Cr-containing near-alpha high-temperature titanium alloy with service temperature of 600 DEG C or above and smelting method and application of Cr-containing near-alpha high-temperature titanium alloy

Abstract

The invention discloses a Cr-containing near-alpha high-temperature titanium alloy with the service temperature being 600 DEG C or above. The titanium alloy comprises, by weight, 4.5%-6.5% of Al, 1.5%-4.5% of Sn, 2.0%-4.5% of Zr, 0.5%-3.0% of Mo, and the balance Ti. 0.2 to 0.5 percent of Si; 2.5%-4.5% of Cr, and impurity component lt; 0.1%, with the balance being Ti; the sum of the weight percentages of the components is 100%. The invention further discloses a smelting method and application of the high-temperature titanium alloy. The problems that the titanium alloy is poor in component uniformity, and the room-temperature performance of the obtained high-temperature titanium alloy is as follows: tensile strength gt; the tensile strength is 1200MPa, and the yield strength is gt; the ductility is gt under the pressure of 900 MPa; 6.0%; the high temperature of 650 DEG C is as follows: tensile strength gt; the pressure is 600 MPa, and the yield strength is gt; the ductility is gt under the pressure of 480 MPa; and 12.0%.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy materials, and in particular to a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C, a smelting method and application thereof. Background Art

[0002] Titanium metal is known as "space metal" and "ocean metal", and its reserves on Earth rank ninth. Titanium alloys have excellent properties, such as high specific strength, corrosion resistance, and non-magnetic properties. With the rapid development of aerospace in recent years, various types of aircraft have been continuously developing in the direction of high performance, long life and reliability, and higher and higher requirements have been put forward for the high temperature resistance of key component materials. Among them, high-temperature titanium alloys are considered to have excellent application prospects. The existing mature high-temperature titanium alloys mainly include Ti-1100 in the United States, IMI834 in the United Kingdom, BT36 in Russia, and Ti-60, Ti-600, and TG6 in China; but the main alloying elements of the existing high-temperature titanium alloys are Al, Sn, Zr, Si, Mo, etc., and the maximum service temperature is 600℃. However, with the rapid development of the aerospace field, it is no longer possible to meet the use requirements of higher temperatures, so it is very necessary to develop high-temperature titanium alloys with a service temperature of more than 600℃.

[0003] Compared with ordinary titanium alloys, high-temperature titanium alloys have a high degree of alloying, and some alloy elements, such as W, Mo, Nb, Ta, etc., have high melting points and are difficult to melt, resulting in poor uniformity of alloy ingots.

[0004] Vacuum induction melting technology is one of the most advanced and low-cost methods for melting alloys. This method uses continuous electromagnetic induction heating to rapidly heat up the raw materials and melt them, and through strong electromagnetic stirring in the melt, the overall composition and temperature of the melt are uniform.

[0005] Alloying element Cr can improve the high temperature oxidation resistance and corrosion resistance of titanium alloy. Therefore, how to design a Cr-containing near-α high temperature titanium alloy with a service temperature of more than 600°C and its smelting method can expand the further application of high temperature titanium alloy. Summary of the invention

[0006] The purpose of the present invention is to provide a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C and a smelting method and application thereof, aiming to improve the smelting effect of the Cr-containing near-α high-temperature titanium alloy and increase its service temperature to manufacture high-temperature titanium alloy products.

[0007] In order to achieve the purpose of the present invention, the technical solution adopted is:

[0008] A Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C, calculated by weight percentage, comprising the following components:

[0009] Al: 4.5-6.5%;

[0010] Sn: 1.5-4.5%;

[0011] Zr: 2.0-4.5%;

[0012] Mo: 0.5-3.0%;

[0013] Si: 0.2-0.5%;

[0014] Cr: 2.5-4.5%;

[0015] Impurity content <0.1%;

[0016] The remainder is Ti;

[0017] The sum of the weight percentages of the above components is 100%.

[0018] In a preferred embodiment of the present invention, the service temperature is 650° C. and above.

[0019] In a preferred embodiment of the present invention, H in the impurity components is less than 0.006% or N is less than 0.01%.

[0020] A smelting method for a Cr-containing near-α high-temperature titanium alloy having a service temperature of more than 600° C. comprises the following steps:

[0021] (1) Weighing

[0022] According to the composition ratio of the titanium alloy, the corresponding titanium sponge, aluminum block, metal element and master alloy are weighed and placed separately, decontaminated and dried for later use;

[0023] (2) Furnace loading

[0024] After the graphite crucible is placed in place and calibrated, the raw materials in step (1) are loaded into the crucible for smelting;

[0025] (3) Vacuuming

[0026] Close the furnace door and repeatedly evacuate the furnace until the vacuum degree is not less than 1*10 -3 Pa;

[0027] (4) Melting

[0028] Gradually increase the power of vacuum melting to no less than 3kw and maintain the power until the raw materials are completely melted;

[0029] (5) Homogenization

[0030] Adjust the melting power repeatedly within the power range of 2-3kw and stir until the alloy composition is uniform;

[0031] (6) After smelting, pouring

[0032] After smelting, the alloy melt is poured into a graphite crucible, the power is reduced to 0, and the titanium alloy ingot in the graphite crucible is taken out after the furnace is cooled to room temperature to obtain the titanium alloy ingot containing Cr near-α high-temperature titanium alloy with a service temperature of more than 600°C.

[0033] In a preferred embodiment of the present invention, the titanium sponge is 0A grade titanium sponge;

[0034] The aluminum block is an aluminum block with a purity of not less than 99.99%;

[0035] The metal element is zirconium sponge, and the zirconium sponge is industrial first-grade zirconium sponge;

[0036] The master alloy is any one or more of a TiSn alloy, an AlMo alloy, an AlSi alloy or an AlCr alloy.

[0037] In a preferred embodiment of the present invention, the drying is performed by placing the product in a muffle furnace at 100-200° C. for 10-12 hours for drying.

[0038] In a preferred embodiment of the present invention, the graphite crucible is placed in place and calibrated to be placed in a pouring position in the furnace, and the crucible used for smelting is turned over to calibrate the position of the graphite crucible used for pouring.

[0039] In a preferred embodiment of the present invention, the power of the vacuum melting is gradually increased based on 1 kW and maintained at intervals of 3-5 minutes.

[0040] In a preferred embodiment of the present invention, the repeatedly adjusting the smelting power within the power range of 2-3kw is to adjust the power within the power range of 2-3kw and maintain the interval for 3-5 minutes.

[0041] In a preferred embodiment of the present invention, the room temperature performance of the Cr-containing near-α high-temperature titanium alloy with a service temperature of 600° C. or above satisfies the following requirements: tensile strength>1200MPa, yield strength>900MPa, and elongation>6.0%;

[0042] At a high temperature not less than 650 degrees Celsius, the performance reaches a tensile strength>600MPa, a yield strength>480MPa, and an elongation>12.0%.

[0043] An application of a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C, wherein the application is to prepare blades for aircraft engines.

[0044] The beneficial effects of the present invention are:

[0045] The Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C prepared by the present invention has both room temperature performance and high-temperature performance. Vacuum induction melting ensures its composition uniformity. The high-temperature titanium alloy composition and its vacuum induction melting method are expected to be used in the preparation of aircraft engine blades.

[0046] Compared with the prior art, the present invention adds the Cr element which helps to improve the high-temperature oxidation resistance of the high-temperature titanium alloy on the basis of the traditional high-temperature titanium alloy basic Ti-Al-Sn-Zr-Mo-Si system. The performance of the alloy at 650°C can reach: tensile strength>600MPa, yield strength>480MPa, and elongation>12.0%.

[0047] Compared with the prior art, the smelting method of the present invention can be used to prepare high-temperature titanium alloy ingots with uniform composition and purity up to 99.99%.

[0048] Compared with the prior art and vacuum consumable arc furnace, the smelting method of the present invention does not require pressing and welding electrodes, thus avoiding the contamination of raw materials in the process. The method is particularly suitable for the smelting and preparation of alloy ingots with high alloying degree and high performance requirements, such as high-temperature titanium alloys, and has broad prospects for application in the preparation of aircraft engine blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a diagram of vacuum induction melting for preparing high-temperature titanium alloy according to the present invention.

[0050] Figure 2 The representative internal microstructure diagram of the high temperature titanium alloy prepared in Examples 1-3 of the present invention.

[0051] Figure 3 Representative internal microstructure diagrams of the high temperature titanium alloys prepared in Examples 4-6 of the present invention.

[0052] Figure 4 Representative internal microstructure diagrams of the high temperature titanium alloys prepared in Examples 7-9 of the present invention.

[0053] Figure 5 The representative internal microstructure diagram of the high temperature titanium alloy prepared in Comparative Examples 1-3 of the present invention.

[0054] Figure 6 The representative internal microstructure diagram of the high temperature titanium alloy prepared in Comparative Examples 4-6 of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following structure, the description of the known structure and technology is omitted to avoid unnecessary confusion of the concept of the present invention.

[0056] The technical solutions in the embodiments of the present invention are described clearly and completely below. In particular, the described embodiment is only one embodiment of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Examples 1-3

[0058] (1) Weighing

[0059] Within the composition range of the designed high-temperature titanium alloy shown in Table 1, weigh the corresponding 85.9% Ti, 5.00% Al, 2.35% Sn, 2.45% Zr, 1.00% Mo, 0.25% Si, and 3.05% Cr, and put them in different containers according to their types for later use. All raw materials are decontaminated and placed in a muffle furnace at 100-200°C for 10-12 hours for drying.

[0060] (2) Furnace loading

[0061] Place the graphite crucible in the pouring position of the furnace, turn over the crucible used for smelting to calibrate the position of the graphite crucible used for pouring, and then load the raw materials mentioned in step (1) into the crucible used for smelting.

[0062] (3) Vacuum after closing the furnace door

[0063] Close the furnace door and repeatedly evacuate the furnace 3 times to make the vacuum degree in the furnace reach 1*10 -3 Pa.

[0064] (4) Melting

[0065] Start smelting, increase the power to 1kw, keep it for 3 minutes; increase the power to 2kw, keep it for 3 minutes; increase the power to 3kw, keep it for 3 minutes, and maintain the power until the raw materials are completely melted; if the raw materials cannot be completely melted at this power, increase the power to 4kw until all the raw materials are completely melted.

[0066] (5) Homogenization

[0067] After all the raw materials are melted, keep the power at 3kw for 5 minutes, then reduce the power to 2kw and keep it for 5 minutes, then increase the power to 3kw and keep it for 5 minutes, repeat the above process of reducing and increasing the power 3 times, and make the alloy composition more uniform through the effect of electromagnetic stirring.

[0068] (6) After smelting, pouring

[0069] After smelting is completed, the molten alloy is poured into a graphite crucible, the power is reduced to 0, and the furnace is cooled to room temperature.

[0070] (7) After cooling to room temperature, the vacuum is broken, the furnace door is opened, and the titanium alloy ingot in the graphite crucible is taken out to obtain a titanium alloy ingot.

[0071] The chemical composition of high temperature titanium alloy is shown in Table 1, and the mechanical properties are shown in Table 2.

[0072] Table 1 Chemical composition of high temperature titanium alloy (wt.%)

[0073]

[0074]

[0075] Table 2 Mechanical properties of high temperature titanium alloys

[0076]

[0077] Embodiment 4-6

[0078] (1) Weighing

[0079] Within the composition range of the designed high-temperature titanium alloy shown in Table 2, 83.6% Ti, 5.50% Al, 2.50% Sn, 3.00% Zr, 1.55% Mo, 0.35% Si, and 3.50% Cr were weighed and placed in different containers according to their types for later use. All raw materials were decontaminated and placed in a muffle furnace at 100-200°C for 10-12 hours for drying.

[0080] (2) Furnace loading

[0081] Place the graphite crucible in the pouring position of the furnace, turn over the crucible used for smelting to calibrate the position of the graphite crucible used for pouring, and then load the raw materials mentioned in step (1) into the crucible used for smelting.

[0082] (3) Vacuum after closing the furnace door

[0083] Close the furnace door and repeatedly evacuate the furnace 3 times to make the vacuum degree in the furnace reach 1*10 -3 Pa.

[0084] (4) Melting

[0085] Start smelting, increase the power to 1kw, keep it for 3 minutes; increase the power to 2kw, keep it for 3 minutes; increase the power to 3kw, keep it for 3 minutes, and maintain the power until the raw materials are completely melted; if the raw materials cannot be completely melted at this power, increase the power to 4kw until all the raw materials are completely melted.

[0086] (5) Homogenization

[0087] After all the raw materials are melted, keep the power at 3kw for 5 minutes, then reduce the power to 2kw and keep it for 5 minutes, then increase the power to 3kw and keep it for 5 minutes, repeat the above process of reducing and increasing the power 3 times, and make the alloy composition more uniform through the effect of electromagnetic stirring.

[0088] (6) After smelting, pouring

[0089] After smelting is completed, the molten alloy is poured into a graphite crucible, the power is reduced to 0, and the furnace is cooled to room temperature.

[0090] (7) After cooling to room temperature, the vacuum is broken, the furnace door is opened, and the titanium alloy ingot in the graphite crucible is taken out to obtain a titanium alloy ingot.

[0091] The chemical composition of high temperature titanium alloy is shown in Table 3, and the mechanical properties are shown in Table 4.

[0092] Table 3 Chemical composition of high temperature titanium alloy (wt.%)

[0093]

[0094] Table 4 Mechanical properties of high temperature titanium alloys

[0095]

[0096] Embodiment 7-9

[0097] (1) Weighing

[0098] Within the composition range of the designed high temperature titanium alloy as shown in Table 3, 83.1% Ti, 5.50% Al, 2.50% Sn, 3.00% Zr, 1.55% Mo, 0.35% Si, 4.00% Cr are placed in different containers according to their types for use. All raw materials are decontaminated and placed in a muffle furnace at 100-200°C for 10-12 hours for drying.

[0099] (2) Furnace loading

[0100] Place the graphite crucible in the pouring position of the furnace, turn over the crucible used for smelting to calibrate the position of the graphite crucible used for pouring, and then load the raw materials mentioned in step (1) into the crucible used for smelting.

[0101] (3) Vacuum after closing the furnace door

[0102] Close the furnace door and repeatedly evacuate the furnace 3 times to make the vacuum degree in the furnace reach 1*10 -3 Pa.

[0103] (4) Melting

[0104] Start smelting, increase the power to 1kw, keep it for 3 minutes; increase the power to 2kw, keep it for 3 minutes; increase the power to 3kw, keep it for 3 minutes, and maintain the power until the raw materials are completely melted; if the raw materials cannot be completely melted at this power, increase the power to 4kw until all the raw materials are completely melted.

[0105] (5) Homogenization

[0106] After all the raw materials are melted, keep the power at 3kw for 5 minutes, then reduce the power to 2kw and keep it for 5 minutes, then increase the power to 3kw and keep it for 5 minutes, repeat the above process of reducing and increasing the power 3 times, and make the alloy composition more uniform through the effect of electromagnetic stirring.

[0107] (6) After smelting, pouring

[0108] After smelting is completed, the molten alloy is poured into a graphite crucible, the power is reduced to 0, and the furnace is cooled to room temperature.

[0109] (7) After cooling to room temperature, the vacuum is broken, the furnace door is opened, and the titanium alloy ingot in the graphite crucible is taken out to obtain a titanium alloy ingot.

[0110] The chemical composition of the high temperature titanium alloy is shown in Table 5, and the mechanical properties are shown in Table 6.

[0111] Table 5 Chemical composition of high temperature titanium alloy (wt.%)

[0112]

[0113]

[0114] Table 6 Mechanical properties of high temperature titanium alloys

[0115]

[0116] Comparative Examples 1-3

[0117] (1) Weighing

[0118] In the composition range of the designed high-temperature titanium alloy shown in Table 7, the alloying element Cr is not added, and the rest is weighed 87.15% Ti, 5.50% Al, 2.50% Sn, 3.00% Zr, 1.50% Mo, and 0.35% Si, and is placed in different containers according to the type for standby use. All raw materials are decontaminated and placed in a muffle furnace at 100-200°C for 10-12 hours for drying.

[0119] (2) Furnace loading

[0120] Place the graphite crucible in the pouring position of the furnace, turn over the crucible used for smelting to calibrate the position of the graphite crucible used for pouring, and then load the raw materials mentioned in step (1) into the crucible used for smelting.

[0121] (3) Vacuum after closing the furnace door

[0122] Close the furnace door and repeatedly evacuate the furnace 3 times to make the vacuum degree in the furnace reach 1*10 -3 Pa.

[0123] (4) Melting

[0124] Start smelting, increase the power to 1kw, keep it for 3 minutes; increase the power to 2kw, keep it for 3 minutes; increase the power to 3kw, keep it for 3 minutes, and maintain the power until the raw materials are completely melted; if the raw materials cannot be completely melted at this power, increase the power to 4kw until all the raw materials are completely melted.

[0125] (5) Homogenization

[0126] After all the raw materials are melted, keep the power at 3kw for 5 minutes, then reduce the power to 2kw and keep it for 5 minutes, then increase the power to 3kw and keep it for 5 minutes, repeat the above process of reducing and increasing the power 3 times, and make the alloy composition more uniform through the effect of electromagnetic stirring.

[0127] (6) After smelting, pouring

[0128] After smelting is completed, the molten alloy is poured into a graphite crucible, the power is reduced to 0, and the furnace is cooled to room temperature.

[0129] (7) After cooling to room temperature, the vacuum is broken, the furnace door is opened, and the titanium alloy ingot in the graphite crucible is taken out to obtain a titanium alloy ingot.

[0130] The chemical composition of the high temperature titanium alloy is shown in Table 7, and the mechanical properties are shown in Table 8.

[0131] Table 7 Chemical composition of high temperature titanium alloy (wt.%)

[0132]

[0133] Table 8 Mechanical properties of high temperature titanium alloys

[0134]

[0135] Comparative Examples 4-6

[0136] (1) Weighing

[0137] Comparative Examples 4-6 are high-temperature titanium alloy IMI829 developed in the UK, with Al: 5.5%, Sn: 4.0%, Zr: 3.0%, Mo: 0.3%, Si: 0.3%, Nb: 1.0%, impurity components <0.1%, and the balance is Ti. The service temperature of the alloy is 580°C.

[0138] The rest are weighed 85.90% Ti, 5.50% Al, 4.00% Sn, 3.00% Zr, 0.30% Mo, 0.30% Si, and 1.00% Nb, and are placed in different containers for later use. All raw materials are decontaminated and placed in a muffle furnace at 100-200°C for 10-12 hours for drying.

[0139] (2) Furnace loading

[0140] Place the graphite crucible in the pouring position of the furnace, turn over the crucible used for smelting to calibrate the position of the graphite crucible used for pouring, and then load the raw materials mentioned in step (1) into the crucible used for smelting.

[0141] (3) Vacuum after closing the furnace door

[0142] Close the furnace door and repeatedly evacuate the furnace 3 times to make the vacuum degree in the furnace reach 1*10 -3 Pa.

[0143] (4) Melting

[0144] Start smelting, increase the power to 1kw, keep it for 3 minutes; increase the power to 2kw, keep it for 3 minutes; increase the power to 3kw, keep it for 3 minutes, and maintain the power until the raw materials are completely melted; if the raw materials cannot be completely melted at this power, increase the power to 4kw until all the raw materials are completely melted.

[0145] (5) Homogenization

[0146] After all the raw materials are melted, keep the power at 3kw for 5 minutes, then reduce the power to 2kw and keep it for 5 minutes, then increase the power to 3kw and keep it for 5 minutes, repeat the above process of reducing and increasing the power 3 times, and make the alloy composition more uniform through the effect of electromagnetic stirring.

[0147] (6) After smelting, pouring

[0148] After smelting is completed, the molten alloy is poured into a graphite crucible, the power is reduced to 0, and the furnace is cooled to room temperature.

[0149] (7) After cooling to room temperature, the vacuum is broken, the furnace door is opened, and the titanium alloy ingot in the graphite crucible is taken out to obtain a titanium alloy ingot.

[0150] The chemical composition of the high temperature titanium alloy is shown in Table 9, and the mechanical properties are shown in Table 10.

[0151] Table 9 Chemical composition of IMI829 high temperature titanium alloy (wt.%)

[0152]

[0153]

[0154] Table 10 Mechanical properties of IMI829 high temperature titanium alloy

[0155]

[0156] From the above embodiments and comparative examples, it can be seen that compared with the prior art, the present invention, based on the traditional high-temperature titanium alloy basic Ti-Al-Sn-Zr-Mo-Si system, effectively adds the Cr element which helps to improve the high-temperature oxidation resistance of the high-temperature titanium alloy through a large number of experimental studies. The performance of the alloy at 650°C can reach: tensile strength>600MPa, yield strength>480MPa, and elongation>12.0%.

[0157] In combination with the smelting method of the present invention, the uniformity of the alloy is effectively improved. As can be seen from the accompanying drawings, the uniformity of the alloy of the embodiment of the present invention is significantly improved compared with the comparative example.

[0158] The basic principles and main features of the invention and the advantages of the invention are shown and described above.

[0159] Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall all fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A Cr-containing near-α high-temperature titanium alloy having a service temperature of more than 600°C, characterized in that: Calculated by weight percentage, it includes the following components: Al：4.5-6.5％； Sn: 1.5-4.5%; Zr：2.0-4.5％； Mo: 0.5-3.0%; Si: 0.2-0.5%; Cr：2.5-4.5％； Impurity content <0.1%; The remainder is Ti; The sum of the weight percentages of the above components is 100%.

2. A Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 1, characterized in that: The service temperature is 650°C and above.

3. A Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 1, characterized in that: The H in the impurity components is less than 0.006% or the N is less than 0.01%.

4. A method for smelting a Cr-containing near-α high-temperature titanium alloy with a service temperature of 600°C or above as claimed in any one of claims 1 to 3, characterized in that: The steps include: (1) Weighing According to the composition ratio of the titanium alloy, the corresponding titanium sponge, aluminum block, metal element and master alloy are weighed and placed separately, decontaminated and dried for later use; (2) Furnace loading After the graphite crucible is placed in place and calibrated, the raw materials in step (1) are loaded into the crucible for smelting; (3) Vacuuming Close the furnace door and repeatedly evacuate the furnace until the vacuum degree is not less than 1*10 -3 Pa; (4) Melting Gradually increase the power of vacuum melting to no less than 3kw and then maintain the power until the raw materials are completely melted; (5) Homogenization Adjust the melting power repeatedly within the power range of 2-3kw and stir until the alloy composition is uniform; (6) After smelting, pouring After smelting, the alloy melt is poured into a graphite crucible, the power is reduced to 0, and the titanium alloy ingot in the graphite crucible is taken out after the furnace is cooled to room temperature to obtain the titanium alloy ingot containing Cr near-α high-temperature titanium alloy with a service temperature of more than 600°C.

5. A smelting method for a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 4, characterized in that: The titanium sponge is 0A grade titanium sponge; The aluminum block is an aluminum block with a purity of not less than 99.99%; The metal element is zirconium sponge, and the zirconium sponge is industrial first-grade zirconium sponge; The master alloy is any one or more of a TiSn alloy, an AlMo alloy, an AlSi alloy or an AlCr alloy.

6. A smelting method for a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 4, characterized in that: The drying step is to place the product in a muffle furnace at 100-200° C. and keep the temperature for 10-12 hours for drying.

7. A method for smelting a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 4, characterized in that: After the graphite crucible is placed in place and calibrated, it is placed in the furnace pouring position, and the crucible used for smelting is turned over to calibrate the position of the graphite crucible used for pouring.

8. A method for smelting a Cr-containing near-α high-temperature titanium alloy with a service temperature of more than 600°C as claimed in claim 4, characterized in that: The power of the vacuum melting is gradually increased by 1 kW and maintained at intervals of 3-5 minutes; The repeatedly adjusting the smelting power within the power range of 2-3kw is to adjust the power within the power range of 2-3kw and keep the interval for 3-5 minutes.

9. A method for smelting a Cr-containing near-α high-temperature titanium alloy with a service temperature of 600°C or above as claimed in claim 1 or 4, characterized in that: The Cr-containing near-α high-temperature titanium alloy having a service temperature of 600° C. or higher has room temperature properties that meet the requirements of tensile strength>1200MPa, yield strength>900MPa, and elongation>6.0%; At a high temperature not less than 650 degrees Celsius, the performance reaches a tensile strength>600MPa, a yield strength>480MPa, and an elongation>12.0%.

10. Application of a Cr-containing near-α high-temperature titanium alloy having a service temperature of more than 600°C as claimed in any one of claims 1 to 3, characterized in that: The application is the preparation of blades for aircraft engines.

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