Copper-steel composite board and preparation method thereof

Abstract

The invention relates to a copper-steel composite plate and a preparation method thereof, the copper-steel composite plate comprises an outer layer carbon steel plate and a core layer oxygen-free pure copper plate, and at least one surface of the oxygen-free pure copper plate integrally and continuously covers the carbon steel plate; the carbon steel plate comprises the following chemical components: 0.05%-0.20% of C, 0.1%-0.55% of Si, 0.5%-2.0% of Mn, less than or equal to 1.0% of Cr, less than or equal to 1.5% of Ni, less than or equal to 1.0% of Cu and the balance of Fe. The thickness of the copper-steel composite plate is 30-120 mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4-0.8. According to the copper-steel composite plate, the yield strength is larger than or equal to 209 MPa, the tensile strength is larger than or equal to 359 MPa, the shear strength is larger than or equal to 213 MPa, and the copper-steel composite plate has good structural strength and interface bonding strength.

Description

Technical Field

[0001] The present application relates to the technical field of composite plate preparation, and in particular to a copper-steel composite plate and a preparation method thereof. Background Art

[0002] Copper-steel composite plates combine the excellent properties of copper and steel, and can simultaneously bring into play the excellent thermal conductivity of copper and the high strength and wear resistance of steel.

[0003] At present, the preparation methods of copper-steel composite plates are mainly explosive composite and rolling composite. At present, it mainly involves thin specifications (the copper layer generally accounts for ≤10%) or copper-steel single-sided (two-layer) composite products and manufacturing processes, and there are no thick specifications multi-layer copper-steel composite plates and their manufacturing methods. Summary of the invention

[0004] The present application provides a copper-steel composite plate and a preparation method thereof to solve the following technical problems: providing a thick copper-steel composite plate.

[0005] In a first aspect, the present application provides a copper-steel composite plate, the copper-steel composite plate comprising an outer carbon steel plate and a core oxygen-free pure copper plate, at least one side of the oxygen-free pure copper plate is entirely and continuously coated with the carbon steel plate;

[0006] The chemical composition of the carbon steel plate includes: C, Si, Mn, Cr, Ni and Cu; wherein, in terms of mass fraction,

[0007] The content of C is 0.05% to 0.20%, the content of Si is 0.1% to 0.55%, the content of Mn is 0.5% to 2.0%, the content of Cr is ≤1.0%, the content of Ni is ≤1.5%, and the content of Cu is ≤1.0%;

[0008] The thickness of the copper-steel composite plate is 30 mm to 120 mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4 to 0.8.

[0009] Optionally, the chemical composition further includes at least one of the following: Mo and B; wherein the content of Mo is ≤0.5%, and the content of B is 0.0002% to 0.002%.

[0010] Optionally, the copper-steel composite plate meets the following mechanical properties: yield strength ≥ 209 MPa, tensile strength ≥ 359 MPa, and shear strength ≥ 213 MPa.

[0011] In a second aspect, the present application provides a method for preparing the copper-steel composite plate according to the first aspect, the method comprising:

[0012] The oxygen-free pure copper plate and the carbon steel plate are combined to obtain a composite steel billet having a multi-layer copper-steel laminated structure;

[0013] Vacuum welding the composite steel billet having a multi-layer copper-steel laminated structure to obtain a welded composite steel billet having a multi-layer copper-steel laminated structure;

[0014] The welded composite steel billet with a multi-layer copper-steel laminated structure is subjected to warm furnace heating, rolling and heat treatment to obtain a copper-steel composite plate.

[0015] Optionally, the process parameters of the vacuum welding include: vacuum degree, welding speed and welding beam current.

[0016] Optionally, the vacuum degree is ≤0.01Pa.

[0017] Optionally, the welding speed is 100 mm / min to 310 mm / min, and the welding beam current is 40 mA to 320 mA.

[0018] Optionally, the heating temperature is 850° C. to 1060° C., and the heat preservation time is 0.5 h to 3 h.

[0019] Optionally, the rolling process parameters include:

[0020] Single pass deformation rate, total pass deformation rate, rolling rate and final rolling temperature; among which,

[0021] The deformation rate of a single pass is 4% to 15%, the deformation rate of the total passes is ≥50%, the rolling rate is 2m / s to 5m / s, and the final rolling temperature is ≥750°C.

[0022] Optionally, the surface roughness Ra of the oxygen-free pure copper plate and the carbon steel plate are both ≤80 μm.

[0023] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0024] The copper-steel composite plate provided in an embodiment of the present application comprises an outer carbon steel plate and a core oxygen-free pure copper plate, and at least one side of the oxygen-free pure copper plate is continuously coated with the carbon steel plate as a whole; the chemical composition of the carbon steel plate comprises: C, Si, Mn, Cr, Ni and Cu; wherein, in terms of mass fraction, the content of C is 0.05% to 0.20%, the content of Si is 0.1% to 0.55%, the content of Mn is 0.5% to 2.0%, the content of Cr is ≤1.0%, the content of Ni is ≤1.5%, and the content of Cu is ≤1.0%; the thickness of the copper-steel composite plate is 30 mm to 120 mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4 to 0.8. At least one side of the core layer oxygen-free pure copper plate is continuously coated with an outer layer of carbon steel plate as a whole, and the chemical composition of the carbon steel plate is reasonably designed to ensure the mechanical properties and weldability of the carbon steel plate; through the composite of the carbon steel plate and the oxygen-free pure copper plate, the interface bonding degree is high, and the thickness of the copper-steel composite plate is 30mm-120mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4-0.8, while obtaining good thermal conductivity, it has sufficient strength and excellent economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 The present invention is a schematic diagram of a process for preparing a copper-steel composite plate according to some embodiments of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0030] In this application, in the description of the specification of this application, the terms "including", "comprising", etc. mean "including but not limited to".

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] In a first aspect, the present application provides a copper-steel composite plate, the copper-steel composite plate comprising an outer carbon steel plate and a core oxygen-free pure copper plate, at least one side of the oxygen-free pure copper plate is entirely and continuously coated with the carbon steel plate;

[0033] The chemical composition of the carbon steel plate includes: C, Si, Mn, Cr, Ni and Cu; wherein, in terms of mass fraction,

[0034] The content of C is 0.05% to 0.20%, the content of Si is 0.1% to 0.55%, the content of Mn is 0.5% to 2.0%, the content of Cr is ≤1.0%, the content of Ni is ≤1.5%, and the content of Cu is ≤1.0%;

[0035] The thickness of the copper-steel composite plate is 30 mm to 120 mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4 to 0.8.

[0036] In some embodiments, the chemical composition further includes at least one of the following: Mo and B; wherein the content of Mo is ≤0.5%, and the content of B is 0.0002% to 0.002%.

[0037] In some embodiments, the copper-steel composite plate meets the following mechanical properties: yield strength ≥ 209 MPa, tensile strength ≥ 359 MPa, and shear strength ≥ 213 MPa.

[0038] In the embodiment of the present application, in the chemical composition design of the outer carbon steel plate, C (carbon): carbon is a strengthening element that can improve the strength of steel, but too high a carbon content will increase the carbon equivalent, thereby affecting the weldability of the steel plate. For example, the C content can be 0.05%, 0.10%, 0.15%, 0.20%, etc.

[0039] Mn (manganese): Manganese is a solid solution strengthening element that can improve the strength and hardness of steel. Too high a content of Mn can easily lead to component segregation in the thickness section of the steel plate and increase the carbon equivalent, thereby affecting the uniformity of the cross-sectional structure and welding performance of the steel plate. For example, the content of Mn can be 0.10%, 0.2%, 0.3%, 0.4%, 0.5%, 0.55%, etc.

[0040] Cr (chromium): Cr can increase the strength and corrosion resistance of steel to a certain extent. Too low a Cr content cannot play a reinforcing role, while too high a Cr content affects weldability. For example, the Cr content can be 1.0%, 0.8%, 0.7%, 0.6%, etc.

[0041] Ni (nickel): Nickel has the function of improving low temperature toughness. Appropriate addition is beneficial to increasing the toughness of the base layer, while too high a content will affect the economy and weldability. For example, the Ni content can be 1.5%, 1.4%, 1.3%, 1.2%, etc.

[0042] Cu (copper): Copper has a certain strengthening effect, and too high a Cu content is detrimental to weldability. For example, the Cu content may be 1%, 0.9%, 0.8%, 0.7%, and the like.

[0043] In addition, the chemical composition of the carbon steel plate also includes impurity elements (P, S, and N). In order to prevent the influence of the impurity elements, P≤0.020%, S≤0.020%, and N≤0.020%.

[0044] In addition, considering that the outer steel plate needs to play a role in wear resistance and strength support, for the case where the wear resistance and heat resistance requirements are higher, the outer carbon steel can also add Mo and B and other elements to improve the wear resistance and heat resistance. Among them, the B element delays the ferrite / pearlite transformation through grain boundary solid solution segregation, which can significantly improve the hardenability and hardness of the steel, but the addition of too much B is prone to precipitation, thereby losing the beneficial effect of grain boundary segregation. Mo and Cr can improve the high temperature strength and wear resistance of steel together, but too high is not good for economy and weldability. Exemplarily, the content of the above Mo can be 0.5%, 0.4%, 0.3%, 0.2%, etc., and the content of the above B can be 0.0002%, 0.0005%, 0.001%, 0.0015%, 0.002%, etc.

[0045] Compared with pure copper structure, it has a longer service life, can save copper usage, greatly reduce costs, and has good economic benefits. Oxygen-free pure copper is selected to prevent oxidation and introduction of impurities in the preparation of steel-copper composite plates.

[0046] Through the composite of carbon steel plate and oxygen-free pure copper plate, the interface bonding degree is high, and the copper-steel composite plate has a high ratio of the thickness of the thick specification oxygen-free pure copper plate, while obtaining good thermal conductivity, it has sufficient strength and excellent economy, and meets the yield strength ≥ 209MPa, tensile strength ≥ 359MPa, and shear strength ≥ 213MPa. Exemplarily, the thickness of the copper-steel composite plate can be 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, etc., and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate can be 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0047] In a second aspect, the present application provides a method for preparing the copper-steel composite plate described in the first aspect, Figure 1 A schematic diagram of a process for preparing a copper-steel composite plate according to some embodiments of the present application; see Figure 1 , the method comprising:

[0048] S1. Combining an oxygen-free pure copper plate with a carbon steel plate to obtain a composite steel billet having a multi-layer copper-steel laminated structure;

[0049] In some embodiments, the surface roughness Ra of the oxygen-free pure copper plate and the carbon steel plate is ≤80 μm.

[0050] In the embodiment of the present application, before step S1, it includes: surface treatment of the core copper plate, the contact surface and the side of the outer steel plate to remove the surface oxide scale and control the surface roughness. Specifically, firstly, mechanical processing is used to remove the oxide scale on the four sides and contact surface of the copper plate and the steel plate; then the contact surface of the copper plate and the steel plate is rinsed and wiped with alcohol or acetone in turn. The surface roughness of the oxygen-free pure copper plate and the carbon steel plate after surface treatment is limited to effectively remove foreign matter on the surface, expose fresh metal, and make the copper-steel contact interface have better wettability. Exemplarily, the surface roughness Ra of the above-mentioned oxygen-free pure copper plate and carbon steel plate can be 80μm, 78μm, 76μm, 74μm, 72μm, etc.

[0051] Step S1 specifically includes: combining the size of the core copper plate and the steel plate, processing 4 side sealing frames, and welding and reinforcing them, the outer dimensions of the 4 sealing frames are consistent with the outer steel plate, the thickness is 30-60mm, the thickness is designed according to the thickness of the copper plate, and the narrow side is opened and welded into a rectangular frame. A sealed multi-layer copper-steel composite billet is formed by setting a frame structure between the outer carbon steel plates to completely cover the copper billet of the middle core layer, that is, the processed copper plate is placed in a sealing frame and combined with the outer steel plate to form a composite steel billet with a multi-layer copper-steel laminated structure, and the billet assembly is completed.

[0052] S2, vacuum welding the composite steel billet having a multi-layer copper-steel laminated structure to obtain a welded composite steel billet having a multi-layer copper-steel laminated structure;

[0053] In some embodiments, the process parameters of the vacuum welding include: vacuum degree, welding speed and welding beam current.

[0054] In some embodiments, the vacuum degree is ≤0.01 Pa.

[0055] In some embodiments, the welding speed is 100 mm / min to 310 mm / min, and the welding beam current is 40 mA to 320 mA.

[0056] In an embodiment of the present application, vacuum welding can be vacuum electron beam welding packaging or welding vacuum treatment, that is, welding and vacuuming are performed in no particular order. Step S2 specifically includes: placing the copper plate in a rectangular frame for welding packaging. For single-sided copper-steel composites, an isolation material is used between the two layers of copper plates, generally magnesium oxide; during welding, the beam spot position should be offset by 0.2-1mm to the copper plate side, and the focusing method adopts upper focusing. The above-mentioned vacuum degree is limited to avoid oxidation of the copper-steel interface due to residual oxygen during heating, thereby affecting the bonding effect. By limiting the above-mentioned welding speed and welding beam current, better weld structure and weld performance can be obtained. Exemplarily, the vacuum degree can be 0.01Pa, 0.009Pa, 0.008Pa, etc., the welding speed can be 100mm / min, 150mm / min, 200mm / min, 250mm / min, 300mm / min, 310mm / min, etc., and the welding beam current can be 40mA, 50mA, 60mA, 80mA, 100mA, 150mA, 200mA, 250mA, 300mA, 320mA, etc.

[0057] S3, subjecting the welded composite steel billet having a multi-layer copper-steel laminated structure to warm furnace heating, rolling and heat treatment to obtain a copper-steel composite plate.

[0058] In some embodiments, the heating temperature is 850° C. to 1060° C., and the holding time is 0.5 h to 3 h.

[0059] In the embodiment of the present application, the heating temperature and holding time are limited, and the temperature difference between the outer carbon steel and the inner copper layer is controlled so that the composite billet reaches a reasonable deformation and diffusion temperature range. If the temperature is too high, it may cause the copper to soften and melt, which is not conducive to rolling deformation and thickness control; if the temperature is too low, it may cause carbon steel to be difficult to deform and the diffusion effect to deteriorate, which is not conducive to deformation and composite effects. Exemplarily, the above-mentioned heating temperature can be 850℃, 860℃, 870℃, 880℃, 890℃, 1000℃, 1010℃, 1020℃, 1030℃, 1040℃, 1050℃, 1060℃, etc., and the holding time can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, etc. Specifically, the temperature charging furnace mode is adopted, and the welded composite steel with a multi-layer copper-steel laminated structure is placed in a heating furnace with the above-mentioned heating temperature and kept warm. After the surface temperature reaches the above-mentioned heating temperature, it is rolled out of the furnace.

[0060] In some embodiments, the rolling process parameters include:

[0061] Single pass deformation rate, total pass deformation rate, rolling rate and final rolling temperature; among which,

[0062] The deformation rate of a single pass is 4% to 15%, the deformation rate of the total pass is ≥50%, the rolling speed is 2m / s to 5m / s, and the final rolling temperature is

[0063] ≥750℃.

[0064] In the embodiment of the present application, rolling with multiple passes and small deformation is beneficial to deformation coordination; excessive single-pass deformation rate will cause excessive thinning of the copper layer and uneven thickness; too low single-pass deformation rate will lead to insufficient deformation penetration and poor bonding effect. Exemplarily, the above-mentioned single-pass deformation rate can be 4%, 6%, 8%, 10%, 12%, 14%, 15%, etc. Sufficient total compression deformation can obtain better bonding effect and reasonable plate width. Exemplarily, the above-mentioned total pass deformation rate can be 50%, 51%, 52%, 53%, etc. Suitable rolling speed is conducive to deformation coordination and composite strength control. Exemplarily, the above-mentioned rolling rate can be 2m / s, 3m / s, 4m / s, 5m / s, etc. While promoting the coordinated control of copper-steel deformation within the above-mentioned final rolling temperature range, the ideal toughness is obtained. Exemplarily, the above-mentioned final rolling temperature can be 750℃, 751℃, 752℃, 753℃, 754℃, etc.

[0065] The preparation method of the copper-steel composite plate is implemented based on the above-mentioned copper-steel composite plate. The specific structure of the copper-steel composite plate can refer to the above-mentioned embodiment. Since the preparation method of the copper-steel composite plate adopts part or all of the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0066] In view of the significant differences between copper and steel in thermal physical parameters such as thermal expansion and deformation resistance, under the conditions of large thickness ratio and multi-layer composite, there are problems such as extremely difficult control of billet assembly, rolling deformation and composite effect. The present application provides a copper-steel composite plate and a preparation method thereof, which has at least the following beneficial effects:

[0067] (1) The thick-gauge multi-layer copper-steel composite plate prepared by the embodiment of the present application has high bonding strength, and the interface bonding rate can reach 100%; this copper-steel composite plate can improve the strength of the thermal conductive structure without affecting the thermal conductive effect, and effectively improve the durability, safety and economy of the equipment.

[0068] (2) Through vacuum electron beam welding packaging or welding vacuum treatment, it is possible to effectively prevent air from oxidizing the copper-steel interface and improve the interface bonding quality. While improving the bonding effect, rolling deformation can also refine the copper plate grains to a certain extent and improve the thermal conductivity of the copper layer.

[0069] (3) Compared with the explosive welding composite method, the production efficiency and specification range of the composite plate are effectively improved, and environmental pollution and safety risks are reduced. The shape and size of the plate can be better controlled.

[0070] (4) The copper-steel composite plate has a strong metallurgical bond and a shear strength of ≥213MPa. It has the advantages of high efficiency, economy and continuous production, and can be promoted and applied in equipment such as blast furnace cooling walls and continuous casting crystallizers.

[0071] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0072] The present application provides a copper-steel composite plate. Please refer to Table 1 for the chemical composition of the copper-steel composite plate, and Table 2 for the composition and thickness of the copper-steel composite plate.

[0073] Table 1 Chemical composition of copper-steel composite plate (wt%), the rest is Fe and unavoidable impurities

[0074]

[0075] Table 2 Composition and thickness of copper-steel composite plate

[0076]

[0077] Based on the above steel-copper composite plate, the embodiment of the present application provides a method for preparing a steel-copper composite plate. Please refer to the preparation process parameters of the steel-copper composite plate shown in Table 3.

[0078] Table 3 Preparation process parameters of steel-copper composite plate

[0079]

[0080]

[0081] The copper-steel composite plate was subjected to various performance tests such as mechanical tensile and shear tests. Among them, the mechanical tensile performance was carried out in accordance with GB / T228-2010 Metal Material Tensile Test Room Temperature Test Method; the shear strength test was carried out in accordance with GB / T 6396-2008 Composite Steel Plate Mechanical and Process Performance Test Method, and the Z-direction tensile test was carried out in accordance with GB / T 5313 Thickness Direction Performance Steel Plate Related Test Methods. The specific test results are shown in Table 4.

[0082] Table 4 Mechanical properties of copper-steel composite plates

[0083]

[0084] It can be seen from Table 4 that the thick copper-steel composite plate provided in the embodiment of the present application has good structural strength and interface bonding strength, meets the yield strength ≥ 209 MPa, tensile strength ≥ 359 MPa, and shear strength ≥ 213 MPa, which is better than the mechanical properties of pure copper in Comparative Examples 1 to 2; Although the thick copper-steel composite plate obtained in Comparative Example 3 has excellent mechanical properties, it adopts an explosive composite combination method, has large interface stress, poor safety, prominent environmental protection issues, and is difficult to mass industrialize.

[0085] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A copper-steel composite plate, characterized in that: The copper-steel composite plate comprises an outer carbon steel plate and a core oxygen-free pure copper plate, and at least one side of the oxygen-free pure copper plate is entirely and continuously covered with the carbon steel plate; The chemical composition of the carbon steel plate includes: C, Si, Mn, Cr, Ni and Cu; wherein, in terms of mass fraction, The content of C is 0.05% to 0.20%, the content of Si is 0.1% to 0.55%, the content of Mn is 0.5% to 2.0%, the content of Cr is ≤1.0%, the content of Ni is ≤1.5%, and the content of Cu is ≤1.0%; The thickness of the copper-steel composite plate is 30 mm to 120 mm, and the ratio of the thickness of the oxygen-free pure copper plate to the thickness of the copper-steel composite plate is 0.4 to 0.

8.

2. The copper-steel composite plate according to claim 1, characterized in that: The chemical composition further includes at least one of the following: Mo and B; wherein the content of Mo is ≤0.5%, and the content of B is 0.0002% to 0.002%.

3. The copper-steel composite plate according to claim 1 or 2, characterized in that: The copper-steel composite plate meets the following mechanical properties: yield strength ≥ 209 MPa, tensile strength ≥ 359 MPa, and shear strength ≥ 213 MPa.

4. A method for preparing a copper-steel composite plate according to any one of claims 1 to 3, characterized in that: The method comprises: The oxygen-free pure copper plate and the carbon steel plate are combined to obtain a composite steel billet having a multi-layer copper-steel laminated structure; Vacuum welding the composite steel billet having a multi-layer copper-steel laminated structure to obtain a welded composite steel billet having a multi-layer copper-steel laminated structure; The welded composite steel billet with a multi-layer copper-steel laminated structure is subjected to warm furnace heating, rolling and heat treatment to obtain a copper-steel composite plate.

5. The method according to claim 4, characterized in that The process parameters of the vacuum welding include: vacuum degree, welding speed and welding beam current.

6. The method according to claim 4, characterized in that The vacuum degree is ≤0.01Pa.

7. The method according to claim 4, characterized in that The welding speed is 100 mm / min to 310 mm / min, and the welding beam current is 40 mA to 320 mA.

8. The method according to claim 4, characterized in that The heating temperature is 850° C. to 1060° C., and the insulation time is 0.5 h to 3 h.

9. The method according to claim 4, characterized in that The rolling process parameters include: Single pass deformation rate, total pass deformation rate, rolling rate and final rolling temperature; among which, The deformation rate of a single pass is 4% to 15%, the deformation rate of the total passes is ≥50%, the rolling rate is 2m / s to 5m / s, and the final rolling temperature is ≥750°C.

10. The method according to claim 4, characterized in that The surface roughness Ra of the oxygen-free pure copper plate and the carbon steel plate are both ≤80 μm.

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