Homogeneous Ti2AlNb alloy plate and preparation method thereof

Abstract

The invention relates to the technical field of Ti2AlNb alloy processing, in particular to a homogeneous Ti2AlNb alloy plate and a preparation method thereof. The preparation method comprises the following steps: (a) carrying out heat preservation treatment on a Ti2AlNb alloy ingot at 1260-1400 DEG C for 30-72 hours, and then cooling; (b) performing first upsetting deformation on the cast ingot at the temperature of 1100-1200 DEG C, and then performing second upsetting deformation at the temperature of 950-1100 DEG C to obtain a forging stock; forging the forging stock at 950-1100 DEG C to obtain a plate blank; and (c) carrying out heat preservation treatment on the plate blank at 1200-1400 DEG C for 8-48 hours, cooling, and rolling at 980-1080 DEG C. According to the method, a combined process of high-temperature homogenization treatment of the Ti2AlNb alloy cast ingot, large-deformation forging treatment and high-temperature homogenization treatment of the plate blank is adopted, the composition segregation condition of the obtained plate is remarkably improved, and the homogeneous Ti2AlNb alloy plate is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of Ti2AlNb alloy processing, in particular to a homogeneous Ti2AlNb alloy plate and a preparation method thereof. Background Art

[0002] As an intermetallic compound alloy, Ti2AlNb alloy exhibits excellent high-temperature mechanical properties due to its long-range ordered crystal structure and strong metallic bonding. It is currently a lightweight, high-temperature resistant structural material with the potential for long-term use in the temperature range of 600-750°C, or short-term use at higher temperatures. This alloy not only possesses outstanding high-temperature specific strength and modulus, but also exhibits excellent creep resistance. This combination of excellent properties makes it a highly promising structural material in the aerospace field, with significant engineering applications in improving aircraft thrust-to-weight ratios, optimizing fuel efficiency, and enhancing service performance in high-temperature environments.

[0003] Ti2AlNb alloys typically consist of two or three phases: O, B2 / β, and α2. The phase composition and content of the alloy can vary significantly due to changes in thermal processing, composition, and heat treatment regime. The composition of each phase in Ti2AlNb alloys varies significantly. Under the same thermal processing conditions, compositional segregation can significantly affect microstructural parameters such as the content and size of each phase. Changes in these microstructural parameters can significantly affect the mechanical properties of the alloy.

[0004] Ti2AlNb alloys are prone to segregation of Al and Nb solute elements during traditional melting and ingot casting processes due to the significant density and melting point differences between the constituent elements Ti, Al, and Nb, as well as the slow cooling rate of the molten pool caused by the alloy's inherently low thermal conductivity. To mitigate this segregation, the ingots are typically subjected to high-temperature homogenization treatment and multiple upsetting deformations prior to sheet rolling. However, improper control of the melting or upsetting deformation process parameters can still lead to compositional segregation in the finished sheet, causing problems such as uneven microstructure and fluctuations in mechanical properties. This instability in material properties can significantly reduce the service reliability of components, becoming a major technical bottleneck restricting their engineering applications in aerospace structural parts.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] One object of the present invention is to provide a method for preparing a homogeneous Ti2AlNb alloy plate, which significantly improves the composition uniformity and performance stability of the plate by suitable ingot homogenization treatment, combined with a suitable deformation process to obtain a slab, and then performs suitable homogenization treatment on the slab, while reducing the number of forging fires.

[0007] Another object of the present invention is to provide a homogeneous Ti2AlNb alloy plate produced by the above-mentioned preparation method. The Ti2AlNb alloy plate of the present invention has good structural uniformity and excellent mechanical properties.

[0008] In order to achieve the above-mentioned object of the present invention, the first aspect of the present invention provides a method for preparing a homogeneous Ti2AlNb alloy plate, comprising the following steps:

[0009] (a) The Ti2AlNb alloy ingot is heat-treated at 1260-1400°C for 30-72 hours and then cooled;

[0010] (b) subjecting the ingot treated in step (a) to a first upsetting deformation at 1100-1200° C., and then subjecting the ingot to a second upsetting deformation at 950-1100° C. to obtain a forging blank; and forging the forging blank at 950-1100° C. to obtain a slab;

[0011] (c) The slab is heat-treated at 1200-1400° C. for 8-48 hours, cooled, and then rolled at 980-1080° C. to obtain a homogeneous Ti2AlNb alloy plate.

[0012] In a specific embodiment of the present invention, the first upsetting deformation is performed more than 2 times. Furthermore, the first upsetting deformation has an upsetting deformation amount of 20% to 40% and an elongation deformation amount of 20% to 40%.

[0013] In a specific embodiment of the present invention, the second upsetting deformation is performed more than 2 times. Furthermore, in the second upsetting deformation, the deformation amount of upsetting is 35% to 60%, and the deformation amount of elongation is 35% to 60%.

[0014] In a specific embodiment of the present invention, the slab obtained by forging includes 2 to 4 fires, and the deformation amount of each fire is 20% to 50%. Furthermore, in step (b), the thickness of the slab is 120 to 350 mm.

[0015] In a specific embodiment of the present invention, the segregation size of the Ti2AlNb alloy ingot after the treatment in step (a) is ≤3 mm; in step (b), the segregation size of the slab is ≤1.5 mm.

[0016] In a specific embodiment of the present invention, in the heat preservation treatment of step (c), the charging temperature of the slab is 20-850° C. Further, the heating rate from 20-850° C. to 1200-1400° C. is 5-20° C. / min.

[0017] In a specific embodiment of the present invention, in step (c), the rolling comprises at least two rolling deformations, wherein the deformation of the initial rolling is 20% to 40%, and the deformation of the final rolling is 40% to 60%.

[0018] In a specific embodiment of the present invention, the thickness of the plate is 4 to 80 mm.

[0019] In a specific embodiment of the present invention, in step (b), the number of forging fires of the slab obtained from the ingot treated in step (a) is ≤ 9.

[0020] In a specific embodiment of the present invention, the preparation method further includes subjecting the homogeneous Ti2AlNb alloy plate to a solution treatment and an aging treatment. Furthermore, the solution treatment comprises maintaining the plate at 950-980°C for 1-4 hours, followed by air cooling or oil quenching; and the aging treatment comprises maintaining the plate at 760-820°C for 8-32 hours, followed by air cooling.

[0021] The second aspect of the present invention provides a homogeneous Ti2AlNb alloy plate produced by the method for producing the homogeneous Ti2AlNb alloy plate according to the first aspect of the present invention.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention adopts a combined process of high-temperature homogenization treatment of Ti2AlNb alloy ingots, large deformation forging treatment, and high-temperature homogenization treatment of slabs to significantly improve the composition segregation of the obtained plate and obtain a homogeneous Ti2AlNb alloy plate;

[0024] (2) The present invention significantly reduces the number of forging fires by adjusting the operating process of the Ti2AlNb alloy plate, reducing the number of forging fires to within 9 fires, thereby improving material utilization and shortening the production cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 The electron probe analysis results of the homogeneous Ti2AlNb alloy plate provided in Example 1 of the present invention;

[0027] Figure 2 The electron probe analysis results of the Ti2AlNb alloy plate provided for Comparative Example 1. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0029] Currently, the main method to improve the composition segregation problem of Ti2AlNb alloy sheets is through a combined process of deformation and high-temperature homogenization. However, current research mainly focuses on improving the ingot forging process, which requires nearly 20 forging cycles at multiple temperatures to obtain slabs. Excessive forging cycles results in significant material loss and a long production cycle. The present invention utilizes a combined process of high-temperature homogenization treatment of Ti2AlNb alloy ingots, large-deformation forging treatment, and high-temperature homogenization treatment of slabs to significantly improve the composition segregation of the obtained sheet, obtain homogenous Ti2AlNb alloy sheets, and significantly reduce the number of forging cycles.

[0030] A first aspect of the present invention provides a method for preparing a homogeneous Ti2AlNb alloy plate, comprising the following steps:

[0031] (a) The Ti2AlNb alloy ingot is heat-treated at 1260-1400°C for 30-72 hours and then cooled;

[0032] (b) subjecting the ingot treated in step (a) to a first upsetting deformation at 1100-1200° C., and then subjecting the ingot to a second upsetting deformation at 950-1100° C. to obtain a forging blank; and forging the forging blank at 950-1100° C. to obtain a slab;

[0033] (c) The slab is heat-treated at 1200-1400° C. for 8-48 hours, cooled, and then rolled at 980-1080° C. to obtain a homogeneous Ti2AlNb alloy sheet.

[0034] The present invention adopts a combined process of high-temperature homogenization treatment of Ti2AlNb alloy ingots, large deformation forging treatment, and high-temperature homogenization treatment of slabs to significantly improve the composition segregation of the obtained plate, thereby obtaining a homogeneous Ti2AlNb alloy plate. Specifically, the present invention reduces the element segregation of the ingot by performing a suitable homogenization treatment on the Ti2AlNb alloy ingot, and the element segregation size in the ingot is no more than 3mm. Then, after a certain deformation, the original large-scale segregation in the ingot is broken up, and a slab with a segregation size of less than 1.5mm is obtained. When the segregation size of the slab is reduced, the diffusion distance is reduced. At this time, performing a suitable high-temperature homogenization treatment on the slab is conducive to improving the diffusion uniformity, further reducing the composition segregation problem of the plate, and obtaining a homogeneous Ti2AlNb alloy plate.

[0035] Furthermore, the process of the present invention can significantly reduce the number of forging cycles, improve material utilization, and shorten the production cycle.

[0036] For example, in different embodiments, in step (a), the Ti2AlNb alloy ingot can be heat-insulated at 1260°C, 1280°C, 1300°C, 1320°C, 1350°C, 1380°C, 1400°C or a range consisting of any two thereof, and the heat-insulating treatment time can be 30h, 36h, 40h, 48h, 56h, 60h, 64h, 72h or a range consisting of any two thereof, which is more conducive to reducing the element segregation of the ingot, cooperating with the subsequent deformation process, refining the grains, and improving the processing plasticity of the alloy.

[0037] For example, in different embodiments, the temperature of the first upsetting deformation can be 1100°C, 1120°C, 1150°C, 1180°C, 1200°C, or a range consisting of any two thereof; the temperature of the second upsetting deformation can be 950°C, 980°C, 1000°C, 1020°C, 1050°C, 1080°C, 1100°C, or a range consisting of any two thereof; and the temperature of the slab obtained by forging can be 950°C, 980°C, 1000°C, 1020°C, 1050°C, 1080°C, 1100°C, or a range consisting of any two thereof. In actual operation, when the temperature decreases during the upsetting deformation and forging process, the hot material can be returned to the furnace. The upsetting deformation and forging temperatures of the present invention are more conducive to both reducing segregation size and reducing cracking.

[0038] For example, in different embodiments, in step (c), the slab can be heat-insulated at 1200°C, 1220°C, 1250°C, 1280°C, 1300°C, 1320°C, 1350°C, 1380°C, 1400°C, or any two thereof, and the heat-insulating time can be 8 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 40 hours, 48 hours, or any two thereof. The present invention reduces the segregation size in the slab to within 1.5 mm by subjecting the Ti2AlNb alloy ingot to high-temperature homogenization treatment and large-deformation forging treatment. Combined with the high-temperature homogenization treatment under the above conditions, the diffusion uniformity can be improved while avoiding coarse grains.

[0039] For example, in different embodiments, the rolling temperature may be 980° C., 1000° C., 1020° C., 1040° C., 1050° C., 1060° C., 1080° C., or a range consisting of any two thereof.

[0040] In a specific embodiment of the present invention, in step (a), the Ti2AlNb alloy ingot is charged into a furnace at room temperature during the holding treatment. Furthermore, the heating rate from room temperature to 1260-1400°C is ≤ 10°C / min, for example, 10°C / min, 8°C / min, 6°C / min, 5°C / min, or any combination thereof. The cooling in step (a) is furnace cooling and / or air cooling.

[0041] It is understandable that the heat preservation treatment time in the present invention is based on the time when the temperature reaches the target unless otherwise specified.

[0042] In a specific embodiment of the present invention, in the first upsetting deformation, the number of upsetting operations is greater than 2, for example, 3, 4, 5, etc. Furthermore, in the first upsetting deformation, the deformation amount of upsetting is 20% to 40%, for example, 20%, 25%, 30%, 35%, 40%, or any combination thereof, and the deformation amount of elongation is 20% to 40%, for example, 20%, 25%, 30%, 35%, 40%, or any combination thereof.

[0043] It should be understood that the number of upsetting cycles in the present invention refers to the number of alternating upsetting and lengthening cycles. The deformation during the upsetting deformation in steps (a) and (b) of the present invention is calculated as follows: the absolute value of the difference in height dimensions before and after deformation / the larger of the height dimensions before or after deformation. For example, the deformation for upsetting is the absolute value of the difference in height dimensions before and after deformation / the height dimension before deformation; for lengthening, the deformation is the absolute value of the difference in height dimensions before and after deformation / the height dimension after deformation.

[0044] In a specific embodiment of the present invention, in the second upsetting deformation, the number of upsetting operations is greater than 2, for example, 3, 4, 5, etc. Further, in the second upsetting deformation, the deformation amount of upsetting is 35% to 60%, for example, 35%, 40%, 45%, 50%, 55%, 60%, or a range consisting of any two thereof, and the deformation amount of elongation is 35% to 60%, for example, 35%, 40%, 45%, 50%, 55%, 60%, or a range consisting of any two thereof.

[0045] In a specific embodiment of the present invention, the forging process comprises 2 to 4 heats, with the deformation of each heat being 20% to 50%, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any two thereof. Furthermore, in step (b), the thickness of the slab is 120 to 350 mm, for example, 120 mm, 150 mm, 180 mm, 200 mm, 220 mm, 250 mm, 300 mm, 320 mm, 350 mm, or any two thereof.

[0046] In step (b) of the present invention, the deformation amount in the slab obtained by forging the forging blank is calculated as follows: (thickness value of the slab in the thickness direction at the forging front - thickness value of the slab in the thickness direction after forging) / thickness value of the slab in the thickness direction at the forging front.

[0047] The present invention deforms the ingot after high-temperature homogenization treatment. Through the above deformation conditions, it is more helpful to reduce the segregation size and reduce the diffusion distance, which is beneficial to improve the uniformity of diffusion in the subsequent slab homogenization treatment and improve the segregation situation.

[0048] In a specific embodiment of the present invention, in step (b), the ingot treated in step (a) is heat-treated at 1100-1200°C for 300-400 minutes, and then subjected to a first upsetting deformation; then, it is heat-treated at 980-1100°C for 300-400 minutes, and then subjected to a second upsetting deformation; and then, it is heat-treated at 980-1100°C for 300-400 minutes, and then forged to obtain a slab.

[0049] In a specific embodiment of the present invention, the segregation size of the Ti2AlNb alloy ingot after the treatment in step (a) is ≤3 mm; in step (b), the segregation size of the slab is ≤1.5 mm.

[0050] Among them, the segregation size of the present invention is obtained through the surface scanning results of the electron probe. Specifically, the area where the absolute value of the Nb weight percentage deviation (the difference between the measured value and the nominal value) is greater than 2% or the absolute value of the Al weight percentage deviation (the difference between the measured value and the nominal value) is greater than 1% is defined as the segregation area, and the size of the segregation area is measured.

[0051] In a specific embodiment of the present invention, in the heat preservation treatment of step (c), the charging temperature of the slab is 20-850°C. Furthermore, the heating rate from 20-850°C to 1200-1400°C is 5-20°C / min, for example, 5°C / min, 8°C / min, 10°C / min, 12°C / min, 15°C / min, 18°C / min, 20°C / min, or any combination thereof. The cooling in step (c) is furnace cooling and / or air cooling.

[0052] In a specific embodiment of the present invention, in step (c), the rolling includes at least two rounds of rolling deformation. Furthermore, the deformation of the initial rolling round is 20% to 40%, for example, 20%, 25%, 30%, 32%, 35%, 40%, or any two thereof, and the deformation of the final rolling round is 40% to 60%, for example, 40%, 45%, 50%, 55%, 60%, or any two thereof. The deformation during the rolling process is calculated as: the change in thickness of the slab before and after rolling / the thickness of the slab before deformation.

[0053] In a specific embodiment of the present invention, during the rolling in step (c), the holding time for each heat is 15 to 300 minutes. In actual operation, the holding time for each heat can be conventionally adjusted according to the thickness of the slab to be rolled.

[0054] In a specific embodiment of the present invention, in step (c), rolling includes two rounds of rolling deformation, and the rolling directions of the first round and the second round are different. For example, the rolling deformation of the first round is carried out along the width direction of the slab, and the rolling deformation of the second round is carried out along the length direction of the slab.

[0055] In a specific embodiment of the present invention, the thickness of the plate is 4 to 80 mm, for example, it can be 4 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm or a range consisting of any two thereof.

[0056] In a specific embodiment of the present invention, in step (b), the number of forging fires of the slab obtained from the ingot treated in step (a) is ≤ 9.

[0057] In a specific embodiment of the present invention, the preparation method further includes subjecting the homogeneous Ti2AlNb alloy plate to a solution treatment and an aging treatment. Furthermore, the solution treatment comprises holding at 950-980°C for 1-4 hours, followed by air cooling or oil quenching; and the aging treatment comprises holding at 760-820°C for 8-32 hours, followed by air cooling.

[0058] The second aspect of the present invention provides a homogeneous Ti2AlNb alloy plate produced by the method for producing the homogeneous Ti2AlNb alloy plate according to the first aspect of the present invention.

[0059] The Ti2AlNb alloy plate obtained by the method of the present invention has an absolute value of the deviation of the Nb weight percentage (the difference between the measured value and the nominal value) less than 2%, and an absolute value of the deviation of the Al weight percentage (the difference between the measured value and the nominal value) less than 1%.

[0060] The Ti2AlNb alloy of the present invention has a nominal composition of Ti-22Al-25Nb (at.%), but is not limited thereto. Any other Ti2AlNb-based alloy may be used. The Ti2AlNb alloy ingot of the present invention is produced by a conventional vacuum consumable melting process, which will not be described in detail herein.

[0061] Example 1

[0062] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, comprising the following steps:

[0063] (1) Set the size to The ingot is placed in an electric heating furnace at room temperature, heated to 1350℃ at a heating rate of 10℃ / min, and kept at 1350℃ for 48h. After the holding period, the furnace is cooled to below 800℃ and then taken out of the furnace for air cooling. After cooling to room temperature, the ingot is machined to remove the oxide scale. The size of the ingot after machining is

[0064] (2) The ingot treated in step (1) is kept at 1130° C. for 360 min in an electric heating furnace and then taken out of the furnace for upsetting. The billet with the size of X×Y×Z=465 mm×465 mm×670 mm is first upset and then elongated to obtain a billet with the size of X×Y×Z=410 mm×410 mm×860 mm. The hot material is returned to the furnace and kept at 1130° C. for 240 min. After the end of the holding period, the upsetting is continued. The billet with the size of X×Y×Z= The billet is then stretched to obtain a billet with dimensions of X×Y×Z = 410mm×410mm×860mm. The hot material is returned to the furnace and held at 1130°C for 240 minutes. After the holding period, it is upset to obtain a billet with dimensions of X×Y×Z = 505mm×505mm×560mm, and then stretched to obtain a billet with dimensions of X×Y×Z = 410mm×410mm×860mm. After completing the three upsetting deformations, the billet is air-cooled to room temperature and then polished to obtain a billet with dimensions of X×Y×Z = 405mm×405mm×855mm.

[0065] (3) The billet treated in step (2) is kept at 1040°C for 330 min in an electric heating furnace and then taken out of the furnace for upsetting. The billet is first upset to obtain a billet with a size of X×Y×Z=520mm×520mm×515mm, and then drawn to obtain a billet with a size of X×Y×Z=405mm×405mm×855mm; the hot material is returned to the furnace and kept at 1040°C for 240 min. After the end of the upsetting, the billet is first upset to obtain a billet with a size of X×Y×Z= The billet is then stretched to a size of 520mm×520mm×515mm, then stretched to a size of X×Y×Z = 405mm×405mm×855mm. The hot material is returned to the furnace and held at 1040°C for 240 minutes. After the holding period, it is upset to obtain a billet with dimensions of X×Y×Z = 520mm×520mm×515mm, and then stretched to obtain a billet with dimensions of X×Y×Z = 405mm×405mm×855mm. After completing the three upsetting deformations, the billet is air-cooled to room temperature and then polished to obtain a billet with dimensions of X×Y×Z = 400mm×400mm×850mm.

[0066] (4) The billet after the treatment in step (3) is kept at 1040°C for 320 minutes in an electric heating furnace and then taken out of the furnace for forging to form a forging billet with dimensions of X×Y×Z=280mm×540mm×900mm; the hot material is returned to the furnace and kept at 1040°C for 170 minutes. After the end of the heat preservation, it is further forged to form a forging billet with dimensions of X×Y×Z=195mm×735mm×950mm; the hot material is returned to the furnace and kept at 1040°C for 120 minutes. After the end of the heat preservation, it is further forged to form a forging billet with dimensions of X×Y×Z=135mm×960mm×1050mm. After completing the above three forgings, it is air-cooled and then polished to obtain a slab with dimensions of X×Y×Z=130mm×955mm×1045mm.

[0067] (5) The slab obtained in step (4) was placed in an electric heating furnace at room temperature, heated to 1300°C at a heating rate of 15°C / min, and kept at 1300°C for 24 hours. After the insulation was completed, it was air-cooled to room temperature and polished to obtain a slab with a size of X×Y×Z=125mm×950mm×1040mm.

[0068] (6) The slab obtained in step (5) is kept in an electric heating furnace at 1060°C for 120 minutes, then removed from the furnace and rolled along the Y direction into a slab with dimensions of X×Y×Z=75mm×1580mm×1040mm; the hot material is returned to the furnace and kept at 1060°C for 50 minutes. After the end of the holding period, it is rolled along the Z direction into a plate with dimensions of X×Y×Z=34mm×1580mm×2294mm. After rolling, the plate is air-cooled. After air-cooling to room temperature, the upper and lower large surfaces of the plate are polished to obtain a plate with dimensions of X×Y×Z=31mm×1580mm×2294mm.

[0069] (7) A test piece of X×Y×Z=31mm×120mm×200mm was cut from the plate obtained in step (6) and subjected to a heat treatment at 960°C / 2h / AC+780°C / 24h / AC. After the heat treatment, a mechanical property test was performed.

[0070] In the Ti2AlNb alloy plate of this embodiment, the absolute value of the deviation of the Nb weight percentage (the difference between the measured value and the nominal value) is less than 2%, and the absolute value of the deviation of the Al weight percentage (the difference between the measured value and the nominal value) is less than 1%.

[0071] Example 2

[0072] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, with the following differences:

[0073] In step (1), the holding temperature of the ingot is 1260°C;

[0074] In step (2), the holding temperature of the upsetting is 1100° C.;

[0075] In step (3), the holding temperature of the upsetting is 980°C;

[0076] In step (4), the forging holding temperature is 980°C;

[0077] In step (5), the slab is kept at a temperature of 1200°C;

[0078] In step (6), the rolling holding temperature is 980°C.

[0079] Example 3

[0080] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, with the following differences:

[0081] In step (1), the holding temperature of the ingot is 1400° C.;

[0082] In step (2), the holding temperature of the upsetting is 1200° C.;

[0083] In step (3), the holding temperature of the upsetting is 1100° C.;

[0084] In step (4), the forging holding temperature is 1100°C;

[0085] In step (5), the slab is kept at a temperature of 1400°C;

[0086] In step (6), the rolling holding temperature is 1080°C.

[0087] Example 4

[0088] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that step (3) is different.

[0089] Step (3) of this embodiment includes: keeping the billet processed in step (2) in an electric heating furnace at 1040° C. for 330 min, taking it out of the furnace and performing upsetting, first upsetting to obtain a billet with a size of X×Y×Z=500mm×500mm×560mm, and then stretching to obtain a billet with a size of X×Y×Z=405mm×405mm×855mm; returning the hot material to the furnace, keeping it at 1040° C. for 240 min, and continuing to upsetting after the end of the insulation, first upsetting to obtain a billet with a size of X×Y×Z=405mm×405mm×855mm. The billet is then stretched to a size of 405mm x 405mm x 855mm. The hot material is returned to the furnace and held at 1040°C for 240 minutes. After the holding period, it is upset to obtain a billet with dimensions of 500mm x 500mm x 560mm. The billet is then stretched to obtain a billet with dimensions of 405mm x 405mm x 855mm. After the three upsetting steps, the billet is air-cooled to room temperature and then polished to obtain a billet with dimensions of 400mm x 400mm x 850mm.

[0090] Example 5

[0091] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that in step (5), the holding temperature of the slab is 1250°C.

[0092] Example 6

[0093] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that in step (5), the holding temperature of the slab is 1350°C.

[0094] Example 7

[0095] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that in step (5), the holding temperature of the slab is 1400°C.

[0096] Example 8

[0097] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that in step (5), the holding temperature of the slab is 1200°C.

[0098] Example 9

[0099] This embodiment provides a method for preparing a homogeneous Ti2AlNb alloy plate, referring to Example 1, except that step (6) is different.

[0100] Step (6) of this embodiment includes: holding the slab obtained in step (5) in an electric heating furnace at 1060°C for 120 minutes, then removing it from the furnace and rolling it along the Y direction into a slab with dimensions of X×Y×Z=65mm×1826mm×1040mm; returning the hot material to the furnace, holding it at 1060°C for 50 minutes, and then rolling it along the Z direction into a plate with dimensions of X×Y×Z=34mm×1826mm×1988mm. After rolling, the plate is air-cooled, and after cooling to room temperature, the upper and lower surfaces of the plate are polished to obtain a plate with dimensions of X×Y×Z=31mm×1826mm×1988mm.

[0101] Comparative Example 1

[0102] Comparative Example 1: The preparation method of Reference Example 1 was followed by steps (1) to (4), and then:

[0103] (5) The slab obtained in step (4) is kept in an electric heating furnace at 1060°C for 120 minutes, then removed from the furnace and rolled along the Y direction into a slab with dimensions of X×Y×Z=75mm×1645mm×1040mm; the hot material is returned to the furnace and kept at 1060°C for 50 minutes. After the end of the holding period, it is rolled along the Z direction into a plate with dimensions of X×Y×Z=34mm×1645mm×2294mm. After rolling, the plate is air-cooled. After air-cooling to room temperature, the upper and lower large surfaces of the plate are polished to obtain a plate with dimensions of X×Y×Z=31mm×1645mm×2294mm.

[0104] (6) A test piece of X×Y×Z=31 mm×120 mm×200 mm was cut from the plate obtained in step (5) and subjected to a heat treatment at 960°C / 2 h / AC+780°C / 24 h / AC. After the heat treatment, a mechanical property test was performed.

[0105] Comparative Example 2

[0106] Comparative Example 2 refers to the preparation method of Example 1, except that: in step (1), the holding temperature of the ingot is 1250°C.

[0107] Comparative Example 3

[0108] Comparative Example 3 refers to the preparation method of Example 1, except that: in step (5), the insulation temperature of the slab is 1150°C.

[0109] Comparative Example 4

[0110] Comparative Example 4 refers to the preparation method of Example 1, except that: in step (2), the holding temperature of the upsetting is 1040°C.

[0111] Comparative Example 5

[0112] Comparative Example 5 refers to the preparation method of Example 1, except that: in step (3), the holding temperature of the upsetting is 1130°C.

[0113] Experimental example

[0114] Figure 1 and Figure 2 The electron probe analysis results of the Ti2AlNb alloy plates of Example 1 of the present invention and Comparative Example 1 are shown. As can be seen from the figure, the uniformity of the Ti2AlNb alloy plates obtained by the preparation method of the present invention is significantly better than that of Comparative Example 1.

[0115] The mechanical property test results of the plates of various embodiments and comparative examples after heat treatment are shown in Table 1.

[0116] Table 1 Mechanical properties of Ti2AlNb alloy plates

[0117]

[0118]

[0119] From the above test results, it can be seen that the present invention adopts a combined process of high-temperature homogenization treatment of Ti2AlNb alloy ingots, large deformation forging treatment, and high-temperature homogenization treatment of slabs, which significantly improves the composition segregation of the obtained plate, obtains homogeneous Ti2AlNb alloy plates, and can improve the mechanical properties of the plates.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a homogeneous Ti2AlNb alloy plate, characterized in that: The steps include: (a) The Ti2AlNb alloy ingot is heat-treated at 1260-1400°C for 30-72 hours and then cooled; (b) subjecting the ingot treated in step (a) to a first upsetting deformation at 1100-1200° C., and then subjecting the ingot to a second upsetting deformation at 950-1100° C. to obtain a forging blank; and forging the forging blank at 950-1100° C. to obtain a slab; (c) The slab is heat-treated at 1200-1400° C. for 8-48 hours, cooled, and then rolled at 980-1080° C. to obtain a homogeneous Ti2AlNb alloy plate.

2. The preparation method according to claim 1, characterized in that In the first upsetting deformation, the number of upsetting is greater than 2 times; Preferably, in the first upsetting deformation, the deformation amount of upsetting is 20% to 40%, and the deformation amount of drawing is 20% to 40%.

3. The preparation method according to claim 1, characterized in that In the second upsetting deformation, the number of upsetting is greater than 2 times; Preferably, in the second upsetting deformation, the deformation amount of upsetting is 35% to 60%, and the deformation amount of drawing is 35% to 60%.

4. The preparation method according to claim 1, characterized in that The slab obtained by forging includes 2 to 4 fires, and the deformation amount of each fire is 20% to 50%; Preferably, in step (b), the thickness of the slab is 120 to 350 mm.

5. The preparation method according to claim 1, characterized in that The segregation size of the Ti2AlNb alloy ingot after treatment in step (a) is ≤3 mm; in step (b), the segregation size of the slab is ≤1.5 mm.

6. The preparation method according to claim 1, characterized in that In step (c), the rolling includes at least two rolling deformations; Preferably, the deformation amount of the initial rolling fire is 20% to 40%, and the deformation amount of the final rolling fire is 40% to 60%.

7. The preparation method according to claim 1, characterized in that The thickness of the plate is 4 to 80 mm.

8. The preparation method according to claim 1, characterized in that In step (b), the slab is obtained by forging the ingot after being processed in step (a) for 9 or less times.

9. The preparation method according to claim 1, characterized in that The preparation method further comprises: subjecting the homogeneous Ti2AlNb alloy plate to a solution treatment and an aging treatment; Preferably, the solution treatment method includes: keeping at 950-980°C for 1-4 hours, and then air cooling or oil quenching; the aging treatment method includes: keeping at 760-820°C for 8-32 hours, and then air cooling.

10. Homogeneous Ti2AlNb alloy plate, characterized in that: The method is described in any one of claims 1 to 9.

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