A method for preparing a thin-gauge copper-steel clad plate

Abstract

The application provides a preparation method of a thin-gauge copper-steel composite plate, comprising the following steps: step one, pretreating the strip steel; step two, spraying a uniform and dense copper metal layer on the surface of the strip steel through a spraying system; step three, completing double-side copper powder spraying of the strip steel; detecting the porosity of the sprayed copper layer after spraying; step four, performing rolling composite of the strip steel by using a multi-roller continuous rolling mill, and adopting pulse current assisted rolling in the rolling process; step five, realizing mechanical composite of the copper layer and the steel layer interface after the electric rolling, and then performing annealing treatment, so as to obtain the copper-steel composite plate. The application solves the heat treatment bulging phenomenon after the rolling composite of the copper plate and the steel plate, improves the cross-section bonding strength of the copper layer and the steel layer, the structure of the copper-steel composite plate has a longer service life, a large amount of valuable metal copper is saved, the cost is greatly reduced, and good economic benefits are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal composite forming, in particular, especially relates to a preparation method of thin-gauge copper-steel composite plate. BACKGROUND

[0002] The thin-gauge copper-steel composite plate not only has excellent lubricating performance and heat conduction performance of copper, but also has high strength and low cost of steel, and is widely used in the fields of electronics and copper metallurgy. The preparation method of the composite plate is usually to prepare the composite plate by explosion compounding and rolling compounding through composite strip or slab. The explosion instant reaction is short and too complex, so that the interface bonding rate is not high, and the bonding strength is unstable; at the same time, there is certain limitation for producing copper-steel composite plate with thick cladding. In addition, the productivity and yield of this method are low, and the environment is seriously polluted. In the process of hot rolling or cold rolling, the composite plate needs to produce large plastic deformation, which will cause large residual stress at the interface. In addition, during the mechanical bonding process of double-layer strip, it is impossible to avoid the gas and impurities wrapped in the environment. After high-temperature annealing treatment, the drumming phenomenon often occurs, and interface oxides are generated, which affects the interface bonding effect. SUMMARY

[0003] According to the above technical problems, a preparation method of thin-gauge copper-steel composite plate is provided. The present application provides a short-process copper-steel composite plate method in the atmospheric environment, which uses the method of protection atmosphere arc spraying metal copper, and then adopts auxiliary pulse current rolling + vacuum / protection atmosphere high-temperature diffusion annealing. The electric rolling is beneficial to ionize the gas ions and oxide ions in the loose copper layer on the surface during the rolling process, so as to avoid the problems of interface impurity oxidation and heat treatment drumming after compounding. The present application does not need to use high-vacuum equipment, effectively realizes the short-process thin-gauge copper / steel composite plate preparation, and provides a train of thought for preparing high-interface bonding quality metal laminated composite material.

[0004] The technical means adopted by the present application are as follows:

[0005] A preparation method of thin-gauge copper-steel composite plate, characterized in that it comprises the following steps:

[0006] Step one, pretreating the strip steel;

[0007] Step two, spraying a uniform and dense copper metal layer on the surface of the strip steel through a spraying system;

[0008] Step three, completing the double-sided copper powder spraying of the strip steel; detecting the porosity of the sprayed copper layer after spraying;

[0009] Step four, adopting a multi-roll continuous rolling mill to roll the strip steel, and adopting pulse current assisted rolling in the rolling process;

[0010] Step five, mechanical compounding of copper layer and steel layer interface after charged rolling, then annealing treatment, copper-steel composite plate is prepared.

[0011] Further, in the step one, the thickness of the original steel strip is 0.08-2mm, the width is 200-600mm, the steel strip is polished, the surface roughness of the polished steel strip is kept <30μm, the polished surface of the steel strip is cleaned by alcohol and acetone in turn, the steel strip is subjected to vacuum annealing treatment at 850-1100℃ for 2-6h.

[0012] Further, in the step two, the spraying method is a protective atmosphere arc spraying method, the constant pressure inert gas is used as the protective atmosphere in the spraying process to reduce the oxygen content in the loose copper layer after spraying; the constant pressure inert gas is nitrogen or argon.

[0013] Further, in the step two, the spraying raw material is a copper wire, the copper wire is pure copper or a copper-based material with copper as the matrix, the pure copper is brass, bronze or red copper, etc.

[0014] Further, in the step two, the spraying system is automatically controlled, the spraying atomization pressure is 0.1-0.6MPa, the spraying distance is 50-100mm, the spraying equipment is symmetrically distributed on both sides of the steel strip, the steel strip is moved at a constant speed in the spraying process to ensure the uniformity of the spraying, and the moving speed of the steel strip is 2-10mm / s.

[0015] Further, in the step three, the thickness of the single layer of the sprayed copper powder is 40-300μm.

[0016] Further, in the step three, the porosity of the sprayed copper layer after detection is <10%.

[0017] Further, in the step four, the continuous rolling compounding reduction is 10-40% of the total thickness after spraying, the deformation amount distribution of each roller is 3-15%, the pulse current for the pulse current assisted rolling is 20-150A, the frequency is 200-4000HZ, and the surface of the roller is a special treated non-conductive roller.

[0018] Further, the specific steps of the step five are as follows: mechanical compounding of the copper layer and the steel layer interface after charged rolling, atomic diffusion after high temperature annealing treatment again to realize metallurgical combination, the rolled blank is placed in a reducing atmosphere heat treatment furnace for annealing treatment, the annealing temperature is 500-650℃, the annealing time is 10-60min, after the heat preservation is finished, argon is passed to cool to room temperature, and then the furnace is discharged, and a copper-steel composite plate with good interface combination is obtained.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] 1. The preparation method of the thin-gauge copper-steel composite plate provided by the application solves the heat treatment bulging phenomenon after the copper plate and the steel plate are rolled and combined, improves the cross-section bonding strength of the copper layer and the steel layer, and improves the structure of the copper-steel composite plate manufacturing to have a longer service life, saves a large amount of precious metal copper, greatly reduces the cost, and has good economic benefits.

[0021] 2. The preparation method of the thin-gauge copper-steel composite plate provided by the application does not need to use high-vacuum equipment, effectively realizes the short-process thin-gauge copper / steel composite plate preparation, and provides a train of thought for preparing a metal layered composite material with high interface bonding quality.

[0022] 3. The preparation method of the thin-gauge copper-steel composite plate provided by the application solves the heat treatment bulging phenomenon after the copper plate and the steel plate are rolled and combined, improves the cross-section bonding strength of the copper layer and the steel layer, and improves the structure of the copper-steel composite plate manufacturing to have a longer service life, saves a large amount of precious metal copper, greatly reduces the cost, and has good economic benefits.

[0023] Based on the above reasons, the application can be widely popularized in the field of metal composite material forming. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor under the premise of not paying the creative labor.

[0025] Figure 1 The process flow chart of the application.

[0026] Figure 2 The surface graph after spraying brass of the application.

[0027] Figure 3 The surface graph after rolling + heat treatment of the application. DETAILED DESCRIPTION

[0028] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict. The application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0029] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one example embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a reference to the presence of a feature, step, operation, device, component and / or combinations thereof.

[0031] Unless specifically stated otherwise, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in the examples herein are not intended to limit the scope of the application. At the same time, it should be clear that the sizes of the various parts shown in the drawings are not drawn in proportion. The techniques, methods and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the authorized description. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0032] The purpose of the present application is to provide a short process copper-steel composite plate rolling composite method, and the metal copper powder spraying thickness, the original steel layer thickness, the auxiliary pulse current parameter, the rolling deformation and the post-rolling heat treatment mode are proposed, which mainly solves the problems of low copper layer and steel layer interface bonding strength under conventional composite and mechanical composite and post-rolling heat treatment bulging.

[0033] As shown in Figure 1 The present application provides a preparation method of thin-gauge copper-steel composite plate, which is a process method of copper powder spraying on the surface of steel strip and then rolling composite. The method comprises the following steps:

[0034] (1) Using the protective atmosphere arc spraying method, a uniform and dense copper metal layer is sprayed on the surface of the strip steel. The raw material for spraying is copper wire, and the copper wire is brass, bronze, red copper, pure copper or copper-based material with copper as the matrix.

[0035] (2) The spraying process uses constant pressure inert gas (nitrogen, argon) as the protective atmosphere to reduce the oxygen content in the loose copper layer after spraying.

[0036] (3) The spraying system adopts automatic control, the spraying atomization pressure is 0.1~0.6MPa, the spraying distance is 50~100mm, the spraying equipment is symmetrically distributed on both sides of the strip steel, and the strip steel moves at a constant speed during the spraying process to ensure the uniformity of the spraying, and the moving speed is 2~10mm / s.

[0037] (4) The original strip steel thickness is 0.08~2mm, the width is 200~600mm, the strip steel surface roughness is kept <30μm, the strip steel needs to be cleaned by polishing the surface with alcohol and acetone, and the strip material needs to be vacuum annealed at 850℃~1100℃ for 2~6h.

[0038] (5) The strip steel is sprayed with copper powder on both sides, and the single layer thickness of the sprayed copper layer is 40~300μm.

[0039] (6) The porosity of the sprayed copper layer after spraying is <10% after detection.

[0040] (7) Multi-roll continuous rolling mill is used for rolling and compounding, the rolling reduction is 10~40% of the total thickness after spraying, the deformation distribution of each roll is 3%~15%, pulse current auxiliary rolling is used during rolling, the pulse current is 20~150A, the frequency is 200~4000HZ, and the surface of the roll is a special treated non-conductive roll.

[0041] (8) After electric rolling, mechanical compounding of the copper layer and the steel layer interface is realized, and after high temperature annealing treatment, atomic diffusion is realized, and metallurgical bonding is realized. The rolled blank is placed in a reducing atmosphere heat treatment furnace for annealing treatment, the annealing temperature is 500~650℃, the annealing time is 10~60min, after the holding ends, argon is passed to cool to room temperature, and then taken out of the furnace. Finally, a copper-steel composite plate with good interface bonding is obtained.

[0042] The application of the present application solves the heat treatment bulging phenomenon after the rolling and compounding of the copper plate and the steel plate, improves the cross-section bonding strength of the copper layer and the steel layer, the structure of the copper-steel composite plate has a longer service life, and a large amount of valuable copper is saved, which greatly reduces the cost and has good economic benefits.

[0043] Example 1

[0044] A preparation method of a thin-gauge copper-steel composite plate, the specific operation steps are:

[0045] Step 1: Take 304 thin strip steel with thickness of 0.08 mm, width of 200 mm, and surface average roughness of 10 μm, and the thin strip steel is subjected to vacuum annealing treatment at 1000 ℃ for 6 h.

[0046] Step 2: The strip steel is placed in the middle of the electric arc spraying position, the upper and lower surfaces are 50 mm away from the spraying gun position, the strip steel moves at 10 mm / s, φ2 mm H90 brass wire is used under the atomization pressure of 0.1 MPa, and the single-sided thickness of the sprayed copper layer reaches 40 μm. Figure 2 The figure shows the surface of the sprayed brass.

[0047] Step 3: The porosity of the sprayed copper layer is 5% after detection.

[0048] Step 4: Multi-roll continuous rolling is adopted for rolling and compounding, the rolling reduction is 10% of the total thickness after spraying, the pass deformation distribution is according to “160 μm x 0.97 x 0.97 x 0.96”, pulse current auxiliary rolling is adopted in the rolling process, the pulse current is 20-50 A, and the frequency is 2000-4000 HZ.

[0049] Step 5: Mechanical compounding of the copper layer and the steel layer interface is realized after electric rolling, atomic diffusion is realized after high-temperature annealing treatment again, metallurgical bonding is realized, the rolled blank is placed in a reducing atmosphere heat treatment furnace for annealing treatment, the annealing temperature is 500 ℃, the annealing time is 60 min, after the heat preservation is completed, argon is passed to quickly cool to room temperature, and then the furnace is discharged, and finally the copper-steel composite plate with good interface bonding is obtained. As shown in Figure 3 The figure shows the surface after rolling + heat treatment.

[0050] Example 2

[0051] A preparation method of a thin-gauge copper-steel composite plate, and the specific operation steps are as follows:

[0052] Step 1: Take 304 thin strip steel with thickness of 2 mm, width of 600 mm, and surface average roughness of 20 μm, and the thin strip steel is subjected to vacuum annealing treatment at 1100 ℃ for 6 h.

[0053] Step 2: The strip steel is placed in the middle of the electric arc spraying position, the upper and lower surfaces are 50 mm away from the spraying gun position, the strip steel moves at 2 mm / s, φ2 mm H90 brass wire is used under the atomization pressure of 0.6 MPa, and the single-sided thickness of the sprayed copper layer reaches 300 μm.

[0054] Step 3: The porosity of the sprayed copper layer is 5% after detection.

[0055] Step 4: The rolling compound is carried out by using a multi-roll continuous rolling mill, the rolling compound reduction is 40% of the total thickness after spraying, the pass deformation distribution is according to "2600 μm x 0.97 x 0.97 x 0.96 x 0.95 x 0.95 x 0.91 x 0.91 x 0.89", the pulse current auxiliary rolling is used in the rolling process, the pulse current is 50-150 A, and the frequency is 200-2000 HZ.

[0056] Step 5: The mechanical compound of the copper layer and the steel layer interface is realized after the electrified rolling, the metallurgical combination is realized by atomic diffusion after the high-temperature annealing treatment again, the rolled blank is placed in a reducing atmosphere heat treatment furnace for annealing treatment, the annealing temperature is 650 DEG C, the annealing time is 10 min, after the heat preservation is finished, argon is passed to cool to room temperature, and then the furnace is discharged, and finally the copper-steel composite plate with good interface combination is obtained.

[0057] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a thin-gauge copper-steel composite plate, characterized in that, Includes the following steps: Step 1: Pre-treat the strip steel; Step 2: Apply a uniform and dense copper metal layer to the surface of the strip steel using a spraying system; Step 3: Complete the double-sided copper powder coating of the steel strip; test the porosity of the coated copper layer after coating. Step 4: The strip steel is rolled and compounded using a multi-roll continuous rolling mill, with pulsed current assisted rolling during the rolling process; Step 5: After electric rolling, the interface between the copper layer and the steel layer is mechanically combined. Electric rolling helps to ionize the gas ions and oxide ions in the loose copper layer during the rolling process. After annealing, a copper-steel composite plate is prepared. In step one, the original strip steel has a thickness of 0.08~2mm and a width of 200~600mm. The strip steel is polished, and the surface roughness of the polished strip steel is kept <30μm. The polished surface of the strip steel is cleaned with alcohol and acetone in sequence. The strip steel is then subjected to vacuum annealing treatment at 850℃~1100℃ for 2~6h. In step two, the spraying method is a protective atmosphere arc spraying method. The spraying process uses constant pressure inert gas as a protective atmosphere to reduce the oxygen content in the loose copper metal layer after spraying. In step two, the spraying system is automatically controlled, the spraying atomization pressure is 0.1~0.6MPa, the spraying distance is 50~100mm, and the strip steel moves at a constant speed during the spraying process to ensure the uniformity of the spraying. The strip steel moving speed is 2~10mm / s. In step three, the thickness of a single layer of sprayed copper powder is 40~300μm; In step three, the porosity of the sprayed copper layer is found to be <10% after testing. In step four, the pulse current for pulse current assisted rolling is 20~150A and the frequency is 200~4000HZ.

2. The method for preparing thin-gauge copper-steel composite plates according to claim 1, characterized in that, In step two, the constant-pressure inert gas is nitrogen or argon.

3. The method for preparing thin-gauge copper-steel composite plates according to claim 1 or 2, characterized in that, In step two, the spraying material is metallic copper wire, which is pure copper or copper-based material with copper as the base. The pure copper is brass, bronze or red copper.

4. The method for preparing thin-gauge copper-steel composite plates according to claim 1, characterized in that, In step two, the spraying equipment is symmetrically distributed on both sides of the strip steel.

5. The method for preparing a thin-gauge copper-steel composite plate according to claim 1, characterized in that, In step four, the continuous rolling composite reduction is 10-40% of the total thickness after spraying, the deformation of each roll is distributed as 3%-15%, and the roll surface is a specially treated non-conductive roll.

6. The method for preparing a thin-gauge copper-steel composite plate according to claim 1, characterized in that, The specific steps of step five are as follows: after electrified rolling, mechanical bonding of the copper layer and steel layer interface is achieved. After high-temperature annealing, metallurgical bonding is achieved through atomic diffusion. The rolled billet is placed in a reducing atmosphere heat treatment furnace for annealing at a temperature of 500~650℃ for 10~60min. After heat preservation, argon gas is passed through and the billet is rapidly cooled to room temperature before being removed from the furnace to obtain a copper-steel composite plate with good interfacial bonding.

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