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

Abstract

The invention belongs to the technical field of non-ferrous metal processing, and particularly discloses a large-size GH4586 high-temperature alloy forged bar billet and a preparation method thereof.The preparation method comprises the steps that (1) a three-vacuum process is adopted for smelting, so that a cast ingot with components meeting the standard requirement and without macrosegregation is obtained, and the problem of the white spot defect is effectively avoided; (2) carrying out high-temperature homogenization treatment on the cast ingot in a stepped temperature rise heating mode so as to reduce thermal stress, eliminate a low-melting-point phase and relieve microscopic segregation; and (3) finally, the cast ingot is subjected to forging of 8-15 heating numbers, and during forging, a deformation mode that upsetting and drawing are combined under the step-by-step cooling condition is adopted, so that an as-cast structure is fully broken. According to the preparation method, the GH4586 high-temperature alloy bar billet with the diameter of phi 300-phi 400 mm can be prepared, actual tests show that the grain size is above level 5, and meanwhile, the GH4586 high-temperature alloy bar billet has excellent strength and plasticity and completely meets the requirements of the aerospace field for various properties of the GH4586 high-temperature alloy bar billet.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing, and in particular relates to a large-size GH4586 high-temperature alloy forging bar blank and a preparation method thereof. Background Art

[0002] In modern high-end manufacturing, especially in the aerospace field, the demand for high-performance materials is extremely urgent. As an important Ni-Cr-Co series deformation high-temperature alloy, GH4586 high-temperature alloy obtains good solid solution strengthening effect by adding 12% cobalt, 9% molybdenum and 4% tungsten, while the addition of 1.7% aluminum and 3.5% titanium brings about aging strengthening effect. This makes GH4586 high-temperature alloy have excellent properties such as good tensile strength, long-term creep, oxidation resistance and corrosion resistance in the range of -192℃~850℃, thus becoming a material that has attracted much attention in high-end manufacturing fields such as aerospace.

[0003] However, there are two main problems in the preparation of large-size billets of GH4586 high-temperature alloy: on the one hand, the GH4586 high-temperature alloy has a high degree of alloying and the volume fraction of the strengthening phase γ' exceeds 20%, which leads to high thermal deformation resistance and a narrow forging temperature range, and cracking is very likely to occur during the forging process. In addition, there are MC, M6C and M 23 For C6 carbides, the hot working parameters have a significant impact on the morphology, grain size and mechanical properties of these carbides, and poor plasticity often occurs due to uneven or unqualified grain size. On the other hand, from the perspective of existing high-temperature alloy billet preparation technology, there are the following problems: in the smelting process, the traditional double-melting process is prone to white spot defects, which seriously damages the quality of the ingot and threatens the performance stability of the subsequent processed products; in addition, there is currently a lack of effective methods for the homogenization of the ingot, resulting in the inability to properly solve the problem of internal component segregation of the ingot, and the microstructure is not ideal, which causes difficulties for the subsequent forging process; in addition, during the forging process, unreasonable process parameters and methods cannot fully tap the performance potential of the material, and it is difficult to ensure that the billet meets the strict requirements of the aerospace field for high-performance materials in terms of key performance indicators such as organizational uniformity, strength and plasticity. The above problems jointly restrict the further extensive application and development of GH4586 high-temperature alloy in the field of high-end manufacturing.

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

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a large-size GH4586 high-temperature alloy forging bar blank and a preparation method thereof, which are mainly used to solve the following two problems: one is the large thermal deformation resistance, narrow forging temperature, easy cracking, grain size and plasticity problems caused by the characteristics of GH4586 high-temperature alloy itself; the other is the problem that the existing preparation technology cannot meet the high performance requirements of aerospace due to white spots in smelting, poor ingot homogenization and unreasonable forging parameters.

[0006] The purpose of the present invention is to be solved by the following technical solutions:

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

[0008] Step 1: adopting the "three vacuum" smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting to melt in sequence to prepare a GH4586 high temperature alloy ingot with a diameter between Φ490 mm and Φ610 mm;

[0009] Step 2: using a natural gas furnace to perform high temperature homogenization treatment on the GH4586 high temperature alloy ingot obtained in step 1 to promote full diffusion of various elements;

[0010] Step 3: Use an 80MN fast forging machine to continuously re-forge the GH4586 high-temperature alloy ingot after high-temperature homogenization treatment in step 2 for 8 to 15 times, and strictly control the forging parameters during the entire forging process. After forging, air cool it, then peel and saw it, and finally obtain the target GH4586 high-temperature alloy forging bar blank.

[0011] Furthermore, in step 2, the high temperature homogenization treatment adopts a step-by-step heating method to heat the GH4586 high temperature alloy ingot.

[0012] Furthermore, the high temperature homogenization treatment is carried out in the following four consecutive stages, and the specific process is as follows:

[0013] The first stage: heating the GH4586 high temperature alloy ingot to a temperature of 750°C to 850°C, and the holding time is 120min to 360min;

[0014] The second stage: after the first stage, the GH4586 high temperature alloy ingot is heated to a temperature of 990°C to 1040°C, and the holding time is 180min to 400min;

[0015] The third stage: after the second stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1130°C to 1170°C, and the holding time is 2000min to 2500min;

[0016] The fourth stage: After the third stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1170°C to 1200°C, the insulation time is 3000min to 3500min, and then air-cooled.

[0017] Furthermore, the heating rate during the temperature increase from the first stage to the second stage, from the second stage to the third stage, and from the third stage to the fourth stage is 3° C. / min to 8° C. / min.

[0018] Furthermore, in step three, when the GH4586 high-temperature alloy ingot is subjected to 8 to 15 times of continuous re-forging, a deformation method combining upsetting and drawing under step-by-step cooling conditions is first adopted to improve the uniformity of the structure, and finally the target GH4586 high-temperature alloy forging bar blank is obtained by rounding.

[0019] Furthermore, when the GH4586 high-temperature alloy ingot is subjected to 8 to 15 consecutive re-forgings, the forging temperature for the first 4 to 6 fires is set to 1140°C to 1170°C, and the deformation for each fire is 20% to 40%; the forging temperature for the remaining fires is set to 1050°C to 1120°C, and the deformation for each fire is 5% to 50%.

[0020] Preferably, except for the rounding and shaping in the last fire, the last few forging fires in the low temperature stage adopt large deformation, and the deformation amount is 41% to 49%.

[0021] In a second aspect, the present invention provides a large-size GH4586 high-temperature alloy forging bar blank, which is prepared according to the above-mentioned preparation method. The diameter of the GH4586 high-temperature alloy forging bar blank 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 rod blank are as follows: room temperature tensile strength ≥1400MPa, room temperature tensile yield strength ≥940MPa, room temperature tensile elongation ≥20%, 800°C high temperature tensile strength ≥930MPa, 800°C high temperature tensile yield strength ≥795MPa, 800°C high temperature tensile elongation ≥17%.

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

[0024] The method for preparing GH4586 high-temperature alloy forging bar blank provided by the present invention comprises the following steps: firstly, in the smelting step, a "three-vacuum" smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting is used to sequentially melt the GH4586 high-temperature alloy, thereby effectively avoiding the problem of white spot defects that are prone to occur in the traditional vacuum induction melting + vacuum consumable remelting "double-link" and vacuum induction melting + electroslag remelting + vacuum consumable remelting "triple-link" smelting processes, and the quality of the obtained ingot is better; secondly, a step-type high-temperature homogenization process is used for the treatment of the ingot to promote the full diffusion of various elements. It can effectively eliminate the component segregation produced during the solidification process of the ingot, optimize the microstructure, and provide good organizational conditions for the subsequent forging process; finally, in the forging stage, a combination of upsetting and drawing under step-by-step cooling is adopted to fully break up the cast structure in the high temperature stage and improve the plasticity. In the relatively low temperature stage (except for the last rounding and shaping), the deformation amount of each fire is increased to make the structure fully recrystallize, achieve grain refinement, and improve the uniformity of the structure, thus solving the problems of high thermal deformation resistance, narrow forging temperature, easy cracking, grain size and plasticity caused by the characteristics of GH4586 high-temperature alloy. After actual testing, the grain size of the rod blank obtained by the preparation method of the present invention can reach level 5 or finer, and at the same time, the mechanical properties are excellent, the room temperature tensile strength is ≥1400MPa, the room temperature tensile yield strength is ≥940MPa, the room temperature tensile elongation is ≥20%, the 800℃ high temperature tensile strength is ≥930MPa, the 800℃ high temperature tensile yield strength is ≥795MPa, and the 800℃ high temperature tensile elongation is ≥17%, which fully meets the strict requirements of the aerospace field for the uniform organization, high strength and good plasticity of the GH4586 alloy forging rod blank. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a flow chart of the method for preparing large-size GH4586 high-temperature alloy forging bar blank of the present invention;

[0028] Figure 2 This is a physical picture of a GH4586 alloy bar blank with a specification of Φ300 mm prepared in Example 1 of the present invention;

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

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

[0031] Figure 5 This is a physical picture of the GH4586 alloy bar blank with a specification of Φ350 mm prepared in Example 2 of the present invention;

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

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

[0034] Figure 8 This is a physical picture of a GH4586 alloy bar blank with a specification of Φ400 mm prepared in Example 3 of the present invention;

[0035] Fig. 9 is a microstructure diagram of the head of the GH4586 alloy billet prepared in Example 3 of the present invention;

[0036] Fig.10 This is a microstructure diagram of the tail of the GH4586 alloy rod blank prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0037] Here, exemplary embodiments will be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention as detailed in the appended claims.

[0038] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0039] like Figure 1 As shown, the present invention provides a method for preparing a large-size GH4586 high-temperature alloy forging bar billet, comprising the following steps:

[0040] Step 1: adopting the "three vacuum" smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting to melt in sequence to prepare GH4586 high-temperature alloy ingots with a diameter between Φ490 mm and Φ610 mm. This step effectively avoids the risk of white spot defects that are prone to occur in the double process;

[0041] Step 2: using a natural gas furnace to perform high temperature homogenization treatment on the GH4586 high temperature alloy ingot obtained in step 1 to promote full diffusion of various elements;

[0042] Step 3: Use an 80MN fast forging machine to continuously re-forge the GH4586 high-temperature alloy ingot after high-temperature homogenization treatment in step 2 for 8 to 15 times, and strictly control the forging parameters during the entire forging process. After forging, air cool it, then peel and saw it, and finally obtain the target GH4586 high-temperature alloy forging bar blank.

[0043] Specifically, in step 2, the present invention adopts a step-by-step heating method to heat the GH4586 high-temperature alloy ingot during high-temperature homogenization treatment. The specific process is carried out in the following four consecutive stages: the first stage: heating the GH4586 high-temperature alloy ingot to a temperature of 750°C to 850°C, and the holding time is 120min to 360min; the second stage: after the first stage, heating the GH4586 high-temperature alloy ingot to a temperature of 990°C to 1040°C, and the holding time is 180min to 40 0min; the third stage: after the second stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1130℃~1170℃, and the holding time is 2000min~2500min; the fourth stage: after the third stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1170℃~1200℃, and the holding time is 3000min~3500min, and air cooling is performed after the holding is completed. The purpose of this step is to reduce the internal thermal stress of the ingot, eliminate the low melting point phase, and reduce microsegregation. Preferably, the heating rate during the heating from the first stage to the second stage, from the second stage to the third stage, and from the third stage to the fourth stage is 3℃ / min~8℃ / min.

[0044] In step 3, when the GH4586 high-temperature alloy ingot is continuously forged for 8 to 15 times, a deformation method combining upsetting and drawing under step-by-step cooling conditions is first used to improve the uniformity of the structure, and finally the target GH4586 high-temperature alloy forged bar blank is obtained by rounding and shaping. Among them, the forging temperature is set to 1140℃~1170℃ for the first 4 to 6 times, and the deformation amount of each fire is 20%~40%; the forging temperature of the remaining fires is set to 1050℃~1120℃, and the deformation amount of each fire is 5%~50%. It should be noted that in the last few times of the relatively low temperature stage (except for the rounding and shaping of the last fire), the deformation amount of each fire is increased to 41%~49%, so that the structure is fully recrystallized, the grains are refined, and the uniformity of the structure is improved. The purpose of this step is to fully break the as-cast structure and obtain a uniform bar blank.

[0045] The preparation method of the present invention mainly improves the uniformity of the rod blank structure through multi-stage step-type GH4586 high-temperature homogenization and step-by-step cooling forging, as well as a deformation mode combining upsetting and drawing, thereby avoiding the occurrence of coarse grains or mixed grains, and through low-temperature large deformation, the structure undergoes sufficient dynamic recrystallization, obtains a uniform fine-grained structure, and greatly improves the mechanical properties of the rod blank.

[0046] In the above preparation method, the preparation method further comprises the following steps:

[0047] Performance heat treatment and testing: Samples of forged billets are taken, and after solution treatment and aging treatment, the organization and performance tests are carried out. The solution treatment process is: 1080℃ for 4 hours, air cooling; the aging treatment process is: 760℃ for 16 hours, air cooling.

[0048] In order to further verify the efficacy 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 specification of Φ300 mm)

[0050] The purpose of the embodiment of the present invention is to prepare a GH4586 high-temperature alloy bar with a diameter of Φ300 mm. The specific preparation process is as follows:

[0051] 1) The “three vacuum” smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting is used in sequence to melt, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508 mm is 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 full diffusion of various elements. The specific process is divided into the following four consecutive stages:

[0053] The first stage: heat the GH4586 high temperature alloy ingot to 750℃ and keep it warm for 360min;

[0054] The second stage: After the first stage, the GH4586 high temperature alloy ingot was heated to 990°C at a heating rate of 3°C / min and kept at this temperature for 400min;

[0055] Stage 3: After the second stage, the GH4586 high temperature alloy ingot was heated to 1130°C at a heating rate of 5°C / min and kept warm for 2500min;

[0056] Stage 4: After the third stage, the GH4586 high-temperature alloy ingot was heated to 1170°C at a heating rate of 6°C / min, kept warm for 3500 minutes, and then air-cooled.

[0057] 3) Using an 80MN fast forging machine, the GH4586 high temperature alloy ingot after high temperature homogenization treatment in step 3) is continuously forged for 8 times, wherein the forging temperature of the first 4 times is 1170°C, the forging temperature of the 5th to 6th times is 1120°C, and the forging temperature of the 7th to 8th times is 1100°C. The specific forging process parameters are shown in Table 1 below:

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

[0059] Fire Deformation temperature / ℃ Deformation method Deformation Material size / mm 1 1170 Upsetting + drawing Upsetting: 21%, Drawing: 25% Bafang 480 2 1170 Upsetting + drawing Upsetting: 32%, Drawing: 34% Bafang 470 3 1170 Upsetting + drawing Upsetting: 36%, Drawing: 36% Bafang 470 4 1170 Upsetting + drawing Upsetting: 36%, Drawing: 36% Bafang 470 5 1120 Upsetting + drawing Upsetting: 36%, Drawing: 36% Bafang 470 6 1120 Upsetting + drawing Upsetting: 21%, Drawing: 40% Bafang 410 7 1100 Pull out Pull length: 46% Bafang 300 8 1100 Wrestling Round: 5% Φ300

[0060] During the whole forging process, the forging parameters are strictly controlled. After forging, the forging is air-cooled, followed by peeling and sawing. Finally, the GH4586 high-temperature alloy billet with a specification of Φ300mm is obtained. Figure 2 shown.

[0061] In order to further verify the effect 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 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 The mechanical properties test results are shown in Table 2 below:

[0062] Table 2: Mechanical properties test results of GH4586 high temperature alloy billet in Example 1

[0063]

[0064]

[0065] Example 2 (Preparation of GH4586 high temperature alloy billet with a specification of Φ350 mm)

[0066] The purpose of the embodiment of the present invention is to prepare a GH4586 high-temperature alloy bar with a diameter of Φ350 mm. The specific preparation process is as follows:

[0067] 1) The “three vacuum” smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting is used in sequence to melt, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508 mm is 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 full diffusion of various elements. The specific process is divided into the following four consecutive stages:

[0069] The first stage: heat the GH4586 high temperature alloy ingot to 800℃ and keep it warm for 240min;

[0070] The second stage: After the first stage, the GH4586 high temperature alloy ingot was heated to 1020°C at a heating rate of 8°C / min and kept warm for 300 minutes;

[0071] Stage 3: After the second stage, the GH4586 high temperature alloy ingot was heated to 1150°C at a heating rate of 7°C / min and kept at this temperature for 2300min;

[0072] Stage 4: After the third stage, the GH4586 high-temperature alloy ingot was heated to 1180°C at a heating rate of 6°C / min, kept warm for 3200 minutes, and then air-cooled.

[0073] 3) Using an 80MN fast forging machine, the GH4586 high temperature alloy ingot after high temperature homogenization treatment in step 3) is continuously forged for 13 times, wherein the forging temperature of the first 6 times is 1140°C, and the forging temperature of the subsequent 7 times is 1050°C. The specific forging process parameters are shown in Table 3 below:

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

[0075] Fire Deformation temperature / ℃ Deformation method Deformation Material size / mm 1 1140 Upsetting + drawing Upsetting: 21%, Drawing: 25% Bafang 480 2 1140 Upsetting + drawing Upsetting: 24%, Drawing: 27% Bafang 470 3 1140 Upsetting + drawing Upsetting: 27%, Drawing: 27% Bafang 470 4 1140 Upsetting + drawing Upsetting: 29%, Drawing: 29% Bafang 470 5 1140 Upsetting + drawing Upsetting: 32%, Drawing: 32% Bafang 470 6 1140 Upsetting + drawing Upsetting: 32%, Drawing: 32% Bafang 470 7 1050 Upsetting + drawing Upsetting: 34%, Drawing: 34% Bafang 470 8 1050 Upsetting + drawing Upsetting: 36%, Drawing: 26% Bafang 470 9 1050 Upsetting + drawing Upsetting: 38%, Drawing: 38% Bafang 470 10 1050 Upsetting Upsetting: 44% Bafang 630 11 1050 Pull out Pull length: 47% Bafang 460 12 1050 Pull out Pull length: 42% Bafang 350 13 1050 Wrestling Round: 5% Φ350

[0076] During the whole forging process, the forging parameters are strictly controlled. After forging, the forging is air-cooled, followed by peeling and sawing. Finally, the GH4586 high-temperature alloy billet with a specification of Φ350mm is obtained. Figure 5 shown.

[0077] In order to further verify the effect 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 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 The mechanical properties test results are shown in Table 4 below:

[0078] Table 4: Mechanical properties test results 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 Φ400 mm)

[0082] The purpose of the embodiment of the present invention is to prepare a GH4586 high-temperature alloy bar with a diameter of Φ400 mm. The specific preparation process is as follows:

[0083] 1) The “three vacuum” smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting is used in sequence to melt, and finally a GH4586 high temperature alloy ingot with a diameter of Φ508 mm is 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 full diffusion of various elements. The specific process is divided into the following four consecutive stages:

[0085] The first stage: heat the GH4586 high temperature alloy ingot to 850℃ and keep it warm for 120min;

[0086] The second stage: After the first stage, the GH4586 high temperature alloy ingot was heated to 1040°C at a heating rate of 3°C / min and kept warm for 180 minutes;

[0087] Stage 3: After the second stage, the GH4586 high temperature alloy ingot was heated to 1170°C at a heating rate of 5°C / min and kept warm for 2000min;

[0088] Stage 4: After the third stage, the GH4586 high-temperature alloy ingot was heated to 1200°C at a heating rate of 4°C / min, kept warm for 3000 minutes, and then air-cooled.

[0089] 3) Using an 80MN fast forging machine, the GH4586 high temperature alloy ingot after the high temperature homogenization treatment in step 3) is continuously forged for 15 times, wherein the forging temperature of the first 6 times is 1155°C, the forging temperature of the 7th to 8th times is 1120°C, the forging temperature of the 9th to 11th times is 1080°C, and the forging temperature of the 12th to 15th times is 1060°C. 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 + drawing Upsetting: 20%, Drawing: 22% Bafang 490 2 1155 Upsetting + drawing Upsetting: 23%, Drawing: 23% Bafang 490 3 1155 Upsetting + drawing Upsetting: 28%, Drawing: 28% Bafang 490 4 1155 Upsetting + drawing Upsetting: 31%, Drawing: 31% Bafang 490 5 1155 Upsetting + drawing Upsetting: 31%, Drawing: 31% Bafang 490 6 1155 Upsetting + drawing Upsetting: 31%, Drawing: 31% Bafang 490 7 1120 Upsetting + drawing Upsetting: 33%, Drawing: 33% Bafang 490 8 1120 Upsetting + drawing Upsetting: 33%, Drawing: 33% Bafang 490 9 1080 Upsetting + drawing Upsetting: 35%, Drawing: 35% Bafang 490 10 1080 Upsetting + drawing Upsetting: 39%, Drawing: 39% Bafang 490 11 1080 Upsetting + drawing Upsetting: 39%, Drawing: 39% Bafang 490 12 1060 Upsetting Upsetting: 49% Bafang 690 13 1060 Pull out Pull length: 41% Bafang 530 14 1060 Pull out Pull length: 43% Bafang 400 15 1060 Wrestling Round: 5% Φ400

[0092] During the whole forging process, the forging parameters are strictly controlled. After forging, it is air-cooled, and then peeled and sawed to finally obtain the GH4586 high-temperature alloy billet with a specification of Φ400mm. Figure 8 shown.

[0093] In order to further verify the effect 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 sizes of the head and tail of the GH4586 high-temperature alloy billet were rated as 5 and 5.5 according to ASTM E 112. Fig. 9 , 10The mechanical properties test results are shown in Table 6 below:

[0094] Table 6: Mechanical properties test results of Example 3-GH4586 high temperature alloy billet

[0095]

[0096] In summary, through the above actual measurement and verification of the grain size and various mechanical properties of the prepared GH4586 high-temperature alloy bar blanks of different specifications, it is sufficient to illustrate that the GH4586 high-temperature alloy bar blank prepared by the preparation method of the present invention has uniform structure, high strength and good plasticity, and its grain size reaches 5 or above according to ASTM E 112 rating, and the 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, 800℃ high temperature tensile elongation ≥17%, which fully meets the requirements of the aerospace field for its various performances.

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

[0098] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may 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 a large-size GH4586 high-temperature alloy forging bar billet, characterized in that: The following steps are involved: Step 1: adopting the "three vacuum" smelting process of vacuum induction melting + vacuum consumable remelting + vacuum consumable remelting to melt in sequence to prepare GH4586 high temperature alloy ingots with a diameter between Φ490 mm and Φ610 mm; Step 2: using a natural gas furnace to perform high temperature homogenization treatment on the GH4586 high temperature alloy ingot obtained in step 1 to promote full diffusion of various elements; Step 3: Use an 80MN fast forging machine to forge the GH4586 high-temperature alloy ingot after high-temperature homogenization treatment in step 2 for 8 to 15 times, and strictly control the forging parameters during the entire forging process. After forging, air cool it, then peel and saw it, and finally obtain the target GH4586 high-temperature alloy forging bar blank.

2. The method for preparing large-size GH4586 high-temperature alloy forging bar billet according to claim 1, characterized in that: In step 2, the high temperature homogenization treatment adopts step-by-step heating of the GH4586 high temperature alloy ingot.

3. The method for preparing large-size GH4586 high-temperature alloy forging bar billet according to claim 2, characterized in that: The high temperature homogenization treatment is carried out in the following four consecutive stages, and the specific process is as follows: The first stage: heating the GH4586 high temperature alloy ingot to a temperature of 750°C to 850°C, and the holding time is 120min to 360min; The second stage: after the first stage, the GH4586 high temperature alloy ingot is heated to a temperature of 990°C to 1040°C, and the holding time is 180min to 400min; The third stage: after the second stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1130°C to 1170°C, and the holding time is 2000min to 2500min; The fourth stage: After the third stage, the GH4586 high temperature alloy ingot is heated to a temperature of 1170°C to 1200°C, the insulation time is 3000min to 3500min, and then air-cooled.

4. The method for preparing large-size GH4586 high-temperature alloy forging bar billet according to claim 3 is characterized in that: The heating rates when the temperature is increased from the first stage to the second stage, from the second stage to the third stage, and from the third stage to the fourth stage are 3° C. / min to 8° C. / min.

5. The method for preparing large-size GH4586 high-temperature alloy forging bar billet according to claim 1, characterized in that: In step three, when the GH4586 high-temperature alloy ingot is forged for 8 to 15 times, a deformation method combining upsetting and drawing under step-by-step cooling conditions is first adopted to improve the uniformity of the structure, and finally the target GH4586 high-temperature alloy forging bar blank is obtained by rounding.

6. The method for preparing large-size GH4586 high-temperature alloy forging bar billet according to claim 5, characterized in that: In step three, when the GH4586 high-temperature alloy ingot is continuously re-forged for 8 to 15 times, the forging temperature for the first 4 to 6 times is set to 1140°C to 1170°C, and the deformation for each time is 20% to 40%; the forging temperature for the remaining times is set to 1050°C to 1120°C, and the deformation for each time is 5% to 50%.

7. A large-size GH4586 high-temperature alloy forging bar billet, characterized in that: The GH4586 high-temperature alloy forging bar blank is prepared according to the preparation method described in any one of claims 1 to 6. The diameter of the GH4586 high-temperature alloy forging bar blank is Φ300mm-Φ400mm, and the grain size reaches level 5 or above according to ASTM E 112 rating.

8. The large-size GH4586 high-temperature alloy forging bar blank according to claim 7 is characterized in that: The mechanical properties of the GH4586 high-temperature alloy forged rod blank are as follows: room temperature tensile strength ≥1400MPa, room temperature tensile yield strength ≥940MPa, room temperature tensile elongation ≥20%, 800°C high temperature tensile strength ≥930MPa, 800°C high temperature tensile yield strength ≥795MPa, 800°C high temperature tensile elongation ≥17%.

Images