A method for preparing high-strength TA15 titanium alloy wire at low cost

Abstract

The application relates to the technical field of wire preparation, and particularly discloses a method for preparing high-strength TA15 titanium alloy wire at low cost, which comprises the following steps: S100, preparing TA15 titanium alloy disc round; S200, performing a discing, peeling and polishing process on the TA15 titanium alloy disc round to obtain disc wire with a bright surface; S300, performing multi-pass roll die drawing on the disc wire to obtain drawn wire; S400, performing one-time online heat treatment on the drawn wire to obtain fully annealed wire; and S500, repeatedly performing steps S300 and S400 to obtain finished wire. The method can greatly increase the drawing deformation, drawing speed and die service life of the TA15 titanium alloy wire, reduce material loss, improve the stability and consistency of the wire product, finally reduce the material processing cost and ensure the quality of the wire product.

Description

Technical Field

[0001] This invention relates to the field of wire preparation technology, and specifically to a low-cost method for preparing high-strength TA15 titanium alloy wire. Background Technology

[0002] TA15 titanium alloy, with a nominal composition of Ti-6Al-2Zr-1Mo-1V, is a high-aluminum equivalent near-α-type titanium alloy. This alloy combines the advantages of both α-type and α+β-type titanium alloys, possessing good plasticity while exhibiting excellent weldability and thermal stability. At high temperatures, it demonstrates superior creep strength and endurance strength, and can operate stably for extended periods at temperatures up to 500°C. Therefore, TA15 titanium alloy can be processed into various forms such as plates, bars, wires, and forgings, making it an important structural material in many fields. It is particularly widely used in aircraft structural components and engine manufacturing.

[0003] However, while TA15 titanium alloy possesses many advantages, it also faces some challenges. Due to its high tensile strength and deformation resistance, the preparation of TA15 titanium alloy wire involves issues such as small deformation per drawing, slow drawing speed, short die life, large peeling losses after repeated hot working, and unstable process flow. These problems result in high processing costs for TA15 titanium alloy wire, limiting its wider application.

[0004] Based on the above, it is necessary to develop a low-cost method for preparing high-strength TA15 titanium alloy wire. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the main objective of this invention is to provide a low-cost method for preparing high-strength TA15 titanium alloy wire. This method can significantly improve the drawing deformation, drawing speed, and die life of TA15 titanium alloy wire, while reducing material loss, improving the stability and consistency of wire products, ultimately reducing material processing costs and ensuring the quality of wire products.

[0006] To solve at least one of the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] According to the present invention, a method for preparing high-strength TA15 titanium alloy wire at low cost is provided, comprising the following steps: S100, preparing TA15 titanium alloy coils, wherein the metallographic structure of the TA15 titanium alloy coils contains α equiaxed crystals with an average grain size of 10~20μm; S200, performing a rounding-peeling-polishing process on the above-mentioned TA15 titanium alloy coils to obtain a bright surface coil wire; S300, performing a multi-pass roll drawing process on the coil wire to obtain a drawn wire; S400, performing a single online heat treatment on the drawn wire to obtain a fully annealed wire; S500, repeating steps S300 and S400 to obtain the finished wire.

[0008] According to one embodiment of the present invention, in step S100, a TA15 ingot is obtained by three vacuum self-consumption melting processes, and a titanium alloy disc with a diameter of Φ8.5mm is obtained by forging and rolling.

[0009] According to one embodiment of the present invention, in step S100, the TA15 titanium alloy disc is composed of the following chemical composition by weight percentage: Al: 6.0wt%~7.0wt%, Zr: 1.5wt%~2.5wt%, Mo: 0.5wt%~1.5wt%, V: 0.5wt%~1.5wt%, Fe≤0.03wt%, C≤0.02wt%, H≤0.005wt%, O≤0.05wt%, N≤0.03wt%, Si≤0.01wt%, with the balance being Ti and unavoidable impurities.

[0010] According to one embodiment of the present invention, step S200 includes: S210, performing room temperature rotary forging on the titanium alloy wire rod, wherein the rotary forging speed is controlled at 5~10 m / min, the rotary forging deformation is 10%~12%, the lubricant is industrial lubricating oil, and the dimension after rotary forging is Φ8.0mm±0.05mm; S220, peeling the wire rod after rotary forging by turning, wherein the turning tool speed is controlled at 1000~1200 r / min, and the peeling speed is... The speed is 5~7m / min, the linear speed is 28~30m / min, the peeling amount is 0.4~0.6mm, and the size after peeling is Φ7.5mm±0.05mm; S230, the peeled wire rod is polished by a belt polisher to obtain a bright wire rod. The belt mesh is selected as 240 mesh, 320 mesh, and 480 mesh, the polishing speed is 5~7m / min, the polishing frequency is 20~25Hz, and the polishing amount is 0.01~0.02mm.

[0011] According to an embodiment of the present invention, in step S300, the drawing equipment is a six-pass cold drawing machine, and six sets of dies are installed simultaneously for drawing; the roller die has a two-roll symmetrical structure, consisting of eight sets of rollers; wherein, the eight sets of rollers are arranged in a horizontal + vertical + horizontal + vertical + horizontal + vertical + horizontal + vertical manner; wherein, the first six sets of rollers are deformation rollers, and the last two sets of rollers are shaping rollers.

[0012] According to one embodiment of the present invention, the roller mold is made of cemented carbide, and its main components are Mn: 2.2 wt%~3.0 wt%, W: 8.0 wt%~9.0 wt%, Co≤0.2 wt%, Cr≤0.2 wt%, Cu≤0.5 wt%, S≤0.5 wt%, with the balance being Fe and unavoidable impurities.

[0013] According to one embodiment of the present invention, in step S300, an oily lubricant is used for lubrication; wherein, by volume percentage, the oily lubricant comprises: 50%~70% thioene, 1%~10% sorbitan monooleate, 1%~5% carboxylic acid ether, 0.1%~1% bactericide, and the remainder being base oil; wherein, the oily lubricant is diluted with deionized water at a volume ratio of 1:8~1:10, and the diluted solution is used as a drawing lubricant.

[0014] According to an embodiment of the present invention, in step S300, the accuracy of the wire exit in each pass is controlled to be within ±0.02mm, the drawing speed is 120~180m / min, the deformation amount per drawing pass is 15%, and after each cumulative reduction of diameter of the bright coiled wire is 5~6 times, annealing heat treatment is performed, and the cumulative deformation amount is controlled to be 50%~60%, thereby obtaining the drawn wire material.

[0015] According to an embodiment of the present invention, in step S400, the lubricant on the surface of the drawn wire is cleaned by online ultrasonic cleaning before heat treatment, and the ultrasonic frequency is controlled at 80~100kHz and the traveling speed is 5~10m / min.

[0016] According to one embodiment of the present invention, in step S400, the online heat treatment uses 99.999% high-purity argon as the protective gas, and controls the argon flow rate to be 15~20L / min; the heat treatment temperature is controlled to be 850℃, the holding time is 5~10min, the wire travel speed is 5~10m / min, and the cooling method is argon gas blowing cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0017] By adopting the above technical solution, the present invention has at least one of the following advantages compared with the prior art:

[0018] (1) This invention starts with the design of the roller die composition and controls the content of Mn, P and W elements to regulate the performance of the roller die, so that it can maintain high wear resistance on the basis of high strength. This can not only improve the service life of the roller die, but also provide strong support for the subsequent large deformation diameter reduction of titanium wire.

[0019] (2) This invention uses an eight-set two-roll symmetrical structure die for cold drawing, which, compared to the conventional two-set three-roll symmetrical structure die, has a higher single-pass deformation amount, deformation uniformity, and deformation smoothness. The large deformation amount of this die can fully break down the internal structure of the filament, improve its properties, and increase the product qualification rate. At the same time, this die can draw multiple passes simultaneously, which not only reduces threading time, but also increases the total deformation amount, reduces the number of heat treatments, and improves production efficiency. The drawing cost of TA15 filament is reduced to 50% of the original cost.

[0020] (3) The present invention uses an oil-based lubricant and is designed according to the formula for heavy-duty processing. It is compatible with cemented carbide molds and can lubricate the roller molds under high-speed and large deformation drawing conditions, thus extending the mold life and providing strong support for the large deformation drawing of TA15 wire.

[0021] (4) Compared with offline vacuum heat treatment equipment, the online heat treatment equipment used in this invention can ensure that the drawn wire with a large amount of distortion energy is generated during recrystallization, thereby achieving the purpose of refining the grains. In addition, solution treatment can effectively reduce the heating temperature, prevent abnormal grain growth, and help control the uniformity and consistency of the wire structure. At the same time, online heat treatment can improve the automation of the entire wire drawing process, significantly reduce manual labor and preparation time, and help reduce the processing cost of TA15 wire.

[0022] (5) The entire process of the present invention is cold processing. Compared with the traditional hot drawing process, there is no need to peel the skin before the finished product, which can save 10%~15% of the material loss rate and further reduce the processing cost of TA15 wire. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram illustrating the steps of a low-cost method for preparing high-strength TA15 titanium alloy wire according to an embodiment of the present invention;

[0025] Figure 2 Microstructure of TA15 titanium alloy wire rod with a diameter of 8.5mm according to an embodiment of the present invention;

[0026] Figure 3 Microstructure of TA15 titanium alloy wire with a diameter of 3.0 mm according to Example 1 of the present invention;

[0027] Figure 4 Microstructure diagram of TA15 titanium alloy wire with a diameter of Φ2.0mm according to Example 2 of the present invention;

[0028] Figure 5 Microstructure of TA15 titanium alloy wire with a diameter of 3.0 mm according to Comparative Example 1 of the present invention;

[0029] Figure 6 The image shows the microstructure of a 3.0mm TA15 titanium alloy wire according to Comparative Example 2 of this invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0031] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0032] This invention provides a low-cost method for preparing high-strength TA15 titanium alloy wire. For example... Figure 1 As shown, the method generally includes the following steps:

[0033] S100, prepare TA15 titanium alloy disks, wherein the metallographic structure of the TA15 titanium alloy disks contains α equiaxed crystals and the average grain size is 10~20μm;

[0034] S200, the above-mentioned TA15 titanium alloy coil is processed by rounding, peeling and polishing to obtain a bright surface coil wire.

[0035] S300 is used to perform multi-pass roller drawing of coiled wire to obtain drawn wire.

[0036] S400 is used to perform an online heat treatment on drawn wire to obtain fully annealed wire.

[0037] S500, repeat steps S300 and S400 to obtain the finished wire material.

[0038] Step S100 involves three vacuum arc remelting processes to obtain a TA15 ingot, which is then forged and rolled to obtain titanium alloy discs of appropriate diameter. In embodiments of the present invention, the TA15 titanium alloy discs may be composed of the following chemical composition by weight percentage: Al: 6.0wt%~7.0wt%, Zr: 1.5wt%~2.5wt%, Mo: 0.5wt%~1.5wt%, V: 0.5wt%~1.5wt%, Fe≤0.03wt%, C≤0.02wt%, H≤0.005wt%, O≤0.05wt%, N≤0.03wt%, Si≤0.01wt%, with the balance being Ti and unavoidable impurities. In other embodiments, those skilled in the art can utilize the teachings disclosed herein to seek the desired properties by appropriately altering the values ​​of each element. It should be understood that the use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range. The microstructure of the prepared TA15 titanium alloy disk contains α-equiaxed grains, with an average grain size preferably of 10~20 μm. The specific microstructure is shown in the attached figure. Figure 2 As shown.

[0039] In step S200, before performing the cold drawing process, the titanium disc prepared in step S100 can be subjected to rotary forging, peeling, and polishing to obtain a bright-surfaced wire. Taking a titanium alloy disc with a diameter of Φ8.5mm as an example, the drawing process may specifically include:

[0040] S210 uses a rotary forging method to perform room temperature rotary forging of titanium alloy wire rods. The rotary forging speed is controlled at 5~10m / min, the rotary forging deformation is 10%~12%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0mm±0.05mm.

[0041] S220 uses turning to peel off the outer layer of the forged wire rod. The cutting tool speed is controlled at 1000~1200 r / min, the peeling speed is 5~7 m / min, the linear speed is 28~30 m / min, the peeling amount is 0.4~0.6 mm, and the size after peeling is Φ7.5 mm±0.05 mm.

[0042] S230 uses a belt polisher to polish the stripped wire rod to obtain a shiny wire rod. The belt mesh size is selected as 240 mesh, 320 mesh, or 480 mesh, the polishing speed is 5~7m / min, the polishing frequency is 20~25Hz, and the polishing amount is 0.01~0.02mm.

[0043] In step S300, the drawing equipment is a six-pass cold drawing machine, with six sets of dies installed simultaneously for drawing. The roller die has a two-roll symmetrical structure, consisting of eight sets of rollers. The eight sets of rollers are arranged in a horizontal + vertical + horizontal + vertical + horizontal + vertical + horizontal + vertical configuration: the first six sets are forming rollers, and the last two sets are shaping rollers. The roller die material is preferably hard alloy, which possesses excellent wear resistance, pressure resistance, and high temperature resistance, effectively improving production efficiency and product quality. In the embodiments of this invention, the main components are Mn: 2.2wt%~3.0wt%, W: 8.0wt%~9.0wt%, Co≤0.2wt%, Cr≤0.2wt%, Cu≤0.5wt%, S≤0.5wt%, with the balance being Fe and unavoidable impurities.

[0044] Further, in step S300, an oil-based lubricant is used for lubrication. In embodiments of the present invention, the oil-based lubricant may contain, by volume percentage: 50%~70% thioolefins, 1%~10% sorbitan monooleate, 1%~5% carboxylic acid ethers, 0.1%~1% bactericide, and the remainder being base oil. The above-mentioned oil-based lubricant may be diluted with deionized water at a volume ratio of 1:8~1:10, and the diluted solution is used as a drawing lubricant.

[0045] Furthermore, in the drawing process of step S300, it is preferable to control the accuracy of the wire exit in each pass to within ±0.02mm, the drawing speed to be 120~180m / min, the deformation amount per drawing pass to be 15%, and after each cumulative reduction of diameter of the bright wire coil 5~6 times, annealing heat treatment is performed, and the cumulative deformation amount is controlled to be 50%~60%, to obtain the drawn wire material.

[0046] In step S400, before heat treatment, the lubricant on the surface of the drawn wire can be cleaned by online ultrasonic cleaning. Preferably, the ultrasonic frequency is controlled at 80~100kHz, and the travel speed is 5~10m / min. After ultrasonic cleaning, the wire undergoes continuous online heat treatment for complete annealing. Specifically, 99.999% high-purity argon is used as the protective gas, with an argon flow rate controlled at 15~20L / min; the heat treatment temperature is controlled at 850℃, the holding time at 5~10min, the wire travel speed at 5~10m / min, and argon gas blowing is used for cooling at a rate of 150℃ / s~180℃ / s.

[0047] In step S500, steps S300 and S400 are repeated according to the finished product size, and finally the Φ8.5mm coil is drawn into finished wire with a specification of Φ3.0-Φ1.6mm.

[0048] Through the above technical solutions, this invention starts with the wire deformation process, optimizes the structure of the roller die, adopts a new type of lubricant, and combines large deformation with heat treatment process to solve the problems of small drawing deformation, low drawing speed and low processing efficiency of high-strength TA15 titanium alloy wire, and finally achieves the goal of high-speed, large deformation and low cost preparation of high-strength titanium alloy wire.

[0049] The following are specific embodiments and process parameters of the high-strength TA15 titanium alloy wire and its preparation method according to the present invention.

[0050] Example 1

[0051] In this embodiment, 3.0 mm TA15 titanium alloy wire is prepared using 8.5 mm TA15 titanium alloy coils.

[0052] Step 100: Prepare TA15 disks with a microstructure dominated by α-equiaxed structure and an average α grain size of 10~20μm. The TA15 titanium alloy disks are composed of the following weight percentages: Al: 6.5wt%, Zr: 1.8wt%, Mo: 1.1wt%, V: 1.3wt%, Fe≤0.03wt%, C≤0.02wt%, H: 0.0035wt%, O: 0.043wt%, N: 0.02wt%, Si: 0.008wt%, with the balance being Ti and unavoidable impurities.

[0053] Step 200: The coil from Step 100 is subjected to a forging-skinning-polishing process. Specifically,

[0054] Step 210: The titanium alloy disc is forged at room temperature using a rotary forging method. The rotary forging speed is 5 m / min, the rotary forging deformation is 10%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm ± 0.05 mm.

[0055] Step 220: The forged coil is peeled off by turning. The turning tool speed is 1000 r / min, the peeling speed is 5 m / min, the linear speed is 28 m / min, the peeling amount is 0.4 mm, and the size after peeling is Φ7.6 mm ± 0.05 mm.

[0056] Step 230: Polish the peeled disc using a belt polisher. The belt mesh size is 240 or 320, the polishing speed is 5 m / min, the polishing frequency is 20 Hz, and the polishing amount is 0.01 mm.

[0057] Step 300: Apply drawing lubricant evenly to the bright filament obtained in step 200, and then perform roller drawing.

[0058] The oil-based lubricant consists of 70% thioolefins, 5% sorbitan monooleate, 1% carboxylic acid ether, 1% bactericide, and the remainder is base oil. The oil-based lubricant is diluted with deionized water at a ratio of 1:10 and used as a drawing lubricant.

[0059] The roller mold is made of cemented carbide, with the main components being Mn: 2.5wt%, W: 8.5wt%, Co: 0.78wt%, Cr: 0.01wt%, Cu: 0.18wt%, S≤0.32wt%, and the balance being Fe and unavoidable impurities.

[0060] Among them, a six-pass continuous roller drawing machine is used to draw Φ7.6mm bright wire to Φ4.2mm in 6 passes, with a drawing speed of 150m / min.

[0061] Step 400: Perform continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0062] The drawn wires are first subjected to online ultrasonic cleaning and then online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1m / min, and the cleaning medium is a weakly alkaline cleaning agent.

[0063] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min. The heating temperature is 850℃, the holding time is 20 min, the wire travel speed is 1 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0064] Step 500: Repeat step 300 with the wire, drawing it 4 times to reduce the Φ4.2mm wire to Φ3.0mm. Then, perform step 400 again to obtain the finished wire.

[0065] The ultrasonic frequency used in the cleaning process is 80kHz, the travel speed is 1.2m / min, and the cleaning medium is a weakly alkaline cleaning agent.

[0066] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min. The heating temperature is 840℃, the holding time is 20 min, the wire travel speed is 1.2 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0067] The microstructure of the 3.0mm TA15 wire prepared in this embodiment was observed, and the microstructure results are as follows: Figure 3As shown, the grains are uniform and fine. The mechanical properties of the prepared Φ3.0mm TA15 wire were tested. Six test points were selected on the prepared TA15 wire (the six test points were selected separately) to test the tensile strength, yield strength, elongation and reduction of area. The results are shown in Table 1. It can be seen from Table 1 that the various mechanical properties of the wire are consistent and stable.

[0068] Table 1. Test results of mechanical properties of annealed TA15 wire with a diameter of Φ3.0mm.

[0069]

[0070] Example 2

[0071] In this embodiment, 2.0 mm TA15 titanium alloy wire is prepared using 8.5 mm TA15 titanium alloy coils.

[0072] Step 100: The microstructure of TA15 disks is mainly α-equiaxed, with an average α grain size of 10~20 μm. The TA15 titanium alloy disks are composed of the following chemical composition by weight percentage: Al: 6.8 wt%, Zr: 2.1 wt%, Mo: 0.8 wt%, V: 0.9 wt%, Fe: 0.012 wt%, C: 0.02 wt%, H: 0.0029 wt%, O: 0.036 wt%, N: 0.024 wt%, Si: 0.003 wt%, with the balance being Ti and unavoidable impurities.

[0073] Step 200: The coil from Step 100 is subjected to a forging-skinning-polishing process. Specifically,

[0074] Step 210: The titanium alloy disc is forged at room temperature using a rotary forging method. The rotary forging speed is 8 m / min, the rotary forging deformation is 11%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm ± 0.05 mm.

[0075] Step 220: The forged coil is peeled off by turning. The turning tool speed is 1050 r / min, the peeling speed is 8 m / min, the linear speed is 28.5 m / min, the peeling amount is 0.5 mm, and the size after peeling is Φ7.5 mm ± 0.05 mm.

[0076] Step 230: Polish the peeled disc using a belt polisher. The belt mesh size is 320 or 480, the polishing speed is 8 m / min, the polishing frequency is 23 Hz, and the polishing amount is 0.01 mm.

[0077] Step 300: Apply drawing lubricant evenly to the bright filament obtained in step 200, and then perform roller drawing.

[0078] The oil-based lubricant consists of 60% thioolefins, 10% sorbitan monooleate, 5% carboxylic acid ethers, 1% bactericide, and the remainder is base oil. The oil-based lubricant is diluted with deionized water at a ratio of 1:9, and the diluted product is used as a drawing lubricant.

[0079] The roller mold is made of cemented carbide, with the main components being Mn: 2.6wt%, W: 8.8wt%, Co: 0.85wt%, Cr: 0.02wt%, Cu: 0.25wt%, S: 0.45wt%, and the balance being Fe and unavoidable impurities.

[0080] Among them, a six-pass continuous roller drawing machine is used to draw Φ7.6mm bright wire to Φ4.2mm in 6 passes, with a drawing speed of 150m / min.

[0081] Step 400: Perform continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0082] The drawn wires are first subjected to online ultrasonic cleaning and then online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 3m / min, and the cleaning medium is a weakly alkaline cleaning agent.

[0083] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min. The heating temperature is 850℃, the holding time is 15 min, the wire travel speed is 3 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0084] Step 500: Repeat step 300 with the wire, drawing it 6 times to reduce the Φ4.2mm wire to Φ2.0mm. Then, perform step 400 again to obtain the finished wire.

[0085] The ultrasonic frequency during cleaning is 80kHz, the travel speed is 4m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0086] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min. The heating temperature is 840℃, the holding time is 15 min, the wire travel speed is 3 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0087] The microstructure of the 2.0mm TA15 wire prepared in this embodiment was observed, and the microstructure results are as follows: Figure 4As shown, its structure has been fully broken down and refined, with uniform and fine grains. Mechanical properties of the prepared Φ2.0mm TA15 wire were tested. Six test points were selected on the prepared TA15 wire (the six test points were selected separately), and tensile strength, yield strength, elongation, and reduction of area were tested respectively. The results are shown in Table 2. Table 2 shows that the various mechanical properties of the wire are consistent and stable.

[0088] Table 2. Test results of mechanical properties of annealed TA15 wire with a diameter of Φ2.0mm

[0089]

[0090] As can be seen from the above embodiments, the present invention not only increases the single-pass drawing deformation, improves the drawing speed, reduces the number of heat treatments, improves the material yield, and reduces the production cost, but also produces finished wires with consistent and stable mechanical properties.

[0091] Comparative Example 1

[0092] This comparative example uses cold drawing to prepare 3.0mm TA15 titanium alloy wire. The preparation process is the same as in Example 1, except that the roller die in step 300 is a two-group three-roll symmetrical type, and the lubricant is a water-soluble lubricant.

[0093] Step 100: Prepare TA15 disks with a microstructure dominated by α-equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disks are composed of the following chemical composition by weight percentage: Al: 6.4 wt%, Zr: 2.0 wt%, Mo: 0.9 wt%, V: 1.3 wt%, Fe: 0.015 wt%, C: 0.014 wt%, H: 0.0025 wt%, O: 0.034 wt%, N: 0.022 wt%, Si: 0.004 wt%, with the balance being Ti and unavoidable impurities.

[0094] Step 200: Perform a forging-skinning-polishing process on the coil from Step 100. Specifically,

[0095] Step 210: The titanium alloy disc is forged at room temperature using a rotary forging method. The rotary forging speed is 5 m / min, the rotary forging deformation is 10%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm ± 0.05 mm.

[0096] Step 220: The forged coil is peeled off by turning. The turning tool speed is 1000 r / min, the peeling speed is 5 m / min, the linear speed is 28 m / min, the peeling amount is 0.4 mm, and the size after peeling is Φ7.6 mm ± 0.05 mm.

[0097] Step 230: Polish the peeled disc using a belt polisher. The belt mesh size is 240 or 320, the polishing speed is 5 m / min, the polishing frequency is 20 Hz, and the polishing amount is 0.01 mm.

[0098] Step 300: Apply a water-soluble lubricant evenly to the bright filament material obtained in step 200, and then perform roller drawing.

[0099] Among them, a six-pass continuous roller drawing machine is used to draw Φ7.6mm bright wire to Φ6.0mm in three passes at a drawing speed of 50m / min.

[0100] Step 400: Perform continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0101] The drawn wires are first subjected to online ultrasonic cleaning and then online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1m / min, and the cleaning medium is a weakly alkaline cleaning agent.

[0102] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min, a heating temperature of 850℃, a holding time of 20 min, a wire travel speed of 1 m / min, and rapid cooling using argon gas blowing.

[0103] Step 500: Repeat step 300, drawing the wire for 3 passes to draw the Φ6.0mm wire to Φ4.6mm. Then repeat step 400 to obtain annealed wire. Repeat step 300 again, drawing for 3 passes to draw the Φ4.6mm wire to Φ3.8mm. Finally, repeat step 400 to obtain annealed wire. Repeat step 300 again, drawing for 3 passes to draw the Φ3.8mm wire to Φ3.0mm. Then, perform step 400 again to obtain the finished wire.

[0104] The ultrasonic frequency used in the cleaning process is 80kHz, the travel speed is 1.2m / min, and the cleaning medium is a weakly alkaline cleaning agent.

[0105] The protective gas used during heating is 99.999% high-purity argon, with an argon flow rate of 15 L / min. The heating temperature is 840℃, the holding time is 20 min, the wire travel speed is 1.2 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0106] The microstructure of the 3.0mm TA15 wire prepared in this comparative example was observed, and the microstructure results are as follows: Figure 5As shown, its structure uniformity is poor. Mechanical properties of the prepared Φ3.0mm TA15 filament were tested. Six test points were selected on the prepared TA15 filament (the six test points were selected separately), and tensile strength, yield strength, elongation, and reduction of area were tested respectively. The results are shown in Table 3. Table 3 shows that the tensile strength of the filament increased, the elongation decreased, and the overall mechanical properties of the filament deteriorated.

[0107] Table 3. Test results of mechanical properties of annealed TA15 wire with a diameter of 3.0mm.

[0108]

[0109] Comparative Example 2

[0110] This comparative example uses hot drawing to prepare Φ3.0mm TA15 titanium alloy wire. The preparation process is the same as in Example 1, except that the roll drawing in step 500 is replaced with hot drawing.

[0111] Step 100: Prepare TA15 disks with a microstructure dominated by α-equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disks are composed of the following chemical composition by weight percentage: Al: 6.7 wt%, Zr: 2.0 wt%, Mo: 1.0 wt%, V: 0.9 wt%, Fe: 0.014 wt%, C: 0.015 wt%, H: 0.0024 wt%, O: 0.037 wt%, N: 0.020 wt%, Si: 0.003 wt%, with the balance being Ti and unavoidable impurities.

[0112] Step 200: The coil from Step 200 undergoes a forging-skinning-polishing process. Specifically,

[0113] Step 210: The titanium alloy disc is forged at room temperature using a rotary forging method. The rotary forging speed is 5 m / min, the rotary forging deformation is 10%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm ± 0.05 mm.

[0114] Step 220: The forged coil is peeled off by turning. The turning tool speed is 1000 r / min, the peeling speed is 5 m / min, the linear speed is 28 m / min, the peeling amount is 0.4 mm, and the size after peeling is Φ7.6 mm ± 0.05 mm.

[0115] Step 230: Polish the peeled disc using a belt polisher. The belt mesh size is 240 or 320, the polishing speed is 5 m / min, the polishing frequency is 20 Hz, and the polishing amount is 0.01 mm.

[0116] Step 300: The intermediate wire obtained in Step 200 is reduced in diameter by hot drawing at a heating temperature of 820℃ and a drawing speed of 10m / min. Graphite emulsion is used as the drawing lubricant. The diameter is reduced to Φ3.10mm in 18 passes.

[0117] Step 400: Peel the Φ3.10mm wire obtained in step 300 to reduce the Φ3.10mm wire to Φ3.0mm.

[0118] Step 500: Perform a solution treatment on the filaments that have been peeled in Step 400.

[0119] The process employs an online protective atmosphere heat treatment furnace. During heating, the protective gas is 99.999% high-purity argon with a flow rate of 15 L / min. The heating temperature is 840℃, the holding time is 20 min, the wire travel speed is 1.2 m / min, and the cooling method is rapid argon blowing with a cooling rate of 150℃ / s to 180℃ / s.

[0120] The microstructure of the 3.0mm TA15 wire prepared in this comparative example was observed, and the microstructure results are as follows: Figure 6 As shown, its structure is coarse and has poor uniformity. Mechanical properties of the prepared Φ3.0mm TA15 filament were tested. Six test points were selected on the prepared TA15 filament (the six test points were selected separately), and tensile strength, yield strength, elongation, and reduction of area were tested respectively. The results are shown in Table 4. Table 4 shows that the tensile strength of the filament increased, the elongation decreased, and the overall mechanical properties of the filament deteriorated.

[0121] Table 4. Test results of mechanical properties of annealed TA15 wire with a diameter of 3.0mm.

[0122]

[0123] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the present invention.

[0124] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of the present invention is limited to these examples; within the framework of the embodiments of the present invention, the technical features of the above embodiments or different embodiments can also be combined, and there are many other variations of different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of the present invention should be included within the protection scope of the embodiments of the present invention.

Claims

1. A method for preparing high-strength TA15 titanium alloy wire at low cost, characterized in that, Includes the following steps: S100, prepare TA15 titanium alloy disks, wherein the metallographic structure of the TA15 titanium alloy disks contains α equiaxed crystals and the average grain size is 10~20μm; S200, the TA15 titanium alloy wire rod is processed by rounding, peeling, and polishing to obtain a bright-surfaced wire rod, including: S210, the titanium alloy wire rod is forged at room temperature using a rotary forging method, wherein the rotary forging speed is controlled at 5~10m / min, the rotary forging deformation is 10%~12%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0mm±0.05mm; S220, the forged wire rod is peeled by turning, wherein the turning tool speed is controlled at 1000~1000 rpm. 200 r / min, peeling speed of 5~7 m / min, linear speed of 28~30 m / min, peeling amount of 0.4~0.6 mm, and post-peeling size of Φ7.5 mm ± 0.05 mm; S230, the peeled wire rod is polished using a belt polisher to obtain a bright surface wire rod. The belt mesh size is selected as 240 mesh, 320 mesh, and 480 mesh, the polishing speed is 5~7 m / min, the polishing frequency is 20~25 Hz, and the polishing amount is 0.01~0.02 mm; S300, the coiled wire is subjected to multiple roller drawing processes to obtain drawn wire. The roller die is made of cemented carbide with the following composition: Mn: 2.2 wt%~3.0 wt%, W: 8.0 wt%~9.0 wt%, Co≤0.2 wt%, Cr≤0.2 wt%, Cu≤0.5 wt%, S≤0.5 wt%, and the balance being Fe and unavoidable impurities. The wire exit accuracy of each pass is controlled within ±0.02 mm, the drawing speed is 120~180 m / min, and the deformation per drawing pass is 15%. After each 5~6 cumulative diameter reductions of the bright coiled wire, annealing heat treatment is performed, and the cumulative deformation is controlled to be 50%~60%, thus obtaining the drawn wire. S400, the drawn wire is subjected to an online heat treatment to obtain a fully annealed wire; S500, repeat steps S300 and S400 to obtain the finished wire material.

2. The method according to claim 1, characterized in that, In step S100, TA15 ingots are obtained by three vacuum self-consumption melting processes, and titanium alloy discs with a diameter of Φ8.5mm are obtained by forging and rolling.

3. The method according to claim 2, characterized in that, In step S100, The TA15 titanium alloy discs are composed of the following weight percentages: Al: 6.0wt%~7.0wt%, Zr: 1.5wt%~2.5wt%, Mo: 1.5wt%~2wt%, V: 1.5wt%~2wt%, Fe≤0.03wt%, C≤0.02wt%, H≤0.005wt%, O≤0.05wt%, N≤0.03wt%, Si≤0.01wt%, with the balance being Ti and unavoidable impurities.

4. The method according to claim 1, characterized in that, In step S300, The drawing equipment is a six-pass cold drawing machine, which simultaneously installs six sets of dies for drawing; The roller mold has a two-roll symmetrical structure, consisting of eight sets of rollers; Among them, the eight sets of rollers are arranged in a horizontal + vertical + horizontal + vertical + horizontal + vertical + horizontal + vertical manner; The first six sets of rollers are deformation rollers, and the last two sets of rollers are shaping rollers.

5. The method according to claim 1, characterized in that, In step S300, an oil-based lubricant is used for lubrication; The oily lubricant, by volume percentage, comprises: 50% to 70% thioolefins, 1% to 10% sorbitan monooleate, 1% to 5% carboxylic acid ethers, 0.1% to 1% bactericides, and the remainder being base oils. The oily lubricant is diluted with deionized water at a volume ratio of 1:8 to 1:10, and the diluted product is used as a drawing lubricant.

6. The method according to claim 1, characterized in that, In step S400, the drawn wire is cleaned of lubricant on the surface by online ultrasonic cleaning before heat treatment, with the ultrasonic frequency controlled at 80~100kHz and the travel speed at 5~10m / min.

7. The method according to claim 1, characterized in that, In step S400, Online heat treatment uses 99.999% high-purity argon as the protective gas, and controls the argon flow rate to be 15~20L / min; The heat treatment temperature is controlled at 850℃, the holding time is 5~10min, the wire travel speed is 5~10m / min, and the cooling method is argon gas blowing cooling, with a cooling rate of 150℃ / s~180℃ / s.

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