Titanium steel composite plate and preparation method thereof

Abstract

The invention provides a titanium steel composite plate and a preparation method thereof. The titanium-steel composite plate comprises a titanium composite plate and a steel base body with a titanium layer on the surface which are arranged in a stacked mode. The uniform and compact titanium layer is formed on the surface of the steel substrate, a good interface condition is provided for combination of the titanium clad plate and the steel substrate, and a high-strength and high-stability combination interface is formed between the titanium layer and the steel substrate in combination with the high-temperature and high-pressure effect in the subsequent rolling process; and therefore, good combination between the steel substrate and the titanium compound plate is ensured. Meanwhile, the titanium layer can serve as a transition layer, direct chemical reaction between the titanium compound plate and the steel substrate in the high-temperature rolling process is hindered to a certain extent, generation of brittle compounds is reduced, and therefore the performance of a bonding interface is protected.

Description

Technical Field

[0001] The invention belongs to the field of metal material processing, and particularly relates to a titanium steel composite plate and a preparation method thereof. Background Art

[0002] In the field of metal material processing, titanium steel composite plates have broad application prospects in the chemical, petroleum, aerospace and other industries because they combine the excellent corrosion resistance of titanium with the high strength and low cost of steel. However, traditional titanium steel composite plate preparation methods, such as multi-pass hot rolling or explosive composite methods, have problems such as complex process flow, high energy consumption, low production efficiency and insufficient interface bonding strength. In particular, for the large-scale, high-quality production of titanium steel composite plates, a more efficient and economical preparation technology is urgently needed.

[0003] In recent years, hot rolling single-pass forming technology has shown great potential in the field of metal composite material preparation. This technology optimizes the rolling process parameters so that the materials can be well combined in a single pass through the rolling mill, thereby simplifying the preparation process and improving production efficiency. For titanium steel composite plates, hot rolling single-pass forming technology is expected to solve many shortcomings in traditional preparation methods and achieve efficient and high-quality composite plate production. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a titanium steel composite plate and a preparation method thereof. The titanium steel composite plate has excellent interface bonding strength and comprehensive performance.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a titanium-steel composite plate, which comprises a stacked titanium composite plate and a steel substrate having a titanium layer on the surface.

[0007] Preferably, the thickness of the titanium layer is 0.01-0.5 mm.

[0008] Preferably, the steel substrate is carbon steel or stainless steel, and its thickness is 0.5-8 mm.

[0009] Preferably, the surface roughness Ra of the steel substrate is 0.8-3.2.

[0010] Preferably, the titanium composite plate is made of pure titanium TA1 or pure titanium TA2, and its thickness is 0.1-8 mm.

[0011] Preferably, the surface roughness Ra of the titanium composite plate is 0.8-3.2.

[0012] In a second aspect, the present invention provides a method for preparing the titanium steel composite plate, comprising the following steps:

[0013] After the titanium composite plate and the steel substrate with a titanium layer on the surface are pressed, the pressed plate is rolled and heat treated to obtain the titanium steel composite plate.

[0014] Preferably, the titanium layer is formed by plasma titanium diffusion.

[0015] Preferably, the plasma titanium diffusion method is carried out in an inert atmosphere, and the process parameters are set as follows: the gas pressure in the furnace is 30~90 Pa, the processing temperature is 500~700℃, the holding time is 3~5 h, the cathode voltage is 500~700 V, and the source voltage is 800~1000 V.

[0016] Preferably, the titanium layer is formed by a solid powder / paste titanium infiltration method, the steps being:

[0017] After the titanium infiltration agent is applied to the surface of the steel substrate, a titanium layer is formed after the temperature is raised in a closed environment.

[0018] Preferably, the titanium infiltrating agent comprises a titanium source, a filler and a catalyst.

[0019] Preferably, the titanium source is selected from metallic titanium powder or titanium compound; the filler is selected from powdered Al2O3 or SiO2, and the catalyst is selected from ammonia halide.

[0020] Preferably, the rolling pass is a single pass, the rolling temperature is 850-1000° C., the rolling time is 2-5 min; and the rolling deformation is 25-60%.

[0021] Preferably, the rolling passes are 5 to 7 passes.

[0022] Preferably, the rolling temperature is 800-1000° C., and the deformation in each rolling pass is 15%-22%.

[0023] Preferably, the temperature of the heat treatment is 600°C to 900°C.

[0024] Preferably, the heat treatment is performed under the protection of an inert atmosphere.

[0025] In a second aspect, the present invention provides a titanium steel composite plate prepared by the above-mentioned preparation method.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides a titanium-steel composite plate, which includes a stacked titanium composite plate and a steel substrate with a titanium layer on the surface. The present invention provides good interface conditions for the combination of the titanium composite plate and the steel substrate by forming a uniform and dense titanium layer on the surface of the steel substrate, and combines the high temperature and high pressure in the subsequent rolling process to form a high-strength and high-stability bonding interface between the titanium layer and the steel substrate, thereby ensuring a good bonding between the steel substrate and the titanium composite plate. At the same time, the titanium layer can serve as a transition layer, which to a certain extent hinders the direct chemical reaction between the titanium composite plate and the steel substrate during the high-temperature rolling process, reduces the generation of brittle compounds, and thus protects the performance of the bonding interface.

[0028] In addition, the prior art generally requires the addition of an additional intermediate layer or the use of expensive materials to enhance the interface bonding, which not only increases the production cost, but also may introduce new performance instability factors. The titanium layer formed by the present invention effectively reduces the use of the intermediate layer and reduces the production cost. Moreover, since the titanium layer does not introduce additional metal, the formation of harmful intermetallic compounds in the subsequent rolling process can be effectively avoided, thereby ensuring the high performance of the titanium steel composite plate.

[0029] After testing, the titanium-steel composite plate provided by the present invention has a tensile strength of more than 500 MPa, a shear strength of more than 180 MPa, and a peel strength of more than 40 N / mm, so that the bonding interface is tight and defect-free, and the titanium-steel composite plate also has excellent corrosion resistance, mechanical properties, processing properties and weldability. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with 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.

[0031] Titanium-steel composite plates are widely used in many industrial fields because they combine the corrosion resistance of titanium and the strength of steel. The traditional rolling preparation method of titanium-steel composite plates often requires adding one or more intermediate layers (such as stainless steel, pure iron, nickel foil, etc.) between the titanium plate and the steel plate to slow down the element diffusion between titanium and steel and avoid the formation of harmful intermetallic compounds, thereby ensuring the bonding strength and performance of the composite plate. However, the addition of the intermediate layer not only increases the complexity of the preparation process, but may also lead to increased costs and additional defects at the interface.

[0032] Based on this, the present invention provides a titanium-steel composite plate without an intermediate layer, which comprises a stacked titanium composite plate and a steel substrate with a titanium layer on the surface.

[0033] In the present invention, by forming a uniform and dense titanium layer on the surface of the steel substrate, a good bond between the steel substrate and the titanium composite plate can be ensured, and the formation of harmful intermetallic compounds during the subsequent rolling process can be avoided. In some embodiments of the present invention, the thickness of the titanium layer is 0.01-0.5 mm, preferably 0.01-0.3 mm, and more preferably 0.05 mm.

[0034] In the present invention, the steel substrate is carbon steel or stainless steel, and the type of the carbon steel or stainless steel is not particularly limited, and can be any type known to those skilled in the art. Generally, the thickness of the steel substrate is controlled to be 0.5 to 8 mm, preferably 6 to 8 mm, and more preferably 8 mm.

[0035] In some preferred embodiments of the present invention, the surface of the steel substrate is pretreated by thorough cleaning, degreasing, and rust removal to ensure that its surface is clean and free of impurities, and its surface roughness Ra is controlled within 0.8-3.2, preferably Ra is 1.2-3.2, to improve its bonding strength with the titanium composite plate.

[0036] In the present invention, the material of the titanium composite plate is pure titanium TA1 or pure titanium TA2, and the thickness thereof is 0.1-8 mm, preferably 0.1-2 mm, and more preferably 1 mm.

[0037] In some preferred embodiments of the present invention, the titanium composite plate is subjected to necessary surface cleaning and pretreatment to remove surface oxides and impurities and improve the bonding strength with the steel substrate having a titanium layer on the surface. The surface roughness of the titanium composite plate is also required to be controlled within Ra 0.8-3.2.

[0038] The present invention also provides a method for preparing the titanium steel composite plate, comprising the following steps:

[0039] After the titanium composite plate and the steel substrate with a titanium layer on the surface are pressed, the pressed plate is rolled and heat treated to obtain the titanium steel composite plate.

[0040] In the present invention, the titanium layer in the steel substrate having a titanium layer on the surface can be formed by plasma titanium infiltration, solid powder / paste infiltration of metal (eg, Ti) and the like.

[0041] Exemplarily, the plasma titanium diffusing process parameters are: an inert gas, such as Ar gas, is introduced into the plasma titanium diffusing equipment as a protective gas, the gas pressure in the furnace is controlled at 30~90 Pa, preferably 60 Pa, the treatment temperature is 500~700°C, preferably 580°C; the holding time is 3~5 h, preferably 4 h; the cathode voltage is 500~700 V, preferably 580 V; the source voltage is 800~1000 V, preferably 850 V.

[0042] The solid powder / paste titaniumization process is: coating the titaniumization agent on the surface of the steel substrate, then placing it in a high temperature (800-950°C, preferably 920°C) sealed container and keeping it warm (6-16 h, preferably 8 h), the titaniumization agent includes a titanium source, a filler and a catalyst, the titanium source is a metal titanium powder or a titanium compound, the filler is the filler selected from powdered Al2O3 or SiO2, and the catalyst is selected from halogenated ammonia such as (ammonia chloride, ammonium fluoride). In the present invention, in the titaniumization agent, the mass fraction of the titanium source is between 5 and 30% (can be 5%, 10%, 15%, 20%, 25%, 30%, etc.), the mass fraction of the filler is between 30 and 70% (can be 30%, 40%, 50%, 60%, 70%, etc.), the mass fraction of the catalyst is between 2 and 10% (can be 2%, 5%, 8%, 10%, etc.), and the mass ratio of the titanium source, the filler and the catalyst is preferably 12:7:1.

[0043] According to the present invention, after obtaining the steel substrate with the titanium layer on the surface, the titanium composite plate and the steel substrate with the titanium layer on the surface are pressed. The pressing is preferably: the steel substrate with the titanium layer on the surface and the titanium composite plate are directly stacked and arranged without adding an intermediate layer. Pre-pressing treatment is performed during the stacking process to eliminate interlayer gaps and improve the density of the titanium steel composite plate.

[0044] After the pressing is completed, according to the present invention, the obtained plate is sent to a rolling mill for composite rolling. The rolling can be performed in a single pass or multiple passes.

[0045] It should be noted that the appropriate rolling temperature can ensure that titanium and steel have good plasticity and deformation ability during the rolling process, and promote the diffusion and metallurgical bonding between elements. If the rolling temperature is too low, the plasticity of the material decreases, and the deformation resistance increases, which may lead to problems such as difficulty in rolling and poor interface bonding; if the rolling temperature is too high, although the plasticity of the material increases, it may also lead to problems such as overburning, increased oxidation, and the formation of harmful intermetallic compounds at the interface. Therefore, it is important to control the rolling temperature within an appropriate range to obtain high-quality titanium-steel composite plates.

[0046] In addition, the amount of deformation will directly affect the density of the composite plate, the interface bonding strength and the final performance of the plate. Appropriate deformation can promote element diffusion and metallurgical bonding between the titanium layer and the steel matrix, and improve the interface bonding strength; at the same time, deformation can also eliminate interlayer gaps and improve the density of the composite plate. However, excessive deformation may cause excessive residual stress and cracks in the material, which will reduce the performance of the composite plate. Therefore, the deformation needs to be reasonably controlled during the rolling process.

[0047] In summary, in some embodiments of the present invention, in a single-pass rolling process, the rolling temperature is controlled at 850-1000°C, preferably 900°C; the rolling deformation is controlled at 25%-60%, preferably 50%. The present invention adopts a hot rolling single-pass forming technology, which can significantly shorten the production cycle, reduce production costs, and improve production efficiency.

[0048] Compared with single-pass rolling, multi-pass rolling can significantly refine the grain structure of the material, improve the internal density of the material, effectively reduce defects, and greatly enhance the overall mechanical properties and durability of the material, while optimizing the microstructure and surface quality of the material through repeated extrusion and stretching. Therefore, in some embodiments of the present invention, it is specifically 5 to 7 passes, such as 5 passes, 6 passes or 7 passes. The rolling temperature is 800 to 1000°C, which can be 800°C, 820°C, 850°C, 870°C, 900°C, 920°C, 950°C, 970°C or 1000°C, etc., preferably 920°C; the deformation of each rolling pass is 15 to 22%, which can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, etc., preferably 15%.

[0049] After rolling, according to the present invention, the obtained plate is subjected to heat treatment, that is, annealing. In the present invention, the heat treatment is carried out under the protection of an inert atmosphere, and the temperature of the heat treatment is 600°C to 900°C, such as 600°C, 650°C, 70°C, 750°C, 800°C, 850°C or 900°C, etc., preferably 600°C; the time of the heat treatment is 12 to 24 h, such as 12 h, 14 h, 16 h, 18 h, 20 h, 22 h or 24 h, etc., preferably 12 h. After the heat treatment is completed, generally, the plate is cooled with the furnace under the protection of the atmosphere, and finally a titanium steel composite plate is obtained.

[0050] In summary, in some specific embodiments of the present invention, the method for preparing the titanium steel composite plate comprises the following steps:

[0051] S1: Surface treatment of steel substrate: Select steel plate made of carbon steel or stainless steel with a thickness of 0.5~8mm, and perform pretreatment such as thorough cleaning, degreasing, and rust removal on the surface to ensure that the surface is clean and free of impurities, and the surface roughness is controlled between Ra 0.8 and Ra 3.2;

[0052] S2: Titanium layer formation treatment: plasma titanium infiltration, solid powder / paste metal infiltration and other methods are used to form a uniform and dense titanium layer on the surface of the steel substrate. The thickness of the titanium infiltration layer is controlled between 0.01 and 0.5 mm;

[0053] S3: Titanium plate preparation: Select titanium plates with appropriate thickness and quality as composite layer materials, and perform necessary surface cleaning and pretreatment to remove surface oxides and impurities and improve the bonding strength with the titanium-infiltrated steel matrix. The material of the titanium composite plate is pure titanium TA1, TA2, with a thickness specification of 0.1~8 mm, and the surface roughness is also required to be controlled between Ra 0.8 and Ra 3.2;

[0054] S4: Pressing: The titanium-infiltrated steel substrate and the titanium composite plate are directly stacked without adding an intermediate layer;

[0055] S5: rolling: the pressed plate is sent to a rolling mill for composite rolling. During the rolling process, the rolling temperature is controlled between 850 and 1000°C, the hot rolling is performed once, and the rolling deformation is controlled between 25 and 60%;

[0056] or

[0057] Rolling: The pressed plate is sent to the rolling mill for composite rolling. During the rolling process, the rolling temperature is controlled between 800 and 1000°C, the rolling passes are 5 to 7, and the rolling deformation of each pass is controlled between 15 and 22%;

[0058] S6: Cooling to obtain a titanium steel composite plate: After rolling, the plate is annealed at 600-900°C, and the annealed titanium steel composite plate is cooled to room temperature at an appropriate cooling rate to obtain a final product.

[0059] In summary, the preparation method of the titanium-steel composite plate provided by the present invention realizes direct composite rolling of the titanium composite plate and the steel substrate without adding an intermediate layer, simplifies the process flow, and reduces costs. At the same time, the titanium layer can serve as a transition layer to hinder the direct chemical reaction between the titanium composite plate and the steel substrate during high-temperature rolling to a certain extent, reduce the generation of brittle compounds, and thus protect the performance of the bonding interface.

[0060] In addition, the preparation method is simple, convenient, easy to implement, and conducive to large-scale production.

[0061] In order to further illustrate the present invention, the following examples are provided for detailed description. The experimental raw materials used in the following examples of the present invention are all common commercially available products.

[0062] The mechanical properties involved in the following embodiments were tested by shear test and tensile test of titanium-steel composite plate according to GB / T 8547-2019 and peel test according to ASTM D 903-1998 "Test method for peeling or peel strength of adhesives", and the corrosion resistance was tested by salt spray test according to GB / T 10125-2021.

[0063] Example 1

[0064] In this embodiment, 4 mm thick Q235 carbon steel is selected as the steel matrix. After thorough cleaning, degreasing, rust removal and other pretreatments, the surface roughness reaches Ra 1.6. Subsequently, plasma titanium diffusion technology is used, and the furnace is kept warm for 4 h at an air pressure of 60 Pa and a temperature of 650°C, with a cathode voltage of 600 V and a source voltage of 900 V, and a uniform titanium layer of about 0.02 mm thick is successfully formed on the surface of the steel matrix. A 0.3 mm thick TA2 pure titanium plate is selected as the composite layer, and the laminate is pre-pressed after the same pretreatment. The laminated composite plate is sent to the rolling mill and hot rolled at 980°C for one composite rolling, and the deformation is set to 40%. After rolling, the composite plate is annealed at a temperature of 700°C and cooled to room temperature with the furnace under atmosphere protection.

[0065] The titanium-steel composite plate prepared in this embodiment has a tensile strength of 560 MPa, a shear strength of 280 MPa, and a peel strength of 50 N / mm, meeting high performance requirements.

[0066] Example 2

[0067] In this embodiment, 6 mm thick A36 carbon steel is used as the steel substrate. After surface pretreatment, the solid powder titaniumization method is used to coat the surface of the steel substrate with titanium metal powder and Al2O3 as fillers (the amounts of each are 60%, 35%, and 5% of the total mass of the titaniumization agent, respectively), and put it into a 900℃ high-temperature sealed container for 12 hours to successfully form a titanium layer of about 0.03 mm thick. A 0.5 mm thick TA1 pure titanium plate is selected as the composite layer, and the necessary pretreatment is performed before the laminate is pre-pressed. The laminated composite plate is sent to the rolling mill and hot rolled at 995℃ for one pass of composite rolling, and the deformation is controlled at 55%. After rolling, annealing treatment is carried out at a temperature of 800℃, and the furnace is cooled under atmosphere protection.

[0068] The titanium steel composite plate prepared in this embodiment has a tight interface and significantly improved corrosion resistance. There is no sign of rust within 72 hours under the salt spray test. The tensile strength reaches 540 MPa, the shear strength reaches 220 MPa, and the peel strength reaches 45 N / mm.

[0069] Example 3

[0070] This embodiment uses 3 mm thick 304 stainless steel as the steel matrix, and forms a 0.03 mm thick titanium layer after plasma titanium treatment. A 0.25 mm thick TA2 pure titanium plate is selected as the composite material, and the laminate is pre-pressed after surface cleaning and pretreatment. The laminated composite plate is sent to the rolling mill, and hot rolling is performed at a precisely controlled rolling temperature of 990°C, and the rolling deformation is set to 35%. After rolling, annealing treatment is performed to optimize material properties. The annealing temperature is 750°C, and the furnace is cooled under atmosphere protection.

[0071] The titanium-stainless steel composite plate prepared in this embodiment has a tensile strength of 580 MPa, a shear strength of 300 MPa, and a peel strength of 55 N / mm, showing excellent comprehensive performance.

[0072] Example 4

[0073] In this embodiment, a titanium-steel composite plate is prepared by plasma titanium infiltration method. A 3 mm thick Q235 carbon steel is selected as the substrate. After thorough cleaning, degreasing and rust removal, the surface roughness is controlled at Ra 1.6. In the plasma titanium infiltration equipment, Ar gas is used as the protective gas, the gas pressure in the furnace is controlled to be 60 Pa, the treatment temperature is 650°C, the temperature is kept for 4 h, the cathode voltage is 600 V, and the source voltage is 900 V, forming a uniform titanium layer of about 0.05 mm thick. Subsequently, a 0.5 mm thick TA2 pure titanium plate is selected, which is directly laminated and pre-pressed with the titanium-infiltrated steel substrate after cleaning to eliminate the interlayer gap. The laminated plate is composite rolled at 900°C for a total of 6 passes, with a deformation of about 15% in each pass, and finally heat treated at 750°C. After cooling with the furnace, a titanium-steel composite plate is obtained.

[0074] The composite board prepared in this embodiment has a tensile strength of 500 MPa, a shear strength of more than 190 MPa, a peel strength of more than 45 N / mm, and a tight bonding interface without defects.

[0075] Example 5

[0076] In this embodiment, a titanium-steel composite plate is prepared by a solid powder / paste titanium infiltration process. A 5 mm thick No. 45 steel is selected as the substrate, and the surface roughness is controlled at Ra 2.5 after pretreatment. A titanium infiltration agent containing metallic titanium powder is coated on the surface of the substrate, and an Al2O3 filler and an ammonium fluoride catalyst are added (the amounts of each are 60%, 35%, and 5% of the total mass of the titanium infiltration agent, respectively), and placed in a 980°C high-temperature sealed container for 12 h to form a titanium layer of about 0.01 mm thick. A 1 mm thick TA1 pure titanium plate is selected, and after the same cleaning and pretreatment, it is directly laminated and pre-pressed with the titanium infiltration steel substrate. The composite plate is composite rolled at 850°C for a total of 5 passes, and the deformation of each pass is controlled at 18%. Finally, a heat treatment at 800°C is performed and the furnace is cooled to obtain a titanium-steel composite plate. The composite plate prepared in this example has a tensile strength of not less than 480 MPa, a peel strength of more than 40 N / mm, a shear strength of 180 MPa, and a good metallurgical bonding at the bonding interface without cracks or pores.

[0077] Example 6

[0078] This embodiment uses solid powder titanium infiltration method to prepare titanium steel composite plate. The steel substrate is 6 mm thick Q345 carbon steel. After pretreatment, the surface roughness is Ra 2.0. The surface is coated with titanium powder, SiO2 filler and ammonium fluoride catalyst containing titanium powder, SiO2 filler and titanium infiltration agent (the amount of each is 60%, 35% and 5% of the total mass of the titanium infiltration agent, respectively). It is kept in a 980℃ high-temperature furnace for 10 hours to form a 0.1 mm thick titanium layer. Then, the 1 mm thick TA2 titanium plate and the titanium infiltration steel substrate are laminated and pre-pressed, and hot rolled at 850℃ for 5 times, with a deformation of 20% per time. The heat treatment temperature is 750℃, and the composite plate is obtained after cooling with the furnace. The composite plate prepared in this example has a tensile strength of 500 MPa, a shear strength of 200 MPa, a peel strength of 42 N / mm, and a tight bond.

[0079] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A titanium steel composite plate, characterized in that: The invention comprises stacked titanium composite plates and a steel substrate with a titanium layer on the surface.

2. The titanium steel composite plate according to claim 1, characterized in that: The thickness of the titanium layer is 0.01-0.5 mm.

3. The titanium steel composite plate according to claim 1 or 2, characterized in that: The steel substrate is carbon steel or stainless steel, and its thickness is 0.5-8 mm; The surface roughness Ra of the steel substrate is 0.8-3.

2.

4. The preparation method according to any one of claims 1 to 3, characterized in that The titanium composite plate is made of pure titanium TA1 or pure titanium TA2, and its thickness is 0.1-8 mm; The surface roughness Ra of the titanium composite plate is 0.8-3.

2.

5. A method for preparing a titanium steel composite plate according to any one of claims 1 to 4, characterized in that: The following steps are involved: After the titanium composite plate and the steel substrate with a titanium layer on the surface are pressed, the pressed plate is rolled and heat treated to obtain the titanium steel composite plate.

6. The preparation method according to claim 5, characterized in that: The titanium layer is formed by a plasma titanium diffusion method; The plasma titanium diffusion method is carried out in an inert atmosphere, and the process parameters are set as follows: the gas pressure in the furnace is 30~90 Pa, the treatment temperature is 500~700℃, the holding time is 3~5 h, the cathode voltage is 500~700 V, and the source voltage is 800~1000 V.

7. The preparation method according to claim 5, characterized in that: The titanium layer is formed by a solid powder / paste titanium infiltration method, the steps are: After the titanium infiltration agent is applied to the surface of the steel substrate, a titanium layer is formed after the temperature is raised in a closed environment; The titanium infiltrating agent comprises a titanium source, a filler and a catalyst; The titanium source is selected from metallic titanium powder or titanium compound; the filler is selected from powdered Al2O3 or SiO2; and the catalyst is selected from ammonia halide.

8. The preparation method according to any one of claims 5 to 7, characterized in that The rolling process is a single process, the rolling temperature is 850-1000°C, and the rolling time is 2-5 min; The rolling deformation is 25-60%.

9. The preparation method according to any one of claims 5 to 7, characterized in that The rolling passes are 5 to 7 passes; The rolling temperature is 800-1000° C., and the deformation amount of each rolling pass is 15%-22%.

10. The preparation method according to any one of claims 6 to 9, characterized in that The temperature of the heat treatment is 600°C to 900°C; The heat treatment is carried out under the protection of an inert atmosphere.