Preparation method of welding crack resistant 6082 aluminum alloy forge piece

Abstract

The invention provides a preparation method of a 6082 aluminum alloy forge piece resistant to welding cracks, and belongs to the technical field of aluminum alloy forging.The preparation method comprises the following steps that S1, an aluminum alloy ingot is subjected to extrusion forming after being subjected to annealing homogenization treatment, and an aluminum alloy bar is obtained; s2, the aluminum alloy bar is heated before forging under the condition of 500-520 DEG C and then is subjected to upsetting blank making immediately, and a blank is obtained; the blank is immediately transferred into a pre-forging die to be pre-forged and then immediately transferred into a finish-forging die to be finish-forged, trimming and water cooling are conducted after finish-forging is finished, and a die forging is obtained; wherein the finish forging temperature is controlled to be higher than or equal to 420 DEG C, and the roughness Ra of the pre-forging die and the finish forging die is 0.4-1.6 microns; and S3, the die forging is subjected to solution treatment and aging treatment, and the 6082 aluminum alloy forging resistant to welding cracks is obtained. According to the method, through full-process optimization regulation and control, grain coarsening of the forge piece is restrained, and microcracks in a welding heat affected zone are avoided.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy forging technology, and specifically to a method for preparing 6082 aluminum alloy forgings resistant to welding cracks. Background Technology

[0002] 6082-T6 forged aluminum alloy, due to its high strength, corrosion resistance, and heat-treatable strengthening properties, has become the preferred material for load-bearing structural components in aerospace, rail transportation, and heavy equipment. However, with the increasing adoption of large-scale integrated and thin-walled lightweight designs, welded connections or laser additive repair have become indispensable links in the manufacturing chain. In actual production, this alloy is highly susceptible to intergranular microcracks in the weld heat-affected zone (HAZ), including intergranular liquefaction cracks, hydrogen-induced cracks, and thermal stress cracks, leading to a significant decrease in the finished product yield and persistently high rework and scrap costs.

[0003] Traditional forging processes have the following problems: forgings exhibit coarse and unevenly distributed grains, resulting in high sensitivity to grain boundary liquefaction during welding; the lack of rational flow line distribution exacerbates the anisotropy of welding thermal stress; residual tensile stress promotes the propagation of hydrogen-induced cracks; and the alloy is highly susceptible to intergranular microcracks in the weld heat-affected zone (HAZ).

[0004] Therefore, it is urgent to develop new forging processes to fundamentally suppress microcracks in the heat-affected zone of 6082 aluminum alloy welding, so as to meet the urgent needs of high-end load-bearing structures for high reliability and low-defect manufacturing. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a method for preparing 6082 aluminum alloy forgings resistant to welding cracks, aiming to solve the technical problem that forgings obtained by existing forging processes are prone to intergranular microcracks in the weld heat-affected zone (HAZ).

[0006] In a first aspect, the present invention provides a method for preparing a 6082 aluminum alloy forging resistant to welding cracks, comprising the following steps: S1. Pretreatment: After annealing and homogenizing the aluminum alloy ingot, it is extruded to obtain aluminum alloy bar stock. S2. Forging: The aluminum alloy bar is preheated at 500~520℃ and then immediately upset to obtain a billet. The billet is immediately transferred to a pre-forging die for pre-forging, and then immediately transferred to a final forging die for final forging. After final forging, the edges are trimmed and water-cooled to obtain the die forging. The final forging temperature is controlled at ≥420℃, and the surface roughness Ra of the pre-forging die and the final forging die is 0.4~1.6μm. S3. Heat treatment: The die forgings are subjected to solution treatment and aging treatment to obtain 6082 aluminum alloy forgings that are resistant to welding cracks.

[0007] Preferably, the aluminum alloy ingot comprises the following components by weight percentage: Si 0.7%~1.1%, Mg 0.6%~1.2%, Mn 0.5%~0.8%, Fe 0.1%~0.3%, Cr 0.1%~0.25%, Cu≤0.1%, Zn≤0.2%, Ti≤0.1%, and the balance Al.

[0008] Preferably, the ratio of Mg to Si in the aluminum alloy ingot composition is 1.0 to 1.3.

[0009] Preferably, the annealing homogenization treatment specifically involves holding the aluminum alloy ingot at 530~550℃ for 4~12 hours.

[0010] Preferably, the pre-forging heating time does not exceed 6 hours.

[0011] Preferably, the pre-forging die and the final forging die should be preheated to 180~220℃ before use and uniformly sprayed with a release agent.

[0012] Preferably, the streamline direction of the forging is parallel to the main load direction and the bevel direction; the distance between the parting surface of the forging and the weld is ≥10mm.

[0013] Preferably, the solution treatment specifically involves: holding the die forging at 535~550℃ for a certain time T, followed by water quenching; the time T is: for every 20 mm thickness of the die forging, it needs to be held at the solution temperature for 15~25 min, plus an additional safety margin of 10~15 min.

[0014] Preferably, the water quenching time is 10~12 minutes and the water temperature is 15~45℃.

[0015] Preferably, the aging treatment specifically involves heat treatment at 190℃ for 2 hours.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention optimizes and controls the entire process from raw materials to forging and heat treatment. By leveraging the synergistic effect of the Mg / Si ratio and Mn / Fe / Cr microalloying, it suppresses the formation of coarse grains. Through precise control of forging temperature and die roughness, it suppresses grain coarsening. Appropriate solution treatment and aging treatment are used to eliminate residual stress and improve the strength and hardness of the forgings.

[0017] This invention enables the grain size of the weld zone of the finished forging to be controlled below 100 micrometers, while limiting the size of the second phase particles to within 5 micrometers. This releases a large amount of residual tensile stress, effectively suppresses the generation of microcracks in the heat-affected zone of 6082 aluminum alloy welding, and thus comprehensively improves the reliability and service life of the product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the forging structure design in Embodiment 1 of the present invention; Figure 2 The image shows the welded HAZ metallographic image of the 6082 aluminum alloy forging obtained in Example 1 of this invention. Figure 3 The image shows the welded HAZ metallographic image of the 6082 aluminum alloy forging obtained in Example 2 of this invention. Figure 4 The image shows the welded HAZ metallographic image of the 6082 aluminum alloy forging obtained in Comparative Example 1 of this invention. Detailed Implementation

[0019] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0020] To address the technical problem that forgings obtained by existing forging processes are prone to intergranular microcracks in the weld heat-affected zone (HAZ), this invention provides a method for preparing 6082 aluminum alloy forgings resistant to weld cracks. By controlling the entire process (raw materials-forging-heat treatment), the method achieves uniform microstructure, streamline optimization, and residual stress control, resulting in forgings with good crack resistance during welding.

[0021] In a first aspect, embodiments of the present invention provide a method for preparing a 6082 aluminum alloy forging resistant to welding cracks, comprising the following steps: S1. Pretreatment: After annealing and homogenizing the aluminum alloy ingot, it is extruded to obtain aluminum alloy bar stock. S2. Forging: The aluminum alloy bar is preheated at 500~520℃ and then immediately upset to obtain a billet. The billet is immediately transferred to a pre-forging die for pre-forging, and then immediately transferred to a final forging die for final forging. After final forging, the edges are trimmed and water-cooled to obtain the die forging. The final forging temperature is controlled at ≥420℃, and the surface roughness Ra of the pre-forging die and the final forging die is 0.4~1.6μm. S3. Heat treatment: The die forgings are subjected to solution treatment and aging treatment to obtain 6082 aluminum alloy forgings that are resistant to welding cracks.

[0022] In the technical solution of this invention embodiment, the aluminum alloy bar is preheated at 500~520℃ and then immediately subjected to subsequent forging processes. No additional heat source is provided to heat the bar after preheating, effectively avoiding material performance degradation and cracking caused by repeated heating, thus ensuring the mechanical properties and resistance to welding cracks of the forging. During the transfer process, some heat is lost due to heat exchange between the forging and the air, but this is compensated by frictional heat generated between the forging and the die during forging. The magnitude of this frictional heat is closely related to the die roughness. The continuous forging cycle is approximately 1 minute, and the temperature at the end of the final forging is controlled to be ≥420℃. Fine grains and complete recrystallization are achieved by combining lower-temperature forging (≤520℃) with higher-temperature final forging (≥420℃): lower-temperature forging ensures that grain growth is avoided due to excessively high temperatures during forging and also ensures the smooth completion of the forging process; higher-temperature final forging ensures complete recrystallization after deformation, resulting in a stable microstructure.

[0023] Furthermore, in some embodiments, the aluminum alloy ingot comprises the following components by weight percentage: Si 0.7%~1.1%, Mg 0.6%~1.2%, Mn 0.5%~0.8%, Fe 0.1%~0.3%, Cr 0.1%~0.25%, Cu≤0.1%, Zn≤0.2%, Ti≤0.1%, and the balance Al.

[0024] Furthermore, in some embodiments, the Mg to Si ratio in the aluminum alloy ingot composition is 1.0 to 1.3.

[0025] In the technical solution of this invention embodiment, the formation of coarse grains is suppressed by controlling the Mg / Si ratio and the synergistic effect of Mn / Fe / Cr microalloying: Mg2Si precipitates as a fine dispersed phase, while excess Si combines with Fe / Mn / Cr to form a thermally stable dispersed phase (such as α-AlFeSi) to pin the grain boundaries, and Mn / Cr solute atoms adsorb at the grain boundaries to reduce the driving force for grain boundary migration and suppress the formation of coarse grains.

[0026] Furthermore, in some embodiments, the annealing homogenization treatment specifically involves holding the aluminum alloy ingot at 530~550℃ for 4~12 hours.

[0027] Furthermore, in some embodiments, if the ingot cross-sectional diameter is <200mm, the holding time is 4~6 hours; if the ingot cross-sectional diameter is 200~300mm, the holding time is 6~8 hours; if the ingot cross-sectional diameter is >300mm, the holding time is 8~12 hours.

[0028] In the technical solution of this invention embodiment, the aluminum alloy ingot is subjected to annealing and homogenization treatment in order to eliminate segregation.

[0029] Furthermore, in some embodiments, the pre-forging heating time does not exceed 6 hours.

[0030] Furthermore, in some embodiments, the pre-forging die and the final forging die need to be preheated to 180~220°C before use and uniformly sprayed with a release agent.

[0031] In the technical solution of this invention embodiment, preheating the pre-forging die and the final forging die before use can ensure the temperature stability of the die during the forging process and prevent defects such as cracks in the forging due to temperature differences; uniformly spraying the release agent to maintain the high gloss of the die and sufficient lubrication can reduce frictional heat and avoid excessive frictional heat causing the temperature of the forging to be too high, exceeding the pre-forging heating temperature and causing grain coarsening, thereby effectively controlling grain coarsening.

[0032] Furthermore, in some embodiments, the streamline direction of the forging is parallel to the main load direction and the bevel direction; the distance between the parting surface of the forging and the weld is ≥10mm.

[0033] In the technical solution of this invention embodiment, the invention also optimizes the forging structure design: the parting surface avoids the weld seam, and the streamline orientation is optimized (the streamline direction is parallel to the weld seam direction), which can reduce welding stress concentration.

[0034] Furthermore, in some embodiments, the solution treatment specifically involves: holding the forging at 535~550℃ for a certain time T, followed by water quenching; The time T is: for every 20 mm thickness of the die forging, it needs to be kept at the solution temperature for 15 to 25 minutes, plus an additional safety margin of 10 to 15 minutes.

[0035] Furthermore, in some embodiments, the water quenching time is 10-12 minutes, and the water temperature is 15-45°C.

[0036] Furthermore, in some embodiments, the aging treatment specifically involves heat treatment at 190°C for 2 hours.

[0037] In the technical solution of this invention, a higher solution temperature can increase the solubility of alloying elements in the aluminum matrix, resulting in better mechanical properties; a shorter and longer high-temperature aging process can ensure that the mechanical properties of the forgings meet the requirements, while saving energy and time, and greatly improving the efficiency of coordinated use between the solution furnace and the aging furnace.

[0038] In the technical solution of this invention embodiment, a short-time and efficient aging treatment is used to replace the traditional long-time treatment process, thereby improving efficiency and maintaining crack resistance.

[0039] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0040] Example 1 A method for preparing a 6082 aluminum alloy forging resistant to welding cracks includes the following steps: S1. An aluminum alloy ingot is obtained by smelting and casting according to the alloy ratio. The components of the aluminum alloy ingot, by mass percentage, include: Si 0.803%, Fe 0.215%, Cu 0.05%, Mn 0.628%, Mg 0.96% (Mg / Si=1.2), Cr 0.168%, Zn 0.013%, Ti 0.03%, with the balance being Al. S2. Ingot annealing and homogenization treatment: The aluminum alloy ingot obtained in step S1 is kept at 540℃ for 6 hours; after homogenization treatment, the ingot is extruded into bars, and the average grain size of the bars is measured to be 33μm. S3. Forging: The bar stock is placed in the pre-forging heating furnace and held at 520℃ for 2 hours. Then, it is immediately transferred to the upsetting cavity of the die for upsetting (the temperature after upsetting is measured to be around 493℃ using a contact thermometer). The upset billet is then immediately transferred to the pre-forging cavity of the die for pre-forging (the temperature after pre-forging is measured to be around 472℃ using a contact thermometer). The pre-forged billet is then immediately transferred to the final forging cavity of the die for final forging (the temperature after final forging is measured to be around 468℃ using a contact thermometer). Before forging, the die is ground to a roughness Ra of 0.4μm and preheated to 200℃. Before each forging step, a release agent is evenly sprayed onto the die. After final forging, the edges are trimmed, and the forging is then water-cooled. S4. Solution treatment: The forged aluminum alloy material is solution treated at 540℃ for 120 minutes. S5. Quenching: Immediately immerse the solution-treated aluminum alloy material in water for quenching. The quenching time is 10 minutes and the water temperature is 25°C. S6. Aging treatment: The quenched aluminum alloy material is held at 190℃ for 2 hours to obtain 6082 aluminum alloy forgings.

[0041] The forging structure design in this embodiment is as follows: Figure 1 As shown, the metal streamlines are parallel to the main load and the welding bevel direction. The parting surface is 20mm and 34mm away from the weld, respectively. Bevels are prohibited in the abrupt change zone of the cross section. A machining allowance of 4-7mm is left at the welding position. The thickness of the forging is 114mm.

[0042] The microstructure and properties of the obtained 6082 aluminum alloy forgings were tested. The grain size of the weld zone was 47 μm, the size of the second phase was ≤4 μm, and a large amount of residual tensile stress on the surface was released.

[0043] Welding tests were performed on the 6082 aluminum alloy forgings obtained in Example 1. Figure 2 The image shows the weld HAZ metallographic image of the 6082 aluminum alloy forging obtained in Example 1. Test results indicate that the 6082 aluminum alloy forging prepared according to this invention exhibits excellent resistance to weld cracking, such as... Figure 2 As shown, after the 6082 aluminum alloy forgings obtained in Example 1 were welded according to the AMS 2680 standard, no micro-cracks were found in the HAZ (metallographic analysis showed that the crack length per unit area was <0.1 mm / mm²).

[0044] Example 2 A method for preparing a 6082 aluminum alloy forging resistant to welding cracks includes the following steps: S1. An aluminum alloy ingot is obtained by smelting and casting according to the alloy ratio. The components of the aluminum alloy ingot, by mass percentage, include: Si 0.803%, Fe 0.215%, Cu 0.05%, Mn 0.628%, Mg 0.96% (Mg / Si=1.2), Cr 0.168%, Zn 0.013%, Ti 0.03%, with the balance being Al. S2. Ingot annealing and homogenization treatment: The aluminum alloy ingot obtained in step S1 is kept at 540℃ for 6 hours; after homogenization treatment, the ingot is extruded into bars, and the average grain size of the bars is measured to be 33μm. S3. Forging: The bar stock is placed in the pre-forging heating furnace and held at 510℃ for 4 hours. Then, it is immediately transferred to the upsetting cavity of the die for upsetting (the temperature after upsetting is measured to be around 490℃ using a contact thermometer). The upset billet is then immediately transferred to the pre-forging cavity of the die for pre-forging (the temperature after pre-forging is measured to be around 471℃ using a contact thermometer). The pre-forged billet is then immediately transferred to the final forging cavity of the die for final forging (the temperature after final forging is measured to be around 467℃ using a contact thermometer). Before forging, the die is ground to a roughness Ra of 1.6μm and preheated to 200℃. Before each forging step, a release agent is evenly sprayed onto the die. After final forging, the edges are trimmed, and the forging is then water-cooled. S4. Solution treatment: The forged aluminum alloy material is solution treated at 540℃ for 120 minutes. S5. Quenching: Immediately immerse the solution-treated aluminum alloy material in water for quenching. The quenching time is 10 minutes and the water temperature is 25°C. S6. Aging treatment: The quenched aluminum alloy material is held at 190℃ for 2 hours to obtain 6082 aluminum alloy forgings.

[0045] The forging structure design in this embodiment is consistent with that in Embodiment 1.

[0046] The microstructure and properties of the obtained 6082 aluminum alloy forgings were tested. The grain size of the weld zone was 52 μm, the size of the second phase was ≤4 μm, and a large amount of residual tensile stress on the surface was released.

[0047] Welding tests were performed on the 6082 aluminum alloy forgings obtained in Example 2. Figure 3 The image shows the weld HAZ metallographic image of the 6082 aluminum alloy forging obtained in Example 2. Figure 3 As shown, after the 6082 aluminum alloy forgings obtained in Example 2 were welded according to the AMS 2680 standard, no micro-cracks were found in the HAZ (metallographic examination showed that the crack length per unit area was <0.1 mm / mm²).

[0048] Comparative Example 1 The preparation method of 6082 aluminum alloy forgings includes the following steps: S1. An aluminum alloy ingot is obtained by smelting and casting according to the alloy ratio. The components of the aluminum alloy ingot, by mass percentage, include: Si 0.803%, Fe 0.215%, Cu 0.05%, Mn 0.628%, Mg 0.96% (Mg / Si=1.2), Cr 0.168%, Zn 0.013%, Ti 0.03%, with the balance being Al. S2. Ingot annealing and homogenization treatment: The aluminum alloy ingot obtained in step S1 is kept at 540℃ for 6 hours; after homogenization treatment, the ingot is extruded into bars, and the average grain size of the bars is measured to be 33μm. S3. Forging: The bar stock is placed in the pre-forging heating furnace and held at 530℃ for 2 hours. Then it is immediately transferred to the upsetting cavity of the die for upsetting. The upset billet is immediately transferred to the pre-forging cavity of the die for pre-forging. The pre-forged billet is immediately transferred to the final forging cavity of the die for final forging. Before forging, the die is ground to a roughness Ra of 3.2μm. The die is preheated to 200℃. Before each forging step, the die is evenly sprayed with a release agent. After forging, the edges are trimmed and the forging is air-cooled. S4. Solution treatment: The forged aluminum alloy material is solution treated at 540℃ for 150 minutes. S5. Quenching: Immerse the solution-treated aluminum alloy material in water for quenching. The quenching time is 10 minutes and the water temperature is 25℃. S6. Aging treatment: The quenched aluminum alloy material is held at 180℃ for 240 minutes to obtain 6082 aluminum alloy forgings.

[0049] The structural design of the forging in this comparative example is consistent with that in Example 1.

[0050] The microstructure and properties of the obtained 6082 aluminum alloy forgings were tested. The maximum grain size in the weld zone exceeded 2000 μm, and the size of the second phase was ≤4 μm.

[0051] Welding tests were conducted on the 6082 aluminum alloy forgings obtained in Comparative Example 1. Figure 4 The image shows the weld HAZ metallographic image of the 6082 aluminum alloy forging obtained in Comparative Example 1. Figure 4 As shown in Comparative Example 1, the forging produced using the traditional process exhibits several microscopic cracks in its microstructure after welding. This is because the pre-forging heating temperature is too high, causing grain growth and coarsening during the heating and holding process. Simultaneously, the roughness of the mold cavity surface increases the resistance to metal flow, leading to increased frictional heat after forging and affecting the near-surface temperature rise. During deformation, the metal grain boundaries break down and recrystallize. The near-surface recrystallized grains grow abnormally due to the excessively high temperature, further coarsening them. During subsequent heating, these grains engulf surface grains, forming coarse grain rings, resulting in weakened grain boundaries and the segregation of low-melting-point intermediates at the grain boundaries, leading to cracks during welding. After forging, the edge trimming and air cooling cause grain growth and alloy element segregation during slow cooling, also contributing to welding cracks. Longer solution treatment times and lower temperatures during aging further exacerbate grain growth and alloy element segregation.

[0052] Comparative Example 2 The difference between this comparative example and Example 1 is that in step S3, the bar stock is placed in a pre-forging heating furnace and held at 530°C for 2 hours. Other steps and parameters are the same as in Example 1.

[0053] Welding tests on the forgings revealed several short cracks in their microstructure. This was because the pre-forging heating temperature was too high, and the grains grew and coarsened during the heating and holding process, resulting in cracks.

[0054] Comparative Example 3 The difference between this comparative example and Example 1 is that in step S3, the surface roughness Ra of the pre-forging die and the final forging die is 3.2 μm.

[0055] After welding tests were conducted on the obtained forgings, several short cracks were found in their microstructure. This was because the surface roughness of the mold cavity was large, resulting in high frictional heat, which caused the surface grains of the forgings to overheat and coarsen, forming coarse grain rings. This led to weakening of grain boundaries, segregation of low-melting-point phases, and ultimately, cracks in the weld.

[0056] Comparative Example 4 The difference between this comparative example and comparative example 2 is that the aging treatment in step S6 involves holding the quenched aluminum alloy material at 180℃ for 4 hours.

[0057] Welding tests on the obtained forgings revealed several long cracks in their microstructure. Lower aging temperatures and longer aging times promote grain growth and more severe segregation of alloying elements, resulting in longer cracks.

[0058] Mechanical properties were tested on the 6082 aluminum alloy forgings obtained in Examples 1, 2 and Comparative Example 1. The tensile test method was performed according to GB / T 228.1, and the hardness test method was performed according to GB / T 231.1. The test results are shown in Table 1 below.

[0059] Table 1

[0060] The results in Table 1 show that the 6082 aluminum alloy forgings prepared by the present invention have good mechanical properties, which are improved to a certain extent compared with the aluminum alloy forgings prepared by the conventional forging process in Comparative Example 1.

[0061] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for preparing a 6082 aluminum alloy forging resistant to welding cracks, characterized in that, Includes the following steps: S1. Pretreatment: After annealing and homogenizing the aluminum alloy ingot, it is extruded to obtain aluminum alloy bar stock. S2. Forging: The aluminum alloy bar is preheated at 500~520℃ and then immediately upset to obtain a billet; the billet is immediately transferred to a pre-forging die for pre-forging, and then immediately transferred to a final forging die for final forging. After final forging, the edges are trimmed and water-cooled to obtain a die forging; wherein, the final forging temperature is controlled to be ≥420℃, and the roughness Ra of the pre-forging die and the final forging die is 0.4~1.6μm. S3. Heat treatment: The forging is subjected to solution treatment and aging treatment to obtain the 6082 aluminum alloy forging resistant to welding cracks.

2. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The aluminum alloy ingot comprises the following components by weight percentage: Si 0.7%~1.1%, Mg 0.6%~1.2%, Mn 0.5%~0.8%, Fe 0.1%~0.3%, Cr 0.1%~0.25%, Cu≤0.1%, Zn≤0.2%, Ti≤0.1%, and the balance Al.

3. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 2, characterized in that, The Mg to Si ratio in the aluminum alloy ingot composition is 1.0 to 1.

3.

4. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The annealing homogenization treatment specifically involves holding the aluminum alloy ingot at 530~550℃ for 4~12 hours.

5. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The pre-forging heating time shall not exceed 6 hours.

6. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The pre-forging die and final forging die need to be preheated to 180~220℃ before use and uniformly sprayed with a release agent.

7. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The streamline direction of the forging is parallel to the main load direction and the bevel direction; the distance between the parting surface of the forging and the weld is ≥10mm.

8. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The solution treatment specifically involves: holding the forging at 535~550℃ for a certain time T, followed by water quenching; The time T is: for every 20 mm thickness of the die forging, it needs to be kept at the solution temperature for 15 to 25 minutes, plus an additional safety margin of 10 to 15 minutes.

9. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 8, characterized in that, The water quenching time is 10-12 minutes, and the water temperature is 15-45℃.

10. The method for preparing a 6082 aluminum alloy forging resistant to welding cracks according to claim 1, characterized in that, The aging process specifically involves heat treatment at 190℃ for 2 hours.

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