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

Abstract

The invention relates to the technical field of wire material preparation, and particularly discloses a low-cost method for preparing a high-strength TA15 titanium alloy wire material, which comprises the following steps: S100, preparing a TA15 titanium alloy wire rod; s200, the TA15 titanium alloy wire rod is subjected to rounding-peeling-polishing procedure treatment, and a wire rod with the bright surface is obtained; s300, the coiled wire is subjected to multi-pass roller die drawing treatment, and a drawn wire material is obtained; s400, carrying out one-time online heat treatment on the drawn wire to obtain a completely annealed wire; and S500, the step S300 and the step S400 are repeatedly executed, and a finished wire is obtained. According to the method, the TA15 titanium alloy wire drawing deformation, the drawing speed and the die service life can be greatly improved, the material loss is reduced, the wire product stability and consistency are improved, the material processing cost is finally reduced, and the wire product quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of wire material preparation, and in particular to a method for preparing high-strength TA15 titanium alloy wire material at low cost. Background Art

[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 α-type and α+β-type titanium alloys, with good plasticity, excellent welding performance and thermal stability. In high temperature environments, it exhibits excellent creep resistance and endurance strength, and can work stably for a long time at temperatures up to 500°C. Therefore, TA15 titanium alloy can be processed into various forms such as plates, bars, wires and forgings, becoming an important structural material in many fields. Especially in the manufacture of aircraft structures and engines, it has been widely used.

[0003] However, while TA15 titanium alloy has many advantages, it also faces some challenges. Due to its high tensile strength and deformation resistance, TA15 titanium alloy wire has problems such as small single drawing deformation, slow drawing speed, short die life, large peeling loss after repeated hot working, and unstable process flow during the preparation process, resulting in high processing costs for TA15 titanium alloy wire, which limits 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] In view of the shortcomings of the prior art, the main purpose of the present invention is to provide a method for preparing high-strength TA15 titanium alloy wire at a low cost, which can greatly improve the drawing deformation, drawing speed, and die life of TA15 titanium alloy wire, reduce material loss, improve the stability and consistency of wire products, and ultimately reduce material processing costs and ensure the quality of wire products.

[0006] In order to solve at least one of the above technical problems, the present invention adopts the following technical solution: According to the present invention, a method for preparing high-strength TA15 titanium alloy wire at low cost is provided, which includes the following steps: S100, preparing a TA15 titanium alloy coil, wherein the metallographic structure of the TA15 titanium alloy coil contains α equiaxed crystals, and the average grain size is 10-20 μm; S200, performing a rounding-peeling-polishing process on the above TA15 titanium alloy coil to obtain a wire coil with a bright surface; S300, performing multi-pass roller die drawing on the wire coil to obtain a drawn wire; S400, performing one-time online heat treatment on the drawn wire to obtain a fully annealed wire; S500, repeating steps S300 and S400 to obtain a finished wire.

[0007] According to an embodiment of the present invention, in step S100, a TA15 ingot is obtained by three times of vacuum consumable melting, and a titanium alloy coil with a diameter of Φ8.5 mm is obtained by forging and rolling.

[0008] According to an embodiment of the present invention, in step S100, the TA15 titanium alloy coil is composed of chemical components with the following weight percentages: Al: 6.0 wt% - 7.0 wt%, Zr: 1.5 wt% - 2.5 wt%, Mo: 0.5 wt% - 1.5 wt%, V: 0.5 wt% - 1.5 wt%, Fe ≤ 0.03 wt%, C ≤ 0.02 wt%, H ≤ 0.005 wt%, O ≤ 0.05 wt%, N ≤ 0.03 wt%, Si ≤ 0.01 wt%, and the balance is Ti and unavoidable impurities.

[0009] According to an embodiment of the present invention, step S200 includes: S210, performing room-temperature rotary forging on the titanium alloy bar by means of rotary forging, wherein the rotary forging speed is controlled to be 5-10 m / min, the rotary forging deformation amount is 10%-12%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm ± 0.05 mm; S220, peeling the rotary-forged bar by means of turning, wherein the turning tool speed is controlled to be 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; S230, polishing the peeled bar by means of a sand belt polishing machine to obtain a wire coil with a bright surface, wherein the sand belt mesh number is selected as 240 mesh, 320 mesh, 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.

[0010] According to one embodiment of the present invention, in step S300, the drawing equipment is a six-pass cold drawing machine, and six groups of molds are installed at the same time for drawing; the wheel type of the roller mold is a two-roller symmetrical structure, consisting of eight groups of rollers; wherein, the eight groups of rollers are arranged in a horizontal + vertical + horizontal + vertical + horizontal + vertical + horizontal + vertical manner; wherein, the first six groups of rollers are deforming rollers, and the last two groups of rollers are shaping rollers.

[0011] 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%~3.0wt%, W: 8.0 wt%~9.0wt%, Co≤0.2wt%, Cr≤0.2wt%, Cu≤0.5wt%, S≤0.5wt%, and the remainder is Fe and unavoidable impurities.

[0012] According to one embodiment of the present invention, in step S300, an oily lubricant is used for lubrication; wherein, in terms of volume percentage, the oily lubricant comprises: 50% to 70% thioene, 1% to 10% sorbitan monooleate, 1% to 5% carboxylic acid ether, 0.1% to 1% bactericide, and the rest is base oil; wherein, the oily lubricant is diluted with deionized water in a volume ratio of 1:8 to 1:10, and is used as a drawing lubricant after dilution.

[0013] According to one embodiment of the present invention, in step S300, the wire outlet accuracy of each pass is controlled to be within ±0.02mm, the drawing speed is 120-180m / min, the deformation of a single drawing pass is 15%, and the bright wire is annealed and heat treated after each cumulative diameter reduction of 5-6 times, and the cumulative deformation is controlled to be 50%-60% to obtain the drawn wire.

[0014] 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 to be 80-100 kHz and the travel speed is 5-10 m / min.

[0015] 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 the argon flow rate is controlled to be 15~20L / min; the heat treatment temperature is controlled to be 850°C, the holding time is 5~10min, the wire travel speed is 5~10m / min, and the cooling method adopts argon gas blowing cooling, and the cooling rate is 150°C / s~180°C / s.

[0016] By adopting the above technical solution, the present invention has at least one of the following advantages compared with the prior art: (1) The present 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 increase the service life of the roller die, but also provide strong support for the subsequent large deformation and diameter reduction of the titanium wire.

[0017] (2) The present invention uses eight groups of two-roller symmetrical structure roller dies for cold drawing. Compared with the conventional two groups of three-roller symmetrical structure roller dies, it has higher single-pass deformation, deformation uniformity and deformation smoothness. The large deformation of the roller die can fully break the internal structure of the wire, improve the structure performance, and increase the product qualification rate. At the same time, the roller die can draw in multiple passes at the same time, which can not only reduce the threading time, but also the large deformation can increase the total deformation, reduce the number of heat treatments, and improve production efficiency. The drawing cost of TA15 wire is reduced to 50% of the original cost.

[0018] (3) The present invention adopts an oily lubricant, which is designed according to a formula for heavy-load processing and is compatible with cemented carbide dies. It can lubricate the roller die under high-speed and large-deformation drawing conditions, thereby extending the life of the die and providing strong support for large-deformation drawing of TA15 wire.

[0019] (4) Compared with the offline vacuum heat treatment equipment, the online heat treatment equipment used in the present invention can ensure that the drawn wire has a large amount of distortion energy and generates a large number of nucleation particles during recrystallization, thereby achieving the purpose of grain refinement. In addition, the solution treatment can effectively reduce the heating temperature, prevent the abnormal growth of the grain structure, and help control the uniformity and consistency of the wire structure. At the same time, the online heat treatment can improve the degree of automation of the entire wire drawing preparation process, greatly reduce labor and preparation time, and help reduce the processing cost of TA15 wire.

[0020] (5) Compared with the traditional hot drawing process, the present invention uses cold processing throughout the entire process. No peeling is required before the finished product is produced, which can save 10% to 15% of the material loss rate and further reduce the processing cost of TA15 wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the steps of a method for preparing a high-strength TA15 titanium alloy wire at low cost according to an embodiment of the present invention; Figure 2 The microstructure diagram of the TA15 titanium alloy wire rod with a specification of Φ8.5 mm according to an embodiment of the present invention; Figure 3 This is a microstructure diagram of a TA15 titanium alloy wire with a diameter of Φ3.0 mm according to Example 1 of the present invention; Figure 4 This is a microstructure diagram of a TA15 titanium alloy wire with a diameter of 2.0 mm according to Example 2 of the present invention; Figure 5 This is a microstructure diagram of a TA15 titanium alloy wire with a diameter of Φ3.0 mm according to Comparative Example 1 of the present invention; Figure 6 This is a microstructure diagram of a TA15 titanium alloy wire with a diameter of Φ3.0 mm according to comparative example 2 of the present invention. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0024] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0025] The present invention provides a method for preparing high-strength TA15 titanium alloy wire at low cost. Figure 1 As shown, the method generally includes the following steps: S100, preparing a TA15 titanium alloy disk, wherein the metallographic structure of the TA15 titanium alloy disk comprises α equiaxed crystals and an average grain size of 10 to 20 μm; S200, performing a rounding-stripping-polishing process on the TA15 titanium alloy coil to obtain a coiled wire with a bright surface; S300, performing a roller die drawing process on the coiled wire in multiple passes to obtain a drawn wire material; S400, performing an online heat treatment on the drawn wire to obtain a completely annealed wire; S500, repeating steps S300 and S400 to obtain a finished wire material.

[0026] Step S100 uses three vacuum consumable smelting to obtain a TA15 ingot, and forging and rolling to obtain a titanium alloy disc of appropriate diameter. In an embodiment of the present invention, the TA15 titanium alloy disc can be composed of the following chemical components in 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%, and the balance is Ti and unavoidable impurities. In other embodiments, those skilled in the art can use the teachings disclosed herein to seek to obtain the desired properties and appropriately change the values ​​of each element. It should be understood that the use of a numerical range represented by an endpoint includes all numbers within the range and any range within the range. The metallographic structure of the prepared TA15 titanium alloy disk contains α equiaxed crystals, and the average grain size is preferably 10-20 μm. Figure 2 shown.

[0027] In step S200, before cold drawing, the titanium coil prepared in step S100 can be subjected to rotary forging, peeling and polishing to obtain a coil with a bright surface. Taking a titanium alloy coil with a diameter of Φ8.5 mm as an example, the drawing process may specifically include: S210, rotary forging the titanium alloy wire rod at room temperature by rotary forging, wherein the rotary forging speed is controlled to be 5-10 m / min, the rotary forging deformation is 10%-12%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm±0.05 mm; S220, the wire rod after rotary forging is peeled by turning, wherein the turning tool speed is controlled to be 1000~1200r / min, the peeling speed is 5~7m / min, the line speed is 28~30m / min, the peeling amount is 0.4~0.6mm, and the size after peeling is Φ7.5mm±0.05mm; S230, uses a sand belt polisher to polish the peeled wire rod to obtain a wire with a bright surface, wherein the sand belt mesh is selected to be 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.

[0028] In step S300, the drawing equipment is a six-pass cold drawing machine, and six groups of dies are installed at the same time for drawing; the wheel type of the roller die is a two-roller symmetrical structure, consisting of eight groups of rollers. Among them, the eight groups of rollers are arranged in a horizontal + vertical + horizontal + vertical + horizontal + vertical + horizontal + vertical manner: the first six groups of rollers are deforming rollers, and the last two groups of rollers are shaping rollers. The material of the roller die is preferably cemented carbide, which has excellent properties of wear resistance, pressure resistance, and high temperature resistance, effectively improving production efficiency and product quality. In an embodiment of the present 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%, and the remainder is Fe and unavoidable impurities.

[0029] Furthermore, in step S300, an oily lubricant is used for lubrication. In an embodiment of the present invention, the oily lubricant may include, by volume percentage: 50% to 70% thioene, 1% to 10% sorbitan monooleate, 1% to 5% carboxylic acid ether, 0.1% to 1% bactericide, and the rest is base oil. The above oily lubricant may be diluted with deionized water at a volume ratio of 1:8 to 1:10, and used as a drawing lubricant after dilution.

[0030] Furthermore, in the drawing process of step S300, the wire outlet accuracy of each pass is preferably controlled within ±0.02mm, the drawing speed is 120-180m / min, the deformation of a single drawing pass is 15%, and the bright wire is annealed and heat treated after 5-6 cumulative diameter reductions, and the cumulative deformation is controlled to be 50%-60% to obtain a drawn wire.

[0031] In step S400, the surface lubricant of the drawn wire can be cleaned by online ultrasonic cleaning before heat treatment. It is preferred to control the ultrasonic frequency to 80~100kHz and the travel speed to 5~10m / min. The wire after ultrasonic cleaning is completely annealed by continuous online heat treatment. Specifically, 99.999% high-purity argon is used as the protective gas, and the argon flow rate is controlled 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 adopts argon gas blowing cooling, and the cooling rate is 150℃ / s~180℃ / s.

[0032] In step S500, steps S300 and S400 are repeatedly performed according to the size of the finished product, and finally the Φ8.5 mm coil is drawn into a finished wire material with a specification of Φ3.0-Φ1.6 mm.

[0033] Through the above technical scheme, the present invention starts from the wire deformation process, optimizes the structure of the roller die, adopts a new lubricant, and combines a large deformation with a 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 ultimately achieves the purpose of preparing high-strength titanium alloy wire at high speed, large deformation and low cost.

[0034] The following are specific embodiments of the high-strength TA15 titanium alloy wire and the preparation method thereof according to the present invention and their specific process parameters.

[0035] Example 1 In this embodiment, TA15 titanium alloy coil with a diameter of Φ8.5 mm is used to prepare TA15 titanium alloy wire with a diameter of Φ3.0 mm.

[0036] Step 100: Prepare a TA15 disk with a microstructure dominated by an α equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disk is composed of the following weight percentages of 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%, and the balance is Ti and unavoidable impurities.

[0037] Step 200: The coil of step 100 is subjected to a rotary forging-skinning-polishing process. Specifically, Step 210: Forging the titanium alloy disc at room temperature by rotary forging, with a rotary forging speed of 5 m / min, a rotary forging deformation of 10%, an industrial lubricating oil as lubricant, and a size of Φ8.0 mm±0.05 mm after rotary forging; Step 220: peeling the disc after rotary forging by turning, with a turning tool speed of 1000 r / min, a peeling speed of 5 m / min, a linear speed of 28 m / min, a peeling amount of 0.4 mm, and a size of Φ7.6 mm±0.05 mm after peeling; Step 230: Use a sand belt polisher to polish the peeled disc, the sand belt mesh size is 240 mesh and 320 mesh, the polishing speed is 5m / min, the polishing frequency is 20Hz, and the polishing amount is 0.01mm.

[0038] Step 300: evenly apply a drawing lubricant to the bright wire obtained in step 200, and then perform roller die drawing.

[0039] The oil lubricant is composed of 70% thioene, 5% sorbitan monooleate, 1% carboxylic acid ether, 1% bactericide, and the rest is base oil. The oil lubricant is diluted with deionized water at a ratio of 1:10 and used as a drawing lubricant after dilution.

[0040] Among them, the roller die is made of cemented carbide, and its main components are Mn: 2.5wt%, W: 8.5wt%, Co: 0.78wt%, Cr: 0.01wt%, Cu: 0.18wt%, S≤0.32wt%, and the remainder is Fe and inevitable impurities.

[0041] Among them, a six-pass continuous roller die drawing machine is used to draw the Φ7.6mm bright wire in 6 passes to Φ4.2mm, and the drawing speed is 150m / min.

[0042] Step 400: performing a continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0043] The drawn wire is firstly subjected to online ultrasonic cleaning and then to online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0044] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 850℃, the insulation time is 20min, the wire travel speed is 1m / min, and the cooling method is argon gas blowing fast cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0045] Step 500: Repeat step 300 for the wire, draw 4 times, and draw the Φ4.2 mm wire to Φ3.0 mm. Then, perform step 400 again to obtain the finished wire.

[0046] The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1.2m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0047] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 840℃, the insulation time is 20min, the wire travel speed is 1.2m / min, and the cooling method is argon gas blowing fast cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0048] The microstructure of the Φ3.0 mm TA15 wire prepared in this embodiment was observed, and the microstructure results are as follows: Figure 3The mechanical properties of the prepared Φ3.0 mm TA15 wire were tested. Six test points (six test points were selected separately) were selected from the prepared TA15 wire to test the tensile strength, yield strength, elongation and cross-sectional shrinkage. The results are shown in Table 1. It can be seen from Table 1 that the mechanical properties of the wire are consistent and stable.

[0049] Table 1 Mechanical properties test results of Φ3.0mm annealed TA15 wire

[0050] Example 2 In this embodiment, TA15 titanium alloy coil with a diameter of Φ8.5 mm is used to prepare TA15 titanium alloy wire with a diameter of Φ2.0 mm.

[0051] Step 100: Prepare a TA15 disk with a microstructure dominated by α equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disk is composed of the following chemical components in weight percentage: Al: 6.8wt%, Zr: 2.1wt%, Mo: 0.8wt%, V: 0.9wt%, Fe: 0.012wt%, C: 0.02wt%, H: 0.0029wt%, O: 0.036wt%, N: 0.024wt%, Si: 0.003wt%, and the balance is Ti and unavoidable impurities.

[0052] Step 200: The coil of step 100 is subjected to a rotary forging-skinning-polishing process. Specifically, Step 210: rotary forging the titanium alloy disc at room temperature, with a rotary forging speed of 8 m / min, a rotary forging deformation of 11%, an industrial lubricating oil as lubricant, and a size of Φ8.0 mm±0.05 mm after rotary forging; Step 220: peeling the disc after rotary forging by turning, with a turning tool speed of 1050 r / min, a peeling speed of 8 m / min, a linear speed of 28.5 m / min, a peeling amount of 0.5 mm, and a size of Φ7.5 mm±0.05 mm after peeling; Step 230: Use a sand belt polisher to polish the peeled disc, the sand belt mesh size is 320 mesh and 480 mesh, the polishing speed is 8m / min, the polishing frequency is 23Hz, and the polishing amount is 0.01mm.

[0053] Step 300: evenly apply a drawing lubricant to the bright wire obtained in step 200, and then perform roller die drawing.

[0054] The composition of the oily lubricant is 60% thioene, 10% sorbitan monooleate, 5% carboxylic acid ether, 1% bactericide, and the rest is base oil. The oily lubricant is diluted with deionized water at a ratio of 1:9 and used as a drawing lubricant after dilution.

[0055] Among them, the roller die is made of cemented carbide, and its main components are Mn: 2.6wt%, W: 8.8wt%, Co: 0.85wt%, Cr: 0.02wt%, Cu: 0.25wt%, S: 0.45wt%, and the remainder is Fe and inevitable impurities.

[0056] Among them, a six-pass continuous roller die drawing machine is used to draw the Φ7.6mm bright wire in 6 passes to Φ4.2mm, and the drawing speed is 150m / min.

[0057] Step 400: performing a continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0058] The drawn wire is firstly subjected to online ultrasonic cleaning and then to online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 3m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0059] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 850℃, the insulation time is 15min, the wire travel speed is 3m / min, and the cooling method is argon gas blowing fast cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0060] Step 500: Repeat step 300 for the wire, draw 6 times, and draw the Φ4.2 mm wire to Φ2.0 mm. Then, perform step 400 again to obtain the finished wire.

[0061] The ultrasonic frequency during cleaning is 80kHz, the travel speed is 4m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0062] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 840℃, the insulation time is 15min, the wire travel speed is 3m / min, and the cooling method is argon gas blowing fast cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0063] The microstructure of the Φ2.0 mm TA15 wire prepared in this embodiment was observed, and the microstructure results are as follows: Figure 4As shown in Table 2, its organization has been fully broken and refined, and the grains are uniform and small. The mechanical properties of the prepared Φ2.0mm TA15 wire were tested. Six test points (six test points were selected separately) were selected from the prepared TA15 wire to test the tensile strength, yield strength, elongation and cross-sectional shrinkage. The results are shown in Table 2. It can be seen from Table 2 that the mechanical properties of the wire are consistent and stable.

[0064] Table 2 Mechanical properties test results of Φ2.0mm annealed TA15 wire

[0065] It can be seen from the above embodiments that 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 rate, and reduces production costs, but also produces finished wires with consistent and stable mechanical properties.

[0066] Comparative Example 1 This comparative example adopts cold drawing to prepare Φ3.0 mm TA15 titanium alloy wire. The preparation process is the same as that of Example 1, except that the roller mold in step 300 is a two-group three-roller symmetrical type, and the lubricant is a water-soluble lubricant.

[0067] Step 100: Prepare a TA15 disk with a microstructure dominated by an α equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disk is composed of the following chemical components in weight percentage: Al: 6.4wt%, Zr: 2.0wt%, Mo: 0.9wt%, V: 1.3wt%, Fe: 0.015wt%, C: 0.014wt%, H: 0.0025wt%, O: 0.034wt%, N: 0.022wt%, Si: 0.004wt%, and the balance is Ti and unavoidable impurities.

[0068] Step 200: The disk produced in step 100 is subjected to a process of rotary forging, peeling and polishing. Specifically, Step 210: Forging the titanium alloy disc at room temperature by rotary forging, with a rotary forging speed of 5 m / min, a rotary forging deformation of 10%, an industrial lubricating oil as lubricant, and a size of Φ8.0 mm±0.05 mm after rotary forging; Step 220: peeling the disc after rotary forging by turning, with a turning tool speed of 1000 r / min, a peeling speed of 5 m / min, a linear speed of 28 m / min, a peeling amount of 0.4 mm, and a size of Φ7.6 mm±0.05 mm after peeling; Step 230: Use a sand belt polisher to polish the peeled disc, the sand belt mesh size is 240 mesh and 320 mesh, the polishing speed is 5m / min, the polishing frequency is 20Hz, and the polishing amount is 0.01mm.

[0069] Step 300: evenly apply a water-soluble lubricant to the bright wire obtained in step 200, and then perform roller die drawing.

[0070] Among them, a six-pass continuous roller die drawing machine is used to draw the Φ7.6mm bright wire in three passes to Φ6.0mm, and the drawing speed is 50m / min.

[0071] Step 400: performing a continuous online heat treatment in a protective atmosphere on the drawn wire obtained in step 300.

[0072] The drawn wire is firstly subjected to online ultrasonic cleaning and then to online heat treatment. The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0073] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 850°C, the insulation time is 20min, the wire travel speed is 1m / min, and the cooling method is argon gas blowing rapid cooling.

[0074] Step 500: Repeat step 300 for the wire, draw 3 times, draw the Φ6.0 mm wire to Φ4.6 mm, then repeat step 400 to obtain the annealed wire, repeat step 300 again, draw 3 times, draw the Φ4.6 mm wire to Φ3.8 mm, finally repeat step 400 to obtain the annealed wire, repeat step 300 again, draw 3 times, draw the Φ3.8 mm wire to Φ3.0 mm. Then execute step 400 again to obtain the finished wire.

[0075] The ultrasonic frequency during cleaning is 80kHz, the travel speed is 1.2m / min, and the cleaning medium is a weak alkaline cleaning agent.

[0076] Among them, the protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 840℃, the insulation time is 20min, the wire travel speed is 1.2m / min, and the cooling method is argon gas blowing fast cooling, with a cooling rate of 150℃ / s~180℃ / s.

[0077] The microstructure of the Φ3.0 mm TA15 wire prepared in this comparative example was observed, and the microstructure results are as follows: Figure 5As shown, its organization uniformity is poor. The mechanical properties of the prepared Φ3.0mm TA15 wire were tested. Six test points (six test points were selected separately) were selected from the prepared TA15 wire to test the tensile strength, yield strength, elongation and cross-sectional shrinkage. The results are shown in Table 3. It can be seen from Table 3 that the tensile strength of the wire increases, the elongation decreases, and the comprehensive mechanical properties of the wire deteriorate.

[0078] Table 3 Mechanical properties test results of Φ3.0mm annealed TA15 wire

[0079] Comparative Example 2 In this comparative example, a 3.0 mm TA15 titanium alloy wire is prepared by hot drawing. The preparation process is the same as that of Example 1, except that the roller die drawing in step 500 is replaced by hot drawing.

[0080] Step 100: Prepare a TA15 disk with a microstructure dominated by an α equiaxed structure and an average α grain size of 10-20 μm. The TA15 titanium alloy disk is composed of the following chemical components in weight percentage: Al: 6.7wt%, Zr: 2.0wt%, Mo: 1.0wt%, V: 0.9wt%, Fe: 0.014wt%, C: 0.015wt%, H: 0.0024wt%, O: 0.037wt%, N: 0.020wt%, Si: 0.003wt%, and the balance is Ti and unavoidable impurities.

[0081] Step 200: The disk of step 200 is subjected to a process of rotary forging, peeling and polishing. Specifically, Step 210: Forging the titanium alloy disc at room temperature by rotary forging, with a rotary forging speed of 5 m / min, a rotary forging deformation of 10%, an industrial lubricating oil as lubricant, and a size of Φ8.0 mm±0.05 mm after rotary forging; Step 220: peeling the disc after rotary forging by turning, with a turning tool speed of 1000 r / min, a peeling speed of 5 m / min, a linear speed of 28 m / min, a peeling amount of 0.4 mm, and a size of Φ7.6 mm±0.05 mm after peeling; Step 230: Use a sand belt polisher to polish the peeled disc, the sand belt mesh size is 240 mesh and 320 mesh, the polishing speed is 5m / min, the polishing frequency is 20Hz, and the polishing amount is 0.01mm.

[0082] Step 300: The intermediate wire obtained in step 200 is reduced in diameter by hot drawing, with a heating temperature of 820°C, a drawing speed of 10 m / min, and graphite emulsion as a drawing lubricant. The diameter is reduced to Φ3.10 mm through 18 passes.

[0083] Step 400: Stripping the Φ3.10 mm wire obtained in step 300, and stripping the Φ3.10 mm wire to Φ3.0 mm.

[0084] Step 500: subjecting the wire stripped in step 400 to a solid solution treatment.

[0085] Among them, an online protective atmosphere heat treatment furnace is adopted. The protective gas during heating is 99.999% high-purity argon, the argon flow rate is 15L / min, the heating temperature is 840℃, the insulation time is 20min, the wire travel speed is 1.2m / min, and the cooling method is argon gas blowing fast cooling, and the cooling rate is 150℃ / s~180℃ / s.

[0086] The microstructure of the Φ3.0 mm TA15 wire prepared in this comparative example was observed, and the microstructure results are as follows: Figure 6 As shown, its organization is coarse and uniform. The mechanical properties of the prepared Φ3.0 mm TA15 wire were tested. Six test points (six test points were selected separately) were selected from the prepared TA15 wire to test the tensile strength, yield strength, elongation and cross-sectional shrinkage. The results are shown in Table 4. It can be seen from Table 4 that the tensile strength of the wire increases, the elongation decreases, and the comprehensive mechanical properties of the wire deteriorate.

[0087] Table 4 Mechanical properties test results of Φ3.0mm annealed TA15 wire

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by equivalents without departing from the spirit and scope of the present invention, it should be included in the protection scope of the present invention.

[0089] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention is limited to these examples; under the idea of ​​the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in 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: The following steps are involved: S100, preparing a TA15 titanium alloy disk, wherein the metallographic structure of the TA15 titanium alloy disk comprises α equiaxed crystals, and the average grain size is 10-20 μm; S200, performing a rounding-skinning-polishing process on the TA15 titanium alloy coil to obtain a coiled wire with a bright surface; S300, performing a roller die drawing process on the coiled wire for multiple passes to obtain a drawn wire material; S400, performing an online heat treatment on the drawn wire to obtain a completely annealed wire; S500, repeating steps S300 and S400 to obtain a finished wire material.

2. The method according to claim 1, characterized in that In step S100, a TA15 ingot is obtained by three vacuum consumable smelting processes, and a titanium alloy disc with a diameter of Φ8.5 mm is obtained by forging and rolling.

3. The method according to claim 2, characterized in that In step S100, The TA15 titanium alloy disc is 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%, and the balance is Ti and unavoidable impurities.

4. The method according to claim 2, characterized in that: Step S200 includes: S210, rotary forging the titanium alloy wire rod at room temperature by rotary forging, wherein the rotary forging speed is controlled to be 5-10 m / min, the rotary forging deformation is 10%-12%, the lubricant is industrial lubricating oil, and the size after rotary forging is Φ8.0 mm±0.05 mm; S220, the wire rod after rotary forging is peeled by turning, wherein the turning tool speed is controlled to be 1000~1200r / min, the peeling speed is 5~7m / min, the line speed is 28~30m / min, the peeling amount is 0.4~0.6mm, and the size after peeling is Φ7.5mm±0.05mm; S230, uses a sand belt polisher to polish the peeled wire rod to obtain a wire with a bright surface, wherein the sand belt mesh is selected to be 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.

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

6. The method according to claim 5, characterized in that The roller die is made of cemented carbide, and its main components are Mn: 2.2 wt%~3.0wt%, W: 8.0 wt%~9.0wt%, Co≤0.2wt%, Cr≤0.2wt%, Cu≤0.5wt%, S≤0.5wt%, and the balance is Fe and unavoidable impurities.

7. The method according to claim 6, characterized in that In step S300, lubrication is performed using an oily lubricant; Wherein, the oil lubricant comprises, by volume percentage: 50% to 70% thioene, 1% to 10% sorbitan monooleate, 1% to 5% carboxylic acid ether, 0.1% to 1% bactericide, and the rest is base oil; The oily lubricant is diluted with deionized water in a volume ratio of 1:8 to 1:10, and is used as a drawing lubricant after dilution.

8. The method according to claim 1, characterized in that In step S300, the wire outlet accuracy of each pass is controlled to be within ±0.02mm, the drawing speed is 120-180m / min, the deformation of a single drawing pass is 15%, and the bright wire is annealed and heat treated after 5-6 cumulative diameter reductions, and the cumulative deformation is controlled to be 50%-60% to obtain the drawn wire.

9. The method according to claim 1, characterized in that: 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 to be 80-100 kHz and the travel speed is 5-10 m / min.

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

Images