Preparation method of titanium-steel composite plate and titanium-steel composite plate

Abstract

The invention discloses a preparation method of a titanium-steel composite plate and the titanium-steel composite plate, and belongs to the technical field of metal composite material preparation. The preparation method of the titanium-steel composite plate comprises the following steps: (1) carrying out titanizing treatment on the surface of a pretreated steel substrate to form a titanizing layer, so as to obtain a titanized steel substrate; (2) laminating the titanized steel substrate and the pure titanium plate, pre-pressing, and sequentially carrying out double-pass composite rolling and heat treatment to obtain a titanium steel composite plate; wherein asynchronous isothermal rolling is adopted for the first pass of double-pass composite rolling, and isothermal symmetric rolling is adopted for the second pass of double-pass composite rolling. The preparation method is simple, efficient and low in cost, a uniform and compact titanium layer is formed on the surface of the steel substrate through titanizing treatment, the binding force between the pure titanium plate and the steel substrate is enhanced, and generation of harmful metal compounds is avoided. Meanwhile, the composite rolling technology combining asynchronous isothermal rolling and isothermal symmetric rolling is adopted, and the internal organization structure and performance of the titanium steel composite plate are effectively improved by regulating and controlling rolling parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of metal composite material preparation, in particular to a preparation method of a titanium-steel composite plate and the titanium-steel composite plate. Background Art

[0002] Titanium and its alloys, due to their high specific strength, excellent corrosion resistance, and good biocompatibility, hold broad application prospects in fields such as chemical engineering, marine engineering, and medical devices. However, the high cost of pure titanium has limited its widespread adoption in large-scale industrial applications. To reduce costs while retaining titanium's excellent properties, titanium-steel clad plates have emerged.

[0003] Traditional titanium steel composite plate preparation processes include explosive composite method, rolling composite method, intermediate layer auxiliary method, etc.

[0004] The explosive bonding method involves placing titanium and steel plates at intervals and utilizing the high pressure and high-speed collision generated by the explosive explosion to achieve instant cold bonding. However, its disadvantages include significant environmental pollution, high energy consumption, low yield rates, and the presence of weld seam issues.

[0005] The rolling composite method is mainly a direct rolling method, which is to directly combine titanium plates and steel plates, and roll them at high temperatures through large-tonnage rolling mills. The large deformation is used to break the brittle phase at the interface and improve the bonding strength. However, it is suitable for the production of large-size plates and requires high rolling force (>9000t) and precise temperature control.

[0006] Intermediate layer-assisted methods include composite intermediate layer design and isolation layer methods. The composite intermediate layer design method involves adding metal foils such as nickel, chromium, and vanadium to the titanium-steel interface, which often forms harmful metal compounds. The isolation layer method involves adding fiberglass isolation cloth between the cladding layer (such as ordinary carbon steel) and the titanium / steel layer to prevent oxidation during rolling and optimize interface bonding through vacuum extraction, but this method has high production costs.

[0007] Therefore, it is particularly important to develop a preparation process that is efficient, economical and can ensure the quality of composite panels. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing a titanium-steel composite plate and a titanium-steel composite plate. The preparation method is simple, efficient, and low in cost, and the prepared titanium-steel composite plate has excellent mechanical properties.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] The present invention provides a method for preparing a titanium-steel composite plate, comprising the following steps:

[0011] (1) forming a titanium-infiltrated layer on the surface of the pretreated steel substrate by titanium infiltration treatment to obtain a titanium-infiltrated steel substrate;

[0012] (2) Stack the titanium-permeated steel substrate and the pure titanium plate, pre-press them, and then successively perform double-pass composite rolling and heat treatment to obtain a titanium-steel composite plate;

[0013] Among them, the first pass of the double-pass composite rolling adopts asynchronous isothermal rolling, and the second pass adopts isothermal symmetric rolling.

[0014] In the above preparation method, the titanium-permeated layer serves as an interfacial transition layer, enhancing the bonding force between the pure titanium plate and the steel substrate and reducing the formation of harmful metal compounds during subsequent double-pass composite rolling.

[0015] The thickness of the titanium-permeated layer affects the bonding strength between the pure titanium plate and the steel substrate, and is also related to the overall performance and service life of the titanium-steel composite plate.

[0016] The titanium-permeated layer in step (1) of the present invention is uniform and dense. Compared with the conventional method of adding other metal intermediate layers, it can better coordinate the deformation of the titanium-steel composite plate.

[0017] Preferably in the present invention, the thickness of the titanium-permeated layer is 0.05 - 0.5 mm; more preferably 0.1 - 0.3 mm. In some specific embodiments of the present invention, it is preferably 0.1 mm, 0.2 mm or 0.3 mm.

[0018] The present invention uses the addition of a titanium-permeated layer as a transition layer between the pure titanium plate and the steel substrate, which can effectively relieve the thermal stress, residual stress and tissue stress between the two materials. The titanium-permeated layer can also inhibit the formation of harmful intermetallic compounds as an intermediate layer.

[0019] The method of the titanium permeation treatment includes but is not limited to plasma titanium permeation method, solid powder / paste metal permeation method, laser cladding titanium permeation method or gas phase titanium permeation method, etc.

[0020] Preferably in the present invention, the method of the titanium permeation treatment is selected from the plasma titanium permeation method or the solid powder / paste metal permeation method.

[0021] The plasma titanium permeation method includes the following steps:

[0022] Introduce Ar gas into the plasma metal permeation equipment as a protective gas, control the furnace pressure at 30 - 90 Pa, the temperature at 500 °C - 700 °C, and keep it warm for 3 - 5 h; the cathode voltage is 500 - 700 V, and the source voltage is 800 - 1000 V to form a uniform titanium-permeated layer. Introduce Ar gas into the plasma metal permeation equipment as a protective gas;

[0023] Control the furnace pressure at 30 - 90 Pa;

[0024] The furnace temperature is 500 °C - 700 °C, and the heat preservation time is 3 - 5 h;

[0025] The cathode voltage is 500 - 700V, and the source voltage is 800 - 1000V.

[0026] The solid powder / paste metal penetration method includes the following steps:

[0027] Coat the titanium penetration agent, filler, and catalyst on the surface of the pre-treated steel substrate, and then place it in a high-temperature sealed container and keep it warm.

[0028] The temperature of the high-temperature sealed container is preferably 950°C - 1000°C;

[0029] The holding time is preferably 6 - 16h.

[0030] The titanium penetration agent is selected from metallic titanium powder or titanium-containing compounds;

[0031] The filler is selected from powdered Al2O3 or powdered SiO2;

[0032] The catalyst is selected from ammonium halides, such as ammonium chloride, ammonium fluoride, etc.

[0033] Preferably in the present invention, the speed ratio of the upper and lower rolls in the asynchronous isothermal rolling is 1.1 - 1.4, and more preferably 1.2.

[0034] Preferably, the rolling speed in the asynchronous isothermal rolling is 0.628 - 1.2m / s; more preferably 0.8 - 1.2m / s; further preferably 0.8m / s, 1.0m / s, or 1.2m / s. [[ID=۳۰]]

[0035] Preferably, the deformation amount in the asynchronous isothermal rolling is controlled within 35%; more preferably 35%.

[0036] Preferably in the present invention, the annealing treatment temperature in the asynchronous isothermal rolling is 550°C - 850°C; more preferably 650°C - 750°C. In some specific embodiments of the present invention, it is preferably 700°C or 650°C.

[0037] Preferably, the annealing treatment time is 1 - 4h.

[0038] The above annealing eliminates stress and promotes the microstructure homogenization of the titanium-steel composite plate.

[0039] After annealing, the shape and properties of the titanium-steel composite plate are further adjusted by controlling the deformation amount of the second pass.

[0040] Preferably in the present invention, the deformation amount in the isothermal symmetric rolling is controlled within 18% - 25%; more preferably 20% - 23%. In some specific embodiments of the present invention, it is preferably 20% or 22%.

[0041] Preferably, in the step (2), the heat treatment temperature is 600°C - 900°C; more preferably 600°C - 750°C. In some specific embodiments of the present invention, it is preferably 600°C, 680°C or 720°C.

[0042] Preferably, the atmosphere during the heat treatment is a vacuum or an argon protection atmosphere; more preferably argon.

[0043] After the above heat treatment, post-treatment such as cooling is also included, and cooling to room temperature gives the titanium-steel composite plate.

[0044] In the above preparation method, the lamination and pre-pressing in the step (2) are to eliminate the interlayer gap and further improve the compactness of the titanium-steel composite plate.

[0045] Preferably, the pure titanium plate is selected from TA1 (pure titanium, the content of titanium is usually not less than 99.5%, and the impurity content is relatively low) or TA2 (commercially pure titanium, the content of titanium is slightly lower, usually above 98.5%, and contains trace elements such as iron, oxygen, and nitrogen).

[0046] Preferably, the thickness of the pure titanium plate is 0.1 - 8 mm; more preferably 0.5 - 5 mm; further preferably 0.5 mm, 2 mm or 4 mm.

[0047] Preferably, the surface roughness Ra of the pure titanium plate is controlled at 0.8 - 3.2.

[0048] Before use, the above pure titanium plate can also be subjected to surface cleaning or pretreatment to remove the surface oxides and impurities and improve its bonding force with the titanium-permeated steel substrate.

[0049] In the above preparation method, the pretreatment of the steel substrate in step (1) includes cleaning, degreasing, rust removal, etc., and the purpose is to ensure that the surface of the steel substrate is clean and free of impurities.

[0050] The steel substrate is selected from carbon steel.

[0051] The thickness of the carbon steel is preferably 0.5 - 8 mm, and the surface roughness Ra is controlled at 0.8 - 3.2. The present invention also provides a titanium-steel composite plate prepared by the above preparation method;

[0052] Preferably, the tensile strength of the titanium-steel composite plate is 680 - 900 MPa.

[0053] Compared with the prior art, the preparation method of the titanium-steel composite plate provided by the present invention includes the following steps:

[0054] (1) A titanium infiltration layer is formed on the surface of the pre-treated steel substrate through titanium infiltration treatment to obtain a titanium-infiltrated steel substrate; (2) The titanium-infiltrated steel substrate and the pure titanium plate are laminated and pre-pressed, and then subjected to double-pass composite rolling and heat treatment in sequence to obtain a titanium-steel composite plate; wherein, the first pass of the double-pass composite rolling adopts asynchronous isothermal rolling, and the second pass adopts isothermal symmetric rolling. The preparation method is simple and efficient, with low cost. A uniform and dense titanium layer is formed on the surface of the steel substrate through titanium infiltration treatment, enhancing the bonding force between the pure titanium plate and the steel substrate and avoiding the generation of harmful metal compounds. At the same time, the composite rolling technology combining asynchronous isothermal rolling and isothermal symmetric rolling effectively improves the internal microstructure and properties of the titanium-steel composite plate by regulating the rolling parameters. Detailed Embodiments

[0055] To further illustrate the present invention, the preparation method of the titanium-steel composite plate and the titanium-steel composite plate provided by the present invention will be described in detail below in conjunction with embodiments.

[0056] The atmosphere during the following heat treatment is a vacuum or argon protection atmosphere.

[0057] Example 1

[0058] Q235 carbon steel with a thickness of 4 mm is used as the substrate material. After surface cleaning, degreasing, rust removal and other pre-treatments, a uniform titanium layer with a thickness of about 0.1 mm is formed on the surface of the steel substrate by plasma titanium infiltration method.

[0059] Pure titanium TA1 with a thickness of 0.5 mm (the surface roughness Ra is controlled within 0.8 - 3.2) is selected as the clad material, and surface cleaning and pre-treatment are also carried out.

[0060] Subsequently, the titanium-infiltrated steel substrate and pure titanium TA1 are laminated and pre-pressed, and then sent to a rolling mill for double-pass composite rolling. The asynchronous ratio of the first pass of asynchronous rolling is 1.2, the rolling speed is 0.8 m / s, and the deformation amount is 35%; the intermediate annealing is carried out at 700 °C for 2 hours. The deformation amount of the second pass of isothermal symmetric rolling is set at 20%, and finally heat treatment is carried out at 600 °C and cooled in the furnace to obtain a titanium-steel composite plate. The tensile strength of the titanium-steel composite plate obtained in this example reaches 680 MPa, the interfacial shear strength reaches 242 MPa, the interface is tightly bonded, and no intermetallic compounds are generated, showing excellent mechanical properties and bonding strength.

[0061] Example 2

[0062] Select 45# medium carbon steel with a thickness of 6 mm as the substrate, and form a titanium layer with a thickness of about 0.2 mm on the surface through the solid powder titanium infiltration process. The pure titanium plate uses pure titanium TA2 with a thickness of 2 mm (the surface roughness Ra is controlled within 0.8 - 3.2), and necessary surface pretreatment is carried out. After laminating and pre-pressing, double-pass composite rolling is carried out. The asynchronous rolling speed ratio in the first pass is 1.2, the rolling speed is 1.0 m / s, and the deformation amount is 35%; the intermediate annealing is carried out at 650 °C for 3 hours. The deformation amount of the second-pass isothermal symmetric rolling is adjusted to 22%, and finally heat treatment is carried out at 680 °C. After furnace cooling, a titanium-steel composite plate is obtained. The tensile strength of the titanium-steel composite plate prepared in this example is as high as 720 MPa, and the interface shear strength is 272 MPa. The interface bonding strength is high, the mechanical properties are uniform, and it is suitable for application scenarios with higher strength requirements.

[0063] Example 3

[0064] Use 20Mn2 manganese carbon steel with a thickness of 8 mm as the substrate, and form a titanium layer with a thickness of about 0.3 mm on the surface through the paste titanium infiltration method. Select pure titanium TA1 with a thickness of 4 mm (the surface roughness Ra is controlled within 0.8 - 3.2) as the cladding material, and carry out surface cleaning and pretreatment. After laminating and pre-pressing, it is sent to the rolling mill for double-pass composite rolling. The asynchronous rolling speed ratio in the first pass is 1.2, the rolling speed is 1.2 m / s, and the deformation amount is 35%; the intermediate annealing is carried out at 700 °C for 4 hours. The deformation amount of the second-pass isothermal symmetric rolling is set to 20%, the heat treatment temperature is 720 °C, and after furnace cooling, a titanium-steel composite plate is obtained. The tensile strength of the titanium-steel composite plate obtained in this example reaches 750 MPa, the interface bonding quality is excellent, without defects, showing extremely high strength and good processing performance. The interface bonding rate ≥ 99.6%, and the interface shear strength reaches 300 MPa, which is suitable for the high-end equipment manufacturing field.

[0065] The descriptions of the above examples are only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a titanium-steel composite plate, characterized in that, It includes the following steps: (1) A titanium infiltration layer is formed on the surface of the pre-treated steel substrate through titanium infiltration treatment to obtain a titanium-infiltrated steel substrate; (2) The titanium-infiltrated steel substrate and the pure titanium plate are laminated and pre-pressed, and then subjected to double-pass composite rolling and heat treatment in sequence to obtain a titanium-steel composite plate; Among them, the first pass of the double-pass composite rolling adopts asynchronous isothermal rolling, and the second pass adopts isothermal symmetric rolling.

2. The preparation method according to claim 1, wherein The thickness of the titanium infiltration layer is 0.05 - 0.5 mm.

3. The preparation method according to claim 1, characterized in that, The method of the titanium infiltration treatment is selected from plasma titanium infiltration method or solid powder / paste metal infiltration method.

4. The preparation method according to claim 1, characterized in that, The upper and lower roll speed ratio in the asynchronous isothermal rolling is 1.1 - 1.4; The rolling speed in the asynchronous isothermal rolling is 0.628 - 1.2 m / s; The deformation amount in the asynchronous isothermal rolling is controlled within 35%.

5. The preparation method according to claim 1, characterized in that, The temperature of the annealing treatment in the asynchronous isothermal rolling is 550°C - 850°C; The time of the annealing treatment is 1 - 4 h.

6. The preparation method according to claim 1, characterized in that, The deformation amount in the isothermal symmetric rolling is controlled within 18% - 25%.

7. The preparation method according to claim 1, characterized in that, The temperature of the heat treatment in step (2) is 600°C - 900°C; The atmosphere during the heat treatment is vacuum or argon protection atmosphere.

8. The preparation method according to claim 1, wherein The pure titanium plate is selected from TA1 or TA2.

9. The preparation method according to claim 3, characterized in that, The thickness of the pure titanium plate is 0.1 - 8 mm; The surface roughness Ra of the pure titanium plate is controlled within 0.8 - 3.

2.

10. A titanium-steel composite plate, characterized in that, Prepared by the preparation method according to any one of claims 1 - 9; The tensile strength of the titanium-steel composite plate is 680 - 900 MPa.