A high-strength, high-impact-toughness near-beta titanium alloy and a preparation method and application thereof

Abstract

The application relates to the technical field of titanium alloy, and provides a high-strength and high-impact-toughness near-beta titanium alloy as well as a preparation method and application thereof.The high-strength and high-impact-toughness near-beta titanium alloy provided by the application comprises the following mass percentage of chemical elements: Mo: 3.2%-4.5%, Cr: 2.5%-4%, Fe: 0.5%-1.8%, Al: 0.5%-3%, and the balance of Ti and inevitable impurities, and the component ratio satisfies 9<[Mo] eq <11; the metallographic structure of the high-strength and high-impact-toughness near-beta titanium alloy comprises coarse alpha lamellar structure and fine alpha lamellar structure.Through the design of the titanium alloy component and the regulation of the organizational structure, the plasticity and toughness of the titanium alloy are greatly improved while the high strength is considered, the excellent matching of the strength, plasticity and impact toughness is realized, and the high-strength and high-impact-toughness near-beta titanium alloy has a wide application prospect in the petroleum industry field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium alloy, and particularly relates to a high-strength and high-impact-toughness near-beta titanium alloy and a preparation method and application thereof. BACKGROUND

[0002] Titanium and titanium alloy are widely used in aerospace, chemical industry, medical treatment and marine engineering due to excellent performance. For example, titanium alloy has excellent corrosion resistance and can be used for a long time in extremely harsh environmental conditions, and is particularly suitable for corrosive environments such as seawater and acidic medium. The high specific strength, light weight and good high-temperature performance make it a key material in high-tech fields such as engine turbine blades and aircraft structural parts.

[0003] In the field of petroleum industry, titanium alloy oil well pipe has excellent characteristics such as high specific strength, good corrosion resistance, low elastic modulus, easy cold forming and seawater erosion resistance, and is widely used in deep wells, ultra-deep wells, short radius horizontal wells and high-acid oil and gas wells. At present, the main titanium alloy oil well pipe is TC4.

[0004] However, with the continuous development of oil and gas exploration to unconventional oil and gas resources such as deep water, high temperature and high pressure, and high corrosion, higher requirements are put forward for the impact toughness and strength of oil well pipe materials. As an alpha + beta type titanium alloy, TC4 can usually improve the strength through heat treatment, but the increase in strength is often accompanied by a decrease in plasticity and impact toughness, which cannot achieve the balance of strength, plasticity and toughness, and affects its further application in the field of petroleum industry. SUMMARY

[0005] Therefore, the present application provides a high-strength and high-impact-toughness near-beta titanium alloy and a preparation method and application thereof. The near-beta titanium alloy provided by the present application has high strength, good plasticity and toughness, and has broad prospects in the field of petroleum industry.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A high-strength and high-impact-toughness near-beta titanium alloy comprises the following mass percentage of chemical elements: Mo: 3.2% to 4.5%, Cr: 2.5% to 4%, Fe: 0.5% to 1.8%, Al: 0.5% to 3%, and the balance is Ti and inevitable impurities.

[0008] The molybdenum equivalent of the high-strength and high-impact-toughness near-beta titanium alloy is denoted as [Mo] eq , and the value of [Mo] eq is: 9<[Mo] eq <11.

[0009] The [Mo] eq is obtained from formula I:

[0010] [Mo] eq =1[Mo]+1.6[Cr]+2.90[Fe]-1[Al];

[0011] formula I;

[0012] [Mo], [Cr], [Fe], [Al] in formula I represent the mass percentage of each element in the high-strength and high-impact toughness near-beta titanium alloy, respectively;

[0013] The metallographic structure of the high-strength and high-impact toughness near-beta titanium alloy comprises coarse alpha lamellar structure and fine alpha lamellar structure.

[0014] Preferably, the chemical elements comprise the following mass percentages: Mo: 3.58%, Cr: 2.97%, Fe: 1.06%, Al: 1.06%, and the balance being Ti and inevitable impurities.

[0015] Preferably, the chemical elements comprise the following mass percentages: Mo: 3.50%, Cr: 2.97%, Fe: 0.98%, Al: 2.01%, and the balance being Ti and inevitable impurities.

[0016] Preferably, the high-strength and high-impact toughness near-beta titanium alloy has a tensile strength greater than 1000 MPa, a yield strength greater than 900 MPa, an elongation at break greater than 12%, and an impact toughness greater than 50 J / cm 2 .

[0017] The application also provides a preparation method of the high-strength and high-impact toughness near-beta titanium alloy according to the above scheme, comprising the following steps:

[0018] According to the chemical element composition of the high-strength and high-impact toughness near-beta titanium alloy according to the above scheme, the raw materials are melted to obtain a titanium alloy ingot;

[0019] The titanium alloy ingot is subjected to hot deformation processing to obtain a titanium alloy blank;

[0020] The titanium alloy blank is subjected to heat treatment to obtain the high-strength and high-impact toughness near-beta titanium alloy; the heat treatment comprises sequentially performing first holding, first cooling, second holding, and second cooling; the temperature of the first holding is 800-900℃, and the holding time is 1-4h; the first cooling is furnace cooling from the temperature of the first holding to the temperature of the second holding; the temperature of the second holding is 500-600℃, and the holding time is 4-8h; and the second cooling is air cooling.

[0021] Preferably, the melting is vacuum arc melting, the temperature of the melting is 2000-2500℃, and the number of melting is 2-6 times.

[0022] Preferably, the hot deformation process comprises sequentially performing open-die forging and hot rolling.

[0023] Preferably, the open-die forging is performed at a temperature of 1000-1200℃.

[0024] Preferably, the hot rolling is performed at a temperature of 900-1000℃, with a pass deformation of 5%-10% and a cumulative deformation of greater than 50%.

[0025] The application also provides application of the high-strength and high-impact-toughness near-beta titanium alloy or the high-strength and high-impact-toughness near-beta titanium alloy prepared by the preparation method in the field of petroleum industry.

[0026] The application provides a high-strength and high-impact-toughness near-beta titanium alloy, comprising the following mass percentage of chemical elements: Mo: 3.2%-4.5%, Cr: 2.5%-4%, Fe: 0.5%-1.8%, Al: 0.5%-3%, and the balance being Ti and inevitable impurities; the molybdenum equivalent of the high-strength and high-impact-toughness near-beta titanium alloy is denoted as [Mo] eq , and the value of [Mo] eq is 9<[Mo] eq <11; and the high-strength and high-impact-toughness near-beta titanium alloy comprises coarse alpha lamellar structure and fine alpha lamellar structure.The titanium alloy currently in use generally comprises alpha phase and beta phase, wherein the alpha phase is HCP structure (hard), the beta phase is BCC structure (soft), and the difference between the hardness and modulus of the two is large, which leads to incoordination of strain in the deformation process, and cracks are prone to be generated at the beta / alpha phase interface, thereby reducing the plasticity and toughness of the material. The application adopts Mo, Cr and Fe elements as beta stabilizing elements, which can not only stabilize the beta phase, but also strengthen the beta phase, effectively reducing the difference between the hardness and modulus of the beta phase and the alpha phase, thereby relieving the stress concentration at the beta / alpha phase interface and improving the plasticity and toughness of the titanium alloy. Al acts as a main alpha stabilizing element, which plays a role in strengthening the alpha phase and improving the strength of the material. Meanwhile, through a large amount of research, it is found that when [Mo] eq is 9-11, the metastable beta phase at high temperature can be preserved to room temperature, and fine alpha phase can be precipitated after low-temperature aging, thereby significantly improving the strength of the alloy. Therefore, through the design of the titanium alloy composition, the application not only significantly improves the material strength, but also effectively reduces the difference between the hardness and modulus of the two phases, and relieves the interface stress concentration phenomenon, thereby realizing the synergistic improvement of plasticity and toughness.

[0027] In addition, the titanium alloy provided by the application has a heterogeneous lamellar structure composed of coarse alpha lamellae and fine alpha lamellae, wherein the coarse alpha lamellae are beneficial to improving plasticity and toughness, and the fine alpha lamellae can significantly improve the strength of the alloy, and through the regulation of the structure of the titanium alloy, the plasticity and toughness of the titanium alloy are greatly improved while the high strength is taken into account.

[0028] The application further provides a preparation method of the high-strength and high-impact-toughness near-beta titanium alloy.

[0029] In summary, the titanium alloy provided by the application has high strength and good plasticity and toughness, realizes excellent matching of strength, plasticity and impact toughness, and has broad application prospects in the field of petroleum industry. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 SEM image of the high-strength and high-impact-toughness near-beta titanium alloy prepared in Example 1. DETAILED DESCRIPTION

[0031] The application provides a high-strength and high-impact-toughness near-beta titanium alloy, which comprises the following mass percentage of chemical elements: Mo: 3.2% to 4.5%, Cr: 2.5% to 4%, Fe: 0.5% to 1.8%, Al: 0.5% to 3%, and the balance is Ti and inevitable impurities.

[0032] The molybdenum equivalent of the high-strength and high-impact-toughness near-beta titanium alloy is denoted as [Mo] eq , and the value of [Mo] eq is 9<[Mo] eq <11.

[0033] The [Mo] eq is obtained from formula I:

[0034] [Mo] eq =1[Mo]+1.60[Cr]+2.9[Fe]-1[Al];

[0035] Formula I;

[0036] [Mo], [Cr], [Fe], [Al] in formula I represent the mass percentage of each element in the high-strength and high-impact toughness near-beta titanium alloy respectively;

[0037] The high-strength and high-impact toughness near-beta titanium alloy has a metallographic structure including coarse alpha lamellar structure and fine alpha lamellar structure.

[0038] Unless otherwise specified, each raw material / component used in the present application is commercially available.

[0039] The high-strength and high-impact toughness near-beta titanium alloy provided by the present application includes Mo 3.2% to 4.5%, preferably 3.5% to 4%, and specifically 3.5% or 3.58% in terms of mass percentage.

[0040] The high-strength and high-impact toughness near-beta titanium alloy provided by the present application includes Cr 2.5% to 4%, preferably 2.8% to 3%, and specifically 2.97% in terms of mass percentage.

[0041] The high-strength and high-impact toughness near-beta titanium alloy provided by the present application includes Fe 0.5% to 1.8%, preferably 0.8% to 1.2%, and specifically 0.98% or 1.06% in terms of mass percentage.

[0042] In the present application, the Mo, Cr, and Fe can stabilize and strengthen the beta phase, effectively reduce the difference in hardness and modulus between the beta phase and the alpha phase, thereby relieving the stress concentration at the interface between the beta phase and the alpha phase, and improving the plasticity and toughness of the titanium alloy.

[0043] The high-strength and high-impact toughness near-beta titanium alloy provided by the present application includes Al 0.5% to 3%, preferably 1 to 2.1%, and specifically 1.06% or 2.01% in terms of mass percentage. In the present application, the Al element can stabilize and strengthen the alpha phase, thereby improving the strength of the titanium alloy.

[0044] The high-strength and high-impact toughness near-beta titanium alloy provided by the present application further includes Ti and unavoidable impurities in terms of mass percentage.

[0045] In the present application, the Mo equivalent of the high-strength and high-impact toughness near-beta titanium alloy is denoted as [Mo] eq , the value of [Mo] eq is: 9<[Mo] eq <11. Specifically, the value of [Mo] eq may be 9.084, 9.5, 9.6, 9.8, 10, or 10.346. The present application controls [Mo] eq within the above range, can retain the metastable beta phase at high temperature to room temperature, and can precipitate fine alpha phase after low-temperature aging, thereby significantly improving the strength of the titanium alloy.

[0046] In the present application, the high-strength and high-impact-toughness near-beta titanium alloy has a tensile strength greater than 1000 MPa, preferably 1010-1064 MPa, a yield strength greater than 900 MPa, preferably 905-957 MPa, an elongation at break greater than 12%, preferably 13%-15%, and an impact toughness greater than 50 J / cm 2 , preferably 51-56 J / cm 2 .

[0047] In the present application, the high-strength and high-impact-toughness near-beta titanium alloy has a microstructure including coarse alpha lamellar structure and fine alpha lamellar structure, the coarse alpha lamellar structure having a width of 0.6-1.9 μm, and the fine alpha lamellar structure having a width of 0.12-0.35 μm.

[0048] The present application also provides a preparation method of the high-strength and high-impact-toughness near-beta titanium alloy according to the above-mentioned scheme, including the following steps:

[0049] According to the chemical element composition of the high-strength and high-impact-toughness near-beta titanium alloy according to the above-mentioned scheme, raw materials are smelted to obtain a titanium alloy ingot.

[0050] The titanium alloy ingot is subjected to hot deformation processing to obtain a titanium alloy blank.

[0051] The titanium alloy blank is subjected to heat treatment to obtain the high-strength and high-impact-toughness near-beta titanium alloy.

[0052] According to the chemical element composition of the high-strength and high-impact-toughness near-beta titanium alloy according to the above-mentioned scheme, raw materials are smelted to obtain a titanium alloy ingot. In the present application, the raw materials are titanium particles, molybdenum particles, chromium particles, iron particles and aluminum particles; the purity of the raw materials is preferably ≥ 99.0%; the smelting is preferably vacuum arc smelting, the temperature of the smelting is preferably 2000-2500 °C, and the number of smelting is preferably 2-6 times, specifically 3 times.

[0053] After obtaining the titanium alloy ingot, the titanium alloy ingot is subjected to hot deformation processing to obtain a titanium alloy blank. In the present application, the hot deformation processing preferably includes sequentially performing open forging and hot rolling; the temperature of the open forging is preferably 1000-1200 °C, specifically 1050 °C, 1100 °C or 1150 °C. The present application preferably first keeps the titanium alloy ingot at the temperature of the open forging for 1 h, and then performs open forging; in a specific embodiment of the present application, a rod-shaped sample with a length of 300 mm, a width of 60 mm and a thickness of 40 mm is obtained by open forging.

[0054] In the present application, the temperature of the hot rolling is preferably 900-1000℃, and can be 900℃, 950℃ or 1000℃ in particular; the pass deformation of the hot rolling is preferably 5%-10%, and the cumulative deformation is preferably greater than 50%, and can be 60% in particular.

[0055] After obtaining the titanium alloy blank, the present application performs heat treatment on the titanium alloy blank to obtain the high-strength and high-impact-toughness near-beta titanium alloy. In the present application, the heat treatment comprises sequentially performing first holding, first cooling, second holding and second cooling; the temperature of the first holding is 800-900℃, and can be 850℃ in particular, and the holding time is 1-4h, and can be 1h, 2h, 3h or 4h in particular; the first cooling is furnace cooling from the temperature of the first holding to the temperature of the second holding; the temperature of the second holding is 500-600℃, and can be 550℃ in particular, and the holding time is 4-8h, and can be 4h, 5h, 6h, 7h or 8h in particular; and the second cooling is air cooling. Through the above heat treatment method, the present application can obtain a heterogeneous lamellar structure composed of coarse alpha lamellae and fine alpha lamellae, which can greatly improve the plasticity and toughness of the titanium alloy while taking into account high strength.

[0056] The present application also provides the application of the high-strength and high-impact-toughness near-beta titanium alloy in the above-mentioned scheme or the high-strength and high-impact-toughness near-beta titanium alloy prepared by the preparation method in the above-mentioned scheme in the field of petroleum industry. The titanium alloy provided by the present application has high strength, good plasticity and impact toughness, and has broad application prospects in the field of petroleum industry.

[0057] The technical solutions in the present application will be clearly and completely described below in combination with the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0058] Embodiment 1

[0059] The present embodiment provides a high-strength and high-impact-toughness near-beta titanium alloy. The chemical element composition of the titanium alloy, in terms of mass percentage, is: Mo: 3.58%, Cr: 2.97%, Fe: 1.06%, Al: 1.06%, and the balance is Ti and inevitable impurities.

[0060] The titanium alloy is prepared by the following method: high-purity titanium, molybdenum, chromium, iron and aluminum particles are used to prepare raw materials according to the component ratio, vacuum arc melting is used to repeatedly melt the raw materials for three times to obtain titanium alloy ingots; the titanium alloy ingots are kept at 1050 ℃ for 1 h, and then open forging is performed to obtain a rod-shaped sample with a length of 300 mm, a width of 60 mm and a thickness of 40 mm; then hot rolling is performed at 900 ℃, and the deformation of each pass is 10%, and the total deformation is 60%; the hot-rolled sample is placed in a vacuum tube furnace at 850 ℃ for heat treatment for 1 h, then furnace cooling is performed to 550 ℃, and then the sample is kept at 550 ℃ for 6 h and air-cooled to obtain a high-strength and high-impact toughness near-beta titanium alloy.

[0061] The mechanical property test samples are cut from the prepared high-strength and high-impact toughness near-beta titanium alloy sample, wherein the tensile test sample is a plate-shaped sample with a gauge length of 25 mm, a width of 5 mm and a thickness of 2 mm; and the impact test sample is a V-shaped notch sample with a size of 55 mm x 10 mm x 10 mm. The mechanical property test results show that the high-strength and high-impact toughness near-beta titanium alloy prepared in the embodiment has a tensile strength of 1010 MPa, a yield strength of 905 MPa, an elongation at break of 15%, and an impact toughness of 56 J / cm 2 .

[0062] Figure 1 FIG. 1 is a SEM image of the high-strength and high-impact toughness near-beta titanium alloy prepared in the embodiment, and FIG. 2 is a TEM image of the high-strength and high-impact toughness near-beta titanium alloy prepared in the embodiment. Figure 1 As can be seen from FIGS. 1 and 2, the microstructure of the titanium alloy prepared in the embodiment is a heterogeneous lamellar structure, which contains two morphologies of alpha phase: fine alpha lamellar and coarse alpha lamellar. The fine alpha lamellar can improve the strength of the alloy, and the coarse alpha lamellar can effectively hinder the propagation of cracks, thereby improving the impact toughness and plasticity of the alloy.

[0063] Embodiment 2

[0064] The embodiment provides a high-strength and high-impact toughness near-beta titanium alloy. The chemical element composition of the titanium alloy, in terms of mass percentage, is as follows: Mo: 3.50%, Cr: 2.97%, Fe: 0.98%, Al: 2.01%, and the balance being Ti and inevitable impurities.

[0065] The titanium alloy is prepared by the following method: high-purity titanium, molybdenum, chromium, iron and aluminum particles are used to prepare raw materials according to the component ratio, vacuum arc melting is used to repeatedly melt the raw materials for three times to obtain titanium alloy ingots; the titanium alloy ingots are kept at 1050 ℃ for 1 h, and then open forging is performed to obtain a rod-shaped sample with a length of 300 mm, a width of 60 mm and a thickness of 40 mm; then hot rolling is performed at 900 ℃, and the deformation of each pass is 10%, and the total deformation is 60%; the hot-rolled sample is placed in a vacuum tube furnace at 850 ℃ for heat treatment for 1 h, then furnace cooling is performed to 550 ℃, and then the sample is kept at 550 ℃ for 6 h and air-cooled to obtain a high-strength and high-impact toughness near-beta titanium alloy.

[0066] The mechanical property test samples were cut from the prepared high-strength and high-impact toughness near-β titanium alloy sample, wherein the tensile test sample was a plate-shaped sample with a gauge length of 25 mm, a width of 5 mm, and a thickness of 2 mm; and the impact test sample was a V-notch sample with a size of 55 mm x 10 mm x 10 mm. The mechanical property test results showed that the high-strength and high-impact toughness near-β titanium alloy prepared in the embodiment had a tensile strength of 1064 MPa, a yield strength of 957 MPa, an elongation at break of 13%, and an impact toughness of 51 J / cm 2 .

[0067] Comparative Example 1

[0068] The comparative example provided an α+β type titanium alloy, which had a chemical element composition of Al: 5.84%, V: 4.05%, and the balance of Ti and inevitable impurities in terms of mass percentage.

[0069] The preparation method of the α+β type titanium alloy was as follows: high-purity titanium, vanadium, and aluminum particles were used to prepare raw materials according to the component ratio, vacuum arc melting was used to melt the raw materials for 3 times to obtain an ingot; the melted ingot was kept at 1050 ℃ for 1 h, and then open-die forging was performed to obtain a rod-shaped sample with a length of 300 mm, a width of 60 mm, and a thickness of 40 mm; then hot rolling was performed at 900 ℃, and the deformation amount of each pass was 10%, and the total deformation amount was 60%; the hot-rolled sample was placed in a vacuum tube furnace at 850 ℃ for heat treatment for 1 h, then furnace-cooled to 550 ℃, and then kept at 550 ℃ for 6 h and air-cooled to obtain the α+β type titanium alloy.

[0070] The mechanical property test samples were cut from the prepared α+β titanium alloy, wherein the tensile test sample was a plate-shaped sample with a gauge length of 25 mm, a width of 5 mm, and a thickness of 2 mm; and the impact test sample was a V-notch sample with a size of 55 mm x 10 mm x 10 mm. The mechanical property test results showed that the α+β titanium alloy had a tensile strength of 975 MPa, a yield strength of 868 MPa, an elongation at break of 12%, and an impact toughness of 47 J / cm 2 .

[0071] The mechanical property test results of the titanium alloys prepared in Examples 1-2 and Comparative Example 1 were summarized in Table 1.

[0072] Table 1: Summary of mechanical property test results

[0073]

[0074] According to the results in Table 1, it can be seen that the titanium alloy prepared in the present application has higher tensile strength, yield strength, elongation, and impact toughness compared with Comparative Example 1.

[0075] To sum up, the application effectively reduces the difference between the hardness and modulus of the beta phase and the alpha phase by controlling the content of Mo, Cr, Fe and Al strengthening elements, thereby improving the strength and toughness. At the same time, by optimizing the heat treatment process, a heterogeneous lamellar structure with coarse and fine alpha lamellae is prepared, which greatly improves the plasticity and toughness of the titanium alloy while taking into account the high strength, and realizes the excellent matching of strength, plasticity and impact toughness, and has broad prospects in the field of petroleum industry.

[0076] The above only describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A high strength, high impact toughness near beta titanium alloy characterized in that, Chemical elements with the following mass percentage contents: Mo: 3.2%~4.5%, Cr: 2.5%~4%, Fe: 0.5%~1.8%, Al: 0.5%~3%, the balance being Ti and inevitable impurities; The high-strength, high-impact-toughness near-beta titanium alloy is denoted as [Mo] eq , and the value of [Mo] eq is: 9<[Mo] eq <11. said [Mo] eq obtained from formula I: [Mo] eq = 1 [Mo] + 1.6 [Cr] + 2.90 [Fe] - 1 [Al]; Formula I; [Mo], [Cr], [Fe], [Al] in Formula I represent the mass percentage contents of each element in the high-strength and high-impact-toughness near-beta titanium alloy, respectively; The high-strength and high-impact-toughness near-beta titanium alloy has a metallographic structure comprising coarse alpha lamellar structure and fine alpha lamellar structure; The preparation method of the high-strength and high-impact-toughness near-beta titanium alloy comprises the following steps: According to the chemical element composition of the high-strength and high-impact-toughness near-beta titanium alloy, raw materials are smelted to obtain a titanium alloy ingot; The titanium alloy ingot is subjected to hot deformation processing to obtain a titanium alloy blank; The titanium alloy blank is subjected to heat treatment to obtain the high-strength and high-impact-toughness near-beta titanium alloy; the heat treatment comprises sequentially performing first heat preservation, first cooling, second heat preservation and second cooling; the temperature of the first heat preservation is 800~900℃, and the heat preservation time is 1~4 h; the first cooling is furnace cooling from the temperature of the first heat preservation to the temperature of the second heat preservation; the temperature of the second heat preservation is 500~600℃, and the heat preservation time is 4~8 h; and the second cooling is air cooling.

2. The high-strength, high-impact-toughness near-beta titanium alloy of claim 1, wherein, Chemical elements with the following mass percentage contents: Mo: 3.58%, Cr: 2.97%, Fe: 1.06%, Al: 1.06%, the balance being Ti and inevitable impurities.

3. The high-strength, high-impact-toughness near-beta titanium alloy of claim 1, wherein, Chemical elements with the following mass percentage contents: Mo: 3.50%, Cr: 2.97%, Fe: 0.98%, Al: 2.01%, the balance being Ti and inevitable impurities.

4. The high-strength, high-impact-toughness near-beta titanium alloy of claim 1, wherein, The high-strength, high-impact-toughness near-beta titanium alloy has a tensile strength greater than 1000 MPa, a yield strength greater than 900 MPa, an elongation at break greater than 12%, and an impact toughness greater than 50 J / cm 2 .

5. The high-strength, high-impact toughness near beta titanium alloy of claim 1, wherein, The smelting is vacuum arc smelting, the temperature of the smelting is 2000~2500℃, and the smelting frequency is 2~6 times.

6. The high-strength, high-impact toughness near beta titanium alloy of claim 1, wherein, The hot deformation processing comprises sequentially performing open-blank forging and hot rolling.

7. The high-strength, high-impact toughness near beta titanium alloy of claim 6, wherein, The temperature of the open-blank forging is 1000~1200℃.

8. The high-strength, high-impact toughness near beta titanium alloy of claim 6, wherein, The temperature of the hot rolling is 900~1000℃, the pass deformation amount is 5%~10%, and the cumulative deformation amount is greater than 50%.

9. Application of the high-strength and high-impact-toughness near-beta titanium alloy according to any one of claims 1~8 in the field of petroleum industry.

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