Lightweight corrosion-resistant ultrahigh-strength multilayer titanium steel composite plate and preparation method thereof

Abstract

The invention provides a light corrosion-resistant ultrahigh-strength multilayer titanium-steel composite plate and a preparation method thereof. The titanium-steel composite plate comprises titanium or titanium alloy coating layers on the upper outer surface side and the lower outer surface side, a martensitic stainless steel layer of a steel material layer and a transition layer arranged between titanium and steel. The assembly raw material of the steel material layer is a high-carbon martensitic stainless steel plate, the assembly raw material of the titanium material layer is an industrial titanium or titanium alloy plate, and the assembly raw material of the transition layer is a 430 stainless steel thin plate. Each group of blank raw materials are the same in length and width and different in thickness. Through reasonable assembly (including transition layer metal selection) and rolling temperature control, the rolling process is optimized, diffusion of alloy elements at an interface and formation of intermetallic compounds are controlled, and therefore preparation of the light-weight and ultrahigh-strength multi-layer corrosion-resistant titanium steel composite plate is achieved.

Description

[Technical field]

[0001] The invention relates to the technical field of titanium / steel composite plate preparation, and in particular to a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate and a preparation method thereof. [Background technology]

[0002] The high-end hardware knife and scissors industry has developed rapidly in recent years, mainly due to the technological innovation of high-performance materials, processing technology, and appearance design and the development of market demand. With the continuous improvement of people's production and living standards, the modern tool manufacturing industry uses high-performance materials such as ceramics or titanium alloys, as well as advanced manufacturing technologies such as powder metallurgy and laser cladding to produce high-quality knife and scissors products. However, in the actual production process, traditional medium and high carbon martensitic stainless steel has high strength and good wear resistance (Rockwell hardness HRC: 53~62), but the tool itself is heavy (density: 7.80g / cm 3 ), which is not conducive to outdoor or long-distance carrying; high-tech titanium alloy knives have low density (density: 4.75g / cm 3 ), easy to use, but its hardness is low (Rockwell hardness HRC <40), which greatly reduces its practicality. Other high-quality knives such as zirconia ceramic knives, although harder than traditional martensitic stainless steel, are more brittle and prone to brittle fracture. Therefore, new high-end knife and scissors products need to take into account many factors such as wear resistance, corrosion resistance, light weight, and high toughness.

[0003] As we all know, titanium / steel cladding refers to the connection of two heterogeneous metals through physical metallurgy or mechanical biting. The main preparation methods of titanium / steel composite plates are: explosion cladding, diffusion cladding, explosion cladding-rolling and rolling cladding. Among them, rolling cladding is the main development direction at present, which can greatly reduce the production cost of titanium / steel / composite plates. Therefore, rolling cladding of high-carbon martensitic stainless steel and titanium alloy can not only utilize the high strength and high wear resistance of medium-high carbon martensitic stainless steel, but also utilize the corrosion resistance and low density of titanium alloy, and has great market application prospects.

[0004] CN105107841A discloses a method for preparing a titanium / steel composite plate, wherein the titanium / steel direct composite rolling technology is used to prepare the titanium / steel composite plate, wherein the steel plate is a plain carbon steel plate, and the titanium plate is an industrial pure titanium plate (TA1 or TA2), wherein the preparation process is simple, and the interface bonding strength is improved by a higher final rolling temperature. CN101992344A discloses a three-layer titanium-steel composite plate and a method for preparing the same, wherein the steel plate is a 304 austenitic stainless steel plate, and the titanium plate is an industrial pure titanium plate A2, and different titanium-steel interface bonding strengths are achieved by changing the compression ratio at different temperatures. However, the steel substrates of these composite plates are mostly plain carbon steel, low alloy steel or austenitic stainless steel, and their strength is generally low (HRC≤25), so their performance in terms of wear resistance is poor, which greatly limits the development and application promotion of high-end titanium / steel composite hardware knife and scissors products.

[0005] Therefore, in order to further expand the application of titanium steel composite plates in the field of high-end hardware knives and scissors, it is urgently necessary to develop a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium steel composite plate and its preparation method to address the shortcomings of the existing technology and solve or alleviate one or more of the above problems. [Summary of the invention]

[0006] In view of this, the present invention provides a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate and a preparation method thereof, and particularly relates to a method for producing a lightweight, high-hardness, corrosion-resistant multi-layer titanium-steel composite plate and a process method thereof using key rolling and heat treatment technologies. By reasonably controlling the blanking and rolling temperature, optimizing the rolling process and the subsequent timely heat treatment process, controlling the diffusion of alloy elements at the interface and the formation of intermetallic compounds, the rolling composite of high-carbon martensitic stainless steel and titanium and titanium alloys is achieved.

[0007] On the one hand, a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate is provided, comprising: a steel layer, a titanium layer and a transition layer, wherein the titanium layer is located on both sides of the upper and lower outer surfaces of the steel layer, and the transition layer is placed between the steel layer and the titanium layer; the raw material for the steel layer is a high-carbon martensitic stainless steel plate, the raw material for the titanium layer is an industrial titanium or titanium alloy plate, and the raw material for the transition layer is a 430 stainless steel thin plate, and the length and width of each raw material are the same but the thickness is different.

[0008] According to the above aspects and any possible implementation, an implementation is further provided, wherein the high carbon martensitic stainless steel plate includes one or more of 5Cr15MoV, 7Cr17MoV, 8Cr13MoV, 9Cr18MoV, 440C, and M390.

[0009] According to the above aspects and any possible implementation, an implementation is further provided, wherein the industrial titanium plate comprises one or more of TA1, TA2, TC4 and Ti-55531.

[0010] According to the above aspects and any possible implementation, a further implementation is provided, wherein the length of the steel layer is 0.5 to 1 m, the width is 0.1 to 0.5 m, and the thickness is L S 5~25mm.

[0011] According to the above aspects and any possible implementation, an implementation is further provided, wherein the titanium layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness L T 10~40mm.

[0012] According to the above aspects and any possible implementation, a further implementation is provided, wherein the thickness of the steel layer is less than or equal to 1.5 times that of the titanium layer, i.e., L S ≤1.5L T .

[0013] According to the above aspects and any possible implementation, an implementation is further provided, wherein the transition layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L i It is 150~500μm.

[0014] According to the aspects and any possible implementation methods described above, an implementation method is further provided, wherein the titanium-steel composite plate also includes four circumferential side plate layers and a vacuum titanium pipe located at the head, and the four circumferential side plate layers are respectively coated on the four circumferential sides of the blank composed of the steel layer, the titanium layer and the transition layer, and the thickness of the circumferential side plate layers is 15 to 20 mm.

[0015] According to the above aspects and any possible implementation, a method for preparing a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate is further provided, which is used to prepare the titanium-steel composite plate, and the preparation method comprises the following steps:

[0016] S1: Preset a steel layer, a titanium layer, a coating layer and a transition layer, wherein the coating layer is arranged outside the titanium layer, and the transition layer is arranged between the steel layer and the titanium layer;

[0017] S2: Select high carbon martensitic stainless steel plate as the raw material for the steel layer, and select industrial titanium or titanium alloy plate as the raw material for the titanium layer;

[0018] S3: Select industrial titanium TA1 plate as the raw material for the cladding layer, and select 430 stainless steel thin plate as the raw material for the transition layer;

[0019] S4: pre-treating the surfaces of the steel layer and the titanium layer to be in contact;

[0020] S5: assembling the composite plate in a preset manner;

[0021] S6: A circular hole with a diameter of 5 to 10 mm is reserved at any end of the coating layer in the length direction to form a first composite blank;

[0022] S7: Perform multiple passes of argon arc welding on the four sides of the first composite billet, with a weld depth of 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa, forming a second composite blank;

[0023] S8: heating the second composite billet to 900±25°C and keeping the temperature for 2-4h, the start rolling temperature is 850±25°C, the single pass reduction rate is 20%-35%, the total reduction rate is ≥85%, and the final rolling temperature is above 725°C;

[0024] S9: Immediately after rolling, the slab is heated to between 920 and 1075° C., kept at this temperature for 5 to 20 minutes, and then oil-cooled to room temperature to form a third composite slab;

[0025] S10: trimming and surface grinding the third composite blank to obtain a titanium-steel composite plate with a thickness of 3 to 15 mm. The plate width can reach 1.5 to 3 m, and the thickness ratio of the titanium / steel / titanium layer is adjustable.

[0026] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein the preprocessing process in S4 includes:

[0027] S41: machining the surfaces of the steel layer and the titanium layer to be in contact by a grinder to remove scales and stains on the surfaces to be in contact;

[0028] S42: Use alcohol solvent to deeply clean the surface of the machined steel layer and titanium layer and blow dry the workpiece surface.

[0029] Compared with the prior art, the present invention can achieve the following technical effects:

[0030] 1) Innovatively select 430 ferritic stainless steel sheet as transition layer metal. On the one hand, the rolling composite of high-carbon martensitic stainless steel and titanium and titanium alloy on both sides is realized, which greatly improves the interface bonding strength between martensitic stainless steel and titanium; on the other hand, compared with ordinary transition layer metal materials such as IF steel, 430 ferritic stainless steel has higher corrosion resistance, which can improve the comprehensive corrosion resistance of multi-layer composite plates;

[0031] 2) By timely short-time high-temperature annealing after rolling, the dissolution and diffusion behavior of carbon elements are regulated, and ultra-high-strength martensitic structure is obtained by rapid cooling such as oil cooling, and ultra-high-strength multi-layer titanium-steel composite plates are prepared, and the Rockwell hardness HRC range of the core steel layer is 54-62;

[0032] 3) Through the composite of titanium alloy on both sides, the weight of the component is greatly reduced without sacrificing the hardness and wear resistance of high carbon martensitic stainless steel. In the present invention, the average density of the composite plate is ≤6.05g / cm 3 , which is more than 22.4% lighter than martensitic stainless steel.

[0033] Of course, any product implementing the present invention does not necessarily need to achieve all of the above-mentioned technical effects at the same time.

Brief Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 This is a method for assembling a composite plate provided by an embodiment of the present invention;

[0036] Figure 2 This is a low-magnification microstructure photograph of a multi-layer composite plate obtained after rolling and corrosion according to an embodiment of the present invention;

[0037] Figure 3 It is a Vickers hardness measurement curve diagram of a titanium / steel composite billet in a rolled state and after heat treatment provided by an embodiment of the present invention.

[0038] Among them, in the figure:

[0039] Titanium and titanium alloys-1 and 2, high carbon martensitic stainless steel-3, transition layer 430 stainless steel-4 and 5, peripheral cladding layer titanium plate TA1 (one piece on each side)-6, titanium tube channel for vacuum extraction-7. [Specific implementation method]

[0040] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] It should be clear that the described embodiments are only some embodiments of the present invention, not all 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.

[0042] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0043] like Figure 1 As shown, the present invention provides a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate, the titanium-steel composite plate is composed of a steel layer, a titanium layer, a coating layer and a transition layer, wherein:

[0044] The titanium layer is located on both sides of the upper and lower outer surfaces of the steel layer, and the transition layer is placed between the steel layer and the titanium layer; the raw material for the steel layer is a high-carbon martensitic stainless steel plate, the raw material for the titanium layer is an industrial titanium or titanium alloy plate, and the raw material for the transition layer is a 430 stainless steel thin plate. The length and width of each raw material are the same, but the thickness is different.

[0045] The high carbon martensitic stainless steel plate includes one or more of 5Cr15MoV, 7Cr17MoV, 8Cr13MoV, 9Cr18MoV, 440C, and M390.

[0046] The industrial titanium plate includes one or more of TA1, TA2, TC4 and Ti-55531.

[0047] The steel layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L S 5~25mm.

[0048] The titanium layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L T 10~40mm.

[0049] The thickness of the steel layer is less than or equal to 1.5 times that of the titanium layer, i.e., L S ≤1.5L T .

[0050] The transition layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L i It is 150~500μm.

[0051] The titanium steel composite plate also includes four peripheral side plate layers and a vacuum titanium pipe located at the head. The four peripheral side plate layers are respectively coated on the four peripheral sides of the upper and lower connected titanium / steel / titanium composite blanks, and the thickness of the coated plate is 15-20 mm.

[0052] The present invention also provides a method for preparing a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate, which is used to prepare the titanium-steel composite plate. The preparation method comprises the following steps:

[0053] S1: Preset a steel layer, a titanium layer, a coating layer and a transition layer, wherein the coating layer is arranged outside the titanium layer, and the transition layer is arranged between the steel layer and the titanium layer;

[0054] S2: Select high carbon martensitic stainless steel plate as the raw material for the steel layer, and select industrial titanium or titanium alloy plate as the raw material for the titanium layer;

[0055] S3: Select industrial titanium TA1 plate as the raw material for the cladding layer, and select 430 stainless steel thin plate as the raw material for the transition layer;

[0056] S4: pre-treating the surfaces of the steel layer and the titanium layer to be in contact;

[0057] S5: assembling the composite plate in a preset manner;

[0058] S6: A circular hole with a diameter of 5 to 10 mm is reserved at any end of the coating layer in the length direction to form a first composite blank;

[0059] S7: Perform multiple passes of argon arc welding on the four sides of the composite billet, with a weld depth of 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa, forming a second composite blank;

[0060] S8: heating the second composite billet to 900±25°C and keeping the temperature for 2-4h, the start rolling temperature is 850±25°C, the single pass reduction rate is 20%-35%, the total reduction rate is ≥85%, and the final rolling temperature is above 725°C;

[0061] S9: Immediately after rolling, the slab is heated to between 920 and 1075° C., kept at this temperature for 5 to 20 minutes, and then oil-cooled to room temperature to form a third composite slab;

[0062] S10: trimming and surface grinding the third composite blank to obtain a titanium-steel composite plate with a thickness of 3 to 15 mm. The plate width can reach 1.5 to 3 m, and the thickness ratio of the titanium / steel / titanium layer is adjustable.

[0063] The low-magnification microstructure photograph of the multilayer composite plate obtained after rolling and corrosion is shown in Figure 2 As shown, 430 ferritic stainless steel is used as the transition layer in S3. On the one hand, considering that it has a relatively low hardness (Vickers hardness of 180Hv), it plays a vital role in realizing the rolling composite of titanium and high carbon martensitic stainless steel; on the other hand, unlike other metal materials, the 430 ferritic stainless steel transition layer itself has a relatively high corrosion resistance, which is beneficial to improving the overall corrosion resistance of the composite plate (especially when the composite layer is exposed).

[0064] Heating the rolled slab to between 920 and 1075°C and keeping it warm for 5-20 minutes in S9 is the key to achieving high-strength and wear-resistant composite plates. Annealing at 920-1075°C can dissolve carbon back into the austenite matrix, and obtain a full high-hardness martensitic structure during subsequent rapid cooling; the holding time is also extremely important. When the time exceeds 30-60 minutes (varies with temperature), carbon atoms will diffuse into the titanium coating in large quantities and form a brittle phase at the titanium-steel interface. Therefore, the holding time needs to be controlled at around 5-20 minutes. The Vickers hardness measurement curves of the titanium / steel composite billet in the rolled state and after heat treatment are shown in the figure below. Figure 3 shown.

[0065] The preprocessing process in S4 includes:

[0066] S41: machining the surfaces of the steel layer and the titanium layer to be in contact by a grinder to remove scales and stains on the surfaces to be in contact;

[0067] S42: Use alcohol solvent to deeply clean the surface of the machined steel layer and titanium layer and blow dry the workpiece surface.

[0068] Embodiment 1:

[0069] Assembly materials:

[0070] Steel: 5Cr15MoV (mass percentage wt.%, C: 0.45~0.55%, Si≤0.80%, Mn≤0.80%, Mo: 0.5~0.8%, V: 0.1~0.3%, Cr: 14.0~16.0%, Ni≤0.6%, P≤0.04%, S≤0.015%), size: 200×600×10mm.

[0071] Titanium material: pure titanium TA1 (mass percentage wt.%, H≤0.015%, O≤0.20%, Fe≤0.25%, C≤0.10%, N≤0.03%, the remainder is Ti), size: 200×600×10mm.

[0072] Transition layer: 430 stainless steel (mass percentage wt.%, C≤0.12%, Si≤0.80%, Mn≤0.80%, Cr: 16.0-18.0%, P≤0.04%, S≤0.015%), size: 200×600×0.4mm.

[0073] The specific steps are as follows:

[0074] S1: Use a grinder to machine the contact surfaces of steel and titanium to remove scale and stains on the contact surfaces; use alcohol solvent to deeply clean the processed steel and titanium surfaces and blow dry the workpiece surface.

[0075] S2: The materials and methods of the blank assembly are from top to bottom: TA1 titanium coating, 430 stainless steel sheet, 5Cr15MoV high carbon martensitic stainless steel layer, 430 stainless steel sheet, TA1 titanium coating.

[0076] S3: The four sides of the composite blank are completely fixed with TA1 titanium plates, and a circular hole with a diameter of 5 to 10 mm is left on one side for sealing after vacuuming to form a composite blank; the four sides of the composite blank are subjected to multi-pass argon arc welding, and the weld depth is 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa.

[0077] S4: The composite billet after welding is heated to 900±25℃ and kept warm for 2h. The rolling temperature is 850±25℃, the single-pass reduction rate is 30%, the total reduction rate is ≥85%, and the final rolling temperature is above 725℃.

[0078] S5: Immediately after rolling, heat the slab to 975°C, keep it at this temperature for 15 minutes, and then oil cool it to room temperature.

[0079] S6: After the rolled composite plate is trimmed and the surface is ground, a high-strength titanium steel composite plate with a thickness of 5.5 mm is obtained, the plate width can reach 2.9 m, and the compression ratio of the composite plate is 0.85.

[0080] Main performance:

[0081] 1) Average density: The average density of the titanium steel composite plate is 5.77g / cm 3 , 26.1% lighter than traditional martensitic stainless steel;

[0082] 2) Hardness: The core Rockwell hardness of the titanium steel composite plate is 55HRC, which is equivalent to the hardness of traditional 5Cr15MoV.

[0083] Embodiment 2:

[0084] Assembly materials:

[0085] Steel: 9Cr18MoV (mass percentage wt.%, C: 0.85-0.95%, Si≤0.80%, Mn≤0.80%, Mo: 1.0-1.3%, V: 0.07-0.12%, Cr: 17.0-19.0%, Ni≤0.6%, P≤0.04%, S≤0.015%), size: 200×600×12mm.

[0086] Titanium material: TC4 (mass percentage by wt.%, Al≤6.00%, V≤4.00%, Fe≤0.3%, C≤0.08%, N≤0.05%, the remainder is Ti), size: 200×600×15mm.

[0087] Transition layer: 430 stainless steel (mass percentage wt.%, C≤0.12%, Si≤0.80%, Mn≤0.80%, Cr: 16.0-18.0%, P≤0.04%, S≤0.015%), size: 200×600×0.4mm.

[0088] The specific steps are as follows:

[0089] S1: Use a grinder to machine the contact surfaces of steel and titanium to remove scale and stains on the contact surfaces; use alcohol solvent to deeply clean the processed steel and titanium surfaces and blow dry the workpiece surface.

[0090] S2: The materials and methods of the blank assembly are from top to bottom: TC4 titanium coating, 430 stainless steel sheet, 9Cr18MoV high carbon martensitic stainless steel layer, 430 stainless steel sheet, TC4 titanium coating.

[0091] S3: The four sides of the composite blank are completely fixed with TA1 titanium plates, and a circular hole with a diameter of 5 to 10 mm is left on one side for sealing after vacuuming to form a composite blank; the four sides of the composite blank are subjected to multi-pass argon arc welding, and the weld depth is 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa.

[0092] S4: The composite billet after welding is heated to 900±25℃ and kept warm for 2h. The rolling temperature is 850±25℃, the single-pass reduction rate is 30%, the total reduction rate is ≥85%, and the final rolling temperature is above 725℃.

[0093] S5: Immediately after rolling, the slab is heated to 1000°C, kept at this temperature for 12 minutes, and then oil-cooled to room temperature.

[0094] S6: After the rolled composite plate is trimmed and the surface is ground, a high-strength titanium steel composite plate with a thickness of 6.1 mm is obtained. The plate width can reach 3.8 m, and the compression ratio of the composite plate is 0.85.

[0095] Main performance:

[0096] 1) Average density: The average density of the titanium steel composite plate is 5.62g / cm 3 , 27.9% lighter than traditional martensitic stainless steel;

[0097] 2) Hardness: The core Rockwell hardness of the titanium steel composite plate is 58HRC, which is equivalent to the hardness of traditional 9Cr18MoV.

[0098] Embodiment 3:

[0099] Assembly materials:

[0100] Steel: M390 (mass percentage wt.%, C: 1.9-2.0%, Si: 0.7-1.0%, Mn: 0.3-0.6%, Mo: 1.0-2.0%, V: 3.8-4.4%, Cr: 19.0-21.0%, W: 0.6-1.0%, P≤0.04%, S≤0.015%), size: 200×600×10mm.

[0101] Titanium material: Ti-55531 (mass percentage wt.%, Al: 4.5-5.5%, Mo: 4.5-5.5%, V: 4.5-5.5%, Cr: 2.5-3.5%, Zr: 0.5-1.5%, Fe≤0.3%, C≤0.08%, N≤0.05%, balance Ti), size: 200×600×15mm.

[0102] Transition layer: 430 stainless steel (mass percentage wt.%, C≤0.12%, Si≤0.80%, Mn≤0.80%, Cr: 16.0-18.0%, P≤0.04%, S≤0.015%), size: 200×600×0.4mm.

[0103] The specific steps are as follows:

[0104] S1: Use a grinder to machine the contact surfaces of steel and titanium to remove scale and stains on the contact surfaces; use alcohol solvent to deeply clean the processed steel and titanium surfaces and blow dry the workpiece surface.

[0105] S2: The materials and methods of the blank assembly are from top to bottom: Ti-55531 titanium cladding, 430 stainless steel sheet, M390 high carbon martensitic stainless steel layer, 430 stainless steel sheet, Ti-55531 titanium cladding.

[0106] S3: The four sides of the composite blank are completely fixed with TA1 titanium plates, and a circular hole with a diameter of 5 to 10 mm is left on one side for sealing after vacuuming to form a composite blank; the four sides of the composite blank are subjected to multi-pass argon arc welding, and the weld depth is 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa.

[0107] S4: The composite billet after welding is heated to 900±25℃ and kept warm for 2h. The rolling temperature is 850±25℃, the single-pass reduction rate is 30%, the total reduction rate is ≥90%, and the final rolling temperature is above 725℃.

[0108] S5: Immediately after rolling, heat the slab to 1055°C, keep it at that temperature for 8 minutes, and then oil cool it to room temperature.

[0109] S6: After the rolled composite plate is trimmed and the surface is ground, a high-strength titanium steel composite plate with a thickness of 4.0 mm is obtained, the plate width can reach 5.6 m, and the compression ratio of the composite plate is 0.90.

[0110] Main performance:

[0111] 1) Average density: The average density of the titanium steel composite plate is 5.51g / cm 3 , 29.3% lighter than traditional martensitic stainless steel;

[0112] 2) Hardness: The core Rockwell hardness of the titanium-steel composite plate is 61HRC, which is equivalent to the hardness of traditional M390.

[0113] The above is a detailed introduction to a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium steel composite plate and its preparation method provided in the embodiments of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application; at the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0114] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0115] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0116] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0117] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium steel composite plate, characterized in that: The titanium-steel composite plate includes: a steel layer, a titanium layer and a transition layer, wherein the titanium layer is located on both sides of the upper and lower outer surfaces of the steel layer, and the transition layer is placed between the steel layer and the titanium layer; the raw material for the steel layer is a high-carbon martensitic stainless steel plate, the raw material for the titanium layer is an industrial titanium or titanium alloy plate, and the raw material for the transition layer is a 430 stainless steel thin plate, and the length and width of each raw material are the same but the thickness is different.

2. The titanium steel composite plate according to claim 1, characterized in that: The high carbon martensitic stainless steel plate includes one or more of 5Cr15MoV, 7Cr17MoV, 8Cr13MoV, 9Cr18MoV, 440C, and M390.

3. The titanium steel composite plate according to claim 1, characterized in that: The industrial titanium plate includes one or more of TA1, TA2, TC4 and Ti-55531.

4. The titanium steel composite plate according to claim 1, characterized in that: The length of the steel layer is 0.5-1m, the width is 0.1-0.5m, and the thickness is L S 5~25mm.

5. The titanium steel composite plate according to claim 1, characterized in that: The titanium layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L T 10~40mm.

6. The titanium steel composite plate according to claim 1, characterized in that: The thickness of the steel layer is less than or equal to 1.5 times that of the titanium layer, i.e., L S ≤1.5L T .

7. The titanium steel composite plate according to claim 1, characterized in that: The transition layer has a length of 0.5 to 1 m, a width of 0.1 to 0.5 m, and a thickness of L i It is 150~500μm.

8. The titanium steel composite plate according to claim 1, characterized in that: The titanium steel composite plate also includes four peripheral side plate layers and a vacuum titanium pipe located at the head. The four peripheral side plate layers are respectively coated on the four peripheral sides of the blank composed of the steel layer, the titanium layer and the transition layer. The thickness of the peripheral side plate layers is 15 to 20 mm.

9. A method for preparing a lightweight, corrosion-resistant, ultra-high-strength multi-layer titanium-steel composite plate, used for preparing the titanium-steel composite plate according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1: Preset a steel layer, a titanium layer, a coating layer and a transition layer, wherein the coating layer is arranged outside the titanium layer, and the transition layer is arranged between the steel layer and the titanium layer; S2: Select high carbon martensitic stainless steel plate as the raw material for the steel layer, and select industrial titanium or titanium alloy plate as the raw material for the titanium layer; S3: Select industrial titanium TA1 plate as the raw material for the cladding layer, and select 430 stainless steel thin plate as the raw material for the transition layer; S4: pre-treating the surfaces of the steel layer and the titanium layer to be in contact; S5: assembling the composite plate in a preset manner; S6: A circular hole with a diameter of 5 to 10 mm is reserved at any end of the coating layer in the length direction to form a first composite blank; S7: Perform multiple passes of argon arc welding on the four sides of the first composite billet, with a weld depth of 15 to 20 mm. After welding, vacuum treatment is performed through the reserved holes, and the vacuum degree is less than 1×10 -2 Pa, forming a second composite blank; S8: heating the second composite billet to 900±25°C and keeping the temperature for 2-4h, the start rolling temperature is 850±25°C, the single pass reduction rate is 20%-35%, the total reduction rate is ≥85%, and the final rolling temperature is above 725°C; S9: Immediately after rolling, the slab is heated to between 920 and 1075° C., kept at this temperature for 5 to 20 minutes, and then oil-cooled to room temperature to form a third composite slab; S10: trimming and surface grinding the third composite blank to obtain a titanium-steel composite plate with a thickness of 3 to 15 mm. The plate width can reach 1.5 to 3 m, and the thickness ratio of the titanium / steel / titanium layer is adjustable.

10. The preparation method according to claim 9, characterized in that: The preprocessing process in S4 includes: S41: machining the surfaces of the steel layer and the titanium layer to be in contact by a grinder to remove scales and stains on the surfaces to be in contact; S42: Use alcohol solvent to deeply clean the surface of the machined steel layer and titanium layer and blow dry the workpiece surface.

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