High-strength wear-resistant titanium alloy and preparation method thereof

Abstract

The invention discloses a high-strength wear-resistant titanium alloy and a preparation method thereof. The high-strength wear-resistant titanium alloy comprises the following components in percentage by mass: 2.7%-3.2% of Al, 4.8%-5.2% of V, 5.0%-5.8% of Mo, 6.6%-7.2% of Cr, 0.8%-1.2% of Zr, 1.3%-1.6% of Fe, less than or equal to 0.07% of O, less than or equal to 0.012% of N, less than or equal to 0.04% of H, less than or equal to 0.08% of C and the balance of Ti and inevitable impurity elements. According to the method, a'high-low-high 'multi-temperature zone repeated upsetting and drawing means is adopted, so that the internal structure of the high-strength wear-resistant titanium alloy cast ingot is effectively refined, and the beta grain size of the edge and the core part is reduced; alloy grains fully grow up and diffuse through internal stress relief annealing treatment, the problem that a large-section cast ingot forging stock structure is thick and uneven is effectively solved, the comprehensive mechanical property of the novel high-strength wear-resistant titanium alloy is improved, the cost is low, and the method can be used for large-scale production and preparation.

Description

Technical Field

[0001] The present invention relates to the fields of materials and metallurgy, and more particularly to a high-strength wear-resistant titanium alloy and a preparation method thereof. Background Art

[0002] High-strength titanium alloys, with their excellent corrosion resistance and low density, are widely used in various scientific and technological fields, including aerospace, marine engineering, medical devices, and military applications. They are crucial for reducing the weight of metal structural components such as aircraft, cutting tools, and valves. my country's demand for high-strength and wear-resistant titanium alloys is primarily for the production of naval diving knives, which require an HRC hardness of 50 or higher. Currently, conventional high-strength titanium alloys after annealing exhibit HRC hardness values ​​of TC4 < 40, TB5 < 45, and TB2 < 48, which fall short of the technical hardness requirements for naval diving knives. In recent years, to ensure rapid technological advancements and meet the demand for lightweight, high-strength titanium alloys in advanced industries, both domestically and internationally, efforts have been focused on developing new high-strength titanium alloys with stable service performance. However, the hardness of conventional high-strength titanium alloys after annealing is insufficient to meet the high hardness requirements of naval diving knives.

[0003] It is well known that the factors that affect the forming of titanium alloy products include low thermal conductivity, high deformation resistance, poor heat resistance, and sensitivity to temperature parameters. Therefore, the requirements for the preparation process and application environment are very stringent. When preparing high-strength and wear-resistant titanium alloy ingots, coarse β grains are often produced inside the organization due to the excessively rapid cooling and solidification rate, resulting in chemical composition segregation, which is not conducive to the subsequent development of titanium alloy products. In addition, since high-strength titanium alloys contain more expensive alloy raw materials containing β-stabilizing elements, the production and manufacturing costs of high-strength and wear-resistant titanium alloys need to be comprehensively considered during the research and development process. In addition, the current titanium alloy forging temperature range is relatively narrow. When the forging load is large, it is easy to overheat locally, and the deformation and microstructure distribution are uneven, which can easily cause cracks on the surface of the forging. Therefore, it is difficult to fully utilize the plasticity of the alloy using conventional forging methods, and it is difficult to forge more complex parts.

[0004] Patent CN106011537A discloses a fine-grained, high-strength and toughness β-titanium alloy and its production method. The focus is on obtaining a forging blank through two rounds of isothermal die forging, followed by solution aging treatment to optimize the alloy's strength, toughness, and plasticity. In the first round of die forging, only one round of multi-directional forging is performed. The cooling rate at the edges of the forging material is too rapid, making cracking very likely to occur. Furthermore, the grain growth of each phase within the forging material is uneven, hindering subsequent product development. Patent CN103243235A discloses a high-strength titanium alloy. The high-strength titanium alloy produced by this method exhibits poor room-temperature mechanical properties, with a tensile strength ≥1100 MPa and a plasticity ≥15%, hindering the long-term development of titanium alloy product applications. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a high-strength and wear-resistant titanium alloy and a preparation method thereof. The invention adopts a "high-low-high" multi-temperature zone repeated upsetting method to effectively refine the internal structure of the high-strength and wear-resistant titanium alloy ingot and reduce the size of the β grains at the edge and the core; and through internal stress relief annealing treatment, the alloy grains are fully grown and diffused, effectively solving the problem of coarse and uneven structure of large-section ingot forgings and improving the comprehensive mechanical properties of the new high-strength and wear-resistant titanium alloy. The process is simple, the production cost is low, and it can be used for large-scale production.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A high-strength wear-resistant titanium alloy comprises the following components in percentage by mass: Al: 2.7%-3.2%, V: 4.8%-5.2%, Mo: 5.0%-5.8%, Cr: 6.6%-7.2%, Zr: 0.8%-1.2%, Fe: 1.3%-1.6%, O≤0.07%, N≤0.012%, H≤0.04%, C≤0.08%, and the balance is Ti and unavoidable impurity elements.

[0008] Optionally, the relative ranges of the mass percentages of Al, V, Mo, Cr, Fe and Zr in the high-strength wear-resistant titanium alloy are 0.5% to 1.0% respectively, and the phase transition point T β The temperature is 830℃~870℃, the tensile strength is ≥1200MPa, the yield strength is ≥1100MPa, the elongation is 11%~13%, HRC ≥51, and the diameter of the β grain is 10μm~30μm.

[0009] The present invention also discloses a method for preparing the high-strength wear-resistant titanium alloy as described above, comprising the following steps:

[0010] (1) weighing a master alloy and a titanium sponge raw material according to the element ratio of the high-strength wear-resistant titanium alloy, mixing the master alloy and the titanium sponge raw material to press a plurality of electrode blocks, and welding the plurality of electrode blocks to obtain a consumable electrode;

[0011] (2) welding the consumable electrode to the auxiliary electrode and then performing vacuum consumable melting three times to obtain an alloy ingot;

[0012] (3) grinding and trimming the ingot, and then forging the obtained billet to obtain a forging;

[0013] (4) In T β -70℃~T β The forging is subjected to internal stress relief annealing treatment in a temperature range of -30°C to obtain the high-strength and wear-resistant titanium alloy.

[0014] Optionally, in step (1), the raw materials are sponge titanium, vanadium-aluminum alloy, molybdenum-iron alloy, titanium-molybdenum alloy, zirconium sponge, aluminum beans, and elemental metal chromium alloy; the sponge titanium is military-grade small-grain A0 grade ultra-soft sponge titanium; and the mixing time is 10 min to 20 min.

[0015] Optionally, in step (2), the three vacuum consumable melting processes include: vacuum degree ≤ 1.0 Pa, current of 2.5 kA to 4.0 kA, voltage of 20 V to 35 V, temperature of 1600° C. to 2000° C., and time of 2 h to 5 h; and the welding method is manual argon arc welding.

[0016] Optionally, in step (3), the size of the blank is φ200mm×400mm.

[0017] Optionally, in step (3), the forging includes the following steps:

[0018] The alloy ingot is subjected to open forging, kept at 900° C. to 1100° C. for 2 to 3 hours, and after being taken out of the furnace, subjected to repeated upsetting and drawing forging for 1 to 2 times to obtain a primary forging blank;

[0019] The primary forging blank is placed at T β -60℃~T β Keeping the temperature at -50℃ for 0.5h to 2h, and then repeatedly performing upsetting and drawing forging for 3 to 4 times to obtain the second forging blank;

[0020] The second forging blank is placed at T β -20℃~T β The forging is kept at -10°C for 0.5 to 2 hours, and then subjected to repeated upsetting and drawing forging for 1 to 2 times to obtain the forged piece.

[0021] Optional, in the high temperature range of 900℃~1100℃, T β -20℃~T β The single upsetting deformation within -10℃ is ≤20%, and the low temperature range T β -60℃~T β The deformation of a single upsetting and drawing process within -50°C is ≤15%, and the cumulative total deformation is ≤85%. During the forging process, the material starting time is ≤10s, and the time for transporting the material to the forging machine is ≤50s. After the final forging, water quenching is performed immediately, and the transport time is ≤30s.

[0022] Optionally, in step (4), the stress relief annealing includes: a solution temperature of 800°C to 840°C, a solution time of 1h to 3h, furnace cooling to 600°C to 640°C and keeping warm for 1h to 2h, and air cooling to room temperature after being taken out of the furnace.

[0023] The implementation of the present invention will have the following beneficial effects:

[0024] 1. The present invention prepares a new type of high-strength and wear-resistant titanium alloy, combines the "high-low-high" reforming technology with the annealing process, focuses on optimizing and controlling the forging process parameters, and uses multiple remelting and heat preservation passes to ensure the macroscopic surface of the forging product, thereby refining the grains, uniformizing the structure and improving its comprehensive mechanical properties, effectively solving the problems of coarse ingot grains and uneven structure. The production method is simple, low-cost and high-tech.

[0025] 2. The high-strength wear-resistant titanium alloy forging products prepared by the present invention have relative extreme differences in the mass percentage of the main elements Al, V, Mo, Cr, Fe, and Zr, respectively, of 0.5% to 1.0%, and the phase transition point T β The temperature is 830℃~870℃, the tensile strength is ≥1200MPa, the yield strength is ≥1100MPa, the elongation is 11%~13%, HRC ≥51, and the diameter of β grains is 10μm~30μm, which meets the application requirements of high-precision fields such as aerospace, naval cutting tools, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a microstructural morphology of the high-strength wear-resistant alloy ingot after annealing in Example 4 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to specific examples, but the present invention is not limited thereto in any way.

[0028] Example 1

[0029] The high-strength wear-resistant titanium alloy of this embodiment includes the following components by mass percentage: Al: 3.0%, V: 5.2%, Mo: 5.8%, Cr: 6.6%, Zr: 1.1%, Fe: 1.6%, O: 0.04%, N: 0.01%, H: 0.02%, C: 0.04%, and the balance is Ti and unavoidable impurity elements. The relative difference in the mass percentage of Al, V, Mo, Cr, Fe, and Zr in the high-strength wear-resistant titanium alloy is 0.6%. The phase transition point T of the alloy of this embodiment is measured by metallographic method. β The temperature is 860℃~870℃, and the ingot forging test is carried out after grinding. The diameter of the refined β grains is 10μm~20μm.

[0030] The method for preparing the high-strength wear-resistant titanium alloy of this embodiment comprises the following steps:

[0031] (1) According to the element ratio of high-strength wear-resistant titanium alloy, military-grade small-grain A0 grade super-soft sponge titanium, 55VAl, molybdenum-iron alloy and titanium-molybdenum alloy are weighed, and the auxiliary materials are sponge zirconium, aluminum beans and elemental metal chromium alloy. The intermediate alloy and sponge titanium raw materials are mixed and pressed into multiple electrode blocks, and the multiple electrode blocks are welded to obtain consumable electrodes.

[0032] (2) After connecting the consumable electrode and the auxiliary electrode by manual argon arc welding, three vacuum consumable melting processes were carried out with a vacuum degree of ≤1.0Pa. At the beginning of the melting process, the current was 2.5kA to 4.0kA. In the middle and late stages of the melting process, the current was stably controlled at 3.3kA, the voltage was 30V, the temperature was 1600℃ to 2000℃, and the melting time was 4h. After grinding and cutting, a high-strength and wear-resistant titanium alloy ingot of 130 to 140kg was obtained.

[0033] (3) The ingot is polished and trimmed to obtain a billet with a size of φ200 mm×400 mm. The temperature change of each forging fire is a "high-low-high" trend, and the alloy forging is prepared by a multi-temperature zone multi-fire repeated upsetting method. The forging includes the following steps:

[0034] (3.1) Preparation of the initial forging billet: The temperature is raised to 1000℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0035] (3.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and to avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 820°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 15%. Second and third forging cycles: Hold at 820°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 15%.

[0036] (3.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 840℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 15%; the second fire: keep warm at 840℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0037] (4) The forgings were subjected to stress relief annealing at a solution temperature of 840°C for 2 hours. The forgings were then furnace cooled to 500°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1559 MPa, a yield strength of 1433 MPa, an elongation of 11.2%, and an HRC of 52.4.

[0038] Example 2

[0039] The alloy ingot composition design ratio and smelting method involved in this embodiment are the same as those in Example 1, and the alloy forgings are produced by the multi-temperature zone multi-fire repeated upsetting method of Example 1. The forging method includes the following steps:

[0040] (1.1) Preparation of the initial forging billet: The temperature is raised to 1000℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0041] (1.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 810°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 10%. Second and third forging cycles: Hold at 810°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 10%.

[0042] (1.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 850℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 20%; the second fire: keep warm at 850℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0043] (2) The forgings were subjected to stress relief annealing at a solution temperature of 840°C for 2 hours. The forgings were then furnace-cooled to 500°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1518 MPa, a yield strength of 1390 MPa, an elongation of 12.1%, and an HRC of 52.1.

[0044] Example 3

[0045] The alloy ingot composition design ratio and smelting method involved in this embodiment are the same as those in Example 1, and the alloy forgings are produced by the multi-temperature zone multi-fire repeated upsetting method of Example 1. The forging method includes the following steps:

[0046] (1.1) Preparation of the initial forging billet: The temperature is raised to 1000℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0047] (1.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 800°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 10%. Second and third forging cycles: Hold at 800°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 10%.

[0048] (1.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 860℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 20%; the second fire: keep warm at 860℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0049] (2) The forgings were subjected to stress relief annealing at a solution temperature of 840°C for 2 hours. The forgings were then furnace-cooled to 500°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1461 MPa, a yield strength of 1310 MPa, an elongation of 12.8%, and an HRC of 51.7.

[0050] Example 4

[0051] The difference between the mass percentage composition of the high-strength wear-resistant titanium alloy of this embodiment and that of Examples 1 to 3 is that the Mo content is 5.4%, the Cr content is 6.9%, and the proportions of other elements are the same. Similarly, the relative difference in the mass percentage of Al, V, Mo, Cr, Fe, and Zr in the alloy is 0.6%. The phase transition point T of the alloy of this embodiment is measured by metallographic method. β The temperature is 860℃~870℃, and the ingot forging test is carried out after grinding. The diameter of the refined β grain is 30μm~40μm.

[0052] This embodiment adopts the multi-temperature zone multi-fire repeated upsetting method involved in Examples 1 to 3 to produce alloy forgings, including the following steps:

[0053] (1.1) Preparation of the initial forging billet: The temperature is raised to 900℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0054] (1.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 820°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 15%. Second and third forging cycles: Hold at 820°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 15%.

[0055] (1.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 840℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 15%; the second fire: keep warm at 840℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0056] (2) The forgings were subjected to stress relief annealing at a solution temperature of 820°C for 2 hours. The forgings were then furnace cooled to 550°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1520 MPa, a yield strength of 1498 MPa, an elongation of 12.2%, and an HRC of 51.9.

[0057] Example 5

[0058] The alloy ingot composition design ratio and smelting method involved in this embodiment are the same as those in Example 4. The forging method comprises the following steps:

[0059] (1.1) Preparation of the initial forging billet: The temperature is raised to 900℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0060] (1.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 810°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 10%. Second and third forging cycles: Hold at 810°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 10%.

[0061] (1.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 850℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 20%; the second fire: keep warm at 850℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0062] (2) The forgings were subjected to stress relief annealing at a solution temperature of 820°C for 2 hours. The forgings were then furnace cooled to 550°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1456 MPa, a yield strength of 1302 MPa, an elongation of 12.7%, and an HRC of 51.4.

[0063] Example 6

[0064] The alloy ingot composition design ratio and smelting method involved in this embodiment are the same as those in Example 4. The forging method comprises the following steps:

[0065] (1.1) Preparation of the initial forging billet: The temperature is raised to 900℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of upsetting and drawing, with a deformation of 20%.

[0066] (1.2) Preparation of the Second Forging Billet: To ensure uniform microstructure of the alloy forgings and avoid surface overcooling and core overheating of the large forging billet, the intermediate forging billet should be immediately transferred to the furnace after each upsetting and drawing cycle. First forging cycle: Hold at 800°C for 1 hour, transfer to the forging press within 50 seconds, perform two upsetting and two drawing cycles, and achieve a deformation of 10%. Second and third forging cycles: Hold at 800°C for 0.5 hour, transfer to the forging press within 50 seconds, perform one upsetting and one drawing cycle, and achieve a deformation of 10%.

[0067] (1.3) The final forgings are prepared by a two-fire upsetting and drawing method: the first fire: keep warm at 860℃ for 1 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and the deformation is 20%; the second fire: keep warm at 860℃ for 0.5 hour, transfer to the forging machine within 50 seconds, perform one upsetting and one drawing, and then immediately water quench within 30 seconds to obtain the final forging product.

[0068] (2) The forgings were subjected to stress relief annealing at a solution temperature of 820°C for 2 hours. The forgings were then furnace cooled to 550°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1410 MPa, a yield strength of 1296 MPa, an elongation of 11.5%, and an HRC of 51.6.

[0069] Comparative Example 1

[0070] The alloy ingot composition design ratio and smelting method involved in this comparative example are the same as those in Example 1. The forging method adopted includes the following steps:

[0071] (1.1) Preparation of the initial forging billet: The temperature is raised to 1100°C in the furnace and kept at this temperature for 2 hours. The ingot is manually transferred to the forging machine within 50 seconds for the first round of two upsetting and two drawing, with a deformation of 30%.

[0072] (1.2) Preparation of the Second Forging Billet: Upset both ends, grind the billet surface, and chamfer the edges and corners. After each upsetting and drawing cycle, transfer the intermediate forging billet to the furnace immediately. Hold at 1050°C for 2 hours, then perform two upsetting and two drawing cycles, with a deformation of 30%.

[0073] (1.3) Preparation of final forgings: Keep the temperature at 1000℃ for 1 hour, perform one upsetting and one drawing, rolling and drawing, with a deformation of 20%, and water quench within 30 seconds to obtain the final forging products.

[0074] (2) The forgings were subjected to stress relief annealing at a solution temperature of 840°C for 2 hours. The forgings were then furnace-cooled to 500°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy exhibited a tensile strength of 1321 MPa, a yield strength of 1150 MPa, an elongation of 8.6%, and an HRC of 49.4.

[0075] Comparative Example 2

[0076] The alloy ingot composition design ratio and smelting method involved in this comparative example are the same as those in Example 4. The forging method adopted includes the following steps:

[0077] (1.1) Preparation of the initial forging billet: The temperature is raised to 1000℃ in the furnace and kept at this temperature for 2 hours. The ingot is manually clamped and transferred to the forging machine within 50 seconds for the first round of two upsetting and two drawing, with a deformation of 30%.

[0078] (1.2) Preparation of the Second Forging Billet: Upset both ends, grind the billet surface, and chamfer the edges and corners. After each upsetting and drawing cycle, transfer the intermediate forging billet to the furnace immediately. Hold at 950°C for 2 hours, then perform two upsetting and two drawing cycles, with a deformation of 30%.

[0079] (1.3) Preparation of final forgings: Keep the temperature at 900℃ for 1 hour, perform one upsetting and one drawing, rolling and drawing, with a deformation of 20%, and water quench within 30 seconds to obtain the final forging products.

[0080] (2) The forgings were subjected to stress relief annealing at a solution temperature of 820°C for 2 hours. The forgings were then furnace cooled to 550°C and held for 1 hour. The forgings were then air-cooled to room temperature to obtain a high-strength, wear-resistant titanium alloy. Mechanical property testing revealed that the alloy in this example had a tensile strength of 1278 MPa, a yield strength of 1084 MPa, an elongation of 9.1%, and an HRC of 48.7.

[0081] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A high-strength wear-resistant titanium alloy, characterized in that: Includes the following components in percentage by mass: Al: 2.7%~3.2%, V: 4.8%~5.2%, Mo: 5.0%~5.8%, Cr: 6.6%~7.2%, Zr: 0.8%~1.2%, Fe: 1.3%~1.6%, O≤0.07%, N≤0.012%, H≤0.04%, C≤0.08%, and the balance is Ti and unavoidable impurity elements.

2. The high-strength wear-resistant titanium alloy according to claim 1, characterized in that: The relative range of the mass percentage of Al, V, Mo, Cr, Fe and Zr in the high-strength wear-resistant titanium alloy is 0.5% to 1.0%, and the phase transition point T β The temperature is 830℃~870℃, the tensile strength is ≥1200MPa, the yield strength is ≥1100MPa, the elongation is 11%~13%, HRC ≥51, and the diameter of the β grain is 10μm~30μm.

3. A method for preparing a high-strength wear-resistant titanium alloy according to any one of claims 1 to 2, characterized in that: The following steps are involved: (1) weighing a master alloy and a titanium sponge raw material according to the element ratio of the high-strength wear-resistant titanium alloy, mixing the master alloy and the titanium sponge raw material to press a plurality of electrode blocks, and welding the plurality of electrode blocks to obtain a consumable electrode; (2) welding the consumable electrode to the auxiliary electrode and then performing vacuum consumable melting three times to obtain an alloy ingot; (3) grinding and trimming the ingot, and then forging the obtained billet to obtain a forging; (4) In T β -70℃~T β The forging is subjected to internal stress relief annealing treatment in a temperature range of -30°C to obtain the high-strength and wear-resistant titanium alloy.

4. The preparation method according to claim 3, characterized in that In step (1), the raw materials are sponge titanium, vanadium aluminum alloy, molybdenum iron alloy, titanium molybdenum alloy, sponge zirconium, aluminum beans, and elemental metal chromium alloy; the sponge titanium is military-grade small-grain A0 grade ultra-soft sponge titanium; and the mixing time is 10 min to 20 min.

5. The preparation method according to claim 3, characterized in that In step (2), the three vacuum consumable melting processes include: vacuum degree ≤ 1.0 Pa, current of 2.5 kA to 4.0 kA, voltage of 20 V to 35 V, temperature of 1600° C. to 2000° C., and time of 2 h to 5 h; and the welding method is manual argon arc welding.

6. The preparation method according to claim 3, characterized in that In step (3), the size of the blank is 7. The preparation method according to claim 3, characterized in that In step (3), the forging includes the following steps: The alloy ingot is subjected to blank forging, kept at 900° C. to 1100° C. for 2 h to 3 h, and after being taken out of the furnace, subjected to repeated upsetting and drawing forging for 1 to 2 times to obtain a primary forging blank; The primary forging blank is placed at T β -60℃~T β Keeping the temperature at -50℃ for 0.5h to 2h, and then repeatedly performing upsetting and drawing forging for 3 to 4 times to obtain the second forging blank; The second forging blank is placed at T β -20℃~T β The forging is kept at -10°C for 0.5 to 2 hours, and then subjected to repeated upsetting and drawing forging for 1 to 2 times to obtain the forged piece.

8. The preparation method according to claim 7, characterized in that At 900℃~1100℃, T β -20℃~T β Single upsetting deformation under -10℃ condition ≤20%, T β -60℃~T β Under -50℃ condition, the deformation of single upsetting is ≤15%, and the total deformation is ≤85%; During the forging, the material starting time is ≤10s, and the material transfer time to the forging machine is ≤50s; and the material is immediately water quenched after the final forging, and the transfer time is ≤30s.

9. The preparation method according to claim 3, characterized in that In step (4), the stress relief annealing includes: solution temperature of 800°C to 840°C, solution time of 1h to 3h, furnace cooling to 600°C to 640°C and keeping warm for 1h to 2h, and air cooling to room temperature after being taken out of the furnace.

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