A method for preparing a large single-weight, large-thickness, super-wide high-toughness titanium alloy plate

Abstract

The present application belongs to the technical field of titanium alloy processing, and discloses a preparation method of large single weight, large thickness and super wide high-toughness titanium alloy plate, which is suitable for preparing titanium alloy plate with thickness of 100-200 mm, width of 2000-3000 mm and length of 4000-10000 mm. The method adopts large-size ingot obtained by three-time VAR vacuum self-consumption arc melting to prepare the plate, obtains a formed alloy plate blank through multi-fire forging, and then obtains the finished plate through reversing rolling, and finally obtains the large single weight, large thickness and super wide high-toughness finished plate with excellent plate shape, structure and performance through heat treatment and straightening.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of titanium alloy processing, and particularly relates to a preparation method of large-weight, large-thickness and ultra-wide high-toughness titanium alloy plate. BACKGROUND

[0002] Titanium alloy has been developed since the 1950s, and is an important structural metal, which has the characteristics of low density, high strength, high corrosion resistance and high toughness, and can be widely applied in the fields of aviation, aerospace and navigation. With the continuous development of titanium industry, the consumption and specifications of titanium alloy products are also increasing. Especially in the field of deep-sea equipment, the demand for titanium alloy plates is increasing. Titanium alloy has high strength, low density and excellent corrosion resistance, which makes it an ideal material for manufacturing deep-sea equipment pressure hulls. Titanium alloy plates also have application potential for aircraft carriers' flight decks, which can withstand the impact of aircraft take-off and landing and the corrosion of marine environment due to their high strength and corrosion resistance. Therefore, the development of large-weight and large-specification titanium alloy plates is the vision of titanium alloy design and development in the field of deep-sea equipment application.

[0003] However, the preparation of large-specification titanium alloy plates is limited by objective factors such as process design and equipment capacity. In addition, titanium alloy has poor thermal conductivity, large deformation resistance, and sensitive microstructure to temperature process parameters, which makes the deformation uniformity of titanium alloy decrease during forging, and defects such as overheating, local coarse grains and bright bands are easily produced in the microstructure, which seriously affects the microstructure uniformity and mechanical properties. In addition, the deformation process parameters such as deformation amount and deformation rate during hot working of titanium alloy will affect the surface quality of the material. Improper process parameter setting will increase the defects such as surface cracks of the material, and increase the difficulty of subsequent hot working or plate surface treatment process. Therefore, it is urgent to develop a reasonable titanium alloy plate preparation method which can improve the microstructure uniformity and ensure that the large-specification high-toughness titanium alloy plate product has a high performance safety margin and mechanical property uniformity. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of large-weight, large-thickness and ultra-wide high-toughness titanium alloy plate, which uses large-specification ingots obtained by three-time VAR vacuum consumable arc melting for plate preparation, and prepares plate blanks through multiple upsetting and drawing and widening, and then obtains finished plates through reversing rolling, and finally obtains finished plates with excellent plate shape, microstructure and performance through heat treatment and straightening. This method can solve the existing technical problems faced by large-specification high-toughness titanium alloy plates during the preparation stage.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows.

[0006] On the one hand, the present application provides a preparation method of large-weight, large-thickness and ultra-wide high-toughness titanium alloy plate, which comprises the following steps:

[0007] S1: mixing the required raw materials of the titanium alloy plate and pressing into several electrode blocks to prepare large-scale ingots by three times of VAR vacuum self-consumption arc melting;

[0008] S2: multi-fire forging of the large-scale ingots obtained in step S1, including high-temperature blooming forging of the ingots, forging below and above the phase transition point, two-phase zone forging and plate blank forming forging, to obtain a formed alloy plate blank;

[0009] S3: plate rolling of the formed alloy plate blank obtained in step S2 to obtain a finished plate;

[0010] S4: heat treatment of the finished plate obtained in step S3, including annealing and straightening.

[0011] Further, the high-temperature blooming forging of the ingots includes placing the large-scale ingots into a resistance heating furnace, first heating to 700-800℃, holding for 2-3h, then heating to a heating temperature of 1100-1150℃, holding coefficient 0.6-0.7, upsetting and upsetting to a square billet with a height-diameter ratio of 1.7-2.0; reheat holding coefficient 0.2-0.3, after discharge, upsetting and elongation forging, total deformation 70-80%, air cooling after forging, to obtain an alloy square billet;

[0012] The forging below and above the phase transition point includes heating the alloy square billet at T β -(20-35)℃, holding coefficient 0.6-0.7, heating to T β +(30-50)℃ after forging, holding coefficient 0.4-0.5, air cooling to room temperature after forging, to obtain an alloy forged blank;

[0013] The two-phase zone forging includes two to three times of heating forging of the alloy forged blank below the phase transition point to improve the uniformity of the structure, the forging heating temperature being T β -(20-30)℃, holding coefficient 0.6-0.7, reheat twice per fire, holding coefficient 0.2-0.3, air cooling after each fire, to obtain an alloy intermediate blank;

[0014] The plate blank forming forging includes heating the alloy intermediate blank at T β -(20-30)℃, holding coefficient 0.6-0.7, reheat holding coefficient 0.2-0.3, to perform the spreading and elongation deformation of the plate blank, to obtain an alloy formed plate blank.

[0015] Further, in step S3, gradient heating is used for plate rolling; first heating to T β-(60-70)℃ for 1-2h, then heated to T β -(20-30)℃, the insulation factor is 1.5-1.8; after the billet is discharged, the billet is transversely spread and rolled with the billet long side as the width direction; after the billet is rolled to the predetermined width, the billet is reheated and insulated for 2-3h, and then the billet is longitudinally rolled to the finished product size.

[0016] Further, in step S4, the plate is annealed at an annealing temperature T β -(20-40)℃, the insulation factor is 2-4, after the billet is discharged, the billet is straightened at high temperature, and then the billet is air cooled to room temperature.

[0017] Further, in step S2, after each upsetting and drawing forging is finished, chamfering is performed, the chamfering reduction is L=(0.1-0.15)×square billet cross-section diagonal length, the billet is ground after the forging, and the depth-width ratio of the billet is less than 1:9 after the grinding.

[0018] Further, in the forging at the phase transition point, the forging above the phase transition point and the forging in the two-phase region, upsetting and drawing deformation is performed after each time the billet is discharged, the billet is reheated and temperature compensated, and then the next upsetting and drawing deformation is performed, and the upsetting and drawing deformation amount is 70%-80% each time.

[0019] Further, in the billet forming forging, the deformation amount of each time of spreading and drawing is 10%-30%, after the billet width is spread to the predetermined value, only drawing is performed on the billet, and the deformation amount of the last two times of drawing is controlled to be 10%-15%.

[0020] Further, in step S3, the billet discharge transfer time is less than 70s. The pass reduction of the transverse rolling is 10-15mm, and the pass reduction of the longitudinal rolling is 7-15mm.

[0021] On the other hand, the application provides a large single weight, large thickness, ultra-wide high-toughness titanium alloy plate, which is prepared by the above preparation method.

[0022] Further, the thickness of the titanium alloy plate is 100-200mm, the width is 2000-3000mm, and the length is 4000-10000mm.

[0023] Compared with the prior art, the application has the following advantages:

[0024] The present application starts from the existing equipment level in the industry, and proceeds with the preparation of the plate from three aspects of ingot smelting, slab forging and finished plate rolling. The ingot is prepared by three times of VAR vacuum consumable arc smelting to improve the uniformity of the ingot composition. The slab forging includes multiple forging stages to fully deform the slab and improve the uniformity of the structure. The plate rolling adopts the reversing rolling method to avoid the adverse effects such as anisotropy of the plate caused by one-way rolling. Finally, the finished heat treatment obtains large single-weight, large-thickness, super-wide-width high-toughness titanium alloy plate with excellent plate type, structure and performance. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the transverse microstructure of the head of the 130mm-thick TA31 alloy plate prepared in Example 1 of the present application;

[0026] Figure 2 is the longitudinal microstructure of the head of the 130mm-thick TA31 alloy plate prepared in Example 1 of the present application;

[0027] Figure 3 is the transverse microstructure of the tail of the 130mm-thick TA31 alloy plate prepared in Example 1 of the present application;

[0028] Figure 4 is the longitudinal microstructure of the tail of the 130mm-thick TA31 alloy plate prepared in Example 1 of the present application;

[0029] Figure 5 is the transverse microstructure of the head of the 160mm-thick TA31 alloy plate prepared in Example 2 of the present application;

[0030] Figure 6 is the longitudinal microstructure of the head of the 160mm-thick TA31 alloy plate prepared in Example 2 of the present application;

[0031] Figure 7 is the transverse microstructure of the tail of the 160mm-thick TA31 alloy plate prepared in Example 2 of the present application;

[0032] Figure 8 is the longitudinal microstructure of the tail of the 160mm-thick TA31 alloy plate prepared in Example 2 of the present application. DETAILED DESCRIPTION

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0034] In the present application, when referring to a numerical interval (i.e., a numerical range), unless otherwise specified, the optional numerical values are considered to be continuous within the numerical interval, and include the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every numerical value between the two numerical endpoints. When a numerical interval refers only to integers within the numerical interval, unless otherwise specified, the two endpoints and every integer between the two endpoints are considered to be directly listed, e.g., t is an integer selected from 1-10 means that t is any one of the integers selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, ranges disclosed herein are to be understood to include any and all sub-ranges subsumed therein.

[0035] In the present application, unless otherwise specified, the temperature parameter allows for both constant temperature processing and for variations within a certain temperature interval. It should be understood that the constant temperature processing allows for fluctuations within the accuracy of the instrument control. Fluctuations within a range of, for example, ±5°C, ±4°C, ±3°C, ±2°C, ±1°C are allowed.

[0036] The present application provides a method for preparing a large single weight, large thickness, and ultra-wide high-toughness titanium alloy plate, comprising the following steps:

[0037] S1: mixing the required raw materials for the titanium alloy plate and pressing them into several electrode blocks, and preparing a large-size ingot through three times of VAR vacuum consumable arc melting;

[0038] S2: performing multi-pass forging on the large-size ingot obtained in step S1, including high-temperature breakdown forging of the ingot, forging below and above the phase transition point, two-phase zone forging, and plate blank forming forging, to obtain a formed alloy plate blank;

[0039] S3: performing plate rolling on the formed alloy plate blank obtained in step S2 to obtain a finished plate;

[0040] S4: performing finished heat treatment on the finished plate obtained in step S3, including annealing and straightening.

[0041] In some embodiments, the present application provides a method for preparing a large single weight, large thickness, and ultra-wide high-toughness titanium alloy plate, comprising the following steps:

[0042] S1: mixing the required raw materials for the alloy and pressing them into several electrode blocks, and preparing a large-size ingot through three times of VAR vacuum consumable arc melting.

[0043] S2: performing multi-pass forging on the large-size ingot obtained in step S1, specifically including the following steps:

[0044] S2.1: high temperature open-die forging of ingot

[0045] The ingot is placed in a resistance heating furnace, first heated to 700-800°C, held for 2-3h, then heated to 1100-1150°C, held for 0.6-0.7, upset and reduced to a square billet with a height to diameter ratio of 1.7-2.0; the heating and holding factor is 0.2-0.3, after the furnace is opened, upset and elongated, the total deformation is 70-80%, large deformation forging can fully break the as-cast grains, and air cooled after forging.

[0046] S2.2: sub-transus forging and super-transus forging

[0047] The alloy square billet is heated at T β -(20-30) °C, held for 0.6-0.7, after the furnace is opened, heated to T β +(30-50) °C, held for 0.4-0.5, air cooled to room temperature after forging. Sub-transus heating forging provides sufficient distortion energy for secondary high temperature forging, and enhances the grain refinement effect of high temperature dynamic recrystallization.

[0048] S2.3: two-phase region forging

[0049] The alloy forging billet is heated at sub-transus for two to three times to improve the degree of microstructure homogenization. The heating temperature for forging is T β -(20-30) °C, held for 0.6-0.7, the furnace is opened twice for each heating, held for 0.2-0.3, air cooled after each heating.

[0050] S2.4: slab forming forging

[0051] The alloy intermediate billet obtained in S2.3 is heated at T β -(20-30) °C, held for 0.6-0.7, the furnace is opened twice for each heating, held for 0.2-0.3, the slab is expanded and elongated.

[0052] S3: finished plate rolling

[0053] The plate rolling adopts gradient heating. First heated to T β -(60-70) °C, held for 1-2h, then heated to T β -(20-30) °C at a rate of 60 °C / h, held for 1.5-1.8; after the furnace is opened, the slab is expanded in the transverse direction with the long side as the width direction; after rolling to the predetermined width, the furnace is opened again and held for 2-3h, then rolled in the longitudinal direction to the finished size.

[0054] S4: finished heat treatment

[0055] The plate is annealed, and the annealing temperature T is β -(20-40)℃, the insulation coefficient is 2-4, after discharging, high temperature is used for straightening, and after straightening, air cooling is carried out to room temperature.

[0056] Further, in the forging process of step S2, the time for transferring the blank from the furnace to the quick forging machine is less than 180s. After each upsetting and drawing forging, chamfering treatment is carried out, the chamfering reduction L is (0-0.15)×the diagonal length of the square blank cross section, after forging, grinding is carried out, and the depth-width ratio after grinding is less than 1:9.

[0057] Further, in the forging at the phase transition point, the forging above the phase transition point and the two-phase region forging, after each time of discharging, upsetting and drawing deformation is carried out, after returning to the furnace for temperature compensation, the next upsetting and drawing deformation is carried out, and the upsetting and drawing deformation amount of each time is 70%-80%.

[0058] Further, in the plate blank forming forging, the deformation amount of each time of spreading and drawing is 10%-30%, after the plate blank width is spread to a predetermined value, only drawing treatment is carried out on the plate blank, and the deformation amount of the last two times of drawing deformation is controlled to be 10%-15%.

[0059] Further, in step S3, the time for transferring the plate blank from the furnace is less than 70s. The pass reduction amount of transverse rolling is 10-15mm, and the pass reduction amount of longitudinal rolling is 7-15mm.

[0060] Further, the above plate preparation method is suitable for preparing a titanium alloy plate with a thickness of 100-200mm, a width of 2000-3000mm and a length of 4000-10000mm.

[0061] For the purpose, technical scheme and advantages of the present application, the present application will be described in detail below in combination with specific examples and the drawings of the specification. The specific examples described herein are only used to explain the present application, and the present application is not limited thereto.

[0062] Example 1: TA31 titanium alloy plate, size 130×2230×8200mm

[0063] The present embodiment provides a method for preparing a TA31 titanium alloy plate, which comprises the following steps:

[0064] S1: high-purity titanium sponge is used as the main Ti element adding raw material, supplemented by Al-Nb intermediate alloy, Al-Mo intermediate alloy, aluminum foil, aluminum particles and zirconium sponge to add other required metal elements, pressed into several electrode blocks, and prepared into a TA31 titanium alloy large-size ingot through three times of VAR vacuum consumable arc melting.

[0065] S2: The large-sized ingot obtained in step S1 is subjected to multiple forging processes, specifically including the following steps:

[0066] S2.1: High-temperature forging of ingots.

[0067] Large-sized ingots are placed in a resistance heating furnace and first heated to 800℃ and held for 2 hours. Then the temperature is raised to 1150℃ with a holding coefficient of 0.6. The ingots are then riveted, upset, and shaped into square billets with a height-to-diameter ratio of 2.0. The billets are then reheated in the furnace with a holding coefficient of 0.2. After being taken out of the furnace, they are upset and drawn forged with a total deformation of 80%. After forging, they are air-cooled to obtain TA31 alloy square billets.

[0068] S2.2: Forging below the phase transformation point and forging above the phase transformation point.

[0069] Heat the TA31 alloy billet to T. β -30℃, heat retention coefficient 0.7, heated to T after forging. β The TA31 alloy forging billet was obtained by air cooling to room temperature after forging at +50℃ with a thermal insulation coefficient of 0.5.

[0070] S2.3: Two-phase zone forging.

[0071] The TA31 alloy forging billet was subjected to three-stage heating forging at its phase transformation point, with a heating temperature of T. β -30℃, heat preservation coefficient 0.7, two reheatings per firing, heat preservation coefficient 0.3, air cooling after each forging, to obtain TA31 alloy intermediate billet.

[0072] S2.4: Slab forming and forging.

[0073] Heat the TA31 alloy intermediate billet to T. β At -30℃, with a thermal insulation coefficient of 0.7 and a reheat thermal insulation coefficient of 0.3, the slab is subjected to widening and elongation deformation, with a widening deformation of 25% and an elongation deformation of 15%, to obtain a shaped alloy slab.

[0074] S3: Rolling of finished sheet metal.

[0075] The formed alloy slab is rolled into sheet metal using gradient heating. First, it is heated to T... β Hold at -60℃ for 1 hour, then heat at a rate of 60℃ / h to T β -30℃, heat preservation coefficient 1.5; after exiting the furnace, the slab is rolled laterally with the long side as the width direction; after rolling to the predetermined width, it is returned to the furnace for heat preservation for 2 hours, and after exiting the furnace, it is rolled longitudinally to the finished size.

[0076] S4: Finished product heat treatment.

[0077] The finished sheet material is annealed at a temperature T. β-25℃, thermal insulation coefficient 3.0, straightened at high temperature after being taken out of the furnace, and then air-cooled to room temperature to obtain TA31 alloy plate with dimensions of 130×2230×8200mm.

[0078] like Figures 1-4 As shown, the microstructure of the TA31 alloy plate with dimensions of 130×2230×8200mm is composed of equiaxed α and β transformation phases, with the primary α phase accounting for about 13% to 16%. The microstructure is uniform at both ends, and no streamlined microstructure is observed in the transverse and longitudinal structures.

[0079] Table 1 shows the mechanical properties of the high-weight, thick, ultra-wide, and high-toughness titanium alloy plates prepared in this embodiment.

[0080] Table 1 Mechanical properties of the sheet material in Example 1

[0081]

[0082] As shown in Table 1, the mechanical properties of the plate show little difference between the beginning and end. The average yield strength and impact energy are 784 MPa and 59.6 J, respectively, with coefficients of variation of 1.91% and 8.01%. The average fracture toughness is 126.4 MPa·m. 1 / 2 This indicates that the alloy plate prepared in this embodiment has a certain safety margin in use, and the low coefficient of variation indicates that the plate has good uniformity of mechanical properties.

[0083] Example 2: TA31 titanium alloy sheet, dimensions: 160×2630×5300mm

[0084] This embodiment provides a method for preparing TA31 titanium alloy sheet, including the following steps:

[0085] S1: High-purity sponge titanium is used as the main raw material for Ti element addition, supplemented with Al-Nb master alloy, Al-Mo master alloy, aluminum foil, aluminum granules and sponge zirconium to add other required metal elements, pressed into several electrode blocks, and prepared into TA31 titanium alloy large-size ingots through three VAR vacuum self-consuming arc melting processes.

[0086] S2: The large-sized ingot obtained in step S1 is subjected to multiple forging processes, specifically including the following steps:

[0087] S2.1: High-temperature forging of ingots.

[0088] The large ingot is put into the resistance heating furnace, firstly heated to 800℃, and kept for 2h, then heated to the heating temperature 1150℃, the holding coefficient is 0.6, the upsetting and upsetting are performed, and the square billet with the height-diameter ratio of 2.0 is obtained; the heating holding coefficient is 0.2, after the furnace is discharged, the upsetting and elongation forging are performed, the total deformation is 80%, the air cooling is performed after the forging, and the TA31 alloy square billet is obtained.

[0089] S2.2: Forging below the phase transition point and forging above the phase transition point.

[0090] The TA31 alloy square billet is heated to T β -30℃, the holding coefficient is 0.7, after the furnace is discharged, the forging is performed, then heated to T β +50℃, the holding coefficient is 0.5, the air cooling is performed to room temperature after the forging, and the TA31 alloy forged blank is obtained.

[0091] S2.3: Two-phase zone forging.

[0092] The TA31 alloy forged blank is heated to T β -30℃ below the phase transition point for two heating times, the heating temperature is T β -30℃, the holding coefficient is 0.7, the furnace is discharged twice for each heating time, the holding coefficient is 0.3, the air cooling is performed after each heating time, and the TA31 alloy intermediate blank is obtained.

[0093] S2.4: Plate blank forming forging.

[0094] The TA31 alloy intermediate blank is heated to T β -30℃, the holding coefficient is 0.7, the furnace is discharged twice for each heating time, the holding coefficient is 0.3, the air cooling is performed after each heating time, and the TA31 alloy intermediate blank is obtained.

[0095] S3: Product plate rolling.

[0096] The plate rolling is performed on the formed alloy plate blank, and gradient heating is adopted in the plate rolling. Firstly, the heating is performed to T β -30℃, the holding coefficient is 1.7; after the furnace is discharged, the plate blank is transversely expanded and rolled with the long side of the plate blank as the width direction; after the rolling to the predetermined width, the furnace is discharged and kept for 2h, and then the longitudinal rolling is performed to the product size.

[0097] S4: Product heat treatment

[0098] The annealing treatment is performed on the product plate, the annealing temperature is T β -25℃, the holding coefficient is 3.0, after the furnace is discharged, the high-temperature straightening is performed, and the air cooling is performed to room temperature after the straightening, so that the TA31 alloy plate with the size of 160*2630*5300 is prepared.

[0099] For example, Figures 5-8As shown, the microstructure of the prepared TA31 alloy plate with the size of 160x2630x5300 consists of equiaxed α and β transformed phase, the content of primary α phase is about 15% to 20%, the microstructure of head and tail part is uniform, and no streamline microstructure morphology is found in the transverse and longitudinal microstructure.

[0100] The mechanical properties of the large single weight, large thickness, super wide width high toughness titanium alloy plate prepared in the present embodiment are shown in Table 2.

[0101] The mechanical properties of the plate of Example 2 are shown in Table 2

[0102]

[0103] As can be seen from the mechanical property test results in Table 2, the mechanical properties of the head and tail part of the plate have small difference, the average yield strength and impact absorption energy are 781 MPa and 56.5 J respectively, the variation coefficients of the two performances are 1.09% and 9.39% respectively, and the average fracture toughness is 127.4 MPa·m 1 / 2 Compared with the 130 mm thick plate of Example 1, the difference is small, indicating that the mechanical property uniformity of the large thickness plate prepared by using the method is good.

[0104] It should be noted that the above described embodiments are only preferred embodiments of the present application. For ordinary skilled in the art, some modifications, improvements and equivalent replacements can be made to the present application without departing from the principles of the present application, and these modifications, improvements and equivalent replacements are also considered to fall within the protection scope of the claims of the present application.

Claims

1. A method for producing a large single unit, large thickness, ultra-wide high-toughness titanium alloy plate, characterized in that, It comprises the following steps: S1: mixing the required raw materials of the titanium alloy plate material and then pressing into several electrode blocks, and preparing large-size ingots through three times of VAR vacuum consumable arc melting; S2: performing multi-fire forging on the large-size ingots obtained in step S1, including high-temperature blooming forging of the ingots, forging below and above the phase transition point, two-phase zone forging and plate blank forming forging, to obtain a formed alloy plate blank; The high-temperature blooming forging of the ingot comprises placing the large-size ingot into a resistance heating furnace, first heating to 700-800 DEG C, holding for 2-3 h, then heating to a heating temperature of 1100-1150 DEG C, a holding coefficient of 0.6-0.7, upsetting and upsetting to a square billet with a height-diameter ratio of 1.7-2.0; a holding coefficient of 0.2-0.3 for reheat, upsetting and elongation forging after discharge, a total deformation of 70-80%, air cooling after forging, to obtain an alloy square billet; The below-transus forging and above-transus forging include heating the alloy bloom at T β - (20~35) °C, a holding coefficient of 0.6~0.7, heating to T β + (30~50) °C after being discharged and forged, a holding coefficient of 0.4~0.5, air cooling to room temperature after forging, to obtain an alloy forged bloom; The two-phase zone forging includes two to three heating forging at the phase transition point to improve the uniformity of the structure, and the forging heating temperature is T β - (20-30) ℃, holding coefficient 0.6-0.7, two times of return to furnace per heating, holding coefficient 0.2-0.3, air cooling after each heating forging, to obtain the alloy intermediate blank; in the forging at the phase transition point, the forging above the phase transition point and the two-phase zone forging, upsetting and elongation deformation are carried out after each heating, upsetting and elongation deformation of 70%-80% are carried out after return to furnace and temperature compensation, The slab forming and forging includes forging the alloy intermediate billet in a T... β Heating within a temperature range of 20~30℃, with a heat preservation coefficient of 0.6~0.7 and a reheat heat preservation coefficient of 0.2~0.3, the slab is widened and elongated to obtain an alloy slab. In the slab forming forging, the deformation amount of each widening and elongation is 10%~30%. After the slab width is widened to the predetermined value, only the slab is elongated. The deformation amount of the last two elongation deformations is controlled at 10%~15%. In step S2, after each upsetting and elongation forging, chamfering treatment is performed, the chamfering reduction L=(0.1-0.15)×square billet cross-section diagonal length, and grinding after forging, the depth-width ratio after grinding being less than 1:9; S3: plate rolling of the shaped alloy slab obtained in step S2 to obtain a finished plate; specifically, the plate rolling adopts gradient heating: first heating to T β - (60~70) °C for 1~2h, and then heating to T β - (20~30) °C at a holding coefficient of 1.5~1.8; after discharging, the slab is transversely spread and rolled with the long side of the slab as the width direction; after rolling to the predetermined width, the slab is returned to the furnace for 2~3h, and then longitudinally rolled to the finished size; in step S3, the pass reduction of the transverse rolling is 10~15mm, and the pass reduction of the longitudinal rolling is 7~15mm; S4: performing a finished product heat treatment on the finished product plate obtained in step S3, including performing annealing treatment and hot straightening; specifically, performing annealing treatment on the plate, the annealing temperature T β - (20~40) ℃, the heat preservation coefficient is 2~4, after discharging, high temperature is used for straightening, and after straightening, air cooling is performed to room temperature.

2. A large single unit weight, large thickness, ultra-wide high-toughness titanium alloy plate material, characterized in that, Prepared by the preparation method according to claim 1.

3. The large unit weight, large thickness, ultra-wide high-toughness titanium alloy plate according to claim 2, characterized in that, The titanium alloy plate material has a thickness of 100-200 mm, a width of 2000-3000 mm and a length of 4000-10000 mm.

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