Large-size GH4586 high-temperature alloy forged bar and preparation method thereof

Abstract

The application belongs to the technical field of non-ferrous metal processing, and particularly discloses a large-size GH4586 high-temperature alloy forged bar and a preparation method thereof, which comprises the following steps: 1) a three-vacuum process is adopted to smelt a casting ingot with components meeting the standard requirements and without macrosegregation, so as to effectively avoid the white spot defect; 2) a stepwise heating mode is used to perform high-temperature homogenization treatment on the casting ingot, so as to reduce thermal stress, eliminate low-melting-point phases and reduce microsegregation; and 3) finally, the casting ingot is forged for 8-15 fire times, and a deformation mode of upsetting combined with elongation is adopted under the condition of step-by-step temperature reduction, so as to fully break the as-cast structure. According to the preparation method, the GH4586 high-temperature alloy bar with a diameter of Φ300-Φ400mm can be prepared, and through actual test, the grain size is above 5, the alloy has excellent strength and plasticity, and fully meets the requirements of the aerospace field on various performances.

Description

Technical Field

[0001] This invention belongs to the field of non-ferrous metal processing technology, specifically relating to a large-size GH4586 high-temperature alloy forged billet and its preparation method. Background Technology

[0002] In modern high-end manufacturing, especially in the aerospace field, the demand for high-performance materials is extremely urgent. GH4586 superalloy, as an important Ni-Cr-Co wrought superalloy, achieves excellent solid solution strengthening through the addition of 12% cobalt, 9% molybdenum, and 4% tungsten, while the addition of 1.7% aluminum and 3.5% titanium brings age-hardening effects. This gives GH4586 superalloy excellent tensile strength, creep resistance, oxidation resistance, and corrosion resistance within the temperature range of -192℃ to 850℃, making it a material of great interest in high-end manufacturing fields such as aerospace.

[0003] However, the preparation of large-size billets of GH4586 superalloy presents two main problems: Firstly, the high degree of alloying in GH4586, with the volume fraction of the strengthening phase γ' exceeding 20%, results in high resistance to hot deformation and a narrow forging temperature range, making it highly susceptible to cracking during forging. Furthermore, the alloy contains MC, M6C, and M... 23 For C6 type carbides, hot working parameters significantly affect their morphology, grain size, and mechanical properties, often resulting in poor plasticity due to inhomogeneous or substandard grain size. On the other hand, existing high-temperature alloy billet preparation technologies present the following problems: In the melting process, traditional duplex melting is prone to white spot defects, severely damaging ingot quality and threatening the performance stability of subsequent processed products; furthermore, there is a lack of effective methods for ingot homogenization, making it impossible to properly address internal component segregation issues and resulting in an undesirable microstructure, causing difficulties for subsequent forging processes; furthermore, during forging, unreasonable process parameters and methods fail to fully exploit the material's performance potential, making it difficult to ensure that the billet meets the stringent requirements of the aerospace industry for high-performance materials in terms of microstructure uniformity, strength, and plasticity. These problems collectively restrict the further widespread application and development of GH4586 high-temperature alloy in high-end manufacturing.

[0004] In view of this, this invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a large-size GH4586 high-temperature alloy forged billet and its preparation method, mainly to solve the following two problems: First, the inherent characteristics of GH4586 high-temperature alloy result in high resistance to hot deformation, narrow forging temperature, easy cracking, and problems with grain size and plasticity; Second, the existing preparation technology suffers from problems such as white spots in melting, poor ingot homogenization, and unreasonable forging parameters, which fail to meet the high-performance requirements of aerospace.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing large-size GH4586 high-temperature alloy forged billets, comprising the following steps:

[0008] Step 1: The GH4586 high-temperature alloy ingot with a diameter between Φ490mm and Φ610mm is prepared by sequentially using a “three-vacuum” smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting.

[0009] Step 2: Use a natural gas furnace to perform high-temperature homogenization treatment on the GH4586 high-temperature alloy ingot obtained in Step 1 to promote the full diffusion of each element.

[0010] Step 3: Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after being homogenized at high temperature in Step 2, is continuously forged in the furnace 8 to 15 times. The forging parameters are strictly controlled throughout the forging process. After forging, the ingot is air-cooled and then peeled and sawn to finally obtain the target GH4586 high-temperature alloy forged billet.

[0011] Furthermore, in step two, the high-temperature homogenization treatment employs a stepped heating method to heat the GH4586 high-temperature alloy ingot.

[0012] Furthermore, the high-temperature homogenization treatment is carried out in four consecutive stages, as detailed below:

[0013] First stage: Heat the GH4586 high-temperature alloy ingot to a temperature of 750℃~850℃ and hold it for 120min~360min;

[0014] Second stage: After the first stage is completed, the GH4586 high temperature alloy ingot is heated to a temperature of 990℃~1040℃ and held for 180min~400min.

[0015] Third stage: After the second stage is completed, the GH4586 high temperature alloy ingot is heated to a temperature of 1130℃~1170℃ and held for 2000min~2500min.

[0016] Fourth stage: After the third stage, the GH4586 high-temperature alloy ingot is heated to 1170℃~1200℃ and held for 3000min~3500min. After the holding time, it is air-cooled.

[0017] Furthermore, the heating rate during the first to second stage, the second to third stage, and the third to fourth stage is 3℃ / min to 8℃ / min.

[0018] Furthermore, in step three, when the GH4586 high-temperature alloy ingot is continuously forged in the furnace 8 to 15 times, a deformation method combining upsetting and drawing under progressively decreasing temperature is first adopted to improve the uniformity of the structure. Finally, the target GH4586 high-temperature alloy forging billet is obtained by rounding and shaping.

[0019] Furthermore, when the GH4586 high-temperature alloy ingot is subjected to 8 to 15 consecutive forging cycles, the forging temperature for the first 4 to 6 cycles is set at 1140℃ to 1170℃, and the deformation per cycle is 20% to 40%; the forging temperature for the remaining cycles is set at 1050℃ to 1120℃, and the deformation per cycle is 5% to 50%.

[0020] Preferably, except for the final rounding and shaping in the last heat, the last few heats of forging in the low-temperature stage adopt large deformation, with a deformation amount of 41% to 49%.

[0021] Secondly, the present invention provides a large-size GH4586 high-temperature alloy forged billet, which is prepared according to the above-mentioned preparation method. The diameter of the GH4586 high-temperature alloy forged billet is Φ300mm~Φ400mm, and the grain size reaches level 5 or above according to ASTM E 112 rating.

[0022] Furthermore, the mechanical properties of the GH4586 high-temperature alloy forged bar billet are as follows: room temperature tensile strength ≥1400MPa, room temperature tensile yield strength ≥940MPa, room temperature tensile elongation ≥20%, 800℃ high-temperature tensile strength ≥930MPa, 800℃ high-temperature tensile yield strength ≥795MPa, and 800℃ high-temperature tensile elongation ≥17%.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a method for preparing GH4586 high-temperature alloy forging billets. First, in the melting stage, a "triple vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting is used to melt the GH4586 high-temperature alloy sequentially. This effectively avoids the white spot defect problem that easily occurs in the traditional "double" smelting process of vacuum induction melting + vacuum arc remelting and the "triple" smelting process of vacuum induction melting + electroslag remelting + vacuum arc remelting, resulting in a higher quality ingot. Second, for the ingot treatment, a stepped high-temperature homogenization process is adopted to promote the full diffusion of various elements. This effectively eliminates component segregation during ingot solidification, optimizes the microstructure, and provides favorable microstructural conditions for subsequent forging processes. Finally, during the forging stage, a combination of upsetting and drawing under progressively decreasing temperatures is adopted. At high temperatures, the as-cast microstructure is fully broken down to improve plasticity. At relatively low temperatures (except for the final rounding and shaping), the deformation per forging is increased to allow for full recrystallization, resulting in refined grains and improved microstructure uniformity. This solves the problems of high hot deformation resistance, narrow forging temperature, easy cracking, grain size, and plasticity of GH4586 high-temperature alloy due to its inherent characteristics. Actual testing shows that the grain size of the billet prepared by the method of this invention can reach grade 5 or finer, while exhibiting excellent mechanical properties. Its room temperature tensile strength is ≥1400MPa, room temperature tensile yield strength is ≥940MPa, room temperature tensile elongation is ≥20%, 800℃ high temperature tensile strength is ≥930MPa, 800℃ high temperature tensile yield strength is ≥795MPa, and 800℃ high temperature tensile elongation is ≥17%, fully meeting the stringent requirements of the aerospace field for GH4586 alloy forged billets with uniform microstructure, high strength, and good plasticity. Attached Figure Description

[0025] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of the method for preparing large-size GH4586 high-temperature alloy forged billets according to the present invention;

[0028] Figure 2 This is a photograph of the GH4586 alloy bar billet with a specification of Φ300mm prepared in Example 1 of the present invention;

[0029] Figure 3 This is a microstructure image of the head of the GH4586 alloy billet prepared in Example 1 of this invention;

[0030] Figure 4 This is a microstructure image of the tail portion of the GH4586 alloy billet prepared in Example 1 of this invention;

[0031] Figure 5 This is a photograph of the GH4586 alloy bar billet with a specification of Φ350mm prepared in Example 2 of the present invention;

[0032] Figure 6 This is a microstructure image of the head of the GH4586 alloy billet prepared in Example 2 of this invention;

[0033] Figure 7 This is a microstructure image of the tail portion of the GH4586 alloy billet prepared in Example 2 of this invention;

[0034] Figure 8 This is a photograph of the GH4586 alloy bar billet with a specification of Φ400mm prepared in Example 3 of the present invention;

[0035] Figure 9 This is a microstructure image of the head of the GH4586 alloy billet prepared in Example 3 of the present invention;

[0036] Figure 10 This is a microstructure diagram of the tail portion of the GH4586 alloy billet prepared in Example 3 of the present invention. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail. The embodiments described below are not representative of all embodiments consistent with this invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0038] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] like Figure 1 As shown, this invention provides a method for preparing large-size GH4586 high-temperature alloy forged billets, comprising the following steps:

[0040] Step 1: The "three vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting is used to melt in sequence to prepare GH4586 high temperature alloy ingots with diameters between Φ490mm and Φ610mm. This step effectively avoids the risk of white spot defects that are prone to occur in the double process.

[0041] Step 2: Use a natural gas furnace to perform high-temperature homogenization treatment on the GH4586 high-temperature alloy ingot obtained in Step 1 to promote the full diffusion of each element.

[0042] Step 3: Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after being homogenized at high temperature in Step 2, is continuously forged in the furnace 8 to 15 times. The forging parameters are strictly controlled throughout the forging process. After forging, the ingot is air-cooled and then peeled and sawn to finally obtain the target GH4586 high-temperature alloy forged billet.

[0043] Specifically, in step two, during the high-temperature homogenization treatment, the present invention employs a stepped heating method for the GH4586 high-temperature alloy ingot. The specific process unfolds in the following four consecutive stages: First stage: The GH4586 high-temperature alloy ingot is heated to 750℃~850℃, and held for 120min~360min; Second stage: After the first stage, the GH4586 high-temperature alloy ingot is heated to 990℃~1040℃, and held for 180min~40min. 0 min; Third stage: After the second stage, the GH4586 high-temperature alloy ingot is heated to 1130℃~1170℃ and held for 2000 min~2500 min; Fourth stage: After the third stage, the GH4586 high-temperature alloy ingot is heated to 1170℃~1200℃ and held for 3000 min~3500 min, followed by air cooling. The purpose of this step is to reduce internal thermal stress in the ingot, eliminate low-melting-point phases, and mitigate microsegregation. Preferably, the heating rate during the first to second stage, the second to third stage, and the third to fourth stage is 3℃ / min~8℃ / min.

[0044] In step three, during the continuous remelting of the GH4586 high-temperature alloy ingot through 8-15 heats, a deformation method combining upsetting and drawing under progressively decreasing temperatures is first employed to improve microstructure uniformity. Finally, the target GH4586 high-temperature alloy forged billet is obtained through rounding and shaping. Specifically, for the first 4-6 heats, the forging temperature is set at 1140℃-1170℃, with a deformation of 20%-40% per heat. For the remaining heats, the forging temperature is set at 1050℃-1120℃, with a deformation of 5%-50% per heat. It should be noted that in the last few heats at relatively low temperatures (except for the final rounding and shaping), the deformation per heat is increased to 41%-49% to allow for sufficient recrystallization, refining the grains and improving microstructure uniformity. The purpose of this step is to fully break down the as-cast microstructure to obtain a billet with a uniform microstructure.

[0045] The preparation method of this invention mainly improves the uniformity of the billet structure by using multi-stage stepped GH4586 high-temperature homogenization and step-by-step cooling forging, as well as a deformation method that combines upsetting and drawing, thereby avoiding the formation of coarse or mixed grains. Furthermore, the low-temperature large deformation allows for full dynamic recrystallization of the structure, resulting in a uniform fine-grained structure and significantly improving the mechanical properties of the billet.

[0046] The above preparation method further includes the following steps:

[0047] Performance heat treatment and testing: Samples of the forged billets were taken and subjected to solution treatment and aging treatment, followed by microstructure and performance testing. The solution treatment process was: holding at 1080℃ for 4 hours, followed by air cooling; the aging treatment process was: holding at 760℃ for 16 hours, followed by air cooling.

[0048] To further verify the effectiveness of the powder metallurgy method of the present invention, the inventors conducted the following specific experiments:

[0049] Example 1 (Preparation of GH4586 high-temperature alloy billet with a diameter of 300mm)

[0050] The purpose of this invention is to prepare a GH4586 high-temperature alloy billet with a diameter of Φ300mm. The specific preparation process is as follows:

[0051] 1) The "three vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting was used to melt the alloy in sequence, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508mm was obtained.

[0052] 2) The GH4586 high-temperature alloy ingot obtained in step 1) is subjected to high-temperature homogenization treatment using a natural gas furnace to promote the full diffusion of each element. The specific process is divided into the following four continuous stages:

[0053] First stage: Heat the GH4586 high-temperature alloy ingot to 750℃ and hold for 360 minutes;

[0054] Second stage: After the first stage is completed, the GH4586 high temperature alloy ingot is heated to 990℃ at a heating rate of 3℃ / min and held for 400min.

[0055] Third stage: After the second stage is completed, the GH4586 high temperature alloy ingot is heated to 1130℃ at a heating rate of 5℃ / min and held for 2500min.

[0056] Fourth stage: After the third stage, the GH4586 high-temperature alloy ingot is heated to 1170℃ at a heating rate of 6℃ / min, held for 3500min, and then air-cooled.

[0057] 3) Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after high-temperature homogenization treatment in step 3), was continuously forged in eight passes. The forging temperature for the first four passes was 1170℃, the forging temperature for the fifth and sixth passes was 1120℃, and the forging temperature for the seventh and eighth passes was 1100℃. Specific forging process parameters are shown in Table 1 below:

[0058] Table 1: Forging process parameters for Example 1

[0059] Fire Deformation temperature / ℃ Deformation method Deformation Material size / mm 1 1170 Upsetting and drawing Upsetting: 21%, drawing: 25% 480 2 1170 Upsetting and drawing Upsetting: 32%, drawing: 34% 470 Eight Directions 3 1170 Upsetting and drawing Upsetting roughness: 36%, drawing length: 36% 470 Eight Directions 4 1170 Upsetting and drawing Upsetting roughness: 36%, drawing length: 36% 470 Eight Directions 5 1120 Upsetting and drawing Upsetting roughness: 36%, drawing length: 36% 470 Eight Directions 6 1120 Upsetting and drawing Upsetting: 21%, drawing: 40% 410 Bafang 7 1100 elongation Lengthening: 46% 300 Eight Directions 8 1100 Smash Smash round: 5% Φ300

[0060] Forging parameters were strictly controlled throughout the forging process. After forging, the billet was air-cooled, followed by peeling and sawing to obtain a GH4586 high-temperature alloy billet with a diameter of Φ300mm. The actual product is shown below. Figure 2 As shown.

[0061] To further verify the effectiveness of the preparation method of this invention, the inventors conducted grain size evaluation and mechanical property tests on the GH4586 high-temperature alloy billet obtained in Example 1. The grain size of the head and tail of the GH4586 high-temperature alloy billet was rated as grade 5 according to ASTM E 112. Figure 3 , 4 As shown in Table 2 below, the mechanical property test results are as follows:

[0062] Table 2: Test results of mechanical properties of GH4586 high-temperature alloy billet in Example 1

[0063]

[0064]

[0065] Example 2 (Preparation of GH4586 high-temperature alloy billet with a diameter of Φ350mm)

[0066] The purpose of this invention is to prepare a GH4586 high-temperature alloy billet with a diameter of Φ350mm. The specific preparation process is as follows:

[0067] 1) The "three vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting was used to melt the alloy in sequence, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508mm was obtained.

[0068] 2) The GH4586 high-temperature alloy ingot obtained in step 1) is subjected to high-temperature homogenization treatment using a natural gas furnace to promote the full diffusion of each element. The specific process is divided into the following four continuous stages:

[0069] First stage: Heat the GH4586 high-temperature alloy ingot to 800℃ and hold for 240 minutes;

[0070] Second stage: After the first stage is completed, the GH4586 high-temperature alloy ingot is heated to 1020℃ at a heating rate of 8℃ / min and held for 300min.

[0071] Third stage: After the second stage is completed, the GH4586 high temperature alloy ingot is heated to 1150℃ at a heating rate of 7℃ / min and held for 2300min.

[0072] Fourth stage: After the third stage, the GH4586 high-temperature alloy ingot is heated to 1180℃ at a heating rate of 6℃ / min, held for 3200min, and then air-cooled.

[0073] 3) Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after high-temperature homogenization treatment in step 3), was continuously forged in 13 heats. The forging temperature for the first 6 heats was 1140℃, and the forging temperature for the subsequent 7 heats was 1050℃. The specific forging process parameters are shown in Table 3 below:

[0074] Table 3: Forging process parameters for Example 2

[0075] Fire Deformation temperature / ℃ Deformation method Deformation Material size / mm 1 1140 Upsetting and drawing Upsetting: 21%, drawing: 25% 480 2 1140 Upsetting and drawing Upsetting: 24%, drawing: 27% 470 Eight Directions 3 1140 Upsetting and drawing Upsetting: 27%, drawing: 27% 470 Eight Directions 4 1140 Upsetting and drawing Upsetting roughness: 29%, drawing length: 29% 470 Eight Directions 5 1140 Upsetting and drawing Upsetting: 32%, drawing: 32% 470 Eight Directions 6 1140 Upsetting and drawing Upsetting: 32%, drawing: 32% 470 Eight Directions 7 1050 Upsetting and drawing Upsetting: 34%, drawing: 34% 470 Eight Directions 8 1050 Upsetting and drawing Upsetting: 36%, drawing: 26% 470 Eight Directions 9 1050 Upsetting and drawing Upsetting: 38%, drawing: 38% 470 Eight Directions 10 1050 Upsetting Upsetting: 44% 830 11 1050 elongation Lengthening: 47% 460 Eight Directions 12 1050 elongation Lengthening: 42% 350 Eight Directions 13 1050 Smash Smash round: 5% Φ350

[0076] Forging parameters were strictly controlled throughout the forging process. After forging, the billet was air-cooled, followed by peeling and sawing to obtain a GH4586 high-temperature alloy billet with a diameter of Φ350mm. The actual product is shown below. Figure 5 As shown.

[0077] To further verify the effectiveness of the preparation method of this invention, the inventors conducted grain size evaluation and mechanical property tests on the GH4586 high-temperature alloy billet obtained in Example 2. The grain size of the head and tail of the GH4586 high-temperature alloy billet was rated as 6.5 according to ASTM E 112. Figure 6 , 7 As shown in Table 4 below, the mechanical property test results are as follows:

[0078] Table 4: Test results of mechanical properties of GH4586 high-temperature alloy billet in Example 2

[0079]

[0080]

[0081] Example 3 (Preparation of GH4586 high-temperature alloy billet with a specification of Φ400mm)

[0082] The purpose of this invention is to prepare a GH4586 high-temperature alloy billet with a diameter of Φ400mm. The specific preparation process is as follows:

[0083] 1) The "three vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting was used to melt the alloy in sequence, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508mm was obtained.

[0084] 2) The GH4586 high-temperature alloy ingot obtained in step 1) is subjected to high-temperature homogenization treatment using a natural gas furnace to promote the full diffusion of each element. The specific process is divided into the following four continuous stages:

[0085] First stage: Heat the GH4586 high-temperature alloy ingot to 850℃ and hold for 120 minutes;

[0086] Second stage: After the first stage is completed, the GH4586 high-temperature alloy ingot is heated to 1040℃ at a heating rate of 3℃ / min and held for 180min.

[0087] Third stage: After the second stage is completed, the GH4586 high temperature alloy ingot is heated to 1170 at a heating rate of 5℃ / min and held for 2000min.

[0088] Fourth stage: After the third stage, the GH4586 high-temperature alloy ingot is heated to 1200℃ at a heating rate of 4℃ / min, held for 3000min, and then air-cooled.

[0089] 3) Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after high-temperature homogenization treatment in step 3), was continuously forged in 15 heats. The forging temperature for the first 6 heats was 1155℃, the forging temperature for the 7th and 8th heats was 1120℃, the forging temperature for the 9th and 11th heats was 1080℃, and the forging temperature for the 12th to 15th heats was 1060℃. The specific forging process parameters are shown in Table 5 below:

[0090] Table 5: Forging process parameters of Example 5

[0091] Fire Deformation temperature / ℃ Deformation method Deformation Material size / mm 1 1155 Upsetting and drawing Upsetting: 20%, drawing: 22% 490 Eight Directions 2 1155 Upsetting and drawing Upsetting roughness: 23%, drawing length: 23% 490 Bafang 3 1155 Upsetting and drawing Upsetting: 28%, drawing: 28% 490 Eight Directions 4 1155 Upsetting and drawing Upsetting: 31%, drawing: 31% 490 Eight Directions 5 1155 Upsetting and drawing Upsetting: 31%, drawing: 31% 490 Bafang 6 1155 Upsetting and drawing Upsetting: 31%, drawing: 31% 490 Eight Directions 7 1120 Upsetting and drawing Upsetting roughness: 33%, drawing length: 33% 490 Eight Directions 8 1120 Upsetting and drawing Upsetting roughness: 33%, drawing length: 33% 490 Bafang 9 1080 Upsetting and drawing Upsetting: 35%, drawing: 35% 490 Bafang 10 1080 Upsetting and drawing Upsetting roughness: 39%, drawing length: 39% 490 Eight Directions 11 1080 Upsetting and drawing Upsetting roughness: 39%, drawing length: 39% 490 Bafang 12 1060 Upsetting Upsetting: 49% 690 Eight Directions 13 1060 elongation Lengthening: 41% 830 14 1060 elongation Lengthening: 43% 400 Eight Directions 15 1060 Smash Smash round: 5% Φ400

[0092] Forging parameters were strictly controlled throughout the forging process. After forging, the billet was air-cooled, followed by peeling and sawing to obtain a GH4586 high-temperature alloy billet with a diameter of Φ400mm. The actual product is shown below. Figure 8 As shown.

[0093] To further verify the effectiveness of the preparation method of the present invention, the inventors conducted grain size evaluation and mechanical property tests on the GH4586 high-temperature alloy billet obtained in Example 3. The grain size of the head and tail of the GH4586 high-temperature alloy billet was rated as 5 and 5.5 respectively according to ASTM E 112. Figure 9 , 10As shown in Table 6 below, the mechanical property test results are as follows:

[0094] Table 6: Test results of mechanical properties of GH4586 high-temperature alloy billet in Example 3

[0095]

[0096] In summary, the above experimental verification of the grain size and various mechanical properties of the GH4586 high-temperature alloy billets of different specifications prepared by the present invention sufficiently demonstrates that the GH4586 high-temperature alloy billets prepared by the method of the present invention have uniform microstructure, high strength, and good plasticity. Their grain size reaches grade 5 or above according to ASTM E 112 rating, and their mechanical properties are as follows: room temperature tensile strength ≥1400MPa, room temperature tensile yield strength ≥940MPa, room temperature tensile elongation ≥20%, 800℃ high-temperature tensile strength ≥930MPa, 800℃ high-temperature tensile yield strength ≥795MPa, and 800℃ high-temperature tensile elongation ≥17%, which fully meets the requirements of the aerospace field for various performance characteristics.

[0097] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0098] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing large-size GH4586 high-temperature alloy forged bar billets, characterized in that, Includes the following steps: Step 1: The "three vacuum" smelting process of vacuum induction melting + vacuum arc remelting + vacuum arc remelting is used to melt in sequence to prepare GH4586 high temperature alloy ingots with diameters between Φ490mm and Φ610mm. Step 2: Use a natural gas furnace to perform high-temperature homogenization treatment on the GH4586 high-temperature alloy ingot obtained in Step 1 to promote the full diffusion of each element. Step 3: Using an 80MN high-speed forging mill, the GH4586 high-temperature alloy ingot, after being homogenized at high temperature in Step 2, is forged 8 to 15 times. The forging parameters are strictly controlled throughout the forging process. After forging, the ingot is air-cooled and then peeled and sawn to finally obtain the target GH4586 high-temperature alloy forged billet. In step two, the high-temperature homogenization treatment employs a stepped heating method for the GH4586 high-temperature alloy ingot, specifically carried out in the following four consecutive stages, as follows: First stage: Heat the GH4586 high-temperature alloy ingot to a temperature of 750℃~850℃ and hold it for 120min~360min; Second stage: After the first stage is completed, the GH4586 high temperature alloy ingot is heated to a temperature of 990℃~1040℃ and held for 180min~400min. Third stage: After the second stage, the GH4586 high-temperature alloy ingot is heated to a temperature of 1130℃~1170℃ and held for 2000min~2500min. Fourth stage: After the third stage, heat the GH4586 high-temperature alloy ingot to a temperature of 1170℃~1200℃ and hold it for 3000min~3500min. After holding, air cool it. In step three, when forging the GH4586 high-temperature alloy ingot 8-15 times, a deformation method combining upsetting and drawing under progressively decreasing temperature is first adopted to improve the uniformity of the microstructure. Finally, the target GH4586 high-temperature alloy forging billet is obtained by rounding and shaping. Specifically: When the GH4586 high-temperature alloy ingot is subjected to 8 to 15 consecutive forging cycles, the forging temperature for the first 4 to 6 cycles is set at 1140℃ to 1170℃, and the deformation per cycle is 20% to 40%; the forging temperature for the remaining cycles is set at 1050℃ to 1120℃, and the deformation per cycle is 5% to 50%.

2. The method for preparing large-size GH4586 high-temperature alloy forged billets according to claim 1, characterized in that, The heating rate during the first to second stage, the second to third stage, and the third to fourth stage is 3℃ / min to 8℃ / min.

3. A large-size GH4586 high-temperature alloy forged bar billet, characterized in that, The GH4586 high-temperature alloy forged bar billet is prepared according to the preparation method described in any one of claims 1 to 2. The diameter of the GH4586 high-temperature alloy forged bar billet is Φ300mm to Φ400mm, and the grain size reaches level 5 or above according to ASTM E 112 rating.

4. The large-size GH4586 high-temperature alloy forged billet according to claim 3, characterized in that, The mechanical properties of the GH4586 high-temperature alloy forged billet are as follows: room temperature tensile strength ≥1400MPa, room temperature tensile yield strength ≥940MPa, room temperature tensile elongation ≥20%, 800℃ high-temperature tensile strength ≥930MPa, 800℃ high-temperature tensile yield strength ≥795MPa, 800℃ high-temperature tensile elongation ≥17%.

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