Method for rapidly reducing quenching residual stress of aluminum alloy plate

Abstract

The invention belongs to the field of aluminum alloy processing, and relates to a method for rapidly reducing quenching residual stress of an aluminum alloy plate, which comprises the following steps: S1, carrying out solid solution quenching treatment on the aluminum alloy plate; s2, the aluminum alloy plate is subjected to primary flattening treatment; and S3, the aluminum alloy plate subjected to primary flattening treatment is subjected to primary cold pressing machining. And S4, the first-pass cold pressing plate is rotated by 85-95 degrees, second-pass cold pressing machining is conducted, and the multi-direction cold pressing plate is obtained. The total deformation amount of the cold pressing processing is 4-5%. And S5, secondary flattening treatment is conducted, and a flattened plate is obtained. And S6, the flat plate is subjected to stepped aging treatment, and the stress-eliminated aluminum alloy plate is obtained. The method for eliminating the quenching residual stress of the aluminum alloy plate is efficient, high in precision and low in cost, solves the problem of low production efficiency of a pre-stretching method in the prior art, and has a wide industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy processing technology, and specifically relates to a method for rapidly reducing residual stress in aluminum alloy plates after quenching. Background Technology

[0002] Aluminum alloys, particularly the 6xxx series (Al-Mg-Si series), are widely used in construction, transportation, industrial profiles, and automotive industries due to their excellent comprehensive properties, such as moderate strength, good formability, weldability, and corrosion resistance. During manufacturing, aluminum alloy sheets typically undergo solution treatment followed by rapid quenching to obtain a supersaturated solid solution.

[0003] However, due to the significant difference in cooling rates between the surface and core of the aluminum alloy sheet during quenching, uneven thermal shrinkage occurs, resulting in a complex three-dimensional residual stress field within the material. This residual stress not only manifests as macroscopic sheet warping, but more seriously, during subsequent machining, localized stress release can cause uncontrollable deformation of the workpiece, either as a whole or in specific areas. This severely affects machining accuracy, assembly efficiency, and product qualification rate, and may even lead to the scrapping of parts.

[0004] To address the aforementioned problems, existing technologies generally employ a pre-stretching method to eliminate residual stress within aluminum alloy quenched plates. This method applies a certain tensile force to the aluminum alloy quenched plate, increasing the overall yield strength of the material and enhancing its resistance to external forces, thereby improving the material's resistance to processing deformation. This method can eliminate over 90% of the residual internal stress within the aluminum alloy quenched plate; however, its production efficiency is extremely low, making it unsuitable for large-scale mass production.

[0005] Therefore, there is a need for a method that can effectively eliminate residual stress inside aluminum alloy quenched plates and improve production efficiency. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the problem of low production efficiency in the pre-stretching method for eliminating residual stress inside aluminum alloy quenched plates in existing technologies, this invention provides a method for rapidly reducing residual stress in quenched aluminum alloy plates.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0010] A method for rapidly reducing residual stress in quenched aluminum alloy plates includes the following steps:

[0011] S1: Perform solution hardening treatment on the aluminum alloy sheet to be treated to obtain the quenched aluminum alloy sheet:

[0012] S2: Initial leveling treatment of quenched aluminum alloy sheet;

[0013] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process to obtain the first cold-pressed sheet.

[0014] S4: The first-pass cold-pressed sheet is rotated 85-95° around the rotating axis, and then subjected to a second cold-pressing process to obtain a multi-directional cold-pressed sheet; wherein, the rotating axis is perpendicular to the surface of the first-pass cold-pressed sheet; the total cold-pressing deformation of the first and second cold-pressing processes is 4-5% of the initial thickness of the aluminum alloy sheet;

[0015] S5: Perform a secondary leveling process on the multi-directional cold-pressed sheet to obtain a flat sheet;

[0016] S6: Perform stepped aging treatment on flat sheet metal to obtain stress-relieved aluminum alloy sheet metal.

[0017] The method for rapidly reducing residual stress in aluminum alloy plates as described above is preferably performed in step S1 by solution treatment of the aluminum alloy plate to be treated at 460-520°C for 1-4 hours, followed by quenching treatment using water or a polymer aqueous solution as the quenching medium.

[0018] In the method described above for rapidly reducing residual stress during quenching of aluminum alloy plates, preferably, in step S1, the quenching transfer time is ≤15s.

[0019] In the method described above for rapidly reducing residual stress in aluminum alloy plates after quenching, preferably, in step S2, a multi-roll straightener is used for initial leveling, with a reduction of 0.5-1%.

[0020] In the method described above for rapidly reducing residual stress in aluminum alloy plates after quenching, preferably, in step S3, the cold pressing deformation amount of the first cold pressing process is 50-60% of the total cold pressing deformation amount.

[0021] In the method described above for rapidly reducing residual stress in aluminum alloy plates after quenching, preferably, in step S4, the cold pressing deformation amount of the second cold pressing process is 40-50% of the total cold pressing deformation amount.

[0022] In the method for rapidly reducing residual stress in aluminum alloy plates as described above, preferably, in step S5, the reduction amount of the secondary leveling treatment is 0.1-0.3%.

[0023] In the method for rapidly reducing residual stress in aluminum alloy plates as described above, preferably, in step S6, the stepped aging treatment includes a first-level aging treatment and a second-level aging treatment in sequence.

[0024] In the method for rapidly reducing residual stress in aluminum alloy plates as described above, preferably, in step S6, the temperature of the first-stage aging treatment is 105-120℃ and the time is 4-8h; the temperature of the second-stage aging treatment is 155-170℃ and the time is 8-16h.

[0025] (III) Beneficial Effects

[0026] The beneficial effects of this invention are:

[0027] This invention employs a two-stage cold pressing process, controlling the total cold pressing deformation to 4-5% of the initial thickness of the aluminum alloy sheet, effectively eliminating 80-90% of the residual quenching stress within the sheet. This method avoids the large equipment and lengthy clamping and stretching process required by the pre-stretching method. The entire process can be completed quickly on a continuous production line, significantly increasing production efficiency by over 80% compared to the pre-stretching method. It perfectly balances stress relief and production efficiency, making it suitable for modern large-scale mass production.

[0028] The two cold pressing processes and appropriate deformation amounts of this invention can optimize the internal crystal structure of aluminum alloys, increasing their yield strength by about 10% and ensuring that the material is more resistant to deformation in subsequent processing.

[0029] This invention also combines multiple cold pressing processes with stepped aging treatments, which can further stabilize the microstructure of aluminum alloy sheets, resulting in comprehensive optimization of the final product in terms of strength, toughness, and dimensional stability, and providing high-performance blanks for subsequent processing. Specific Implementation

[0030] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0031] This invention provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, comprising the following steps:

[0032] S1: Perform solution hardening treatment on the aluminum alloy sheet to be treated to obtain a quenched aluminum alloy sheet.

[0033] S2: Perform initial leveling treatment on quenched aluminum alloy sheets.

[0034] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process to obtain the first cold-pressed sheet.

[0035] S4: The first-pass cold-pressed sheet is rotated 85-95° around the rotating axis, and then a second cold-pressing process is performed to obtain a multi-directional cold-pressed sheet; wherein, the rotating axis is perpendicular to the surface of the first-pass cold-pressed sheet; the total cold-pressing deformation of the first and second cold-pressing processes is 4-5% of the initial thickness of the aluminum alloy sheet.

[0036] S5: Perform a secondary leveling process on the multi-directional cold-pressed sheet to obtain a flat sheet.

[0037] S6: Perform stepped aging treatment on flat sheet metal to obtain stress-relieved aluminum alloy sheet metal.

[0038] This invention employs a two-stage cold pressing process, controlling the total cold pressing deformation to 4-5% of the initial thickness of the aluminum alloy sheet. This effectively eliminates 80-90% of the residual quenching stress within the sheet, far exceeding the 50-70% effect of ordinary single-pass cold pressing. This method avoids the large equipment and lengthy clamping and stretching process required by the pre-stretching method. The entire process can be completed quickly on a continuous production line, significantly increasing production efficiency by over 80% compared to the pre-stretching method. It perfectly balances stress relief and production efficiency, making it suitable for modern large-scale mass production.

[0039] The two cold pressing processes and appropriate deformation amounts of this invention optimize the internal crystal structure of the aluminum alloy, increasing its yield strength by approximately 10% and ensuring that the material is more resistant to deformation during subsequent processing. Furthermore, this invention combines multiple cold pressing processes with stepped aging treatment, which further stabilizes the microstructure of the aluminum alloy sheet, resulting in a comprehensive optimization of the final product in terms of strength, toughness, and dimensional stability, providing high-performance blanks for subsequent processing.

[0040] Preferably, in step S1 above, the aluminum alloy sheet to be treated is solution treated at 460-520℃ for 1-4 hours. Solution treatment allows the strengthening phase to fully dissolve into the aluminum matrix, forming a supersaturated solid solution. After solution treatment, a rapid quenching process is performed using water or a polymer aqueous solution as the quenching medium. The quenching transfer time is ≤15 seconds to ensure the supersaturated solid solution is fixed, obtaining a high concentration of vacancies and distortion energy, preparing for subsequent aging. The quenching transfer time typically refers to the time interval between the workpiece being removed from the heating furnace and being fully immersed in the quenching medium to begin cooling; in this invention, it specifically refers to the time interval between the aluminum alloy sheet being transferred from the high-temperature environment to the quenching medium after solution treatment. In addition, the aluminum alloy sheet to be processed in step S1 refers to the aluminum alloy semi-finished sheet that has been cast, homogenized, hot rolled or hot extruded and cooled to room temperature. It usually exists in the form of hot rolled slab or hot rolled coil. The sheet has not undergone solution treatment before entering the process of this invention. Its structure is mainly composed of recrystallized grains and dispersed undissolved strengthening phases, and it is in an initial state that can be heat treated.

[0041] Preferably, in step S2 above, a multi-roll straightener is used for initial leveling, with a reduction of 0.5-1%, to avoid introducing excessive additional stress. The purpose of the initial leveling is to quickly correct the macroscopic warping caused by quenching, obtain aluminum alloy sheets with good initial flatness, and provide a good sheet shape foundation for subsequent high-precision cold pressing.

[0042] Preferably, in step S3 above, the cold pressing deformation amount of the first cold pressing process is 50-60% of the total cold pressing deformation amount, and in step S4, the cold pressing deformation amount of the second cold pressing process is 40-50% of the total cold pressing deformation amount. The first-pass cold-pressed sheet is rotated 85-95° around the rotation axis, that is, rotated without changing the plane on which the upper and lower surfaces of the sheet lie. The temperature of the two cold pressing processes is 20-30℃, and the processing time is 20-40s.

[0043] In this invention, the two cold pressing processes are the core steps for eliminating residual stress, and can be performed using a precision cold rolling mill capable of cross rolling or a dedicated calender. Unidirectional cold pressing only "irons" the stress in one direction, which may lead to stress direction transfer rather than complete elimination. The multidirectional cold pressing of this invention can coordinate and adjust the crystal lattice from two nearly perpendicular directions, which can more effectively disrupt and reorganize the distorted crystal structure introduced by quenching, promote the rearrangement and annihilation of dislocations, and thus more uniformly and thoroughly reduce multidirectional residual stress, avoiding the anisotropy problems caused by unidirectional processing. At the same time, multi-pass cold pressing is beneficial for controlling the rolling force and precisely controlling the sheet shape.

[0044] The residual stress inside the aluminum alloy quenched plate is three-dimensional, non-uniform, and anisotropic, mainly caused by the difference in cooling rates between the surface and the core. This manifests as tension on the surface and compression on the core, with asymmetrical stress distribution along the original rolling direction and transversely, and complex shear stress components. If only unidirectional cold pressing in step S3 is performed, it can only effectively release the stress in one main direction, while the stress in other directions may be locked or even aggravated, resulting in incomplete stress release and significant anisotropy.

[0045] The first cold pressing mainly releases the residual stress along the original rolling direction, while the second cold pressing after rotation focuses on releasing the residual stress in the transverse direction. The superposition of the two approximately perpendicular compression deformations makes the original stress distribution tend to be isotropic, avoiding the stress shift problem caused by deformation in a single direction.

[0046] After cold pressing, the sheet may have minor shape defects. Therefore, in step S5, a high-precision straightening machine can be used to perform micro-straightening. Preferably, in step S5, the reduction amount of the secondary flattening process is 0.1-0.3%.

[0047] The sheet material after cold pressing is in a work-hardened state and needs to be aged to restore its toughness and obtain its final strength. This invention uses a stepped aging treatment to achieve this. Specifically, in step S6, the stepped aging treatment includes a first-stage aging treatment and a second-stage aging treatment. The temperature of the first-stage aging treatment is 105-120℃, and the time is 4-8 hours; the temperature of the second-stage aging treatment is 155-170℃, and the time is 8-16 hours.

[0048] The first-stage aging treatment primarily forms numerous small, uniformly distributed GP regions. These solute atom clusters effectively pin dislocations, providing nucleation sites for subsequent precipitation. The second-stage aging treatment, based on the existing GP regions, promotes the uniform and dense precipitation of the metastable η' phase. Compared to traditional single-stage peak aging, this stepped aging treatment, through synergy with the high-density dislocations and vacancy defects introduced by cold pressing, results in more uniform and finer precipitation of the strengthening phase. This not only ensures the final mechanical properties of the material, but the uniform precipitation also helps to further relax the third type of residual stress at the microscopic level, stabilizing and maximizing the stress relief effect, and preventing stress recovery during long-term service or processing.

[0049] To further clarify the present invention and its technological advancements, the following description is provided in conjunction with specific embodiments and technical effects.

[0050] Example 1

[0051] This embodiment provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, including the following steps:

[0052] S1: The aluminum alloy sheet to be treated is solution treated at 500℃ for 3 hours. After the solution treatment, it is quickly quenched to obtain a quenched aluminum alloy sheet. The quenching medium in this step is water, and the quenching transfer time is 10 seconds.

[0053] S2: A multi-roller straightener is used to perform initial leveling of the quenched aluminum alloy sheet, with a reduction of 0.7%.

[0054] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process. The cold pressing deformation is 55% of the total cold pressing deformation, and the first cold-pressed sheet is obtained.

[0055] S4: The first-pass cold-pressed sheet is rotated 90° around the rotation axis, and then subjected to a second cold-pressing process. The cold-pressing deformation is 45% of the total cold-pressing deformation, resulting in a multi-directional cold-pressed sheet. Specifically, the rotation axis is perpendicular to the surface of the first-pass cold-pressed sheet. In steps S3 and S4, the total cold-pressing deformation of the first and second cold-pressing processes is 4.5% of the initial thickness of the aluminum alloy sheet. The temperature for both cold-pressing processes is 25°C, and the processing time is 30 seconds for both.

[0056] S5: A high-precision straightening machine is used to perform secondary leveling on the multi-directional cold-pressed sheet material, with a reduction of 0.2%, to obtain a flat sheet material.

[0057] S6: The flat sheet material is subjected to a first-stage aging treatment and a second-stage aging treatment in sequence to obtain a stress-relieved aluminum alloy sheet material. The first-stage aging treatment is carried out at a temperature of 110℃ for 6 hours, and the second-stage aging treatment is carried out at a temperature of 163℃ for 13 hours.

[0058] Example 2

[0059] This embodiment provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, including the following steps:

[0060] S1: The aluminum alloy sheet to be treated is solution treated at 460℃ for 4 hours. After the solution treatment, it is quickly quenched to obtain a quenched aluminum alloy sheet. The quenching medium in this step is water, and the quenching transfer time is 13 seconds.

[0061] S2: A multi-roller straightener is used to perform initial leveling of the quenched aluminum alloy sheet, with a reduction of 0.5%.

[0062] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process. The cold pressing deformation is 50% of the total cold pressing deformation, and the first cold-pressed sheet is obtained.

[0063] S4: The first-pass cold-pressed sheet is rotated 85° around the rotation axis, and then subjected to a second cold-pressing process. The cold-pressing deformation is 50% of the total cold-pressing deformation, resulting in a multi-directional cold-pressed sheet. Specifically, the rotation axis is perpendicular to the surface of the first-pass cold-pressed sheet. In steps S3 and S4, the total cold-pressing deformation of the first and second cold-pressing processes is 4% of the initial thickness of the aluminum alloy sheet. The temperature for both cold-pressing processes is 20°C, and the processing time is 40 seconds for both.

[0064] S5: A high-precision straightening machine is used to perform secondary leveling on the multi-directional cold-pressed sheet material, with a reduction of 0.1%, to obtain a flat sheet material.

[0065] S6: The flat sheet material is subjected to a first-stage aging treatment and a second-stage aging treatment in sequence to obtain a stress-relieved aluminum alloy sheet material. The first-stage aging treatment is carried out at a temperature of 105℃ for 8 hours, and the second-stage aging treatment is carried out at a temperature of 155℃ for 16 hours.

[0066] Example 3

[0067] This embodiment provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, including the following steps:

[0068] S1: The aluminum alloy sheet to be treated is solution treated at 520℃ for 1 hour. After the solution treatment, it is quickly quenched to obtain a quenched aluminum alloy sheet. The quenching medium in this step is water, and the quenching transfer time is 12 seconds.

[0069] S2: A multi-roller straightener is used to perform initial leveling of the quenched aluminum alloy sheet, with a reduction of 1%.

[0070] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process. The cold pressing deformation is 60% of the total cold pressing deformation, and the first cold-pressed sheet is obtained.

[0071] S4: The first-pass cold-pressed sheet is rotated 95° around the rotation axis, and then subjected to a second cold-pressing process. The cold-pressing deformation is 40% of the total cold-pressing deformation, resulting in a multi-directional cold-pressed sheet. Specifically, the rotation axis is perpendicular to the surface of the first-pass cold-pressed sheet. In steps S3 and S4, the total cold-pressing deformation of the first and second cold-pressing processes is 5% of the initial thickness of the aluminum alloy sheet. The temperature for both cold-pressing processes is 30°C, and the processing time is 20 seconds for each.

[0072] S5: A high-precision straightening machine is used to perform secondary leveling on the multi-directional cold-pressed sheet material, with a reduction of 0.3%, to obtain a flat sheet material.

[0073] S6: The flat sheet material is subjected to a first-stage aging treatment and a second-stage aging treatment in sequence to obtain a stress-relieved aluminum alloy sheet material. The first-stage aging treatment is carried out at a temperature of 120℃ for 4 hours, and the second-stage aging treatment is carried out at a temperature of 170℃ for 8 hours.

[0074] Example 4

[0075] This embodiment provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, including the following steps:

[0076] S1: The aluminum alloy sheet to be treated is solution treated at 480℃ for 2 hours. After the solution treatment, it is quickly quenched to obtain a quenched aluminum alloy sheet. The quenching medium in this step is water, and the quenching transfer time is 9 seconds.

[0077] S2: A multi-roller straightener is used to perform initial leveling of the quenched aluminum alloy sheet, with a reduction of 0.6%.

[0078] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process. The cold pressing deformation is 53% of the total cold pressing deformation, and the first cold-pressed sheet is obtained.

[0079] S4: The first-pass cold-pressed sheet is rotated 92° around the rotation axis, and then subjected to a second cold-pressing process. The cold-pressing deformation is 47% of the total cold-pressing deformation, resulting in a multi-directional cold-pressed sheet. Specifically, the rotation axis is perpendicular to the surface of the first-pass cold-pressed sheet. In steps S3 and S4, the total cold-pressing deformation of the first and second cold-pressing processes is 4.2% of the initial thickness of the aluminum alloy sheet. The temperature for both cold-pressing processes is 22℃, and the processing time is 31s for both.

[0080] S5: A high-precision straightening machine is used to perform secondary leveling on the multi-directional cold-pressed sheet material, with a reduction of 0.17%, to obtain a flat sheet material.

[0081] S6: The flat sheet material is subjected to a first-stage aging treatment and a second-stage aging treatment in sequence to obtain a stress-relieved aluminum alloy sheet material. The first-stage aging treatment is carried out at a temperature of 108℃ for 5 hours, and the second-stage aging treatment is carried out at a temperature of 168℃ for 10 hours.

[0082] Example 5

[0083] This embodiment provides a method for rapidly reducing residual stress in aluminum alloy plates after quenching, including the following steps:

[0084] S1: The aluminum alloy sheet to be treated is solution treated at 470℃ for 1.8 hours. After solution treatment, it is quickly quenched to obtain a quenched aluminum alloy sheet. The quenching medium in this step is water, and the quenching transfer time is 15 seconds.

[0085] S2: A multi-roller straightener is used to perform initial leveling of the quenched aluminum alloy sheet, with a reduction of 0.8%.

[0086] S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process. The cold pressing deformation is 57% of the total cold pressing deformation, and the first cold-pressed sheet is obtained.

[0087] S4: The first-pass cold-pressed sheet is rotated 88° around the rotation axis, and then subjected to a second cold-pressing process. The cold-pressing deformation is 43% of the total cold-pressing deformation, resulting in a multi-directional cold-pressed sheet. Specifically, the rotation axis is perpendicular to the surface of the first-pass cold-pressed sheet. In steps S3 and S4, the total cold-pressing deformation of the first and second cold-pressing processes is 4.1% of the initial thickness of the aluminum alloy sheet. The temperature for both cold-pressing processes is 24℃, and the processing time is 30 seconds for both.

[0088] S5: A high-precision straightening machine is used to perform secondary leveling on the multi-directional cold-pressed sheet material, with a reduction of 0.22%, to obtain a flat sheet material.

[0089] S6: The flat sheet material is subjected to a first-stage aging treatment and a second-stage aging treatment in sequence to obtain a stress-relieved aluminum alloy sheet material. The temperature of the first-stage aging treatment is 115℃ and the time is 4 hours, and the temperature of the second-stage aging treatment is 159℃ and the time is 11 hours.

[0090] Comparative Example 1

[0091] This comparative example provides a method for reducing residual stress during quenching of aluminum alloy plates. The difference from Example 1 is that step S4 is not performed.

[0092] Comparative Example 2

[0093] This comparative example provides a method for reducing residual stress in aluminum alloy plates after quenching. The difference from Example 1 is that the first-stage aging treatment is not performed in step S6.

[0094] Comparative Example 3

[0095] This comparative example provides a method for reducing residual stress during quenching of aluminum alloy plates. The difference from Example 1 is that in steps S3 and S4, the total cold pressing deformation is increased to 8%.

[0096] The performance of the aluminum alloy sheet products (all 6xxx series aluminum alloy sheets) prepared in Examples 1-5 and Comparative Examples 1-3 was tested and statistically analyzed, and Table 1 was obtained.

[0097] Table 1. Performance statistics of aluminum alloy sheets prepared in Examples 1-5 and Comparative Examples 1-3

[0098]

[0099]

[0100] Table 1 shows that Examples 1-5 all achieved high residual stress relief rates, excellent plate straightness, and good comprehensive mechanical properties. In Comparative Example 1, the residual stress relief rate was significantly reduced, and the plate straightness deteriorated, indicating that a single cold pressing can only primarily eliminate stress in one direction, leading to anisotropy. Although Comparative Example 2 had a acceptable stress relief rate, its yield strength and tensile strength were lower than those of Examples 1-5. This suggests that the lack of a low-temperature aging stage may prevent the formation of sufficient and dense GP zones as precipitation nuclei, resulting in coarsening and uneven distribution of the final strengthening phase η'. Comparative Example 3 demonstrates that excessive cold pressing deformation leads to poor residual stress relief, and the large plastic deformation severely deteriorates the plate shape, causing a sharp deterioration in straightness and a significant decrease in elongation.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for rapidly reducing residual stress during quenching of aluminum alloy plates, characterized in that, Includes the following steps: S1: Perform solution hardening treatment on the aluminum alloy sheet to be treated to obtain the quenched aluminum alloy sheet: S2: Initial leveling treatment of quenched aluminum alloy sheet; S3: The aluminum alloy sheet after the initial flattening process is subjected to the first cold pressing process to obtain the first cold-pressed sheet. S4: The first-pass cold-pressed sheet is rotated 85-95° around the rotating axis, and then subjected to a second cold-pressing process to obtain a multi-directional cold-pressed sheet; wherein, the rotating axis is perpendicular to the surface of the first-pass cold-pressed sheet; the total cold-pressing deformation of the first and second cold-pressing processes is 4-5% of the initial thickness of the aluminum alloy sheet; S5: Perform a secondary leveling process on the multi-directional cold-pressed sheet to obtain a flat sheet; S6: Perform stepped aging treatment on flat sheet metal to obtain stress-relieved aluminum alloy sheet metal.

2. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S1, the aluminum alloy sheet to be treated is subjected to solution treatment at 460-520℃ for 1-4 hours. After the solution treatment is completed, quenching treatment is performed using water or a polymer aqueous solution as the quenching medium.

3. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S1, the quenching transfer time is ≤15s.

4. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S2, a multi-roller straightener is used for initial leveling, with a reduction of 0.5-1%.

5. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S3, the cold pressing deformation amount of the first cold pressing process is 50-60% of the total cold pressing deformation amount.

6. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S4, the cold pressing deformation amount of the second cold pressing process is 40-50% of the total cold pressing deformation amount.

7. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S5, the reduction amount of the secondary leveling process is 0.1-0.3%.

8. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S6, the tiered aging process includes the first-level aging process and the second-level aging process.

9. The method for rapidly reducing residual stress in quenching aluminum alloy plates according to claim 1, characterized in that, In step S6, the temperature of the first-stage aging treatment is 105-120℃ and the time is 4-8h; the temperature of the second-stage aging treatment is 155-170℃ and the time is 8-16h.

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