Preparation process of TC11 high-temperature titanium alloy large-specification bar
By optimizing the smelting, forging, and heat treatment processes of TC11 high-temperature titanium alloy bars, the problem of preparing large-size bars has been solved, enabling efficient and low-cost production of high-performance bars that meet the standards for use in aerospace equipment.
Patent Information
- Application Number
- CN202512017794.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-02-06
AI Technical Summary
Existing manufacturing processes are insufficient for producing large-size TC11 high-temperature titanium alloy bars. They suffer from defects such as large temperature gradients between the core and surface, easy shear cracking, and surface folding. Furthermore, heat treatment processes cannot achieve uniformity between the core and surface structures, resulting in excessive differences in longitudinal and transverse tensile strength, which fails to meet the isotropic requirements of high-end equipment.
By optimizing key process parameters such as smelting, forging, rolling and heat treatment, adopting multi-stage smelting process, multi-pass small deformation forging and isothermal annealing treatment, combined with induction heating device to control temperature gradient, and using centerless grinder and grinding aid for processing, the uniformity of ingot composition and excellent mechanical properties are ensured.
Stable preparation of large-diameter TC11 high-temperature titanium alloy bars with diameters of 250-300mm and lengths of 4000-6000mm has been achieved, meeting the high-performance requirements of aerospace equipment, reducing production costs, improving tensile properties, and reducing frictional resistance and surface damage during grinding.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of alloy technology, specifically to a process for preparing large-diameter bars of TC11 high-temperature titanium alloy. Background Technology
[0002] TC11 high-temperature titanium alloy, a typical α+β type titanium alloy, possesses excellent high-temperature strength, oxidation resistance, and fatigue performance, making it a core material for manufacturing critical components such as compressor blades and casings for aero-engines. With the development of aerospace equipment towards larger sizes and higher reliability, the demand for TC11 high-temperature titanium alloy bars is constantly increasing. The current market demand for large-sized bars with diameters ≥150mm and lengths ≥3000mm is insufficient to meet performance requirements. However, existing manufacturing processes have the following technical shortcomings: during large-sized ingot forging, the temperature gradient between the core and surface is large, and if deformation process parameters are not properly controlled, defects such as shear cracks and surface folds can easily occur; existing heat treatment processes cannot achieve uniform control of the microstructure between the core and surface of large-sized bars, resulting in excessive differences in longitudinal and transverse tensile strength, failing to meet the isotropic requirements of high-end equipment. Therefore, developing a process that can solve the above problems and achieve high-quality, high-efficiency manufacturing of large-sized TC11 high-temperature titanium alloy bars has become an urgent technological breakthrough in this field. Summary of the Invention
[0003] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a manufacturing process for large-size TC11 high-temperature titanium alloy bars. By optimizing key process parameters such as melting, forging, rolling, and heat treatment, the process improves the uniformity of ingot composition, suppresses forging defects, and ultimately yields large-size TC11 high-temperature titanium alloy bars with excellent mechanical properties, meeting the application needs of high-end fields such as aerospace.
[0004] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a process for preparing large-diameter TC11 high-temperature titanium alloy bars, wherein the process for preparing large-diameter TC11 high-temperature titanium alloy bars is as follows: S1. Ingredients: 85-90% pure sponge titanium (99.7% purity), 2.1-3.3% Al-Mo master alloy (Mo content 55%), 1-2.3% Zr block (99.9% purity), 1.2-1.4% Sn block (99.9% purity), 3.0-4% Al, 1.3-1.6% Mo, 1.4-1.5% Zr, 1-1.1% Cr, 0.8-1% V, balance Ti; S2. Crush the sponge titanium to remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block, and pure Sn block into small pieces with a side length of 30-40mm, ultrasonically clean them with acetone solution for 16-20 minutes, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current and voltage to 25-35V, and the melting time to 50-55min to obtain a primary ingot with a diameter of 400-500mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 12-14kA, voltage to 35-38V, current ramp rate to 0.3-0.4kA / min, cool down, and melt for 1-1.3h to obtain a secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 70-80kW, cooling bed temperature gradient controlled at 10-15℃ / cm, finally obtained a primary ingot with a diameter of 550-600mm and a length of 2000-2100mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 6-8℃ / min, raise the temperature to 930-960℃, and hold the temperature to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a deformation of 15-20% per pass and a total deformation of 60-70%. During the forging process, maintain the temperature difference between the mold and the ingot through an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 320-350mm is obtained, and then isothermal annealing is performed: temperature 750℃-800℃, holding time 150-200min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 3-5℃ / min, heated to 900-920℃, and held for 100-120min. Multiple passes are then performed using a Φ800mm-Φ1000mm two-roll reversible hot rolling mill. The first pass has a reduction of 20-25%, with subsequent passes gradually decreasing to 10-15%. Online reheating is performed after each pass at a temperature of 850℃-880℃, with a holding time of 15-25min to prevent excessively low billet temperature from increasing deformation resistance. Finally, a rough bar with a diameter of 250-300mm and a length of 4000-6000mm is obtained. Water mist cooling is used during rolling at a rate of 5-8℃ / s. Cooling is stopped when the surface temperature of the bar reaches 300-400℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2 Pa, heating rate 3-5℃ / min, heating to 920-940℃, holding for 30-40min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 600-620℃, held for 240-300min, then furnace cooled to room temperature, added corrosion inhibitor and soaked for 10-20min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added, finally obtaining TC11 high temperature titanium alloy large-size bar.
[0005] Furthermore, in step S2, the sponge titanium is crushed to a particle size of 10-20 mm.
[0006] Furthermore, in S3, the smelting current is controlled to be 10-12kA.
[0007] Furthermore, in S4, the cooling rate is 0.5-0.8℃ / min.
[0008] Furthermore, in S6, the heat preservation time is 60-80 minutes.
[0009] Furthermore, in S7, the temperature difference is 20-30℃.
[0010] Furthermore, in S10, the corrosion inhibitor is oleic acid imidazoline.
[0011] Furthermore, in S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.
[0012] (iii) Beneficial technical effects This invention can stably prepare large-size TC11 high-temperature titanium alloy bars with a diameter of 250-300mm and a length of 4000-6000mm. The product performance fully meets the usage standards of key components such as compressor blades and casings of aero-engines, effectively solving the current market demand for large-size, high-performance TC11 titanium alloy bars and providing key materials for the development of aerospace equipment.
[0013] The heat-treated bars were processed using a centerless grinder with 1% grinding aid (100mL water, 0.2g triethanolamine, and 0.3g sodium benzoate). The grinding aid can reduce frictional resistance and surface damage during the grinding process. By soaking in oleic acid imidazoline, a dense protective film can be formed on the surface of the bars, which can effectively inhibit oxidation and corrosion of the titanium alloy surface.
[0014] This invention employs a multi-stage melting process with strict parameter control at each stage, effectively eliminating defects such as component segregation, porosity, and inclusions within the ingot. The isothermal forging process utilizes a "multi-pass small deformation and die heat preservation" technique, combined with post-forging isothermal annealing, to reduce forging cracking rate, lower production costs, and simultaneously improve tensile properties. The preparation process for large-diameter TC11 high-temperature titanium alloy bars based on this invention is simple, reduces production costs, and has promising application prospects. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0016] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific embodiments.
[0017] Example 1 The manufacturing process of a large-diameter TC11 high-temperature titanium alloy bar is as follows: S1. Ingredients: 85% by mass of sponge titanium with a purity of 99.7%, 2.1% by mass of Al-Mo master alloy (Mo content 55%), 1% by mass of Zr block with a purity of 99.9%, 1.2% by mass of Sn block with a purity of 99.9%, 3.0% by mass of Al, 1.3% by mass of Mo, 1.4% by mass of Zr, 1% by mass of Cr, 0.8% by mass of V, with the balance being Ti; S2. Crush the sponge titanium to a particle size of 10mm and remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block and pure Sn block into small pieces with a side length of 30mm, ultrasonically clean them with acetone solution for 16min, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current to 10kA, voltage to 25V, and melting time to 50min to obtain a one-time casting ingot with a diameter of 400mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 12kA, voltage to 35V, current ramp rate to 0.3kA / min, cooling rate to 0.5℃ / min, melting time to 1h, to obtain secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 70kW, cooling bed temperature gradient controlled at 10℃ / cm, finally obtained a primary ingot with a diameter of 550mm and a length of 2000mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 6℃ / min, heat it to 930℃, and hold it for 60min to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a pass deformation of 15% and a total deformation of 60%. During the forging process, the temperature difference between the mold and the ingot is maintained at 20°C by an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 320mm is obtained, and then isothermal annealing is performed: temperature 750℃, holding time 150min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 3℃ / min, heated to 900℃, and held for 100min. It is then rolled in multiple passes using an 800mm two-roll reversible hot rolling mill. The first pass has a reduction of 20%, and the reduction in subsequent passes is gradually reduced to 10%. After each pass, online reheating is performed at a temperature of 850℃ and a holding time of 15min to prevent the forging billet temperature from being too low, which would increase the deformation resistance. Finally, a rough bar with a diameter of 250mm and a length of 40000mm is obtained. Water mist cooling is used during the rolling process at a cooling rate of 5℃ / s. Cooling is stopped when the surface temperature of the bar reaches 300℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2Pa, heating rate 3℃ / min, heating to 920℃, holding for 30min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 600℃, held for 240min, then furnace cooled to room temperature, 2% oleic acid imidazoline is added for soaking for 10min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added to it, finally obtaining TC11 high temperature titanium alloy large-size bar; In S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.
[0018] Example 2 The manufacturing process of a large-diameter TC11 high-temperature titanium alloy bar is as follows: S1. Ingredients: 90% by mass of sponge titanium with a purity of 99.7%, 3.3% by mass of Al-Mo master alloy (Mo content 55%), 2.3% by mass of Zr block with a purity of 99.9%, 1.4% by mass of Sn block with a purity of 99.9%, 4% by mass of Al, 1.6% by mass of Mo, 1.5% by mass of Zr, 1.1% by mass of Cr, 1% by mass of V, with the balance being Ti; S2. Crush the sponge titanium to a particle size of 20mm and remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block and pure Sn block into small pieces with a side length of 40mm, ultrasonically clean them with acetone solution for 20min, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current to 12kA, voltage to 35V, and melting time to 55min to obtain a one-time casting ingot with a diameter of 500mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 14kA, voltage to 38V, current ramp rate to 0.4kA / min, cooling rate to 0.8℃ / min, melting time to 1.3h, to obtain secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 80kW, cooling bed temperature gradient controlled at 15℃ / cm, finally obtained a primary ingot with a diameter of 600mm and a length of 2100mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 8℃ / min, heat it to 960℃, and hold it for 80min to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a pass deformation of 20% and a total deformation of 70%. During the forging process, the temperature difference between the mold and the ingot is maintained at 30°C by an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 350mm is obtained, and then isothermal annealing is performed: temperature 800℃, holding time 200min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 5℃ / min, heated to 920℃, and held for 120min. It is then rolled in multiple passes using a Φ1000mm two-roll reversible hot rolling mill. The first pass has a reduction of 25%, and the reduction in subsequent passes is gradually reduced to 15%. After each pass, online reheating is performed at a temperature of 880℃ and a holding time of 25min to prevent the forging billet temperature from being too low, which would increase the deformation resistance. Finally, a rough bar with a diameter of 300mm and a length of 6000mm is obtained. Water mist cooling is used during the rolling process at a cooling rate of 8℃ / s. Cooling is stopped when the surface temperature of the bar reaches 400℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2 Pa, heating rate 5℃ / min, heating to 940℃, holding for 40min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 620℃, held for 300min, then furnace cooled to room temperature, 2% oleic acid imidazoline is added for soaking for 20min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added to it, finally obtaining TC11 high temperature titanium alloy large-size bar; In S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.
[0019] Example 3 The manufacturing process of a large-diameter TC11 high-temperature titanium alloy bar is as follows: S1. Ingredients: 87% by mass of sponge titanium with a purity of 99.7%, 2.6% by mass of Al-Mo master alloy (Mo content 55%), 1.3% by mass of Zr block with a purity of 99.9%, 1.3% by mass of Sn block with a purity of 99.9%, 3.5% by mass of Al, 1.5% by mass of Mo, 1.4% by mass of Zr, 1% by mass of Cr, 0.9% by mass of V, with the balance being Ti; S2. Crush the sponge titanium to a particle size of 15mm and remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block and pure Sn block into small pieces with a side length of 35mm, ultrasonically clean them with acetone solution for 18min, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current to 11kA, voltage to 30V, and melting time to 53min to obtain a primary ingot with a diameter of 450mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 13kA, voltage to 37V, current ramp rate to 0.35kA / min, cooling rate to 0.7℃ / min, melting time to 1.2h, to obtain secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 75kW, cooling bed temperature gradient controlled at 13℃ / cm, finally obtained a primary ingot with a diameter of 570mm and a length of 2060mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 7℃ / min, heat it to 950℃, and hold it for 70min to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a pass deformation of 17% and a total deformation of 65%. During the forging process, the temperature difference between the mold and the ingot is maintained at 26°C by an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 340mm is obtained, and then isothermal annealing is performed: temperature 770℃, holding time 180min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 4℃ / min, heated to 910℃, and held for 110min. It is then rolled in multiple passes using a 900mm two-roll reversible hot rolling mill. The first pass has a reduction of 23%, and the reduction in subsequent passes is gradually reduced to 13%. After each pass, online reheating is performed at a temperature of 870℃ and a holding time of 20min to prevent the forging billet temperature from being too low, which would increase the deformation resistance. Finally, a rough bar with a diameter of 280mm and a length of 5000mm is obtained. Water mist cooling is used during the rolling process at a cooling rate of 6℃ / s. Cooling is stopped when the surface temperature of the bar reaches 350℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2Pa, heating rate 4℃ / min, heating to 920-940℃, holding for 30-40min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 600-620℃, held for 240-300min, then furnace cooled to room temperature, 2% oleic acid imidazoline is added for soaking for 10-20min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added, finally obtaining TC11 high temperature titanium alloy large-size bar; In S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.
[0020] Example 4 The manufacturing process of a large-diameter TC11 high-temperature titanium alloy bar is as follows: S1. Ingredients: 85% by mass of sponge titanium with a purity of 99.7%, 2.1% by mass of Al-Mo master alloy (Mo content 55%), 1% by mass of Zr block with a purity of 99.9%, 1.2% by mass of Sn block with a purity of 99.9%, 3.0% by mass of Al, 1.3% by mass of Mo, 1.4% by mass of Zr, 1% by mass of Cr, 0.8% by mass of V, with the balance being Ti; S2. Crush the sponge titanium to a particle size of 10mm and remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block and pure Sn block into small pieces with a side length of 30mm, ultrasonically clean them with acetone solution for 16min, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current to 12kA, voltage to 35V, and melting time to 55min to obtain a one-time casting ingot with a diameter of 500mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 14kA, voltage to 38V, current ramp rate to 0.4kA / min, cooling rate to 0.8℃ / min, melting time to 1.3h, to obtain secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 80kW, cooling bed temperature gradient controlled at 15℃ / cm, finally obtained a primary ingot with a diameter of 600mm and a length of 2100mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 7℃ / min, heat it to 950℃, and hold it for 70min to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a pass deformation of 17% and a total deformation of 65%. During the forging process, the temperature difference between the mold and the ingot is maintained at 26°C by an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 340mm is obtained, and then isothermal annealing is performed: temperature 770℃, holding time 180min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 4℃ / min, heated to 910℃, and held for 110min. It is then rolled in multiple passes using a 900mm two-roll reversible hot rolling mill. The first pass has a reduction of 23%, and the reduction in subsequent passes is gradually reduced to 13%. After each pass, online reheating is performed at a temperature of 870℃ and a holding time of 20min to prevent the forging billet temperature from being too low, which would increase the deformation resistance. Finally, a rough bar with a diameter of 280mm and a length of 5000mm is obtained. Water mist cooling is used during the rolling process at a cooling rate of 6℃ / s. Cooling is stopped when the surface temperature of the bar reaches 350℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2 Pa, heating rate 4℃ / min, heating to 920-940℃, holding for 30-40min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 600-620℃, held for 240-300min, then furnace cooled to room temperature, 2% oleic acid imidazoline is added for soaking for 10-20min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added, finally obtaining TC11 high temperature titanium alloy large-size bar; In S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.
[0021] Table 1: Tensile properties of bars at 600℃
[0022] As shown in Table 1, the TC11 high-temperature titanium alloy large-size bars of the present invention have good mechanical properties.
[0023] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0024] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
[0025] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.
Claims
1. A process for preparing large-diameter TC11 high-temperature titanium alloy bars, characterized in that, The manufacturing process of the large-diameter TC11 high-temperature titanium alloy bars is as follows: S1. Ingredients: 85-90% pure sponge titanium (99.7% purity), 2.1-3.3% Al-Mo master alloy (Mo content 55%), 1-2.3% Zr block (99.9% purity), 1.2-1.4% Sn block (99.9% purity), 3.0-4% Al, 1.3-1.6% Mo, 1.4-1.5% Zr, 1-1.1% Cr, 0.8-1% V, balance Ti; S2. Crush the sponge titanium to remove the surface oxide scale and impurities; cut the Al-Mo master alloy, pure Zr block, and pure Sn block into small pieces with a side length of 30-40mm, ultrasonically clean them with acetone solution for 16-20 minutes, and dry them for later use. S3. Add the sponge titanium to the copper crucible as the bottom layer, then add other raw materials, and then evacuate to a vacuum level ≤ 5 × 10⁻⁶. -3 Pa, energize and start the arc, control the melting current and voltage to 25-35V, and the melting time to 50-55min to obtain a primary ingot with a diameter of 400-500mm; S4. After flipping the ingot, reload it into the copper crucible and evacuate the vacuum until the vacuum degree is ≤3×10⁻⁶. -3 Pa, adjust the melting current to 12-14kA, voltage to 35-38V, current ramp rate to 0.3-0.4kA / min, cool down, and melt for 1-1.3h to obtain a secondary ingot; S5. The secondary ingot is fed into an electron beam cooling furnace, and the vacuum degree is controlled at ≤1×10⁻⁶. -4 Pa, electron beam power 70-80kW, cooling bed temperature gradient controlled at 10-15℃ / cm, finally obtained a primary ingot with a diameter of 550-600mm and a length of 2000-2100mm; S6. Preheat the primary ingot in a bogie-type heating furnace at a heating rate of 6-8℃ / min, raise the temperature to 930-960℃, and hold the temperature to ensure uniform temperature in the core of the ingot. S7. Transfer the preheated ingot to an isothermal forging press and adopt the "multi-pass small deformation" forging method, with a pass deformation of 15-20% and a total deformation of 60-70%. During the forging process, the temperature difference between the mold and the ingot is maintained by an induction heating device to avoid cracking caused by excessive temperature gradient. S8. After forging, a forging billet with a diameter of 320-350mm is obtained, and then isothermal annealing is performed: temperature 750℃-800℃, holding time 150-200min, and furnace cooling to room temperature to eliminate forging internal stress. S9. The forging billet is fed into a walking beam furnace at a heating rate of 3-5℃ / min, heated to 900-920℃, and held for 100-120min. Multiple passes are then performed using a Φ800mm-Φ1000mm two-roll reversible hot rolling mill. The first pass has a reduction of 20-25%, with subsequent passes gradually decreasing to 10-15%. Online reheating is performed after each pass at a temperature of 850℃-880℃, with a holding time of 15-25min to prevent excessively low billet temperature from increasing deformation resistance. Finally, a rough bar with a diameter of 250-300mm and a length of 4000-6000mm is obtained. Water mist cooling is used during rolling at a rate of 5-8℃ / s. Cooling is stopped when the surface temperature of the bar reaches 300-400℃ to obtain the rough bar. S10. Feed the crude bar stock into a vacuum heat treatment furnace and evacuate it to a vacuum degree ≤5×10⁻⁶. -2 Pa, heating rate 3-5℃ / min, heating to 920-940℃, holding for 30-40min, then oil cooling to room temperature; then the bar is put back into the heat treatment furnace, heated to 600-620℃, held for 240-300min, then furnace cooled to room temperature, added corrosion inhibitor and soaked for 10-20min, then the heat-treated bar is ground using a centerless grinder, and 1% grinding aid is added, finally obtaining TC11 high temperature titanium alloy large-size bar.
2. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In step S2, the sponge titanium is crushed to a particle size of 10-20 mm.
3. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In step S3, the smelting current is controlled to be 10-12 kA.
4. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In S4, the cooling rate is 0.5-0.8℃ / min.
5. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In S6, the heat preservation time is 60-80 minutes.
6. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In S7, the temperature difference is 20-30℃.
7. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In S10, the corrosion inhibitor is imidazoline oleate.
8. The preparation process of large-size TC11 high-temperature titanium alloy bars according to claim 1, characterized in that, In S10, the grinding aid is a mixture of 100 mL water, 0.2 g triethanolamine, and 0.3 g sodium benzoate.