Continuous annealing process of TA4 cold-rolled titanium strip coil

Abstract

The invention discloses a continuous annealing process for TA4 cold-rolled titanium strip coils, which comprises the following steps: S1, surface degreasing: degreasing TA4 cold hard coils to remove oil stains on the surfaces; s2, continuous annealing of the material coil: introducing protective gas into a continuous annealing furnace, continuously heating to 520-650 DEG C, feeding the TA4 titanium strip coil into the furnace, carrying out continuous annealing, and carrying out titanium strip coil running by a rolling machine at a set running speed and tension; and S3, the material strip is cooled, specifically, the titanium strip is cooled in the cooling section of the continuous furnace, and a titanium strip coil is wound through a winding machine. The TA4 titanium strip coil manufactured through the technological process of surface degreasing, continuous annealing and cooling is stable in tensile strength, yield strength and ductility and meets the use standard.

Description

Technical Field

[0001] The invention relates to the technical field of strip continuous annealing, in particular to a continuous annealing process for a TA4 cold-rolled titanium strip coil. Background Art

[0002] Titanium is a metal material with low density, good high-temperature strength, and excellent functions such as superconductivity, hydrogen storage, and memory. It is widely used in aerospace, national defense, petrochemical, marine development, superconductivity, nuclear power, medical materials, architectural decoration, sports equipment, and civilian fields. Titanium strip is one of the commonly used materials for the back panel of folding screen mobile phone displays. During production, the back panel is made through continuous rolling, annealing, cooling molding, slitting and other processes. The performance of the folding screen mobile phone display requires the back panel to meet mechanical properties and other parameter indicators. However, the common titanium strip continuous annealing process does not have sufficient degreasing and improper annealing parameter design, resulting in its tensile strength, yield strength, and elongation not meeting the standards. Summary of the invention

[0003] The purpose of the present invention is to provide a continuous annealing process for TA4 cold-rolled titanium coils in order to solve the problems of insufficient degreasing and improper annealing parameter design in the common TA4 titanium coil continuous annealing process, which result in the titanium coils' tensile strength, yield strength and elongation not meeting the standards.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme: a continuous annealing process of TA4 cold-rolled titanium strip coil, comprising the following steps:

[0005] S1. Surface degreasing: Degrease the TA4 cold-hardened coil to remove surface oil stains;

[0006] S2. Continuous annealing of the coil: In the continuous annealing furnace, protective gas is introduced and the temperature is continuously raised to 520-650°C. The degreased TA4 titanium strip is rolled into the furnace for continuous annealing. The coiler continuously runs the titanium strip at the set running speed and tension.

[0007] S3, strip cooling: The titanium strip is cooled in the cooling section of the continuous furnace, and the coiler coils the titanium strip.

[0008] As a further description of the above technical solution:

[0009] In step S1, the degreasing reagent is an alkaline reagent and an oily substance that shows low viscosity when in contact with the titanium strip coil, and the alkaline reagent is a sodium hydroxide solution with a volume concentration lower than 7%.

[0010] As a further description of the above technical solution:

[0011] The temperature of the degreasing agent in step S1 is 68-72°C.

[0012] As a further description of the above technical solution:

[0013] The protective gas in step S2 is high-purity argon gas with a purity not less than 99.99%.

[0014] As a further description of the above technical solution:

[0015] The tape running speed in step S2 is 3-20 m / min.

[0016] As a further description of the above technical solution:

[0017] In step S2, the tape running speed gradually decreases within a single fixed tape running distance and increases to a maximum value before the next fixed tape running distance, and the tape running speed curve is a cyclic wave curve.

[0018] As a further description of the above technical solution:

[0019] The control tension of the winding machine in steps S2 and 3 is 5-15N / mm 2 .

[0020] In summary, due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0021] 1. The TA4 titanium strip coil and the folding screen mobile phone display back panel manufactured by the process of surface degreasing, continuous annealing and strip cooling of the present invention have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0022] 2. Through the mixing of multiple components of degreasing agents and temperature design, the titanium strip coils can be fully degreased in multiple ways; the design of parameters such as continuous annealing temperature control, pressure roller material, layout position, belt speed, tension control, etc., improves the mechanical properties of the titanium strip coils such as tensile strength, yield strength, and elongation after continuous annealing and heat leveling; the titanium strip coils after continuous annealing are cooled after winding and storage, which can release the stress generated during winding and ensure its quality; the finished titanium strip coils are convenient for slitting and forming the back panel of the mobile phone display. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 The figure is a process flow chart of a continuous annealing process for a TA4 cold-rolled titanium strip coil. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0029] In the description of the embodiments of the present invention, it should be noted that the terms "upper", "inner", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0030] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] See also Figure 1 The present invention provides a technical solution: a continuous annealing process of a TA4 cold-rolled titanium strip coil, which is specifically used to make a folding screen mobile phone display back panel. The basic process solution includes the following steps:

[0032] S1. Surface degreasing: Degrease the TA4 cold-hardened coil to remove surface oil stains;

[0033] S2, continuous annealing of the material coil: protective gas is introduced into the continuous annealing furnace, and the temperature is continuously raised to 520-650°C. The degreased TA4 titanium strip is rolled into the furnace for continuous annealing; during step S2, synchronous thermal leveling of the titanium strip coil can be performed: thermal leveling of the cross section of the material strip coil is performed by the pressure rollers around the conveying path of the titanium strip coil in the continuous annealing furnace, and the winding machine continuously runs the titanium strip coil at the set running speed and tension;

[0034] S3, strip cooling: The titanium strip is cooled in the continuous furnace cooling section, and the coiler coils the titanium strip after continuous annealing. In addition, the coiled titanium strip can also be cooled by air cooling equipment around the coiler and on the material tray for winding the titanium strip.

[0035] In step S1, the degreasing reagent is an alkaline reagent and an oily substance that shows low viscosity when in contact with the titanium strip coil, and the alkaline reagent is a sodium hydroxide solution with a volume concentration of less than 7%. Through the chemical reaction of the alkaline substance and the oil stain, the oil stain is removed in multiple ways to ensure the degreasing quality of the titanium strip coil. The alkaline reagent uses a sodium hydroxide solution with a volume concentration of less than 7%. While ensuring that the alkaline substance fully reacts with the oil stain, it avoids excessive loss of the oil substance. The low viscosity of the oil substance facilitates its separation from the surface of the titanium strip coil, achieving a no-residue effect.

[0036] In step S1, the temperature of the degreasing reagent is 68-72°C, which ensures that the alkalinity, chemical reaction of oil substances, and mutual dissolution of oils completely remove the oil stains on the titanium coil, and preheats the titanium coil to avoid excessive temperature difference when it enters the continuous annealing furnace in a high-temperature environment, which may cause damage to its quality.

[0037] The protective gas in step S2 is high-purity argon gas with a purity of not less than 99.99%, which ensures the quality of continuous annealing and titanium strip coiling.

[0038] In the synchronous heat leveling treatment, the pressure roller is one or more of a silicon carbide roller or a graphite roller, so that the pressure roller has properties such as high temperature resistance and good wear resistance, ensuring its heat leveling quality for the titanium strip coil and a long service life and working time.

[0039] The tape running speed in step S2 is 3-20 m / min, and the tape running adopts a constant speed.

[0040] In addition, in order to facilitate the subsequent slitting of the titanium strip and the forming of the back panel of the folding screen mobile phone display, the tape running speed in step S2 gradually decreases within a single fixed tape running distance and increases to a maximum value before the next fixed tape running distance. The tape running speed curve is a cyclic wave curve, so that the size of the back panel and the nozzle material is obviously different, which is convenient for the subsequent material strip slitting. Among them, the fixed tape running distance parameter is designed based on the back panel size.

[0041] The control tension of the winding machine in steps S2 and 3 is 5-15N / mm 2 .

[0042] The TA4 titanium strip roll and the folding screen mobile phone display back panel manufactured in this embodiment have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0043] Embodiment 1:

[0044] On the basis of the above basic process scheme, preferably, in step S1, the volume concentration of the sodium hydroxide solution is 6%, the temperature of the degreasing agent is 68°C, the continuous annealing temperature in step S2 is 520°C, and the tension of the winding machine in step S3 is controlled to be 12N / mm 2 .

[0045] The TA4 titanium strip roll and the folding screen mobile phone display back panel manufactured in this embodiment have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0046] Embodiment 2:

[0047] On the basis of the above basic process scheme, preferably, in step S1, the volume concentration of the sodium hydroxide solution is 5%, the temperature of the degreasing agent is 70°C, the continuous annealing temperature in step S2 is 540°C, and the tension of the winding machine in step S3 is controlled to be 8N / mm 2 .

[0048] The TA4 titanium strip roll and the folding screen mobile phone display back panel manufactured in this embodiment have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0049] Embodiment three:

[0050] On the basis of the above basic process scheme, preferably, in step S1, the volume concentration of the sodium hydroxide solution is 3%, the temperature of the degreasing agent is 72°C, the continuous annealing temperature in step S2 is 580°C, and the tension of the winding machine in step S3 is controlled to be 5N / mm 2 .

[0051] The TA4 titanium strip roll and the folding screen mobile phone display back panel manufactured in this embodiment have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0052] In summary, due to the adoption of the above technical solution, the continuous annealing process of a TA4 cold-rolled titanium strip coil in this embodiment has the following beneficial effects compared with the prior art:

[0053] 1. The TA4 titanium strip coil and the folding screen mobile phone display back panel manufactured by the process of surface degreasing, continuous annealing and strip cooling of the present invention have stable mechanical properties and meet the use standards. The tensile strength can be controlled within 650-750MPa, the yield strength can be controlled within 500-650MPa, and the elongation A 50mm ≥16%.

[0054] 2. Through the mixing of multiple components of degreasing agents and temperature design, the titanium strip coils can be fully degreased in multiple ways; the design of parameters such as continuous annealing temperature control, pressure roller material, layout position, belt speed, tension control, etc., improves the mechanical properties of the titanium strip coils such as tensile strength, yield strength, and elongation after continuous annealing and heat leveling; the titanium strip coils after continuous annealing are cooled after winding and storage, which can release the stress generated during winding and ensure its quality; the finished titanium strip coils are convenient for slitting and forming the back panel of the mobile phone display.

[0055] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A continuous annealing process for TA4 cold-rolled titanium strip coil, characterized in that: The following steps are involved: S1. Surface degreasing: Degrease the TA4 cold-hardened coil to remove surface oil stains; S2. Continuous annealing of the coil: In the continuous annealing furnace, protective gas is introduced and the temperature is continuously raised to 520-650°C. The degreased TA4 titanium strip is rolled into the furnace for continuous annealing. The coiler continuously runs the titanium strip at the set running speed and tension. S3, strip cooling: The titanium strip is cooled in the cooling section of the continuous furnace, and the coiler coils the titanium strip.

2. A continuous annealing process for TA4 cold-rolled titanium strip according to claim 1, characterized in that: In step S1, the degreasing reagent is an alkaline reagent and an oily substance that shows low viscosity when in contact with the titanium strip coil, and the alkaline reagent is a sodium hydroxide solution with a volume concentration lower than 7%.

3. A continuous annealing process for TA4 cold-rolled titanium strip according to claim 2, characterized in that: The temperature of the degreasing agent in step S1 is 68-72°C.

4. A continuous annealing process for TA4 cold-rolled titanium strip according to claim 1, characterized in that: The protective gas in step S2 is high-purity argon gas with a purity not less than 99.99%.

5. The continuous annealing process of a TA4 cold-rolled titanium strip coil according to claim 1, characterized in that: The tape running speed in step S2 is 3-20 m / min.

6. A continuous annealing process for TA4 cold-rolled titanium strip according to claim 5, characterized in that: In step S2, the tape running speed gradually decreases within a single fixed tape running distance and increases to a maximum value before the next fixed tape running distance, and the tape running speed curve is a cyclic wave curve.

7. The continuous annealing process of TA4 cold-rolled titanium strip according to claim 1, characterized in that: The control tension of the winding machine in steps S2 and 3 is 5-15N / mm 2 .

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