Method for controlling head buckling and head warping of titanium plate in rough rolling process and titanium plate intermediate billet

Abstract

The invention relates to the technical field of titanium plate rolling, in particular to a method for controlling head buckling and head warping of a titanium plate in a rough rolling process and a titanium plate intermediate billet. The titanium plate intermediate blank is prepared by the method. The method comprises the steps that a titanium plate blank is heated, so that the temperature of the upper surface of the titanium plate blank is 10-20 DEG C higher than that of the lower surface of the titanium plate blank; conveying the titanium plate blank into a rough rolling process, and carrying out multi-pass rolling treatment to obtain a titanium plate intermediate blank of which the buckling head and the warping head are controlled; and according to the buckling head size condition occurring in the rolling treatment of each pass, the reduction level of the cooling water flow of the roller way during the rolling treatment of the next pass is controlled in time, or according to the warping head size condition occurring in the rolling treatment of each pass, the increase level of the cooling water flow of the roller way during the rolling treatment of the next pass is controlled in time. According to the method, rough rolling head buckling and head warping can be effectively controlled, and the surface quality and the production stability of the titanium material are improved.

Description

Technical Field

[0001] The invention relates to the technical field of titanium plate rolling, and in particular to a method for controlling buckles and warps of titanium plates in a rough rolling process and a titanium plate intermediate billet. Background Art

[0002] Titanium, with its low density, high specific strength, strong corrosion resistance, excellent high-temperature resistance, and good biocompatibility, has been widely used in aerospace, chemical equipment, medical devices, marine engineering, and sports equipment. Industrially pure titanium (such as TA1 and TA2) and low-strength titanium alloys are primarily used in the manufacture of corrosion-resistant structural components such as chemical reactors, desalination equipment, and ship fittings. Medium- and high-strength titanium alloys, such as TC4 (Ti-6Al-4V) and TB6, are the primary materials used in critical load-bearing components such as aircraft compressor blades, rocket fuel tanks, and submersible pressure hulls.

[0003] Titanium can be formed using various methods, including powder metallurgy, forging, and rolling. Rolled titanium often uses ingots produced in a vacuum consumable process. Billets obtained through forging and machining serve as raw material. Products include tubes, bars, wire, hot-rolled coils, cold-rolled coils, profiles, and sheets. Hot-rolled coils are the most widely used, and can be slit into sheets and further processed into cold-rolled coils and tubes. Therefore, studying the hot rolling process for titanium is of great significance. The hot rolling process typically involves heating, rough rolling, finish rolling, and coiling. However, during the rough rolling process, uncontrolled buckling (downward bending of the head or tail of the rolled piece during rolling) and warping (upward bending of the head or tail of the rolled piece during rolling) often occur. This can cause the head of the rolled piece to strike the equipment, resulting in scratches, or worse, rolling anomalies or even equipment damage.

[0004] Currently, the industry often uses the temperature difference between the upper and lower surfaces of the heating furnace to control the buckling and warping of the rolled piece during the rough rolling process. However, this method has a poor control effect, mainly due to the following reasons: 1) The temperature difference between the upper and lower surfaces of the rolled piece can only be indirectly adjusted by adjusting the temperature difference between the upper and lower surfaces of the heating furnace. This makes it impossible for the heating furnace to directly and accurately control the temperature difference between the upper and lower surfaces of the rolled piece, resulting in poor control of buckling and warping of the rolled piece. 2) Indirect heat transfer from the heating furnace to the rolled piece results in a slow heat transfer rate. Adjusting the temperature difference between the upper and lower surfaces of the rolled piece requires stopping the rolling mill, which interferes with normal production. 3) Since hot rolling is a continuous production, the temperature of all rollers in contact with the workpiece will affect the stability of rolling. If the rolling is stopped, the temperature of the rollers will drop, resulting in poor control of the buckling and warping of the workpiece during the rough rolling process.

[0005] In summary, it is necessary to develop a method for controlling the buckle head and warping of titanium plates in the rough rolling process and a titanium plate intermediate billet to solve the problem in the prior art that the buckle head and warping of the rolled piece are often uncontrolled in the rough rolling process. Summary of the Invention

[0006] The present invention aims to provide a method for controlling buckle head and warping head of titanium plate in the rough rolling process and a titanium plate intermediate billet. The specific technical solution is as follows: In a first aspect, the present invention provides a method for controlling buckle head and warping head of titanium plate in a rough rolling process, comprising: Step S1, heating the titanium slab so that the upper surface temperature of the titanium slab is 10-20° C. higher than the lower surface temperature; Step S2: conveying the titanium slab to a rough rolling process, and performing multiple rolling processes to obtain a titanium slab intermediate slab with controlled buckle and warp; When the buckle size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced within 20%; When the buckle size is within 100~200mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced by 10%~30%; When the buckle size is within 200~300mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 20%~40%; When the buckle size is within 300~500mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 30%~50%; When the warp size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is increased by less than 20%; When the warp size is within 100~200mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 10%~30%; When the warp size is within 200~300mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 20%~40%; When the warp size is within 300~500mm in each rolling process, the cooling water flow rate of the roller during the next rolling process is controlled to increase by 30%~50%.

[0007] Optionally, in step S2, the deformation of each rolling process is controlled to be no more than 45 mm.

[0008] Optionally, in step S2, the multi-pass rolling process includes 3 to 9 passes of rolling process.

[0009] Optionally, in step S2, the buckle head size and the lift head size are both obtained by taking real-time photos with an online camera.

[0010] Optionally, in step S1, the temperature of the titanium slab after the heating treatment is 850-1150°C.

[0011] Optionally, in step S1, the heating time used in the heat treatment is 150-350 minutes, and the heating temperature used is 850-1150°C.

[0012] Optionally, in step S1, the heating equipment used for the heat treatment includes a heating furnace; a plurality of burners are symmetrically arranged on the upper surface and the lower surface of the heating furnace; during heating, the burners in the heating furnace are heated by an extraction method.

[0013] Optionally, in step S1, the thickness of the titanium slab is less than or equal to 250 mm.

[0014] In a second aspect, the present invention provides a titanium plate intermediate billet, which is produced by the method for controlling the buckle head and the warp head of the titanium plate in the rough rolling process.

[0015] Optionally, the buckle size of the titanium plate intermediate blank is less than or equal to 100 mm, the warp size of the titanium plate intermediate blank is less than or equal to 100 mm; and the thickness of the titanium plate intermediate blank is less than or equal to 60 mm.

[0016] Optionally, when the titanium plate intermediate blank is a hot-rolled titanium strip coil intermediate blank, its thickness is less than 60 mm.

[0017] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The present invention provides a method for controlling the buckle and warping of titanium plates in the rough rolling process, which can solve the problem of uncontrolled buckle and warping of rolled pieces in the rough rolling process in the prior art. Specifically, the present invention controls the upper surface temperature of the titanium slab to be 10-20°C higher than the lower surface temperature by means of the heating treatment in step S1. Furthermore, the present invention controls the reduction level of the cooling water flow of the roller in the next rolling process in a timely manner according to the buckle size appearing in each rolling process, or controls the increase level of the cooling water flow of the roller in the next rolling process in a timely manner according to the warping size appearing in each rolling process, thereby timely increasing or decreasing the temperature of the roller in the rough rolling process, that is, increasing or decreasing the heat transfer degree of the roller to the rolled piece (i.e., the titanium slab), directly and accurately changing the temperature difference between the upper and lower surfaces of the rolled piece during the rolling process, which is beneficial to improving the fluidity of the metal on the upper and lower surfaces of the rolled piece in the rough rolling process, achieving effective control of the buckle and warping of the rough rolling, and improving the surface quality and production stability of the titanium material. In addition, the present invention can directly and accurately change the temperature difference between the upper and lower surfaces of the rolled piece during the rolling process without stopping the rolling mill, thereby greatly improving production efficiency. Furthermore, the present method has very high operability and has application value and promotion value.

[0018] (2) The buckle size of the titanium plate intermediate blank provided by the present invention is less than or equal to 100 mm, and the warp size is less than or equal to 100 mm, thereby achieving effective control of the rough rolling buckle and warp, and improving the surface quality and rolling stability of the titanium material. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0020] Example 1: A method for controlling buckle head and warping head of titanium plate in a rough rolling process, comprising: Step S1: Place a titanium slab (the thickness of the titanium slab is 195 mm, the length is 5315 mm, and the width is 1250 mm) in a heating furnace for heating treatment, so that the upper surface temperature of the titanium slab is 10-20°C higher than the lower surface temperature; multiple burners are symmetrically arranged on the upper and lower surfaces of the heating furnace; during heating, the burners in the heating furnace are heated by a pull-out method, ensuring that the minimum gas flow rate of the open burner is 12000 m³ / h and the maximum gas flow rate is 1 5000m³ / h, the specific gas flow rate is related to the temperature requirement in the heating furnace; if the required temperature in the heating furnace is high, the gas flow rate is increased; if the required temperature in the heating furnace is low, the gas flow rate is reduced; the temperature of the titanium slab after the heating treatment is 850-1150°C (specifically 1040°C); the heating time used in the heating treatment is 150-350min (specifically 210min), and the heating temperature used is 850-1150°C (specifically 1055°C); Step S2: conveying the titanium slab to a rough rolling process, and performing five rolling processes on a reversible hot rolling mill to obtain a titanium slab intermediate slab with controlled buckle and warp; When the buckle size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced within 20%; When the buckle size is within 100~200mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced by 10%~30%; When the buckle size is within 200~300mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 20%~40%; When the buckle size is within 300~500mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 30%~50%; When the warp size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is increased by less than 20%; When the warp size is within 100~200mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 10%~30%; When the warp size is within 200~300mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 20%~40%; When the warp size is within 300~500mm in each rolling process, the cooling water flow rate of the roller during the next rolling process is controlled to increase by 30%~50%.

[0021] In step S2, the absolute value of the deformation amount of each rolling process is controlled to be no greater than 45 mm.

[0022] In step S2, the buckle head size and the lift head size are both obtained by taking real-time photos with an online camera.

[0023] In the five-pass rolling process: After the first rolling process, the deformation amount is 35 mm, the warp size of the titanium slab is 230 mm, and the cooling water flow rate of the roller during the second rolling process is increased by 25%; After the second rolling process, the deformation amount is 35 mm, the warp size of the titanium slab is 60 mm, and there is no need to adjust the cooling water flow of the roller during the third rolling process; After the third rolling process, the deformation amount is 30 mm, the warp size of the titanium slab is 50 mm, and there is no need to adjust the cooling water flow of the roller during the fourth rolling process; After the fourth rolling process, the deformation amount is 25 mm, the warp size of the titanium slab is 120 mm, and the cooling water flow rate of the roller during the fifth rolling process is increased by 11.5%; After the fifth rolling process, the deformation amount is 25 mm, the thickness of the titanium plate is 45 mm, and the warp size of the titanium plate is 40 mm.

[0024] After the fifth rolling pass, the titanium plate intermediate bar was subjected to finish rolling (for details on the finish rolling process, see the Chinese invention patent application publication number 201610118108.X). Inspection of the hot-rolled coils revealed no defects due to rough rolling buckling or warping. The hot-rolled titanium coils were 5 mm thick.

[0025] Example 2: A method for controlling buckle head and warping head of titanium plate in a rough rolling process, comprising: Step S1: Place a titanium slab (the titanium slab has a thickness of 210 mm, a length of 7110 mm, and a width of 1000 mm) in a heating furnace for heating treatment, so that the upper surface temperature of the titanium slab is 10-20°C higher than the lower surface temperature; multiple burners are symmetrically arranged on the upper and lower surfaces of the heating furnace; during heating, the burners in the heating furnace are heated by a pull-out method, ensuring that the minimum gas flow rate of the open burner is 12000 m³ / h and the maximum gas flow rate is 13000m³ / h, the specific gas flow rate is related to the temperature requirement in the heating furnace; if the required temperature in the heating furnace is high, the gas flow rate is increased; if the required temperature in the heating furnace is low, the gas flow rate is reduced; the temperature of the titanium slab after the heating treatment is 850-1150°C (specifically 900°C); the heating time used in the heating treatment is 150-350min (specifically 250min), and the heating temperature used is 850-1150°C (specifically 910°C); Step S2: conveying the titanium slab to a rough rolling process, and performing seven rolling processes on a reversible hot rolling mill to obtain a titanium slab intermediate slab with controlled buckle and warp; When the buckle size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced within 20%; When the buckle size is within 100~200mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced by 10%~30%; When the buckle size is within 200~300mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 20%~40%; When the buckle size is within 300~500mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 30%~50%; When the warp size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is increased by less than 20%; When the warp size is within 100~200mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 10%~30%; When the warp size is within 200~300mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 20%~40%; When the warp size is within 300~500mm in each rolling process, the cooling water flow rate of the roller during the next rolling process is controlled to increase by 30%~50%.

[0026] In step S2, the absolute value of the deformation amount of each rolling process is controlled to be no greater than 45 mm.

[0027] In step S2, the buckle head size and the lift head size are both obtained by taking real-time photos with an online camera.

[0028] In the seven-pass rolling process: After the first rolling process, the deformation amount is 30 mm, the warp size of the titanium slab is 130 mm, and the cooling water flow rate of the roller during the second rolling process is increased by 15%; After the second rolling process, the deformation amount is 30 mm, the buckle size of the titanium slab is 20 mm, and there is no need to adjust the cooling water flow of the roller during the third rolling process; After the third rolling process, the deformation amount is 25 mm, the warp size of the titanium slab is 40 mm, and there is no need to adjust the cooling water flow of the roller during the fourth rolling process; After the fourth rolling process, the deformation amount is 25 mm, the warp size of the titanium slab is 100 mm, and the cooling water flow rate of the roller during the fifth rolling process is increased by 9%; After the fifth rolling process, the deformation is 20 mm, the buckle size of the titanium plate is 50 mm, and there is no need to adjust the cooling water flow of the roller during the fifth rolling process; After the sixth rolling process, the deformation amount is 20 mm, the warp size of the titanium slab is 120 mm, and the cooling water flow rate of the roller during the sixth rolling process is increased by 11%; After the seventh rolling process, the deformation amount is 18 mm, the thickness of the titanium plate intermediate blank is 42 mm, and the warp size of the titanium plate is 28 mm.

[0029] After the seventh rolling pass, the titanium plate intermediate bar was subjected to finish rolling (for details on the finish rolling process, see the Chinese invention publication number 201610118108.X). Inspection of the hot-rolled coils revealed no defects due to rough rolling buckling or warping. The hot-rolled titanium coils were 4.5 mm thick.

[0030] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for controlling buckle head and warping head of titanium plate in rough rolling process, characterized in that: include: Step S1, heating the titanium slab so that the upper surface temperature of the titanium slab is 10-20° C. higher than the lower surface temperature; Step S2: conveying the titanium slab to a rough rolling process, and performing multiple rolling processes to obtain a titanium slab intermediate slab with controlled buckle and warp; When the buckle size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced within 20%; When the buckle size is within 100~200mm in each rolling process, the cooling water flow of the roller in the next rolling process is controlled to be reduced by 10%~30%; When the buckle size is within 200~300mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 20%~40%; When the buckle size is within 300~500mm in each rolling process, the cooling water flow of the roller in the next rolling process is reduced by 30%~50%; When the warp size is within 100mm in each rolling process, the cooling water flow of the roller in the next rolling process is increased by less than 20%; When the warp size is within 100~200mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 10%~30%; When the warp size is within 200~300mm in each rolling process, the cooling water flow rate of the roller in the next rolling process is increased by 20%~40%; When the warp size is within 300~500mm in each rolling process, the cooling water flow rate of the roller during the next rolling process is controlled to increase by 30%~50%.

2. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In step S2, the deformation of each rolling process is controlled to be no greater than 45 mm.

3. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In the step S2, the multi-pass rolling process includes 3 to 9 passes of rolling process.

4. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In step S2, the buckle head size and the lift head size are both obtained by taking real-time photos with an online camera.

5. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In the step S1, the temperature of the titanium slab after the heating treatment is 850-1150°C.

6. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In the step S1, the heating time used in the heating treatment is 150-350 minutes, and the heating temperature used is 850-1150°C.

7. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In step S1, the heating equipment used for the heating treatment includes a heating furnace; a plurality of burners are symmetrically arranged on the upper surface and the lower surface of the heating furnace; during heating, the burners in the heating furnace are heated by a thinning method.

8. The method for controlling buckle head and warping head of titanium plate in rough rolling process according to claim 1, characterized in that: In step S1, the thickness of the titanium slab is less than or equal to 250 mm.

9. A titanium plate intermediate blank, characterized in that: The titanium plate is manufactured by the method for controlling the buckle head and the warp head of the titanium plate in the rough rolling process according to any one of claims 1 to 8.

10. The titanium plate intermediate blank according to claim 9, characterized in that: The buckle size of the titanium plate intermediate blank is less than or equal to 100 mm, the warp size of the titanium plate intermediate blank is less than or equal to 100 mm; the thickness of the titanium plate intermediate blank is less than or equal to 60 mm.