A method for preparing continuous copper alloy strip

Abstract

The present invention relates to the technical field of copper alloy strip production, and more particularly to a continuous copper alloy strip production method, comprising: melting, casting, hot rolling, and milling a copper alloy raw material to obtain a copper alloy slab, wherein any copper alloy slab is used as a front slab; another copper alloy slab is selected as a rear slab, and the tail of the front slab and the head of the rear slab are cut; the cut end surfaces of the front slab and the rear slab are tightly spliced, and arc-starting blocks are abutted on both sides of the joint between the front and rear slabs; the joint between the front and rear slabs is friction stir welded; the joint after welding is cleaned to obtain a copper alloy weld plate; the copper alloy weld plate is used as the front slab, and the above steps are repeated to obtain a copper alloy slab coil; the copper alloy slab coil is uncoiled and cold rolled to obtain a continuous copper alloy strip. The present invention can achieve continuous production of copper alloy strip, significantly improving production efficiency, product yield, and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of copper alloy strip production, and in particular to a method for preparing a continuous copper alloy strip. Background Art

[0002] Copper alloy strips have excellent electrical and thermal conductivity and formability, making them widely used in the manufacture of components such as printed circuit boards, heat sinks, connectors, and connectors in the electronics, communications, automotive, and aerospace industries. However, compared to the continuous casting and rolling processes used for steel sheet and strip, the production process for copper alloy strips is less continuous. Because copper alloys oxidize more readily at high temperatures and their high thermal conductivity results in rapid cooling, ingot size is limited. Consequently, the length of hot-rolled slabs obtained through hot rolling is limited, hindering the efficiency of large-scale production of copper alloy strips. To improve the continuity of the copper alloy strip production process, multiple hot-rolled slabs can be joined together, increasing the length of strip required for subsequent continuous cold rolling and annealing processes, thereby improving production efficiency. By joining multiple hot-rolled slabs, longer continuous cold rolling and annealing steps can be achieved, reducing downtime and changeover time, and improving the operational stability and efficiency of the production line.

[0003] The current connection methods for hot-rolled copper alloy slabs mainly include mechanical connection and fusion welding. Among them, mechanical connection methods such as meshing have limited connection strength, and defects are easily generated at the connection during subsequent cold rolling and annealing, affecting production stability. Traditional welding methods such as arc welding have a large heat input, especially for thicker hot-rolled slabs (over 10mm), which requires a higher welding current, resulting in severe oxidation of the weld joint and more serious welding deformation, which in turn affects the plate shape of the hot-rolled slab and is not conducive to the subsequent cold rolling process. Although the heat input of laser welding is much lower than arc welding, the welding deformation is smaller, and the molten pool is protected by inert gas during the welding process, and the oxidation is relatively less serious, the absorption rate of copper and its alloys to lasers is extremely low (the absorption rate of solid copper to welding lasers with a wavelength of 1064nm is only 3-5%). Therefore, the welding of large-sized copper alloy thick plates requires extremely high laser power, and the equipment investment cost is very high. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing a continuous copper alloy strip.

[0005] The present invention adopts the following technical solution: a method for preparing a continuous copper alloy strip, the method comprising:

[0006] Step 1: Melting and casting the copper alloy raw material to generate a copper alloy ingot, and hot rolling and milling the copper alloy ingot in sequence to obtain a copper alloy slab, and any one of the copper alloy slabs is used as a front slab;

[0007] Step 2: Select another copper alloy slab that meets the dimensional error as the rear slab, place the front slab and the rear slab one after the other, and use a saw to cut the tail of the front slab and the head of the rear slab at a preset angle in sequence;

[0008] Step 3: tightly splice the cut end surface of the front slab and the cut end surface of the rear slab, use a preset arc-starting block to abut on both sides of the splicing seam between the front slab and the rear slab, and press and fix the tail of the front slab, the head of the rear slab and the arc-starting block;

[0009] Step 4: performing friction stir welding on the seam between the front slab and the rear slab, with the end point and the starting point of the friction stir welding being respectively on the arc-starting blocks on the left and right sides;

[0010] Step 5: cleaning the burrs and flash of the joint between the front slab and the rear slab after the friction stir welding, and removing the arc-starting blocks on the left and right sides to obtain a copper alloy welded plate;

[0011] Step 6: Using the copper alloy welding plate as a front slab, repeat steps 2 to 5 until the copper alloy welding plate reaches a target length, and coiling the copper alloy welding plate that has reached the target length to obtain a copper alloy slab coil;

[0012] Step seven: uncoiling the copper alloy slab coil, and sequentially performing rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing to obtain a continuous copper alloy strip.

[0013] A method for preparing a continuous copper alloy strip according to an embodiment of the present invention can avoid, to a certain extent, the influence of the adverse texture formed in the hot rolling process on the performance of the welded joint by cutting the tail of the front slab and the head of the rear slab at a preset angle, thereby improving the strength and toughness of the joint, and then connecting multiple copper alloy slabs together by stir friction welding, and then performing subsequent cold rolling, annealing and other processes, thereby realizing continuous production of copper alloy strips, greatly improving production efficiency, and improving product yield and stability; at the same time, compared with the traditional copper alloy slab connection method, the present invention adopts stir friction welding, a solid phase welding method, to avoid serious welding deformation and oxidation, and obtain a high-quality welded joint with strength and plasticity close to that of the parent material; and arc-starting blocks are used on both sides of the slab joint position during the welding process to ensure that the joints of the two copper alloy slabs are completely connected, and there is no need to cut the unwelded parts of the two side edges, only the arc-starting blocks need to be cut, which further ensures the product yield.

[0014] Furthermore, in step 1, the smelting temperature is between 1060°C and 1300°C, the casting temperature is between 1010°C and 1250°C, the preheating temperature of the hot rolling is between 720°C and 950°C, the final rolling temperature of the hot rolling is between 550°C and 750°C, and the reduction ratio of the hot rolling is between 80% and 95%.

[0015] Furthermore, the dimensional error includes a thickness error and a width error, wherein the thickness error is ±0.3 mm and the width error is ±20 mm.

[0016] Furthermore, the step of sequentially cutting the tail of the front slab and the head of the rear slab at a preset angle using a sawing machine specifically includes:

[0017] A sawing machine is used to cut the tail of the front slab and the head of the rear slab in sequence, wherein the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is between 10° and 20°, and the sawing machine cuts the front slab and the rear slab to the same size.

[0018] Furthermore, the composition of the arc-striking block is consistent with the composition of the front slab or the composition of the rear slab, and the thickness of the arc-striking block is consistent with the thickness of the front slab or the thickness of the rear slab.

[0019] Furthermore, when friction stir welding is performed on the joint between the front slab and the rear slab, the rotation speed of the stirring head is between 600 r / min and 1000 r / min.

[0020] Furthermore, when friction stir welding is performed on the joint between the front slab and the rear slab, the moving speed of the stirring head on the arc striking block is between 20 mm / min and 40 mm / min, and the moving speed of the stirring head on the joint between the front slab and the rear slab is between 100 mm / min and 120 mm / min.

[0021] Furthermore, in step seven, the reduction ratio of the rough rolling is between 70% and 90%, the temperature of the primary annealing is between 500° C. and 600° C., the holding time of the primary annealing is between 5 h and 8 h, the reduction ratio of the intermediate rolling is between 60% and 80%, the temperature of the secondary annealing is between 450° C. and 500° C., the holding time of the secondary annealing is between 5 h and 8 h, and the reduction ratio of the finishing rolling is between 10% and 50%;

[0022] Wherein, if the copper alloy strip is a soft strip, the temperature of the final annealing is 400° C. to 470° C., and the time of the final annealing is 5 h to 8 h;

[0023] If the copper alloy strip is a hard strip, the final annealing is not necessary. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0025] Figure 1 This is a flow chart of the method for preparing a continuous copper alloy strip of Example 1;

[0026] Figure 2 FIG1 is a process structure diagram of friction stir welding in Example 1;

[0027] Figure 3 Schematic diagram of the morphology and position of each region in the microstructure of the friction stir welded joint in Example 1;

[0028] Figure 4 The micro-Vickers hardness diagram of different areas of the friction stir welded joint in Example 1;

[0029] Figure 5 The microstructure morphology of different areas of the friction stir welded joint in Example 1;

[0030] Figure 6 Schematic diagram of the average grain size in different regions of the friction stir welded joint in Example 1;

[0031] Figure 7 This is a graph showing the tensile properties test results of the weld area of ​​the stir friction welding joint in Example 1. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0033] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0035] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0036] Example 1

[0037] Reference Figure 1 The first embodiment of the present invention is a method for preparing a continuous copper alloy strip, the method comprising:

[0038] S1: melting and casting a copper alloy raw material to generate a copper alloy ingot, and hot rolling and milling the copper alloy ingot in sequence to obtain a copper alloy slab, wherein any copper alloy slab is used as a front slab;

[0039] Furthermore, the copper alloy raw material is melted at a temperature of 1060°C to 1300°C and cast at a temperature of 1010°C to 1250°C; the preheating temperature of hot rolling is between 720°C and 950°C, the final rolling temperature of hot rolling is between 550°C and 750°C, and the reduction rate of hot rolling is between 80% and 95%.

[0040] In this embodiment, H65 brass is used as the copper alloy raw material, that is, H65 brass strip is finally prepared. Specifically, the H65 brass raw material is melted at a temperature of 1060°C to 1200°C, and then cast at 1010°C to 1080°C to produce an H65 brass ingot. The H65 brass ingot is then hot rolled and milled to obtain an H65 brass slab. The preheating temperature of the hot rolling is between 720°C and 900°C, the finishing temperature of the hot rolling is between 550°C and 700°C, and the reduction ratio of the hot rolling is 90%. In specific implementations, the reduction ratio of the hot rolling can also be 85%, 86%, 87%, 88%, 89%, etc., but is not limited to this.

[0041] S2: Select another copper alloy slab that meets the dimensional tolerance as the rear slab, place the front slab and the rear slab one after the other, and use a saw to cut the tail of the front slab and the head of the rear slab at a preset angle in sequence;

[0042] Furthermore, the dimensional error includes thickness error and width error, wherein the thickness error is ±0.3 mm and the width error is ±20 mm;

[0043] Furthermore, the steps of sequentially cutting the tail of the front slab and the head of the rear slab at a preset angle using a sawing machine specifically include:

[0044] A sawing machine is used to cut the tail of the front slab and the head of the rear slab in sequence, wherein the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is between 10° and 20°, and the sawing machine cuts the front slab and the rear slab to the same size; specifically, the sawing machine starts cutting along the right-angle end of the front slab and the rear slab, which can avoid the influence of the adverse texture formed in the hot rolling process on the performance of the welded joint to a certain extent, improve the strength and toughness of the joint, and fully consider saving materials and improving the yield rate of copper alloy strip products.

[0045] In this embodiment, the thickness of the H65 brass slab used as the front slab is 16.3 mm, the thickness of the H65 brass slab used as the first rear slab is 16.1 mm, the width of the front slab is 440.3 mm, the width of the rear slab is 445.5 mm, and the length of the stirring head for stir friction welding is 16.0 mm; the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is 18°. After cutting is completed, the front slab is controlled to move backward until it is in close contact with the rear slab to complete the splicing. The gap between the cut end faces of the front slab and the rear slab is controlled within 0.2 mm.

[0046] S3: The cut end face of the front slab is tightly joined with the cut end face of the rear slab, a preset arc-starting block is placed against both sides of the joint between the front slab and the rear slab, and the tail of the front slab, the head of the rear slab and the arc-starting block are pressed and fixed;

[0047] Furthermore, the composition of the arc-striking block is consistent with the composition of the front slab or the composition of the rear slab, and the thickness of the arc-striking block is consistent with the thickness of the front slab or the thickness of the rear slab; it can ensure that the joints of the two copper alloy slabs are completely connected, and there is no need to cut the unwelded parts of the two side edges, only the arc-striking block needs to be cut, which further ensures the product yield.

[0048] In this embodiment, H65 brass plates are selected as arc-starting blocks (two pieces on the left and right). The length of the arc-starting blocks is 120.5 mm, the width is 50.3 mm, and the thickness is 16.2 mm. The tail of the front slab to be welded, the head of the rear slab, and the arc-starting blocks are pressed downward, and at the same time, the left and right arc-starting blocks are close to the two sides of the slab and support them.

[0049] S4: Friction stir welding is performed on the joint between the front slab and the rear slab, with the end point and the starting point of the friction stir welding being on the arc starting blocks on the left and right sides respectively;

[0050] Furthermore, when friction stir welding is performed on the joint between the front slab and the rear slab, the rotation speed of the stirring head is between 600 r / min and 1000 r / min.

[0051] Furthermore, when friction stir welding is performed on the joint between the front slab and the rear slab, the moving speed of the stirring head on the arc striking block is between 20 mm / min and 40 mm / min, and the moving speed of the stirring head on the joint between the front slab and the rear slab is between 100 mm / min and 120 mm / min.

[0052] In this embodiment, friction stir welding is performed on the H65 brass slab (the joint between the front slab and the rear slab), and the starting and ending points of the welding are respectively on the left and right arc-striking blocks; the stirring head rotates at a high speed of 600 r / min on the arc-striking block, and starts to move to the other side after the stirring shoulder turns red. The moving speed on the arc-striking block is controlled at 30 mm / min, and the moving speed on the H65 brass slab is controlled at 100 mm / min.

[0053] S5: cleaning the burrs and flash of the joint between the front slab and the rear slab after the stir grinding welding, and removing the arc starting blocks on the left and right sides to obtain the copper alloy welded plate.

[0054] In this embodiment, after welding is completed, burrs and flash are cleaned and arc-starting blocks on both sides are removed to obtain an H65 brass welding plate.

[0055] S6: using the copper alloy welding plate as a front slab, repeating steps S2 to S5 until the copper alloy welding plate reaches a target length, and coiling the copper alloy welding plate that has reached the target length to obtain a copper alloy slab coil.

[0056] In this embodiment, after the H65 brass weld plate is repeatedly subjected to multiple friction stir welding processes and reaches a target length, it can be coiled to obtain an H65 brass sheet blank coil.

[0057] S7: uncoiling the copper alloy slab coil, and sequentially performing rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing to obtain a continuous copper alloy strip;

[0058] Furthermore, the reduction rate of rough rolling is between 80% and 90%, the temperature of the primary annealing is between 500° C. and 600° C., the holding time of the primary annealing is between 5 h and 8 h, the reduction rate of intermediate rolling is between 60% and 80%, the temperature of the secondary annealing is between 450° C. and 500° C., the holding time of the secondary annealing is between 5 h and 8 h, and the reduction rate of finishing rolling is between 10% and 50%;

[0059] Among them, if the copper alloy strip is a soft strip, the final annealing temperature is 400°C to 470°C, and the final annealing time is between 5h and 8h; if the copper alloy strip is a hard strip, no final annealing is required.

[0060] In this embodiment, the H65 brass slab coil is uncoiled and then subjected to rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing in sequence to obtain a continuous H65 brass strip. The rough rolling reduction ratio is 80%, the primary annealing temperature is between 500° C. and 550° C., the primary annealing holding time is 6.5 hours, the intermediate rolling reduction ratio is 60%, the secondary annealing temperature is between 450° C. and 500° C., the secondary annealing holding time is 6.5 hours, and the finish rolling reduction ratio is 30%. If the H65 brass strip required for production is a soft strip, the final annealing temperature is 420° C. to 470° C., and the final annealing time is 6.5 hours. If the H65 brass strip required for production is a hard strip, no final annealing is required. In specific implementation, the reduction rate of rough rolling can also be 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, etc., but not limited to this; the reduction rate of intermediate rolling can also be 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc., but not limited to this; the reduction rate of finish rolling can also be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 31%, 32%, 33%, 34%, 35%, etc., but not limited to this.

[0061] In this embodiment, the friction stir welding process is as follows Figure 2 As shown, the high-temperature stirring head is embedded in the H65 brass slab and moves along the joint line between the front slab and the rear slab, with the forward side being the front slab and the backward side being the rear slab; Figure 3The overall morphology of the H65 brass slab welded joint is similar to an inverted "Ω". It is found that the interface on the advancing side of the weld is obvious, while the interface on the retreating side is fuzzy. In addition, no obvious defects are found on the weld surface, indicating that the weld structure is relatively dense. Figure 4 It can be seen that the micro-Vickers hardness of different areas of the friction stir welded joint is higher than that of the H65 brass base material, weld nugget zone (WNZ): 96.7HV0.1; thermo-mechanical affected zone (TMAZ): 92.8HV0.1; heat affected zone (HAZ): 91.0HV0.1; base material zone (BM): 82.9HV0.1.

[0062] according to Figure 5 and Figure 6 It can be seen that, affected by the stirring action of the stirring head, the grain size of the weld nugget zone (WNZ) is significantly smaller than that of the other three areas. The grain sizes of the thermomechanically affected zone (TMAZ), heat-affected zone (HAZ) and base material zone (BM) increase in sequence. The average grain sizes of different areas are as follows: the weld nugget zone (WNZ) is 16.2 μm, the thermomechanically affected zone (TMAZ) is 23.2 μm, the heat-affected zone (HAZ) is 27.6 μm, and the base material zone (BM) is 46.6 μm.

[0063] Depend on Figure 7 It can be seen that the tensile strength of the H65 brass slab base material is 351MPa and the elongation is 63%, the tensile strength of the stir friction welded joint weld position is 339MPa and the elongation is 48%, both of which are similar to the base material; the stir friction welded joint position still does not crack or damage after cold rolling deformation with a reduction rate of more than 80%, the joint tensile strength is 372MPa and the elongation is 50%; the final strip yield can be increased by 5%, and the deviation of the tensile strength can be reduced by 10Mpa to 20Mpa.

[0064] The continuous copper alloy strip preparation method of the present invention can avoid the influence of the adverse texture formed in the hot rolling process on the performance of the welding joint to a certain extent by cutting the tail of the front slab and the head of the rear slab at a preset angle, thereby improving the strength and toughness of the joint, and then connecting multiple copper alloy slabs together by stir friction welding, and then performing subsequent cold rolling, annealing and other processes, thereby realizing continuous production of copper alloy strips, greatly improving production efficiency, and improving product yield and stability; at the same time, compared with the traditional copper alloy slab connection method, the present invention adopts stir friction welding, a solid phase welding method, to avoid serious welding deformation and oxidation, and obtain a high-quality welded joint with a strength and plasticity close to that of the parent material; and arc-starting blocks are used on both sides of the slab joint position during the welding process to ensure that the joints of the two copper alloy slabs are completely connected, and there is no need to cut the unwelded parts of the two side edges, only the arc-starting blocks need to be cut, which further ensures the product yield.

[0065] Example 2

[0066] In this embodiment, H70 brass is selected as the copper alloy raw material, that is, the final product is H70 brass strip; specifically, the H70 brass raw material is smelted at a temperature of 1100°C to 1300°C, and then cast at 1040°C to 1150°C to produce an H70 brass ingot; then the H70 brass ingot is sequentially hot rolled and milled to obtain an H70 brass slab; wherein, the preheating temperature of the hot rolling is between 800°C and 950°C, the finishing temperature of the hot rolling is between 550°C and 700°C, and the reduction ratio of the hot rolling is 95%. In specific implementation, the reduction ratio of the hot rolling can also be 90%, 91%, 92%, 93%, 94%, etc., but is not limited thereto.

[0067] In this embodiment, the thickness of the H70 brass slab used as the front slab is 16.5 mm, the thickness of the H70 brass slab used as the first rear slab is 16.2 mm, the width of the front slab is 440.1 mm, the width of the rear slab is 443.5 mm, and the length of the stirring head for stir friction welding is 16.2 mm; the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is 10°. After cutting is completed, the front slab is controlled to move backward until it is in close contact with the rear slab to complete the splicing. The gap between the cut end faces of the front slab and the rear slab is controlled within 0.2 mm.

[0068] In this embodiment, H70 brass plates are selected as arc-starting blocks (two pieces on the left and right). The length of the arc-starting blocks is 122.5 mm, the width is 51.2 mm, and the thickness is 16.3 mm. The tail of the front slab to be welded, the head of the rear slab, and the arc-starting blocks are pressed downward, and at the same time, the left and right arc-starting blocks are close to the two sides of the slab and support them.

[0069] In this embodiment, friction stir welding is performed on the H70 brass slab (the joint between the front slab and the rear slab), and the starting and ending points of the welding are respectively on the left and right arc-striking blocks; the stirring head rotates at a high speed of 800 r / min on the arc-striking block, and starts to move to the other side after the stirring shoulder turns red. The moving speed on the arc-striking block is controlled at 20 mm / min, and the moving speed on the H70 brass slab is controlled at 105 mm / min.

[0070] In this embodiment, after welding is completed, burrs and flash are cleaned and arc-starting blocks on both sides are removed to obtain an H70 brass welding plate.

[0071] In this embodiment, after the H70 brass weld plate is repeatedly subjected to multiple friction stir welding processes and reaches a target length, it can be coiled to obtain an H70 brass sheet blank coil.

[0072] In this embodiment, the H70 brass slab coil is unrolled, and then rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing are performed in sequence to obtain a continuous H70 brass strip, wherein the rough rolling reduction ratio is 70%, the primary annealing temperature is between 500°C and 600°C, the primary annealing holding time is between 5 hours, the intermediate rolling reduction ratio is 70%, the secondary annealing temperature is between 450°C and 500°C, the secondary annealing holding time is 5 hours, and the finish rolling reduction ratio is 10%; if the H70 brass strip required for production is a soft strip, the final annealing temperature is 430°C to 470°C, and the final annealing time is 5 hours; if the H70 brass strip required for production is a soft strip, the final annealing temperature is 430°C to 470°C, and the final annealing time is 5 hours; The H70 brass strip is a hard strip and does not require final annealing. In specific implementation, the reduction rate of rough rolling can also be 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc., but not limited to this; the reduction rate of intermediate rolling can also be 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc., but not limited to this; the reduction rate of finish rolling can also be 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc., but not limited to this.

[0073] Example 3

[0074] In this embodiment, T2 copper is selected as the copper alloy raw material, that is, T2 copper strip is finally prepared; specifically, the T2 copper raw material is smelted at a temperature of 1100°C to 1300°C, and then cast at 1100°C to 1250°C to produce a T2 copper ingot; then the T2 copper ingot is hot rolled and milled in sequence to obtain a T2 copper slab; wherein, the preheating temperature of the hot rolling is between 850°C and 950°C, the finishing temperature of the hot rolling is between 600°C and 750°C, and the reduction rate of the hot rolling is 80%. In specific implementation, the reduction rate of the hot rolling can also be 81%, 82%, 83%, 84%, 85%, etc., but is not limited to this.

[0075] In this embodiment, the thickness of a T2 copper slab used as the front slab is 15.8 mm, the thickness of the T2 copper slab used as the first rear slab is 15.6 mm, the width of the front slab is 440.2 mm, the width of the rear slab is 442.5 mm, and the length of the stirring head for stir friction welding is 15.5 mm; the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is 20°. After cutting is completed, the front slab is controlled to move backward until it is in close contact with the rear slab to complete the splicing. The gap between the cut end faces of the front slab and the rear slab is controlled within 0.2 mm.

[0076] In this embodiment, T2 copper plates are selected as arc-starting blocks (two pieces on the left and right). The length of the arc-starting blocks is 125.5 mm, the width is 50.2 mm, and the thickness is 15.8 mm. The tail of the front slab to be welded, the head of the rear slab, and the arc-starting blocks are pressed downward, and at the same time, the left and right arc-starting blocks are close to the two sides of the slab and support them.

[0077] In this embodiment, friction stir welding is performed on the T2 copper slab (the joint between the front slab and the rear slab), and the starting point and end point of the welding are respectively on the left and right arc-striking blocks; the stirring head rotates at a high speed of 1000r / min on the arc-striking block, and starts to move to the other side after the stirring shoulder turns red. The moving speed on the arc-striking block is controlled at 40mm / min, and the moving speed on the T2 copper slab is controlled at 120mm / min.

[0078] In this embodiment, after welding is completed, burrs and flash are cleaned and arc-starting blocks on both sides are removed to obtain a T2 copper welding plate.

[0079] In this embodiment, after the T2 copper welded plate is repeatedly subjected to friction stir welding and reaches a target length, it can be coiled to obtain a T2 copper plate blank coil.

[0080] In this embodiment, a T2 copper slab coil is uncoiled and then subjected to rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing in sequence to obtain a continuous T2 copper strip, wherein the rough rolling reduction ratio is 90%, the primary annealing temperature is between 500° C. and 600° C., the primary annealing holding time is between 8 hours, the intermediate rolling reduction ratio is 80%, the secondary annealing temperature is between 450° C. and 500° C., the secondary annealing holding time is 8 hours, and the finish rolling reduction ratio is 50%. If the T2 copper strip required for production is a soft strip, the final annealing temperature is between 400° C. and 450° C., and the final annealing time is 8 hours. If the T2 copper strip required for production is a hard strip, final annealing is not required; in specific implementation, the reduction rate of rough rolling can also be 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% and the like, but not limited thereto; the reduction rate of intermediate rolling can also be 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79% and the like, but not limited thereto; the reduction rate of finishing rolling can also be 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% and the like, but not limited thereto.

[0081] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0082] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a continuous copper alloy strip, characterized in that: The method comprises: Step 1: Melting and casting the copper alloy raw material to generate a copper alloy ingot, and hot rolling and milling the copper alloy ingot in sequence to obtain a copper alloy slab, and any one of the copper alloy slabs is used as a front slab; Step 2: Select another copper alloy slab that meets the dimensional error as the rear slab, place the front slab and the rear slab one after the other, and use a saw to cut the tail of the front slab and the head of the rear slab at a preset angle in sequence; Step 3: tightly splice the cut end surface of the front slab and the cut end surface of the rear slab, use a preset arc-starting block to abut on both sides of the splicing seam between the front slab and the rear slab, and press and fix the tail of the front slab, the head of the rear slab and the arc-starting block; Step 4: performing friction stir welding on the seam between the front slab and the rear slab, with the end point and the starting point of the friction stir welding being respectively on the arc-starting blocks on the left and right sides; Step 5: cleaning the burrs and flash of the joint between the front slab and the rear slab after the friction stir welding, and removing the arc-starting blocks on the left and right sides to obtain a copper alloy welded plate; Step 6: Using the copper alloy welding plate as a front slab, repeat steps 2 to 5 until the copper alloy welding plate reaches a target length, and coiling the copper alloy welding plate that has reached the target length to obtain a copper alloy slab coil; Step seven: uncoiling the copper alloy slab coil, and sequentially performing rough rolling, primary annealing, intermediate rolling, secondary annealing, finish rolling, and final annealing to obtain a continuous copper alloy strip.

2. The method for preparing a continuous copper alloy strip according to claim 1, wherein: In step 1, the smelting temperature is between 1060°C and 1300°C, the casting temperature is between 1010°C and 1250°C, the preheating temperature of the hot rolling is between 720°C and 950°C, the final rolling temperature of the hot rolling is between 550°C and 750°C, and the reduction ratio of the hot rolling is between 80% and 95%.

3. The method for preparing a continuous copper alloy strip according to claim 1, wherein: The dimensional error includes a thickness error and a width error, wherein the thickness error is ±0.3 mm and the width error is ±20 mm.

4. The method for preparing a continuous copper alloy strip according to claim 1, wherein: The steps of sequentially cutting the tail of the front slab and the head of the rear slab at a preset angle using a sawing machine specifically include: A sawing machine is used to cut the tail of the front slab and the head of the rear slab in sequence, wherein the horizontal angle between the running direction of the saw blade of the sawing machine and the width direction of the front slab or the rear slab is between 10° and 20°, and the sawing machine cuts the front slab and the rear slab to the same size.

5. The method for preparing a continuous copper alloy strip according to claim 1, wherein: The composition of the arc-striking block is consistent with the composition of the front slab or the composition of the rear slab, and the thickness of the arc-striking block is consistent with the thickness of the front slab or the thickness of the rear slab.

6. The method for preparing a continuous copper alloy strip according to claim 1, wherein: When friction stir welding is performed on the joint between the front slab and the rear slab, the rotation speed of the stirring head is between 600 r / min and 1000 r / min.

7. The method for preparing a continuous copper alloy strip according to claim 1, wherein: When friction stir welding is performed on the joint between the front slab and the rear slab, the moving speed of the stirring head on the arc striking block is between 20mm / min and 40mm / min, and the moving speed of the stirring head on the joint between the front slab and the rear slab is between 100mm / min and 120mm / min.

8. The method for preparing a continuous copper alloy strip according to claim 1, wherein: In step seven, the reduction ratio of the rough rolling is between 70% and 90%, the temperature of the primary annealing is between 500° C. and 600° C., the holding time of the primary annealing is between 5 hours and 8 hours, the reduction ratio of the intermediate rolling is between 60% and 80%, the temperature of the secondary annealing is between 450° C. and 500° C., the holding time of the secondary annealing is between 5 hours and 8 hours, and the reduction ratio of the finishing rolling is between 10% and 50%; Wherein, if the copper alloy strip is a soft strip, the temperature of the final annealing is 400° C. to 470° C., and the time of the final annealing is 5 h to 8 h; If the copper alloy strip is a hard strip, the final annealing is not necessary.

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