A method for manufacturing a 7050 aluminum alloy die forging wheel hub

Abstract

The application relates to a manufacturing method of a 7050 hub aluminum alloy die forging piece, and relates to a manufacturing method of an aluminum alloy die forging piece. The application aims to solve the problem that the existing aluminum alloy plate is difficult to have high strength and high toughness, and the method comprises the following steps: S1, preparing an aluminum alloy ingot; S2, free forging; S3, die pressing; S4, machining; S5, heat treatment; and S6, flaw detection. The aluminum alloy hub die forging piece manufactured by the application not only meets the standard requirements, but also improves the overall use performance of the hub, improves the strength, wear resistance and other characteristics of the hub, prolongs the service life of the hub, and meets the requirements of high-performance aluminum alloy hub die forging pieces. The application is applied to the technical field of aluminum alloys.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a 7050 wheel hub aluminum alloy forging. Background Technology

[0002] With the development of modern industry, the performance requirements for vehicles are becoming increasingly stringent. As a crucial load-bearing component, the wheel hub operates under conditions of high friction, high intensity, and high load, making its quality paramount to vehicle safety. Currently, most wheel hubs use 2-series aluminum alloys such as 2A50. This alloy is a medium-strength aluminum alloy with good plasticity but relatively low strength, making it difficult to meet the requirements of heavy-duty vehicles. Wheel hubs manufactured using 7050 alloy forgings feature high structural strength, meeting the new needs of vehicle development and extending the service life of the wheel hub. This technology has broad application value in the automotive industry, playing a vital role in improving vehicle lightweighting and offering significant economic benefits. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of low strength and poor fracture toughness of existing wheel hubs, which cannot meet the development requirements, and to provide a method for manufacturing aluminum alloy forgings.

[0004] This invention discloses a method for manufacturing a 7050 wheel hub aluminum alloy forging, which is carried out according to the following steps:

[0005] I. Aluminum alloy ingots are prepared according to the following mass percentage composition of elements in the aluminum alloy ingots: Si ≤0.12%, Fe ≤0.15%, Cu 2.0%–2.6%, Mn ≤0.10%, Mg 1.9%–2.6%, Cr ≤0.04%, Zn 5.7%–6.7%, Ti ≤0.06%, Zr 0.08%–0.15%, single impurities ≤0.05%, total impurities ≤0.15%, and the remainder being Al. The ingots are heated to 380℃–430℃ and held for 4–6 hours to obtain a blank.

[0006] 2. After heating the blank obtained in step one, perform the first free forging, then saw it and heat it again for the second free forging to obtain the forging;

[0007] 3. The forgings obtained in step 2 are subjected to three lubrication molding processes at an initial forging temperature of 390℃~460℃ and a die temperature of 400℃~420℃, and then cleaned.

[0008] Fourth, use a boring machine to drill a center hole in the forging obtained in step four;

[0009] Fifth, the forgings obtained in step four are quenched and aged to complete a method for manufacturing aluminum alloy die forgings.

[0010] The beneficial effects of this invention are as follows: The 7050 aluminum alloy wheel hub forging manufactured by this invention uses 7050 aluminum alloy instead of 2A50 in the production of wheel hub forgings. This not only meets the standard requirements, but also significantly improves the strength. The tensile strength can be increased by 20%, the yield strength can be increased by 50%, and the elongation can meet the standard requirements. This improves the overall performance of the wheel hub, enhances its strength, and extends its service life, thus meeting the requirements for high-performance 7050 aluminum alloy wheel hub forgings. Attached Figure Description

[0011] Figure 1 Here is a 3D drawing A of the 7050 aluminum alloy wheel hub forging of this application;

[0012] Figure 2 This is a 3D drawing (B) of the 7050 aluminum alloy wheel hub forging in this application. Detailed Implementation

[0013] 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.

[0014] Specific Implementation Method 1: This implementation method describes a manufacturing method for a 7050 wheel hub aluminum alloy forging, which is carried out according to the following steps:

[0015] I. Aluminum alloy ingots are prepared according to the following mass percentage composition of elements in the aluminum alloy ingots: Si ≤0.12%, Fe ≤0.15%, Cu 2.0%–2.6%, Mn ≤0.10%, Mg 1.9%–2.6%, Cr ≤0.04%, Zn 5.7%–6.7%, Ti ≤0.06%, Zr 0.08%–0.15%, single impurities ≤0.05%, total impurities ≤0.15%, and the remainder being Al. The ingots are heated to 380℃–430℃ and held for 4–6 hours to obtain a blank.

[0016] 2. After heating the blank obtained in step one, perform the first free forging, then saw it and heat it again for the second free forging to obtain the forging;

[0017] 3. The forgings obtained in step 2 are subjected to three lubrication molding processes at an initial forging temperature of 390℃~460℃ and a die temperature of 400℃~420℃, and then cleaned.

[0018] Fourth, use a boring machine to drill a center hole in the forging obtained in step four;

[0019] Fifth, the forgings obtained in step four are quenched and aged to complete a method for manufacturing aluminum alloy die forgings.

[0020] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: in step two, the billet heating temperature is 380℃~420℃, and it is held at that temperature for 4~5 hours. During the first free forging, the anvil temperature is 350℃~400℃, and the billet is forged into a die billet according to the forging process. Everything else is the same as in Specific Implementation Method One.

[0021] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the forging process is: upsetting → single drawing → single multi-square forging → double drawing → double multi-square forging → triple drawing. Everything else is the same as in Specific Implementation Method One or Two.

[0022] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: after the first free forging in step two, the blank is first sawed and then heated to a temperature of 380℃~420℃ and held for 4~5 hours. During the second free forging, the anvil temperature is required to be 350℃~400℃, and the blank is forged according to the forging process. Everything else is the same as in Specific Implementation Methods One to Three.

[0023] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the forging process in Specific Implementation Method Five is: upsetting → single drawing → single multi-square forging → double drawing → double multi-square forging. Everything else is the same as in Specific Implementation Methods One to Four.

[0024] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that a 5000-ton hydraulic press is used for molding in step three. Everything else is the same as in Specific Implementation Methods One to Five.

[0025] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the cleaning described in step three is as follows: The forging to be cleaned is placed upright in a stainless steel etching basket and etched and degreased in an alkaline bath of 15% to 20 wt% NaOH at 50℃ to 70℃ for 10 to 20 minutes. Then, it is washed off the alkaline solution in a cold water bath at room temperature, followed by neutralization and whitening in an acid bath of 30% to 40 wt% HNO3 at room temperature for 5 to 8 minutes. The acid solution is then washed off in a cold water bath at room temperature, and finally, it is rinsed in a hot water bath at 50 to 70℃ to complete the process. All other steps are the same as in Specific Implementation Methods One to Six.

[0026] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the quenching temperature of the forging in step five is 460℃~475℃, and the holding time begins after the metal temperature reaches the quenching temperature, lasting for 90~150 minutes. Everything else is the same as in Specific Implementation Methods One to Seven.

[0027] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One through Eight in that: the temperature of the water used for quenching is 30℃~50℃; the quenching transfer time is ≤15 seconds; and the quenching basket is raised and lowered 15 times in the water, then left in the water for 15 minutes before being lifted out of the water. Everything else is the same as in Specific Implementation Methods One through Eight.

[0028] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One through Nine in that the single-stage aging temperature is 135℃~145℃, and the metal is held at that temperature for 16 hours after reaching the aging temperature. Everything else is the same as in Specific Implementation Methods One through Nine.

[0029] The beneficial effects of the present invention are verified using the following embodiments:

[0030] Example 1

[0031] A method for manufacturing an aluminum alloy forging, specifically comprising the following steps:

[0032] I. Aluminum alloy ingots are prepared according to the following mass percentage composition of elements in the aluminum alloy ingot: Si ≤0.12%, Fe ≤0.15%, Cu 2.0%–2.6%, Mn ≤0.10%, Mg 1.9%–2.6%, Cr ≤0.04%, Zn 5.7%–6.7%, Ti ≤0.06%, Zr 0.08%–0.15%, single impurities ≤0.05%, total impurities ≤0.15%, and the remainder being Al. The heating temperature of the ingot is controlled at 380℃–430℃, and the holding time is 4–6 hours. The prepared aluminum alloy ingot is a square shape with dimensions of 420×900×900mm, which is the blank.

[0033] II. Free forging of blanks required for forging: The blank heating temperature is 380℃~420℃ and held for 4~5 hours. The anvil temperature during free forging is required to be 350℃~400℃. The blank is forged according to the six-stage forging process (i.e., upsetting → first drawing → first multi-square forging → second drawing → second multi-square forging → third drawing).

[0034] 3. Second free forging of blanks required for forging: After forging, the blanks are first sawed, and then the blanks are heated to 380℃~420℃ and held for 4~5 hours. The anvil temperature during free forging is required to be 350℃~400℃. The blanks are forged according to the five-stage forging process (i.e., upsetting → first drawing → first multi-square forging → second drawing → second multi-square forging).

[0035] Fourth, the forgings obtained in step two are molded using a 5000-ton hydraulic press at an initial forging temperature of 390℃~460℃ and a mold temperature of 400℃~420℃, and the molding is lubricated three times.

[0036] 5. Place the forgings obtained in step 3 upright in a stainless steel etching basket and etch and degrease them in an alkaline bath of 15%–20wt% NaOH at 50℃–70℃ for 10–20 minutes. Then, wash off the alkaline solution in a cold water bath at room temperature, neutralize and wash them in an acid bath of 30–40wt% HNO3 at room temperature for 5–8 minutes, wash off the acid solution in a cold water bath at room temperature, and finally rinse the parts in a hot water bath at 50–70℃. After rinsing, place the parts on a repair area with aluminum pads on the ground for repair, and check and remove any defects in the forgings.

[0037] 6. Using a boring machine, center-drill the forgings obtained in step four.

[0038] 7. Heat treat the forgings obtained in step 5. The forgings should be placed upright in the quenching basket to facilitate water flow within the forging cavity. Sample materials should also be placed in the quenching basket simultaneously. The quenching temperature of the forgings is 460℃~475℃, and the holding time is 90~150 minutes for the metal. The temperature of the water used for quenching is 30℃~50℃. The quenching transfer time should be less than or equal to 15 seconds, and the quenching basket should be raised and lowered in the water 15 times, then left in the water for 15 minutes before being lifted out of the water. When marking the quenching furnace, the furnace number should be clearly marked and placed in the designated position. When loading the aging furnace, the rack should be positioned to ensure smooth air circulation for uniform and rapid heating. The temperature for single-stage aging is 135℃~145℃, with a holding time of 16 hours for the metal, and a total heating time of 16~20 hours.

[0039] 7. The forgings heat-treated in step 6 are subjected to 100% Class A flaw detection according to GJB1580A flaw detection standard, and then the finished products are packaged, thus completing a manufacturing method for aluminum alloy die forgings.

[0040] Table 1 Mechanical properties of 7050 alloy wheel forgings

[0041]

[0042] Table 2 Mechanical properties of 2A50 alloy wheel forgings

[0043]

[0044] Using 2A50 aluminum alloy wheel hub forgings as a control group, the mechanical properties of the aluminum alloy forgings prepared in this embodiment and the 2A50 aluminum alloy wheel hub forgings were tested. The results are shown in Tables 1 and 2. Replacing 2A50 with 7050 aluminum alloy in the production of wheel hub forgings not only meets the standard requirements but also significantly improves the strength. The tensile strength can be increased by 20%, the yield strength can be increased by 50%, and the elongation can meet the standard requirements. This improves the overall performance of the wheel hub, enhances its strength, and extends its service life, meeting the requirements for high-performance 7050 aluminum alloy wheel hub forgings.

Claims

1. A method for manufacturing a 7050 wheel hub aluminum alloy forging, characterized in that... This method is performed according to the following steps: I. Aluminum alloy ingots are prepared according to the following mass percentage composition of elements in the aluminum alloy ingots: Si ≤0.12%, Fe ≤0.15%, Cu 2.0%–2.6%, Mn ≤0.10%, Mg 1.9%–2.6%, Cr ≤0.04%, Zn 5.7%–6.7%, Ti ≤0.06%, Zr 0.08%–0.15%, single impurities ≤0.05%, total impurities ≤0.15%, and the remainder being Al. The ingots are heated to 380℃–430℃ and held for 4–6 hours to obtain a blank.

2. After heating the blank obtained in step one, perform a first free forging, then saw it and reheat it for a second free forging to obtain the forging. The blank heating temperature is 380℃~420℃ and held for 4~5 hours. During the first free forging, the anvil temperature is 350℃~400℃. The blank is forged into a die blank according to forging process six. Forging process six is ​​upsetting → first drawing → first multi-square forging → second drawing → second multi-square forging → third drawing. After the first free forging, the blank is sawn and then heated to 380℃~420℃ and held for 4~5 hours. During the second free forging, the anvil temperature is required to be 350℃~400℃. The blank is forged according to forging process five. Forging process five is upsetting → first drawing → first multi-square forging → second drawing → second multi-square forging.

3. The forgings obtained in step 2 are subjected to three lubrication molding processes at an initial forging temperature of 390℃~460℃ and a die temperature of 400℃~420℃, and then cleaned. Fourth, use a boring machine to drill a center hole in the forging obtained in step four; Fifth, the forgings obtained in step four are quenched and aged to complete a method for manufacturing aluminum alloy die forgings.

2. The manufacturing method of a 7050 wheel hub aluminum alloy forging according to claim 1, characterized in that... In step three, a 5000-ton hydraulic press is used for molding.

3. The manufacturing method of a 7050 wheel hub aluminum alloy forging according to claim 1, characterized in that... The cleaning process described in step three is as follows: Place the forgings to be cleaned upright in a stainless steel etching basket, and etch and degrease them in an alkaline bath of 15%–20 wt% NaOH at 50℃–70℃ for 10–20 minutes. Then, wash off the alkaline solution in a cold water bath at room temperature, neutralize and whiten them in an acid bath of 30–40 wt% HNO3 at room temperature for 5–8 minutes, wash off the acid solution in a cold water bath at room temperature, and finally rinse them in a hot water bath at 50–70℃ to complete the cleaning process.

4. The manufacturing method of a 7050 wheel hub aluminum alloy forging according to claim 1, characterized in that... Step 5: The quenching temperature of the forging is 460℃~475℃. After the metal temperature reaches the quenching temperature, the holding time begins and is 90~150 minutes.

5. The manufacturing method of a 7050 wheel hub aluminum alloy forging according to claim 1, characterized in that... The temperature of the water used for quenching is 30℃~50℃; the quenching transfer time is ≤15 seconds, and the quenching basket is raised and lowered 15 times in the water, and then left in the water for 15 minutes before being lifted out of the water.

6. The manufacturing method of a 7050 wheel hub aluminum alloy forging according to claim 1, characterized in that... The temperature for single-stage aging is 135℃~145℃, and the metal is held at the aging temperature for 16 hours after reaching the aging temperature.

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