Manufacturing method of large-size aluminum alloy special-shaped forged ring

Abstract

The invention discloses a manufacturing method of a large-specification aluminum alloy special-shaped forged ring, and belongs to the technical field of aluminum alloy machining. The invention aims to solve the problems of non-uniform production deformation, non-uniform alloy internal structure and performance, over-high cost, low single-piece yield and long production period in the production process of the existing special-shaped aluminum alloy forged ring. The method comprises the following steps: after charging and heating an aluminum alloy ingot, forging the aluminum alloy ingot into a blank according to a process of three-time upsetting and two-time drawing-out, punching, ring-forging and chambering, and machining an inner diameter and an outer diameter; and after heating, rolling forming is conducted on a special-shaped roller of a ring rolling mill, and inspection and flaw detection are conducted. The large-size aluminum alloy special-shaped forged ring manufactured through the method is stable and excellent in mechanical property; the tensile strength in the longitudinal direction, the transverse direction and the height direction is larger than or equal to 305 MPa, the yield strength in the longitudinal direction, the transverse direction and the height direction is larger than or equal to 127 MPa, and the ductility is larger than or equal to 14%. According to the large-specification aluminum alloy special-shaped forged ring manufactured through the method, data accumulation is provided for follow-up large-scale production, national defense and space flight and aviation career are better served, and national needs are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum alloy processing, and particularly relates to a manufacturing method of a large-specification aluminum alloy special-shaped forged ring. BACKGROUND

[0002] With the rapid development of aerospace and navigation industries, large ring forgings are widely used in the field of aerospace, and the key parts of important scientific research projects adopt aluminum alloy special-shaped forged rings. Conventional rectangular cross-section rings cannot meet the requirements, so the special-shaped ring formed in one piece has small machining allowance, high material utilization rate, and the metal flow lines of the ring are distributed along the special-shaped ring profile, which is beneficial to improving the corrosion resistance of the ring, and the performance and organization of the ring have greater advantages compared with the rectangular ring.

[0003] At present, large special-shaped rings are mostly machined after being rolled into rectangular rings. This method has large heat treatment thickness and the core of the ring is not directly stressed during rolling, which leads to poor mechanical property stability and cannot meet the requirements of high-performance aerospace rocket components such as fuel tanks and engine parts. Because a large amount of metal needs to be removed from the upper and lower surfaces after rolling, the single-piece yield rate is currently only 25.6%, and the production cycle is as long as one month. SUMMARY

[0004] The purpose of the application is to solve the problems of unstable alloy mechanical properties, high cost, low single-piece yield rate, and long production cycle in the production process of existing special-shaped aluminum alloy forged rings, and to provide a manufacturing method of a large-specification aluminum alloy special-shaped forged ring.

[0005] A manufacturing method of a large-specification aluminum alloy special-shaped forged ring, which is performed according to the following steps:

[0006] I. The aluminum alloy ingot meeting the requirements is heated and kept in the furnace, and then forged into a blank according to the process of three times of upsetting and two times of elongation. After the blank is reheated and returned to the furnace, punching and flattening are performed to obtain a forged ring. The forged ring is heated and then ring forging and hole expansion are performed. After the hole expansion, the two end faces of the forged ring are flattened, and then the inner and outer diameters are machined on a vertical lathe according to the process requirements;

[0007] II. The forged ring after the machining of the inner and outer diameters is heated and kept, and then special-shaped rolling is performed on a ring rolling mill to obtain a forged piece. Then performance and various organizations are checked, and after the inspection is qualified, each piece is 100% A-level flaw detection. After the flaw detection is qualified, a large-specification aluminum alloy special-shaped forged ring is obtained, and the manufacturing method is completed.

[0008] Further, the qualified aluminum alloy ingot in step one: the size of the aluminum alloy ingot is Φ482×1500mm cylindrical ingot; the mass percentage of the elements in the aluminum alloy ingot is Si≤0.30%, Fe≤0.35%, Cu≤0.10%, Mn 0.55%-0.70%, Mg 6.2%-6.7%, Zn≤0.15%, Ti 0.04%-0.08%, Be 0.0005%-0.005%, single impurity≤0.05%, total impurity≤0.15%, and the rest is Al; two-stage filtration and two-stage degassing are required during the aluminum alloy ingot casting process.

[0009] Further, the heating and heat preservation in step one: heating to 440-460℃ and heat preservation for 6-12h.

[0010] Further, the forging into a blank in step two in the manner of three times upsetting and twice elongating: forging on a 3000-ton vertical free forging machine, and controlling the flat anvil temperature during free forging to be 420-460℃.

[0011] Further, the heating and heat preservation in step two: heating to 420-450℃ and heat preservation for 8h; the reheat in step two: heat preservation at 440-460℃ for 4-6h.

[0012] Further, the punching in step two: sequentially punching at the center of the blank with a Φ450 hydraulic machine solid punch and a Φ450 hydraulic machine hollow punch.

[0013] Further, the ring forging and hole expanding after heating in step two: heating the ring to 420-440℃, and then using a free forging machine frame and a Φ380 mandrel to perform ring forging and hole expanding on a 3000-ton free forging hydraulic machine.

[0014] Further, the rolling in step three: using a ring rolling machine, the linear speed is 400-600mm / s, the core roller rolling amount is 0.5-1mm / s, and the height is not rolled.

[0015] Further, the performance and various organization checks in step three: detecting the longitudinal, transverse, and high tensile strength, yield strength, elongation, macrostructure flow lines, and fracture organization after the forging is cooled; the standard for the inspection in step three: the longitudinal, transverse, and high tensile strength is required to be≥305MPa, the longitudinal, transverse, and high yield strength is required to be≥127MPa, the elongation is required to be≥14%, the macrostructure deformation is uniform, and the fracture organization detection meets the process requirements.

[0016] Further, the 100% A-level flaw detection in step three: according to the flaw detection standard in GB / T6519 ultrasonic testing method for deformed aluminum alloy products.

[0017] The large-size aluminum alloy shaped forging ring manufactured by this invention not only meets the new aerospace application requirements, but also solves the problems of unstable alloy mechanical properties, high cost, low single-piece yield, and long production cycle in the production process of shaped aluminum alloy forging rings, reducing the metal input per ring. The large-size aluminum alloy shaped forging ring manufactured by this invention does not require machining of the bottom surface after rolling, achieving a single-piece yield of 45.7%, while shortening the production cycle to one week.

[0018] This invention relates to the preparation of a specialized irregular ring rolling die according to the client's process requirements. Using conventional methods, it is a roller-type die with upper and lower constraints, capable of constraining the deformation behavior of the billet in the height direction and improving the formability of the ring on the main roller. After adding a limiting step to the main roller of the irregular ring, deformation in the thickness direction and the height direction of the billet can be restricted, reducing the jamming phenomenon of the tapered roller and resulting in good irregular ring forming.

[0019] The large-size aluminum alloy shaped forging ring manufactured by this invention exhibits stable and excellent mechanical properties; its tensile strength in the longitudinal, transverse, and vertical directions is ≥305MPa, its yield strength in the longitudinal, transverse, and vertical directions is ≥127MPa, and its elongation is ≥14%. This large-size aluminum alloy shaped forging ring fills a technological gap, provides data accumulation for subsequent mass production, better serves the national defense and aerospace industries, and meets the needs of the country.

[0020] This invention is applicable to the manufacture of large-size aluminum alloy irregular forging rings. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the design and dimensions of the irregular ring rolling die in the embodiment;

[0022] Figure 2 The image shows a physical picture of a large-sized aluminum alloy irregular forging ring manufactured in the example.

[0023] Figure 3 This is a low-magnification microstructure diagram of the cross-section of a large-size aluminum alloy irregular forged ring manufactured in the example. Detailed Implementation

[0024] 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.

[0025] Specific Implementation Method 1: This implementation method discloses a manufacturing method for a large-size aluminum alloy irregular forged ring, which is carried out according to the following steps:

[0026] 1. The aluminum alloy ingots that meet the requirements are loaded into the furnace, heated and kept at the temperature. Then, they are forged into blanks according to the process of three upsetting and two drawing. After the blanks are heated in the furnace, they are punched and flattened to obtain forged rings. After the forged rings are heated, they are ring forging and hole expansion. After hole expansion, the two end faces of the forged rings are flattened. Then, the inner and outer diameters are machined on a vertical lathe according to the process requirements.

[0027] 2. After the inner and outer diameters are machined as described above, the forged ring is heated and kept at a certain temperature. Then it is rolled into shape on a ring rolling mill to obtain a forging. The performance and various microstructures are then checked. After passing the inspection, each piece is subjected to 100% Class A flaw detection. After passing the flaw detection, a large-size aluminum alloy shaped forged ring is obtained, thus completing the manufacturing method described above.

[0028] The process requirements described in this embodiment are the process standards signed by both parties.

[0029] In this embodiment, after passing the flaw detection, a large-size aluminum alloy irregular forged ring is obtained, which can then be packaged as a finished product.

[0030] In step two of this embodiment, before loading the furnace for heating, the surface of the aluminum alloy ingots that meet the requirements should be cleaned of dust, aluminum shavings, burrs and other debris. When loading the furnace, the aluminum alloy ingots should be placed neatly and stably on the material tray. During the heating process, the temperature should be measured every two hours and the results recorded.

[0031] In step two of this embodiment, the blank is forged by three upsetting and two drawing processes. The blank is required to be forged to the specified size required by the process, which is beneficial to the low magnification structure and properties of the forging. At the same time, during the forging process, attention should be paid to maintaining the anvil temperature at 420℃~460℃, in order to ensure the deformation quality and prevent forging cracks.

[0032] The leveling described in step two of this embodiment refers to leveling the blank after punching, in order to ensure that the overall size and shape of the blank are intact.

[0033] In step two of this embodiment, the machining of the inner and outer diameters must ensure the cleanliness of the forged ring surface and the uniformity of dimensions before rolling.

[0034] In step three of this embodiment, the special-shaped ring is formed by rolling on a ring mill using a special-shaped ring rolling die. The linear speed and the rolling amount of the mandrel are controlled to ensure the stability of the structure of the special-shaped forged ring. The special-shaped ring rolling die can be prepared by conventional methods according to the process requirements.

[0035] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the aluminum alloy ingots meeting the requirements in step one are cylindrical ingots with dimensions of Φ482×1500mm; the mass percentage of elements in the aluminum alloy ingots used are as follows: Si ≤0.30%, Fe ≤0.35%, Cu ≤0.10%, Mn 0.55%~0.70%, Mg 6.2%~6.7%, Zn ≤0.15%, Ti 0.04%~0.08%, Be 0.0005%~0.005%, individual impurities ≤0.05%, total impurities ≤0.15%, and the remainder being Al; the aluminum alloy ingot casting process requires double-stage filtration and double-stage degassing. Everything else is the same as in Specific Implementation Method One.

[0036] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the heating and holding process in step one involves heating to 440℃~460℃ and holding for 6~12 hours. Other steps and parameters are the same as in Specific Implementation Method One.

[0037] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that, in step two, the blank is forged using a three-stage upsetting and two-stage drawing process: forging is performed on a 3000-ton vertical free forging machine, and the anvil temperature is controlled at 420℃~460℃ during free forging. Other steps and parameters are the same as in Specific Implementation Method One.

[0038] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that, in step two, the heating and holding process involves heating to 420℃~450℃ and holding for 8 hours; the reheating process in step two involves holding at 440℃~460℃ for 4~6 hours. Other steps and parameters are the same as in Specific Implementation Method One.

[0039] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that, in step two, the punching is performed by sequentially using a solid punch and a hollow punch from a Φ450 hydraulic press to punch a hole in the center of the blank. Other steps and parameters are the same as in Specific Implementation Method One.

[0040] The purpose of the punching method in this embodiment is to ensure uniform metal flow during punching.

[0041] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that, in step two, ring forging and hole expansion are performed after heating: the forged ring is heated to 420℃~440℃, and then ring forging and hole expansion are performed on a 3000-ton free forging hydraulic press using a free forging machine frame and a Φ380 mandrel. Other steps and parameters are the same as in Specific Implementation Method One.

[0042] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that, in step three, the rolling process uses a ring mill with a linear speed of 400–600 mm / s, a mandrel rolling rate of 0.5–1 mm / s, and no height rolling is performed. Other steps and parameters are the same as in Specific Implementation Method One.

[0043] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that the performance and microstructure checks described in step three are as follows: After the forging cools, the longitudinal, transverse, and macroscopic tensile strength, yield strength, elongation, low-magnification microstructure streamlines, and fracture microstructure are tested. The passing standards for the checks in step three are: longitudinal, transverse, and macroscopic tensile strength ≥ 305 MPa; longitudinal, transverse, and macroscopic yield strength ≥ 127 MPa; elongation ≥ 14%; uniform low-magnification microstructure deformation; and fracture microstructure and other tests meeting the process requirements. Other steps and parameters are the same as in Specific Implementation Method One.

[0044] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that the 100% Class A flaw detection in step three is performed according to the flaw detection standards in GB / T6519 Ultrasonic Testing Methods for Wrought Aluminum Alloy Products. Other steps and parameters are the same as in Specific Implementation Method One.

[0045] The beneficial effects of the present invention are verified through the following embodiments:

[0046] Example:

[0047] A method for manufacturing large-size aluminum alloy irregular-shaped forged rings, comprising the following steps:

[0048] 1. The aluminum alloy ingots that meet the requirements are loaded into the furnace, heated and kept at the temperature. Then, they are forged into blanks according to the process of three upsetting and two drawing. After the blanks are heated in the furnace, they are punched and flattened to obtain forged rings. After the forged rings are heated, they are ring forging and hole expansion. After hole expansion, the two end faces of the forged rings are flattened. Then, the inner and outer diameters are machined on a vertical lathe according to the process requirements.

[0049] 2. After the inner and outer diameters are machined as described above, the forged ring is heated and kept at a certain temperature. Then it is rolled into shape on a ring rolling mill to obtain a forging. The performance and various microstructures are then checked. After passing the inspection, each piece is subjected to 100% Class A flaw detection. After passing the flaw detection, a large-size aluminum alloy shaped forged ring is obtained, thus completing the manufacturing method described above.

[0050] The aluminum alloy ingots that meet the requirements in step one of this embodiment are cylindrical ingots with dimensions of Φ482×1500mm; the mass percentage of elements in the aluminum alloy ingots are as follows: Si ≤0.30%, Fe ≤0.35%, Cu ≤0.10%, Mn 0.55%~0.70%, Mg 6.2%~6.7%, Zn ≤0.15%, Ti 0.04%~0.08%, Be 0.0005%~0.005%, individual impurities ≤0.05%, total impurities ≤0.15%, and the remainder is Al; the aluminum alloy ingots require double-stage filtration and double-stage degassing during the casting process.

[0051] In step one of this embodiment, the heating and heat preservation process involves heating to 450°C and maintaining the temperature for 8 hours.

[0052] In step two of this embodiment, the blank is forged by three upsetting and two drawing processes: forging is carried out on a 3000-ton vertical free forging machine, and the anvil temperature is controlled at 440°C during free forging.

[0053] In step two of this embodiment, the heating and holding process involves heating to 440°C and holding for 8 hours; the reheating process in step two involves holding at 450°C for 5 hours.

[0054] In step two of this embodiment, the punching is performed by sequentially punching the center of the blank with a solid punch and a hollow punch from a Φ450 hydraulic press.

[0055] In step two of this embodiment, the ring is heated and then expanded by ring forging: the ring is heated to 440°C, and then expanded by ring forging using a free forging machine frame and a Φ380 mandrel on a 3000-ton free forging hydraulic press.

[0056] The rolling process described in step three of this embodiment is as follows: a ring mill is used with a linear speed of 500 mm / s, a core roll rolling amount of 0.5 mm / s, and no height rolling is performed.

[0057] The performance and microstructure checks described in step three of this embodiment are as follows: After the forging is cooled, the longitudinal, transverse, and high-axis tensile strength, yield strength, elongation, low-magnification microstructure flow lines, and fracture microstructure are tested. The standards for passing the inspection in step three are: the longitudinal, transverse, and high-axis tensile strength ≥305MPa, the longitudinal, transverse, and high-axis yield strength ≥127MPa, the elongation ≥14%, the low-magnification microstructure deformation is uniform, and the fracture microstructure test meets the standards required by the process.

[0058] The 100% Class A flaw detection mentioned in step three of this embodiment is carried out in accordance with the flaw detection standards in the ultrasonic testing method for wrought aluminum alloy products in GB / T6519.

[0059] In step three of this embodiment, the shaped ring is formed by rolling on a ring mill using a special shaped ring rolling die. This can be prepared using conventional methods according to process requirements. The design and dimensions of the shaped ring rolling die are shown in the attached diagram. Figure 1 The mold material is 5CrNiMo, a type of roller mold with upper and lower constraints, which can constrain the deformation behavior of the billet in the height direction and improve the formability of the ring on the main roller. After adding the limiting step to the shaped main roller, the deformation in the thickness direction of the billet can be restricted, the deformation in the height direction can be restricted, the jamming phenomenon of the tapered roller is reduced, and the shaped ring is well formed.

[0060] The large-size aluminum alloy irregular forging ring manufactured in this embodiment is shown in the physical example. Figure 2 As shown.

[0061] Comparative example:

[0062] The differences from the embodiment are as follows: the heating and holding in step one are: heating to 430℃ and holding for 6 hours; the forging method is forging one, that is, only one upsetting is performed; after the ring forging hole expansion, no / no machining of the inner and outer diameter dimensions is performed; the linear speed during rolling is 200mm / s, the mandrel rolling amount is 0.3mm / s, and the size of the forging ring is checked at any time; the rest is the same as the embodiment.

[0063] The following four experiments were conducted according to the procedures of the examples and comparative examples, and the results of the ring rolling surface are shown in Table 1.

[0064] Table 1

[0065]

[0066] The large-size aluminum alloy irregular forging ring manufactured in this embodiment is shown in the physical example. Figure 2 As shown.

[0067] The low-magnification microstructure of the large-size aluminum alloy shaped forging ring manufactured in this embodiment is as follows: The large-size aluminum alloy shaped forging ring was destructively sampled and analyzed. Four groups of samples were taken along the circumferential direction for comparative analysis, and their low-magnification microstructure is as follows: Figure 3 As shown, the streamlines are distributed along the rolling deformation direction. The bottom of the irregular forged ring has a folding defect with a depth of about 5mm. Within the machining allowance, the machining requirements are met. The rolled forged ring can be machined to meet the user's needs.

[0068] The mechanical properties of the large-size aluminum alloy irregular forged ring manufactured in this embodiment are shown in Table 2.

[0069] Table 2

[0070]

[0071] The large-size aluminum alloy irregular forging ring manufactured in this embodiment was tested for triaxial tensile strength, low magnification microstructure, and hardness. The results met the requirements of triaxial tensile strength ≥305MPa, tensile strength ≥127MPa, and elongation ≥14%.

[0072] Each piece of the wrought aluminum alloy product undergoes 100% Class A flaw detection according to the GB / T6519 ultrasonic testing method for wrought aluminum alloy products. After passing the flaw detection, the irregular forged rings are packaged as finished products.

[0073] The above 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.

Claims

1. A method for manufacturing a large-size aluminum alloy irregular forged ring, characterized in that... It proceeds in the following steps:

1. The aluminum alloy ingots that meet the requirements are loaded into the furnace, heated and kept at the temperature. Then, they are forged into blanks according to the process of three upsetting and two drawing. After the blanks are heated in the furnace, they are punched and flattened to obtain forged rings. After the forged rings are heated, they are ring forging and hole expansion. After hole expansion, the two end faces of the forged rings are flattened. Then, the inner and outer diameters are machined on a vertical lathe according to the process requirements.

2. After the inner and outer diameters are machined as described above, the forged ring is heated and kept at a certain temperature. Then it is rolled into shape on a ring rolling mill to obtain a forging. The performance and various microstructures are then checked. After passing the inspection, each piece is subjected to 100% Class A flaw detection. After passing the flaw detection, a large-size aluminum alloy shaped forged ring is obtained, thus completing the manufacturing method described above.

2. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The aluminum alloy ingots that meet the requirements mentioned in Step 1 are cylindrical ingots with dimensions of Φ482×1500mm. The mass percentage of elements in the aluminum alloy ingots used is as follows: Si ≤0.30%, Fe ≤0.35%, Cu ≤0.10%, Mn 0.55%~0.70%, Mg 6.2%~6.7%, Zn ≤0.15%, Ti 0.04%~0.08%, Be 0.0005%~0.005%, with individual impurities ≤0.05% and total impurities ≤0.15%, the remainder being Al. The aluminum alloy ingots are required to undergo double-stage filtration and double-stage degassing during the casting process.

3. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The heating and holding process described in step one involves heating to 440℃~460℃ and holding for 6~12 hours.

4. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The blank is forged by three upsetting and two drawing processes as described in step two: it is forged on a 3000-ton vertical free forging machine, and the anvil temperature is controlled at 420℃~460℃ during free forging.

5. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The heating and holding process in step two involves heating to 420℃~450℃ and holding for 8 hours; the reheating process in step two involves holding at 440℃~460℃ for 4~6 hours.

6. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The punching described in step two involves punching holes in the center of the blank using a solid punch and a hollow punch from a Φ450 hydraulic press in sequence.

7. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... Step 2 involves ring forging and hole expansion after heating: the forged ring is heated to 420℃~440℃, and then ring forging and hole expansion is performed on a 3000-ton free forging hydraulic press using a free forging machine frame and a Φ380 mandrel.

8. The method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The rolling process described in step three involves using a ring mill with a linear speed of 400–600 mm / s, a core roll rolling amount of 0.5–1 mm / s, and no height rolling.

9. A method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The performance and microstructure checks described in Step 3: After the forging is cooled, the longitudinal, transverse, and high-axis tensile strength, yield strength, elongation, low-magnification microstructure flow lines, and fracture microstructure are tested. The standards for passing the tests described in Step 3 are: the longitudinal, transverse, and high-axis tensile strength ≥305MPa, the longitudinal, transverse, and high-axis yield strength ≥127MPa, the elongation ≥14%, the low-magnification microstructure deformation is uniform, and the fracture microstructure test meets the standards required by the process.

10. A method for manufacturing a large-size aluminum alloy irregular forged ring according to claim 1, characterized in that... The 100% Class A flaw detection mentioned in step three shall be carried out in accordance with the flaw detection standards in the ultrasonic testing method for wrought aluminum alloy products in GB / T6519.

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