A method for preparing wide TA4 titanium strip

Abstract

This invention discloses a method for preparing wide TA4 titanium strip, comprising the following steps: S1, raw material batching and ingot melting; S2, ingot treatment and slab forging finishing; S3, slab hot rolling and hot wire annealing and pickling; S4, first-pass cold rolling; S5, pretreatment and second-pass cold rolling; S6, final treatment annealing, tensioning and edge trimming. This invention simplifies the cold rolling process, uses 7-pass continuous rolling for hot rolling, and replaces the traditional bell-type furnace process with annealing to produce cold-rolled bright TA4 titanium strip with a grain size of 8-10, elongation >30%, and tensile strength of 650-720MPa. This invention has a short process flow, high yield, low production cost, excellent surface quality, flat shape, and uniform microstructure and properties of the finished product, making it easy to mass-produce on an industrial scale and meet the application requirements of wide TA4 titanium strip in the 3C field.

Description

Technical Field

[0001] This invention relates to the field of wide TA4 titanium strip preparation technology, specifically to a method for preparing wide TA4 titanium strip. Background Technology

[0002] Titanium is a metallic material with low density, good high-temperature strength, and excellent properties such as superconductivity, hydrogen storage, and shape memory. It is widely used in aerospace, defense, petrochemicals, marine development, superconductivity, nuclear power, medical materials, and civilian applications, with broad application prospects. Among these, TA4 titanium strip, a commonly used material for the back panel of foldable screen mobile phone displays, is experiencing explosive growth in demand in the 3C (computer, communication, and consumer electronics) field, becoming a crucial basic material in this sector. The market demand for wide-width TA4 titanium strip is particularly urgent.

[0003] Currently, the mainstream production method for wide TA4 titanium strip in the industry is a three-pass hot rolling combined with cold rolling, along with atmosphere-protected bell-type furnace annealing. Another similar preparation scheme involves hot rolling and finishing with a hot-roll mill. After hot rolling the slab to 4.0-4.5mm, it undergoes six-roll cold rolling and multi-pass twenty-roll cold rolling, combined with hot-line continuous annealing, pickling, bell-type annealing, and tension leveling processes to produce TA4 strip with a width of 1200-1300mm. This type of process also requires multiple auxiliary processes such as edge trimming and degreasing to complete the overall production process, which involves many steps.

[0004] TA4 titanium strip has a high ferrite content and exhibits significant work hardening during deformation. This material characteristic makes it difficult to roll, and under existing production processes, it is prone to product quality problems such as cold rolling strip breakage, rolling vertical stripes, surface adhesion, and poor strip shape. It is difficult to stably produce high-quality wide TA4 titanium strip with a thickness of 0.5-0.7mm and a width of 1000-1300mm. This is the primary problem that existing technologies have been unable to solve. Existing processes for TA4 strip production typically employ hot rolling mills for finishing. After hot rolling, the slab undergoes six-roll cold rolling and multiple twenty-roll cold rolling processes, combined with hot-line continuous annealing and pickling, bell-type annealing, multiple edge trimming, and tension leveling to complete production. The overall production process involves multiple cold rolling, annealing, and auxiliary processes, which are complex and poorly connected. Hot rolling finishing using hot rolling mills is inefficient and prone to thermal scratches at the ends of the strip. Subsequently, six-roll cold rolling is required. Bell-type annealing suffers from significant differences in heat conduction between the core and edge, and between the strip layers and the surface. This not only results in low production efficiency and high production costs but also leads to poor strip performance uniformity. Current technologies cannot achieve low-cost mass production of wide TA4 titanium strips. Summary of the Invention

[0005] The existing technology has the following problems: wide TA4 titanium strips are difficult to roll and have high costs during production. They are also prone to quality defects such as strip breakage, surface streaks, and poor strip shape. In order to address the above technical problems, the present invention provides a method for preparing wide TA4 titanium strips.

[0006] The technical solution of this invention is: a method for preparing wide TA4 titanium strip, comprising the following steps: S1. Raw material batching and ingot smelting: By mass percentage, 0.55-0.79% titanium dioxide, 0.1-0.35% iron, and the remainder sponge titanium are thoroughly mixed and pressed to obtain an electrode block; the sponge titanium is Grade 1 sponge titanium according to national standard (GB / T 2524-2021); the iron is pure iron nails; and the electrode block is prepared with a density of 3.5 g / cm³ using an 8000-ton hydraulic press. 3 The electrode block is placed in a vacuum arc furnace for melting to obtain TA4 pure titanium ingot; the composition and content of the TA4 pure titanium ingot are O≤0.400%, Fe≤0.500%, N≤0.050%, H≤0.010%, C≤0.080%, with the balance being Ti; the iron element raw material is iron nail; S2. Ingot processing and slab forging finishing: The oxide scale on the surface of the TA4 pure titanium ingot described in S1 is removed by a CNC lathe. The ingot is then heated in a resistance furnace to make the ingot structure a high-temperature structure. It is pressed into a 210×1040×L slab on a 4500-ton high-speed forging hydraulic press. The oxide scale on the surface of the slab is removed by a CNC milling machine. Then, the micro-cracks on the surface of the slab are polished by a grinding machine, and the edges and corners along the length of the slab are chamfered to obtain a finely finished slab. S3. Hot rolling and hot wire annealing and pickling of slabs: The finished slab described in S2 is heated for 240-280 min at a temperature of 900-920 ℃. It is then subjected to 5 passes of rough rolling with a single-pass deformation of 25-40%. Next, it undergoes 7 passes of finish rolling on a continuous rolling mill at an initial temperature of 820-850 ℃ and a single-pass deformation of 15-30%, yielding a black coil with a thickness of 3.0-3.5 mm. The black coil is then subjected to annealing, shot blasting, and pickling, with the annealing temperature controlled at 730-780 ℃ and the processing stroke speed at 10-12 m / min, resulting in a hot-rolled pickled white coil with a thickness of 2.8-3.5 mm. S4, First Cold Rolling Pass: The hot-rolled pickled white coil described in S3 is trimmed, with a trimming amount of 10-20mm on each side. The trimmed hot-rolled pickled white coil is then placed in a 1450 Sendewei 20-roll cold rolling mill for the first cold rolling pass to obtain a first cold-rolled titanium strip with a thickness of 1.2-1.5mm. S5, Pretreatment and Second Cold Rolling: The first cold-rolled titanium strip obtained in S4 is degreased and subjected to intermediate continuous bright annealing to obtain intermediate annealed titanium strip. The intermediate annealed titanium strip is then subjected to shot blasting and pickling to obtain pretreated titanium strip. The pretreated titanium strip is then directly placed in a 20-roll cold rolling mill for the second rolling pass without additional edge trimming to obtain a second cold-rolled titanium strip with a thickness of 0.5-0.7 mm. S6. Final Processing: The second cold-rolled titanium strip S5 is degreased and subjected to continuous bright annealing. After annealing and recrystallization, an annealed titanium strip is obtained. The annealed titanium strip is then subjected to tension leveling and edge trimming to obtain a cold-rolled bright surface wide TA4 titanium strip.

[0007] Note: Using first-grade sponge titanium as raw material and strictly controlling the chemical composition of the ingot, the work hardening characteristics of TA4 titanium strip are alleviated from the source, reducing the difficulty of subsequent rolling. The equipment used in the preparation method of this invention are all conventional special equipment for titanium strip production, without the need for additional or modified equipment. The process route is simple and the connection between each process is smooth, making it easy to industrialize and mass-produce. It can well meet the market demand for wide TA4 titanium strip in the 3C industry.

[0008] Furthermore, in S4, the total deformation during the first cold rolling stroke is controlled to be 40-66%, the deformation per pass is 8-12%, the rolling speed is 50-150 m / min, and the rolling force is 3000-9000 KN.

[0009] Note: This set of rolling parameters is precisely matched to the work hardening characteristics of TA4 titanium strip, avoiding excessive rolling resistance and stress concentration in the titanium strip caused by unreasonable deformation, rolling force or speed. This effectively reduces the risk of strip breakage during cold rolling, while ensuring the uniformity of titanium strip thickness in the first rolling pass, laying a stable billet foundation for the subsequent second rolling pass and improving the overall controllability of the cold rolling process.

[0010] Furthermore, in the second cold rolling stroke of S5, the total deformation is controlled at 50-60%, the deformation per pass is 8-12%, the rolling speed is 50-150 m / min, and the rolling force is 3000-9000 KN.

[0011] Note: This rolling parameter is designed for the microstructure of titanium strip after intermediate annealing and shot blasting and pickling. The uniform deformation per pass can avoid defects such as cracking and wrinkling of titanium strip during cold rolling. Precise rolling force and speed control ensure the dimensional accuracy of titanium strip when finally rolled to the target thickness of 0.5-0.7mm. Moreover, this parameter does not require additional edge trimming, reducing material loss and further improving the yield.

[0012] Furthermore, the intermediate continuous bright annealing process described in S5 is as follows: after the first cold-rolled titanium strip obtained in S4 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for intermediate annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 760-800℃ and the annealing stroke speed is 3m / min to obtain the intermediate annealed titanium strip.

[0013] Explanation: The precise temperature and speed and process parameters of the atmosphere-protected continuous bright annealing furnace can fully and uniformly eliminate the internal stress generated by the first cold rolling stroke, effectively alleviate the work hardening phenomenon of TA4 titanium strip, and reduce the rolling difficulty for the second cold rolling stroke; at the same time, the atmosphere protection can avoid oxidation of titanium strip during annealing, ensure the surface smoothness of titanium strip, and provide a good surface and microstructure foundation for subsequent shot blasting, pickling and cold rolling.

[0014] Further, the shot blasting and pickling treatment method described in S5 is as follows: the intermediate annealed titanium strip is subjected to shot blasting and pickling treatment. During the shot blasting process, the sand feed rate is controlled at 700-1200 kg / min, 1.0-2.0 mm spherical cast steel sand is used, the shot blasting speed is 60-80 m / s, the spray angle is 35-50°, and the shot blasting time is 5-7 min. The pickling process uses an acid solution with a concentration of 18-24 g / L HF solution and a concentration of 160-240 g / L HNO3 solution mixed at a mass ratio of 1:2.5-3.5. The acid solution temperature is controlled at 40-50℃, and the overall stroke speed of shot blasting and pickling is 12-15 m / min to obtain the pretreated titanium strip.

[0015] Explanation: Precisely quantified shot blasting parameters can efficiently remove oxide scale and micro-defects from the titanium strip surface. The acid ratio, temperature, and stroke speed of pickling are adapted to the surface condition of the titanium strip after shot blasting, which can thoroughly clean shot blasting residue and avoid excessive corrosion of the titanium strip by acid. The two work together to effectively eliminate longitudinal rolling vertical stripes, solve the surface adhesion problem, significantly improve the surface quality of titanium strip, and avoid the impact of roll adhesion defects on product quality during subsequent cold rolling.

[0016] Furthermore, the method for continuous bright annealing of the finished product described in S6 is as follows: after degreasing and oil removal of the second cold-rolled titanium strip in S5, it is placed in an atmosphere-protected continuous bright annealing furnace for finished product annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 710-740℃ and the annealing stroke speed is 1.8m / min. After annealing and recrystallization, a uniformly structured annealed titanium strip is obtained.

[0017] Note: The annealing parameters for this finished product are adapted to the work-hardened state of the titanium strip after the second rolling pass. This allows for sufficient recrystallization to refine the grains, ensuring that the titanium strip grain size reaches the required level of 8-10. At the same time, it homogenizes the titanium strip structure, ensuring that the mechanical properties, such as elongation >30% and tensile strength 650-720MPa, are consistently met. The atmosphere-protected continuous bright annealing further enhances the surface brightness of the titanium strip, prevents oxidation of the finished product, and achieves the product requirements for a bright surface after cold rolling.

[0018] Further, the method of tension straightening and finished product edge trimming described in S6 is as follows: the annealed titanium strip is placed on a tension straightening machine for strip shape straightening, the tension of the tension straightening machine process section is controlled at 70-100KN and the tension straightening speed is controlled at 20-60m / min to ensure that the flatness of the titanium strip is ≤3mm / m, and then finished product edge trimming is performed, with 10mm cut off on one side to obtain a cold-rolled bright surface wide TA4 titanium strip. The titanium strip has a grain size of 8-10, an elongation of >30%, and a tensile strength of 650-720MPa.

[0019] Explanation: Precise tension and speed of straightening can effectively correct warping, wavy and other shape deviations of titanium strip during rolling and annealing, ensuring that the flatness of the titanium strip is ≤3mm / m, and solving the technical problem of poor strip shape; the 10mm single-sided trimming of the finished edge can completely remove rolling defects and stress concentration areas on the edge of the titanium strip, improve the performance of the product, and at the same time precisely control the width of the final product to 1200-1300mm, ensuring the dimensional accuracy of the wide titanium strip, and finally obtaining a wide TA4 titanium strip that meets the standards in terms of surface, shape, size and performance.

[0020] Furthermore, the melting vacuum degree in S1 is controlled at 1×10⁻⁶. -3 -5×10 -2 In Pa;S2, the ingot is placed in a resistance furnace and heated to 900-920℃, then held for 60-90 min to completely transform the ingot structure into a β single-phase high-temperature structure.

[0021] Note: 1×10 -3 -5×10 -2 The high vacuum level of Pa in the smelting process can efficiently remove gaseous impurities such as H and N from the furnace, preventing excessive gaseous elements in the ingot and ensuring that the chemical composition of the ingot meets the control requirements such as O≤0.400% and Fe≤0.500%, thus alleviating the work hardening characteristics of TA4 titanium strip from the source. Heating the ingot to 900-920℃ and holding it for 60-90 minutes ensures that the temperature of the ingot core and surface is uniform, allowing the ingot structure to fully transform into a high-temperature single-phase β structure, improving the plasticity of the ingot, reducing the difficulty of subsequent forging, avoiding defects such as cracks, folds, and dents during forging, and ensuring the forming quality of the slab.

[0022] Further, in step S3, the black steel strip is first annealed, and then shot blasted using two shot blasting machines on the same hot-line annealing and pickling line. The method is as follows: During shot blasting, a constant tension roller of 10-30 KN is applied to the black steel strip to prevent warping. The first shot blasting machine uses spherical cast steel sand with a particle size of 1.5-2.0 mm and a Mohs hardness of 7.8-8.2 for coarse blasting. The spray angle for the edge of the titanium strip is 45-50°, the sand feed rate is 900-1200 Kg / min, and the shot blasting speed is 70-80 m / s. The spray angle for the middle of the titanium strip is 35-40°, the sand feed rate is 800-1000 Kg / min, and the shot blasting speed is 70-80 m / s, removing thick oxide scale and stress concentration areas at the edges. The second shot blasting machine uses spherical cast steel sand with a particle size of 1.0-1.5 mm. High-purity spherical zirconia ceramic sand with a Mohs hardness of 6.7-7.0 mm is used in a two-stage hardness gradient shot blasting medium with the spherical cast steel sand from the first shot blasting machine for fine blasting. The spray angles at the edges and center of the titanium belt are both 35-40°. The sand rate in the fine blasting process is 700-900 kg / min, and the shot blasting speed is 60-70 m / s. The fine blasting process removes micro-defects from the surface. The total time for the two shot blasting processes is 5-7 min. After shot blasting, the aforementioned acid pickling treatment is performed.

[0023] Explanation: Applying constant tension roller pressure of 10-30 KN during shot blasting ensures that the wide black steel rolls remain flat throughout the process, preventing warping and deformation. This pre-control of the roll shape from the source provides billets with excellent dimensional stability for subsequent cold rolling. The rough blasting process uses spherical cast steel sand with a Mohs hardness of 7.8-8.2, combined with differentiated spray angles, sand application rates, and shot blasting speeds for the edges and center of the titanium strip. This effectively removes thick oxide scale from the edges, eliminates stress concentration, and avoids excessive impact damage to the titanium strip matrix. The fine blasting process uses high-purity spherical zirconia ceramic sand with a Mohs hardness of 6.7-7.0. Its hardness is higher than that of the rough blasting cast steel sand, allowing for high-precision finishing of the plate surface after rough blasting, accurately removing surface imperfections. This process addresses minute surface defects and, thanks to its high purity and lack of metallic impurities, eliminates the problems of embedded sand, metal contamination, and surface scratches common with conventional cast steel shot. A gradient shot blasting system, using two levels of shot blasting media with different hardness and materials, combined with differentiated process parameters for edges and centers, completely solves the problems of uneven surface treatment, residual oxide scale, and incomplete defect removal inherent in traditional uniform shot blasting. It can eliminate subsequent vertical stripe defects in rolling at their source. This process is strictly compatible with hot-rolled annealing and pickling lines, requiring no equipment modification. While ensuring processing efficiency, it significantly improves the surface finish and microstructure uniformity of hot-rolled billets, reduces stress concentration and strip breakage risks during subsequent cold rolling, and greatly increases the yield of wide TA4 rolls. The overall yield and product quality of titanium belts are improved. The two-stage abrasive uses a combination of medium hardness and large particle size in the first stage and high hardness and small particle size in the second stage. The coarse polishing can peel off the firmly adhered oxide scale on the surface of TA4 titanium belt with sufficient kinetic energy and moderate hardness without severely damaging the soft substrate. The fine polishing relies on the smaller particle size to reduce the impact kinetic energy. Combined with the characteristics of high-purity spherical ceramic sand that is free of sharp edges and metallic impurities, it can refine the micro-defects on the surface without causing scratches or sand embedding. This breaks through the technical contradiction of traditional shot blasting, which is difficult to balance the descaling effect and the surface integrity.

[0024] Furthermore, the degreasing treatments described in S5 and S6 are both spray degreasing. After degreasing, the surface residual degreasing agent is removed by water washing, and then the surface is dried before being transferred to an annealing furnace for continuous bright annealing.

[0025] Explanation: Spray degreasing can achieve uniform and efficient cleaning of rolling oil stains on the surface of titanium strip, with no dead corners and better degreasing effect; the subsequent water washing treatment can thoroughly remove residual degreasing agent from the surface of titanium strip, avoiding carbonization of degreasing agent during annealing, which would affect the surface quality and annealed structure of titanium strip; the drying treatment can ensure that the surface of titanium strip is dry, preventing oxidation spots or uneven structure caused by water on the surface during annealing, providing a clean and dry surface base for atmosphere-protected continuous bright annealing, and ensuring the surface smoothness and uniform structure of titanium strip after annealing.

[0026] The beneficial effects of this invention are: (1) This invention replaces the traditional hot rolling mill with a 7-pass continuous rolling mill to complete hot rolling and finishing. With precise control of heating and rolling deformation parameters, it reduces the problem of hot scratches at the head and tail of titanium strip and narrow gaps at the edges, thus improving the yield. It simplifies the traditional three-pass cold rolling to two passes, eliminating one six-roll cold rolling, one twenty-roll cold rolling and one edge trimming process, which greatly shortens the production process and reduces processing losses. It replaces the traditional bell-type furnace annealing with atmosphere-protected continuous bright annealing, which solves the problems of large heat conduction differences, poor uniformity of titanium strip structure and properties and low production efficiency caused by bell-type furnace annealing. At the same time, it replaces the traditional air annealing and shot blasting pickling with a combination of continuous bright annealing and shot blasting pickling with precise quantitative parameters, which effectively eliminates longitudinal rolling vertical stripes, solves the surface adhesion problem, and improves the surface quality of titanium strip.

[0027] (2) The present invention is adapted to a 20-roll cold rolling equipment and precisely controls the rolling parameters in the cold rolling stage. No additional edge trimming is required in the second rolling cold rolling. In the final processing stage, the plate shape is corrected by precisely controlling the tension leveling parameters, which effectively avoids quality defects such as cold rolling strip breakage and poor plate shape. The synergistic optimization and precise parameter control of each process link finally realizes the stable preparation of cold-rolled bright surface wide TA4 titanium strip. Compared with the existing process, the production process of this method is simpler, the yield is higher, and the processing cost is lower. The prepared product also has excellent surface quality and uniform microstructure properties. Moreover, the mechanical indicators such as grain size, elongation, and tensile strength all meet the requirements for use. It successfully solves the technical problem that it is difficult to stably, cost-effectively, and mass-produce wide TA4 titanium strip in the existing technology. Attached Figure Description

[0028] Figure 1 This is a metallographic diagram of the head section of the cold-rolled bright surface wide TA4 titanium strip in Embodiment 1 of the present invention; Figure 2 This is a metallographic diagram of the middle section of the cold-rolled bright surface wide TA4 titanium strip in Embodiment 1 of the present invention. Detailed Implementation

[0029] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0030] Example 1: A method for preparing a wide TA4 titanium strip includes the following steps: S1. Raw material batching and ingot smelting: By mass percentage, 0.67% titanium dioxide, 0.29% iron, and the remainder sponge titanium were thoroughly mixed and pressed to obtain an electrode block. The sponge titanium was Grade 1 sponge titanium according to national standard (GB / T 2524-2021). The iron was pure iron nails. The electrode block was prepared using an 8000-ton hydraulic press with a density of 3.5 g / cm³.3 The electrode block was placed in a vacuum arc remelting furnace for melting to obtain a TA4 pure titanium ingot. The composition and content of the TA4 pure titanium ingot were: O: 0.320%, Fe: 0.410%, N: 0.030%, H: 0.008%, C: 0.050%, with the balance being Ti. The melting vacuum degree was controlled at 1.5 × 10⁻⁶. -3 Pa; S2. Ingot processing and slab forging finishing: The oxide scale on the surface of the TA4 pure titanium ingot described in S1 was removed by a CNC lathe. The ingot was then heated to 910°C in a resistance furnace and held for 75 minutes to make the ingot structure a high-temperature structure. It was then pressed into a 210×1040×L slab on a 4500-ton high-speed forging hydraulic press. The oxide scale on the surface of the slab was removed by a CNC milling machine. The micro-cracks on the surface of the slab were then polished by a grinding machine, and the edges and corners along the length of the slab were chamfered to obtain a finely finished slab. S3. Hot rolling and hot wire annealing and pickling of slabs: The precision-finished slab described in S2 is heated for 260 min at a temperature of 910 ℃. It is then subjected to 5 passes of rough rolling with a single pass deformation of 30%. Finally, it is subjected to 7 passes of finish rolling on a continuous rolling mill with a starting temperature of 835 ℃ and a single pass deformation of 20%, resulting in a black coil with a thickness of 3.2 mm. The black coil is then subjected to annealing, shot blasting, and pickling, with the annealing temperature controlled at 750 ℃ ​​and the processing stroke speed at 11 m / min, resulting in a hot-rolled pickled white coil with a thickness of 3.1 mm. S4, First Cold Rolling Pass: The hot-rolled pickled white coil described in S3 is trimmed with a single-sided trimming amount of 15mm. The trimmed hot-rolled pickled white coil is then placed in a 1450 Sendewei 20-roll cold rolling mill for rolling. The total rolling deformation is controlled at 58.06%, the deformation per pass is 10%, the rolling speed is 100m / min, and the rolling force is 6000KN, to obtain a first cold-rolled titanium strip with a thickness of 1.3mm. S5, Pretreatment and Second Cold Rolling: The first cold-rolled titanium strip obtained in S4 is degreased and subjected to intermediate continuous bright annealing to obtain an intermediate annealed titanium strip. The intermediate annealed titanium strip is then subjected to shot blasting and pickling to obtain a pretreated titanium strip. The pretreated titanium strip is then directly placed in a 20-roll cold rolling mill for rolling without additional edge trimming. The total rolling deformation is controlled at 55%, the deformation per pass is 10%, the rolling speed is 100 m / min, and the rolling force is 6000 KN to obtain a second cold-rolled titanium strip with a thickness of 0.6 mm. The intermediate continuous bright annealing process is as follows: after the first cold-rolled titanium strip obtained in S4 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for intermediate annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 780℃ and the annealing stroke speed is 3m / min to obtain the intermediate annealed titanium strip. The shot blasting and pickling treatment method is as follows: the intermediate annealed titanium strip is subjected to shot blasting and pickling treatment. During the shot blasting process, the sand feed rate is controlled at 925 kg / min, 1.5 mm spherical cast steel sand is used, the shot blasting speed is 70 m / s, the spray angle is 43°, and the shot blasting time is 6 min. The pickling process uses an acid solution with a concentration of 21 g / L HF solution and a concentration of 200 g / L HNO3 solution mixed at a mass ratio of 1:3. The acid solution temperature is controlled at 45°C, and the overall stroke speed of shot blasting and pickling is 13 m / min, to obtain the pretreated titanium strip. S6. Final Processing: The second cold-rolled titanium strip of S5 is degreased and subjected to continuous bright annealing. After annealing and recrystallization, an annealed titanium strip is obtained. The annealed titanium strip is then subjected to tension leveling and edge trimming to obtain a wide TA4 cold-rolled bright surface titanium strip. The method of continuous bright annealing is as follows: after degreasing and oil removal, the second cold-rolled titanium strip of S5 is placed in an atmosphere-protected continuous bright annealing furnace for annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 725℃ and the annealing stroke speed is 1.8m / min. After annealing and recrystallization, an annealed titanium strip with uniform structure is obtained. The method for tension straightening and finished product edge trimming is as follows: the annealed titanium strip is placed on a tension straightening machine for strip shape straightening. The tension of the tension straightening machine process section is controlled at 85 KN and the tension straightening speed is 40m / min to ensure that the unevenness of the titanium strip is less than 3mm / m. Then, finished product edge trimming is performed, with 10mm cut off on one side to obtain a cold-rolled bright surface wide TA4 titanium strip. The degreasing treatment is all spray degreasing. After degreasing, the surface residual degreasing agent is removed by water washing, and then dried before being transferred to an annealing furnace for continuous bright annealing treatment.

[0031] Example 2: This example is basically the same as Example 1, except that in S3, the black strip is first annealed, and then shot blasted by two shot blasting machines on the same hot-line annealing and pickling line. The method is as follows: During the shot blasting process, a constant tension roller of 20 KN is applied to the black strip to prevent warping of the titanium strip; the first shot blasting machine uses spherical cast steel sand with a particle size of 1.7-1.9 mm and a Mohs hardness of 7.9 for coarse blasting. The spray angle for the edge of the titanium strip is 48°, the sand feed rate is 1000 Kg / min, and the shot blasting speed is 70 m / s. The spray angle for the middle of the titanium strip is 37°, the sand feed rate is 900 Kg / min, and the shot blasting speed is 75 m / s. The shot blasting machine removes thick oxide scale and stress concentration areas at the edges. The second shot blasting machine uses high-purity spherical zirconia ceramic sand with a particle size of 1.2-1.3mm and a Mohs hardness of 6.8. This sand, along with the spherical cast steel sand from the first shot blasting machine, forms a two-stage hardness gradient shot blasting medium for fine blasting. The spray angles at the edges and center of the titanium belt are both 38°. The sand flow rate during the fine blasting process is 800 kg / min, and the shot blasting speed is 65 m / s. This process removes micro-defects from the surface. The total time for both shot blasting processes is 6 minutes. After shot blasting, the aforementioned pickling treatment is performed.

[0032] Example 3: This example is basically the same as Example 1, except that in S3, the black strip is first annealed, and then shot blasted by two shot blasting machines on the same hot-line annealing and pickling line. The method is as follows: During the shot blasting process, a constant tension roller of 10 KN is applied to the black strip to prevent warping of the titanium strip; the first shot blasting machine uses spherical cast steel sand with a particle size of 1.5-1.8 mm and a Mohs hardness of 7.8 for coarse blasting. The spray angle for the edge of the titanium strip is 45°, the sand feed rate is 900 Kg / min, and the shot blasting speed is 70 m / s. The spray angle for the middle of the titanium strip is 35°, the sand feed rate is 800 Kg / min, and the shot blasting speed is 70 m / s. The shot blasting machine removes thick oxide scale and stress concentration areas at the edges. The second shot blasting machine uses high-purity spherical zirconia ceramic sand with a particle size of 1.0-1.2mm and a Mohs hardness of 6.7. This forms a two-stage hardness gradient shot blasting medium with the spherical cast steel sand from the first shot blasting machine for fine blasting. The spray angles at the edges and center of the titanium belt are both 35°. The sand flow rate during the fine blasting process is 700Kg / min, and the shot blasting speed is 60 m / s. This process removes micro-defects from the surface. The total time for both shot blasting processes is 5 min. After shot blasting, the pickling treatment is performed.

[0033] Example 4: This example is basically the same as Example 1, except that in S3, the black strip is first annealed, and then shot blasted by two shot blasting machines on the same hot-line annealing and pickling line. The method is as follows: During the shot blasting process, a constant tension roller of 30 KN is applied to the black strip to prevent warping of the titanium strip; the first shot blasting machine uses spherical cast steel sand with a particle size of 1.8-2.0 mm and a Mohs hardness of 8.2 for coarse blasting. The spray angle for the edge of the titanium strip is 50°, the sand feed rate is 1200 Kg / min, and the shot blasting speed is 80 m / s. The spray angle for the middle of the titanium strip is 40°, the sand feed rate is 1000 Kg / min, and the shot blasting speed is 80 m / s to remove thick oxide scale and stress concentration areas at the edges; the second shot blasting machine uses a particle size of 1.3-1.5 mm. High-purity spherical zirconia ceramic sand with a Mohs hardness of 7.0 mm is used in a two-stage hardness gradient shot blasting medium with the spherical cast steel sand from the first shot blasting machine for fine blasting. The spray angles at the edges and center of the titanium belt are both 40°. The sand flow rate in the fine blasting process is 900 kg / min, the shot blasting speed is 70 m / s, and the surface is free of micro-defects. The total shot blasting time for the two processes is 7 min. After shot blasting, the aforementioned acid pickling treatment is performed.

[0034] Example 5: This example is basically the same as Example 1, except that, by mass percentage, 0.55% titanium dioxide, 0.1% iron element raw material, and the balance sponge titanium are thoroughly mixed and pressed to obtain an electrode block; the sponge titanium is Grade 1 sponge titanium according to national standard (GB / T 2524-2021); the iron element raw material is pure iron block; S3, hot rolling of slab and hot wire annealing and pickling: The precision-finished slab described in S2 is heated for 240 min at a temperature of 900 ℃. It is then subjected to 5 passes of rough rolling with a single pass deformation of 25%. Next, it is subjected to 7 passes of finish rolling on a continuous rolling mill with a starting temperature of 820 ℃ and a single pass deformation of 15%, resulting in a black coil with a thickness of 3.0 mm. The black coil is then subjected to annealing, shot blasting, and pickling treatments, with the annealing temperature controlled at 730 ℃ and the processing stroke speed at 10 m / min, to obtain a hot-rolled pickled white coil with a thickness of 2.8 mm. S4, First Cold Rolling Pass: The hot-rolled pickled white coil described in S3 is trimmed with a single-sided trimming amount of 10mm. The trimmed hot-rolled pickled white coil is then placed in a 20-roll cold rolling mill for the first cold rolling pass to obtain a first cold-rolled titanium strip with a thickness of 1.2mm. S5, Pretreatment and Second Cold Rolling: The first cold-rolled titanium strip obtained in S4 is degreased and subjected to intermediate continuous bright annealing to obtain an intermediate annealed titanium strip. The intermediate annealed titanium strip is then subjected to shot blasting and pickling to obtain a pretreated titanium strip. The pretreated titanium strip is then placed in a 20-roll cold rolling mill for a second cold rolling pass to obtain a second cold-rolled titanium strip with a thickness of 0.5 mm. S6. Final Processing: The second cold-rolled titanium strip S5 is degreased and subjected to continuous bright annealing. After annealing and recrystallization, an annealed titanium strip is obtained. The annealed titanium strip is then subjected to tension leveling and edge trimming to obtain a cold-rolled bright surface wide TA4 titanium strip.

[0035] Example 6: This example is basically the same as Example 1, except that, by mass percentage, 0.79% titanium dioxide, 0.35% iron element raw material, and the balance sponge titanium are thoroughly mixed and pressed to obtain an electrode block; the sponge titanium is Grade 1 sponge titanium according to national standard (GB / T 2524-2021); the iron element raw material is pure iron nail; S3, hot rolling of slab and hot wire annealing and pickling: The precision-finished slab described in S2 is heated for 280 min at a temperature of 920 ℃. It is then subjected to 5 passes of rough rolling with a single pass deformation of 40%. Next, it is subjected to 7 passes of finish rolling on a continuous rolling mill with a starting temperature of 850 ℃ and a single pass deformation of 30%, resulting in a black coil with a thickness of 3.5 mm. The black coil is then subjected to annealing, shot blasting, and pickling treatments, with the annealing temperature controlled at 780 ℃ and the processing stroke speed at 12 m / min, to obtain a hot-rolled pickled white coil with a thickness of 3.5 mm. S4, First Cold Rolling Pass: The hot-rolled pickled white coil described in S3 is trimmed with a single-sided trimming amount of 20mm. The trimmed hot-rolled pickled white coil is then placed in a 20-roll cold rolling mill for the first cold rolling pass to obtain a first cold-rolled titanium strip with a thickness of 1.5mm. S5, Pretreatment and Second Cold Rolling: The first cold-rolled titanium strip obtained in S4 is degreased and subjected to intermediate continuous bright annealing to obtain intermediate annealed titanium strip. The intermediate annealed titanium strip is then subjected to shot blasting and pickling to obtain pretreated titanium strip. The pretreated titanium strip is then placed in a 20-roll cold rolling mill for a second cold rolling pass to obtain a second cold-rolled titanium strip with a thickness of 0.7 mm. S6. Final Processing: The second cold-rolled titanium strip S5 is degreased and subjected to continuous bright annealing. After annealing and recrystallization, an annealed titanium strip is obtained. The annealed titanium strip is then subjected to tension leveling and edge trimming to obtain a cold-rolled bright surface wide TA4 titanium strip.

[0036] Example 7: This example is basically the same as Example 1, except that in S4, the total deformation of the first cold rolling is controlled to be 40%, the deformation per pass is 8%, the rolling speed is 50m / min, and the rolling force is 3000KN.

[0037] Example 8: This example is basically the same as Example 1, except that in S4, the total deformation of the first cold rolling is controlled to be 66%, the deformation per pass is 12%, the rolling speed is 150m / min, and the rolling force is 9000KN.

[0038] Example 9: This example is basically the same as Example 1, except that in S5, the total deformation of the rolling process in the second cold rolling stroke is controlled at 50%, the deformation per pass is 8%, the rolling speed is 50m / min, and the rolling force is 3000KN. The intermediate continuous bright annealing process is as follows: after the first cold-rolled titanium strip obtained in S4 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for intermediate annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 760℃ and the annealing stroke speed is 3m / min to obtain the intermediate annealed titanium strip. The shot blasting and pickling treatment method is as follows: the intermediate annealed titanium strip is subjected to shot blasting and pickling treatment. During the shot blasting process, the sand feed rate is controlled at 700 kg / min, 1.0 mm spherical cast steel sand is used, the shot blasting speed is 60 m / s, the spray angle is 35°, and the shot blasting time is 5 min. The pickling process uses an acid solution with a concentration of 18 g / L HF solution and a concentration of 160 g / L HNO3 solution mixed at a mass ratio of 1:2.5. The acid solution temperature is controlled at 40°C, and the overall stroke speed of shot blasting and pickling is 12 m / min to obtain the pretreated titanium strip.

[0039] Example 10: This example is basically the same as Example 1, except that in S5, during the second cold rolling process, the total rolling deformation is controlled at 60%, the deformation per pass is controlled at 12%, the rolling speed is controlled at 150m / min, and the rolling force is controlled at 9000KN. The intermediate continuous bright annealing process is as follows: after the first cold-rolled titanium strip obtained in S4 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for intermediate annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 800℃ and the annealing stroke speed is 3m / min to obtain the intermediate annealed titanium strip. The shot blasting and pickling treatment method is as follows: the intermediate annealed titanium strip is subjected to shot blasting and pickling treatment. During the shot blasting process, the sand feed rate is controlled at 1200 kg / min, 2.0 mm spherical cast steel sand is used, the shot blasting speed is 80 m / s, the spray angle is 50°, and the shot blasting time is 7 min. The pickling process uses an acid solution with a concentration of 24 g / L HF solution and a concentration of 240 g / L HNO3 solution mixed at a mass ratio of 1:3.5. The acid solution temperature is controlled at 50°C, and the overall stroke speed of shot blasting and pickling is 15 m / min to obtain the pretreated titanium strip.

[0040] Example 11: This example is basically the same as Example 1, except that the method of continuous bright annealing of the finished product in S6 is as follows: after the second cold-rolled titanium strip in S5 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for finished product annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 710℃ and the annealing stroke speed is 1.8m / min. After annealing and recrystallization, the annealed titanium strip is obtained. The method of tension straightening and finished product edge trimming is as follows: the annealed titanium strip is placed on a tension straightening machine for plate shape straightening, the tension of the tension straightening machine process section is controlled at 70KN and the tension straightening speed is 20m / min, and then finished product edge trimming is performed, with 10mm cut off on one side to obtain cold-rolled bright surface wide TA4 titanium strip.

[0041] Example 12: This example is basically the same as Example 1, except that the method of continuous bright annealing of the finished product in S6 is as follows: after the second cold-rolled titanium strip in S5 is degreased and deoiled, it is placed in an atmosphere-protected continuous bright annealing furnace for finished product annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 740℃ and the annealing stroke speed is 1.8m / min. After annealing and recrystallization, the annealed titanium strip is obtained. The method of tension straightening and finished product edge trimming is as follows: the annealed titanium strip is placed on a tension straightening machine for strip shape straightening, the tension of the tension straightening machine process section is controlled at 100KN and the tension straightening speed is 60m / min, and then finished product edge trimming is performed, with 10mm cut off on one side to obtain cold-rolled bright surface wide TA4 titanium strip.

[0042] Example 13: This example is basically the same as Example 1, except that the melting vacuum degree is controlled at 1×10 in S1. -3 In Pa;S2, the ingot is placed in a resistance furnace and heated to 900℃, then held for 60 min to make the ingot structure a high-temperature structure.

[0043] Example 14: This example is basically the same as Example 1, except that the melting vacuum degree is controlled at 5×10 in S1. -2 In Pa;S2, the ingot is placed in a resistance furnace and heated to 920°C, then held for 90 min to make the ingot structure a high-temperature structure.

[0044] Comparative Example 1: Referring to Example 1, the difference is that the shot blasting process in S3 is a single-stage process, using only one shot blasting machine, and using 1.5mm spherical cast steel sand with a Mohs hardness of 7.5. The spray angle is uniformly controlled at 40°, the sand feed rate is 900Kg / min, the shot blasting speed is 75m / s, and the shot blasting time is 6min; the remaining steps and parameters are the same as in Example 1.

[0045] Comparative Example 2: Referring to Example 1, the difference is that the total deformation of the first cold rolling pass in S4 is 70%, with 14% per pass, and the total deformation of the second cold rolling pass in S5 is 70%, with 14% per pass; the intermediate continuous bright annealing treatment in S5 is omitted; the remaining steps and parameters are the same as in Example 1.

[0046] Comparative Example 3: Referring to Example 1, the difference is that the shot blasting medium in S5 is replaced with ordinary alumina ceramic sand containing 0.5% Fe2O3 impurities and with a particle size of 1.5 mm; the intermediate continuous bright annealing temperature in S5 is 650°C and the stroke speed is 3 m / min; the remaining steps and parameters are the same as in Example 1.

[0047] To investigate the properties of the wide TA4 titanium strips in the above examples and control examples, the main materials were determined according to the experimental formulation, and samples were obtained for testing. Grain size determination: According to GB / T 6394-2017, the intercept method was used, with two parallel samples tested per specimen, and the two values ​​(grades) were recorded. Transverse mechanical property testing: According to GB / T 228.1-2021, room temperature testing was conducted, with two parallel samples per batch. The two values ​​of Rm transverse (MPa), Rp0.2 transverse (MPa), and A transverse (%) were recorded, and the mean was calculated. The specific investigation is as follows: Table 1 Performance test results of wide TA4 titanium strip samples from Examples 1-14 and Comparative Examples 1-3

[0048] 1. Investigating the influence of heat treatment process parameters on the properties of wide TA4 titanium strip: Comparing Examples 1, 2, 3, and 4 with Control Example 1, it can be seen that Example 4 has the best overall performance, followed by Example 1, Example 2 has slightly inferior overall performance compared to Example 1, Example 3 has the next best overall performance, and Control Example 1 has the worst overall performance. Changing the heat treatment process parameters and the shot blasting process, medium parameters, and operating parameters will have a certain impact on the performance of the prepared wide TA4 titanium strip samples. The two-stage gradient shot blasting process is far superior to the single-stage shot blasting process. Adjusting the shot blasting parameters at each stage in the two-stage gradient shot blasting process will also lead to differences in sample performance, while the performance of samples prepared using a single-stage shot blasting process other than this method will show a significant decrease. Figure 1 , 2 It can be seen that the metallographic structure of the cold-rolled bright surface wide TA4 titanium strip prepared in Example 1 has excellent uniformity in the head and middle of the roll.

[0049] 2. Investigating the influence of hot rolling and cold rolling process parameters on the properties of wide TA4 titanium strip: Comparing Examples 1, 5, 6, 7, and 8, Example 8 exhibits the best overall performance, followed by Example 1. Example 6's overall performance is slightly inferior to Example 1, and Example 5's overall performance is even worse. Example 7 has the worst overall performance in this group. This indicates that changing the heating and rolling parameters of hot rolling, as well as the deformation amount, rolling speed, and rolling force of the first cold rolling pass, will have a certain impact on the performance of the prepared wide TA4 titanium strip samples. Fine-tuning the hot rolling parameters and reasonably increasing the cold rolling deformation amount can optimize the sample performance, while a low cold rolling deformation amount will lead to a decrease in sample performance.

[0050] 3. Investigate the influence of the second-stage cold rolling and intermediate processing parameters on the properties of wide TA4 titanium strip: Comparing Examples 1, 9, and 10, it can be seen that Example 1 has the best overall performance, followed by Example 10, while Example 9 has the worst overall performance in the group. This shows that changing the deformation amount, rolling speed, rolling force parameters of the second rolling cold rolling, as well as the process parameters of intermediate continuous bright annealing, shot blasting, and pickling, will have a certain impact on the performance of the prepared wide TA4 titanium strip samples. Increasing the deformation amount of the second rolling cold rolling within a reasonable range and matching the corresponding intermediate processing parameters can bring the sample performance close to the optimal level, while reducing the relevant parameters will lead to a decrease in sample performance.

[0051] 4. Investigate the effects of finished product processing and smelting / forging process parameters on the properties of wide TA4 titanium strip: Comparing Examples 1, 11, 12, 13, and 14 with Control Examples 2 and 3, it can be seen that Example 13 has the best overall performance, followed by Example 1, Example 14 has slightly worse overall performance than Example 1, Example 12 has the next worst overall performance, Example 11 has the worst overall performance among the examples, Control Example 3 has a worse overall performance than all examples, and Control Example 2 has the worst overall performance among all groups. It can be seen that changing the process parameters of continuous bright annealing, edge straightening and trimming of the finished product, as well as the parameters of melting vacuum degree and ingot heating and forging, will have a certain impact on the performance of the prepared wide TA4 titanium strip samples. Fine-tuning of melting and forging parameters can bring the sample performance close to the optimal level, while deviations in finished product processing parameters will lead to a decrease in sample performance. Control Examples 2 and 3, which were prepared using cold rolling and intermediate processing processes other than this method, have performance far lower than all examples.

Claims

1. A method for preparing a wide TA4 titanium strip, characterized in that, Includes the following steps: S1. Raw material batching and ingot smelting: By mass percentage, 0.55-0.79% of titanium dioxide, 0.1-0.35% of iron element raw materials, and the balance of sponge titanium are thoroughly mixed and pressed to obtain an electrode block. The electrode block is then placed in a vacuum arc furnace for melting to obtain TA4 pure titanium ingot. S2. Ingot processing and slab forging finishing: The oxide scale on the surface of the TA4 pure titanium ingot described in S1 is removed by a CNC lathe. The ingot is placed in a resistance furnace and heated to make the ingot structure a high-temperature structure. It is pressed into a slab on a high-speed forging hydraulic press. The oxide scale on the surface of the slab is removed by a CNC milling machine. Then, the micro-cracks on the surface of the slab are polished by a grinding equipment, and the edges and corners along the length of the slab are chamfered to obtain a finely finished slab. S3. Hot rolling and hot wire annealing and pickling of slabs: The precision-finished slab described in S2 is heated for 240-280 min at a temperature of 900-920 ℃. It is first rough-rolled in 5 passes with a deformation of 25-40% per pass, and then finished in 7 passes using a continuous rolling mill at a temperature of 820-850 ℃ and a deformation of 15-30% per pass, to obtain a black coil with a thickness of 3.0-3.5 mm. The black coil is then subjected to annealing, shot blasting, and pickling, with the annealing temperature controlled at 730-780 ℃ and the processing speed at 10-12 m / min, to obtain a hot-rolled pickled white coil. S4, First Cold Rolling Pass: The hot-rolled pickled white coil described in S3 is trimmed, with a trimming amount of 10-20mm on each side. The trimmed hot-rolled pickled white coil is then placed in a 20-roll cold rolling mill for the first cold rolling pass to obtain a first cold-rolled titanium strip with a thickness of 1.2-1.5mm. S5, Pretreatment and Second Cold Rolling: The first cold-rolled titanium strip obtained in S4 is degreased and subjected to intermediate continuous bright annealing to obtain an intermediate annealed titanium strip. The intermediate annealed titanium strip is then subjected to shot blasting and pickling to obtain a pretreated titanium strip. The pretreated titanium strip is then placed in a 20-roll cold rolling mill for a second cold rolling pass to obtain a second cold-rolled titanium strip with a thickness of 0.5-0.7 mm. S6. Final Processing: The second cold-rolled titanium strip S5 is degreased and subjected to continuous bright annealing. After annealing and recrystallization, an annealed titanium strip is obtained. The annealed titanium strip is then subjected to tension leveling and edge trimming to obtain a wide cold-rolled bright TA4 titanium strip with a width of 1200-1300 mm. In S4, the total deformation during the first cold rolling stroke is controlled to be 40-66%, the deformation per pass is 8-12%, the rolling speed is 50-150 m / min, and the rolling force is 3000-9000 KN. In the second cold rolling stroke of S5, the total deformation is controlled at 50-60%, the deformation per pass is 8-12%, the rolling speed is 50-150 m / min, and the rolling force is 3000-9000 KN. The intermediate continuous bright annealing process described in S5 is as follows: after degreasing the first cold-rolled titanium strip obtained in S4, it is placed in an atmosphere-protected continuous bright annealing furnace for intermediate annealing, and the annealing temperature is controlled at 760-800℃ and the annealing stroke speed is 3m / min to obtain the intermediate annealed titanium strip. After degreasing the second cold-rolled titanium strip S5, it is placed in an atmosphere-protected continuous bright annealing furnace for finished product annealing. The process section of the annealing furnace is 18 meters long, and the annealing temperature is controlled at 710-740℃ and the annealing stroke speed is 1.8m / min. After annealing and recrystallization, annealed titanium strip is obtained.

2. The method for preparing a wide TA4 titanium strip according to claim 1, characterized in that, The shot blasting and pickling treatment method described in S5 is as follows: the intermediate annealed titanium strip is subjected to shot blasting and pickling treatment. During the shot blasting process, the sand feed rate is controlled at 700-1200 kg / min, 1.0-2.0 mm spherical cast steel sand is used, the shot blasting speed is 60-80 m / s, the spray angle is 35-50°, and the shot blasting time is 5-7 min. The pickling process uses an acid solution with a concentration of 18-24 g / L HF solution and a concentration of 160-240 g / L HNO3 solution mixed at a mass ratio of 1:2.5-3.

5. The acid solution temperature is controlled at 40-50℃, and the overall stroke speed of shot blasting and pickling is 12-15 m / min to obtain the pretreated titanium strip.

3. The method for preparing a wide TA4 titanium strip according to claim 1, characterized in that, The method of tension straightening and finished product edge trimming described in S6 is as follows: the annealed titanium strip is placed on a tension straightening machine for plate shape straightening, the tension of the tension straightening machine process section is controlled at 70-100KN and the tension straightening speed is controlled at 20-60m / min, and then finished product edge trimming is performed, with 10mm cut off on one side to obtain cold-rolled bright surface wide TA4 titanium strip.

4. The method for preparing a wide TA4 titanium strip according to claim 1, characterized in that, S1 controls the melting vacuum level to 1×10 -3 -5×10 -2 In Pa;S2, the ingot is placed in a resistance furnace and heated to 900-920℃, then held for 60-90 min to make the ingot structure a high-temperature structure.

5. The method for preparing a wide TA4 titanium strip according to claim 1, characterized in that, In step S3, the black steel strip is first annealed, and then shot blasted using two shot blasting machines on the same hot-line annealing and pickling line. The method is as follows: during shot blasting, a constant tension roller of 10-30 KN is applied to the black steel strip to prevent warping. The first shot blasting machine uses spherical cast steel sand with a particle size of 1.5-2.0 mm for coarse blasting. The spray angle for the edges of the titanium strip is 45-50°, the sand flow rate is 900-1200 Kg / min, and the shot blasting speed is 70-80 m / s. The spray angle for the middle of the titanium strip is 35-40°, the sand flow rate is 800-1000 Kg / min, and the shot blasting speed is 70-80 m / s, removing thick oxide scale and stress concentration areas at the edges. The second shot blasting machine uses spherical zirconia ceramic sand with a particle size of 1.0-1.5 mm for fine blasting. The spray angle for both the edges and the middle of the titanium strip is 35-40°. °, the sand content in the fine polishing process is 700-900 Kg / min, the shot blasting speed is 60-70 m / s, and the fine polishing process removes micro-defects on the surface; the total time for two shot blasting processes is 5-7 min, and the pickling treatment is performed after shot blasting.

6. The method for preparing a wide TA4 titanium strip according to claim 1, characterized in that, The degreasing processes described in S5 and S6 are both spray degreasing. After degreasing, the surface residual degreasing agent is removed by water washing, and then the surface is dried before being transferred to an annealing furnace for continuous bright annealing.

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