Rolling process for skew rolling hole pattern coated rolled piece of copper-clad aluminum bar

Abstract

The invention provides a rolling process of a skew rolling pass coated rolled piece of a copper-clad aluminum busbar, which comprises the following steps of: sequentially rolling a copper-clad aluminum continuous casting blank of which the processing incoming material is square back and forth through five passes of skew rolling passes with alternate positive and negative angles; and the rolled finished product copper-clad aluminum is obtained after two passes of box-type flat hole pattern back-and-forth rolling. According to the rolling technology based on the skew rolling pass, cracking of a copper layer and an aluminum core caused in the rolling process is avoided through pass cladding rolling, reverse rotation is not needed in the rolling process, and the production efficiency is effectively improved while the rolling speed is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of bimetallic composite materials, and specifically relates to a rolling process for a copper-clad aluminum bar with an inclined rolling pass for clad rolling pieces. Background Art

[0002] The copper-clad aluminum composite busbar is composed of a core aluminum and a clad copper layer, and its blank is made by a horizontal continuous casting direct composite forming technology. There are various processes for preparing composite materials in the prior art. For example, the invention patent with the application number 2013103040773 discloses a pass rolling process for a copper-clad aluminum bar. Although it can achieve fully enclosed constrained rolling, efficient area reduction, and solve the problem of separation of the bonding layer of the clad material, during each rolling process, the billet needs to be flipped, thus reducing the rolling efficiency of the copper-clad aluminum bar. Another example is the invention patent with the application number 2023102903505, which discloses an eight-pass pass continuous rolling process for a copper-clad aluminum bar. Specifically, the 1st, 3rd, 5th, and 7th rolling mills use flat rolling passes, and the 4th, 6th, and 8th rolling mills use vertical rolling passes for alternating flat and vertical rolling. Although it solves the problem of low rolling efficiency caused by billet flipping, during vertical rolling, since the overall reduction of copper and aluminum is greater than 30%, and because flat rolling and box pass rolling cannot limit the deformation of the copper layer around the copper-clad aluminum rolling piece, copper layer and aluminum layer cracking occur during the rolling process, especially during vertical rolling, damaging the copper-aluminum bonding interface. At the same time, if the box pass method continues to increase the restrictions on both sides of the pass, quality defects such as the copper layer "popping out" and "folding" from the roll gap will occur. Summary of the Invention

[0003] To solve the above technical problems, the present invention proposes a rolling process for a copper-clad aluminum bar with an inclined rolling pass for clad rolling pieces. In this process, the inclined rolling pass does not require reverse rolling, ensuring the stability of the rolling process and avoiding the problem of cracking of the copper-aluminum bonding layer caused by rolling.

[0004] According to the purpose of the present invention, a rolling process for a copper-clad aluminum bar with an inclined rolling pass for clad rolling pieces is proposed, including: passing a square-shaped copper-clad aluminum continuous casting billet through five passes of inclined rolling passes with alternating positive and negative angles for round-trip rolling, and then through two passes of box-shaped flat passes for round-trip rolling to obtain the rolled finished copper-clad aluminum.

[0005] Among them, the multi-pass inclined rolling passes with alternating positive and negative angles are set as follows: the first pass, the third pass, and the fifth pass all use negative-angle inclined rolling passes, and the second pass and the fourth pass both use positive-angle inclined rolling passes; the sixth pass and the seventh pass use box-shaped flat passes. The rolling speed for each pass is 20 - 60 m / min, and the pass slope of the inclined rolling pass is 10 - 25° / -10 - -25°.

[0006] Further, when rolling in the first pass, a square copper-clad aluminum continuous casting billet with a size of a * a mm is rolled into P1 with a height of a(1 - e) mm and a width of a(1 + r) mm. Here, e represents the absolute reduction rate in the first pass, and its value range is 20% - 38%. r represents the spread rate in the first pass, and its value range is -8% - 10%.

[0007] Further, when rolling in the second pass, P1 is rolled into P2 with a height of a(1 - e)(1 - t) mm and a width of a(1 + r)(1 + y) mm. Here, t represents the absolute reduction rate in the second pass, and its value range is 18% - 37%. y represents the spread rate in the second pass, and its value range is -8% - 10%.

[0008] Further, when rolling in the third pass, P2 is rolled into P3 with a height of a(1 - e)(1 - t)(1 - u) mm and a width of a(1 + r)(1 + y)(1 + i) mm. Here, u represents the absolute reduction rate in the third pass, and its value range is 16% - 35%. i represents the spread rate in the third pass, and its value range is -5% - 8%.

[0009] Further, when rolling in the fourth pass, P3 is rolled into P4 with a height of a(1 - e)(1 - t)(1 - u)(1 - v) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j) mm. Here, v represents the absolute reduction rate in the fourth pass, and its value range is 16% - 35%. j represents the spread rate in the first pass, and its value range is -5% - 8%.

[0010] Further, when rolling in the fifth pass, P4 is rolled into P5 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q) mm. Here, w represents the absolute reduction rate in the fifth pass, and its value range is 8% - 25%. q represents the spread rate in the fifth pass, and its value range is -5% - 8%.

[0011] Further, when rolling in the sixth pass, P5 is rolled into P6 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s) mm. Here, x represents the absolute reduction rate in the sixth pass, and its value range is 8% - 23%. s represents the spread rate in the sixth pass, and its value range is 0.1% - 5%.

[0012] Further, after rolling in the seventh pass, the rolled finished copper-clad aluminum is obtained. The dimensions of the finished copper-clad aluminum are as follows:

[0013] a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x)(1 - z) * a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s)(1 + k). Among them, z represents the absolute reduction rate of the seventh pass, and its value range is 5% - 23%. k represents the spread rate of the seventh pass, and its value range is 0.1% - 4%.

[0014] Furthermore, the fillet of the square copper - clad aluminum continuous casting billet is 10 mm, and the fillet of the finished copper - clad aluminum obtained after rolling is 2 mm.

[0015] Furthermore, the locking depth of the pass from the first pass to the sixth pass is 3.5 mm, the roll gap is 5 mm, the locking depth of the seventh - pass pass is 3 mm, and the roll gap is 3 mm.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) The rolling process of the present invention adopts a skew - rolling pass. During the rolling process, the pass can wrap and roll the rolled piece, and the deformation of the rolled piece is restricted and controllable.

[0018] (2) Instead of the flat - vertical alternating rolling, all passes adopt horizontal - pass rolling, avoiding the problem of copper - aluminum splitting caused by insufficient vertical rolling restriction of the pass.

[0019] (3) During the rolling process, flipping is not required, the rolling is stable, the rolling speed is increased, and the production efficiency is improved. At the same time, the contact area between the skew - rolling pass and the rolled piece is large, which is conducive to increasing the friction force and improving the biting condition. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the flat - pressing stress analysis of the box - type pass used in the prior art.

[0021] Figure 2 It is an embodiment diagram of the rolling process used in the prior art.

[0022] Figure 3 It is a schematic diagram of the stress analysis of the skew - rolling pass adopted by the present invention.

[0023] Figure 4 It is an embodiment diagram of the rolling process adopted by the present invention. Detailed Embodiments

[0024] The following further describes the present application in detail with reference to the drawings. It is necessary to point out here that the following detailed embodiments are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non - essential improvements and adjustments to the present application according to the above application content.

[0025] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the rolling process of the clad rolling piece of the existing copper-clad aluminum bar, box-type flat pass or flat-vertical pass alternating rolling is mostly adopted. However, in this way, the copper layer and the aluminum layer are prone to cracking during rolling, thus damaging the copper-aluminum bonding interface. As Figure 1 shown, it shows the flat pressure stress analysis process of the box pass adopted in the prior art. When the rolling mill applies a positive rolling force to the copper-clad aluminum rolling piece, the rolling piece generates lateral stresses, causing the rolling mill to spread during the rolling process. Since the spread coefficients of copper and aluminum are different under the same conditions, and the spread of both sides of the copper coating layer is not effectively restricted, the copper-aluminum bonding interfaces on both sides are damaged and cracking occurs. At the same time, if the restrictions on both sides of the pass are continuously increased in the box pass method, quality defects such as the copper layer "popping out" and "folding" from the roll gap will occur. Secondly, as Figure 2 shown, it shows the implementation method of the rolling process adopted in the prior art. During the rolling process, during the vertical rolling in the 2nd, 4th, 6th, and 8th passes, due to the shear stress applied by the vertical rolling to the side of the material and the insufficient restriction of the vertical pass on the material, the copper layer and the aluminum core are easily peeled off, damaging the copper-aluminum bonding interface.

[0027] For the above reasons, this embodiment provides a rolling process for the skew rolling pass clad rolling piece of a copper-clad aluminum bar. In this process, the skew rolling pass does not require reverse rolling, ensuring the stability of the rolling process and avoiding the problem of cracking of the copper-aluminum bonding layer caused by rolling.

[0028] As Figure 3 shown, this embodiment provides a design method for a skew rolling pass. The skew rolling pass can provide a wrapping roll pressure around it, ensuring that the rolling is wrapped around during the rolling process, without the copper layer and the aluminum core peeling off and without damaging the copper-aluminum bonding interface. And through this design method of the skew rolling pass, the rolling process for the skew rolling pass clad rolling piece of the copper-clad aluminum bar described above is realized, wherein the pass slope is 10 - 25° / -10 - -25°.

[0029] As Figure 4As shown, it shows the rolling process embodiment diagram adopted by the present invention. In this embodiment, the specific content of the rolling process is that the copper-clad aluminum continuous casting billet with a square shape as the processing material is successively subjected to back-and-forth rolling through the skew rolling pass with alternating positive and negative angles in five passes, and then through the box-shaped flat pass in two passes to obtain the rolled finished copper-clad aluminum. Among them, the rolling speed of each pass is 20 - 60 m / min.

[0030] In this embodiment, the first pass uses the 1# negative angle skew rolling pass to roll the square copper-clad aluminum continuous casting billet with dimensions of a * a mm into P1 with a height of a(1 - e) mm and a width of a(1 + r) mm. Here, e represents the absolute reduction rate of the first pass, and its value range is 20% - 38%. r represents the spread rate of the first pass, and its value range is -8% - 10%.

[0031] The second pass uses the 2# positive angle skew rolling pass. During rolling, P1 is rolled into P2 with a height of a(1 - e)(1 - t) mm and a width of a(1 + r)(1 + y) mm. Here, t represents the absolute reduction rate of the second pass, and its value range is 18% - 37%. y represents the spread rate of the second pass, and its value range is -8% - 10%.

[0032] The third pass uses the 3# negative angle skew rolling pass. During rolling, P2 is rolled into P3 with a height of a(1 - e)(1 - t)(1 - u) mm and a width of a(1 + r)(1 + y)(1 + i) mm. Here, u represents the absolute reduction rate of the third pass, and its value range is 16% - 35%. i represents the spread rate of the third pass, and its value range is -5% - 8%.

[0033] The fourth pass uses the 4# positive angle skew rolling pass. During rolling, P3 is rolled into P4 with a height of a(1 - e)(1 - t)(1 - u)(1 - v) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j) mm. Here, v represents the absolute reduction rate of the fourth pass, and its value range is 16% - 35%. j represents the spread rate of the first pass, and its value range is -5% - 8%.

[0034] The fifth pass uses the 5# negative angle skew rolling pass. During rolling, P4 is rolled into P5 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q) mm. Here, w represents the absolute reduction rate of the fifth pass, and its value range is 8% - 25%. q represents the spread rate of the fifth pass, and its value range is -5% - 8%.

[0035] In the sixth pass, a No. 6 box-type flat pass is adopted. During rolling, P5 is rolled into P6 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s) mm. Here, x represents the absolute reduction rate in the sixth pass, and its value range is 8% - 23%. s represents the spread rate in the sixth pass, and its value range is 0.1% - 5%.

[0036] In the seventh pass, rolling is carried out using a No. 7 box-type flat pass, and the finished copper-clad aluminum after rolling is obtained. The dimensions of the finished copper-clad aluminum are as follows:

[0037] a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x)(1 - z) * a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s)(1 + k)

[0038] In this embodiment, the dimension unit is millimeter, denoted by mm. That is, the height of the obtained finished copper-clad aluminum is a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x)(1 - z) mm, and the width of the obtained finished copper-clad aluminum is a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s)(1 + k) mm. Among them, z represents the absolute reduction rate in the seventh pass, and its value range is 5% - 23%. k represents the spread rate in the seventh pass, and its value range is 0.1% - 4%.

[0039] To more clearly describe the technical solution of this embodiment, various specific values shown in Table 1 are given to characterize the technical solution of the process provided in this embodiment.

[0040] Table 1. Rolling process parameters of a 60 * 60 mm square copper-clad aluminum continuous casting billet

[0041]

[0042] As shown in Table 1, when rolling in the first pass, a square copper-clad aluminum continuous casting billet with a size of 60*60 mm (in this embodiment, the value of a is 60) is rolled. The obtained P1 is 40*68 mm, the rolling speed is 20, and the pass slope is -15°. Then, after rolling in the second pass, P2 is obtained as 27*65 mm, the rolling speed is 25, and the pass slope is 15°. After P2 is rolled in the third pass, P3 is obtained as 19*63 mm, the rolling speed is 30, and the pass slope is -15°. Sequentially rolling, P4 is 13.5*60 mm, the rolling speed is 45, and the pass slope is 15°; P5 is 10*59 mm, the rolling speed is 50, and the pass slope is -15°; P6 is 8*59.5 mm, the rolling speed is 55; finally, the rolled finished copper-clad aluminum is 60*6 mm, the rolling speed is 60, that is, the size of the finally obtained finished product is 60*6 mm. At the same time, the fillet is 2 mm.

[0043] In the embodiment shown in Table 1, the finally obtained finished product size is 60*6 mm. The finished product with the required size can also be obtained by adjusting the roll gap, reduction, and reduction rate in Table 1. For example, based on the content of Table 1, when rolling in the first to sixth passes, the roll gap value is 5, and the roll gap value in the seventh pass is 3; the reductions in the first to seventh passes are 18, 13, 8, 5.5, 3.5, 2, and 2 respectively; the reduction rates are 30%, 31%, 27.6%, 26.2%, 22.6%, 16.7%, and 20% respectively. Then, the finished product size obtained after seven passes of rolling is 60*8 mm.

[0044] The rolling process of the skew rolling pass for clad rolling pieces provided by the present invention solves the problem of cracking of the bonding layer caused by different deformations and spreads due to different materials during the rolling process of copper-clad aluminum materials. At the same time, this rolling process does not require flipping the product after each pass of rolling. Therefore, the rolling is stable, the rolling speed is increased, and the production efficiency is improved. At the same time, negative spread rolling can be carried out with the skew rolling pass.

[0045] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A rolling process for a skew rolling pass clad workpiece of a copper-clad aluminum bar, characterized in that, The rolling process includes subjecting a square copper-clad aluminum continuous casting billet as the incoming material to reciprocating rolling through skew rolling passes with alternating positive and negative angles in five passes, and then to reciprocating rolling through box-shaped flat passes in two passes to obtain the rolled finished copper-clad aluminum. Among them, the skew rolling passes with alternating positive and negative angles in multiple passes are set as follows: the first pass, the third pass, and the fifth pass all adopt negative-angle skew rolling passes, and the second pass and the fourth pass both adopt positive-angle skew rolling passes; the sixth pass and the seventh pass adopt box-shaped flat passes. The rolling speed for each pass is 20 - 60 m / min, and the pass slope of the skew rolling pass is 10 - 25° / -10 - -25°.

2. The rolling process of the skew rolling pass-coated rolled piece according to claim 1, characterized in that, When rolling in the first pass, a square copper-clad aluminum continuous casting billet with dimensions of a * a mm is rolled into P1 with a height of a(1 - e) mm and a width of a(1 + r) mm. Here, e represents the absolute reduction rate in the first pass, and its value range is 20% - 38%. r represents the spread rate in the first pass, and its value range is -8% - 10%.

3. The rolling process of the skew rolling pass covering the rolled piece according to claim 2, characterized in that, When rolling in the second pass, P1 is rolled into P2 with a height of a(1 - e)(1 - t) mm and a width of a(1 + r)(1 + y) mm. Here, t represents the absolute reduction rate in the second pass, and its value range is 18% - 37%. y represents the spread rate in the second pass, and its value range is -8% - 10%.

4. The rolling process of the skew rolling pass covering the rolled piece according to claim 3, characterized in that, When rolling in the third pass, P2 is rolled into P3 with a height of a(1 - e)(1 - t)(1 - u) mm and a width of a(1 + r)(1 + y)(1 + i) mm. Here, u represents the absolute reduction rate in the third pass, and its value range is 16% - 35%. i represents the spread rate in the third pass, and its value range is -5% - 8%.

5. The rolling process of the skew rolling pass covering the rolled piece according to claim 4, characterized in that, When rolling in the fourth pass, P3 is rolled into P4 with a height of a(1 - e)(1 - t)(1 - u)(1 - v) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j) mm. Here, v represents the absolute reduction rate in the fourth pass, and its value range is 16% - 35%. j represents the spread rate in the first pass, and its value range is -5% - 8%.

6. The rolling process of the skew rolling pass covering the rolled piece according to claim 5, characterized in that, When rolling in the fifth pass, P4 is rolled into P5 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q) mm. Here, w represents the absolute reduction rate in the fifth pass, and its value range is 8% - 25%. q represents the spread rate in the fifth pass, and its value range is -5% - 8%.

7. The rolling process of the skew rolling pass covering the rolled piece according to claim 6, characterized in that, When rolling in the sixth pass, P5 is rolled into P6 with a height of a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x) mm and a width of a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s) mm. Here, x represents the absolute reduction rate in the sixth pass, and its value range is 8% - 23%. s represents the spread rate in the sixth pass, and its value range is 0.1% - 5%.

8. The rolling process of the skew rolling pass covering the rolled piece according to claim 7, characterized in that, After rolling in the seventh pass, the rolled finished copper-clad aluminum is obtained. The dimensions of the finished copper-clad aluminum are: a(1 - e)(1 - t)(1 - u)(1 - v)(1 - w)(1 - x)(1 - z) * a(1 + r)(1 + y)(1 + i)(1 + j)(1 + q)(1 + s)(1 + k) Among them, z represents the absolute reduction rate of the seventh pass, with a value range of 5% to 23%, and k represents the spread rate of the seventh pass, with a value range of 0.1% to 4%.

9. The rolling process of the skew rolling pass covering the rolled piece according to claim 8, characterized in that, The fillet of the square copper-clad aluminum continuous casting billet is 10 mm, and the fillet of the finished copper-clad aluminum obtained after rolling is 2 mm.

10. The rolling process of the skew rolling pass covering the rolled piece according to claim 8, characterized in that, The locking depth of the pass from the first pass to the sixth pass is 3.5 mm, the roll gap is 5 mm, the locking depth of the seventh pass is 3 mm, and the roll gap is 3 mm.

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