Rolling process and production line of nanometer aluminum alloy strip

Abstract

The application provides a rolling process and production line of nano-aluminum alloy strip, and relates to the technical field of alloy material processing. The process comprises the following steps: heating a nano-aluminum ingot to a specified tapping temperature to obtain a blank; the blank enters a rough rolling process, the blank is rough-rolled and the blank temperature is monitored in real time; when the blank temperature is lower than a specified rough rolling temperature, the blank is supplemented with heat in an online heat preservation process, so that the blank temperature is greater than or equal to the specified rough rolling temperature; the rough rolling and the supplementary heating are repeatedly performed until the cross-sectional thickness of the blank is rolled to be less than or equal to a specified cross-sectional thickness; the rough-rolled blank is cooled; then, the blank enters a finish rolling process to be finish-rolled until the cross-sectional thickness of the blank is a target cross-sectional thickness, and the nano-aluminum alloy strip is obtained. In the repeated rough rolling process, the rough-rolled blank is supplemented with heat and heat preservation, so that cracks in the blank during the rough rolling process can be avoided, and the quality of the nano-aluminum alloy strip is ensured.

Description

Technical Field

[0001] This invention relates to the field of alloy material processing technology, and in particular to a rolling process and production line for nano-aluminum alloy strip. Background Technology

[0002] With the continuous development of modern aerospace, nuclear industry, transportation, and the 3C (Computer, Communication, Consumer Electronics) industry, higher requirements are being placed on the comprehensive performance of structural components, making nano-aluminum alloys the preferred solution. Introducing uniformly dispersed nanophases into aluminum and aluminum alloy matrices can effectively solve the hot cracking problem during the solidification process of high-strength aluminum alloys, improving the alloy yield. Simultaneously, the nanophases can also act as reinforcing phases, further enhancing the strength and plasticity of the aluminum alloy matrix. Therefore, nano-reinforced aluminum alloys represent a new direction for the future high-end aluminum alloy market.

[0003] Although nano-aluminum alloys possess higher strength than the original alloys, high-content nano-aluminum alloys, due to their increased strength, are more brittle and have reduced workability, making them prone to cracking during the rolling process. Currently, the rolling process involves preheating in a furnace. However, because the dimensions of the billet change after rolling, it cannot be returned to the furnace for reheating. Therefore, maintaining the billet temperature within the required range during repeated rolling is a pressing issue that needs to be addressed. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a rolling process and production line for nano-aluminum alloy strip, which solves the problem that nano-aluminum alloy billets are difficult to roll stably into nano-aluminum alloy plates and are prone to cracking in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides a rolling process for nano-aluminum alloy strip, comprising the following steps:

[0006] (1) Heating before rough rolling:

[0007] Nano-aluminum ingots are heated to a specified furnace exit temperature to obtain billets;

[0008] (2) Rough rolling and heat preservation:

[0009] The billet enters the rough rolling process, where the billet is rough rolled and the billet temperature is monitored in real time;

[0010] When the billet temperature is lower than the specified rough rolling temperature, the billet enters the heat preservation process for supplementary heating to make the billet temperature greater than or equal to the specified rough rolling temperature.

[0011] This process of rough rolling and supplemental heating is repeated until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness.

[0012] (3) Cooling and finishing rolling:

[0013] The billet after rough rolling is cooled; then it enters the finishing rolling process for finishing rolling until the cross-sectional thickness of the billet is the target cross-sectional thickness, thus obtaining the nano-aluminum alloy strip.

[0014] Optionally, the heat preservation process is performed after the rough rolling process.

[0015] Optionally, in step (2), 350 degrees Celsius ≤ the specified roughing temperature ≤ 520 degrees Celsius.

[0016] Optionally, in step (2), the roughing pass reduction rate is 2% to 50%, the roughing passes are 10 to 30, the edge rolling is 5 to 15, and the edge rolling amount per pass is 2 mm to 10 mm.

[0017] Optionally, a shearing process is provided after the heat preservation process, before the finishing rolling process, and after the finishing rolling process. The billet after rough rolling or the strip before finishing rolling enters the shearing process and the irregular head of the billet or strip is sheared. The edge trimming shear after the finishing rolling process removes the defective edges on both sides of the strip.

[0018] Optionally, the billet is cooled by air cooling or liquid cooling in step (3).

[0019] Optionally, in step (3), the finishing rolling process of the billet is carried out by a finishing mill, the temperature of the billet entering the finishing mill is 350℃~420℃, and the temperature of the billet exiting the finishing mill is 250℃~320℃.

[0020] This invention provides a rolling production line for nano-aluminum alloy strip, comprising a heating furnace, a roughing mill, an induction heating furnace, a cooling device, and a finishing mill arranged sequentially. The heating furnace is used to heat nano-aluminum ingots to obtain billets; the roughing mill is used to roll the billets; the induction heating furnace is used to heat and replenish the temperature of the billets during rolling; the cooling device is used to cool the billets; and the finishing mill is used to finish roll the billets.

[0021] The billet is repeatedly rough-rolled at the roughing mill and supplemented with heating at the induction heating furnace until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness.

[0022] Optionally, the rolling production line further includes vertical rolls disposed between the heating furnace and the roughing mill.

[0023] Optionally, a heavy-duty shear is provided between the roughing mill and the cooling device, a light-duty shear is provided between the cooling device and the finishing mill, and the edge trimming shear is provided after the finishing mill.

[0024] As described above, the rolling process and production line for nano-aluminum alloy strip of the present invention have the following beneficial effects: During the rough rolling process, when the temperature of the nano-aluminum alloy billet is lower than the specified rough rolling temperature, the billet is supplementarily heated and kept warm until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness. This reduces the hardness of the nano-aluminum alloy billet during rough rolling, facilitating rolling, and ensures the temperature of the billet, preventing cracks from appearing in the billet during rough rolling and ensuring the quality of the nano-aluminum alloy strip. Attached Figure Description

[0025] Figure 1 The diagram shown is a schematic diagram of a nano-aluminum alloy rolling production line according to an embodiment of the present invention.

[0026] Labeling Explanation: 1. Heating furnace; 2. Vertical roll; 3. Roughing mill; 4. Induction heating furnace; 5. Heavy-duty shear; 6. Material stacking platform; 7. Cooling device; 8. Light-duty shear; 9. Finishing mill; 10. Edge trimming shear; 11. Coiling machine. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] Please see Figure 1It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components relevant to the present invention and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. The structures, proportions, and sizes shown in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of the present invention, should still fall within the scope of the technical content disclosed in the present invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0029] This invention provides a rolling process for nano-aluminum alloy strip, comprising the following steps:

[0030] (1) Heating before rough rolling:

[0031] Nano-aluminum ingots are heated to a specified furnace exit temperature to obtain billets;

[0032] (2) Rough rolling and heat preservation:

[0033] The billet enters the rough rolling process, where the billet is rough rolled and the billet temperature is monitored in real time;

[0034] When the billet temperature is lower than the specified roughing temperature, the billet is supplemented by an online heat preservation process to make the billet temperature greater than or equal to the specified roughing temperature.

[0035] This process of rough rolling and supplemental heating is repeated until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness.

[0036] (3) Cooling and finishing rolling:

[0037] The billet after rough rolling is cooled; then it enters the finishing rolling process for finishing rolling until the cross-sectional thickness of the billet is the target cross-sectional thickness, thus obtaining the nano-aluminum alloy strip.

[0038] In one exemplary embodiment, the specified exit temperature is 5-10 degrees Celsius higher than the temperature at which the material enters the roughing mill 3. The specified exit temperature can be adjusted according to actual production needs.

[0039] In an exemplary embodiment, in step (2) above, 350 degrees Celsius ≤ the specified roughing temperature ≤ 520 degrees Celsius. In this embodiment, the initial roughing temperature of the billet entering the roughing mill 3 is 360 degrees Celsius to 520 degrees Celsius, and the final rolling temperature of the billet leaving the roughing mill 3 is 350 degrees Celsius to 450 degrees Celsius. When the billet temperature is below 350 degrees Celsius, the induction heating furnace 4 provides supplementary heating to the billet.

[0040] In an exemplary embodiment, in step (2) above, the reduction rate of the roughing pass is 2% to 50%, the number of rolling passes is 10 to 30, the edge rolling is 5 to 15, and the edge rolling amount per pass is 2 mm to 10 mm. The roughing process reduces the reduction rate while increasing the number of rolling passes, thus avoiding cracks in the billet during the rolling process.

[0041] In one exemplary embodiment, the specified cross-sectional thickness is 10 mm to 30 mm. The specified cross-sectional thickness can be adjusted according to actual production needs.

[0042] In an exemplary embodiment, a shearing process is provided after the heat preservation process, before the finishing rolling process, and after the finishing rolling process. The billet after rough rolling or the strip before finishing rolling enters the shearing process and the irregular head of the billet or strip is sheared. The edge trimming shear after the finishing rolling process removes the defective edges on both sides of the strip.

[0043] In an exemplary embodiment, the cooling of the billet in step (3) above is achieved by air cooling or liquid cooling. Air can be used directly for cooling, as it is abundant and economical; the liquid can be water or an emulsion, etc. The type of cooling liquid can be adjusted according to actual production needs.

[0044] In an exemplary embodiment, in step (3) above, the finishing rolling process of the billet is performed by a finishing mill 9. The temperature of the billet entering the finishing mill 9 is 350°C to 420°C, and the temperature exiting the finishing mill 9 is 250°C to 320°C. Cooling the billet before finishing rolling can reduce its temperature, making it more suitable for the finishing rolling process and preventing cracks from appearing in the billet during the finishing rolling process.

[0045] In one exemplary embodiment, the final thickness is 2mm to 8mm. The final thickness setting can be adjusted according to actual production needs.

[0046] In an exemplary embodiment, the rolling process further includes step (4), which involves coiling the finished nano-aluminum alloy strip into a roll. The coiled nano-aluminum alloy strip facilitates storage and transportation. Cooling the nano-aluminum alloy strip before coiling it prevents the strip from becoming too hot after coiling, which could lead to larger grains in the nano-aluminum alloy roll and affect the strength and quality of the nano-aluminum alloy plate.

[0047] This invention provides a rolling production line for nano-aluminum alloy strip, comprising a heating furnace 1, a roughing mill 3, an induction heating furnace 4, a cooling device 7, and a finishing mill 9 arranged sequentially. The heating furnace 1 heats nano-aluminum ingots to obtain a billet; the roughing mill 3 rolls the billet; the induction heating furnace 4 provides supplementary heating to the billet during rolling; the cooling device 7 cools the billet; and the finishing mill 9 performs finishing rolling on the billet. The billet is repeatedly rough-rolled at the roughing mill 3 and supplemented with heating at the induction heating furnace 4 until the cross-sectional thickness of the billet is rolled to be less than or equal to a specified cross-sectional thickness. The induction heating furnace 4, located after the roughing mill 3, allows for online heating of the billet, making the production process smoother. The induction heating furnace 4 on the rolling production line can provide online heating and heat preservation of the billet, preventing cracks from appearing during rough rolling due to temperature drop.

[0048] In an exemplary embodiment, the normally open mode of the induction heating furnace 4 is a low-heat mode. When the temperature of the billet is detected to be lower than the specified rough rolling temperature, the heating mode is turned on to heat the billet passing through the induction heating furnace 4.

[0049] In one exemplary embodiment, the cooling device 7 is a pipe with internal nozzles. When the billet passes through the pipe, a cooling medium is sprayed from the nozzles of the cooling device 7 to cool the billet. The cooling medium can be air, water, or an emulsion. A temperature sensor is installed inside the cooling device 7 to obtain the temperature of the billet, and the amount of cooling medium sprayed by the cooling device 7 can be increased or decreased based on the temperature.

[0050] In an exemplary embodiment, the rolling production line further includes a vertical roll 2, which is disposed between the heating furnace 1 and the induction heating furnace 4 along the conveying direction of the conveyor. The vertical roll 2 can perform side rolling on the billet, reducing the amount of trimming required in the later stage and reducing the amount of waste generated during the production of nano-aluminum alloys.

[0051] In one exemplary embodiment, a heavy-duty shear 5 is provided between the roughing mill 3 and the cooling device 7, a light-duty shear 8 is provided between the cooling device 7 and the finishing mill 9, and a trimming shear 10 is provided after the finishing mill 9. The heavy-duty shear 5 and the light-duty shear 8 can remove irregular heads of billets or strips, and the trimming shear 10 can remove undesirable edges on both sides of the strip.

[0052] In one exemplary embodiment, after the nano-aluminum alloy billet is formed, it needs to be rolled by a coiling machine 11 to roll the aluminum alloy strip into a coil shape for easy storage and transportation.

[0053] In one exemplary embodiment, a material unloading stacking platform 6 is also provided between the heavy-duty shear 5 and the cooling device 7. After rough rolling and heavy-duty shearing 5, the billet can be removed from the production line and used as a primary product.

[0054] Example 1:

[0055] The composition of 7075 aluminum alloy is Si: 0.40%, Fe: 0.50%, Cu: 1.5%, Mn: 0.30%, Mg: 2.5%, Cr: 0.24%, Zn: 5.4%, Ti: 0.20%, and Al: balance; with 0.5% nano-SiC reinforcing particles added by mass.

[0056] After 7075 aluminum alloy is melted, SiC reinforcing particles are added and thoroughly mixed, then cast into ingots with a thickness of 560 mm. The ingots are then sawed and milled before being heated in a furnace. The nano-aluminum ingot exits the furnace at 398℃ and is then rolled repeatedly on a roughing mill. The roughing reduction rate is 2%–50%, with 22 rolling passes and 12 edge rolling passes, with edge rolling amounts ranging from 2 mm to 10 mm per pass. Induction heating is used after the roughing mill to provide online temperature compensation for the billet, controlling the billet temperature above 380℃. Heavy-duty shears are used for head cutting during the roughing process. The rough-rolled aluminum plate is 14 mm thick. After cooling, the inlet rolling temperature of finishing mill 9 is 380℃. After passing through a light shear head, the billet passes through finishing mill 9, which has 4 stands. The cumulative reduction rate of finishing mill 9 is 74%, and the hot finishing rolling temperature is 300℃. After hot-rolled nano-aluminum alloy strips are trimmed and sheared, they are wound into coils by coiling machine 11.

[0057] In this embodiment, the finished nano-aluminum alloy strip has a thickness of 3.6 mm, a tensile strength of 598 MPa and a yield strength of 520 MPa in the T6 state, and no serious edge cracking or ingot cracking occurred during the rolling process. Therefore, the present invention can stably produce high-strength nano-aluminum alloys, and the produced nano-aluminum alloy plates have excellent performance.

[0058] Example 2:

[0059] The composition of 6061 aluminum alloy is Cu: 0.32%, Mn: 0.15%, Mg: 1.0%, Zn: 0.25%, Cr: 0.24%, Ti: 0.15%, Si: 0.56%, Fe: 0.2%, Al: balance; with added 1.5% nano-SiC reinforcing particles by mass.

[0060] After smelting 6061 aluminum alloy, SiC reinforcing particles are added and thoroughly mixed. The mixture is then cast into ingots with a thickness of 520 mm. After sawing and milling, the ingots are heated in a furnace. The nano-aluminum ingot exits the furnace at 485℃ and is then rolled repeatedly on a roughing mill. The roughing reduction rate is 2%–50%, with 18 rolling passes and 8 edge rolling passes, with an edge rolling amount of 2mm–6mm per pass. Induction heating is used after the roughing mill to provide online temperature compensation for the billet, controlling the billet temperature above 450℃. Heavy-duty shears are used for head cutting during roughing. The rough-rolled aluminum sheet is 13 mm thick. After cooling, the inlet rolling temperature of finishing mill 9 is 400℃. After passing through a light shear head, the billet passes through finishing mill 9, which has 4 stands. The cumulative reduction rate of finishing mill 9 is 70%, and the hot finishing rolling temperature is 310℃. After hot-rolled nano-aluminum alloy strips are trimmed and sheared, they are wound into coils by coiling machine 11.

[0061] In this embodiment, the finished nano-aluminum alloy strip has a thickness of 3.2 mm, a tensile strength of 320 MPa and a yield strength of 260 MPa in the T6 state, and no serious edge cracking or ingot cracking occurred during the rolling process. Therefore, the present invention can stably produce high-strength nano-aluminum alloys, and the produced nano-aluminum alloy plates have excellent performance.

[0062] Comparative Example 1:

[0063] The 7075 nano-aluminum alloy has the following composition: Si: 0.40%, Fe: 0.50%, Cu: 1.5%, Mn: 0.30%, Mg: 2.5%, Cr: 0.24%, Zn: 5.4%, Ti: 0.20%, and Al: balance; with 0.5% nano-SiC reinforcing particles added by mass.

[0064] After 7075 aluminum alloy is melted, SiC reinforcing particles are added and thoroughly mixed, then cast into ingots with a thickness of 540 mm. The ingots are then sawed and milled before being heated in a furnace. The nano-aluminum ingots exit the furnace at 390℃ and are then repeatedly rolled on a roughing mill. The roughing reduction rate is 2%–50%, and the edge rolling allowance is 2mm–10mm. Without induction heating, the temperature drops to 360℃ after the 10th pass, and cracking occurs in the rolled billet during the 12th pass, resulting in a defective product.

[0065] In this embodiment, no control measures were taken, and the billet cracked during the rolling process.

[0066] Comparative Example 2:

[0067] The 6061 nano-aluminum alloy has the following composition: Cu: 0.32%, Mn: 0.15%, Mg: 1.0%, Zn: 0.25%, Cr: 0.24%, Ti: 0.15%, Si: 0.56%, Fe: 0.2%, Al: balance; with the addition of 1.5% nano-SiC reinforcing particles by mass.

[0068] After smelting 6061 aluminum alloy, SiC reinforcing particles are added and thoroughly mixed. The mixture is then cast into ingots with a thickness of 550 mm. After sawing and milling, the ingots are heated in a furnace. The nano-aluminum ingots exit the furnace at 460℃ and are then repeatedly rolled on a roughing mill. The roughing reduction rate is 2%–50%, and the edge rolling allowance is 2mm–6mm. Without induction heating, the temperature drops to 370℃ after the 12th pass. By the 15th pass, the rolled billet shows edge cracking, resulting in a defective product.

[0069] In this embodiment, no control measures were taken, and the billet edge cracking occurred during the billet rolling process.

[0070] In summary, during the rough rolling process, when the temperature of the nano-aluminum alloy billet is lower than the specified rough rolling temperature, the billet is further heated until the cross-sectional thickness is rolled to be less than or equal to the specified cross-sectional thickness. This reduces the hardness of the nano-aluminum alloy billet during rough rolling, facilitating rolling, and ensures the billet temperature, preventing cracks from forming during rough rolling and guaranteeing the quality of the nano-aluminum alloy strip.

[0071] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A rolling process for nano-aluminum alloy strip, characterized in that, Includes the following steps: (1) Heating before rough rolling: Nano-aluminum ingots are heated to a specified furnace exit temperature to obtain billets; (2) Rough rolling and heat preservation: The billet enters the rough rolling process, where the billet is rough rolled and the billet temperature is monitored in real time; When the billet temperature is lower than the specified rough rolling temperature, the billet is supplemented by an online heat preservation process to make the billet temperature greater than or equal to the specified rough rolling temperature; This process of rough rolling and supplemental heating is repeated until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness. (3) Cooling and finishing rolling: The billet after rough rolling is cooled; then it enters the finishing rolling process for finishing rolling until the cross-sectional thickness of the billet is the target cross-sectional thickness, thus obtaining the nano-aluminum alloy strip. When the billet is supplemented with heating in the online heat preservation process, the low-heat mode in the heat preservation process is switched to the heating mode until the billet temperature is greater than or equal to the specified rough rolling temperature.

2. The rolling process for nano-aluminum alloy strip according to claim 1, characterized in that: The heat preservation process is followed by the rough rolling process.

3. The rolling process for nano-aluminum alloy strip according to claim 1 or 2, characterized in that: In step (2), 350 degrees Celsius ≤ the specified roughing temperature ≤ 520 degrees Celsius.

4. The rolling process for nano-aluminum alloy strip according to claim 1 or 2, characterized in that: In step (2), the reduction rate of the roughing pass is 2% to 50%, the number of roughing passes is 10 to 30, the number of rolling passes is 5 to 15, and the rolling amount per pass is 2 mm to 10 mm.

5. The rolling process for nano-aluminum alloy strip according to claim 1 or 2, characterized in that: A shearing process is set after the heat preservation process, before the finishing rolling process, and after the finishing rolling process. The billet after rough rolling or the strip before finishing rolling enters the shearing process and the irregular head of the billet or strip is sheared. The edge trimming shear after the finishing rolling process removes the defective edges on both sides of the strip.

6. The rolling process for nano-aluminum alloy strip according to claim 1, characterized in that: In step (3), the billet is cooled by air cooling or liquid cooling.

7. The rolling process for nano-aluminum alloy strip according to claim 1, characterized in that: In step (3), the finishing rolling process of the billet is carried out by a finishing mill. The temperature of the billet entering the finishing mill is 350℃~420℃, and the temperature of the billet exiting the finishing mill is 250℃~320℃.

8. A rolling production line for nano-aluminum alloy strip, characterized in that, The assembly includes, in sequence, a heating furnace, a roughing mill, an induction heating furnace, a cooling device, and a finishing mill. The heating furnace is used to heat nano-aluminum ingots to obtain billets; the roughing mill is used to roll the billets; the induction heating furnace is used to heat and replenish the temperature of the billets during rolling; the cooling device is used to cool the billets; and the finishing mill is used to finish roll the billets. The billet is repeatedly rough rolled at the roughing mill and supplemented with heating at the induction heating furnace until the cross-sectional thickness of the billet is rolled to be less than or equal to the specified cross-sectional thickness. The normally open mode of the induction heating furnace is the low-heat mode. When the temperature of the billet is detected to be lower than the specified rough rolling temperature, the heating mode is turned on to heat the billet passing through the induction heating furnace until the billet temperature is greater than or equal to the specified rough rolling temperature.

9. The rolling production line for nano-aluminum alloy strip according to claim 8, characterized in that, The rolling production line also includes vertical rolls, which are arranged between the heating furnace and the roughing mill.

10. The rolling production line for nano-aluminum alloy strip according to claim 8, characterized in that, A heavy-duty shear is installed between the roughing mill and the cooling device, a light-duty shear is installed between the cooling device and the finishing mill, and an edge-cutting shear is installed after the finishing mill.

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