Preparation method of TC10 titanium alloy large-disc round wire for fastener

Abstract

The invention relates to the technical field of processing of titanium alloy wires for fasteners, in particular to a preparation method of a TC10 titanium alloy large-disc round wire for a fastener. The method comprises the following steps: firstly, obtaining a TC10 titanium alloy cast ingot with the diameter of 500-700mm, then cogging and forging the TC10 titanium alloy cast ingot at the temperature of 1100-1200 DEG C to form a bar billet with the diameter of 290-310mm, then roughly forging the TC10 titanium alloy bar billet at the temperature of 1000-1100 DEG C to form a bar billet with the diameter of 130-150mm, then precisely forging the TC10 titanium alloy bar billet at the temperature of 950-1050 DEG C to form a bar billet with the diameter of 95-105mm, then continuously rolling the TC10 titanium alloy bar billet at the temperature of 780-900 DEG C, rolling the bar billet into a large disc round wire with the diameter of 7.5-15mm, drawing, annealing, and finally obtaining the large disc round wire with the diameter of 7.5-15mm. And then peeling, polishing and coating treatment are carried out. At the moment, the cross section structure of the alloy is a fine and uniform equiaxial alpha + beta double-phase structure, has excellent strength and plasticity, and meets the requirements of TC10 titanium alloy materials for fasteners.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy wire processing for fasteners, and in particular to a method for preparing a TC10 titanium alloy large-coil round wire for fasteners. Background Art

[0002] TC10 titanium alloy is a dual-phase high-strength titanium alloy rich in β-phase stabilizing elements developed from TC4 alloy. Compared with TC4 alloy, the content of β-phase stabilizing element V is increased, and β-phase stabilizing elements Fe and Cu are added, thereby increasing the hardenability of the alloy, which can make its hardenability thickness reach 38.1~50.4mm, thus making up for the disadvantage of poor hardenability of TC4 alloy in engineering applications. In addition, the neutral element Sn is added to the alloy, so that its application temperature can be increased to 315℃.

[0003] In recent years, the use of titanium alloys and composite materials as the main materials for aviation structures has shown a clear upward trend, and they are increasingly used in main load-bearing structures. The electrical potential of titanium alloys matches well with composite materials, making titanium alloys the best connecting material for composite materials. In order to meet the needs of structural optimization and overall structural technology development, a large-diameter, high-load, and high-fatigue single-sided installation bolt and nut system has been developed. As the raw material for the core rod of an important component of single-sided connecting bolts, TC10 titanium alloy has a very broad future development and application prospect. However, at present, most of the TC10 titanium alloy wires used for domestic fasteners are processed in small batches, mainly straight strips, and the consistency of product quality is difficult to guarantee, resulting in large fluctuations in the mechanical properties of the prepared fasteners and difficulty in ensuring product quality stability.

[0004] Therefore, it is of great engineering significance to study the preparation process of large single weight round TC10 titanium alloy wire and prepare high-quality and high-uniformity large single weight round TC10 titanium alloy wire. Summary of the invention

[0005] Based on this, it is necessary to address the above technical problems. The present invention provides a method for preparing high-quality, high-uniformity TC10 titanium alloy large-coil round wire for fasteners. The prepared TC10 titanium alloy wire has fine and uniform microstructure, good consistency, high strength, good plasticity, and good surface quality and dimensional tolerance.

[0006] The technical solution of the present invention is:

[0007] A method for preparing a large-scale round wire of TC10 titanium alloy for fasteners, the specific steps are as follows:

[0008] Step 1, prepare ingot: take TC10 titanium alloy ingot with a diameter of 500-700 mm, and the composition of TC10 titanium alloy ingot is as follows by weight percentage: Al 5.00-6.50%, V 5.00-6.50%, Sn 1.50-2.50%, Fe0.35-1.00%, Cu0.35-1.00%, O≤0.20%, C≤0.05%, N≤0.04%, H≤0.015%, Y≤0.005%, other single impurity elements≤0.10%, the total impurity elements≤0.40%, and the balance is Ti;

[0009] Step 2, billet forging: heat the heating furnace to 850-950℃ to load the ingot, raise the temperature to 1100-1200℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the forging machine. After stretching, the diameter of the billet is 290-310mm, the total deformation is 70-80%, and the surface defects are repaired;

[0010] Step 3, rough forging: heat the heating furnace to 800-900℃ to load the billet, raise the temperature to 1000-1100℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the forging machine. After stretching, the diameter of the billet is 130-150mm, and the total deformation is 70-90%. The billet is rough forged and the surface defects are repaired;

[0011] Step 4, fine forging: heat the heating furnace to 700-800℃ to load the billet into the furnace, raise the temperature to 950-1050℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the fine forging machine. After stretching, the diameter of the billet is 95-105mm, and the total deformation is 40-60%. The billet after fine forging is obtained, and the surface defects are repaired;

[0012] Step 5, continuous rolling: the bar billet after fine forging is heated to 840-920°C by electromagnetic induction heating, kept at this temperature for 5-10 minutes, and then rolled in a continuous rolling mill, and the diameter of the round wire billet after rolling is 7.5-15 mm;

[0013] Step 6: Drawing: warm drawing the rolled wire blank at a temperature of 700-780°C, with a deformation of 5-20% per drawing pass;

[0014] Step 7: Annealing: anneal the drawn wire in a heat treatment furnace for 1 to 3 hours at a temperature of 700 to 780°C and in an air cooling mode;

[0015] Step 8: Peeling: Peel the annealed wire with a peeling amount of more than 0.5 mm;

[0016] Step 9, polishing: polish the peeled wire, the surface roughness Ra of the polished wire is ≤1.2μm, and the out-of-roundness is ≤0.01mm;

[0017] Step 10: Coating: The polished wire is coated with a coating having a thickness of 1 to 15 μm.

[0018] In the step 1, the process of preparing the ingot is: sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, iron powder, copper powder and titanium dioxide are mixed and pressed into electrodes, and subjected to vacuum consumable arc melting for not less than 3 times to obtain a TC10 titanium alloy cylindrical ingot with a diameter of 550 to 650 mm, and the alloy phase transition point is 945±10°C.

[0019] In the step 2, the blank forging is free forging, the holding temperature is 1125-1175° C., and the total deformation is 72-78%.

[0020] In the step 3, the rough forging is free forging, the holding temperature is 1025-1075° C., and the total deformation is 75-85%.

[0021] In the step 4, the finishing forging temperature is 975-1025° C., the total deformation is 45-55%, and the cut length is 4500-5500 mm.

[0022] In the step 5, the continuous rolling temperature is 860-900° C., and the total deformation is greater than or equal to 97%.

[0023] In the step six, the warm drawing temperature is 720-760° C., the deformation amount of each drawing pass is 5-15%, and the total deformation amount is 5%-60%.

[0024] In the step seven, the annealing temperature is 750-780° C., and the annealing time is 2-2.5 hours.

[0025] In the step eight, mold peeling is adopted, and the peeling amount is greater than 0.5 mm.

[0026] In the step 10, the coating is MoS 2 The coating made of the mixture of graphite and graphite is applied on the surface of the wire, and the coating thickness after coating is 1 to 15 μm. The obtained TC10 titanium alloy wire weighs 150 to 200 kg and has a diameter of 3 to 15 mm.

[0027] The design idea of ​​the present invention is:

[0028] The method of the present invention first obtains a TC10 titanium alloy ingot with a diameter of 500-700mm, then forges the TC10 titanium alloy ingot at 1100-1200°C into a rod blank with a diameter of 290-310mm, then rough forges the TC10 titanium alloy rod blank at 1000-1100°C into a rod blank with a diameter of 130-150mm, then fine forges the TC10 titanium alloy rod blank at 950-1050°C into a rod blank with a diameter of 95-105mm, then continuously rolls the TC10 titanium alloy rod blank at 780-900°C to form a large round wire with a diameter of 7.5-15mm, then draws, then anneals, then peels, polishes and coats. Thus, the cross-sectional structure of the alloy obtained by the overall technical solution of the present invention is a fine, uniform, equiaxed α+β dual-phase structure, the surface is in a lubricating coating state, the wire coil weight is greater than 100KG, has relatively excellent strength and plasticity, and meets the requirements of TC10 titanium alloy materials for fasteners.

[0029] The advantages and beneficial effects of the present invention are:

[0030] (1) In the composition design of the present invention, the Al element content is controlled at 5.25-5.75wt%, the V element content is controlled at 5.25-5.75wt%, the Sn element content is controlled at 1.75-2.25wt%, the Fe element content is controlled at 0.4-0.6wt%, the Cu element content is controlled at 0.4-0.6wt%, the O element content is controlled at 0.12-0.16wt%, and the phase transition point is controlled at 945±10°C, which can effectively improve the strength of the solution-aged TC10 titanium alloy while having good plasticity.

[0031] (2) The total deformation of continuous rolling in the present invention is greater than 95%, the continuous rolling temperature is controlled, and the continuous rolling large deformation mode is used. The microstructure of the TC10 titanium alloy after rolling is a fine, uniform, equiaxed dual-phase structure.

[0032] (3) The present invention can obtain a large single weight TC10 titanium alloy wire for fasteners with uniform microstructure, excellent surface quality and excellent dimensional tolerance through continuous rolling and warm drawing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a microstructure photograph of the TC10 titanium alloy rod with a diameter of φ8 mm obtained in Example 1.

[0034] Figure 2 This is a microstructure photograph of the TC10 titanium alloy rod with a diameter of φ10 mm obtained in Example 2.

[0035] Figure 3 This is a microstructure photograph of the TC10 titanium alloy rod with a diameter of φ12 mm obtained in Example 3.

[0036] Figure 4This is a microstructure photograph of the TC10 titanium alloy rod with a diameter of φ8 mm obtained in Comparative Example 1. DETAILED DESCRIPTION

[0037] In the specific implementation process, the present invention provides a method for preparing a high-quality microstructure TC10 titanium alloy large single weight round wire for fasteners, which is specifically implemented in the following steps:

[0038] Step 1, ingot preparation: Sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, iron powder, copper powder and titanium dioxide are mixed and pressed into electrodes, and subjected to vacuum consumable arc melting for not less than 3 times to obtain a TC10 titanium alloy cylindrical ingot with a diameter of 500-700 mm (preferably 550-650 mm).

[0039] The TC10 titanium alloy ingot is composed of the following elements in weight percentage: Al 5.00-6.50% (preferably 5.25-5.75%), V 5.00-6.50% (preferably 5.25-5.75%), Sn 1.50-2.50% (preferably 1.75-2.25%), Fe 0.35-1.00% (preferably 0.4-0.6%), Cu 0.35-1.00% (preferably 0.4-0.6%), O≤0.20% (preferably 0.12-0.16%), C≤0.05%, N≤0.04%, H≤0.015%, Y≤0.005%, other single impurity elements (including Mg, Ca, Mo, etc.)≤0.10%, the total impurity elements≤0.40%, and the balance is Ti (the alloy phase transition point is 945±10°C);

[0040] Step 2, blank forging: heat the box-type industrial resistance furnace to 900°C, heat it to 1100-1200°C (155°C-255°C above the phase change point, preferably 1125-1175°C), keep it warm for 2-3 hours, take it out of the furnace and stretch it on a free forging machine. After stretching, the diameter of the bar billet is 290-310mm, the total deformation is 70-80% (preferably 72-78%), and the surface defects are repaired;

[0041] Step 3, rough forging: heat the heating furnace to 800-900°C to load the billet into the furnace, raise the temperature to 1000-1100°C (55-155°C above the phase change point, preferably 1025-1075°C), keep warm for 2-3 hours, take it out of the furnace and stretch it on a free forging machine. After stretching, the diameter of the billet is 130-150mm, the total deformation is 70-90% (preferably 75-85%), and the billet is obtained after rough forging, and the surface defects are repaired;

[0042] Step 4, fine forging: heat the box-type industrial resistance furnace to 700-800°C to load the bar blank into the furnace, raise the temperature to 950-1050°C (5-105°C above the phase change point, preferably 975-1025°C), keep warm for 2-3 hours, take it out of the furnace and stretch it on the fine forging machine. After stretching, the diameter of the bar blank is 95-105mm, the total deformation is 40-60% (preferably 45-55%), cut into a length of about 4500-5500mm, and the weight is 150-210KG. The bar blank after fine forging is obtained, and the surface defects are repaired;

[0043] Step 5, continuous rolling: the bar billet after fine forging is heated to 840-920°C (25-105°C below the phase transition point, preferably 860-900°C) by electromagnetic induction heating, kept warm for 5-10 minutes, and then rolled in a continuous rolling mill. After rolling, the weight of the round wire billet is 150-205KG, the diameter is 7.5-15mm, and the total rolling deformation is greater than or equal to 97%;

[0044] Step 6, drawing: warm drawing the rolled wire blank, the warm drawing temperature is 700-780°C (165-245°C below the phase transition point, preferably 720-760°C), the deformation of each drawing pass is 5-20% (preferably 5-15%), and the total deformation is 5%-60%;

[0045] Step 7, annealing: annealing the drawn wire in a heat treatment furnace for 1 to 3 hours (preferably 2 to 2.5 hours), the annealing temperature is 700 to 780° C. (165 to 245° C. below the phase transition point, preferably 750 to 780° C.), and the cooling method is air cooling;

[0046] Step 8: Peeling: Use a mold to peel the annealed wire, and the peeling amount is greater than 0.5mm;

[0047] Step 9, polishing: polish the peeled wire, the surface roughness Ra of the polished wire is ≤1.2μm, and the out-of-roundness is ≤0.01mm;

[0048] Step 10: Coating: The polished wire is coated with a coating having a thickness of 1 to 15 μm. The obtained TC10 titanium alloy wire has a weight of 150 to 200 kg and a diameter of 3 to 15 mm.

[0049] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0050] Example 1

[0051] In this embodiment, a method for preparing a large-scale round wire of TC10 titanium alloy for fasteners comprises the following steps:

[0052] Step 1, ingot preparation, sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, reduced iron powder, reduced copper powder and titanium dioxide are mixed and pressed into 26 electrodes of 100 kg, and after three vacuum consumable arc melting, 2600 kg TC10 titanium alloy ingots are obtained, and the ingot size is about φ600mm×2000mm. The composition of the TC10 titanium alloy ingot is as follows (wt%): Al 5.50, V 5.50, Sn 2.20, Fe 0.5, Cu 0.5, O 0.15, C 0.003, N 0.002, H 0.001, and the balance is Ti (alloy phase transition point is 945℃);

[0053] Step 2: Forging the blank. Heat the box-type industrial resistance furnace to 900°C and heat it to 1150°C. Keep the temperature at 205°C above the phase change point for 3 hours. Take it out of the furnace and stretch it on a free forging machine (such as a 10MN fast hydraulic forging machine). After stretching, the diameter of the bar blank is φ300mm, the forging deformation is 75%, and the surface defects are ground until the surface is bright (without cracks and oxide scale).

[0054] Step 3, rough forging, heat the box-type industrial resistance furnace to 850℃, heat it to 1050℃, keep it warm for 2.5 hours, take it out of the furnace and stretch it on the free forging machine. After stretching, the diameter of the bar billet is 140mm, the rough forging deformation is 78%, the weight is 2600KG, and the surface defects are repaired until the surface is bright (without cracks and oxide scale);

[0055] Step 4: Finish forging: heat the box-type industrial resistance furnace to 750℃, heat it to 1000℃, keep it warm for 2.5 hours, take it out of the furnace and stretch it on the finish forging machine. The diameter of the rod billet after stretching is 100mm, the deformation of the finish forging is 50%, and the length is about 5000mm, the weight is 200KG, and the surface defects are repaired until the surface is bright (without cracks and oxide scale);

[0056] Step 5, continuous rolling, using induction heating to heat the forged bar billet to 870°C, keeping it warm for 5 minutes, and then rolling it in a continuous rolling mill. After rolling, the weight of the round wire billet is 196KG, the diameter is 10mm, and the rolling deformation is 99%;

[0057] Step 6: Drawing, drawing temperature 740℃, 205℃ below the phase transition point, three drawing passes, diameter after drawing φ8.6mm, each drawing deformation is about 10%, and the total deformation is 26%;

[0058] Step 7: annealing at 780°C for 2 hours and air cooling;

[0059] Step 8: peeling: peeling the annealed wire to obtain a wire with a diameter of φ8 mm and a peeling amount of 0.6 mm;

[0060] Step nine, polishing. After polishing, the surface roughness of the wire is Ra0.8μm and the out-of-roundness is 0.005mm;

[0061] Step 10: Coating treatment: Use MoS2 on the polished wire 2 The coating made of a mixture of MoS and graphite is coated, and the coating thickness is 6 μm. The coating composition of this embodiment is as follows by weight percentage: MoS 2 30%, graphite 40%, and the rest is resin binder.

[0062] like Figure 1 As shown in the figure, the microstructure photo of TC10 titanium alloy wire with a diameter of φ8mm shows that the microstructure is a fine and uniform equiaxed dual-phase structure.

[0063] Example 2

[0064] In this embodiment, a method for preparing a large-scale round wire of TC10 titanium alloy for fasteners comprises the following steps:

[0065] Step 1, ingot preparation, sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, reduced iron powder, reduced copper powder and titanium dioxide are mixed and pressed into 26 electrodes of 100 kg, and after three vacuum consumable arc melting, 2600 kg TC10 titanium alloy ingots are obtained, and the ingot size is about φ600mm×2000mm. The composition of the TC10 titanium alloy ingot is as follows (wt%): Al 5.50, V 5.50, Sn 2.20, Fe 0.5, Cu 0.5, O 0.15, C 0.003, N 0.002, H 0.001, and the balance is Ti (alloy phase transition point is 945℃);

[0066] Step 2: Forging the blank. Heat the box-type industrial resistance furnace to 900°C and heat it to 1150°C. Keep the temperature at 205°C above the phase change point for 3 hours. Take it out of the furnace and stretch it on a free forging machine (such as a 10MN fast hydraulic forging machine). After stretching, the diameter of the bar blank is φ300mm, the forging deformation is 75%, and the surface defects are ground until the surface is bright (without cracks and oxide scale).

[0067] Step 3, rough forging, heat the box-type industrial resistance furnace to 850℃, heat it to 1050℃, keep it warm for 2.5 hours, take it out of the furnace and stretch it on the free forging machine. After stretching, the diameter of the bar billet is 140mm, the rough forging deformation is 78%, the weight is 2600KG, and the surface defects are repaired until the surface is bright (without cracks and oxide scale);

[0068] Step 4: Finish forging: heat the box-type industrial resistance furnace to 750℃ and charge it, then heat it to 1000℃ and keep it warm for 2.5 hours. Then, take it out of the furnace and stretch it on the finish forging machine. After stretching, the diameter of the bar billet is 100mm, the deformation of the finish forging is 50%, and the length is about 5000mm, the weight is 196KG, and the surface defects are repaired until the surface is bright (without cracks and oxide scale);

[0069] Step 5, continuous rolling, using induction heating to heat the forged bar billet to 850°C, keeping it warm for 5 minutes, and then rolling it in a continuous rolling mill. After rolling, the weight of the round wire billet is 192KG, the diameter is 12mm, and the rolling deformation is 98.56%;

[0070] Step 6: Drawing, drawing temperature 740℃, 205℃ below the phase transition point, three drawing passes, diameter after drawing φ10.6mm, each drawing deformation is about 7%, total deformation is 22%;

[0071] Step 7: annealing at 780°C for 2 hours and air cooling;

[0072] Step 8: peeling: peeling the annealed wire to obtain a wire with a diameter of φ10 mm and a peeling amount of 0.6 mm;

[0073] Step nine, polishing. After polishing, the surface roughness of the wire is Ra0.8μm and the out-of-roundness is 0.005mm;

[0074] Step 10: Coating treatment: Use MoS2 on the polished wire 2 The coating made of a mixture of MoS and graphite is coated, and the coating thickness is 4 μm. The coating composition of this embodiment is as follows by weight percentage: MoS 2 30%, graphite 40%, and the rest is resin binder.

[0075] like Figure 2 As shown in the figure, the microstructure photo of TC10 titanium alloy wire with a diameter of φ10mm shows that the microstructure is a fine and uniform equiaxed dual-phase structure.

[0076] Example 3

[0077] In this embodiment, a method for preparing a large-scale round wire of TC10 titanium alloy for fasteners comprises the following steps:

[0078] Step 1, ingot preparation, sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, reduced iron powder, reduced copper powder and titanium dioxide are mixed and pressed into 26 electrodes of 100 kg, and after three vacuum consumable arc melting, 2600 kg TC10 titanium alloy ingots are obtained, and the ingot size is about φ600mm×2000mm. The composition of the TC10 titanium alloy ingot is as follows (wt%): Al 5.50, V 5.50, Sn 2.20, Fe 0.5, Cu 0.5, O 0.15, C 0.003, N 0.002, H 0.001, and the balance is Ti (alloy phase transition point is 945℃);

[0079] Step 2: Forging the blank. Heat the box-type industrial resistance furnace to 900°C and heat it to 1150°C. Keep the temperature at 205°C above the phase change point for 3 hours. Take it out of the furnace and stretch it on a free forging machine (such as a 10MN fast hydraulic forging machine). After stretching, the diameter of the bar blank is φ300mm, the forging deformation is 75%, and the surface defects are ground until the surface is bright (without cracks and oxide scale).

[0080] Step 3, rough forging, heat the box-type industrial resistance furnace to 850℃, heat it to 1050℃, keep it warm for 2.5 hours, take it out of the furnace and stretch it on the free forging machine. After stretching, the diameter of the bar billet is 140mm, the rough forging deformation is 78%, the weight is 2600KG, and the surface defects are repaired until the surface is bright (without cracks and oxide scale);

[0081] Step 4: Finish forging: heat the box-type industrial resistance furnace to 750℃, heat it to 1000℃, keep it warm for 2.5 hours, take it out of the furnace and stretch it on the finish forging machine. The diameter of the rod billet after stretching is 100mm, the deformation of the finish forging is 50%, the length is about 5000mm, the weight is 204KG, and the surface defects are ground until the surface is bright (without cracks and oxide scale);

[0082] Step 5, continuous rolling, using induction heating to heat the forged bar billet to 900°C, keeping it warm for 5 minutes, and then rolling it in a continuous rolling unit. After rolling, the weight of the round wire billet is 200KG, the diameter is 15mm, and the rolling deformation is 97.75%;

[0083] Step 6: Drawing, drawing temperature 740℃, 205℃ below the phase transition point, three drawing passes, diameter after drawing φ12.6mm, each drawing deformation is about 10%, and the total deformation is 29%;

[0084] Step 7: annealing at 780°C for 2 hours and air cooling;

[0085] Step 8: peeling: peeling the annealed wire to obtain a wire with a diameter of φ12 mm and a peeling amount of 0.6 mm;

[0086] Step nine, polishing. After polishing, the surface roughness of the wire is Ra0.8μm and the out-of-roundness is 0.005mm;

[0087] Step 10: Coating treatment: Use MoS2 on the polished wire 2 The coating was made of a mixture of MoS and graphite, and the coating thickness was 8μm. 2 30%, graphite 40%, and the rest is resin binder.

[0088] like Figure 3 As shown in the figure, the microstructure photo of TC10 titanium alloy wire with a diameter of φ12mm shows that the microstructure is a fine and uniform equiaxed dual-phase structure.

[0089] Comparative Example 1

[0090] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that the annealing temperature in step 7 of Comparative Example 1 is 860° C., and the rest of the process and conditions are the same as those of Example 1. Figure 4 As shown, the diameter of the TC10 titanium alloy obtained in Comparative Example 1 is Microstructure photo of the rod. The grain size in the microstructure of Comparative Example 1 is coarse and does not meet the microstructure requirements of TC10 titanium alloy for fasteners.

[0091] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing TC10 titanium alloy large round wire for fasteners, characterized in that: The specific steps are as follows: Step 1, prepare ingot: take TC10 titanium alloy ingot with a diameter of 500-700 mm, and the composition of TC10 titanium alloy ingot is as follows by weight percentage: Al 5.00-6.50%, V 5.00-6.50%, Sn 1.50-2.50%, Fe 0.35-1.00%, Cu0.35-1.00%, O≤0.20%, C≤0.05%, N≤0.04%, H≤0.015%, Y≤0.005%, other single impurity elements≤0.10%, the total impurity elements≤0.40%, and the balance is Ti; Step 2, billet forging: heat the heating furnace to 850-950℃ to load the ingot, raise the temperature to 1100-1200℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the forging machine. After stretching, the diameter of the billet is 290-310mm, the total deformation is 70-80%, and the surface defects are repaired; Step 3, rough forging: heat the heating furnace to 800-900℃ to load the billet, raise the temperature to 1000-1100℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the forging machine. After stretching, the diameter of the billet is 130-150mm, and the total deformation is 70-90%. The billet is rough forged and the surface defects are repaired; Step 4, fine forging: heat the heating furnace to 700-800℃ to load the billet into the furnace, raise the temperature to 950-1050℃, keep it warm for 2-3 hours, take it out of the furnace and stretch it on the fine forging machine. After stretching, the diameter of the billet is 95-105mm, and the total deformation is 40-60%. The billet after fine forging is obtained, and the surface defects are repaired; Step 5, continuous rolling: the bar billet after fine forging is heated to 840-920°C by electromagnetic induction heating, kept at this temperature for 5-10 minutes, and then rolled in a continuous rolling mill, and the diameter of the round wire billet after rolling is 7.5-15 mm; Step 6: Drawing: warm drawing the rolled wire blank at a temperature of 700-780°C, with a deformation of 5-20% per drawing pass; Step 7: Annealing: anneal the drawn wire in a heat treatment furnace for 1 to 3 hours at a temperature of 700 to 780°C and in an air cooling mode; Step 8: Peeling: Peel the annealed wire with a peeling amount of more than 0.5 mm; Step 9, polishing: polish the peeled wire, the surface roughness Ra of the polished wire is ≤1.2μm, and the out-of-roundness is ≤0.01mm; Step 10: Coating: The polished wire is coated with a coating having a thickness of 1 to 15 μm.

2. The preparation method according to claim 1, characterized in that: Preferably, in step one, the process of preparing the ingot is: sponge titanium, aluminum beans, aluminum-vanadium master alloy, titanium-tin alloy, iron powder, copper powder and titanium dioxide are mixed and pressed into electrodes, and subjected to vacuum consumable arc melting for no less than 3 times to obtain a TC10 titanium alloy cylindrical ingot with a diameter of 550 to 650 mm, and the alloy phase transition point is 945±10°C.

3. The preparation method according to claim 1, characterized in that: Preferably, in the step 2, the blank forging is free forging, the holding temperature is 1125-1175° C., and the total deformation is 72-78%.

4. The preparation method according to claim 1, characterized in that: Preferably, in step three, the rough forging is free forging, the holding temperature is 1025-1075° C., and the total deformation is 75-85%.

5. The preparation method according to claim 1, characterized in that: Preferably, in step 4, the fine forging temperature is 975-1025° C., the total deformation is 45-55%, and the cut length is 4500-5500 mm.

6. The preparation method according to claim 1, characterized in that: Preferably, in step five, the continuous rolling temperature is 860-900° C., and the total deformation is greater than or equal to 97%.

7. The preparation method according to claim 1, characterized in that: Preferably, in step six, the warm drawing temperature is 720-760° C., the deformation amount of each drawing pass is 5-15%, and the total deformation amount is 5%-60%.

8. The preparation method according to claim 1, characterized in that: Preferably, in step seven, the annealing temperature is 750-780° C., and the annealing time is 2-2.5 hours.

9. The preparation method according to claim 1, characterized in that: Preferably, in step eight, mold peeling is adopted, and the peeling amount is greater than 0.5 mm.

10. The preparation method according to claim 1, characterized in that: Preferably, in the step ten, the surface of the wire is coated with a coating made of a mixture of MoS2 and graphite, and the coating thickness after coating is 1 to 15 μm. The obtained TC10 titanium alloy wire weighs 150 to 200 kg and has a diameter of 3 to 15 mm.

Images