Manufacturing method of beta-forged TC25 annular forge piece

Abstract

The invention relates to the technical field of special-shaped forge piece manufacturing processes, in particular to a manufacturing method of a beta-forged TC25 annular forge piece. The invention provides a process method for stably producing beta forged TC25 annular forgings. The process method comprises the steps of blanking, heating, upsetting and punching, heating, trestle chambering, heating, finish rolling and double annealing. According to the finally produced TC25 annular forge piece, the size of the produced forge piece is good and stable, according to high-magnification structure detection, a base body is basically of a basket structure and contains a small amount of primary alpha phase, the room-temperature strength and the high-temperature strength are both improved, other performance is qualified, and a certain margin is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of special-shaped forging manufacturing process, in particular to a manufacturing method of a beta-forged TC25 ring forging. Background Art

[0002] TC25 titanium alloy is a Ti-Al-Zr-Sn-Mo-W-Si series (+β) martensitic heat-resistant titanium alloy with excellent comprehensive properties. Its nominal composition is Ti-6.5Al-2Zr-2Sn-2Mo-1W-0.2Si. It has the high thermal strength of TC11 alloy and the thermal stability of TC8 alloy. It is suitable for making engine parts and can be used for a long time at 500℃~550℃. Below 550℃, the alloy has good room temperature properties, creep properties, fatigue properties and fracture toughness matching. Under appropriate deformation and heat treatment conditions, a more ideal comprehensive performance can be obtained.

[0003] At present, in engineering manufacturing, TC25 titanium alloy ring forgings generally use the α+β two-phase ring forging method. However, with the development of engines, the strength of TC25 ring forgings produced by conventional α+β two-phase regions can no longer meet the design requirements for TC25 ring forgings. β-phase forging is required to produce TC25 ring forgings with higher strength. The TC25 ring forgings produced by the α+β two-phase forging method have good and stable dimensions after production. After high-power organization testing, the matrix is ​​basically a uniform dual-state organization, containing a large amount of primary α phase, and the mechanical properties are qualified, but the margin is small.

[0004] The TC25 ring forgings produced by the β phase forging method have good and stable dimensions after production. After high-power organization inspection, the matrix is ​​basically a basketweave organization, containing a small amount of primary α phase, and the room temperature and high temperature strengths are improved. Other properties are qualified and have a large margin. Therefore, finding an excellent manufacturing method for β-forged TC25 ring forgings is the current key research direction. Summary of the invention

[0005] In order to solve the above technical problems existing in the prior art, the present invention provides a method for manufacturing a β-forged TC25 ring forging, comprising the following steps:

[0006] A method for manufacturing a β-forged TC25 ring forging comprises the following steps:

[0007] (1) Cutting materials;

[0008] (2) First heating: heating temperature is T β -(30±10)℃;

[0009] (3) Roughening and punching: roughening and punching the blank after the first heating;

[0010] (4) Second heating: The blank after upsetting and punching is heated for the second time; the temperature is T β +(20±10)℃; Select T β +(20±10)℃ is to completely eliminate the primary α phase brought by the raw materials and prepare the organization for the subsequent final rolling;

[0011] (5) Horse rack hole expansion: Horse rack hole expansion must be completed quickly. The entire horse rack process is 3 rounds. The time from the start of horse rack hole expansion to the end of horse rack hole expansion should not exceed 150 seconds. Ensure that the final forging temperature is ≥950℃;

[0012] (6) Third heating: The blank after the hole expansion is heated for the third time; the heating temperature is selected as T β ±10℃;

[0013] (7) Final rolling: During the final rolling of the billet, the initial biting stage is slowly biting in, so that the inner diameter of the ring is relatively slowly increased. After a short period, it enters the main rolling stage. This stage completes the rolling quickly, and the remaining inner diameter is increased in a short time. The third stage, the shaping stage, is completed quickly, and the shaping is completed within 5s to 7s.

[0014] (8) Double annealing: The forgings obtained after final rolling are subjected to double annealing treatment. The first annealing is carried out at 965°C and the cooling method is air cooling. The second annealing is carried out at 555°C and the cooling method is air cooling.

[0015] Furthermore, the medium T β is the phase transition point temperature.

[0016] Furthermore, in step (3), the ratio of the height after roughening to the height after final rolling is 1.1 ≥ H 1 / H 2 ≥1.3, where the height of the blank after roughening and before punching is H 1 , the billet height after final rolling is H 2 If the ratio is too low, the blank may have angle collapse defects after final rolling. If the ratio is too high, the cone roll will have too much workload during subsequent ring rolling, requiring the ring rolling mill to have a large axial pressure. In addition, the end surface of the blank will be too hot due to rapid deformation, resulting in uneven organization of various parts of the ring.

[0017] Furthermore, in step (5), this process reserves 20% to 30% of deformation for the final rolling process.

[0018] Furthermore, the step (1) is to cut the material into a size of Φ200mm×103mm, and after cutting, the two end surfaces are rounded (R8~R10)mm.

[0019] Furthermore, in steps (2), (4) and (6), the heating and heat preservation time is calculated according to 0.6×effective wall thickness+(30-180) min.

[0020] Furthermore, in step (3), a punch with a diameter of Φ (100-110) mm is selected for punching.

[0021] Furthermore, the step (5) is to produce the blank to a size of Φ(355±5)mm×Φ(230±5)mm×60mm by using a horse rack expansion method. The horse rack expansion is completed within 3 turns. The first turn of the horse rack expansion has a reduction of (4-6)mm, the second turn of the horse rack expansion has a reduction of (6-8)mm, and the third turn of the horse rack expansion completes the remaining reduction.

[0022] Furthermore, the step (7) is specifically to use a rolling mill to roll the billet to Φ(410±5)mm×Φ(320±5)mm×(58±5)mm; during rolling, in the initial biting stage, the biting should be slow, and the ring should grow by 30mm in about 30s. After 30s, the main rolling stage is entered. This stage needs to be rolled quickly, and the inner diameter length of about 70mm is completed within 20s. The third stage shaping stage should be completed quickly, and the shaping is completed within 5s to 7s.

[0023] Compared with the prior art, the technical effects created by the present invention are embodied in:

[0024] At present, the conventional production of TC25 ring forgings generally uses the α+β two-phase region ring forging method. However, with the development of engines, the conventional α+β two-phase region production of TC25 ring forgings can no longer meet the design requirements for the use of TC25 ring forgings, especially for external sealing comb ring forgings. Higher requirements are put forward, and β phase region forging is required to produce TC25 ring forgings with higher strength. The TC25 ring forgings produced by the present application through a specific β phase region forging method have good and stable dimensions after production. After high-power organization detection, the matrix is ​​basically a basket structure containing a small amount of primary α phase, the room temperature and high temperature strengths are improved, and other properties are qualified with a certain margin. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The rolling curve diagram of Example 1

[0026] Figure 2 This is a high-magnification tissue detection image of the product obtained in Example 1. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further defined below in conjunction with specific implementation methods, but the scope of protection required is not limited to the description.

[0028] Example 1

[0029] (1) Cutting

[0030] Cut the material according to the size of Φ200mm×103mm. After cutting, both end surfaces need to be rounded (R8~R10)mm.

[0031] (2) First heating

[0032] Heating is performed at (30±10)°C below the phase change point, and the heating and holding time is calculated according to 0.6×effective wall thickness+(30~180)min to ensure that the blank is heated through as a whole.

[0033] (3) Upsetting and punching

[0034] The blank is upset to a height of H1 = (66 ± 5) mm, H 1 / H 2 =(66±5) / (58±5)≈1.138, a punch with a diameter of Φ(100~110)mm is selected for punching;

[0035] (4) Second heating

[0036] Heating is performed at (25±10)℃ above the phase change point (the phase change point needs to be the highest value in the original certificate and the re-test results), and the holding time is calculated as 0.6×effective wall thickness+(30~180)min;

[0037] (5) Horse rack hole expansion

[0038] The blank is produced to the size of Φ(355±5)mm×Φ(230±5)mm×60mm by the method of horse frame expansion.

[0039] The reaming of the horse frame should be completed within 3 rounds. The first round of the reaming is (4-6) mm, the second round of the reaming is (6-8) mm, and the third round of the reaming is completed. After the reaming is completed, the final forging temperature must be ≥950℃.

[0040] (6) Third heating

[0041] The phase transition temperature (T β )±10℃, and the heating and holding time is calculated according to 0.6×effective wall thickness+(30~180)min.

[0042] (7) Final rolling

[0043] The billet is rolled into Φ(410±5)mm×Φ(320±5)mm×(58±5)mm using a rolling mill.

[0044] During rolling, the initial biting stage should be bitten slowly, and the ring should grow by 30mm in about 30 seconds. After 30 seconds, it enters the main rolling stage. In this stage, the rolling should be completed quickly, and the inner diameter of about 70mm should be completed within 20 seconds. The third stage of shaping should be completed quickly, and shaping should be completed within 5s to 7s. The rolling curve is shown in Figure 1 .

[0045] (8) Double annealing

[0046] The obtained forgings were subjected to double annealing after final rolling. The first annealing was carried out at 965°C for 130 minutes and air cooling, and the second annealing was carried out at 555°C for 6.5 hours and air cooling.

[0047] The TC25 ring forgings produced by this method have good and stable dimensions after production. After high-power microstructure testing, the matrix is ​​basically a basketweave structure with a small amount of primary α phase (see Figure 2 ), all performances are qualified (see the table below), and all have a certain degree of abundance.

[0048]

[0049]

[0050] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the technical solution of the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A method for manufacturing a β-forged TC25 ring forging, characterized in that: The steps include: (1) Cutting materials; (2) First heating: heating temperature is T β -(30±10)℃; (3) Roughening and punching: roughening and punching the blank after the first heating; (4) Second heating: The blank after upsetting and punching is heated for the second time; the temperature is T β +(20±10)℃; (5) Horse rack hole expansion: Horse rack hole expansion must be completed quickly. The entire horse rack process is 3 rounds. The time from the start of horse rack hole expansion to the end of horse rack hole expansion should not exceed 150 seconds. Ensure that the final forging temperature is ≥950℃; (6) Third heating: The blank after the hole expansion is heated for the third time; the heating temperature is selected as T β ±10℃; (7) Final rolling: During the final rolling of the billet, the initial biting stage is slowly biting in, so that the inner diameter of the ring is relatively slowly increased. After a short period, it enters the main rolling stage. This stage completes the rolling quickly, and the remaining inner diameter is increased in a short time. The third stage, the shaping stage, is completed quickly, and the shaping is completed within 5s to 7s. (8) Double annealing: The forgings obtained after final rolling are subjected to double annealing treatment. The first annealing is carried out at 965°C and the cooling method is air cooling. The second annealing is carried out at 555°C and the cooling method is air cooling.

2. The method for manufacturing a β-forged TC25 ring forging according to claim 1, characterized in that: The medium T β is the phase transition point temperature.

3. The method for manufacturing a β-forged TC25 ring forging according to claim 2, characterized in that: In the step (3), the ratio of the height after upsetting to the height after final rolling is 1.1≥H1 / H2≥1.3, wherein the height of the billet after upsetting and before punching is H1, and the height of the billet after final rolling is H2.

4. The method for manufacturing a β-forged TC25 ring forging according to claim 1, characterized in that: The step (5) reserves 20% to 30% of deformation for the final rolling process.

5. The method for manufacturing a β-forged TC25 ring forging according to claim 1, characterized in that: The step (1) specifically involves cutting the material into a size of Φ200mm×103mm. After cutting, both end surfaces are rounded (R8~R10)mm.

6. The method for manufacturing a beta forged TC25 ring forging according to claim 1, characterized in that: In the steps (2), (4) and (6), the heating and heat preservation time is calculated as 0.6×effective wall thickness+(30-180) min.

7. The method for manufacturing a beta forging TC25 ring forging according to claim 1, characterized in that: In the step (3), a punch having a diameter of Φ (100-110) mm is selected for punching.

8. The method for manufacturing a beta forged TC25 ring forging according to claim 1, characterized in that: The step (5) specifically adopts the method of horse rack expansion to produce the blank to the size of Φ(355±5)mm×Φ(230±5)mm×60mm, and the horse rack expansion is completed within 3 circles, the first circle of horse rack expansion has a reduction of (4~6)mm, the second circle of horse rack expansion has a reduction of (6~8)mm, and the third circle of horse rack expansion completes the remaining reduction.

9. The method for manufacturing a beta forging TC25 ring forging according to claim 1, characterized in that: The step (7) is specifically to use a rolling mill to roll the billet to Φ(410±5)mm×Φ(320±5)mm×(58±5)mm; during rolling, in the initial biting stage, the biting should be slow, and the ring should grow by 30mm in about 30s. After 30s, the main rolling stage is entered. This stage needs to be rolled quickly, and the inner diameter length of about 70mm is completed within 20s. The third stage shaping stage should be completed quickly, and the shaping is completed within 5s to 7s.

Images