阅读说明：本技术 一种1200MPa级耐硝酸腐蚀高强度钛合金及其制备方法 (1200 MPa-level nitric acid corrosion resistant high-strength titanium alloy and preparation method thereof ) 是由 吴俊宇 李欢 刘承泽 吴金平 赵恒章 刘后龙 刘向甲 余中狄 于 2021-10-12 设计创作，主要内容包括：本发明公开了一种1200MPa级耐硝酸腐蚀高强度钛合金,由以下质量含量的成分组成：Ta4.5%～5.5%,V4.5%～5.5%,Cr7.5%～8.5%,Al≤1.5%,其余为Ti及不可避免的杂质；本发明还公开了一种制备钛合金的方法,该方法包括：一、准备原料并熔炼制备钛合金铸锭；二、锻造得到钛合金锻件；三、热处理得到钛合金。本发明的钛合金通过添加Cr与Ta发挥析出强化的作用,通过添加Ta促进钛合金表层氧化膜形成,同时提高了钛合金的强度和耐蚀性能,解决了耐蚀钛合金强度不足、而高强度钛合金耐蚀性普遍不满足后处理工况的问题；本发明的制备方法有利于获得性能优异的钛合金。(The invention discloses a 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy which comprises the following components in percentage by mass: 4.5 to 5.5 percent of Ta4, 4.5 to 5.5 percent of V, 7.5 to 8.5 percent of Cr7, less than or equal to 1.5 percent of Al, and the balance of Ti and inevitable impurities; the invention also discloses a method for preparing the titanium alloy, which comprises the following steps: firstly, preparing raw materials and smelting to prepare a titanium alloy ingot; secondly, forging to obtain a titanium alloy forging; thirdly, carrying out heat treatment to obtain the titanium alloy. According to the titanium alloy, Cr and Ta are added to play a role in precipitation strengthening, the formation of an oxide film on the surface layer of the titanium alloy is promoted by adding Ta, the strength and the corrosion resistance of the titanium alloy are improved, and the problems that the corrosion resistance of the corrosion-resistant titanium alloy is insufficient and the corrosion resistance of the high-strength titanium alloy generally does not meet the post-treatment working condition are solved; the preparation method of the invention is beneficial to obtaining the titanium alloy with excellent performance.)

1. The 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy is characterized by comprising the following components in percentage by mass: 4.5 to 5.5 percent of Ta4, 4.5 to 5.5 percent of V, 7.5 to 8.5 percent of Cr7, less than or equal to 1.5 percent of Al, and the balance of Ti and inevitable impurities; the tensile strength of the titanium alloy is not less than 1200MPa, the yield strength is not less than 1100MPa, the elongation is not less than 5%, and the corrosion rate under 6mol of boiling nitric acid is not more than 0.05 mm/a.

2. The titanium alloy as claimed in claim 1, wherein the inevitable impurities are present in an amount of no more than 0.1% by mass.

3. A method for preparing the 1200MPa grade nitric acid corrosion resistant high strength titanium alloy of claim 1 or claim 2, comprising the steps of:

step one, preparing raw materials according to design components of a target product titanium alloy, and then smelting to prepare a titanium alloy ingot; the Ta element in the target product titanium alloy is added by taking Ti-Ta intermediate alloy as a raw material, and the V element and the Al element are added by taking V-Al intermediate alloy as a raw material;

step two, forging the titanium alloy ingot obtained in the step one to obtain a titanium alloy forging;

and step three, carrying out heat treatment on the titanium alloy forging obtained in the step two to obtain the 1200 MPa-level nitric acid corrosion resistant high-strength titanium alloy.

4. The method according to claim 3, wherein the titanium alloy forging obtained in the second step is hot-rolled to obtain a titanium alloy rolled piece, and then the titanium alloy rolled piece is heat-treated in the third step to obtain the 1200MPa nitric acid corrosion resistant high-strength titanium alloy.

5. The method of claim 3, wherein the melting process in step one is a vacuum consumable arc melting process, a non-consumable vacuum arc furnace melting process, a cold hearth melting process, a cold crucible melting process, and an electroslag melting process.

6. The method of claim 3, wherein the forging in step two has not less than three heats.

7. The method of claim 3, wherein the forging in the second step comprises cogging forging, intermediate forging and finished product forging, and the temperature of the cogging forging is not lower than 1100 ℃, the temperature of the intermediate forging is 900 ℃ to 950 ℃, the heat number of the intermediate forging is not lower than 1, and the temperature of the finished product forging is 780 ℃ to 820 ℃.

8. The method of claim 4 wherein the titanium alloy rolled stock in step three is a plate, bar, tube or wire.

9. The method of claim 4, wherein the temperature of the hot rolling in step three is 780 ℃ to 820 ℃.

10. The method according to claim 3 or 4, wherein the heat treatment is carried out by: firstly carrying out solid solution, air cooling or quenching to room temperature, then carrying out aging, air cooling or quenching to room temperature; the solid solution temperature is 760-800 ℃, the solid solution time is less than 1h, the aging temperature is 460-490 ℃, and the aging time is not less than 5 h.

Technical Field

The invention belongs to the technical field of titanium alloy, and particularly relates to a 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy and a preparation method thereof.

Background

With the mature application of the third-generation nuclear power technology 'Hualong I' in China, the development speed of nuclear power in China is gradually increased, and the generation amount and the storage amount of nuclear spent fuel are increased, so that higher requirements are put forward on the post-processing capacity of the nuclear spent fuel in China, and the planning and the construction of a large-scale commercial post-processing plant are not slow enough. When fissionable elements in the spent fuel are extracted and recovered in the nuclear chemical industry, boiling or sub-boiling concentrated nitric acid is needed to be adopted to dissolve the spent fuel, which can form a severe test on the corrosion resistance of related materials. The method has the advantages that the boiling-resistant nitric acid corrosion-resistant alloy material is adopted to manufacture related equipment and instruments, so that a reliable solution for relieving and guaranteeing the safety of nuclear chemical engineering is provided, and the high operation reliability of the related equipment in a severe nitric acid environment can be guaranteed. With the gradual expansion of the scale of the post-treatment plant, the equipment is inevitably large, which inevitably puts higher requirements on the strength of the corrosion-resistant material, and how to realize higher strength on the premise of ensuring the corrosion resistance of the material becomes a key concern of the post-treatment industry.

In recent years, Ti-Ta and Ti-Ta-Nb alloys which have excellent nitric acid corrosion resistance are developed in succession in main nuclear power countries. However, the strength of the existing titanium alloy for post-treatment is generally below 600MPa, and the requirement of certain special working conditions on the high-strength corrosion-resistant alloy is difficult to meet. The alloy strength can be improved by increasing the content of the b stable element in the titanium alloy through solid solution strengthening, and meanwhile, the metastable beta titanium alloy can be designed by controlling the Mo equivalent, so that the precipitation strengthening effect is realized through aging decomposition. At present, various high-strength b titanium alloys have been developed according to the design concept, but the alloys are designed for aerospace materials, the corrosion resistance is generally poor under the boiling concentrated nitric acid environment, and the requirement that some key parts have a corrosion rate of less than 0.1mm/a is difficult to meet.

Disclosure of Invention

The invention aims to solve the technical problem of providing a 1200MPa nitric acid corrosion resistant high-strength titanium alloy aiming at the defects of the prior art. The titanium alloy plays a role in precipitation strengthening by adding the Cr element and the Ta element, the strength of the titanium alloy is improved, meanwhile, the Ta element is added to promote the formation of an oxide film on the surface layer of the titanium alloy, the corrosion resistance of the titanium alloy is improved, the high-strength corrosion-resistant titanium alloy with tensile strength of more than 1200MPa and good plasticity and corrosion resistance is obtained, and the problems that the existing corrosion-resistant titanium alloy for the post-processing industry is insufficient in strength, and the corrosion resistance of the high-strength titanium alloy generally cannot meet the post-processing working condition are solved.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy is characterized by comprising the following components in percentage by mass: 4.5 to 5.5 percent of Ta4, 4.5 to 5.5 percent of V, 7.5 to 8.5 percent of Cr7, less than or equal to 1.5 percent of Al, and the balance of Ti and inevitable impurities; the tensile strength of the titanium alloy is not less than 1200MPa, the yield strength is not less than 1100MPa, the elongation is not less than 5%, and the corrosion rate under 6mol of boiling nitric acid is not more than 0.05 mm/a.

The invention firstly controls the stability of beta phase through the design of alloying elements, and the Mo equivalent [ Mo ] of the titanium alloy]_cqControlled within a certain range ([ Mo ]]_cqAnd = 15-17), aiming at preserving a beta-phase single-phase structure at room temperature, precipitating a fine and dispersed alpha phase during aging, exerting a second-phase strengthening effect and improving the strength of the titanium alloy. Specifically, the invention promotes Cr in the aging process on the one hand by adding Cr element and controlling the addition amount thereof₂Ta and Cr₂The Ti phase is separated out along with the alpha phase together to play a role of separation strengthening, on the other hand, the corrosion resistance of the alloy is obviously improved due to the self-passivation characteristic of the Cr element, and the problems of serious segregation caused by excessive Cr addition and excessive separated phase to deteriorate the plasticity of the titanium alloy are avoided; solid solution strengthening is carried out by adding V element instead of conventional Mo addition to improveThe strength of the titanium alloy avoids the difficult problem that the brittleness of the alloy is improved due to the fact that Mo is added to promote the formation of a Laves phase in the aging process; by adding Ta, the titanium alloy surface layer in the boiling concentrated nitric acid forms TiO with higher chemical stability₂And Ta₂O₅The titanium alloy corrosion resistance is obviously improved due to the double oxide film structure; by adding Al and controlling the content of Al, the method inhibits the metastable beta phase from decomposing to generate omega phase to initiate brittleness, further ensures the full play of the strengthening effect of the second phase, and further improves the strength and the corrosion resistance of the titanium alloy.

The 1200 MPa-level nitric acid corrosion resistant high-strength titanium alloy is characterized in that the mass content of the inevitable impurities is not more than 0.1%. The invention reduces the effect of impurities on the plasticity deterioration of the titanium alloy by controlling the content of the impurities in the titanium alloy, and is beneficial to ensuring the performance of the titanium alloy.

In addition, the invention also provides a method for preparing the 1200MPa nitric acid corrosion resistant high-strength titanium alloy, which is characterized by comprising the following steps:

step one, preparing raw materials according to design components of a target product titanium alloy, and then smelting to prepare a titanium alloy ingot; the Ta element in the target product titanium alloy is added by taking Ti-Ta intermediate alloy as a raw material, and the V element and the Al element are added by taking V-Al intermediate alloy as a raw material;

step two, forging the titanium alloy ingot obtained in the step one to obtain a titanium alloy forging;

and step three, carrying out heat treatment on the titanium alloy forging obtained in the step two to obtain the 1200 MPa-level nitric acid corrosion resistant high-strength titanium alloy.

The method is characterized in that the titanium alloy forged piece obtained in the step two is subjected to hot rolling to obtain a titanium alloy rolled piece, and then the titanium alloy rolled piece is subjected to heat treatment in the step three to obtain the 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy.

The method is characterized in that the smelting method in the step one is a vacuum consumable arc smelting method, a non-consumable vacuum arc furnace smelting method, a cold hearth smelting method, a cold crucible smelting method and an electroslag smelting method. The smelting method for preparing the titanium alloy ingot is various, the conventional ingot preparation method is covered, and the practical value of the method is improved.

The method described above, wherein the number of fire cycles of the forging in the second step is not less than three. According to the invention, the heating number of forging is controlled to be not less than three times, so that the structure homogenization and refinement of the titanium alloy forging are realized while the forging deformation is realized, and the high strength performance of the titanium alloy is ensured.

The method is characterized in that the forging in the step two comprises cogging forging, intermediate forging and finished product forging, the cogging forging temperature is not lower than 1100 ℃, the intermediate forging temperature is 900-950 ℃, the intermediate forging temperature is not lower than 1 time, and the finished product forging temperature is 780-820 ℃. The as-cast structure in the titanium alloy ingot is thick and uneven, the forging deformation resistance of the titanium alloy forging is reduced by adopting the cogging forging temperature of not less than 1100 ℃, cracking in the titanium alloy forging process is inhibited, the as-cast structure is broken, the internal structure is refined, and the plasticity is improved; then intermediate forging is carried out at 900-950 ℃, and the beta structure is thinned as much as possible on the premise of ensuring the plasticity of the titanium alloy forging; because the phase transition temperature of the titanium alloy is 740-760 ℃, the finished product forging is carried out at the temperature 20-60 ℃ higher than the phase transition temperature, on one hand, the titanium alloy forged piece after final forging is ensured to be a uniform beta single-phase structure, on the other hand, the beta structure can be refined to the maximum degree by forging in a low-temperature area of a beta phase region, and the strength of the titanium alloy is improved.

The method is characterized in that the titanium alloy rolled piece in the third step is a plate, a bar, a pipe or a wire.

The method is characterized in that the hot rolling temperature in the third step is 780-820 ℃. The hot rolling temperature ensures that the titanium alloy rolled piece obtained after hot rolling is a uniform beta single-phase structure, the beta structure is refined to the maximum extent, and the strength of the titanium alloy is further improved.

The method is characterized in that the heat treatment process comprises the following steps: firstly carrying out solid solution, air cooling or quenching to room temperature, then carrying out aging, air cooling or quenching to room temperature; the solid solution temperature is 760-800 ℃, the solid solution time is less than 1h, the aging temperature is 460-490 ℃, and the aging time is not less than 5 h. According to the invention, the rapid coarsening of the beta structure in the titanium alloy is avoided by controlling the solid solution temperature and time, the alpha phase precipitation amount in the titanium alloy reaches the peak value and the precipitated phase size is small by controlling the aging temperature, the complete precipitation of the precipitated phase is ensured by combining with the control of the aging time, and the optimization of the performance of the titanium alloy is realized.

Compared with the prior art, the invention has the following advantages:

1. the titanium alloy of the invention promotes Cr by adding Cr element and Ta element₂Ta and Cr₂Ti phase is precipitated together with alpha phase to play the role of precipitation strengthening, the strength of the titanium alloy is improved, and Ta is added to promote the titanium alloy surface layer to form TiO₂And Ta₂O₅The titanium alloy corrosion resistance is obviously improved by the double oxide film structure, the high-strength corrosion-resistant titanium alloy with tensile strength of more than 1200MPa and good plasticity and corrosion resistance is obtained, and the problems that the corrosion-resistant titanium alloy for the current post-treatment industry is insufficient in strength and the corrosion resistance of the high-strength titanium alloy generally does not meet the post-treatment working condition are solved.

2. According to the invention, the V element is added to replace Mo to perform solid solution strengthening so as to improve the strength of the titanium alloy, the difficult problem that the addition of Mo promotes the formation of Laves phase in the aging process to cause the improvement of alloy brittleness is avoided, and meanwhile, the strength and corrosion resistance of the titanium alloy are further improved by controlling the addition amount of Al.

3. In the preparation method, Ti-Ta intermediate alloy is adopted as a Ta element raw material for smelting, so that the distribution uniformity of the high-melting-point Ta element in the titanium alloy ingot is greatly improved.

4. According to the invention, through solid solution in a low-temperature zone of a beta phase zone, the residual stress of the alloy in a hot rolling state is eliminated, the uniformity of the structure is improved, and fine and dispersed precipitated phases are obtained by accurately controlling the aging temperature, so that the titanium alloy with good matching of strong plasticity performance is obtained.

The technical solution of the present invention is further described in detail by examples below.

Detailed Description

Example 1

The 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy comprises the following components in percentage by mass: 4.5 percent of Ta4, 4.5 percent of V, 7.5 percent of Cr7, 1.0 percent of Al0 percent, and the balance of Ti and inevitable impurities, wherein the mass content of the inevitable impurities is not more than 0.1 percent.

The preparation method of the 1200MPa nitric acid corrosion resistant high-strength titanium alloy comprises the following steps:

step one, preparing raw materials including 0-grade sponge titanium, Ti-40% Ta intermediate alloy, Al-85% V intermediate alloy and electrolytic Cr according to the designed nominal composition Ti-4.5Ta-4.5V-7.5Cr-1Al of a target product titanium alloy, then uniformly mixing the raw materials, pressing the raw materials into electrode rods by using an oil press, welding the electrode rods in groups by using plasma welding, and then placing the electrode rods in a vacuum consumable arc melting furnace for three times of vacuum consumable arc melting to prepare 30kg of titanium alloy cast ingots;

step two, peeling the titanium alloy ingot obtained in the step one by adopting a lathe, cutting off a casting riser by using a sawing machine, cogging and forging the titanium alloy ingot at 1120 ℃ by adopting a hydraulic forging machine, performing intermediate forging at 950 ℃ with two heats, performing three-heat forging at 900 ℃, performing finished product forging at 780 ℃, polishing the surface of a forging piece after each heat of forging, and removing defects such as surface scale, cracks and the like to obtain a titanium alloy bar with the diameter multiplied by the length of 50mm multiplied by Lmm;

step three, carrying out hot rolling on the titanium alloy bar obtained in the step two by adopting a bar mill at 780 ℃ to obtain a titanium alloy bar with the diameter of 15 mm;

and step four, carrying out solid solution on the titanium alloy bar obtained in the step three by adopting a muffle furnace at 760 ℃, wherein the solid solution time is 0.8h, carrying out air cooling to room temperature, then carrying out aging at 460 ℃, wherein the aging time is 6h, and carrying out air cooling to room temperature to obtain the titanium alloy.

Through detection, the tensile strength of the titanium alloy prepared by the method is 1479MPa, the yield strength is 1409MPa, the elongation is 6.5%, and the corrosion rate under 6mol of boiling nitric acid is less than 0.03mm/a (240 h).

The smelting method in the first step of this embodiment may also be replaced by a non-consumable vacuum arc furnace smelting method, a cold hearth smelting method, a cold crucible smelting method, or an electroslag smelting method.

The titanium alloy rolled piece in the third step of the embodiment can also be a titanium alloy plate, tube or wire.

Example 2

The 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy comprises the following components in percentage by mass: ta5%, V5%, Cr8%, Al1.0%, and the balance of Ti and inevitable impurities, wherein the mass content of the inevitable impurities is not more than 0.1%.

The preparation method of the 1200MPa nitric acid corrosion resistant high-strength titanium alloy comprises the following steps:

step one, preparing raw materials including 0-grade sponge titanium, Ti-40% Ta intermediate alloy, Al-85% V intermediate alloy and electrolytic Cr according to the designed nominal composition Ti-5Ta-5V-8Cr-1Al of a target product titanium alloy, then uniformly mixing the raw materials, pressing the raw materials into electrode rods by using an oil press, performing group welding on the electrode rods by using plasma welding, and then placing the electrode rods in a vacuum consumable arc melting furnace for three times of vacuum consumable arc melting to prepare 30kg of titanium alloy cast ingots;

step two, peeling the titanium alloy ingot obtained in the step one by adopting a lathe, cutting off a casting riser by using a sawing machine, cogging and forging the titanium alloy ingot at 1120 ℃ by adopting a hydraulic forging machine, performing intermediate forging at 950 ℃ with two heats, performing three-heat forging at 900 ℃, performing finished product forging at 780 ℃, polishing the surface of a forging piece after each heat of forging, and removing defects such as surface scale, cracks and the like to obtain a titanium alloy bar with the diameter of 200 mm;

step three, hot rolling the titanium alloy bar obtained in the step two by using a hot rolling pipe mill at 790 ℃ to obtain a titanium alloy bar with the diameter of 50mm and the wall thickness of 10 mm;

and step four, carrying out solid solution on the titanium alloy bar obtained in the step three by adopting a muffle furnace at 760 ℃, wherein the solid solution time is 0.7h, carrying out air cooling to room temperature, then carrying out aging at 475 ℃, wherein the aging time is 5.5h, and carrying out air cooling to room temperature to obtain the titanium alloy.

Through detection, the tensile strength of the titanium alloy prepared by the method is 1450MPa, the yield strength is 1395MPa, the elongation is 7%, and the corrosion rate under 6mol of boiling nitric acid is less than 0.03mm/a (240 h).

The smelting method in the first step of this embodiment may also be replaced by a non-consumable vacuum arc furnace smelting method, a cold hearth smelting method, a cold crucible smelting method, or an electroslag smelting method.

The titanium alloy rolled piece in the third step of the embodiment can also be a titanium alloy plate, tube or wire.

Example 3

The 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy comprises the following components in percentage by mass: 5.5 percent of Ta5%, 5.5 percent of V, 8.5 percent of Cr8, 1.5 percent of All, and the balance of Ti and inevitable impurities, wherein the mass content of the inevitable impurities is not more than 0.1 percent.

The preparation method of the 1200MPa nitric acid corrosion resistant high-strength titanium alloy comprises the following steps:

step one, preparing raw materials including 0-grade sponge titanium, Ti-40% Ta intermediate alloy, Al-85% V intermediate alloy and electrolytic Cr according to the designed nominal composition Ti-5.5Ta-5.5V-8.5Cr-1.5Al of a target product titanium alloy, then uniformly mixing the raw materials, pressing the raw materials into electrode rods by using an oil press, performing group welding on the electrode rods by using plasma welding, and then placing the electrode rods in a vacuum consumable arc melting furnace for performing three times of vacuum consumable arc melting to prepare 30kg of titanium alloy cast ingots;

step two, peeling the titanium alloy ingot obtained in the step one by adopting a lathe, cutting off a casting riser by using a sawing machine, cogging and forging the titanium alloy ingot at 1100 ℃, performing intermediate forging at 900 ℃ with two fires, performing finished product forging at 820 ℃ with three fires, polishing the surface of the forged piece after each fire forging, and removing the defects of surface scale, cracks and the like to obtain a titanium alloy square forged piece with the width multiplied by the height multiplied by the length of 150mm multiplied by Lmm;

step three, hot rolling the titanium alloy square forging obtained in the step two by adopting a plate rolling mill at 820 ℃ to obtain a titanium alloy plate with the thickness of 10 mm;

and step four, carrying out solid solution on the titanium alloy bar obtained in the step three by adopting a muffle furnace at 800 ℃, wherein the solid solution time is 0.5h, quenching to room temperature, then carrying out aging at 490 ℃, wherein the aging time is 5h, and quenching to room temperature to obtain the titanium alloy.

The titanium alloy prepared by the method has the tensile strength of 1335MPa, the yield strength of 1268MPa, the elongation of 10 percent and the corrosion rate of less than 0.035mm/a (240 h) under 6mol of boiling nitric acid.

The smelting method in the first step of this embodiment may also be replaced by a non-consumable vacuum arc furnace smelting method, a cold hearth smelting method, a cold crucible smelting method, or an electroslag smelting method.

The titanium alloy rolled piece in the third step of the embodiment can also be a titanium alloy bar, a pipe or a wire.

Example 4

The 1200 MPa-grade nitric acid corrosion resistant high-strength titanium alloy comprises the following components in percentage by mass: 5.5 percent of Ta5%, 5.5 percent of V, 8.5 percent of Cr8, 1.5 percent of Al, and the balance of Ti and inevitable impurities, wherein the mass content of the inevitable impurities is not more than 0.1 percent.

The preparation method of the 1200MPa nitric acid corrosion resistant high-strength titanium alloy comprises the following steps:

step one, preparing raw materials including 0-grade sponge titanium, Ti-40% Ta intermediate alloy, Al-85% V intermediate alloy and electrolytic Cr according to the designed nominal composition Ti-5.5Ta-5.5V-8.5Cr-1.5Al of a target product titanium alloy, then uniformly mixing the raw materials, pressing the raw materials into electrode rods by using an oil press, performing group welding on the electrode rods by using plasma welding, and then placing the electrode rods in a vacuum consumable arc melting furnace for performing three times of vacuum consumable arc melting to prepare 30kg of titanium alloy cast ingots;

step two, peeling the titanium alloy ingot obtained in the step one by adopting a lathe, cutting off a casting riser by using a sawing machine, cogging and forging the titanium alloy ingot at 1100 ℃, carrying out intermediate forging at 900 ℃ with two fires, carrying out intermediate forging at 870 ℃, carrying out finished product forging at 820 ℃ with four fires, polishing the surface of the forged piece after each fire of forging, and removing the defects of surface scale, cracks and the like to obtain a titanium alloy plate-shaped forged piece with the width multiplied by the thickness multiplied by the length of 150mm multiplied by 30mm multiplied by Lmm;

and step three, carrying out solid solution on the titanium alloy plate-shaped forging obtained in the step three at 780 ℃ by using a muffle furnace, quenching to room temperature for 0.5h, then carrying out aging at 460 ℃, wherein the aging time is 6h, and quenching to room temperature to obtain the titanium alloy.

The titanium alloy prepared by the method has the tensile strength of 1385MPa, the yield strength of 1295MPa, the elongation of 6 percent and the corrosion rate of less than 0.03mm/a (240 h) under 6mol of boiling nitric acid through detection.

The smelting method in the first step of this embodiment may also be replaced by a non-consumable vacuum arc furnace smelting method, a cold hearth smelting method, a cold crucible smelting method, or an electroslag smelting method.

The titanium alloy plate in the second step of this embodiment may also be a titanium alloy tube, a bar or a wire.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.