Method for manufacturing aluminum core and aluminum core manufactured by method
By performing multi-step treatment of aluminum alloy billets, an aluminum core with improved strength and heat treatment performance was produced, which solved the problem that the existing aluminum tape core reduced strength after high-temperature annealing and difficult to achieve aluminum tape coil annealing treatment after slit, and achieved stability and pollution-freeness of the aluminum core and aluminum tape in high-temperature annealing treatment.
Patent Information
- Application Number
- CN202311675828.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-07
- Publication Date
- 2025-06-10
AI Technical Summary
The strength of the existing aluminum tape core decreases after high-temperature annealing and is prone to deformation, and it is difficult to achieve the slit aluminum tape annealing treatment, which easily leads to contamination and difficulty in taking out.
The aluminum alloy ingot is manufactured with improved strength and heat treatment performance through homogenization treatment, extrusion molding, quenching, artificial aging treatment, tension straightening, ruler processing and groove opening steps.
The aluminum core can maintain strength without deterioration during high-temperature annealing treatment, avoid deformation, and can be annealed with the aluminum tape to reduce pollution, and does not need to be taken out when scrapped and returned to the furnace, which meets product requirements.
Smart Images
Figure CN120115946A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of aluminum plate production and processing, and specifically, to a method for manufacturing an aluminum core and an aluminum core manufactured by this method. Background Art
[0002] During the manufacturing process of aluminum strips, wide-width aluminum strip coils usually need to be cut into narrow-width aluminum strips of the required width by a slitting machine and then rewound on a core to form narrow-width aluminum strip coils. In some cases, the cut narrow-width aluminum strip coils need to be annealed to form the required O-state (annealed state) aluminum strip products.
[0003] Existing cores are usually made of paper materials, steel, and rubber. Paper cores cannot withstand large curling tensions due to insufficient strength; and paper cores are easily affected by the environment. For example, in a relatively dry environment, the paper core dehydrates and its size becomes smaller, resulting in falling off from the aluminum strip coil; paper cores also cannot achieve the annealing treatment of the slit aluminum strip coils required by certain processes because the paper cores will burn due to high temperatures. Steel cores have a high cost, and when the slit aluminum strips need to be scrapped and remelted in a furnace, the steel cores need to be removed but it is difficult to remove them. Rubber cores not only have a high cost, but also cannot achieve the annealing treatment of the slit aluminum strip coils required by certain processes because the rubber cores will melt during high-temperature annealing; similarly, when the slit aluminum strips need to be scrapped and remelted in a furnace, the rubber cores need to be removed and it is difficult to remove them.
[0004] Some existing aluminum cores will cause a significant reduction in strength and deformation after high-temperature annealing, and the jelly formed by the melting of the tape used to bond the end of the aluminum strip coil and the outer surface of the aluminum core will overflow and contaminate the aluminum strip. Moreover, the inner surface of the existing aluminum cores is smooth, which may cause the aluminum strip coil to unwind and slip during use. Summary of the Invention
[0005] The present invention aims at the above problems existing in the prior art and provides a method for manufacturing an aluminum core and an aluminum core manufactured by this method.
[0006] The present invention provides a method for manufacturing an aluminum core using an aluminum alloy ingot. The aluminum core is used for winding the longitudinally cut aluminum strip and annealing together with the aluminum strip. The method sequentially includes the following steps:
[0007] Homogenization treatment: heating the aluminum alloy ingot to a first temperature higher than 550°C and holding for about 4 hours, then cooling to a second temperature lower than 550°C and holding for about 3 hours, then heating to a third temperature higher than 550°C and lower than the first temperature and holding for about 4 hours, and then successively cooling the aluminum alloy ingot to room temperature by air cooling and water cooling;
[0008] Extrusion forming: Heat the aluminum alloy ingot to a fourth temperature higher than 500 °C, place it in a mold with a temperature lower than 500 °C, and use an extrusion cylinder with a temperature lower than that of the mold to extrude the aluminum alloy ingot into a pipe.
[0009] Quenching: Perform on-line quenching on the pipe.
[0010] Artificial aging treatment: Place the pipe in an environment with a temperature of 165 °C to 175 °C for about 20 hours.
[0011] Tension straightening: Make the longitudinal deformation of the pipe 1.7% to 1.8%.
[0012] Cutting to length: Cut the pipe so that its width is less than the width of the aluminum strip.
[0013] According to a preferred embodiment of the present invention, the aluminum alloy ingot is made of an aluminum alloy containing the following elements by weight percentage: 0.7% to 0.75% of silicon, 0.15% to 0.2% of iron, 0 to 0.2% of copper, 0 to 0.3% of manganese, 0.52% to 0.58% of magnesium, 0 to 0.2% of chromium, 0 to 0.1% of zinc, and 0 to 0.1% of titanium.
[0014] According to a preferred embodiment of the present invention, the method further includes a grooving step. After the cutting to length, a plurality of circumferential grooves distributed axially are formed on the outer surface of the pipe.
[0015] According to a preferred embodiment of the present invention, the depth of each circumferential groove is about 2 mm, the width is about 5 mm, and the distance between adjacent circumferential grooves is about 20 mm.
[0016] According to a preferred embodiment of the present invention, in the homogenization treatment, the first temperature of the aluminum alloy ingot is about 580 °C, the second temperature is about 540 °C, and the third temperature is about 575 °C.
[0017] According to a preferred embodiment of the present invention, in the extrusion forming, the fourth temperature of the aluminum alloy ingot is 510 °C to 515 °C, the temperature of the mold is 480 °C to 490 °C, and the temperature of the extrusion cylinder is 410 °C to 420 °C.
[0018] According to a preferred embodiment of the present invention, the aluminum alloy ingot is extruded into a pipe with a thickness of about 5 mm.
[0019] According to a preferred embodiment of the present invention, in the quenching, the pipe is quenched on-line with a water mist having a temperature of 35 °C to 40 °C, and the pipe is cooled to about 200 °C at a cooling rate of less than 40 °C / minute.
[0020] According to a preferred embodiment of the present invention, in the artificial aging treatment, the temperature of the environment is about 170°C.
[0021] According to a preferred embodiment of the present invention, in the sizing treatment, the pipe is cut so that its width is about 1 mm narrower than the width of the aluminum strip.
[0022] According to a preferred embodiment of the present invention, in the extrusion molding, a plurality of axial protrusions distributed circumferentially are formed on the inner surface of the pipe.
[0023] On the other hand, the present invention also provides an aluminum core, which is manufactured by the method according to the above embodiments.
[0024] The aluminum core manufactured by the method of the present invention has improved yield strength, tensile strength, elongation, hardness, etc., and can therefore withstand a large coiling tension. When slitting the aluminum strip, a slitting process with a larger tension and slitting speed can be used to improve the coiling quality of the aluminum strip and avoid defects such as loose coiling and layer misalignment. In addition, due to the above improved properties, the aluminum core of the present invention can undergo high-temperature annealing treatment together with the aluminum strip wound thereon without deformation. On the other hand, since the outer surface of the aluminum core has a receiving groove, when the aluminum core and the aluminum strip coil undergo annealing treatment together, the glue formed after the melting of the tape used to bond the end of the aluminum strip coil and the outer surface of the aluminum core can be received in the receiving groove, thereby reducing or eliminating the contamination of the aluminum strip coil. When the aluminum strip coil needs to be scrapped, the aluminum core does not need to be taken out and can be remelted in the furnace together with the aluminum strip coil, and the chemical components with the selected content of the aluminum core can be diluted by the aluminum liquid to meet the product requirements of the aluminum strip. Description of the Drawings
[0025] The following drawings are only intended to illustrate and explain the present invention schematically. The dimensions and ratios in the drawings do not represent the dimensions and ratios of the actual products and do not limit the scope of the present invention. The drawings are only illustrative, and for the sake of clarity, some non-essential elements or features are omitted, and only the parts related to the present invention are schematically shown. They do not represent the actual structure of the products. In addition, for the sake of simplicity and easy understanding of the drawings, in some drawings, only one of the components with the same structure or function is schematically shown, or only one of them is marked, where:
[0026] Figure 1 Schematically shows a flowchart of a method for manufacturing an aluminum core according to a preferred embodiment of the present invention;
[0027] Figure 2 Schematically shows a three-dimensional view of an aluminum core manufactured by the method of the present invention;
[0028] Figure 3 Schematically shows Figure 2Side view of the aluminum core.
[0029] Reference numerals: 10 - aluminum core; 11 - receiving groove; 12 - reinforcing rib Detailed implementation manners
[0030] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed implementation manners of the present invention will now be described with reference to the accompanying drawings.
[0031] To simplify the drawings, only the parts related to the present invention are schematically shown in each drawing, and they do not represent the actual structure of the product. Additionally, for the sake of simplicity and easy understanding of the drawings, in some drawings, only one of the components with the same structure or function is schematically shown, or only one of them is labeled.
[0032] Figure 1 Schematically shown is a method for manufacturing an aluminum core according to a preferred embodiment of the present invention, which sequentially includes the following steps.
[0033] Homogenization treatment: First, place the aluminum alloy ingot in a heat treatment furnace and heat it to a first temperature above 550°C and hold for about 4 hours, and this temperature can be between 575°C and 585°C; then cool it to a second temperature below 550°C and hold for about 3 hours, and this temperature can be between 535°C and 545°C; then heat it again to a third temperature above 550°C and below the first temperature and hold for about 4 hours, and this temperature can be between 570°C and 580°C; after the ingot is taken out of the furnace, cool the aluminum alloy ingot to room temperature (i.e., ambient temperature, for example, it can be between 10°C and 30°C) by air cooling and water cooling in sequence. The coolants for air cooling and water cooling can be normal-temperature air and water. Through the above homogenization treatment, the magnesium silicide strengthening phase with a fine grain structure precipitates uniformly and can redissolve during the subsequent extrusion forming process to increase strength.
[0034] Extrusion forming: Heat the aluminum alloy ingot to a fourth temperature above 500°C, place it in a mold with a temperature below 500°C, and use an extrusion cylinder with a temperature lower than that of the mold to extrude the aluminum alloy ingot into a pipe. Through the above temperature setting, the extrusion performance and the high-temperature resistance performance of the extruded product can be ensured. Preferably, the fourth temperature of the aluminum alloy ingot is 510°C to 515°C, the temperature of the mold is 480°C to 490°C, and the temperature of the extrusion cylinder is 410°C to 420°C.
[0035] Quenching: Perform on-line quenching on the pipe. During this process, the magnesium silicide strengthening phase forms a supersaturated solid solution.
[0036] Artificial aging treatment: Place the said pipe in an environment with a temperature of 165°C to 175°C for about 20 hours, so that the magnesium silicide strengthening phase continues to precipitate, forming dispersed hard strengthening phase particles, which form resistance to dislocation cutting, thereby increasing the strength. Preferably, the temperature of the environment is 170°C.
[0037] Tension straightening: Make the longitudinal deformation of the said pipe be 1.7% to 1.8%. After tension straightening, the shape of the aluminum pipe is flat, the internal residual stress is reduced, and the strength is further enhanced.
[0038] Cutting to a fixed length: Cut the said pipe so that its width is less than the width of the aluminum strip, for the convenience of storing the aluminum strip coil. Preferably, make the width of the pipe about 1 mm narrower than the width of the aluminum strip.
[0039] In a preferred embodiment of the present invention, the aluminum alloy ingot is made of an aluminum alloy containing the following elements by weight percentage: 0.7% to 0.75% of silicon, 0.15% to 0.2% of iron, 0 to 0.2% of copper, 0 to 0.3% of manganese, 0.52% to 0.58% of magnesium, 0 to 0.2% of chromium, 0 to 0.1% of zinc, and 0 to 0.1% of titanium. The chemical composition within this selected range enables the aluminum core to have improved strength, so that it can be scrapped and recycled together with the cut aluminum strip, and its chemical composition can be diluted by the aluminum liquid to meet the product requirements of the aluminum strip.
[0040] According to an embodiment of the present invention, the method further includes a grooving step. After the cutting-to-fixed-length step, a plurality of circumferential receiving grooves distributed axially are formed on the outer surface of the pipe. When the cut aluminum strip needs to be annealed, the aluminum core of the present invention can be annealed together with the aluminum strip. During the annealing process, the gum generated by the melting of the tape used to bond the aluminum core and the aluminum strip can be received in the receiving grooves to reduce or avoid contaminating the aluminum strip. Preferably, the depth of each circumferential receiving groove is about 2 mm, the width is about 5 mm, and the spacing between adjacent circumferential grooves is about 20 mm.
[0041] In an embodiment of the present invention, in the homogenization treatment step, the first temperature of the aluminum alloy ingot is about 580°C, the second temperature is about 540°C, and the third temperature is about 575°C.
[0042] In an embodiment of the present invention, the aluminum alloy ingot is extruded into a pipe with a thickness of about 5 mm. In other embodiments, the thickness of the pipe can also be selected as other dimensions according to the size and stiffness requirements of the core, etc.
[0043] In an embodiment of the present invention, in the quenching step, an on-line quenching of the extruded pipe can be carried out using a water mist with a temperature of 35°C to 40°C, so that the pipe is cooled to about 200°C, and the cooling rate is preferably less than 40°C / minute.
[0044] In an embodiment of the present invention, in the extrusion molding step, a plurality of axially extending protrusions circumferentially distributed on the inner surface of the pipe can be formed simultaneously. On the one hand, the axially extending protrusions or rib structures can increase the strength of the core, and on the other hand, they can also prevent the core from slipping.
[0045] On the other hand, the present invention also provides an aluminum core for winding the slit aluminum strip. The aluminum core is manufactured by the method according to the above embodiments, has improved strength and heat treatment performance, and can therefore be annealed together with the aluminum strip.
[0046] As Figure 2 and Figure 3 shown, the aluminum core 10 of the present invention is an extruded cylindrical structure, and one or more grooves 11 extending circumferentially along the cylinder are integrally formed on its outer surface. The depth of each groove is about 2 mm and the width is about 5 mm. The plurality of grooves 11 are axially distributed along the cylinder, and the spacing between adjacent grooves is about 20 mm. The groove structure 11 can effectively accommodate the substances formed by the melting of the adhesive tape to reduce or eliminate the contamination of the aluminum strip product. In addition, in order to further increase the strength of the aluminum core and prevent slipping, a plurality of axially extending protrusion structures 12 or ribs 12 can also be integrally formed on the inner surface of the aluminum core 10 during the extrusion molding process. Figure 3 The protrusion structure 12 shown in Figure 3 is only exemplary. In addition to the generally rectangular cross-sectional shape shown in the figure, it can also be other various shapes such as arc-shaped, semi-circular, triangular, etc. Similarly, although
[0047] The aluminum core manufactured by the manufacturing method of the present invention has a yield strength of 250 to 260 Mpa at room temperature, a tensile strength of 280 to 290 Mpa, an elongation rate of 9 to 10%, and a hardness of 80 to 90 HB. Therefore, when slitting the aluminum strip, a slitting process with a large tension (such as 3300 N) can be used, thereby improving the coiling quality of the aluminum strip and avoiding defects such as loose coiling and layer misalignment. The slitting speed can also be increased from 300 m / min to 400 m / min. When annealing treatment is required for the aluminum strip after slitting in some process requirements, the aluminum core manufactured by the manufacturing method of the present invention can still meet the requirements in terms of strength at the annealing temperature (200 to 380 °C) without deformation. Specifically, in the temperature range of 200 to 280 °C, the strength of the aluminum core gradually decreases with the increase of temperature. The lowest yield strength of the aluminum core of the present invention in this temperature range can still reach 125 Mpa, and the lowest tensile strength can reach 150 Mpa; in the temperature range of 280 °C to below the melting point, the strength change range of the aluminum core is small. The lowest yield strength of the aluminum core of the present invention in this temperature range can reach 50 Mpa, and the lowest tensile strength can reach 92 Mpa, both of which are significantly higher than those of conventional aluminum cores. Therefore, it can pass through the annealing treatment together with the slitted aluminum strip without weakening and deforming. In addition, due to the selection of the content range of the chemical components contained in the aluminum core of the present invention, when the slitted aluminum strip needs to be scrapped and recycled due to quality and other problems, the aluminum core of the present invention can be recycled together with the aluminum strip, and its chemical components can be diluted by the aluminum liquid to meet the product requirements.
[0048] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0049] The above are only the illustrative specific embodiments of the present invention and are not intended to limit the scope of the present invention. The protection scope of the present invention is only defined by the claims. Benefiting from the teachings of the present invention, any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention also fall within the protection scope of the present invention.
Claims
1. A method for manufacturing an aluminum core, which is used for winding a longitudinally cut aluminum strip and annealing together with the aluminum strip. The method sequentially comprises the following steps: Homogenization treatment: heating an aluminum alloy ingot to a first temperature higher than 550 °C and holding for about 4 hours, then cooling to a second temperature lower than 550 °C and holding for about 3 hours, and then heating to a third temperature higher than 550 °C and lower than the first temperature and holding for about 4 hours, and then successively cooling the aluminum alloy ingot to room temperature by air cooling and water cooling; Extrusion molding: heating the aluminum alloy ingot to a fourth temperature higher than 500 °C, placing it in a mold with a temperature lower than 500 °C, and using an extrusion cylinder with a temperature lower than the temperature of the mold to extrude the aluminum alloy ingot into a pipe; Quenching: performing online quenching on the pipe; Artificial aging treatment: placing the pipe in an environment with a temperature of 165 °C to 175 °C for about 20 hours; Tension straightening: making the longitudinal deformation of the pipe be 1.7% to 1.8%; Cutting to length: cutting the pipe so that its width is less than the width of the aluminum strip.
2. The method according to claim 1, wherein, the aluminum alloy ingot is made of an aluminum alloy containing the following elements by weight percentage: 0.7% to 0.75% of silicon, 0.15% to 0.2% of iron, 0 to 0.2% of copper, 0 to 0.3% of manganese, 0.52% to 0.58% of magnesium, 0 to 0.2% of chromium, 0 to 0.1% of zinc, and 0 to 0.1% of titanium.
3. The method according to claim 2, wherein, the method further comprises a grooving step. After the cutting to length, a plurality of circumferential grooves distributed axially are machined on the outer surface of the pipe.
4. The method according to claim 3, wherein, the depth of each circumferential groove is about 2 mm, the width is about 5 mm, and the spacing between adjacent circumferential grooves is about 20 mm.
5. The method according to claim 2, wherein, in the homogenization treatment, the first temperature of the aluminum alloy ingot is about 580 °C, the second temperature is about 540 °C, and the third temperature is about 575 °C.
6. The method according to claim 5, wherein, in the extrusion molding, the fourth temperature of the aluminum alloy ingot is 510 °C to 515 °C, the temperature of the mold is 480 °C to 490 °C, and the temperature of the extrusion cylinder is 410 °C to 420 °C.
7. The method according to claim 6, wherein, the aluminum alloy ingot is extruded into a pipe with a thickness of about 5 mm.
8. The method according to claim 7, wherein, in the quenching, the pipe is subjected to online quenching with a water mist at a temperature of 35 °C to 40 °C, and the pipe is cooled to about 200 °C at a cooling rate of less than 40 °C / minute.
9. The method according to claim 8, wherein, in the artificial aging treatment, the temperature of the environment is about 170 °C.
10. The method according to claim 9, wherein, in the cutting to length, the pipe is cut so that its width is about 1 mm narrower than the width of the aluminum strip.
11. The method according to claim 2, wherein, in the extrusion molding, a plurality of axial protrusions distributed circumferentially are formed on the inner surface of the pipe.
12. An aluminum core, which is manufactured by the method according to any one of claims 1 to 11.