Large high-temperature alloy bar for ultra-fine grain gas turbine and forging method of large high-temperature alloy bar

Abstract

The invention discloses a high-temperature alloy large bar for an ultra-fine grain gas turbine and a forging method of the high-temperature alloy large bar, and belongs to the technical field of high-temperature alloy preparation. According to the method, for high-temperature alloys such as GH4169, a composite nucleation refiner composed of yttrium oxide (YO) and boron carbide (BC) is added in the vacuum induction smelting stage, and through the steps of optimized homogenization treatment, multi-heating-number variable-temperature upsetting and drawing forging, temperature-controlled rolling forming and the like, grain ultra-fining and high structure uniformity of the section of the large bar are achieved in a synergistic mode. The method has the advantages that the average grain size of the prepared large bar with the diameter of 350-450 mm reaches 8.0-9.0 grade, the grain size grade difference is smaller than or equal to 1.0 grade, the transverse mechanical property and the high-temperature creep property of the material are remarkably improved, the lasting fracture time at the temperature of 650 DEG C is longer than 280 h, the percentage elongation after fracture is larger than 18%, the problem of high flaw detection clutter caused by coarse grains is effectively solved, and flaw detection meets the AA-grade requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-temperature alloy preparation, in particular to a kind of super fine grain high-temperature alloy big stick for gas turbine and its forging method. BACKGROUND

[0002] High-temperature alloy big stick is the base material for manufacturing key components such as large turbine disk of gas turbine, which are subjected to high temperature, high stress, hot corrosion and complex cyclic load during service. Therefore, the turbine disk material not only requires high strength, but also needs excellent high-temperature creep performance, fatigue performance and uniform longitudinal and transverse mechanical properties.

[0003] GH4169 (similar to international brand Inconel 718) is a high-temperature alloy widely used in such components. However, for GH4169 rods with large cross-section (such as diameter of 350 mm or more), it is difficult to obtain uniform and fine grain structure throughout the cross-section by traditional forging method. Common problems include: coarse grains, serious mixed grains (large grain size difference), insufficient transverse mechanical properties (especially endurance performance and plasticity), and high ultrasonic flaw detection noise level due to uneven structure, which is difficult to meet the strict AA-level flaw detection standard in the fields of aviation, gas turbine and the like. In addition, the rod exhibits transverse high-temperature endurance notch sensitivity at about 650℃, with low endurance life and plasticity, affecting the safe service life of the component.

[0004] Currently, the structure is improved mainly by optimizing forging process parameters (such as temperature, deformation amount, deformation rate). However, for super large size rods, the deformation and cooling conditions of the core and the surface are greatly different, and it is difficult to achieve full recrystallization and grain refinement of the core by physical deformation alone. Although there are attempts to use a single nucleating agent in the prior art, the effect is limited, and ideal grain refinement and grain boundary strengthening cannot be achieved. Therefore, there is an urgent need for an innovative method that can synergistically act from both the material essence and the processing technology to achieve full-section ultra-fine grain and high-uniform structure of large rods. SUMMARY

[0005] To solve the problems of coarse grains, uneven structure, poor transverse performance and low flaw detection qualification rate of high-temperature alloy big stick in the prior art, the present application provides a kind of super fine grain high-temperature alloy big stick for gas turbine and its forging method.

[0006] The technical solution adopted by the present application is: a forging method of a super fine grain high-temperature alloy big stick for gas turbine, comprising the following steps: Step A: homogenizing the consumable ingot after vacuum induction smelting and vacuum consumable remelting; wherein, during the vacuum induction smelting, a composite nucleation refiner is added, the composite nucleation refiner is added in an amount of 0.001% to 0.015% of the mass of the consumable ingot; the composite nucleation refiner is composed of yttrium oxide and boron carbide in a mass ratio of 1:0.2 to 0.7; Step B: re-heating the homogenized consumable ingot to a forging temperature and keeping the temperature; Step C: first high-temperature upsetting and drawing forging, and then middle-temperature upsetting and drawing forging after cooling; Step D: low-temperature upsetting of the forged alloy blank, and then multi-pass elongation forming and drop round forging after cooling; Step E: air cooling the formed alloy rod to room temperature, and then flaw detection and sampling; Step F: heat treatment of the sampling sample, and metallographic structure and performance detection.

[0007] As a further improvement of the present application, in Step A, the homogenization treatment is: heating the consumable ingot to 1150 to 1170℃, keeping the temperature for more than 30 hours, then heating to 1180 to 1200℃, keeping the temperature for more than 72 hours, and then furnace cooling after completion.

[0008] As a further improvement of the present application, in Step B, the re-heating is: heating the finished consumable ingot to 1100 to 1120℃, keeping the temperature for more than 4 hours.

[0009] As a further improvement of the present application, in Step C, the high-temperature upsetting and drawing forging is two upsetting and two drawing at 1100 to 1120℃; the middle-temperature upsetting and drawing forging is one upsetting and one drawing after cooling to 1040 to 1090℃.

[0010] As a further improvement of the present application, in Step D, the low-temperature upsetting is: keeping the blank at 1010 to 1040℃, reducing the core temperature to 1010 to 1040℃, keeping the temperature for more than 3 hours, and then one upsetting and one drawing; the multi-pass elongation forming and drop round forging is performed at 980 to 990℃, and the surface temperature drop is reduced by using tooling baking and soft packing measures during forging, and the pass deformation amount is controlled to be 7% to 12%.

[0011] As a further improvement of the present application, in Step E, the flaw detection is AA-level ultrasonic flaw detection of the finished rod; the sampling is: cutting off the head and tail of the rod by 150 to 250 mm using a sawing machine, and then cutting a round sample with a thickness of 15 to 25 mm.

[0012] As a further improvement of the present invention, in step F, the heat treatment is to perform solid solution and aging treatment on the circular sample; the solid solution treatment conditions are to keep it at 950-980℃ for 1-2 hours; the metallographic structure and performance testing include taking samples from the center, half radius and edge of the circular sample, observing the grain size and testing the transverse mechanical properties.

[0013] As will be readily understood by those skilled in the art, the high-temperature alloy described in this invention can be GH4169 alloy.

[0014] This invention also discloses a high-temperature alloy bar for ultrafine-grained gas turbines, which is prepared by the forging method described above. Experiments show that its average grain size is 8.0–9.0 grade, the grain size difference is ≤1.0 grade, the creep rupture time at 650℃ is greater than 280 hours, the elongation after fracture is greater than 18%, and the ultrasonic testing meets the AA grade requirements.

[0015] The beneficial effects of this invention are: 1) Through the synergistic effect of a composite nucleation refiner and an optimized multi-stage variable-temperature forging process, ultra-fine grain size (average grade 8.0–9.0) and high uniformity (grade difference ≤ 1.0) are achieved across the entire cross-section of large-section bars. 2) The prepared bars exhibit excellent transverse mechanical properties and high-temperature creep performance, completely eliminating notch sensitivity during transverse high-temperature creep at 650℃, resulting in significantly improved creep life and plasticity. 3) The bars have a uniform and dense microstructure, low ultrasonic testing noise, and can stably meet the AA-level flaw detection standard, making them suitable for manufacturing key components such as high-performance gas turbine turbine disks. Detailed Implementation

[0016] The present invention will be further described below with reference to embodiments.

[0017] Example 1: Large bars of ultrafine-grained GH4169 high-temperature alloy for gas turbines were prepared using the following method: S1. Raw Material Preparation and Smelting: GH4169 alloy was smelted using a vacuum induction furnace (VIM). A composite nucleation refining agent was added during the later stages of refining, with the amount added being 0.008% of the consumable ingot mass. The composite nucleation refining agent consisted of yttrium oxide and boron carbide in a mass ratio of 1:0.4. After casting into electrode rods, vacuum arc remelting (VAR) was performed to produce consumable ingots with a diameter of φ508mm.

[0018] S2. Homogenization treatment: The consumable ingots are loaded into a heating furnace and heated to 1160°C at a rate of 80°C / h, and held for 38 hours; then the temperature is increased to 1190°C at a rate of 50°C / h, and held for 80 hours; after completion, the ingots are cooled to 500°C at a rate of 30°C / h before being removed from the furnace.

[0019] S3. Billet preparation: After homogenization and polishing, the consumable ingot is put back into the heating furnace and heated to 1110℃ for 6 hours.

[0020] S4. Multi-stage upsetting and drawing forging: "Two upsetting and two drawing" forging is carried out at 1110℃ (deformation amount of about 35% per heat). Then the temperature is reduced to 1070℃ and "one upsetting and one drawing" forging is carried out (deformation amount of about 30% per heat) to obtain the preliminary billet.

[0021] S5. Forming and Forging: The billet is placed in a heating furnace and heated at 1030℃ for 5 hours to allow the core temperature to drop to 1030℃. Then, it undergoes a "one-upset-one-drawing" forging process. The temperature is then lowered to 985℃, and at this temperature, it is drawn in three passes and then rounded to the target size of φ400mm. During the forging process, the anvil is baked (220℃) and the billet is insulated with a soft sleeve to control the deformation per pass within 8% to 10%.

[0022] S6. Post-treatment: After forging, the bar is air-cooled to room temperature. After machining, ultrasonic testing is performed. After the test results reach AA grade, the end 200mm of material is cut off, and φ400×20mm round samples are cut out.

[0023] S7. Sample Preparation: The circular sample is heat-treated: solution treated at 975℃ for 1.5h, followed by oil cooling; then aged according to standard. Metallographic and mechanical property samples are cut from the center, 1 / 2R, and edge of the heat-treated circular sample.

[0024] Example 2: Large bars of ultrafine-grained GH4169 high-temperature alloy for gas turbines were prepared using the following method: S1. Raw Material Preparation and Smelting: GH4169 alloy was smelted using a vacuum induction furnace (VIM). A composite nucleation refining agent was added during the later stages of refining, with the amount added being 0.005% of the consumable ingot mass. The composite nucleation refining agent consisted of yttrium oxide and boron carbide in a mass ratio of 1:0.2. After casting into electrode rods, vacuum arc remelting (VAR) was performed to produce consumable ingots with a diameter of φ508mm.

[0025] S2. Homogenization treatment: Heat to 1165℃ and hold for 35 hours, then heat to 1195℃ and hold for 75 hours, then cool in the furnace.

[0026] S3. Blank preparation: After finishing, reheat to 1115℃ and heat evenly for 5 hours.

[0027] S4. Multi-stage upsetting and drawing of billet: "Two upsettings and two drawings" are performed at 1115℃. The temperature is then lowered to 1080℃ for "one upsetting and one drawing".

[0028] S5. Forming and forging: After uniform heating at 1020℃ for 4 hours, perform one upsetting and drawing. Cool down to 988℃ and perform two drawing and shaping operations to φ380mm. Use tooling for baking and sheathing to control the deformation amount per pass to 9%~11%.

[0029] S6. Post-processing: Air cooling, machining, and cutting the sample after passing AA-level flaw detection.

[0030] S7. Sample preparation: Same as in Example 1.

[0031] Example 3: Large bars of ultrafine-grained GH4169 high-temperature alloy for gas turbines were prepared using the following method: S1. Raw Material Preparation and Smelting: GH4169 alloy was smelted using a vacuum induction furnace (VIM). A composite nucleation refining agent was added during the later stages of refining, with the amount added being 0.012% of the consumable ingot mass. The composite nucleation refining agent consisted of yttrium oxide and boron carbide in a mass ratio of 1:0.6. After casting into electrode rods, vacuum arc remelting (VAR) was performed to produce consumable ingots with a diameter of φ508mm.

[0032] S2. Homogenization treatment: Heat to 1155℃ and hold for 40 hours, then heat to 1185℃ and hold for 85 hours, then cool in the furnace.

[0033] S3. Blank preparation: After machining, reheat to 1105℃ and heat evenly for 7 hours.

[0034] S4. Multi-stage upsetting and drawing of billet: "Two upsettings and two drawings" are performed at 1105℃. The temperature is then lowered to 1060℃ for "one upsetting and one drawing".

[0035] S5. Forming and forging: After uniform heating at 1040℃ for 6 hours, perform one upsetting and drawing. Cool down to 982℃ and perform four rounds of drawing and shaping to φ420mm. Use tooling for baking and sheathing to control the deformation amount per pass to 7%~9%.

[0036] S6. Post-processing: Air cooling, machining, and cutting the sample after passing AA-level flaw detection.

[0037] S7. Sample preparation: Same as in Example 1.

[0038] Comparative Example 1: The difference between this comparative example and Example 1 is that no nucleating refining agent is added during the VIM smelting process. The remaining steps and parameters are exactly the same as in Example 1, as detailed below: S1. Raw material preparation and smelting: GH4169 alloy is smelted in a vacuum induction furnace (VIM), cast into electrode rods, and then vacuum arc remelting (VAR) is performed to produce φ508mm arc remelting ingots.

[0039] S2. Homogenization treatment: The consumable ingots are loaded into a heating furnace and heated to 1160°C at a rate of 80°C / h, and held for 38 hours; then the temperature is increased to 1190°C at a rate of 50°C / h, and held for 80 hours; after completion, the ingots are cooled to 500°C at a rate of 30°C / h before being removed from the furnace.

[0040] S3. Billet preparation: After homogenization and polishing, the consumable ingot is put back into the heating furnace and heated to 1110℃ for 6 hours.

[0041] S4. Multi-stage upsetting and drawing forging: "Two upsetting and two drawing" forging is carried out at 1110℃ (deformation amount of about 35% per heat). Then the temperature is reduced to 1070℃ and "one upsetting and one drawing" forging is carried out (deformation amount of about 30% per heat) to obtain the preliminary billet.

[0042] S5. Forming and Forging: The billet is placed in a heating furnace and heated at 1030℃ for 5 hours to allow the core temperature to drop to 1030℃. Then, it undergoes a "one-upset-one-drawing" forging process. The temperature is then lowered to 985℃, and at this temperature, it is drawn in three passes and then rounded to the target size of φ400mm. During the forging process, the anvil is baked (220℃) and the billet is insulated with a soft sleeve to control the deformation per pass within 8% to 10%.

[0043] S6. Post-treatment: After forging, the bar is air-cooled to room temperature. After machining, ultrasonic testing is performed. After the test results reach AA grade, the end 200mm of material is cut off, and φ400×20mm round samples are cut out.

[0044] S7. Sample Preparation: The circular sample is heat-treated: solution treated at 975℃ for 1.5h, followed by oil cooling; then aged according to standard. Metallographic and mechanical property samples are cut from the center, 1 / 2R, and edge of the heat-treated circular sample.

[0045] Comparative Example 2: The difference between this comparative example and Example 1 is that only yttrium oxide (Y₂O₃) is used as the nucleation refiner, boron carbide is not added, and the amount of nucleation refiner added is the same as in Example 1. The remaining steps and parameters are exactly the same as in Example 1. Specifically, as follows: S1. Raw material preparation and smelting: GH4169 alloy is smelted in a vacuum induction furnace (VIM). In the later stage of refining, yttrium oxide, a nucleating and refining agent, is added at an amount of 0.008% of the mass of the consumable ingot. Vacuum consumable remelting (VAR) is then carried out to produce consumable ingots with a diameter of φ508mm.

[0046] S2. Homogenization treatment: The consumable ingots are loaded into a heating furnace and heated to 1160°C at a rate of 80°C / h, and held for 38 hours; then the temperature is increased to 1190°C at a rate of 50°C / h, and held for 80 hours; after completion, the ingots are cooled to 500°C at a rate of 30°C / h before being removed from the furnace.

[0047] S3. Billet preparation: After homogenization and polishing, the consumable ingot is put back into the heating furnace and heated to 1110℃ for 6 hours.

[0048] S4. Multi-stage upsetting and drawing forging: "Two upsetting and two drawing" forging is carried out at 1110℃ (deformation amount of about 35% per heat). Then the temperature is reduced to 1070℃ and "one upsetting and one drawing" forging is carried out (deformation amount of about 30% per heat) to obtain the preliminary billet.

[0049] S5. Forming and Forging: The billet is placed in a heating furnace and heated at 1030℃ for 5 hours to allow the core temperature to drop to 1030℃. Then, it undergoes a "one-upset-one-drawing" forging process. The temperature is then lowered to 985℃, and at this temperature, it is drawn in three passes and then rounded to the target size of φ400mm. During the forging process, the anvil is baked (220℃) and the billet is insulated with a soft sleeve to control the deformation per pass within 8% to 10%.

[0050] S6. Post-treatment: After forging, the bar is air-cooled to room temperature. After machining, ultrasonic testing is performed. After the test results reach AA grade, the end 200mm of material is cut off, and φ400×20mm round samples are cut out.

[0051] S7. Sample Preparation: The circular sample is heat-treated: solution treated at 975℃ for 1.5h, followed by oil cooling; then aged according to standard. Metallographic and mechanical property samples are cut from the center, 1 / 2R, and edge of the heat-treated circular sample.

[0052] Comparative Example 3: The difference between this comparative example and Example 1 is that only boron carbide (B4C) is used as the nucleation refiner, yttrium oxide is not added, and the amount of nucleation refiner added is the same as in Example 1. The remaining steps and parameters are exactly the same as in Example 1. Specifically, as follows: S1. Raw material preparation and smelting: GH4169 alloy is smelted in a vacuum induction furnace (VIM). In the later stage of refining, boron carbide nucleating agent is added at a rate of 0.008% of the mass of the consumable ingot. Vacuum consumable remelting (VAR) is then carried out to produce consumable ingots with a diameter of φ508mm.

[0053] S2. Homogenization treatment: The consumable ingots are loaded into a heating furnace and heated to 1160°C at a rate of 80°C / h, and held for 38 hours; then the temperature is increased to 1190°C at a rate of 50°C / h, and held for 80 hours; after completion, the ingots are cooled to 500°C at a rate of 30°C / h before being removed from the furnace.

[0054] S3. Billet preparation: After homogenization and polishing, the consumable ingot is put back into the heating furnace and heated to 1110℃ for 6 hours.

[0055] S4. Multi-stage upsetting and drawing forging: "Two upsetting and two drawing" forging is carried out at 1110℃ (deformation amount of about 35% per heat). Then the temperature is reduced to 1070℃ and "one upsetting and one drawing" forging is carried out (deformation amount of about 30% per heat) to obtain the preliminary billet.

[0056] S5. Forming and Forging: The billet is placed in a heating furnace and heated at 1030℃ for 5 hours to allow the core temperature to drop to 1030℃. Then, it undergoes a "one-upset-one-drawing" forging process. The temperature is then lowered to 985℃, and at this temperature, it is drawn in three passes and then rounded to the target size of φ400mm. During the forging process, the anvil is baked (220℃) and the billet is insulated with a soft sleeve to control the deformation per pass within 8% to 10%.

[0057] S6. Post-treatment: After forging, the bar is air-cooled to room temperature. After machining, ultrasonic testing is performed. After the test results reach AA grade, the end 200mm of material is cut off, and φ400×20mm round samples are cut out.

[0058] S7. Sample Preparation: The circular sample is heat-treated: solution treated at 975℃ for 1.5 hours, followed by oil cooling; then aged according to standard. Metallographic and mechanical property samples are cut from the center, 1 / 2R, and edge of the heat-treated circular sample. Comparative Example 4 (Prior Art): This comparative example uses a traditional forging method without adding any nucleation refining agent, and the forging process is different: after homogenization, all upsetting and forming forging are completed directly at a high temperature (1120℃), without adopting the staged cooling forging and strict temperature control measures used in the examples.

[0059] Comparative experiment on the properties of high-temperature alloy large bars: Experimental methods: The φ400mm GH4169 bars obtained in Examples 1, 2, and 3, and Comparative Examples 1, 2, 3, and 4 are respectively designated as Sample 1, Sample 2, Sample 3, Sample D1, Sample D2, Sample D3, and Sample D4. All samples were sampled and tested for performance according to standard methods.

[0060] Detection method: (1) Average grain size and grade difference: Refer to GB / T 6394-2017 to evaluate the grain size at the core, 1 / 2R and edge of the metallographic sample, and calculate the average value and the maximum grade difference.

[0061] (2) High-temperature creep performance at 650℃: Refer to GB / T 2039-2012 to test the creep fracture time and elongation after fracture of transverse specimens under stress of 650℃ / 690MPa.

[0062] Ultrasonic flaw detection: Perform the following steps: The bars prepared in each embodiment and comparative example were precision machined to ensure a smooth surface free of iron filings, oil, oxide scale, and other impurities. The surface roughness (Ra) was 2.8 μm. Then, using a longitudinal wave straight probe and a GH4169 control block with artificial flat-bottom holes (φ0.8 mm / φ1.2 mm), the instrument was calibrated on the control block, and the reflected wave from the flat-bottom holes was adjusted to 80% of the full screen height to establish the "reference sensitivity".

[0063] Perform a 100% scan on the outer surface of the bar. Use a spiral path and ensure that adjacent scan lines have 15% to 20% overlap, performing scans in five mutually perpendicular directions.

[0064] During the entire inspection process, no defect signal exceeding the reference wave height of the φ0.8mm / φ1.2mm flat-bottom hole is allowed. If this condition is met, it is judged as "AA grade qualified" / "A grade qualified".

[0065] The test results are shown in Table 1.

[0066] Table 1. Comparison of Grain Size and Creep Performance Test Results for High-Temperature Alloy Bars

[0067] Note: In Table 1, a higher average grain size level number indicates finer grains; a lower grain size difference level number indicates a more uniform microstructure, more stable performance, and higher reliability.

[0068] The comparison of the test results of samples 1, 2, 3, D1 and D4 in Table 1 shows that the bars prepared by the method of the present invention (Examples 1 to 3) have significantly better average grain size, microstructure uniformity, high temperature creep performance and flaw detection grade than Comparative Example 1 without additives and Comparative Example 4 using traditional process.

[0069] As can be seen from the test results of samples 1, D2, and D3 in Table 1, although the addition of yttrium oxide or boron carbide alone has a certain improvement effect on the average grain size and grain size difference, the combined addition of the two in Example 1 shows a significant synergistic effect: under the premise that the amount of nucleating refiner used is exactly the same, the combined addition in Example 1 is far superior to the effect of using either alone in terms of grain refinement, microstructure uniformity (grain size difference), and high-temperature creep performance. This indicates that yttrium oxide and boron carbide in the composite nucleating refiner of the present invention have a significant synergistic effect in promoting ultra-fine graining and high uniformity of the cross-section of high-temperature alloy large bars. The inventor believes that this is related to the fact that the two can synergistically suppress the occurrence of "abnormal grain growth" (secondary recrystallization), so that even in the complex forging process of multiple heating cycles and temperature changes, the grains of the entire bar cross-section (from the surface to the core) can remain uniform and fine, thereby controlling the grain size difference at an extremely low level.

Claims

1. A method of forging a super-fine-grained gas turbine engine high-temperature alloy bar stock, characterized by, It comprises the following steps: Step A: homogenizing treatment is performed on the consumable ingot made by vacuum induction smelting and vacuum consumable remelting; wherein, a composite nucleation refiner is added during the vacuum induction smelting process, and the composite nucleation refiner is added in an amount of 0.001% to 0.015% of the mass of the consumable ingot; the composite nucleation refiner is composed of yttrium oxide and boron carbide in a mass ratio of 1:0.2 to 0.7; Step B: the consumable ingot after the homogenizing treatment is reheated to a forging temperature and kept for a period of time; Step C: the heated alloy ingot is first subjected to high-temperature upsetting and drawing forging, and then subjected to medium-temperature upsetting and drawing forging after cooling; Step D: the forged alloy blank is subjected to low-temperature upsetting, and then subjected to multi-fire lengthening forming and drop round forging after cooling; Step E: the formed alloy bar is air-cooled to room temperature, and is subjected to flaw detection and sampling; Step F: the sampling sample is subjected to heat treatment and metallographic structure and performance detection.

2. The forging method according to claim 1, characterized by, In step A, the homogenizing treatment is: the consumable ingot is heated to 1150 to 1170℃, the holding time is > 30h, then it is heated to 1180 to 1200℃, the holding time is > 72h, and after completion, it is subjected to furnace cooling.

3. The forging method according to claim 1, characterized by, In step B, the reheating is: the finished consumable ingot is heated to 1100 to 1120℃, and kept uniform for more than 4h.

4. The forging method according to claim 1, characterized by, In step C, the high-temperature upsetting and drawing forging is two upsetting and two drawing at 1100 to 1120℃; the medium-temperature upsetting and drawing forging is one upsetting and one drawing at 1040 to 1090℃ after cooling.

5. The forging method of claim 1 wherein, In step D, the low-temperature upsetting is: the blank is kept uniform at 1010 to 1040℃, so that the core temperature is reduced to 1010 to 1040℃, and after keeping for more than 3h, one upsetting and one drawing is performed; the multi-fire lengthening forming and drop round forging is performed at 980 to 990℃ after cooling, and during the forging process, the measures of tooling baking and soft packing are adopted.

6. The forging method of claim 1, wherein In step E, the flaw detection is AA-level ultrasonic flaw detection on the finished bar; the sampling is: after cutting off the head and tail material of 150 to 250mm at the end of the bar, a round sample is cut.

7. The forging method of claim 1 wherein, In step F, the heat treatment is solid solution and aging treatment on the round sample; the solid solution treatment condition is 950 to 980℃ for 1 to 2h.

8. The forging method of claim 1, wherein The high-temperature alloy is GH4169 alloy.

9. A super-fine-grained high-temperature alloy large bar for aero-engines prepared by the forging method of any one of claims 1 to 8.

10. A method of producing a gas turbine turbine disk member, characterized by: The raw material comprises the super-fine-grained high-temperature alloy large bar for aero-engines of claim 9. The raw material comprises the super-fine-grained high-temperature alloy large bar for aero-engines of claim 9.

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