Aluminum alloy ingot and its forging process, wheel rim processing technology

Abstract

The invention discloses an aluminum alloy ingot and a forging process thereof, and a rim processing process, wherein the rim processing process comprises punching and expanding the aluminum alloy forging billet after final forging, and then performing solid solution treatment after punching and expanding; cold spinning the aluminum alloy forging billet after solid solution treatment to obtain a rim blank, and then performing low temperature aging treatment after cold spinning; and fine machining the rim blank after low temperature aging treatment to obtain a rim finished product. Beneficial effects: The aluminum alloy forged rim manufactured by the rim processing process of the invention has high strength and good fatigue performance, and the rim processing process simplifies the processing procedures, reduces material processing waste, and reduces the rim manufacturing cost.

Description

Technical Field

[0001] The invention relates to the field of wheel rim processing, in particular to an aluminum alloy casting blank and a forging process thereof, and a wheel rim processing process. Background Art

[0002] At present, the manufacturing method of aluminum alloy rims is to forge first, and then machine the forging blank according to the drawing line to obtain the finished rim. After forging, the grains of the blank have been broken, and the deformation energy storage of the rim is relatively high. Static recrystallization occurs in the rim during heat treatment, and the recrystallization fraction is above 90%. The entire rim is almost entirely recrystallized structure. Excessive recrystallization of the rim structure leads to low strength and poor fatigue performance. The difference between the tensile strength and yield strength of the rim is about 20%, the yield fatigue life is low, and the stiffness is poor. When the wheel is subjected to a large impact force during use, it is easy to deform and fall out of the mold. Especially under complex road conditions and high load conditions, crack sources are easily generated on the rim surface, leading to wheel failure.

[0003] In addition, there are residual forging defects on the surface of the forging blank after forging. After subsequent spinning, the surface defects are still inherited on the rim surface. Therefore, the rim must be turned to remove the defects on the rim surface. That is, the spun surface of the wheel rim must be turned to meet normal use. In this way, a large amount of material must be cut off the rim, the material utilization rate is low, and the material cost is increased. Summary of the invention

[0004] The main purpose of the invention is to provide an aluminum alloy ingot and its forging process, and a rim processing process, aiming to solve the problems of low strength, poor fatigue performance and high manufacturing cost of existing aluminum alloy forged rims.

[0005] To solve the above problems, the present invention proposes an aluminum alloy ingot, which is cast from the following components in mass fraction: Si: 0.6-0.9%, Mg: 0.7-1.2%, Cu: 0.25-0.40%, Mn: 0.08-0.12%, Cr: 0.2-0.25%, Ti: 0.020-0.030%, Zr: 0.003-0.006%, Fe: less than 0.2%, Na: less than 0.0005%, Ca: less than 0.0005%, Pb: less than 0.005%, and the rest is Al and unavoidable impurities.

[0006] In one embodiment, the mass fraction ratio of Mg to Si is 1.3-1.7.

[0007] In one embodiment, the sum of the mass fractions of Mn and Cr is 0.28-0.35%.

[0008] In one embodiment, the aluminum alloy ingot is subjected to homogenization heat treatment, and the steps of the homogenization heat treatment include:

[0009] First, heat the aluminum alloy ingot to 380°C and keep it warm for 4 hours;

[0010] Then, the aluminum alloy ingot is heated to 545°C and kept at this temperature for 2 hours;

[0011] Finally, the aluminum alloy ingot is heated to 570°C and kept warm for 8 hours.

[0012] In addition, the present invention also proposes a forging process for an aluminum alloy ingot, comprising:

[0013] Peeling the surface of the aluminum alloy ingot described in any one of the above items to remove surface defects;

[0014] Heat the aluminum alloy ingot after surface peeling to a temperature of 385-445°C and keep it warm for 2-3 hours;

[0015] Pre-forging the heated aluminum alloy ingot at a temperature of 400-420° C. and a pre-forging deformation of 20%-30%;

[0016] The aluminum alloy forging billet after pre-forging is subjected to final forging, the final forging temperature is 410-420°C, and the final forging deformation is 50%-60%;

[0017] The aluminum alloy forging billet after final forging is subjected to solution treatment, with a solution temperature of 540-545°C, a holding time of 2.5-3 hours, a quenching transfer time of less than 10S, and a temperature of the aluminum alloy forging billet after quenching being lower than 40°C.

[0018] In one embodiment, the forging process of the aluminum alloy ingot further comprises:

[0019] The aluminum alloy forging billet after solution treatment is subjected to low temperature aging treatment, with a heating temperature of 178-183°C, kept warm for 6-7 hours, and cooled naturally after being taken out of the furnace.

[0020] In addition, the present invention also proposes a rim processing process, comprising:

[0021] Processing an aluminum alloy forging billet according to the forging process of the aluminum alloy casting billet mentioned above;

[0022] Punching and expanding the aluminum alloy forging billet after final forging, and then performing solid solution treatment after punching and expanding;

[0023] The aluminum alloy forging blank after solid solution treatment is cold spun to obtain a rim blank, and then subjected to low temperature aging treatment after cold spinning;

[0024] The wheel rim blank after low temperature aging treatment is finely processed to obtain the wheel rim finished product.

[0025] In one embodiment, before cold spinning of the aluminum alloy forging blank after solution treatment, a spinning positioning surface is firstly processed on the aluminum alloy forging blank.

[0026] In one embodiment, the cold spinning is completed within ten minutes after the solution treatment.

[0027] In one embodiment, the deformation amount of the cold spun aluminum alloy forging billet is 40%-50%.

[0028] Beneficial effects: The aluminum alloy forged rim manufactured by the rim processing technology of the present invention has high strength and good fatigue performance. The rim processing technology simplifies the processing procedures, reduces material processing waste, and reduces the rim manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a metallographic structure diagram of the aluminum alloy ingot of the present invention;

[0031] Figure 2 The invention discloses a metallographic structure diagram of a rim obtained by using the rim processing technology of the invention;

[0032] Figure 3 The present invention discloses a streamline organization diagram of a rim manufactured by the rim processing technology of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] Embodiment 1:

[0038] The present invention provides an aluminum alloy ingot, which is cast from the following components by mass fraction: Si: 0.6-0.9%, Mg: 0.7-1.2%, Cu: 0.25-0.40%, Mn: 0.08-0.12%, Cr: 0.2-0.25%, Ti: 0.020-0.030%, Zr: 0.003-0.006%, Fe: less than 0.2%, Na: less than 0.0005%, Ca: less than 0.0005%, Pb: less than 0.005%, and the rest is A l and inevitable impurities. It can be seen from the above component composition distribution that the Cu content is relatively high. Such a design is helpful to enhance the strength of the aluminum alloy ingot; the addition of Mn and Cr can inhibit its recrystallization during the casting process, reduce the content of recrystallized structure in the aluminum alloy ingot, and help enhance the strength and fatigue properties of the aluminum alloy ingot. Preferably, the sum of the mass fractions of Mn and Cr is 0.28-0.35%. The aluminum alloy ingot designed in this way has high strength, good fatigue performance and moderate casting cost.

[0039] In this embodiment, the addition of Cr and Mn can inhibit the dynamic recrystallization during the subsequent processing and forging of the aluminum alloy ingot, reduce the content of recrystallized structure in the aluminum alloy forging, and help enhance the strength and fatigue properties of the aluminum alloy forging.

[0040] Preferably, in this embodiment, the mass fraction ratio of Mg to Si is 1.3-1.7. This design makes it easy for Mg2Si to fully dissolve, thereby improving the strength and fatigue properties of the aluminum alloy forging billet.

[0041] In this embodiment, the aluminum alloy ingot needs to undergo homogenization heat treatment, and the steps of the homogenization heat treatment include:

[0042] First, the aluminum alloy ingot is heated to 380℃ and kept warm for 4 hours; then the aluminum alloy ingot is heated to 545℃ and kept warm for 2 hours; finally, the aluminum alloy ingot is heated to 570℃ and kept warm for 8 hours. The homogenization heat treatment designed in this way can fully dissolve Mg2Si and the residual second term in the aluminum alloy ingot can be fully dissolved, thereby obtaining an aluminum alloy ingot with excellent metallographic structure, such as Figure 1 shown.

[0043] Embodiment 2:

[0044] The present invention provides a forging process for an aluminum alloy ingot, which is used to forge the aluminum alloy ingot of the first embodiment into a forged ingot. Specifically, the forging process for the aluminum alloy ingot includes:

[0045] S1. Peeling the surface of the aluminum alloy ingot of the first embodiment to remove surface defects. Since the aluminum alloy ingot is cast, defects are inevitable on the surface. If these defects are left to be removed after the subsequent forging ingot is processed into a finished forging, it may cause problems such as excessive material removal, low material utilization rate, and serious material processing waste. However, peeling the surface defects before forging can reduce the amount of material removal, improve material utilization rate, and reduce material processing waste. Moreover, after the subsequent forging ingot is processed into a finished forging, there is no need to further process and remove surface defects, which reduces the processing technology and reduces the manufacturing cost of forgings.

[0046] S2. The aluminum alloy ingot after surface peeling is heated to a temperature of 385-445°C, with a temperature control accuracy of ±5°C, and kept warm for 2-3 hours. The furnace-out temperature of the aluminum alloy ingot is 400-420°C. This design can provide suitable temperature conditions for subsequent pre-forging.

[0047] S3, pre-forging the heated aluminum alloy ingot, the pre-forging temperature is 400-420°C, the pre-forging deformation is 20%-30%, the aluminum alloy ingot is pre-forged at 400-420°C, and at the same time, the appropriate forging deformation is added, so that the casting structure can be better destroyed. In addition, since the pre-forging temperature of 400-420°C is relatively low, a part of the grains in the aluminum alloy ingot can be elongated and coarsened along the contour direction, and then the aluminum alloy forging ingot will not be recrystallized during the subsequent heat treatment process, and part of the forging recovery structure is retained. With this design, the content of recrystallized structure in the obtained aluminum alloy forging ingot is not high, and the aluminum alloy forging ingot has high strength and good fatigue performance;

[0048] S4, final forging the aluminum alloy forging billet after pre-forging, the final forging temperature is 410-420°C, the final forging deformation is 50%-60%, and the preheating temperature of the forging die is 450°C. In this design, the deformation energy storage of the forging billet can be improved with a higher deformation amount. The elongated grains in the pre-forging process undergo partial dynamic recrystallization under higher deformation energy storage, and combine with the coarsened grains in the pre-forging process to form a heterogeneous structure. The existence of the heterogeneous structure can not only ensure that the streamlines generated in the forging process are not destroyed, but also improve the yield strength and stiffness of the aluminum alloy forging billet, so that the aluminum alloy forging billet has excellent fatigue performance and mechanical strength, but also provide qualified aluminum alloy forging billet for subsequent solid solution strengthening treatment;

[0049] S5. The aluminum alloy forging blank after final forging is subjected to solution treatment at a solution temperature of 540-545°C and a holding time of 2.5-3 hours, so that the strengthening phase Mg2Si in its material composition can be fully dissolved back to improve the strength and fatigue properties of the aluminum alloy forging blank; the quenching transfer time is within 10S, and preferably, the shorter the quenching transfer time, the better, which is more conducive to improving the mechanical strength and fatigue properties of the aluminum alloy forging blank; the temperature of the aluminum alloy forging blank after quenching is lower than 40°C. This design is convenient for providing suitable aluminum alloy forging blanks for subsequent mechanical processing.

[0050] In this embodiment, further, the forging process of the aluminum alloy ingot also includes:

[0051] S6. The aluminum alloy forging billet after the solid solution treatment is subjected to low-temperature aging treatment, with a heating temperature of 178-183°C and a heat preservation time of 6-7h. After being taken out of the furnace, it is naturally cooled. The low-temperature aging treatment process of the aluminum alloy forging billet after the solid solution treatment is a process of precipitation of the second phase from the supersaturated solid solution, which is also a kind of solid-state phase transformation. The transformation is completed by the nucleation and growth of the new phase, and the material strength is increased through precipitation strengthening, so that the hardness and strength of the material are increased. In addition, the aging time of 6-7h is relatively short and can meet the needs of industrial production.

[0052] The following describes a method for preparing a wheel rim using the forging process of the aluminum alloy ingot of Example 2.

[0053] Embodiment three:

[0054] The present invention provides a wheel rim processing technology, comprising:

[0055] S1. Peeling the surface of the aluminum alloy ingot of the aforementioned embodiment 1 to remove surface defects. Since the aluminum alloy ingot is cast, defects are inevitably present on the surface. If these defects are left to be removed after the subsequent forging ingot is processed into a finished forging, it will cause problems such as excessive material removal, low material utilization rate, and serious material processing waste. However, peeling the surface defects before forging can reduce the amount of material removal, improve material utilization rate, and reduce material processing waste. Moreover, after the subsequent forging ingot is processed into a finished forging, there is no need to further process and remove surface defects, which reduces the processing technology and reduces the manufacturing cost of forgings. Specifically for rim processing, the surface of the aluminum alloy ingot is peeled before forging. For example, removing 2mm on one side can completely remove the surface defects of the aluminum alloy ingot, while the surface area of ​​the rim blank after cold spinning is larger than that of the aluminum alloy ingot, and the amount of material that needs to be turned to remove the surface defects of the rim is also large, which is bound to cause a series of problems such as excessive material removal, low material utilization, serious material processing waste, and high rim manufacturing cost. After the surface defects are pre-positioned before forging and peeled, the turning amount is small, the material removal amount is reduced, the material utilization rate is improved, the material processing waste is reduced, and the rim manufacturing cost is reduced. In addition, the rim blank after subsequent cold spinning does not need to be further processed to remove surface defects, which reduces the processing technology and reduces the rim manufacturing cost.

[0056] In addition, the spinning surface of the rim blank after cold spinning has a hardened layer and streamlined structure. The hardened layer can improve the stiffness and strength of the rim, and the streamlined structure can improve the fatigue performance of the rim. If the surface defects are removed and placed after cold spinning, the hardened layer will be removed and the streamlined structure will be destroyed, resulting in a decrease in the stiffness, strength and fatigue performance of the rim.

[0057] In addition, removing surface defects after cold spinning increases the number of steps and the weight of the material, destroys the streamline of forging spinning, and reduces the fatigue life of the rim. On the other hand, the surface defects generated during the casting process of the aluminum alloy ingot can only be partially removed during the forging process, and the tiny residual defective tissue is not easy to be found on the surface of the finished product, resulting in a reduced fatigue life of the wheel rim and increased after-sales problems. Adding peeling before forging can remove the casting residue, reduce subsequent processing steps, retain the streamlined tissue of the rim, and provide qualified billets for subsequent forging and spinning rims.

[0058] S2. The aluminum alloy ingot after surface peeling is heated to a temperature of 385-445°C, with a temperature control accuracy of ±5°C, and kept warm for 2-3 hours. The furnace-out temperature of the aluminum alloy ingot is 400-420°C. This design can provide suitable temperature conditions for subsequent pre-forging.

[0059] S3, pre-forging the heated aluminum alloy ingot, the pre-forging temperature is 400-420°C, the pre-forging deformation is 20%-30%, the aluminum alloy ingot is pre-forged at 400-420°C, and at the same time, an appropriate forging deformation is added, which can better destroy its casting structure and make its casting structure fully deformed. In addition, due to the low pre-forging temperature of 400-420°C, a part of the grains in the aluminum alloy ingot can be elongated and coarsened along the contour direction, and then the aluminum alloy forging ingot will not be recrystallized during the subsequent heat treatment process, and a part of the forging recovery structure is retained. With this design, the content of recrystallized structure in the obtained aluminum alloy forging ingot is not high, and the aluminum alloy forging ingot has high strength and good fatigue performance;

[0060] S4. The aluminum alloy forging billet after pre-forging is subjected to final forging at a final forging temperature of 410-420°C, a final forging deformation of 50%-60%, and a preheating temperature of the forging die of 450°C. This design can improve the deformation energy storage of the forging billet with a higher deformation amount. The elongated grains in the pre-forging process undergo partial dynamic recrystallization under a higher deformation energy storage, and combine with the coarsened grains in the pre-forging process to form a heterogeneous structure. The existence of the heterogeneous structure can ensure that the streamlines generated in the forging process are not destroyed, such as Figure 3 As shown, the yield strength and stiffness of the aluminum alloy forging billet are improved, so that the aluminum alloy forging billet has excellent fatigue performance and mechanical strength, and can provide qualified aluminum alloy forging billet for subsequent solid solution strengthening treatment;

[0061] S5. Punching and expanding the aluminum alloy forging billet after final forging, for example, punching a hole with a diameter of φ90 mm on the aluminum alloy forging billet, removing the forging skin at the same time, and then expanding the hole, the expansion angle of which is 18-22°. This design can provide qualified spinning billet for subsequent cold spinning rims;

[0062] S6. The aluminum alloy forging blank after punching and expanding is subjected to solution treatment at a solution temperature of 540-545° C. and a holding time of 2.5-3 hours, so that the strengthening phase Mg2Si in the material composition is fully dissolved back to improve the strength and fatigue properties of the aluminum alloy forging blank; the quenching transfer time is within 10S, and preferably, the shorter the quenching transfer time, the better, which is more conducive to improving the mechanical strength and fatigue properties of the aluminum alloy forging blank; the temperature of the aluminum alloy forging blank after quenching is lower than 40° C. This design is convenient for providing suitable aluminum alloy forging blanks for subsequent mechanical processing;

[0063] S7. Process the spinning positioning surface on the aluminum alloy forging blank after solution treatment. Since the positioning accuracy of the forging process is not high, it is necessary to increase the lathe processing to make the wheel rim concentric before the next step of cold spinning. For example, the processing part is punching the hole diameter from φ90 to φ100mm, and the subsequent spinning uses the hole with a diameter of φ100 for positioning, so as to ensure the processing accuracy;

[0064] S8. Cold spinning is performed on the aluminum alloy forging blank with the spinning positioning surface processed, so that the aluminum alloy forging blank is finally formed along the inner contour of the mold and the spinning wheel trajectory, and a streamlined structure distributed along the contour line is obtained, the strength and fatigue life of the rim are improved, and finally a rim blank is obtained. The strength and fatigue performance of the aluminum alloy forging blank after forging + solid solution are high, so the obtained rim blank also has excellent mechanical strength and fatigue performance. The metallographic structure of the rim blank is as follows Figure 2 As shown;

[0065] In addition, cold spinning also increases the work hardening of the rim blank, further fiberizing the internal structure of the material, obtaining a fiber structure that conforms to the rim profile, and having no throughflow, eddy current and other phenomena in the spinning streamline, with a high fatigue life. At the same time, the hardened layer on the spinning surface is retained, increasing its stiffness and strength. In the prior art, the further turning process of the rim blank after spinning in order to remove surface defects will remove the hardened layer on the spinning surface, resulting in a decrease in the stiffness and strength of the rim.

[0066] In addition, before cold spinning, the spinning positioning surface is processed on the aluminum alloy forging blank after solid solution treatment to eliminate the high-temperature solid solution blank runout, so that the rim contour line meets the final product line under the forming of the spinning wheel of the CNC spinning machine, so that no further turning processing is required, and the hardened layer of the spinning processing is not damaged, which reduces the processing technology, saves the raw materials of the rim part, increases the material utilization rate, reduces the material processing waste, and helps to reduce the rim manufacturing cost;

[0067] S9. Perform low-temperature aging treatment on the cold-spun wheel rim blank, heating the blank to 178-183°C, keeping the temperature for 6-7h, and cooling it naturally after it is taken out of the furnace. The low-temperature aging treatment process of the wheel rim blank is a process of precipitation of the second phase from the supersaturated solid solution, which is also a kind of solid phase transformation. The transformation is completed by the nucleation and growth of the new phase, increasing the material strength for precipitation strengthening, and increasing the hardness and strength of the material. In addition, the aging time of 6-7h is relatively short, which can meet the needs of industrial production.

[0068] S10, finishing the rim blank after low temperature aging treatment to obtain a rim finished product, the finishing process comprising:

[0069] OP10: Turning upper wheel flange mounting plate;

[0070] OP20: Turning the lower mounting plate and turning the center hole;

[0071] OP30: Drilling bolt holes and air holes.

[0072] In this embodiment, during the cold spinning process, the rim runout of the spinning mold core is <0.1mm, and the selected wheel forming R angle is <the finished product R angle. This design ensures that the rim contour line meets the final product line under the forming of the spinning wheel of the CNC spinning machine. In this way, there is no need for subsequent turning processing, which reduces the processing technology, saves raw materials for the rim part, increases material utilization, reduces material processing waste, and helps to reduce the rim manufacturing cost.

[0073] In this embodiment, the cold spinning is completed within 10 minutes after the solution treatment. This design is because after more than 10 minutes, the strength of the hardened layer of the spinning process decreases by 3-8%, which is not conducive to obtaining a high-strength rim.

[0074] In this embodiment, the deformation of the cold spun aluminum alloy forging blank is 40%-50%. With this design, a high-strength rim can be obtained. Too low a deformation will lead to a decrease in the rim strength, and too high a deformation will easily crack the aluminum alloy forging blank and cause the product to be scrapped.

[0075] The performance of the aluminum alloy forged rim manufactured by the rim processing technology of the present invention is verified by two specific embodiments and one comparative example.

[0076] Embodiment 4:

[0077] The present embodiment provides an aluminum alloy forged rim, whose chemical composition, measured by mass percentage, includes: Si: 0.70%, Mg: 1.1%, Cu: 0.35%, Mn: 0.10%, Cr: 0.30%, Ti: 0.025%, Zr: 0.005%, Fe: 0.13%, and the rest is Al and unavoidable impurities.

[0078] The method for preparing the aluminum alloy forged rim of the present embodiment comprises the following steps:

[0079] (1) Aluminum alloy ingot sawing: Cut the long aluminum alloy ingot into short ingots with a diameter of 254 mm and a length of 234 mm after sawing;

[0080] (2) For billet peeling, the peeling machine removes 2mm on one side. Billet runout is less than 0.2mm;

[0081] (3) Billet heating: heating furnace temperature is 400°C, heating time is 3h;

[0082] (4) Pre-forging: the blank is pre-forged at a temperature of 410-420°C, the pre-forging deformation is reduced by 25%, the forging speed is 10-15 mm / sec, and the temperature of the forging after forging is 400-410°C;

[0083] (5) Final forging: forging is carried out at a forging deformation of 55% and a forging speed of 2 mm / sec. After the forging die is closed, the forging process is immediately returned and pressure holding is not allowed;

[0084] (6) Punching and reaming, the punching diameter is 90 mm and the reaming angle is 20°;

[0085] (7) High temperature solution treatment: using the residual heat of the blank after forging for solution treatment, heating temperature is 540°C, keeping temperature for 2.5h, quenching water transfer time is within 10S, and the temperature of the forging blank is below 40°C;

[0086] (8) Turn the spinning positioning surface, clamp the wheel rim ear of the forging blank, turn the center hole diameter of the forging blank to 100 mm, and turn the inner side of the rib of the forging blank to a diameter of 2 mm, with a cycle of one piece per 2 minutes;

[0087] (9) Spinning rim, spinning die runout 0.1mm, spinning wheel runout 0.05mm, spindle speed 500r / min, spinning wheel feed F350-500mm / s, spinning thinning rate 50%, fine spinning wheel forming R angle 8, rough spinning wheel forming R angle 15;

[0088] (10) Low temperature artificial aging, aging temperature 178 ° C, heat preservation for 7 hours, natural cooling after leaving the furnace;

[0089] (11) Machining, processing steps:

[0090] OP10: Turning upper wheel flange mounting plate;

[0091] OP20: Turning the lower mounting plate, turning the center hole:

[0092] OP30: Drilling bolt holes and air holes.

[0093] Embodiment five:

[0094] Except for the following parameters which are different from those in Example 4, the other contents are the same as those in Example 4;

[0095] The billet heating temperature is 380°C, the pre-forging deformation is 20%, and the final forging deformation is 60%.

[0096] Embodiment six:

[0097] Except for the following parameters which are different from those in Example 4, the other contents are the same as those in Example 4:

[0098] The solution temperature is 545°C and the aging temperature is 182°C.

[0099] Comparative Example:

[0100] This comparative example provides a 6061 aluminum alloy forged rim, the chemical composition of which is shown in the following table by mass percentage:

[0101]

[0102] The preparation method thereof comprises the following steps:

[0103] (1) Melt casting into round ingots: cast into ingots according to the composition in the above table, with a billet diameter of 254 mm and a length of 307 mm after sawing;

[0104] (2) Heating of cast ingot: heating furnace temperature is 470-480°C, heating time is 2h;

[0105] (3) Forging: The final wheel rim blank is forged multiple times. The process parameters are the same as the mainstream process parameters in the current industry. Therefore, the forging process belongs to the existing technology. The forging is lubricated with oil-based lubricant. The forging process temperature is between 430-460°C.

[0106] (5) Solution quenching: solution temperature is 530°C, time is 3h, quenching water transfer time is 15s, and the temperature of the forging billet after exiting the water is 35°C;

[0107] (6) Aging treatment: Aging treatment is carried out at 170°C for 8.5 hours, followed by air cooling after being taken out of the furnace;

[0108] (7) Machining, processing steps:

[0109] OP10: Rough turning of upper wheel rim mounting plate;

[0110] OP20: Rough wheel rim:

[0111] OP30: Machining bolt holes:

[0112] OP40: Finishing installation plate:

[0113] OP50 precision wheel rims.

[0114] Table 1. Performance test results of Examples 4-6 and Comparative Examples

[0115]

[0116] It can be seen from the above table that Examples 4-6 provided in the present application all have higher tensile strength, yield strength, fatigue performance and stiffness, and their performance is better than that of the control examples, because the internal structure of the aluminum alloy forged rim manufactured by the rim processing technology of the present invention is a fibrous tissue, and the streamlines are distributed according to the rim profile, the rim has high strength and good fatigue performance, and the rim does not require turning to remove surface defects. The rim processing technology simplifies the processing procedures, reduces material processing waste, and reduces the rim manufacturing cost.

[0117] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A rim processing technology, characterized in that: include: Peel off the surface of the aluminum alloy ingot to remove surface defects; Heat the aluminum alloy ingot after surface peeling to a temperature of 385-445°C and keep it warm for 2-3 hours; The heated aluminum alloy ingot is pre-forged at a temperature of 400-420°C and a pre-forging deformation of 20%-30%; The aluminum alloy forging billet after pre-forging is subjected to final forging, the final forging temperature is 410-420℃, and the final forging deformation is 50%-60%; Punching and expanding the aluminum alloy forging billet after final forging, and then performing solid solution treatment after punching and expanding; The aluminum alloy forging blank after solid solution treatment is cold spun to obtain a rim blank, and then subjected to low temperature aging treatment after cold spinning; The rim blank after low temperature aging treatment is fine-processed to obtain the rim finished product. The fine-processing process is as follows: OP10: Turning upper wheel flange mounting plate; OP20: Turning the lower mounting plate and turning the center hole; OP30: Drilling bolt holes and air holes; The aluminum alloy ingot is cast from the following components by mass fraction: Si: 0.6-0.9%, Mg: 0.7-1.2%, Cu: 0.25-0.40%, Mn: 0.08-0.12%, Cr: 0.2-0.25%, Ti: 0.020-0.030%, Zr: 0.003-0.006%, Fe: less than 0.2%, Na: less than 0.0005%, Ca: less than 0.0005%, Pb: less than 0.005%, and the rest is Al and unavoidable impurities, the mass fraction ratio of Mg to Si is 1.3-1.7, and the sum of the mass fractions of Mn and Cr is 0.28-0.35%. The aluminum alloy ingot is subjected to homogenization heat treatment, and the steps of the homogenization heat treatment include: First, heat the aluminum alloy ingot to 380°C and keep it warm for 4 hours; Then the aluminum alloy ingot was heated to 545°C and kept at this temperature for 2 hours; Finally, the aluminum alloy ingot was heated to 570°C and kept at this temperature for 8 hours; The temperature of the solution treatment is 540-545°C, the holding time is 2.5-3 hours, the quenching transfer time is within 10 seconds, and the temperature of the aluminum alloy forging billet after quenching is lower than 40°C; The low-temperature aging treatment is carried out at a heating temperature of 178-183° C., and is kept at this temperature for 6-7 hours, followed by natural cooling after being taken out of the furnace.

2. The rim processing process according to claim 1, characterized in that: Before cold spinning of the aluminum alloy forging billet after solid solution treatment, a spinning positioning surface is firstly processed on the aluminum alloy forging billet.

3. The rim processing process according to claim 1, characterized in that: The cold spinning is completed within ten minutes after the solution treatment.

4. The rim processing process according to claim 1, characterized in that: The deformation of cold-spinning aluminum alloy forging billet is 40%-50%.

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