Aluminum alloy super large ring piece collar ring rolling forming method

Abstract

The application belongs to the technical field of non-ferrous metal material preparation, and particularly relates to a kind of aluminum alloy super-large ring piece sleeve ring ring rolling forming method, comprising the following steps, 1) a plurality of initial ring pieces with different inner diameters and capable of being tightly sleeved together in sequence are prepared, and adjacent sleeved initial ring pieces can be interference fit;2) the surface of the initial ring piece is cleaned;3) by heating the initial ring piece with larger inner diameter, the initial ring piece is sleeved on the initial ring piece with smaller inner diameter, the plurality of initial ring pieces are tightly sleeved together to form an intermediate ring piece;4) the temperature of the outermost initial ring piece in the intermediate ring piece is controlled to be greater than 130 DEG C, the intermediate ring piece is expanded, the expansion rate is 8~9%, and the intermediate ring piece is cooled to room temperature to obtain a to-be-rolled ring piece;5) the to-be-rolled ring piece is heated to 400~450 DEG C and then rolled to obtain an aluminum alloy ring piece;The application can prepare super-large ring pieces, reduce defects of super-large ring pieces, and ensure uniform and consistent structure.

Description

Technical Field

[0001] This invention belongs to the field of non-ferrous metal material preparation technology, specifically relating to a method for rolling and forming ultra-large aluminum alloy ring components. Background Technology

[0002] With the continuous advancement of manufacturing, the demand for large forgings is increasing, especially in the aerospace industry. Integral forgings are constantly evolving towards larger sizes, such as rocket forgings, which have grown from 2.25 meters to 3.35 meters, and then to 5-meter diameter forgings. Future super-heavy rocket forgings may have diameters exceeding 15 meters, resulting in a significant increase in weight. Currently, the maximum weight of a single aluminum alloy ingot that can be forged is only about 10 tons. To forge a ring weighing over 15 tons, the ingot diameter would need to reach Φ1500mm. Obviously, casting a Φ1500 aluminum alloy ingot is impossible, so no aluminum alloy forging weighing 15 tons has yet been manufactured in the world.

[0003] Existing aluminum alloy forging technology is highly mature for producing aluminum alloy forged rings with a diameter of up to 5 meters and a weight of less than 5 tons. However, the production of aluminum alloy forged rings with a diameter of 10 meters and a weight of 10 tons is still in the research and trial production stage, with an extremely low yield. Currently, no technology can produce aluminum alloy forged rings with a diameter of 15 meters (weighing 15 tons) or even 20 meters (weighing 20 tons). How to produce forged rings with a larger diameter, greater weight, and meeting quality standards than current technology is a problem that technical personnel urgently need to solve.

[0004] The main aluminum alloy grades used in aerospace are 2XXX, 5XXX, and 7XXX series. Within the 2XXX series, only 2219 aluminum alloy can currently be produced into ingots with a diameter of up to Φ1300mm (less than Φ1250mm after machining), but the yield rate is low and the quality is inconsistent. Other commonly used aerospace alloys, such as 2A14, currently have a maximum ingot diameter of no more than Φ1000mm. Therefore, the largest malleable ingot size for 2XXX series aluminum alloys is currently Φ1250*Φ3800mm (13 tons). For 5XXX series, 7XXX series, aluminum-lithium alloys, and aluminum-based composite materials, such as 5A06, 7050, and 1420 aluminum alloys, the maximum diameter ingot currently produced is only Φ900mm, with a malleable ingot size of Φ860*Φ3000mm (5 tons). Existing ring rolling equipment has a rolling capacity of up to 16 meters. Even with ring rolling machines, the current technology cannot produce aluminum alloy forged rings weighing up to 15 tons due to ingot weight limitations.

[0005] Patent application number CN202111534804.6 discloses a hot rolling forming method for constructing large aluminum alloy rings. The method uses a hot rolling forming method for constructing rings, but it has the following drawbacks: the constructed surface is prone to cracking when rolling the ring after construction, small feed rate is required, small deformation is required for each rolling, and multiple production runs are required. This method is inefficient, the quality is difficult to guarantee, and it cannot achieve true industrial production.

[0006] Patent application number CN202310357075.4 discloses a method for stacking and rolling thin-walled rings, mainly targeting steel parts, such as high-temperature alloys. Due to the inherent properties of steel, if there are looseness, holes or small cracks in the center during forging or rolling, they can be healed through deformation. However, for aluminum alloys and magnesium alloys, due to their inherent physical properties (the crystal structure is face-centered cubic and the deformation process has poor fluidity), once there are looseness, holes or small cracks in the center of the forging or ring, they cannot be eliminated by forging or rolling deformation. Instead, they will become larger and larger until they completely crack. Therefore, this method is not suitable for aluminum alloys or magnesium alloys. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for forming ultra-large aluminum alloy rings by rolling, which can produce ultra-large rings, reduce defects in ultra-large rings, and ensure uniform and consistent microstructure.

[0008] This invention provides a method for forming ultra-large aluminum alloy ring sleeves by rolling, comprising the following steps: 1) Multiple initial rings with different inner diameters are prepared and can be tightly fitted together in sequence, with adjacent initial rings being able to be interference-fitted; 2) Clean the surface of the initial ring; 3) By heating the initial ring with a larger inner diameter and fitting it onto the initial ring with a smaller inner diameter, multiple initial rings are tightly fitted together to form an intermediate ring; 4) Control the temperature of the outermost initial ring of the intermediate ring to be greater than 130℃, expand the intermediate ring to a rate of 8-9%, cool it to room temperature, and obtain the ring to be rolled; 5) Heat the ring to be rolled to 400~450℃ and then roll it to obtain an aluminum alloy ring.

[0009] Preferably, multiple aluminum alloy rings with different inner diameters are prepared and can be tightly fitted together in sequence, and adjacent fitted aluminum alloy rings can be interference fit. Repeat steps 1)-5) above at least once to obtain an ultra-large aluminum alloy ring.

[0010] Preferably, in the initial rings of adjacent sets, the inner diameter of the initial ring with the larger inner diameter is 1-3 mm smaller than the outer diameter of the initial ring with the smaller inner diameter.

[0011] Preferably, the surface roughness of the initial ring is not greater than Ra1.6.

[0012] Preferably, the surface of the initial ring is cleaned by sequentially performing alkaline washing, water washing, acid washing, and hot water washing on the initial ring.

[0013] Preferably, the alkaline washing solution is a 5-15% sodium hydroxide solution at a temperature of 50-60°C; the acid washing solution is a 20-35% nitric acid solution; and the hot water is at a temperature of 60°C or higher.

[0014] Preferably, before heating the initial ring with a larger inner diameter, the initial ring with a larger inner diameter is completely wrapped with aluminum foil, and then heated.

[0015] Preferably, the heating temperature of the initial ring with a larger inner diameter is 150~200℃.

[0016] Preferably, the equipment used for ring rolling is a ring rolling mill, which only rolls the wall thickness and not the height direction.

[0017] Preferably, the feed rate during ring rolling is 1~3 mm / s.

[0018] The beneficial effect of this invention is that it combines two, three, or more small initial rings with machined surfaces using an interference fit, then performs bulging to bond the rings together, forming a complete ring. After heating, the ring is rolled on a ring rolling mill to increase its diameter. After rolling, the above steps can be repeated to connect multiple rings together again for rolling. The number of cycles required depends on the final ring size, ultimately producing a qualified integral ring.

[0019] This invention uses aluminum foil wrapping, bulging deformation, and cold shrinkage extrusion to ensure effective bonding at the intersection of rings, ensuring no air is left on the surface (or squeezing out any residual air), thus effectively guaranteeing uniform and consistent structure. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the two initial ring components assembled together in this invention.

[0021] Figure 2 This is a schematic diagram of the structure of the three initial ring components assembled together in this invention.

[0022] Figure 3 This is a schematic diagram of the structure of the three initial ring components of the present invention after being assembled together and expanded.

[0023] Figure 4 This is a physical image of the final aluminum alloy ring after rolling.

[0024] Figure 5 The final ultrasonic test results for the aluminum alloy ring are shown. Detailed Implementation

[0025] Example 1 A method for forming ultra-large aluminum alloy ring components by rolling includes the following steps. 1) Multiple initial rings with different inner diameters are prepared and can be tightly fitted together in sequence, with adjacent initial rings being able to be interference-fitted; The size of the initial ring is determined based on the size of the final aluminum alloy super-large ring. This embodiment 1 uses the final aluminum alloy super-large ring (outer diameter 16 meters, inner diameter 15.7 meters, height 0.8 meters, weight 17 tons) as an example for illustration.

[0026] The initial rings can be tightly fitted together in sequence. Therefore, the outer diameter of the first ring is approximately equal to the inner diameter of the second ring, and the inner diameter of the third ring is approximately equal to the outer diameter of the second ring. Before the final forming of the initial rings, the dimensions of the initial rings before forming are as follows: the dimensions of the first ring are Φ5010 (outer diameter) × Φ4790 (inner diameter) × Φ950 (height), the dimensions of the second ring are Φ5210 × Φ4990 × Φ950, and the dimensions of the third ring are Φ5410 × Φ5190 × Φ950, all in mm. Then, machining is performed to remove surface defects from the rings, ensuring a surface roughness no greater than Ra1.6. After machining, the ring dimensions must adhere to the following rule: the outer diameter of the first ring must be 1mm larger than the inner diameter of the second ring, and the outer diameter of the second ring must be 1mm larger than the inner diameter of the third ring. The dimensions of the first ring after machining are Φ5001×Φ4800×Φ902, the second ring is Φ5201×Φ5000×Φ902, and the third ring is Φ5400×Φ5200×Φ902 (units are mm). This arrangement ensures an interference fit between the initial rings of adjacent sets. After machining, ultrasonic testing is performed to ensure the rings are defect-free, thus guaranteeing that the final product meets requirements. For multiple rings, the dimensions follow the same principle.

[0027] 2) Clean the surface of the initial ring; The cleaning method involves sequentially performing alkaline washing, water washing, acid washing, and hot water washing on the initial ring. The alkaline washing uses a 5-15% sodium hydroxide solution at a temperature of 50-60°C for 10 minutes; the acid washing uses a 20-35% nitric acid solution for 3-5 minutes; and the hot water is heated to above 60°C.

[0028] 3) By heating the initial ring with a larger inner diameter and fitting it onto the initial ring with a smaller inner diameter, multiple initial rings are tightly fitted together to form an intermediate ring; When aluminum alloys are heated, they expand. Therefore, by heating the initial ring with the larger inner diameter, the inner diameter of the larger initial ring will increase. Once the inner diameter of the larger initial ring increases to more than 1 mm, it can accommodate the smaller initial ring, thus fitting the two initial rings together. After cooling, the two initial rings will form an interference fit. Generally, the heating temperature of the initial ring with the larger inner diameter is 150~200℃, and the ring diameter will deform by about 2% due to thermal expansion.

[0029] Before heating the initial ring with a larger inner diameter, completely wrap the initial ring with aluminum foil. After wrapping, heat it. The purpose of this operation is to prevent oxidation of the aluminum alloy surface during the heating process. The aluminum foil is wrapped in a spiral manner without leaving any gaps. After heating is completed, immediately remove it, tear off the aluminum foil, and then immediately put it together with the first initial ring.

[0030] By performing the above steps sequentially, three or more initial ring components can be assembled together. The three rings of the aforementioned dimensions, when assembled, deform into a single ring with dimensions of Φ5400mm × Φ4800mm × Φ902mm. The ring's wall thickness increases, and its weight increases approximately threefold, reaching 12.4 tons.

[0031] 4) Control the temperature of the outermost initial ring of the intermediate ring to be greater than 130℃, expand the intermediate ring to a rate of 8-9%, cool it to room temperature, and obtain the ring to be rolled; The temperature of the outermost initial ring is controlled to be above 130℃. This is achieved by immediately bulging the rings after they are all assembled, ensuring the temperature of the outermost initial ring exceeds 130℃. As the outermost initial ring cools to room temperature, it gradually shrinks by approximately 1% (for example, the dimensions of the three rings mentioned above, after bulging and cooling to room temperature, would be Φ5710mm × Φ5145mm × Φ900mm). This bulging + outer layer shrinkage method bonds all the rings together and squeezes out the air between them, preventing oxidation at the joints during the subsequent ring rolling heating process. This ensures the uniformity of the microstructure at the ring-to-ring junctions and the formation of a common interface (i.e., microstructure homogeneity) after rolling.

[0032] 5) Heat the ring to be rolled to 400~450℃ and then roll it to obtain an aluminum alloy ring.

[0033] The equipment used for ring rolling is a ring rolling mill. During ring rolling, only the wall thickness is rolled, not the height direction. The feed rate during ring rolling is 1~3mm / s. The larger the feed rate, the better. Roll the ring to the required size. If the weight or size is insufficient, roll the ring to the intermediate size with a deformation of 35%~50%, and then repeat the above steps. Roll one or more more rings, machine them, then fit them together, and then expand and roll the ring again. To ensure the final dimensions can be achieved (for example, a ring of the above dimensions can first be rolled to Φ10010×Φ9700×Φ900, with a ring deformation of 45%, then roll one Φ9710×Φ9590×Φ900 and one Φ10110×Φ10000×Φ900, followed by machining, surface treatment, and ring fitting. After ring fitting, the dimensions become Φ10100×Φ9600×Φ850, weighing 18.7 tons. After bulging and rolling, the final dimensions are Φ16010×Φ15700Φ×850, with a ring deformation of 38%. The final machined dimensions are an outer diameter of 16 meters, an inner diameter of 15.7 meters, a height of 0.8 meters, and a weight of 17 tons, in mm).

[0034] The quality of the final aluminum alloy ring is tested by ultrasonic testing. Class A ultrasonic testing according to GJB1580 standard can be performed to confirm whether there are any defects exceeding the standard. The actual product is as follows... Figure 4 As shown, the test results are as follows Figure 5 As shown, the test was passed.

[0035] This invention overcomes the limitations of raw material (ingot) size and quality, enabling the production of ultra-large ring components that can only be manufactured from large ingots. Multiple smaller, higher-quality ring components are used as initial blanks. Because ultrasonic testing is performed after machining, it ensures that the initial blanks are qualified products, preventing defects from being inherited into the final product, thus guaranteeing product quality and improving manufacturing yield.

[0036] This invention achieves defect-free collars by using aluminum foil wrapping, bulging deformation, and cold shrinkage extrusion to ensure effective bonding at the intersection of the rings, ensuring no air is left on the surface (or squeezing out any residual air), thus effectively guaranteeing uniform and consistent structure.

[0037] This invention can be used not only for aluminum alloys, aluminum-lithium alloys, and aluminum-based composite materials, but also for magnesium alloys, titanium alloys, and their metal-based composite materials. It can also be used for forming different materials to realize a new type of ring with three metal materials (such as magnesium alloy for the inner circle, aluminum alloy for the middle circle, and aluminum-based composite material for the outer circle) integrated into one piece, providing ideas for the research and development of subsequent functional materials.

[0038] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0039] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A method for forming ultra-large aluminum alloy ring components by rolling, characterized in that, Includes the following steps, 1) Multiple initial rings with different inner diameters are prepared and can be tightly fitted together in sequence, with adjacent initial rings being able to be interference-fitted; 2) Clean the surface of the initial ring; 3) By heating the initial ring with a larger inner diameter and fitting it onto the initial ring with a smaller inner diameter, multiple initial rings are tightly fitted together to form an intermediate ring; 4) Control the temperature of the outermost initial ring of the intermediate ring to be greater than 130℃, expand the intermediate ring to a rate of 8-9%, cool it to room temperature, and obtain the ring to be rolled; 5) Heat the ring to be rolled to 400~450℃ and then roll it to obtain an aluminum alloy ring; Before heating the initial ring with a larger inner diameter, completely wrap the initial ring with aluminum foil, and then heat it. Multiple aluminum alloy rings with different inner diameters that can be tightly fitted together in sequence are prepared, and adjacent fitted aluminum alloy rings can be interference-fitted. Repeat step 1 above) 5) Obtain an ultra-large aluminum alloy ring at least once.

2. The molding method as described in claim 1, characterized in that, In the initial rings of adjacent sets, the inner diameter of the initial ring with the larger inner diameter is 1-3 mm smaller than the outer diameter of the initial ring with the smaller inner diameter.

3. The molding method as described in claim 1, characterized in that, The surface roughness of the initial ring is no greater than Ra1.

6.

4. The molding method as described in claim 1, characterized in that, The surface of the initial ring is cleaned by sequentially performing alkaline washing, water washing, acid washing, and hot water washing.

5. The molding method as described in claim 4, characterized in that, The alkaline washing solution is a 5-15% sodium hydroxide solution at a temperature of 50-60°C; the acid washing solution is a 20-35% nitric acid solution. The temperature of the hot water is above 60°C.

6. The molding method as described in claim 1, characterized in that, The initial ring with a larger inner diameter is heated at 150~200℃.

7. The molding method as described in claim 1, characterized in that, The equipment used for ring rolling is a ring rolling mill. During ring rolling, only the wall thickness is rolled, not the height direction.

8. The molding method as described in claim 7, characterized in that, The feed rate during ring rolling is 1~3 mm / s.

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