A rolling process for efficiently preparing near-alpha high-temperature titanium alloy foil

Abstract

The application provides a rolling process for efficiently preparing near-alpha high-temperature titanium alloy foil, which comprises the following steps: cutting a near-alpha high-temperature titanium alloy slab into a blank, covering the surface of 2-4 pieces of the blank with a steel plate, and preparing a cladding rolling package through argon arc welding; the obtained cladding rolling package is kept in a heating furnace for t1 min, and rolling is performed to obtain a blank with a thickness of 1.0+ / -0.1 mm; the cladding rolling package is kept in a heating furnace for t2 min, and rolling is performed to obtain a blank with a thickness of 0.13+ / -0.04 mm; the blank obtained in S3 is removed from the cladding rolling layer after creep correction, and a semi-finished product foil is obtained; after alkaline and acid washing, a rolled foil with a thickness of 0.08-0.15 mm is obtained; the rolled foil is placed in a vacuum furnace for vacuum annealing treatment, and a finished product foil with a thickness of 0.08-0.15 mm is obtained. The application only uses a hot rolling process during rolling, the process is short and efficient, the requirements for the rolling equipment are reduced, and the cracking defects caused by surface temperature drop in the hot rolling process are avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of titanium alloy material processing, and particularly relates to a rolling process for efficiently preparing near-alpha type high-temperature titanium alloy foil. BACKGROUND

[0002] The near-alpha type high-temperature titanium alloy has the advantages of high specific strength, light weight and excellent high-temperature performance. The long-time use temperature of the near-alpha type high-temperature titanium alloy Ti65 titanium alloy independently researched and developed by China can reach 650 DEG C. The main semi-finished product of the alloy is a plate, and the alloy has been widely applied to high-temperature structural components such as cylinder bodies and wings of aero-engines and supersonic aircrafts.

[0003] The high-temperature titanium alloy foil has become the main titanium alloy semi-finished product of the wing honeycomb wall plate and other components of the aerospace aircraft and the supersonic aircraft due to the advantages of light weight, high strength and high temperature resistance. In the two patents with the announcement number CN113578959A and CN113578967A, the mechanical properties are mainly optimized by regulating the rolling process, but the influence of anisotropy on the mechanical properties of the material is ignored.

[0004] The anisotropy of the titanium alloy is closely related to the texture. The research of Abarbekoh et al. in Materials & Design (2012, 37, 223-227) shows that the titanium alloy with transverse texture has strong mechanical anisotropy, and the mechanical anisotropy of the titanium alloy with basal texture is weaker.

[0005] At present, most of the patents at home and abroad related to the preparation of the high-temperature titanium alloy foil need to combine the hot rolling and cold rolling processes, and the process is complex and the cycle is long. With the increase of the flight speed of the aerospace supersonic aircraft, the demand for the high-temperature titanium alloy foil of the honeycomb wall plate structure is increasingly urgent. Therefore, the efficient preparation method of the high-temperature titanium alloy foil is an urgent problem to be solved. SUMMARY

[0006] The technical problem to be solved by the application is to provide a rolling process for efficiently preparing a near-alpha type high-temperature titanium alloy foil to solve the problems in the background art in view of the deficiencies of the prior art.

[0007] To solve the above technical problems, the technical scheme adopted by the application is as follows: a rolling process for efficiently preparing a near-alpha type high-temperature titanium alloy foil, comprising the following steps:

[0008] S1, a near-alpha type high-temperature titanium alloy plate blank with a thickness of 2-5 mm is cut into a blank, 2-4 pieces are grouped, the surface is covered with a steel plate, a cladding rolling package is made by argon arc welding, and a gas inlet is arranged at both ends of the cladding rolling package;

[0009] S2, the clad rolling package is kept in a heating furnace for a holding time t1 min, and rolling is performed to obtain a blank with a thickness of 1.0±0.1 mm;

[0010] S3, the clad rolling package is kept in a heating furnace for a holding time t2 min, and rolling is performed to obtain a blank with a thickness of 0.13±0.04 mm;

[0011] S4, the blank obtained in S3 is subjected to creep correction, and the clad layer is removed to obtain a semi-finished foil, and after alkaline and acid washing, a rolled foil with a thickness of 0.08-0.15 mm is obtained;

[0012] S5, the rolled foil is placed in a vacuum furnace for vacuum annealing treatment, and a finished foil with a thickness of 0.08-0.15 mm is obtained.

[0013] Preferably, in S1, the steel plate is specifically a Q235 steel plate with a thickness of 10-25 mm, and the inner surface of the steel plate is polished before use.

[0014] Preferably, in S1, the steel plate is a clad layer, and the clad layer is lubricated with carbon powder between the clad layer and the blank and between the blanks.

[0015] Preferably, in S2, the rolling is multi-pass rolling, the total deformation amount of each pass is not less than 30%, the deformation amount of each pass is 5-20%, and the holding time t3 min between passes is returned to the furnace.

[0016] Preferably, t1=d×1.5-25~d×1.5+25 min, t3=d×1~d×2 min;

[0017] Wherein, d is the thickness of the clad rolling package, unit: mm.

[0018] Preferably, in S3, the rolling is multi-pass rolling, the total deformation amount of each pass is not more than 20%, the pass is 1-2 times, and the holding time t4 min between passes is returned to the furnace.

[0019] Preferably, t2=d×1.5-5~d×1.5+5 min, t4=d×0.5~d×1.5 min;

[0020] Wherein, d is the thickness of the clad rolling package, unit: mm.

[0021] Preferably, in S2 and S3, the holding temperature is 20-80℃ below the beta phase transformation point, the rolling method is cross rolling, and specifically, the rolling direction of each pass is perpendicular to the rolling direction of the previous pass.

[0022] As preferred, the vacuum annealing temperature in S5 is 650-750℃, the annealing time is 90-180min, and the vacuum degree is 10 -4 ~10 -3 Pa, and the furnace is cooled down.

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

[0024] 1. The present application only uses hot rolling process during rolling, and the process is short and efficient, the used package does not need to be repeatedly disassembled, and the cost is low.

[0025] 2. The present application uses cladding and stacking process to prepare near-alpha type high-temperature titanium alloy foil, which reduces the requirements for rolling equipment and avoids cracking defects caused by surface temperature drop in the hot rolling process.

[0026] 3. The rolling mode during rolling in the present application uses cross rolling, which effectively weakens the rolling texture of the finished foil.

[0027] 4. The high-temperature titanium alloy foil prepared by the present application has a thickness of 0.08-0.15mm, the thickness is accurately controllable, and the surface quality is excellent, the microstructure is equiaxed microstructure with an average grain size of 3-6μm, and the texture is weak basal texture. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is an optical microscope photo of the Ti65 alloy foil of the first embodiment of the present application;

[0029] Figure 2 is a {0001} pole figure of the Ti65 alloy foil of the first embodiment of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] Embodiment 1, the present application provides a technical solution: a rolling process for efficiently preparing near-alpha type high-temperature titanium alloy foil, specifically the preparation of near-alpha type high-temperature titanium alloy Ti65 titanium alloy foil with a thickness of 0.12mm, including the following steps:

[0032] S1. Two Ti65 titanium alloy thin plates with dimensions of 150×100×2mm are clad with Q235 steel plates with a thickness of 20mm. The inner side of the steel plate is polished, and carbon powder is added between the interfaces as a lubricant. The cladding ladle is welded by argon arc welding to obtain a cladding ladle with a thickness of 45mm. Ventilation ports are provided at both ends of the cladding ladle.

[0033] S2. After holding the cladding roll in a heating furnace at 970℃ for 60 minutes, roll it using cross rolling, i.e., the rolling direction of each rolling pass is perpendicular to the rolling direction of the previous rolling pass. Roll out a cladding roll with a thickness of 12.4 mm. The number of rolling passes is 5, the deformation per pass is 7-15%, the total deformation is 72%, and the reheating time between each rolling pass is 15-30 minutes.

[0034] S3. After holding the cladding roll in a heating furnace at 970℃ for 15 minutes, roll it in the same direction as in S2. Roll it to obtain a cladding roll with a thickness of 2.5mm. The number of rolling passes is 7, the number of passes per rolling pass is 1, the total deformation is 80%, and the reheating time between each rolling pass is 7 to 15 minutes.

[0035] S4. After creep correction, the cladding and rolling layer of the obtained cladding and rolling layer is removed to obtain a semi-finished foil. After alkaline and acid washing, a rolled foil with a thickness of 0.12 mm is obtained.

[0036] S5. Place the rolled foil into a vacuum furnace for vacuum annealing. The temperature of the vacuum furnace is 750℃, the annealing time is 90 minutes, and the vacuum degree is 10. -4 Pa, to obtain a finished foil with a thickness of 0.12 mm.

[0037] The 0.12mm thick Ti65 high-temperature titanium alloy foil prepared in this embodiment is specifically as follows: Figure 1 As shown, its microstructure is a typical equiaxed structure with an average grain size of 3–5 μm;

[0038] The texture is a weak basal texture, specifically as follows: Figure 2 As shown.

[0039] Example 2: This invention provides a technical solution: a rolling process for efficiently preparing near-α type high-temperature titanium alloy foil, specifically the preparation of a near-α type high-temperature titanium alloy Ti65 foil with a thickness of 0.10 mm, comprising the following steps:

[0040] S1, two pieces of Ti65 titanium alloy sheet with a size of 150*100*2.1mm are set as a group, wrapped with Q235 steel plate with a thickness of 20mm, the inner side of the steel plate is polished, carbon powder is added between the interfaces as a lubricant, the wrapped rolling package is welded by argon arc welding, a wrapped rolling package with a thickness of 45mm is obtained, and a gas inlet is arranged at both ends of the wrapped rolling package;

[0041] S2, the wrapped rolling package is heated in a heating furnace at a temperature of 1000℃ for 75min and then rolled, the rolling mode is cross rolling, that is, the rolling direction of each rolling pass is perpendicular to the rolling direction of the previous rolling pass, a wrapped rolling package with a thickness of 11.9mm is obtained, the number of rolling passes is 4, the deformation amount of each pass is 8-17%, the total deformation amount is 74%, and the reheating time between each rolling pass is 20-35min;

[0042] S3, the wrapped rolling package is heated in a heating furnace at a temperature of 1000℃ for 15min and then rolled, the rolling direction is the same as in S2, a wrapped rolling package with a thickness of 2.4mm is obtained, the number of rolling passes is 7, the number of passes of each rolling pass is 1, the total deformation amount is 78%, and the reheating time between each rolling pass is 5-12min;

[0043] S4, after the obtained wrapped rolling package is creep-shaped, the wrapped rolling layer is removed to obtain a semi-finished foil, and after being washed with alkali and acid, a rolled foil with a thickness of 0.10mm is obtained;

[0044] S5, the rolled foil is placed in a vacuum furnace for vacuum annealing treatment, the temperature of the vacuum furnace is 750℃, the annealing time is 120min, the vacuum degree is 10 -4 Pa, a finished foil with a thickness of 0.10mm is obtained.

[0045] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0046] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A rolling process for efficiently producing a near-alpha type high temperature titanium alloy foil, characterized by, The method comprises the following steps: The near-alpha high-temperature titanium alloy slab with a thickness of 2-5 mm is sheared into a blank, 2-4 pieces of the blank are wrapped with a steel plate to form a wrapped rolling package, the steel plate is a Q235 steel plate with a thickness of 10-25 mm, the inner surface of the steel plate is polished before use, the wrapped rolling package is provided with air vents at both ends, the steel plate is a wrapping layer, and the wrapping layer and the blanks and the blanks are lubricated with carbon powder; The wrapped rolling package is kept in a heating furnace, and is rolled in two times, the blank is obtained after rolling after keeping warm, the rolling after keeping warm is multi-pass rolling, the total deformation of each rolling pass in the first keeping warm rolling is not less than 30%, the deformation of each pass is 5-20%, the first keeping warm time t1 is min, the back-furnace keeping warm time t3 between rolling passes is min, the blank with a thickness of 1.0±0.1 mm is obtained after rolling, the keeping warm temperature is 20-80 DEG C below the beta phase transition point, the rolling mode is cross rolling, and specifically, the rolling direction of each rolling pass is perpendicular to the rolling direction of the last rolling pass; The obtained blank is removed from the clad laminated layer after creep correction, to obtain a semi-finished foil, and the rolling state foil is obtained after alkali and acid washing, and the finished foil is obtained after vacuum annealing treatment of the rolling state foil. The annealing treatment is to put the rolling state foil into a vacuum furnace for vacuum annealing treatment, the temperature is 650-750℃, the annealing time is 90-180min, the vacuum degree is 10 -4 ~10 -3 Pa, the rolling state foil has a thickness of 0.10-0.12mm after furnace cooling and alkali and acid washing, and the finished foil has a thickness of 0.10-0.12mm.

2. The rolling process for efficiently producing a near-alpha high temperature titanium alloy foil according to claim 1, characterized in that, t1=d*1.5-25~d*1.5+25min, t3=d*1~d*2min; Wherein, d is the thickness of the wrapped rolling package, and the unit is mm.

3. The rolling process for efficiently producing a near-alpha high temperature titanium alloy foil according to claim 1, characterized in that, The total deformation of each rolling pass in the second keeping warm rolling is not more than 20%, the pass is 1-2 times, the second keeping warm time t2 is min, the blank with a thickness of 0.13±0.04 mm is obtained after rolling, and the back-furnace keeping warm time t4 between rolling passes is min.

4. The rolling process for efficiently producing a near-alpha high temperature titanium alloy foil according to claim 1, characterized in that, t2=d*1.5-5~d*1.5+5min, t4=d*0.5~d*1.5min; Wherein, d is the thickness of the wrapped rolling package, and the unit is mm.

Images