Large centrifugal casting ring high performance radial forging and semi-solid ring rolling composite process

Abstract

A large centrifugal casting ring high-performance radial forging and semi-solid ring rolling composite process, first adopts centrifugal casting process to prepare large circular cross-section ring blank; then the three hammer head radial forging plastic deformation of large circular cross-section ring blank is carried out by using the centrifugal casting afterheat, and the large ring forging state ring is obtained; then the large ring forging state ring is remelted again to obtain the large ring semi-solid blank with fine, uniform and spherical microstructure; then the large ring semi-solid blank is formed into a large rectangular cross-section ring by semi-solid ring rolling; finally, the large rectangular cross-section ring is heat treated after ring rolling, and finally the large ring forming piece is prepared; the large ring with non-dendritic, fine and dense, uniform and spherical microstructure can be prepared, and the large ring has the advantages of high efficiency, high performance, low energy consumption and low cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of large ring manufacturing, and particularly relates to a large centrifugal casting ring high-performance radial forging and semi-solid ring rolling composite process. BACKGROUND

[0002] The demand for heavy-duty launch vehicles with greater delivery capacity is becoming more and more urgent for manned moon landing, space station construction and deep space exploration. Large rings, as key components of heavy-duty launch equipment, greatly affect the delivery capacity of heavy-duty launch equipment. Therefore, the development of high-performance large ring forming technology is crucial to the development of heavy-duty launch equipment. At the same time, with the continuous development and upgrading of the wind power industry, the demand for large rings for large bearing rings and large wind power gear rings in wind power equipment is increasing. Therefore, it is urgent to develop new efficient manufacturing processes for large rings.

[0003] The traditional manufacturing process of large rings (Determination method of blank size in ring casting-rolling composite forming process [J]) uses solid ingots as raw materials, cuts the riser, heats the whole, solid ingot forging, repeated upsetting and drawing, punching, core rod hole expansion, horse frame hole expansion, and ring rolling. The traditional manufacturing process using the above-mentioned solid ingot as raw material has the following disadvantages: (1) Large ingots have excess parts such as riser, flash and burr, which need to be removed by cutting during ingot cleaning, resulting in low material utilization rate and large defects in the castings, long production cycle; (2) Large ingots have many internal defects, which need to be eliminated by repeated upsetting and drawing, resulting in low manufacturing efficiency of the workpiece; (3) Core rod hole expansion and horse frame hole expansion are required during manufacturing, and repeated heating is required, resulting in high energy consumption and long production cycle; (4) During the plastic deformation process of ring rolling, the ring material is pressed in the radial direction of the press roll, and the material in the axial direction of the ring is free, which is not a three-way pressure stress, and the compactness is low, which cannot fully break the internal defects, resulting in low mechanical properties of large ring rolling.

[0004] Therefore, the traditional manufacturing method of large rings cannot meet the overall requirements of high efficiency, high performance, low energy consumption and low cost proposed by the market. SUMMARY

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a large centrifugal casting ring high-performance radial forging and semi-solid ring rolling composite process, which can prepare a large ring with non-dendritic, fine and dense, uniform and spherical microstructure, and has the advantages of high efficiency, high performance, low energy consumption and low cost.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A large centrifugal casting ring high-performance radial forging and semi-solid ring rolling composite process, comprising the following steps:

[0008] 1) adopting centrifugal casting process to prepare large circular cross-section ring blank;

[0009] 2) using the residual heat of centrifugal casting to conduct three-hammer-head radial forging plastic deformation on the large circular cross-section ring blank to obtain a large ring piece in a forged state;

[0010] 3) conducting secondary remelting on the large ring piece in a forged state to obtain a large ring piece semi-solid blank with fine, uniform and spherical microstructure;

[0011] 4) conducting semi-solid ring rolling forming on the large ring piece semi-solid blank to obtain a large rectangular cross-section ring piece;

[0012] 5) finally conducting ring rolling post-heat treatment on the large rectangular cross-section ring piece to finally prepare a large ring piece formed piece.

[0013] The step 1) is specifically as follows: the prepared 7055 aluminum alloy material is put into a medium-frequency induction melting furnace for melting at a melting temperature of 730℃ or above, and is kept for 40-60min for refining and degassing; then the aluminum alloy liquid 1-1 obtained by melting is poured into a centrifugal casting device with the temperature controlled at 700-710℃, and a large circular cross-section ring blank 1-2 is prepared by adopting the centrifugal casting process.

[0014] The step 2) is specifically as follows: when the temperature of the large circular cross-section ring blank 1-2 prepared in the step 1) is reduced to an initial forging temperature of 420-450℃, a large deformation plastic deformation of the large circular cross-section ring blank 1-2 is generated by adopting a three-hammer-head radial forging process, and the inner and outer diameters of the large circular cross-section ring blank 1-2 after the three-hammer-head radial forging are increased, and the circular cross-section diameter is reduced; the three-hammer-head radial forging process of the circular cross-section ring body includes three radial forging hammers 2-1 which are uniformly arranged along the center line of the circular cross-section of the large circular cross-section ring blank 1-2 in space, and the radial forging hammer 2-1 is an axial forming radial forging hammer; the specific process of the three-hammer-head radial forging process of the circular cross-section ring body is as follows:

[0015] 2.1) the three radial forging hammers 2-1 strike and forge the large circular cross-section ring blank 1-2 on the circular cross-section of the large circular cross-section ring blank 1-2, and the radial forging amount is a pre-set radial forging amount of this pass;

[0016] 2.2) the radial forging hammer 2-1 is lifted, the large circular cross-section ring blank 1-2 rotates by an angle α around its own axis, and at the same time, the three radial forging hammers 2-1 rotate by an angle β along the center line of the circular cross-section of the large circular cross-section ring blank 1-2; wherein the angle α and the angle β match each other, so that each circular cross-section of the large circular cross-section ring blank 1-2 can be effectively and uniformly forged in the circumferential direction;

[0017] 2.3) repeat step 2.1) - step 2.2) until the entire large circular cross-section ring blank 1-2 is enlarged in inner and outer diameter and reduced in circular cross-section diameter under the amount of radial forging of the present pass, and the ring body 1-2-1 is formed by the radial forging, and the radial forging of the present pass is completed;

[0018] 2.4) repeat step 2.1) - step 2.3) to complete the radial forging of the ring body of the subsequent pass; the amount of radial forging of each pass is preset, and the sum of the amount of radial forging of all passes is the total amount of radial forging; the plastic deformation of the large circular cross-section ring blank 1-2 is completed under the total amount of radial forging, and the reduction of area of the large ring forging state ring 1-3 obtained by the radial forging deformation is ensured to be more than 40%, so that the large ring forging state ring 1-3 is plastically deformed by a large deformation amount, and the deformation distortion energy is stored in the material organization.

[0019] The step 3) is specifically that the large ring forging state ring 1-3 obtained by the three-hammer-head radial forging in step 2.4) is placed into an electric furnace or a medium-frequency induction heating furnace for heating and heat preservation, wherein the heating temperature is controlled at 595-610℃, and the heat preservation time is 15-30min, so as to obtain the large ring semi-solid billet 1-4 with fine, uniform and spherical microstructure.

[0020] The step 4) is specifically that the large ring semi-solid billet 1-4 obtained by the secondary remelting in step 3) is quickly taken out and placed into a ring rolling device; the ring rolling device includes a driving roller 3-1, a guide roller 3-2, a core roller 3-3 and an axial taper roller 3-4, the driving roller 3-1 rotates around its own axis, thereby driving the large ring semi-solid billet 1-4 to rotate; the core roller 3-3 rotates while slowly moving towards the driving roller 3-1, and the radial rolling action of the driving roller 3-1 and the core roller 3-3 makes the wall thickness of the large ring semi-solid billet 1-4 thin, thereby controlling the diameter of the ring; a pair of guide rollers 3-2 plays a guiding role in the rotation of the large ring semi-solid billet 1-4; the height of the large ring semi-solid billet 1-4 is controlled through the axial rolling action of a pair of axial taper rollers 3-4; the large ring semi-solid billet 1-4 is subjected to semi-solid ring rolling forming through the ring rolling device, the circular cross-section of the large ring semi-solid billet 1-4 is plastically deformed into a rectangular cross-section, and the large rectangular cross-section ring 1-5 is obtained, and the grains are further refined.

[0021] The step 5) is specifically that the heat treatment after ring rolling includes solution and aging treatment, first, the large rectangular cross-section ring 1-5 obtained in step 4) is treated by adopting a two-stage solution process of 450℃ / 3h+495℃ / 0.5h, then the large rectangular cross-section ring 1-5 after the solution treatment is subjected to two-stage artificial aging treatment of 120℃ / 6h+160℃ / 6h, and finally the large ring forming piece 1-6 is obtained.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] (1) The present application adopts large centrifugal casting ring as the original blank, and there is almost no metal consumption of the pouring system and the riser system, the material utilization rate is high, and the centrifugal casting part has higher density than the cylindrical ingot, and has fewer defects such as porosity, pores and slag in the casting process, and no core is needed when producing hollow ring-shaped castings, which simplifies the production process of the castings and shortens the production cycle.

[0024] (2) The present application can effectively eliminate internal defects of the castings through the high-performance radial forging process, and the radial forging hammer head high-frequency forges the castings, and the forming efficiency is high.

[0025] (3) The present application effectively utilizes the centrifugal casting waste heat for radial forging forming, and the radial forging process itself is an energy-saving and efficient forming process, so the energy consumption of the whole manufacturing process is small, and the production cycle is short.

[0026] (4) The present application adopts the three-hammer-head radial forging process, and the ring material is subjected to three-way compressive stress, which can fully break the internal defects and make the microstructure small and dense, so that the mechanical properties of the large ring can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a manufacturing process schematic diagram of the present application embodiment from 7055 aluminum alloy liquid 1-1 to large ring forming part 1-6.

[0028] Figure 2 It is a hammer hitting forging schematic diagram of the present application embodiment three-hammer-head radial forging large circular cross-section ring blank 1-2.

[0029] Figure 3 It is a schematic diagram of the present application embodiment three-hammer-head radial forging large circular cross-section ring blank 1-2 hammer head lifting and workpiece and hammer head rotating.

[0030] Figure 4 It is a schematic diagram of the present application embodiment three-hammer-head radial forging large circular cross-section ring blank 1-2 current pass forging completion.

[0031] Figure 5 It is a schematic diagram of the semi-solid ring rolling adopted by the present application embodiment. DETAILED DESCRIPTION

[0032] The present application will be described in detail below with reference to the drawings and embodiments.

[0033] Referring to Figure 1 A large centrifugal casting ring high-performance radial forging and semi-solid ring rolling composite process takes 7055 aluminum alloy large ring as an example, and includes the following steps:

[0034] 1) Centrifugal casting to prepare large circular cross-section ring billets: Under the melting temperature of 730℃ or above, the pre-prepared 7055 aluminum alloy material is put into a medium frequency induction melting furnace for melting and holding for 40-60 minutes for refining and degassing; then the temperature of the molten aluminum alloy 1-1 is controlled at 700~710℃ and poured into a centrifugal casting equipment to prepare large circular cross-section ring billets 1-2 using centrifugal casting process;

[0035] 2) Utilizing residual heat from centrifugal casting for three-hammer radial forging plastic deformation: When the temperature of the large circular cross-section ring billet 1-2 prepared in step 1) drops to the initial forging temperature of 420-450℃, the large cast ring 1-2 obtained in step 1) undergoes large-scale plastic deformation through three-hammer radial forging. After three-hammer radial forging, the inner and outer diameters of the large circular cross-section ring billet 1-2 increase, and the diameter of the circular cross-section decreases, achieving the purpose of forging and closing internal defects in the cast billet, breaking dendrites in the microstructure, and making the microstructure fine and dense. Furthermore, the large plastic deformation after radial forging allows the material structure to store a large amount of deformation distortion energy; refer to Figure 2 The radial forging process of a circular cross-section ring with three hammers includes three radial forging hammers 2-1, which are evenly arranged in space along the centerline of the circular cross-section of the large circular cross-section ring blank 1-2. The radial forging hammers 2-1 are shaft-forming radial forging hammers. The specific process of the radial forging process of the circular cross-section ring with three hammers is as follows:

[0036] 2.1) Reference Figure 2 Three radial forging hammers 2-1 strike the large circular cross-section ring blank 1-2 on the circular cross-section of the large circular cross-section ring blank 1-2, and the radial forging amount is the preset radial forging amount for this pass.

[0037] 2.2) Reference Figure 3 The radial forging hammer 2-1 is lifted, and the large circular cross-section ring blank 1-2 rotates around its own axis by an angle α. At the same time, the three radial forging hammers 2-1 rotate by an angle β along the center line of the circular cross-section of the large circular cross-section ring blank 1-2. The angles α and β match each other, so that each circular cross-section of the large circular cross-section ring blank 1-2 can be effectively and uniformly forged in the circumferential direction.

[0038] 2.3) Reference Figure 4 Repeat steps 2.1)-2.2) until the inner and outer diameters of the entire large circular cross-section ring billet 1-2 become larger and the diameter of the circular cross-section becomes smaller under the radial forging amount in this pass, forming the ring body 1-2-1, and completing the radial forging of this pass;

[0039] 2.4) Repeat steps 2.1)-2.3) to complete the radial forging of the ring body in subsequent passes; the radial forging amount of each pass is preset, and the sum of the radial forging amounts of all passes is the total radial forging amount; under the total radial forging amount, complete the three-hammer radial forging plastic deformation of the large circular cross-section ring blank 1-2, ensuring that the section reduction rate of the large ring forged state ring 1-3 obtained after radial forging deformation reaches more than 40%, so that the large cast ring body produces large deformation plastic deformation and the material structure stores a large deformation distortion energy.

[0040] 3) Secondary remelting: The large ring forged state 1-3 obtained by radial forging with three hammers in step 2.4) is placed into an electric furnace or medium frequency induction heating furnace for heating and holding at a temperature of 595-610℃ and a holding time of 15-30min to obtain a large ring semi-solid billet 1-4 with fine, uniform, spherical microstructure.

[0041] 4) Semi-solid ring rolling forming of large rectangular cross-section rings 1-5: Refer to Figure 5 The large ring semi-solid billet 1-4 obtained from the secondary remelting in step 3) is quickly removed and placed into the ring rolling device. The ring rolling device includes a drive roller 3-1, a guide roller 3-2, a core roller 3-3, and an axial conical roller 3-4. The drive roller 3-1 rotates around its own axis, thereby driving the large ring semi-solid billet 1-4 to rotate. While the core roller 3-3 rotates, it slowly moves towards the drive roller 3-1. Through the radial rolling action of the drive roller 3-1 and the core roller 3-3, the large ring semi-solid billet 1-4 is rolled. 4. Wall thickness reduction to control ring diameter; a pair of guide rollers 3-2 guide the rotation of the large ring semi-solid blank 1-4; the height of the large ring semi-solid blank 1-4 is controlled by the axial rolling action of a pair of axial tapered rollers 3-4; the large ring semi-solid blank 1-4 is semi-solid rolled into a ring by a rolling device, and the circular cross section of the large ring semi-solid blank 1-4 is plastically deformed into a rectangular cross section after rolling, resulting in a large rectangular cross section ring 1-5, and the grains are further refined;

[0042] 5) Heat treatment after ring rolling: including solution treatment and aging treatment. First, the large rectangular cross-section ring 1-5 obtained in step 4) is treated by a two-stage solution treatment process of 450℃ / 3h + 495℃ / 0.5h. Then, the large rectangular cross-section ring 1-5 after solution treatment is subjected to two-stage artificial aging treatment of 120℃ / 6h + 160℃ / 6h, and finally the large ring forming part 1-6 is obtained.

[0043] The above description is only an example of the present invention using 7055 aluminum alloy, and is not intended to limit the scope of protection of the present invention. For other metal materials such as copper alloys and aluminum alloys used to manufacture large ring components, as long as the corresponding process parameters are matched, they are also included within the scope of protection of the present invention.

Claims

1. A composite process for high-performance radial forging and semi-solid ring rolling of large centrifugal casting rings, characterized in that, Includes the following steps: 1) A large circular cross-section ring blank was prepared using centrifugal casting process; 2) Utilize the residual heat from centrifugal casting to perform radial forging plastic deformation on a large circular cross-section ring blank using a three-hammer head to obtain a large ring in forged state; Step 2) specifically involves: when the temperature of the large circular cross-section ring blank (1-2) prepared in step 1) drops to the initial forging temperature, a three-hammer radial forging process is used to induce a large amount of plastic deformation in the large circular cross-section ring blank (1-2). After the three-hammer radial forging, the inner and outer diameters of the large circular cross-section ring blank (1-2) increase, and the diameter of the circular cross-section decreases. The three-hammer radial forging process of the circular cross-section ring includes three radial forging hammers (2-1), which are evenly arranged in space along the center line of the circular cross-section of the large circular cross-section ring blank (1-2). The radial forging hammers (2-1) are shaft-forming radial forging hammers. The specific process of the three-hammer radial forging process of the circular cross-section ring is as follows: 2.1) Three radial forging hammers (2-1) strike the large circular cross-section ring blank (1-2) on the circular cross-section of the large circular cross-section ring blank (1-2) for forging. The radial forging amount is the pre-set radial forging amount for this pass. 2.2) The radial forging hammer (2-1) is lifted, and the large circular cross-section ring blank (1-2) rotates around its own axis by an angle α. At the same time, the three radial forging hammers (2-1) rotate by an angle β along the center line of the circular cross-section of the large circular cross-section ring blank (1-2). The angles α and β are matched with each other, so that each circular cross-section of the large circular cross-section ring blank (1-2) can be effectively and uniformly forged in the circumferential direction. 2.3) Repeat steps 2.1)-2.2) until the inner and outer diameters of the entire large circular cross-section ring blank (1-2) increase and the diameter of the circular cross-section decreases under the radial forging amount in this pass, forming a ring (1-2-1), thus completing the radial forging of this pass; 2.4) Repeat steps 2.1)-2.3) to complete the radial forging of the ring body in subsequent passes; the radial forging amount of each pass is preset, and the sum of the radial forging amounts of all passes is the total radial forging amount; under the total radial forging amount, complete the three-hammer radial forging plastic deformation of the large circular cross-section ring blank (1-2) to ensure that the section reduction rate of the large ring forged state ring (1-3) obtained after radial forging deformation reaches more than 40%, so that the large ring forged state ring (1-3) produces plastic deformation with large deformation amount and stores deformation distortion energy inside the material structure; 3) The forged ring is remelted twice to obtain a semi-solid billet of the large ring with a fine, uniform, spherical microstructure. 4) Large rectangular cross-section rings are formed from semi-solid blanks of large ring components through semi-solid ring rolling. 5) Finally, the large rectangular cross-section ring is rolled and then heat-treated to produce the final large ring-shaped part.

2. The process according to claim 1, characterized in that, Step 1) specifically involves: melting the pre-prepared 7055 aluminum alloy material in a medium-frequency induction melting furnace at a melting temperature of 730℃ or above, holding it at the temperature for 40-60 minutes for refining and degassing; then pouring the molten aluminum alloy (1-1) at a temperature of 700-710℃ into a centrifugal casting device, and using the centrifugal casting process to prepare a large circular cross-section ring billet (1-2).

3. The process according to claim 2, characterized in that, In step 2), the initial forging temperature is 420–450°C.

4. The process according to claim 3, characterized in that, Step 3) specifically involves placing the large ring forged state (1-3) obtained by radial forging with three hammers in step 2.4) into an electric furnace or a medium-frequency induction heating furnace for heating and holding at a temperature of 595-610℃ and a holding time of 15-30 minutes to obtain a large ring semi-solid billet (1-4) with a fine, uniform, spherical microstructure.

5. The process according to claim 4, characterized in that, Step 4) specifically involves: quickly removing the large ring semi-solid billet (1-4) obtained from the secondary remelting in step 3) and placing it into the ring rolling device; the ring rolling device includes a drive roller (3-1), a guide roller (3-2), a core roller (3-3), and an axial conical roller (3-4). The drive roller (3-1) rotates around its own axis, thereby driving the large ring semi-solid billet (1-4) to rotate; while the core roller (3-3) rotates, it slowly moves towards the drive roller (3-1), and the large ring is rolled by the radial rolling action of the drive roller (3-1) and the core roller (3-3) to form a ring. The wall thickness of the semi-solid blank (1-4) is reduced to control the diameter of the ring; a pair of guide rollers (3-2) guide the rotation of the large ring semi-solid blank (1-4); the height of the large ring semi-solid blank (1-4) is controlled by the axial rolling action of a pair of axial conical rollers (3-4); the large ring semi-solid blank (1-4) is semi-solid rolled into a ring by a rolling device, and the circular cross section of the large ring semi-solid blank (1-4) is plastically deformed into a rectangular cross section after rolling, resulting in a large rectangular cross section ring (1-5), and the grains are further refined.

6. The process according to claim 5, characterized in that, Step 5) specifically involves the heat treatment after ring rolling, which includes solution treatment and aging treatment. First, the large rectangular cross-section ring (1-5) obtained in step 4) is treated with a two-stage solution treatment process of 450℃ / 3h + 495℃ / 0.5h. Then, the large rectangular cross-section ring (1-5) after solution treatment is subjected to a two-stage artificial aging treatment of 120℃ / 6h + 160℃ / 6h, and finally the large ring forming part (1-6) is obtained.

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