ratio of the third forging is 2; the forging ratio of the third drawing is 1.7; the directions of the second drawing and the third drawing are different; and the forging ratio of the fourth forging is 3.5.

[0076] The temperature of the rolling ring is 400℃;

[0077] The heat treatment includes: holding at 350°C for 10 hours and then air cooling to room temperature of 25°C.

[0078] Example 5

[0079] The only difference from Example 1 is that the rolling temperature is 300°C.

[0080] Example 6

[0081] The only difference from Example 1 is that the rolling temperature is 450°C.

[0082] Example 7

[0083] The only difference from Example 1 is that the holding temperature during heat treatment is 250°C.

[0084] Example 8

[0085] The only difference from Example 1 is that the holding temperature during heat treatment is 400°C.

[0086] Comparative Example 1

[0087] The only difference from Example 1 is that the first roughing is not performed.

[0088] Comparative Example 2

[0089] The only difference from Example 1 is that the first stretching is not performed.

[0090] Comparative Example 3

[0091] The only difference from Example 1 is that a second roughing is not performed.

[0092] Comparative Example 4

[0093] The only difference from Example 1 is that a second stretching is not performed.

[0094] Comparative Example 5

[0095] The only difference from Example 1 is that a third roughing is not performed.

[0096] Comparative Example 6

[0097] The only difference from Example 1 is that a third stretching is not performed.

[0098] Comparative Example 7

[0099] The only difference from Example 1 is that no heat treatment is performed.

[0100] Comparative Example 8

[0101] The only difference from Example 1 is that the forging ratio of the first roughing is 1.5.

[0102] Comparative Example 9

[0103] The only difference from Example 1 is that the forging ratio of the first roughing is 2.8.

[0104] Comparative Example 10

[0105] The only difference from Example 1 is that the forging ratio of the first drawing is 1.5.

[0106] Comparative Example 11

[0107] The only difference from Example 1 is that the forging ratio of the first drawing is 2.8.

[0108] Comparative Example 12

[0109] The only difference from Example 1 is that the forging ratio of the second roughing is 1.5.

[0110] Comparative Example 13

[0111] The only difference from Example 1 is that the forging ratio of the second roughing is 2.8.

[0112] Comparative Example 14

[0113] The only difference from Example 1 is that the forging ratio of the second drawing is 1.5.

[0114] Comparative Example 15

[0115] The only difference from Example 1 is that the forging ratio of the second drawing is 2.8.

[0116] Comparative Example 16

[0117] The only difference from Example 1 is that the forging ratio of the third roughing is 1.5.

[0118] Comparative Example 17

[0119] The only difference from Example 1 is that the forging ratio of the third roughing is 2.8.

[0120] Comparative Example 18

[0121] The only difference from Example 1 is that the forging ratio of the third drawing is 1.5.

[0122] Comparative Example 19

[0123] The only difference from Example 1 is that the forging ratio of the third drawing is 2.8.

[0124] The mechanical properties of the ring forgings obtained in the above embodiments and comparative examples were tested according to ISO 6892-1:2019, and the results are shown in Table 1 below.

[0125] Table 1

[0126]

[0127] As shown in Table 1, the solution provided by this invention optimizes the forging process, ensuring sufficient deformation to provide adequate driving force for dynamic recrystallization, thus ensuring sufficiently refined and uniformly distributed grains. Simultaneously, it breaks up coarse second phases and defects such as porosity and pores in the as-cast microstructure, achieving microstructural densification and significantly improving strength and toughness. Insufficient deformation leads to incomplete dynamic recrystallization, leaving a large number of coarse as-cast grains and deformation bands in the microstructure, resulting in significant dispersion in mechanical properties. Excessive deformation causes excessive internal stress accumulation in the metal, easily generating residual cracks, and may lead to abnormal grain orientation (texture segregation) due to uneven local deformation, reducing fatigue resistance. Insufficient deformation fails to eliminate as-cast defects, resulting in a loose microstructure and coarse grains, failing to meet strength and plasticity requirements. Excessive deformation causes stress concentration exceeding the material's fracture strength, leading to obvious macroscopic defects such as cracks and distortion in the forging, resulting in direct scrapping. By employing a reasonable rolling temperature, dislocation slip resistance is minimized. Combined with low feed rate control, uniform plastic deformation of thick-walled billets can be achieved, avoiding linear cracks or dense point defects caused by uneven stress. However, if an unreasonable temperature is used, the alloy elongation decreases at low temperatures, and the plastic reserve is insufficient. During the rolling process, the metal flow of thick-walled billets is hindered, easily forming shear cracks in the middle of the wall thickness. Flaw detection can reveal linear defects around the entire ring. At the same time, low-temperature deformation requires increased rolling force, which may lead to grooves or local depressions on the end face of the ring, resulting in unqualified surface quality. Because the temperature is below the recrystallization completion temperature, dynamic recrystallization only occurs in local high-deformation areas, leaving a large number of fibrous deformation bands and unrecrystallized coarse grains in the microstructure. If a higher temperature is used, the grain boundary migration resistance drops sharply at high temperatures, and the grain size can grow rapidly. The tensile strength drops below 180 MPa, and the impact toughness decreases by more than 30%. For components that need to withstand cyclic loads, the coarse-grained microstructure easily induces fatigue crack initiation at the grain boundaries, significantly shortening the service life.

[0128] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0129] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0130] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for machining 5-series aluminum alloy ring forgings, characterized in that, The processing method includes: The 5-series aluminum alloy billet is subjected to the following processes in sequence: first upsetting, first drawing, second upsetting, second drawing, third upsetting, third drawing, octagonal forming, fourth upsetting, punching, ring rolling, and heat treatment to obtain the ring forging product. The absolute value of the difference between the forging ratios of the first roughing, the first drawing, the second roughing, the second drawing, the third roughing, and the third drawing is ≤0.

5.

2. The processing method as described in claim 1, characterized in that, The forging ratio of the first roughing pass is 1.6-1.8; Preferably, the forging ratio of the first elongation is 2-2.

2.

3. The processing method as described in claim 1, characterized in that, The forging ratio of the second roughing pass is 2-2.2; Preferably, the forging ratio of the second elongation is 2-2.

2.

4. The processing method as described in claim 1, characterized in that, The first and second pulls are in different directions.

5. The processing method as described in claim 1, characterized in that, The forging ratio of the third roughing pass is 1.8-2; Preferably, the forging ratio of the third drawing is 1.5-1.

7.

6. The processing method as described in claim 1, characterized in that, The second and third elongations are in different directions.

7. The processing method as described in claim 1, characterized in that, The forging ratio of the fourth roughing pass is 3.2-3.

5.

8. The processing method as described in claim 1, characterized in that, The temperature of the rolling ring is 340-400℃.

9. The processing method as described in claim 1, characterized in that, The heat treatment includes: holding the temperature and then air cooling.

10. The processing method as described in claim 9, characterized in that, The insulation temperature is 290-350℃; Preferably, the heat preservation time is 10-10.5 hours.

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