A rolling method for producing a titanium alloy wide thin gauge plate by double covering

Abstract

The application discloses a rolling method for preparing titanium alloy wide-width thin-gauge plate through double-coating, and comprises the following steps: S1, after the initial blank is heated, first fire rolling is performed, and the rolled plate blank is returned to the furnace for online temperature compensation and then second fire rolling is performed, so that an intermediate blank is obtained; S2, the intermediate blank is cut into pieces, high-temperature oxidation-resistant release agents are brushed on the upper and lower surfaces, and after baking, a titanium alloy blank to be coated is obtained; S3, the titanium alloy blank to be coated is stacked up and down, a coating assembly is used for separation and coating, and then a first stack rolling package is prepared; S4, after the first stack rolling package is heated, 1-3 fire rolling is performed, and after overall annealing, a finishing process is performed, so that a first wide-width thin-gauge plate is obtained. The wide-width thin-gauge plate is prepared by adopting the double-coating method, the problems of surface cracking caused by the narrow hot working window of the titanium alloy are reduced, the intermediate blank is prepared by adopting two fire times, the deformation amount after coating rolling is ensured to be close to the rolling deformation amount of the intermediate blank, and the generation of anisotropy is avoided.

Description

Technical Field

[0001] This invention relates to the field of plastic processing technology for titanium metal materials, and in particular to a rolling method for preparing wide, thin titanium alloy plates with double cladding. Background Technology

[0002] TC11 titanium alloy is a high-strength, corrosion-resistant titanium alloy widely used in aerospace, shipbuilding, and chemical industries. With industrial development, the demand for wide-width, thin-gauge TC11 titanium alloy plates is increasing. However, traditional rolling methods for producing wide-width, thin-gauge plates are prone to problems such as poor surface quality, uneven thickness, and uneven internal structure, leading to unstable product performance.

[0003] When thinning to below 5mm using conventional rolling methods, edge cracks are prone to occur, with a width loss of ≥8%. Furthermore, the surface of TC11 titanium alloy is easily oxidized to form a brittle α-shell (thickness >50μm), leading to microcracks in subsequent rolling. During wide-width plate rolling, the edge temperature drops rapidly, reducing plastic deformation capacity and resulting in an edge crack incidence rate >15%. Although asynchronous rolling can improve deformation uniformity, plate shape control is difficult, and the plate unevenness is typically >5mm / m. After conventional hot rolling, the β-grain size distribution dispersion is >40%, and the grain size difference is >30%, resulting in large fluctuations in mechanical properties and prominent anisotropic force issues, leading to unstable product performance.

[0004] Currently, conventional rolling methods for titanium alloys typically include: (1) after the first rolling, reversing rolling is used to the finished product, so that the subsequent rolling direction is consistent after the plate is thinned by hot rolling, thereby avoiding the texture changes caused by changing the rolling direction during hot rolling; (2) make full use of the high temperature section of the first rolling to perform deformation with a large amount of deformation; (3) when rolling finished products below 6mm to 4mm, multiple tempering and reheating are required to ensure that the target size is achieved; (4) when rolling finished products below 4mm, the method of cladding steel plate is used for rolling.

[0005] The current rolling method has the following problems: (1) The plate is rolled in the direction after a reversal before cladding, which leads to the anisotropy of the mechanical properties of the final plate. (2) The heating temperature is inconsistent for each heat, and the finished product specifications lead to inconsistent rolling process, which is not conducive to batch production. (3) Conventional cladding of titanium alloy is 3 layers, and the size of the cladding steel plate is different, which requires a large number of steel plate sizes and specifications, resulting in low production efficiency.

[0006] In view of this, improvements should be made to the existing technology. Summary of the Invention

[0007] The main objective of this invention is to provide a rolling method for preparing wide-width, thin-gauge titanium alloy plates using a double-coating process. The double-coating effectively suppresses surface oxidation, oxygen infiltration, and edge cracking defects in TC11 titanium alloy during high-temperature rolling, significantly improving the surface quality, shape accuracy, thickness tolerance, flatness, and surface roughness of the plate, meeting the requirements for high-end aerospace materials. The rolling process exhibits improved stability, a significantly increased success rate in rolling wide-width, thin plates, and a substantial reduction in edge trimming and head / tail trimming losses. Simultaneously, this process shortens the production cycle, reduces the number of heating passes and surface grinding workload, effectively lowering production costs. It enables efficient, stable, and low-cost industrial production of wide-width, thin-gauge TC11 plates, meeting the demand for high-performance titanium alloy plates in key fields such as aero-engines and aerospace structural components. According to one aspect of the present invention, a rolling method for preparing wide, thin titanium alloy plates with double cladding is provided, comprising the following steps: S1. The initial billet is loaded into an electric heating roller hearth furnace, heated to the first heating temperature by the furnace, held at the temperature and then heated again. The heated billet is rolled in the first fire, and the rolled billet is returned to the furnace for online reheating and then rolled in the second fire to obtain the intermediate billet for cladding. S2. After pickling and surface grinding, the intermediate billet is cut and divided into materials. The upper and lower surfaces of the cut billet are coated with a high-temperature anti-oxidation release agent and baked to obtain the titanium alloy billet to be coated. S3. Stack multiple sets of titanium alloy billets of the same size to be coated one on one side, arrange them back and forth in the rolling direction, and use the coating component to separate and coat them to make the first rolling bale. S4. The first stack of rolled bales is placed into an electric heating furnace. After the furnace temperature stabilizes at the second heating temperature, it is kept at the temperature and then heated. The first stack of rolled bales is then rolled in 1 to 3 heats. After overall annealing, a finishing process is carried out to obtain the first wide thin-gauge sheet.

[0008] According to one embodiment of the present invention, the method further includes the following steps: S5. The first stack of rolled bales is divided into finished size plates. After straightening and surface treatment, the finished size plates are cut into semi-finished plates of the same size. The upper and lower surfaces of the semi-finished plates are coated with a high-temperature antioxidant release agent, baked, stacked, and arranged in front and back according to the rolling direction. After being separated and covered by a covering component, the second stack of rolled bales is made. S6. Place the second stack of rolled sheets into an electric heating furnace. After the furnace temperature stabilizes at the third heating temperature, maintain the temperature and heat it again. Then, roll the heated second stack of rolled sheets for 1 to 3 heats. After overall annealing, perform a finishing process to obtain the second wide thin sheet material.

[0009] According to one embodiment of the present invention, in step S1, the first heating temperature is 1020~1040℃, the total deformation of the first heat rolling is 50~70%, the deformation per pass is <30%, the number of passes is 5~7, the rolling speed is 2~4m / s, and the first heat rolling and the second heat rolling are unidirectional rolling.

[0010] According to one embodiment of the present invention, in step S1, the online heating time is 40~60min, the total deformation of the second rolling is 80~90%, the deformation per pass is <30%, the number of passes is 5~8, and the rolling speed is 1~2m / s.

[0011] According to one embodiment of the present invention, in step S2, the high-temperature antioxidant isolation agent includes BJDX-1, and the baking time is 20~40 min.

[0012] According to one embodiment of the present invention, step S3 further includes: Prepare the cladding assembly, which includes steel plates and edge strips. Stack 2-3 titanium alloy billets of the same size into a group, and arrange the two groups of stacked titanium alloy billets in the front and back according to the rolling direction. Two sets of billets are separated by edge strips and vent holes are opened on the edge strips. Then, steel plates and edge strips are used to cover and weld around the billets. Vent holes are opened on the front and back steel plates to make the first stack of rolled ladle.

[0013] According to one embodiment of the present invention, the thickness of the steel plate is 0.8 to 1.0 times the thickness of the titanium alloy billet to be coated, the edge strip includes head and tail edge strips and side edge strips, the length of the head and tail edge strips is the width of the titanium alloy billet to be coated + 20 to 30 mm, the length of the side edge strips is the length of the titanium alloy billet to be coated × 2 + 60 to 90 mm, the height of the edge strips is the thickness of the stacked titanium alloy billet to be coated, and the width of the edge strips is 15 to 20 mm.

[0014] According to one embodiment of the present invention, the length of the vent hole on the edge strip is 10~15mm, and the height is the thickness of the titanium alloy blank to be covered after stacking.

[0015] According to one embodiment of the present invention, in step S4, the second heating temperature is 880℃~920℃, the holding time is 1.5~2h, the total deformation of rolling in 1~3 heats is 75%~80%, the number of rolling passes is 6~8, and the rolling speed is 2~4m / s.

[0016] According to one embodiment of the present invention, in step S6, the second heating temperature is 880~920℃, the holding time is 1~1.5h, the total deformation of 1~3 heat rolling is 75~80%, the number of passes is 9~10, and the rolling speed is 1~2m / s.

[0017] According to an embodiment of the present invention, a rolling method for preparing wide-width thin-gauge titanium alloy plates using double-coating effectively suppresses surface oxidation, oxygen infiltration, and edge cracking defects of TC11 titanium alloy during high-temperature rolling. This significantly improves the surface quality and shape accuracy of the plate, as well as thickness tolerance, flatness, and surface roughness, meeting the requirements for high-end aerospace materials. The rolling process stability is improved, and the rolling success rate of wide-width thin plates is significantly increased, while edge trimming and head / tail trimming losses are significantly reduced. Simultaneously, this process shortens the production cycle, reduces the number of heating passes and surface grinding workload, effectively lowering production costs. It achieves efficient, stable, and low-cost industrial production of TC11 wide-width thin-gauge plates, meeting the demand for high-performance titanium alloy plates in key fields such as aero-engines and aerospace structural components. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some implementation examples of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A process flow diagram of a rolling method for preparing wide-width thin-gauge titanium alloy plates with double cladding according to an exemplary embodiment of the present invention is shown. Figure 2 A schematic diagram of a double-layered encapsulation structure according to an exemplary embodiment of the present invention is shown; Figure 3 A metallographic microstructure of a wide, thin sheet of TC11 titanium alloy according to an exemplary embodiment of the present invention is shown. Figure 4 A metallographic microstructure of a wide, thin sheet of TC11 titanium alloy according to an exemplary embodiment of the present invention is shown. Figure 5 A metallographic microstructure of a wide, thin sheet of TC11 titanium alloy according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0020] The following detailed description of the embodiments is intended to exemplify the principles of the present invention, but should not be construed as limiting the scope of the invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0021] These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0022] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0024] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0025] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0026] like Figure 1 As shown, this invention provides a rolling method for preparing wide, thin titanium alloy plates using double-coating, comprising the following steps: S1. The initial billet is loaded into an electric heating roller hearth furnace and heated to the first heating temperature by the furnace. After being heated for a period of time, the billet is subjected to the first fire rolling. The rolled billet is returned to the furnace for online reheating for a period of time and then subjected to the second fire rolling to obtain the intermediate billet for coating. S2. After pickling and surface grinding, the intermediate billet is cut and divided into materials. The upper and lower surfaces of the cut billet are coated with a high-temperature anti-oxidation release agent. After baking and drying, the titanium alloy billet to be coated is obtained. S3. Stack multiple sets of titanium alloy billets of the same size to be coated one on one side, arrange them back and forth in the rolling direction, and use the coating component to separate and coat them to make the first rolling bale. S4. The first stack of rolled bales is placed into an electric heating furnace. The electric heating furnace is heated to the second heating temperature. After the furnace temperature stabilizes at the second heating temperature, it is kept at the temperature and then the heating process is carried out. Then, the first stack of rolled bales after heating is rolled for 1 to 3 heats. After overall annealing, a finishing process is carried out to obtain the first wide thin-gauge sheet.

[0027] The rolling method for preparing wide-width thin-gauge titanium alloy plates according to embodiments of the present invention effectively suppresses surface oxidation, oxygen infiltration, and edge cracking defects of TC11 titanium alloy during high-temperature rolling through double-coating protection. This significantly improves the surface quality, shape accuracy, thickness tolerance, flatness, and surface roughness of the plate, meeting the requirements of high-end aerospace materials. The rolling process stability is improved, the rolling success rate of wide-width thin plates is significantly increased, and edge trimming and head / tail trimming losses are significantly reduced. Simultaneously, this process shortens the production cycle, reduces the number of heating passes and surface grinding workload, effectively reducing production costs. It achieves efficient, stable, and low-cost industrial production of TC11 wide-width thin-gauge plates, meeting the demand for high-performance titanium alloy plates in key fields such as aero-engines and aerospace structural components. In some embodiments of the present invention, the dimensions of the wide-width thin-gauge plates are: 0.4mm ≤ thickness ≤ 3.0mm, and width ≥ 1500mm.

[0028] In some specific embodiments, the method further includes the following steps: S5. After the first stack of rolled bales has been rolled 1 to 3 times, the finished size of the bales is obtained. After straightening and surface treatment, the finished size bales are cut into semi-finished bales of the same size that can be covered. The upper and lower surfaces of the semi-finished bales are coated with a high-temperature antioxidant release agent. After baking and drying, they are stacked up and down and arranged in front and back according to the rolling direction. After being separated and covered by the covering components, the second stack of rolled bales is made. S6. The second stack of rolled bales is placed into an electric heating furnace. The electric heating furnace is heated to the third heating temperature. After the furnace temperature stabilizes at the third heating temperature, it is kept at the temperature and then heated again. The heated second stack of rolled bales is then rolled in 1 to 3 heats. After overall annealing, a finishing process is carried out to obtain the second wide thin-gauge sheet.

[0029] In step S5, the thickness of the semi-finished board is 2.0~3.0mm.

[0030] The second wide-width thin sheet has a thickness of 0.4~0.6mm and a width of ≥1500mm.

[0031] Based on the above embodiments, in step S1, the first heating temperature is 1020~1040℃, the total deformation of the first rolling is 50~70%, preferably 60%, the deformation per pass is <30%, the number of passes is 5~7, the rolling speed is 2~4m / s, the two-fire rolling is unidirectional rolling (i.e. the rolling direction is the same), without reversing direction, the thickness of the intermediate billet is 8~15mm, and the holding time is 3~4.5h.

[0032] In some specific embodiments, in step S1, the online heating time is 40~60min, the total deformation of the second rolling is 80~90%, preferably 85%, the deformation per pass is <30%, the number of passes is 5~8, the rolling speed is 1~2m / s, and the rolling method with fewer passes and larger deformation rate is adopted, so that the rolling deformation penetrates into the core of the plate, ensuring that the structure of the slab is uniform.

[0033] Based on the above embodiments, in step S2, the high-temperature antioxidant release agent includes BJDX-1, the baking time is 20~40 min, and the thickness tolerance of the slab after grinding meets ±0.50 (mm) and the surface roughness is ≤1.6μm. BJDX-1 includes a nitride release agent, which uses nitrides such as boron nitride and silicon nitride as core components, and utilizes their high temperature resistance, chemical inertness, and non-adhesion properties to form a release layer between the two materials.

[0034] In step S2, during the material cutting process, titanium alloy billets with a width > 1500 mm are cut from the length side of the intermediate billet prepared in step S1 for the next cladding step, which will be used as the slab width for subsequent cladding rolling.

[0035] In some specific embodiments, the fabrication of the stacked package in steps S3 and S5 further includes: like Figure 2 As shown, prepare the cladding assembly, which includes steel plates and edge strips. Stack 2-3 titanium alloy billets of the same size to be clad into a group, and prepare a total of two groups. Place the two groups of stacked titanium alloy billets to be clad back and forth in the rolling direction. Two sets of billets are separated by edge strips and vent holes are opened on the edge strips. Then, steel plates and edge strips are used to cover and weld around the billets. Vent holes are opened on the front and rear steel plates to make a first stack or a second stack of rolled billets. The roughness of the contact surface between the steel plate and the titanium alloy billet is ≤2.0μm.

[0036] The steel plate and edge strip used for cladding are made of 316L stainless steel.

[0037] Based on the above embodiments, the thickness of the steel plate is 0.8 to 1.0 times the thickness of the titanium alloy billet to be coated. The edge strips include head and tail edge strips and side edge strips. The length of the head and tail edge strips is the width of the titanium alloy billet to be coated + 20 to 30 mm. The length of the side edge strips is the length of the titanium alloy billet to be coated × 2 + 60 to 90 mm. The height of the edge strips is the thickness of the stacked titanium alloy billet to be coated. The width of the edge strips is 15 to 20 mm. The edge strips used for the middle grid have the same dimensions as the head and tail edge strips.

[0038] The steel plate, edge strip, and high-temperature antioxidant in step S5 are the same as the materials used for coating in step S3, and their dimensions are also the same as those in step S3. The location and size of the vent holes are also the same as those in step S3.

[0039] In some specific embodiments, the length of the vent holes on the edge strip is 10~15mm, preferably 10mm, the height is the thickness of the titanium alloy blank to be covered after stacking, and the number of vent holes is two for the head and tail edge strips and two for the middle edge strip.

[0040] Based on the above embodiments, in step S4, the second heating temperature is 880℃~920℃, the holding time is 1.5~2h, the total deformation of 1~3 heat rolling is 75%~80%, the number of rolling passes is 6~8, the rolling speed is 2~4m / s, and the rolling method is to use the direction with a cutting width >1500mm as the width for rolling in step S2. This step controls the number of rolling passes and performs rapid rolling, effectively ensuring the shape and surface quality of the finished slab in the next step.

[0041] Based on the above embodiments, in step S6, the second heating temperature is 880~920℃, the holding time is 1~1.5h, the total deformation of 1~3 fire rolling is 75~80%, the number of passes is 9~10, the rolling speed is 1~2m / s, and the rolling direction is the same as in step S4. This step effectively improves the surface quality and comprehensive mechanical properties of the plate.

[0042] In step S4, the finishing process includes straightening after overall annealing, slitting, surface treatment, and length setting.

[0043] The thickness of the first wide-width thin sheet is 2.0~3.0mm, and the width is ≥1500mm.

[0044] Steps S1-S4 involve heating the TC11 titanium alloy in an electric furnace according to the forging billet, then rolling it in the first heat. After the rolled billet is returned to the furnace for online reheating for a certain period of time, it is rolled in the second heat. The intermediate billet is then surface pickled, surface ground, and cut into pieces. The upper and lower surfaces of the cut billet are coated with a high-temperature anti-oxidation release agent. After being covered with steel billet, it is heated and rolled in 2-3 heats. After heat treatment annealing and plate separation, TC11 titanium alloy wide thin sheet is obtained.

[0045] Combining the excellent deformation performance of TC11 titanium alloy at high temperatures above its phase transformation point, forming a fine strip-like structure, TC11 titanium alloy has good processing plasticity, reducing defects such as edge cracks and surface cracks caused by rolling. At the same time, due to the hereditary nature of the structure, it ensures the formation of fine equiaxed primary α phase + fine lamellar secondary α phase during subsequent rolling. Furthermore, the use of a double-cladding method in the subsequent cladding process solves the problems of excessive cladding layers, excessive overall thickness, uneven edge shape of titanium plates in each layer, and excessive deformation leading to cladding cracking that occur in conventional cladding methods.

[0046] By combining the reversing rolling of the plates before and after cladding (i.e., the rolling direction in step S4 is perpendicular to the rolling direction in step S1), and ensuring that the deformation amounts before and after the reversal are essentially the same, the problem of significant differences in the mechanical properties of the plates in the transverse and longitudinal directions due to the different deformation amounts in various directions is effectively solved, thus improving the overall mechanical properties of the plates. Furthermore, the cladding material dimensions of this invention are within a certain range, and the cladding material dimensions used for different specifications of titanium alloy plates are basically the same, reducing the pressure of material preparation and pressing during actual production.

[0047] After implementation of this invention, by selecting temperatures above the phase transformation point and using non-reversing rolling, surface and edge cracking of the billet during large deformation is avoided. Simultaneously, dynamic recrystallization occurs, forming equiaxed β-recrystallized grains, which can significantly control the microstructure and refine the grains in subsequent rolling. Using two passes to prepare the intermediate billet ensures that the deformation after cladding rolling is close to that of the intermediate billet, avoiding anisotropy. Reversing rolling is used during cladding rolling, reducing the reversing process during intermediate billet preparation. The use of a double-cladding method to prepare wide, thin plates reduces surface cracking caused by the narrow hot working window of titanium alloys. It solves the problem of easy oxidation of the titanium alloy surface to form a brittle α-shell (thickness > 50 μm), leading to microcracks in subsequent rolling. Furthermore, due to the reduced edge temperature drop during cladding rolling of wide, thin plates, plastic deformation capacity is improved, and the edge cracking rate is reduced. The increased amount of titanium alloy cladding improves rolling efficiency and reduces production costs.

[0048] The present application will be described in detail below through specific embodiments.

[0049] Example 1 This embodiment includes the following steps: S1. A TC11 titanium alloy billet with dimensions of 210mm×1500mm×1550mm (thickness×width×length) is placed in an electric furnace at a furnace temperature of 1030℃ and held for 3.5 hours. The heated billet is then rolled in the first pass, for a total of 5 passes. The pass percentages for each pass are 19.04%, 17.64%, 17.86%, 17.39%, and 18.95%, respectively, with a deformation of 63.33% per pass. The rolling speed was 2 m / s, and the billet thickness after rolling was 77 mm. The rolled slab was then returned to the furnace for online reheating at 1030℃ for 55 min. The reheated slab was then subjected to a second rolling pass with the following pass percentages: 22.08%, 25.00%, 26.67%, 27.27%, 29.17%, 29.41%, and 16.67%, respectively. The deformation per pass was 87.01%. The rolling speed was 2 m / s, and the billet thickness after rolling was 10 mm, resulting in a rolled slab size of 10 mm × 1500 mm × 32550 mm.

[0050] S2. The intermediate billet obtained in step S1 is pickled, surface-grinding and then cut into pieces to obtain a billet size of 10mm×1500mm×1500mm. The upper and lower surfaces of the cut billet are coated with BJDX-1 high-temperature anti-oxidation release agent and baked for 30 minutes. After the surface is dry, the titanium alloy billet to be coated is obtained. The thickness tolerance of the billet after grinding meets ±0.50 (mm) and the surface roughness ≤1.6μm.

[0051] S3. Prepare the steel plate and edge strip for cladding. Stack three titanium alloy intermediate billets of the same size from step S2 on top of each other, and prepare two sets in total. Place the two sets of stacked titanium alloy intermediate billets back and forth in the rolling direction. Use steel strips to separate the two sets of billets and open vent holes on the steel strips. Then use steel plates and steel strips to clad and weld around the perimeter. Open vent holes on the front and back steel plates to make the first stacked ladle. The roughness of the contact surface between the steel plate and the titanium plate is ≤2.0μm. The size of the cladding material is 90mm×1570mm×3130mm.

[0052] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 30mm. The length of the head and tail edge strips is 1530mm. The length of the side edge strips is 3090mm. All edge strips are 30mm high and 20mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head and tail edge strips and the middle edge strips. The length of each vent hole is 10mm. The dimensions of the upper and lower cladding steel plates are 30mm × 1570mm × 3130mm.

[0053] S4. The first stack of rolled ladle made in step S3 is placed into an electric heating furnace that has been heated to the heating temperature. The furnace is then kept at 920°C for 2 hours. The heated stack of rolled ladle is then rolled in one pass with a reversing rolling process. The pass distribution for each pass is 25.00%, 26.67%, 27.27%, 28.00%, and 29.98%, with a deformation of 80%. The rolling speed is 2 m / s, and the thickness of the rolled plate is 2 mm. After rolling, the plate is then subjected to overall annealing, straightening, slitting, surface treatment, and length setting to obtain TC11 wide thin plate with dimensions of 2 mm × 1500 mm × 7500 mm.

[0054] S5. The first stack of rolled sheets from step S4 is slid into plates of finished size. These plates are then straightened, surface-treated, and cut to the same dimensions: 2mm × 1500mm × 1500mm. This yields semi-finished plates suitable for cladding. The upper and lower surfaces of the cut blanks are coated with BJDX-1 high-temperature antioxidant release agent and baked for 30 minutes until completely dry. This results in titanium alloy blanks ready for cladding. After grinding, the blank thickness tolerance meets ±0.50 mm, and the surface roughness ≤ 1.6 μm. Step S3 is then repeated, with the cladding material dimensions being 18mm × 1570mm × 3130mm.

[0055] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 6mm. The length of the head and tail edge strips is 1530mm. The length of the side edge strips is 3090mm. All edge strips are 30mm high and 20mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head and tail edge strips and the middle edge strips. The length of each vent hole is 10mm. The dimensions of the upper and lower cladding steel plates are 6mm × 1570mm × 3130mm.

[0056] S6. The second stack of rolled ladle prepared in step S3 is placed into an electric heating furnace that has been heated to the heating temperature. The furnace is held at 900℃ for 1.5 hours. Then, the heated stack of rolled ladle is rolled in one pass with a reverse rolling direction. The pass percentages for each pass are: 25.00%, 23.33%, 21.74%, 27.78%, and 23.08%. The deformation is 80%, the rolling speed is 2 m / s, and the thickness of the rolled plate is 0.5 mm. Then, after overall annealing, straightening, slitting, surface treatment, and length setting, TC11 wide-width thin sheet material is obtained, with sheet dimensions of 0.5mm × 1500mm × 7500mm.

[0057] Testing revealed that the TC11 titanium alloy wide-width thin-gauge sheet prepared in this embodiment has a smooth and clean surface, a room temperature tensile strength of 1080 MPa, a yield strength of 998 MPa, an elongation after fracture of 16.6%, a difference in transverse and longitudinal mechanical properties ≤25 MPa, a high-temperature tensile strength of 700 MPa at 400℃, and a yield strength of 602 MPa. This indicates that the sheet exhibits high room temperature and high-temperature mechanical properties, and also has good surface quality.

[0058] Figure 3 The image shows the metallographic microstructure of the TC11 titanium alloy wide-width thin sheet prepared in this embodiment. As can be seen from the image, the microstructure of the prepared sheet consists of fine equiaxed primary α phase and fine lamellar intergranular β phase.

[0059] Example 2 This embodiment includes the following steps: S1. A TC11 titanium alloy billet with dimensions of 180mm×1500mm×1600mm (thickness×width×length) is placed in an electric furnace at a furnace temperature of 1030℃ and held for 3 hours. The heated billet is then rolled in the first pass, for a total of 5 passes. The pass percentages for each pass are 22.22%, 21.43%, 22.72%, 21.05%, and 21.43%, respectively, with a total deformation of 69.44%. The rolling speed was 2 m / s, and the thickness of the rolled billet was 55 mm. The rolled slab was then returned to the furnace for online reheating at 1030℃ for 40 minutes. The reheated slab was then subjected to a second rolling pass with the following pass percentages: 27.27%, 25.00%, 26.67%, 27.31%, 25.00%, and 25.00%, respectively. The deformation per pass was 83.63%. The rolling speed was 2 m / s, and the thickness of the rolled billet was 10 mm, resulting in a rolled slab size of 9 mm × 1500 mm × 32000 mm.

[0060] S2. The intermediate billet obtained in step S1 is pickled, surface-grinding and then cut into pieces to obtain a billet size of 9mm×1500mm×1500mm. The upper and lower surfaces of the cut billet are coated with BJDX-1 high-temperature anti-oxidation release agent and baked for 30 minutes. After the surface is dry, the titanium alloy billet to be coated is obtained. The thickness tolerance of the billet after grinding meets ±0.50 (mm) and the surface roughness is ≤1.6μm.

[0061] S3. Prepare the steel plate and edge strip for cladding. Stack three titanium alloy intermediate billets of the same size from step S2 on top of each other, and prepare two sets in total. Place the two sets of stacked titanium alloy intermediate billets back and forth in the rolling direction. Use steel strips to separate the two sets of billets and open vent holes on the steel strips. Then, use steel plates and steel strips to clad and weld around the perimeter. Open vent holes on the front and back steel plates to make the first stacked ladle. The roughness of the contact surface between the steel plate and the titanium plate is ≤2.0μm. The size of the cladding material is 81mm×1560mm×3100mm.

[0062] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 27mm. The length of the head and tail edge strips is 1520mm. The length of the side edge strips is 3060mm. All edge strips are 27mm high and 15mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head, tail, and middle edge strips, with each vent hole being 10mm long. The dimensions of the upper and lower cladding steel plates are 27mm × 1560mm × 3100mm.

[0063] S4. The first stack of rolled ladles prepared in step S3 is placed into an electric heating furnace that has been preheated to the heating temperature. The furnace is held at 920℃ for 1.8 hours. Then, the heated stack of rolled ladles is rolled in one pass with a reverse rolling direction. The pass percentages for each pass are 22.22%, 28.99%, 28.57%, and 28.57%, respectively. The deformation is 72.22%, the rolling speed is 2 m / s, and the thickness of the rolled plate is 2.5 mm. Then, after overall annealing, straightening, slitting, surface treatment, and length setting, TC11 wide-width thin sheet material is obtained, with sheet dimensions of 2.5mm × 1500mm × 5400mm.

[0064] S5. The first stack of rolled sheets from step S4 is slid into plates of finished size. These plates are then straightened, surface-treated, and cut to the same dimensions: 2.5mm × 1500mm × 1500mm. This yields semi-finished plates suitable for cladding. The upper and lower surfaces of the cut blanks are coated with BJDX-1 high-temperature antioxidant release agent and baked for 30 minutes until completely dry. This results in titanium alloy blanks ready for cladding. After grinding, the blank thickness tolerance meets ±0.50 mm, and the surface roughness ≤1.6 μm. Step S3 is then repeated, with the cladding material dimensions being 22.5mm × 1560mm × 3100mm.

[0065] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 7.5mm. The length of the head and tail edge strips is 1520mm. The length of the side edge strips is 3060mm. All edge strips are 7.5mm high and 15mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head and tail edge strips and the middle edge strips. The length of each vent hole is 10mm. The dimensions of the upper and lower cladding steel plates are 7.5mm × 1560mm × 3100mm.

[0066] S6. The second stack of rolled ladle prepared in step S3 is placed into an electric heating furnace that has been heated to the heating temperature. The furnace is held at 900℃ for 1.5 hours. Then, the heated stack of rolled ladle is rolled in one pass with a reverse rolling direction. The pass percentages for each pass are: 28.00%, 27.78%, 23.08%, 25.00%, and 20.00%. The deformation is 76%, the rolling speed is 2 m / s, and the thickness of the rolled plate is 0.5 mm. Then, after overall annealing, straightening, slitting, surface treatment, and length setting, TC11 wide-width thin sheet material is obtained, with sheet dimensions of 0.6mm×1500mm×6250mm.

[0067] Testing revealed that the TC11 titanium alloy wide-width thin-gauge sheet prepared in this embodiment has a smooth and clean surface. Its room temperature tensile strength is 1124 MPa, yield strength is 1016 MPa, elongation after fracture is 15.7%, and the difference in mechanical properties between the transverse and longitudinal directions is ≤35 MPa. At 400℃, its high-temperature tensile strength is 691 MPa, and its yield strength is 618 MPa. This indicates that the sheet exhibits high room temperature and high-temperature mechanical properties, and also has good surface quality.

[0068] Figure 4 The image shows the metallographic microstructure of the TC11 titanium alloy wide-width thin sheet prepared in this embodiment. As can be seen from the image, the microstructure of the prepared sheet consists of fine equiaxed primary α phase and fine lamellar intergranular β phase.

[0069] Example 3 This embodiment includes the following steps: S1. A TC11 titanium alloy billet with dimensions of 220mm×1500mm×1550mm (thickness×width×length) is placed in an electric furnace at a furnace temperature of 1030℃ and held for 4.5 hours. The heated billet is then rolled in the first pass, for a total of 4 passes. The pass percentages for each pass are 18.19%, 22.22%, 21.43%, and 27.27%, respectively, and the deformation per pass is 63.64%. The rolling speed is 2 m / s, and the thickness of the rolled billet is 80 mm. The rolled slab is then returned to the furnace for online reheating at 1030℃ for 60 minutes. The reheated slab is then subjected to a second rolling pass with the following pass percentages: 28.75%, 29.82%, 27.50%, 27.59%, 28.57%, 26.67%, and 27.27%, respectively. The deformation per pass is 90%. The rolling speed is 2 m / s, and the thickness of the rolled billet is 10 mm, resulting in a rolled slab size of 8 mm × 1500 mm × 42625 mm.

[0070] S2. The intermediate billet obtained in step S1 is pickled, surface-grinding and then cut into pieces to obtain a blank size of 8mm×1500mm×1500mm. The upper and lower surfaces of the cut blank are coated with BJDX-1 high-temperature anti-oxidation release agent and baked for 30 minutes. After the surface is dry, the titanium alloy blank to be coated is obtained. The thickness tolerance of the blank after grinding meets ±0.50 (mm) and the surface roughness ≤1.6μm.

[0071] S3. Prepare the steel plate and edge strip for cladding. Stack three titanium alloy intermediate billets of the same size from step S2 on top of each other, and prepare two sets in total. Place the two sets of stacked titanium alloy intermediate billets back and forth in the rolling direction. Use steel strips to separate the two sets of billets and open vent holes on the steel strips. Then, use steel plates and steel strips to clad and weld around the perimeter. Open vent holes on the front and back steel plates to make the first stacked ladle. The roughness of the contact surface between the steel plate and the titanium plate is ≤2.0μm. The size of the cladding material is 72mm×1580mm×3140mm.

[0072] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 24mm. The length of the head and tail edge strips is 1530mm. The length of the side edge strips is 3080mm. All edge strips are 24mm high and 15mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head and tail edge strips and the middle edge strips. The length of each vent hole is 10mm. The dimensions of the upper and lower cladding steel plates are 24mm × 1580mm × 3140mm.

[0073] S4. The first stack of rolled ladles prepared in step S3 is placed into an electric heating furnace that has been preheated to the heating temperature. The furnace is held at 920℃ for 1.5 hours. Then, the heated stack of rolled ladles is rolled in one pass with a reverse rolling direction. The pass percentages for each pass are: 20.49%, 25.32%, 27.00%, 26.99%, and 22.45%. The deformation is 75%, the rolling speed is 2 m / s, and the thickness of the rolled plate is 2.0 mm. Then, after overall annealing, straightening, slitting, surface treatment, and length setting, TC11 wide-width thin sheet material is obtained, with sheet dimensions of 2.0mm×1500mm×6000mm.

[0074] S5. The first stack of rolled sheets from step S4 is slid into plates of finished size. These plates are then straightened, surface-treated, and cut to the same dimensions: 2.0mm × 1500mm × 1500mm. This yields semi-finished plates suitable for cladding. The upper and lower surfaces of the cut blanks are coated with BJDX-1 high-temperature antioxidant release agent and baked for 40 minutes until completely dry. This results in titanium alloy blanks ready for cladding. After grinding, the blank thickness tolerance meets ±0.50 mm, and the surface roughness ≤ 1.6 μm. Step S3 is then repeated, with the cladding material dimensions being 18mm × 1580mm × 3140mm.

[0075] The steel plates and edge strips used for cladding are made of 316L stainless steel. The thickness of the steel plates covering the upper and lower surfaces is 6mm. The length of the head and tail edge strips is 1530mm. The length of the side edge strips is 3080mm. All edge strips are 6mm high and 15mm wide. The steel strips used for the middle partitions are the same size as the head and tail edge strips. Two vent holes are provided on the head, tail, and middle edge strips, with each vent hole being 10mm long. The dimensions of the upper and lower cladding steel plates are 6mm × 1580mm × 3140mm.

[0076] S6. The second stack of rolled ladle prepared in step S3 is placed into an electric heating furnace that has been heated to the heating temperature. The ladle is held at 900℃ for 1.0 hour. Then, the heated stack of rolled ladle is rolled in one pass with a reverse rolling direction. The pass percentages for each pass are: 27.78%, 28.00%, 25.00%, 23.08%, and 20.00%. The deformation is 80%, the rolling speed is 2 m / s, and the thickness of the rolled plate is 0.5 mm. Then, after overall annealing, straightening, slitting, surface treatment, and length setting, TC11 wide-width thin sheet material is obtained, with sheet dimensions of 0.4mm × 1500mm × 7500mm.

[0077] Testing revealed that the TC11 titanium alloy wide-width thin-gauge sheet prepared in this embodiment has a smooth and clean surface, a room temperature tensile strength of 1054 MPa, a yield strength of 981 MPa, an elongation after fracture of 17.2%, a difference in transverse and longitudinal mechanical properties ≤30 MPa, and a high-temperature tensile strength of 714 MPa and a yield strength of 623 MPa at 400℃. This indicates that the sheet exhibits high room temperature and high-temperature mechanical properties, and also possesses good surface quality.

[0078] Figure 5 The image shows the metallographic microstructure of the TC11 titanium alloy wide-width thin sheet prepared in this embodiment. As can be seen from the image, the microstructure of the prepared sheet consists of fine equiaxed primary α phase and fine lamellar intergranular β phase.

[0079] The beneficial effects of implementing this invention include: (1) In the first rolling process, deformation is carried out at high temperature above the phase transformation point to form a fine strip structure, which ensures that TC11 titanium alloy has good processing plasticity and reduces defects such as edge cracks and surface cracks caused by rolling. At the same time, due to the hereditary nature of the structure, it ensures that fine equiaxed primary α phase + fine lamellar secondary α phase are formed in the subsequent rolling process.

[0080] (2) The double-coating method is adopted for rolling, which solves the problems of excessive coating layers, excessive overall thickness, uneven edge shape of each titanium plate during rolling, excessive deformation leading to coating cracking in conventional coating methods, thus improving production efficiency, yield, and reducing production costs.

[0081] (3) Based on ensuring the production process of TC11 titanium alloy wide and thin sheet, the size of the cladding material is within a certain range. The size of the cladding material used for different titanium alloy sheets is basically the same, which reduces the pressure of material preparation and pressing in the actual production process.

[0082] (4) Combine the reversing rolling of the plates before and after the coating, and the deformation before and after the reversing is basically the same, which effectively reduces the micro and macro texture caused by the different deformation in each direction, resulting in a large difference in the mechanical properties of the plates in the transverse and longitudinal directions, thus improving the comprehensive mechanical properties of the plates.

[0083] (5) Adapt to industrial hot rolling production lines. For target products with larger dimensions and wider plate widths, a double-layer-wrapping method is adopted to meet the target size requirements and avoid the phenomenon that the plate size does not meet the heating and rolling requirements of the production line.

[0084] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0085] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A rolling method for preparing wide, thin titanium alloy plates using double-coating, characterized in that, Includes the following steps: S1. The initial billet is loaded into an electric heating furnace and heated at the first heating temperature. The heated billet is rolled in the first fire. The rolled billet is returned to the furnace for online reheating and then rolled in the second fire to obtain the intermediate billet for cladding. S2. Cut the intermediate billet into smaller pieces, and apply a release agent to the upper and lower surfaces of the cut billet to obtain the titanium alloy billet to be coated. S3. Combine multiple titanium alloy billets to be coated into two groups of billets. Each group of billets includes multiple titanium alloy billets of the same size stacked on top of each other. Place the two groups of billets back and forth in the rolling direction, separate them with a separator, and coat them with a coating component to make the first rolling package. S4. The first stacked roll is placed into an electric heating furnace and heated at a second heating temperature. Then, the heated first stacked roll is rolled and post-processed to obtain a first wide thin sheet.

2. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 1, characterized in that, The method further includes the following steps: S5. The first stack of rolled sheet is divided into a sheet, which is then cut into semi-finished sheets of the same size. A release agent is applied to the upper and lower surfaces of the semi-finished sheets to obtain sheets to be covered. Multiple sheets to be covered are combined into two groups of sheets, each group of sheets including multiple sheets to be covered stacked on top of each other. The two groups of sheets are arranged back and forth in the rolling direction, separated by a separator and covered by a covering component to form a second stack of rolled sheet. S6. The second stack of rolled bales is placed into an electric heating furnace and heated at a third heating temperature. Then, the heated second stack of rolled bales is rolled and post-processed to obtain a second wide-width thin sheet.

3. The rolling method for preparing wide, thin titanium alloy plates with double cladding according to claim 2, characterized in that, In step S1, the first heating temperature is 1020~1040℃, the total deformation of the first fire rolling is 50~70%, the deformation per pass is <30%, the number of passes is 5~7, the rolling speed is 2~4m / s, and the first fire rolling and the second fire rolling are unidirectional rolling.

4. The rolling method for preparing wide, thin titanium alloy plates with double cladding according to claim 1, characterized in that, In step S1, the online heating time is 40-60 min, the total deformation of the second heat rolling is 80-90%, the deformation per pass is <30%, the number of passes is 5-8, and the rolling speed is 1-2 m / s.

5. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 1, characterized in that, In step S2, the release agent is a high-temperature antioxidant release agent. After applying the release agent, the product is baked for 20 to 40 minutes.

6. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 1, characterized in that, In step S3, the two sets of blanks are separated by a separator and covered by a covering assembly, including: separating the two sets of blanks with a side strip and opening vent holes on the side strip; using steel plates and side strips to cover and weld the two sets of blanks around their perimeter, and opening vent holes on the front and rear steel plates.

7. The rolling method for preparing wide, thin titanium alloy plates with double cladding according to claim 6, characterized in that, The thickness of the steel plate is 0.8 to 1.0 times the thickness of the titanium alloy billet to be coated. The edge strips used for coating include head and tail edge strips and side edge strips. The length of the head and tail edge strips is the width of the titanium alloy billet to be coated + 20 to 30 mm. The length of the side edge strips is the length of the titanium alloy billet to be coated × 2 + 60 to 90 mm. The height of the edge strips used for coating is the thickness of the stacked titanium alloy billet to be coated, and the width is 15 to 20 mm.

8. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 6, characterized in that, The length of the vent holes on the edge strip used for separation is 10~15mm, and the height of the edge strip used for separation is the thickness of the stacked titanium alloy blank to be covered.

9. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 1, characterized in that, In step S4, the second heating temperature is 880℃~920℃, the holding time is 1.5~2h, and rolling is performed in 1~3 heats. The total deformation of the rolling is 75%~80%, the number of rolling passes is 6~8, and the rolling speed is 2~4m / s. The rolling direction of step S4 is perpendicular to the rolling direction of step S1.

10. The rolling method for preparing wide, thin titanium alloy plates by double-coating according to claim 2, characterized in that, In step S6, the third heating temperature is 880~920℃, the holding time is 1~1.5h, and rolling is performed in 1~3 heats. The total deformation of the rolling is 75~80%, the number of passes is 9~10, and the rolling speed is 1~2m / s.

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