Production method for avoiding flaw detection and crystal penetration of 2XXX aluminum alloy T351 state plate
By employing a segmented multi-pass rolling process and optimizing the alloy composition, the problem of transgranular flaw detection in 2XXX aluminum alloy sheets has been solved, achieving a high pass rate and excellent mechanical properties, making them suitable for applications in high-end fields such as aerospace.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-04-07
AI Technical Summary
In the existing production process of 2XXX aluminum alloy T351 state plates, unreasonable rolling results in coarse grains and poor microstructure uniformity, which leads to transgranular phenomena during flaw detection, affecting the product qualification rate and limiting its application in high-end fields.
By adopting a segmented multi-pass rolling process, combined with alloy composition optimization and heat treatment, and through segmented multi-pass rolling, cold rolling, solution treatment and aging treatment, the reduction rate, rate and temperature are precisely controlled to achieve grain refinement and microstructure homogenization, and to avoid cross-grain flaw detection.
It effectively avoids crystal penetration during flaw detection, achieving a flaw detection pass rate of over 99%. The sheet material boasts excellent mechanical properties and is suitable for industrial production in high-end fields such as aerospace.
Smart Images
Figure CN121802209A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aluminum alloy processing technology, specifically relating to a production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 state plates. Background Technology
[0002] 2XXX series aluminum alloys, with Al-Cu-Mg as the main alloying system, possess high strength, good corrosion resistance, and processing performance, and are widely used in critical fields such as aerospace, rail transportation, and military industry. These plates require rigorous non-destructive testing after production to identify internal defects and ensure safe use. However, in existing production processes, due to unreasonable rolling process design, the plates often exhibit coarse grains and poor microstructure uniformity, leading to transgranular phenomena during flaw detection. This severely impacts product yield and limits their application in high-end fields.
[0003] In existing technologies, solutions to the transgranularity problem in flaw detection of 2XXX aluminum alloy T351 state plates mostly focus on composition adjustment or homogenization optimization, with insufficient attention paid to the rolling process. For example, some methods improve the microstructure by increasing the content of grain-refining elements, but excessive elements can easily form coarse second phases, which reduces mechanical properties; other methods use a single reduction rate rolling, which makes it difficult to balance grain refinement and microstructure homogenization, and the risk of transgranularity remains. Therefore, designing a production method that focuses on optimizing the rolling process and coordinates composition control, heat treatment, and other aspects is key to solving the transgranularity problem in flaw detection of 2XXX aluminum alloy plates. Summary of the Invention
[0004] The purpose of this invention is to solve the problems mentioned above and to provide a production method for 2XXX aluminum alloy T351 state plates that avoids transgranular flaw detection.
[0005] A production method for 2XXX aluminum alloy T351 temper sheet to avoid transgranular flaw detection, comprising the following steps:
[0006] I. Batching and Smelting / Casting:
[0007] Raw materials are weighed according to the following alloy element mass fractions: Cu: 4.0%~5.0%, Mg: 0.4%~1.0%, Mn: 0.20%~0.45%, Ti: 0.02%~0.10%, Zr: 0.05%~0.20%, with the remainder being Al and impurities with a total content of ≤0.15%. The raw materials are then smelted and cast to obtain ingots.
[0008] II. Homogenization treatment and segmented multi-pass rolling:
[0009] The above-mentioned ingots undergo three-stage homogenization treatment, followed by pre-treatment before rolling, then heating and holding at a certain temperature. After exiting the furnace, they are subjected to segmented multi-pass rolling to obtain plates.
[0010] III. Cold rolling:
[0011] The above-mentioned sheet material is further rolled using a cold rolling mill, with the total reduction rate controlled at 15%~25%, to obtain cold-rolled sheet material;
[0012] IV. Solution treatment, stretching, and aging:
[0013] The above-mentioned cold-rolled sheet is subjected to solution treatment, followed by stretching and aging treatment to obtain the finished sheet, which is the 2XXX aluminum alloy T351 state sheet, thus completing the production method.
[0014] Furthermore, the smelting and casting described in step one involves: feeding the raw materials into a smelting furnace and smelting them at 730~760℃, while introducing 0.3~0.5m... 3 Argon refining is carried out for 20-30 minutes per hour, followed by casting using a semi-continuous casting process at a casting speed of 80-120 mm / min and a cooling water volume of 120-180 m³ / h. 3 / h.
[0015] Furthermore, the three-stage homogenization process described in step two is as follows: in the first stage, the temperature is increased to 400~405℃ at a rate of 40℃ / h and held for 3~5h; in the second stage, the temperature is increased to 445~460℃ at a rate of 40℃ / h and held for 15~24h; in the third stage, the temperature is increased to 492~496℃ at a rate of 10℃ / h and held for 12~20h; and finally, the furnace is cooled.
[0016] Furthermore, in step two, the pre-treatment before rolling is as follows: after the three-stage homogenization treatment, the ingot is sawn to remove 50~100mm from the head and tail, and the surface is milled to remove 5~10mm.
[0017] Furthermore, the heating and heat preservation described in step two involves maintaining the temperature at 420~430℃ for 2~3 hours.
[0018] Furthermore, the segmented multi-pass rolling process described in step two is as follows:
[0019] Passes 1-3 are for roughing rolling: single-pass reduction rate 8%-12%, rolling speed 0.8-1.2m / s;
[0020] Passes 4 through 10 are intermediate rolling: even-numbered passes have a reduction rate of 15% to 18% and a speed of 1.0 to 1.5 m / s, while odd-numbered passes have a reduction rate of 6% to 9% and a speed of 0.6 to 0.9 m / s.
[0021] Passes 11 to 18 are finishing rolling: the single-pass reduction rate is increased to 17% to 22%, the speed is 1.2 to 1.8 m / s, and the final rolling temperature is 410 to 425℃;
[0022] Rolling process control: The surface temperature of the plate during rolling is ≥380℃, and the interval between adjacent passes is ≤3min.
[0023] Furthermore, in step three, rolling is continued using a cold rolling mill, as detailed below:
[0024] If the thickness of the board is ≤50mm, the total number of passes should be controlled within 7 passes;
[0025] If the thickness of the board is >50~100mm, the total number of passes should be controlled within 9 passes;
[0026] If the thickness of the board is >100~150mm, the total number of passes should be controlled within 11 passes;
[0027] If the thickness of the board is >150~200mm, the total number of passes should be controlled within 13 passes.
[0028] Furthermore, the solution treatment described in step four involves holding the solution at 490~540℃ for 1~2 hours, followed by high-pressure water mist quenching at 0.8~1.2MPa with a cooling rate ≥20℃ / s.
[0029] Furthermore, the stretching described in step four: stretching is performed within 4 hours after solution treatment, with a stretching speed ≤2.5mm / s and a stretching amount ≤2.2%.
[0030] Furthermore, the aging process described in step four: natural aging time ≥ 96h.
[0031] Advantages of this invention:
[0032] 1. With rolling process as the core, through segmented multi-pass "billing-intermediate-finishing" precise control, through billet energy storage, intermediate "large reduction + small reduction" alternating mode, and finishing rolling gradient pressure segmented rolling, taking into account the dynamic recovery and refinement of grains, combined with the synergistic optimization of reduction rate, speed and temperature, effectively refines the grains of 2XXX aluminum alloy plates, achieves grain refinement and microstructure homogenization, fundamentally avoids the phenomenon of transgranular flaw detection, and the flaw detection pass rate reaches over 99%;
[0033] 2. Collaboratively optimize alloy composition and homogenization treatment, and increase cold rolling, controlling the cold rolling amount to 15~25%. While preventing transgranular bonding, the mechanical properties of the sheet are guaranteed by normal solution treatment and aging processes, with tensile strength ≥480MPa, yield strength ≥420MPa, and elongation ≥12%.
[0034] 3. The stretching process is controlled within 4 hours of solution treatment. Stretching can effectively reduce the natural aging strength. At the same time, the stretching amount and stretching speed are controlled to reduce surface flaws caused by excessive speed and excessive stretching amount.
[0035] 4. The rolling process does not require complex equipment modifications, has strong process operability, is suitable for industrial production in high-end fields such as aerospace, is suitable for large-scale industrial production, and has broad application prospects. Attached Figure Description
[0036] Figure 1 This is a physical image of the 2XXX aluminum alloy T351 state plate prepared in Example 1. Detailed Implementation
[0037] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.
[0038] Specific Implementation Method 1: This implementation method describes a production method for 2XXX aluminum alloy T351 temper sheet to avoid transgranular flaw detection, which is carried out according to the following steps:
[0039] I. Batching and Smelting / Casting:
[0040] Raw materials are weighed according to the following alloy element mass fractions: Cu: 4.0%~5.0%, Mg: 0.4%~1.0%, Mn: 0.20%~0.45%, Ti: 0.02%~0.10%, Zr: 0.05%~0.20%, with the remainder being Al and impurities with a total content of ≤0.15%. The raw materials are then smelted and cast to obtain ingots.
[0041] II. Homogenization treatment and segmented multi-pass rolling:
[0042] The above-mentioned ingots undergo three-stage homogenization treatment, followed by pre-treatment before rolling, then heating and holding at a certain temperature. After exiting the furnace, they are subjected to segmented multi-pass rolling to obtain plates.
[0043] III. Cold rolling:
[0044] The above-mentioned sheet material is further rolled using a cold rolling mill, with the total reduction rate controlled at 15%~25%, to obtain cold-rolled sheet material;
[0045] IV. Solution treatment, stretching, and aging:
[0046] The above-mentioned cold-rolled sheet is subjected to solution treatment, followed by stretching and aging treatment to obtain the finished sheet, which is the 2XXX aluminum alloy T351 state sheet, thus completing the production method.
[0047] In step one of this embodiment, Ti and Zr work synergistically to achieve grain refinement, and the total impurity content is strictly controlled to ≤0.15%.
[0048] The ingot obtained in step one of this embodiment is Φ420mm.
[0049] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that, in step one, the smelting and casting process involves: feeding the raw materials into a smelting furnace and smelting them at 730~760℃, refining them with argon gas at a flow rate of 0.3~0.5 m³ / h for 20~30 minutes, and then using a semi-continuous casting process with a casting speed of 80~120 mm / min and a cooling water flow rate of 120~180 m³ / h. 3 / h. Other steps and parameters are the same as in Specific Implementation Method 1.
[0050] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the heating and heat preservation step two involves maintaining the temperature at 420~430℃ for 2~3 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0051] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the segmented multi-pass rolling process described in step two is as follows:
[0052] Passes 1-3 are for roughing rolling: single-pass reduction rate 8%-12%, rolling speed 0.8-1.2m / s;
[0053] Passes 4 through 10 are intermediate rolling: even-numbered passes have a reduction rate of 15% to 18% and a speed of 1.0 to 1.5 m / s, while odd-numbered passes have a reduction rate of 6% to 9% and a speed of 0.6 to 0.9 m / s.
[0054] Passes 11 to 18 are finishing rolling: the single-pass reduction rate is increased to 17% to 22%, the speed is 1.2 to 1.8 m / s, and the final rolling temperature is 410 to 425℃;
[0055] Rolling process control: The surface temperature of the plate during rolling is ≥380℃, and the interval between adjacent passes is ≤3min.
[0056] The other steps and parameters are the same as in Specific Implementation Method 1.
[0057] In this embodiment, the purpose of the initial rolling is to rapidly roll and accumulate sufficient stored energy to provide power for subsequent grain refinement.
[0058] Intermediate rolling employs an alternating pattern of "large reduction + small reduction". Even-numbered passes have a reduction rate of 15%~18% and a speed of 1.0~1.5m / s, the purpose of which is to maintain dynamic recovery through large reduction and avoid grain growth; odd-numbered passes have a reduction rate of 6%~9% and a speed of 0.6~0.9m / s, the purpose of which is to refine the formed grains and improve the uniformity of the microstructure.
[0059] The purpose of precision rolling is to ensure that the grains of the plate are fine and uniform after forming.
[0060] The purpose of rolling process control is to avoid abnormal grain growth caused by prolonged high temperature, while avoiding additional shutdowns for temperature maintenance and ensuring batch performance consistency.
[0061] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the three-stage homogenization treatment in step two is as follows: The first stage involves heating at a rate of 40℃ / h to 400~405℃ and holding for 3~5 hours; the second stage involves heating at a rate of 40℃ / h to 445~460℃ and holding for 15~24 hours; the third stage involves heating at a rate of 10℃ / h to 492~496℃ and holding for 12~20 hours; finally, the furnace is cooled. Other steps and parameters are the same as in Specific Implementation Method One.
[0062] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that, in step two, the pre-treatment before rolling involves sawing off 50-100mm from the head and tail of the ingot after three-stage homogenization, and milling off 5-10mm from the surface. Other steps and parameters are the same as in Specific Implementation Method One.
[0063] In this embodiment, sawing removes the head and tail to remove unstable parts; milling removes the anti-segregation layer and oxide scale.
[0064] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that, in step three, a cold rolling mill is used to continue rolling, as detailed below:
[0065] If the thickness of the board is ≤50mm, the total number of passes should be controlled within 7 passes;
[0066] If the thickness of the board is >50~100mm, the total number of passes should be controlled within 9 passes;
[0067] If the thickness of the board is >100~150mm, the total number of passes should be controlled within 11 passes;
[0068] If the thickness of the board is >150~200mm, the total number of passes should be controlled within 13 passes.
[0069] The other steps and parameters are the same as in Specific Implementation Method 1.
[0070] In this embodiment, the number of cold rolling passes is controlled for different plate thicknesses in order to reduce the serious impact on the surface structure of the material caused by too few passes or too many single passes.
[0071] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the solution treatment in step four involves: solution treatment at 490~540℃ for 1~2 hours, followed by high-pressure water mist quenching at 0.8~1.2MPa with a cooling rate ≥20℃ / s. Other steps and parameters are the same as in Specific Implementation Method One.
[0072] The purpose of solution treatment in this embodiment is to ensure the supersaturation of the matrix.
[0073] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that the stretching described in step four is performed within 4 hours after solution treatment, with a stretching speed ≤2.5mm / s and a stretching amount ≤2.2%. Other steps and parameters are the same as in Specific Implementation Method One.
[0074] In this embodiment, the purpose of stretching is to avoid excessive stretching speed and amount, which could lead to transgranular surface flaw detection.
[0075] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that the aging process described in step four involves a natural aging time of ≥96 hours. All other steps and parameters are the same as in Specific Implementation Method One.
[0076] The purpose of the aging treatment in this embodiment is to avoid the continuous distribution of grain boundary precipitates, reduce stress concentration, and further eliminate the risk of transgranular precipitation.
[0077] The beneficial effects of the present invention are verified through the following embodiments:
[0078] The following description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0079] Example 1:
[0080] A production method for 2XXX aluminum alloy T351 temper sheet to avoid transgranular flaw detection, comprising the following steps:
[0081] I. Batching and Smelting / Casting:
[0082] Raw materials are weighed according to the following alloy element mass fractions: Cu: 4.5%, Mg: 0.7%, Mn: 0.35%, Ti: 0.06%, Zr: 0.12%, with the remainder being Al and impurities with a total content of ≤0.12%. The materials are then melted and cast to obtain ingots.
[0083] II. Homogenization treatment and segmented multi-pass rolling:
[0084] The above-mentioned ingots undergo three-stage homogenization treatment, followed by pre-treatment before rolling, then heating and holding at a certain temperature. After exiting the furnace, they are subjected to segmented multi-pass rolling to obtain plates.
[0085] III. Cold rolling:
[0086] The above-mentioned sheet material is further rolled using a cold rolling mill, with the total reduction rate controlled at 20%, to obtain cold-rolled sheet material;
[0087] IV. Solution treatment, stretching, and aging:
[0088] The above-mentioned cold-rolled sheet is subjected to solution treatment, followed by stretching and aging treatment to obtain the finished sheet, which is the 2XXX aluminum alloy T351 state sheet, thus completing the production method.
[0089] In step one of this embodiment, the smelting and casting process involves: feeding the raw materials into a smelting furnace and smelting them at 745°C, while introducing 0.4m³ of gas. 3 Argon refining was performed for 25 minutes per hour, followed by casting using a semi-continuous casting process at a casting speed of 100 mm / min and a cooling water volume of 150 m³ / h. 3 / h.
[0090] The three-stage homogenization process described in step two of this embodiment is as follows: in the first stage, the temperature is increased to 402°C at a rate of 40°C / h and held for 4 hours; in the second stage, the temperature is increased to 450°C at a rate of 40°C / h and held for 20 hours; in the third stage, the temperature is increased to 494°C at a rate of 10°C / h and held for 16 hours; and finally, the furnace is cooled.
[0091] In step two of this embodiment, the pre-treatment before rolling is as follows: after three-stage homogenization, the ingot is sawn to remove 80mm from the head and tail, and the surface is milled to remove 8mm.
[0092] The heating and heat preservation step in this embodiment involves maintaining the temperature at 425°C for 2.5 hours.
[0093] The segmented multi-pass rolling process described in step two of this embodiment is as follows:
[0094] Passes 1-3 are for roughing rolling: single pass reduction rate 10%, rolling speed 1.0m / s;
[0095] Passes 4 through 10 are intermediate rolling: passes 4, 6, 8, and 10 have a reduction rate of 16% and a speed of 1.2 m / s, while passes 5, 7, and 9 have a reduction rate of 8% and a speed of 0.7 m / s.
[0096] Passes 11-15 are finishing rolling: single pass reduction rate 17%→19%→20%→21%→22%, speed 1.5m / s, final rolling temperature 418℃;
[0097] Rolling process control: The surface temperature of the plate during rolling is ≥380℃, and the interval between adjacent passes is ≤3min.
[0098] In step three of this embodiment, a cold rolling mill is used to continue rolling, with a total of 5 passes.
[0099] The solution treatment described in step four of this embodiment involves solution treatment at 510°C for 1.5 hours, followed by high-pressure water mist quenching at 1.0 MPa with a cooling rate ≥20°C / s.
[0100] The stretching described in step four of this embodiment is as follows: stretching is performed within 4 hours after solution treatment, with a stretching speed of 2 mm / s and a stretching amount of 2.0%.
[0101] The aging process described in step four of this embodiment is: natural aging ≥ 96h.
[0102] The ingot obtained in step one of this embodiment is Φ420mm.
[0103] The 2XXX aluminum alloy T351 state plate prepared in this embodiment has a thickness of 35mm. The flaw detection showed no transgranular phenomenon, and the pass rate was 100%. Mechanical property tests showed a tensile strength of 495MPa, a yield strength of 432MPa, and an elongation of 13.5%.
[0104] Example 2:
[0105] A production method for 2XXX aluminum alloy T351 temper sheet to avoid transgranular flaw detection, comprising the following steps:
[0106] I. Batching and Smelting / Casting:
[0107] Raw materials are weighed according to the following ratio: Cu: 4.2%, Mg: 0.5%, Mn: 0.25%, Ti: 0.04%, Zr: 0.08%, with the remainder being Al and impurities with a total content of ≤0.10%. The materials are then melted and cast to obtain ingots.
[0108] II. Homogenization treatment and segmented multi-pass rolling:
[0109] The above-mentioned ingots undergo three-stage homogenization treatment, followed by pre-treatment before rolling, then heating and holding at a certain temperature. After exiting the furnace, they are subjected to segmented multi-pass rolling to obtain plates.
[0110] III. Cold rolling:
[0111] The above-mentioned sheet material is further rolled using a cold rolling mill, with the total reduction rate controlled at 20%, to obtain cold-rolled sheet material;
[0112] IV. Solution treatment, stretching, and aging:
[0113] The above-mentioned cold-rolled sheet is subjected to solution treatment, followed by stretching and aging treatment to obtain the finished sheet, which is the 2XXX aluminum alloy T351 state sheet, thus completing the production method.
[0114] In step one of this embodiment, the smelting and casting process involves: feeding the raw materials into a smelting furnace and smelting them at 765°C, while introducing 0.3m³ of gas. 3Argon refining was performed for 20 minutes per hour, followed by casting using a semi-continuous casting process at a casting speed of 90 mm / min and a cooling water volume of 130 m³ / h. 3 / h.
[0115] The three-stage homogenization process described in step two of this embodiment is as follows: in the first stage, the temperature is increased to 400℃ at a rate of 40℃ / h and held for 3 hours; in the second stage, the temperature is increased to 445℃ at a rate of 40℃ / h and held for 18 hours; in the third stage, the temperature is increased to 492℃ at a rate of 10℃ / h and held for 14 hours; and finally, the furnace is cooled.
[0116] In step two of this embodiment, the pre-treatment before rolling is as follows: after three-stage homogenization treatment, the ingot is sawn to remove 60mm from the head and tail, and the surface is milled to remove 6mm.
[0117] In step two of this embodiment, the heating and heat preservation are carried out at 420°C for 2 hours.
[0118] The segmented multi-pass rolling process described in step two of this embodiment is as follows:
[0119] Passes 1-3 are for roughing rolling: single-pass reduction rate is 9%, and rolling speed is 0.9 m / s;
[0120] Passes 4 through 10 are intermediate rolling: passes 4, 6, 8, and 10 have a reduction rate of 15% and a speed of 1.1 m / s, while passes 5, 7, and 9 have a reduction rate of 7% and a speed of 0.6 m / s.
[0121] Passes 11-16 are finishing rolling: single pass reduction rate 17%→18%→19%→20%→21%, speed 1.3m / s, final rolling temperature 412℃;
[0122] Rolling process control: The surface temperature of the plate during rolling is ≥380℃, and the interval between adjacent passes is ≤3min.
[0123] In step three of this embodiment, a cold rolling mill is used to continue rolling, with a total of 5 passes.
[0124] The solution treatment described in step four of this embodiment involves solution treatment at 495°C for 1 hour, followed by high-pressure water mist quenching at 0.9MPa with a cooling rate ≥20°C / s.
[0125] The stretching described in step four of this embodiment is performed within 4 hours after solution treatment, with a stretching speed of 1.5 mm / s and a stretching amount of 1.9%.
[0126] The aging process described in step four of this embodiment is: natural aging ≥ 96h.
[0127] The ingot obtained in step one of this embodiment is Φ420mm.
[0128] The 2XXX aluminum alloy T351 state plate prepared in this embodiment has a thickness of 30mm. The flaw detection showed no transgranular phenomenon, and the pass rate was 99.5%. Mechanical property tests showed a tensile strength of 482MPa, a yield strength of 425MPa, and an elongation of 12.8%.
[0129] In summary, this invention focuses on designing a segmented, multi-pass rolling process to precisely control the reduction rate, rolling speed, and final rolling temperature at each stage. It also incorporates cold rolling and controls the stretching parameters, combined with composition regulation and homogenization treatment, to achieve grain refinement and microstructure homogenization. This fundamentally avoids transgranular defects during flaw detection and ensures the mechanical properties of the sheet metal.
Claims
1. A production method for 2XXX aluminum alloy T351 temper sheet to avoid transgranular flaw detection, characterized in that, It proceeds in the following steps: I. Batching and Smelting / Casting: Raw materials are weighed according to the following alloy element mass fractions: Cu: 4.0%~5.0%, Mg: 0.4%~1.0%, Mn: 0.20%~0.45%, Ti: 0.02%~0.10%, Zr: 0.05%~0.20%, with the remainder being Al and impurities with a total content of ≤0.15%. The raw materials are then smelted and cast to obtain ingots. II. Homogenization treatment and segmented multi-pass rolling: The above-mentioned ingots undergo three-stage homogenization treatment, followed by pre-treatment before rolling, then heating and holding at a certain temperature. After exiting the furnace, they are subjected to segmented multi-pass rolling to obtain plates. III. Cold rolling: The above-mentioned sheet material is further rolled using a cold rolling mill, with the total reduction rate controlled at 15%~25%, to obtain cold-rolled sheet material; IV. Solution treatment, stretching, and aging: The above-mentioned cold-rolled sheet is subjected to solution treatment, followed by stretching and aging treatment to obtain the finished sheet, which is the 2XXX aluminum alloy T351 state sheet, thus completing the production method.
2. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The smelting and casting described in step one: The raw materials are fed into a smelting furnace and smelted at 730~760℃, while 0.3~0.5m³ of steam is introduced. 3 Argon refining is carried out for 20-30 minutes per hour, followed by casting using a semi-continuous casting process at a casting speed of 80-120 mm / min and a cooling water volume of 120-180 m³ / h. 3 / h.
3. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The three-stage homogenization process described in step two is as follows: in the first stage, the temperature is increased to 400~405℃ at a rate of 40℃ / h and held for 3~5h; in the second stage, the temperature is increased to 445~460℃ at a rate of 40℃ / h and held for 15~24h; in the third stage, the temperature is increased to 492~496℃ at a rate of 10℃ / h and held for 12~20h; and finally, the furnace is cooled.
4. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, Pre-treatment before rolling in step two: After the three-stage homogenization process, the ingot is sawn to remove 50-100mm from the head and tail, and milled to remove 5-10mm from the surface.
5. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The heating and heat preservation step 2 involves maintaining the temperature at 420-430℃ for 2-3 hours.
6. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The segmented multi-pass rolling process described in step two is as follows: Passes 1-3 are for roughing rolling: single-pass reduction rate 8%-12%, rolling speed 0.8-1.2m / s; Passes 4 through 10 are intermediate rolling: even-numbered passes have a reduction rate of 15% to 18% and a speed of 1.0 to 1.5 m / s, while odd-numbered passes have a reduction rate of 6% to 9% and a speed of 0.6 to 0.9 m / s. Passes 11 to 18 are finishing rolling: the single-pass reduction rate is increased to 17% to 22%, the speed is 1.2 to 1.8 m / s, and the final rolling temperature is 410 to 425℃; Rolling process control: The surface temperature of the plate during rolling is ≥380℃, and the interval between adjacent passes is ≤3min.
7. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, Step three involves continuing rolling using a cold rolling mill, as detailed below: If the thickness of the board is ≤50mm, the total number of passes should be controlled within 7 passes; If the thickness of the board is >50~100mm, the total number of passes should be controlled within 9 passes; If the thickness of the board is >100~150mm, the total number of passes should be controlled within 11 passes; If the thickness of the board is >150~200mm, the total number of passes should be controlled within 13 passes.
8. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The solution treatment described in step four involves holding the solution at 490~540℃ for 1~2 hours, followed by high-pressure water mist quenching at 0.8~1.2MPa with a cooling rate ≥20℃ / s.
9. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The stretching described in step four: Stretching shall be performed within 4 hours after solution treatment, with a stretching speed ≤2.5mm / s and a stretching amount ≤2.2%.
10. The production method for avoiding transgranular flaw detection of 2XXX aluminum alloy T351 tempered sheet according to claim 1, characterized in that, The aging process described in step four: natural aging time ≥ 96h.