Aluminum alloy plate strip machining method

Abstract

According to the aluminum alloy plate strip machining method, the cold hardening technology of hot rolling, primary cold rolling and secondary cold rolling is adopted in sequence, so that the surface hardness of aluminum alloy is increased, and meanwhile the deep drawing and bending performance of the aluminum alloy can be effectively guaranteed; compared with an aluminum alloy plate strip machining method in the prior art, the product yield and the product performance can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy materials, and in particular to a method for processing an aluminum alloy plate strip. Background Art

[0002] Due to its many advantages such as good corrosion resistance, excellent weldability, good cold workability and high strength, aluminum alloy materials have been widely used in the manufacture of aircraft fuel tanks, oil pipes, sheet metal parts of transportation vehicles and ships, instruments, street lamp brackets and rivets, hardware products, and electrical housings.

[0003] During the processing of aluminum alloy sheets and strips in the prior art, while ensuring sufficient hardness, it is impossible to effectively guarantee their deep drawing and bending performance; at the same time, the yield rate of aluminum alloy sheets and strips in the prior art is relatively low.

[0004] Based on this, there is an urgent need to provide an aluminum alloy strip processing method to solve the defects and shortcomings in the above-mentioned prior art. Summary of the invention

[0005] In order to solve the defects and shortcomings in the above-mentioned prior art, the present invention proposes a method for processing aluminum alloy strips.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for processing an aluminum alloy strip, characterized in that it comprises the following steps: 1) Prepare raw materials: prepare raw materials according to the preset mass ratio of each element; 2) Melting and casting: The raw materials are melted and refined in sequence, then degassed and deslaged, and then cast into castings; 3) Evenly heat the casting: put the casting into the heating furnace to evenly heat and keep it warm, then cool it to room temperature; 4) Saw head milling: Saw off the heads at both ends of the casting and then mill the casting; 5) Hot rolling: hot rolling the aluminum alloy casting into aluminum alloy plates; 6) Intermediate annealing: intermediate annealing of the aluminum alloy sheet after hot rolling; 7) Initial cold rolling: the aluminum alloy sheet after intermediate annealing is then initially cold rolled to a preset first thickness range; 8) Edge trimming: Edge trimming of aluminum alloy sheets during the initial cold rolling process; 9) Secondary cold rolling: the trimmed aluminum alloy sheet is then subjected to secondary cold rolling to a preset second thickness range; 11) Quenching: quenching the cold alloy strip after foil rolling; 12) Aging: Send the strip after quenching treatment into the aging furnace; 13) Shearing: Shear the strip into finished products according to the required size; 14) Warehousing: After the finished products are inspected and qualified, they are packaged and put into storage.

[0007] As a further preferred embodiment of the present invention, in step 1), the mass fraction of each element satisfies: Si: 0.2-0.25%; Cu: 0.05-0.08%; Mg: 2.2-2.8%; Zn: 0.02-0.05%; Mn: 0.05-0.08%; Cr: 0.15-0.35%; Fe: 0.1-0.2%; The balance is Al.

[0008] As a further preferred embodiment of the present invention, in the step 2), the smelting temperature is 700-720°C, and the temperature is kept for 60-80 minutes; the refining temperature is 725-750°C, and the refining time is 1-2 hours.

[0009] As a further preferred embodiment of the present invention, in the step 2), the melt is degassed and deslaged by filling with an inert protective gas, and the inert protective gas is a mixture of at least one or more of helium, nitrogen or neon.

[0010] As a further preferred embodiment of the present invention, in step 3), the aluminum alloy casting is placed in a heating furnace, first heated to 500-520°C and kept warm for 2-4 hours, then heated to 550-580°C and kept warm for 8-10 hours, and then cooled to 520-530°C and kept warm for 2-4 hours.

[0011] As a further preferred embodiment of the present invention, in step 5), the aluminum alloy casting is subjected to 15-17 passes of rough hot rolling and three-stand hot finishing rolling to be an aluminum alloy plate with a thickness of 5 mm, the starting rolling temperature is 450-490°C, and the finishing rolling temperature is 310-330°C.

[0012] As a further preferred embodiment of the present invention, in step 6), the hot-rolled aluminum alloy sheet is sent to an annealing furnace for annealing at a temperature of 330-380° C. for 3-4 hours.

[0013] As a further preferred embodiment of the present invention, in step 7), the aluminum alloy sheet having a thickness of 5 mm is initially cold rolled into an aluminum alloy sheet having a first thickness range of 2-2.5 mm according to a thickness difference of 0.5-0.8 mm each time.

[0014] As a further preferred embodiment of the present invention, in step 9), the aluminum alloy sheet having a thickness of 2-2.5 mm is subjected to secondary cold rolling with a thickness difference of 0.2-0.5 mm each time to form an aluminum alloy sheet having a second thickness range of 1.5-1.8 mm.

[0015] As a further preferred embodiment of the present invention, in the step 12), after the foil is fed into the aging furnace, it is coiled at a temperature of 100-150°C. After the coiling is completed, the temperature of the coiled strip is reduced to room temperature at a cooling rate of 3-5°C / h.

[0016] Compared with the prior art, the advantages and positive effects achieved by the present invention include: 1) The present invention provides a method for processing aluminum alloy plates and strips. By sequentially adopting the cold working hardening processes of hot rolling, primary cold rolling and secondary cold rolling, the surface hardness of the aluminum alloy is increased, while its deep drawing and bending performance can be effectively guaranteed; compared with the aluminum alloy plate and strip processing method in the prior art, the product yield and product performance can also be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flowchart of the steps of an aluminum alloy strip processing method provided in this application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] [First embodiment] A first embodiment of the present invention provides an aluminum alloy strip processing method, comprising the following steps: 1) Prepare raw materials: Prepare raw materials according to the preset mass ratio of each element; in this embodiment, the mass fraction of each element satisfies: Si: 0.2-0.25%; Cu: 0.05-0.08%; Mg: 2.2-2.8%; Zn: 0.02-0.05%; Mn: 0.05-0.08%; Cr: 0.15-0.35%; Fe: 0.1-0.2%; The balance is Al; 2) Melting and casting: the raw materials are melted and refined in sequence, and then degassed and deslaged, and then cast into castings; the melting temperature in this embodiment is 700-720°C, and the temperature is kept for 60-80 minutes; the refining temperature is 725-750°C, and the refining time is 1-2 hours; at this time, the melt can also be degassed and deslaged by filling with inert protective gas, and the inert protective gas is a mixture of at least one or more of helium, nitrogen or neon; 3) Evenly heated: the casting is placed in a heating furnace for evenly heated and kept warm, and then cooled to room temperature; the specific operation steps of evenly heated in this embodiment are: the aluminum alloy casting is placed in a heating furnace, first heated to 500-520°C and kept warm for 2-4 hours, then heated to 550-580°C and kept warm for 8-10 hours, and then cooled to 520-530°C and kept warm for 2-4 hours; 4) Saw head milling: Saw off the heads at both ends of the casting, and then mill the casting to ensure that the surface of the casting is uniform; 5) Hot rolling: hot rolling the aluminum alloy casting into aluminum alloy plates; the specific process steps of hot rolling are: the aluminum alloy casting is subjected to 15-17 passes of rough hot rolling and three-stand hot finishing rolling to form an aluminum alloy plate with a thickness of 5mm, the starting rolling temperature is 450-490℃, and the final rolling temperature is 310-330℃; 6) Intermediate annealing: The aluminum alloy sheet after hot rolling is subjected to intermediate annealing; specifically, the aluminum alloy sheet after hot rolling is sent to an annealing furnace for annealing at a temperature of 330-380°C for 3-4 hours to further stabilize the sheet properties after hot rolling; 7) Primary cold rolling: the aluminum alloy sheet after intermediate annealing is subjected to primary cold rolling to a preset first thickness range; specifically, the aluminum alloy sheet with a thickness of 5 mm is subjected to primary cold rolling according to a thickness difference of 0.5-0.8 mm each time to form an aluminum alloy sheet with a first thickness range of 2-2.5 mm; In this process, as a preference, an aluminum alloy sheet with a thickness of 5 mm can be initially cold rolled into an aluminum alloy sheet with a first thickness range of 2-2.5 mm in a manner of decreasing thickness difference, and the sheet thickness can be adjusted after each initial cold rolling. For example, an aluminum alloy sheet with a thickness of 5 mm can be initially cold rolled with thickness differences of 0.8 mm, 0.7 mm, 0.6 mm and 0.5 mm in sequence to finally be formed into an aluminum alloy sheet with a first thickness range of 2.4 mm. This arrangement is due to: on the one hand, as the cold rolling forming is gradually carried out, the thickness of the aluminum alloy sheet decreases; on the other hand ... It will gradually become difficult, so the method of decreasing the thickness difference is more conducive to the forming of the aluminum alloy sheet; at the same time, the method of decreasing the thickness difference can facilitate the exposure of possible defects and problems of the aluminum alloy sheet during the cold rolling forming process through large thickness changes in the early and middle stages, and is also conducive to the corresponding and timely adjustment of the process parameters of the cold rolling forming. The corresponding process parameters of the cold rolling forming can be adjusted accordingly according to the initial and final thickness parameters of the aluminum alloy sheet during each cold rolling forming; in addition, the method of decreasing the thickness difference is also more conducive to the uniform composition and stable performance of the aluminum alloy sheet.

[0022] 8) Edge trimming: During the initial cold rolling process, the aluminum alloy sheet is trimmed to remove burrs and slag inclusions on both sides of the aluminum alloy sheet; 9) Secondary cold rolling: the trimmed aluminum alloy sheet is then subjected to secondary cold rolling to a preset second thickness range; the aluminum alloy sheet is subjected to secondary cold rolling according to a thickness difference of 0.2-0.5 mm each time, and the aluminum alloy sheet with a thickness of 2-2.5 mm is formed into an aluminum alloy sheet with a second thickness range of 1.5-1.8 mm; by sequentially adopting the cold working hardening process of hot rolling, primary cold rolling and secondary cold rolling, the surface hardness of the aluminum alloy is increased, and at the same time, its deep drawing and bending performance can be effectively guaranteed; compared with the aluminum alloy sheet and strip processing method in the prior art, the product yield and product performance can also be effectively improved; Similarly, in this process, as a preference, an aluminum alloy sheet with a thickness of 2-2.5 mm can be initially cold rolled into an aluminum alloy sheet with a first thickness range of 1.5-1.8 mm in a manner of decreasing thickness difference, and the sheet thickness can be adjusted after each initial cold rolling. For example, an aluminum alloy sheet with a thickness of 2.5 mm can be successively cold rolled with thickness differences of 0.5 mm, 0.3 mm and 0.2 mm to finally be formed into an aluminum alloy sheet with a second thickness range of 1.5 mm. This arrangement is because: on the one hand, as the cold rolling forming is gradually carried out, the thickness of the aluminum alloy sheet decreases. It will gradually become difficult to reduce the degree, so the method of decreasing the thickness difference is more conducive to the forming of the aluminum alloy plate; at the same time, the method of decreasing the thickness difference can facilitate the exposure of possible defects and problems of the aluminum alloy plate during the cold rolling forming process through large thickness changes in the early and middle stages, and is also conducive to the corresponding and timely adjustment of the process parameters of the cold rolling forming. The corresponding process parameters of the cold rolling forming can be adjusted accordingly according to the initial and final thickness parameters of the aluminum alloy plate during each cold rolling forming; in addition, the method of decreasing the thickness difference is also more conducive to the uniform composition and stable performance of the aluminum alloy plate.

[0023] Furthermore, the number of times the thickness difference decreases during the secondary cold rolling process should be lower than the number of times the thickness difference decreases during the primary cold rolling process. This is because, on the one hand, the secondary cold rolling is close to the final forming process of the aluminum alloy sheet, and the frequency of changes in the sheet thickness needs to be reduced as much as possible to ensure the stability of the performance of the finished product; on the other hand, the change in the thickness difference during the secondary cold rolling process is relatively low, so the adjustment accuracy of the working parameters is required to be high each time, and the adjustment process is relatively difficult. For example, for the adjustment of the spacing parameters of the rolling rollers, the more times the corresponding working parameters are adjusted according to the number of times the thickness difference decreases, the more the control process and time, and the lower the accuracy stability after adjustment. Therefore, it is necessary to reduce the frequency of changes in the sheet thickness during the secondary cold rolling process as much as possible; Correspondingly, the conveying speed of the aluminum alloy strip during the secondary cold rolling process can be set to be slower than the conveying speed of the aluminum alloy strip during the primary cold rolling process. The slower conveying speed can ensure the cold rolling process to be sufficient and comprehensive, and ensure that the thickness of the aluminum alloy strip in the overall conveying direction is uniform and stable. On the other hand, it is also conducive to the uniform composition and stable performance of the aluminum alloy strip before and after cold rolling. 10) Quenching: quenching the cold alloy strip after foil rolling; 11) Aging: Send the strip after quenching treatment into the aging furnace; 12) Shearing: Shear the strip into finished products according to the required size; after the foil is sent into the aging furnace, the strip is wound at a temperature of 100-150℃. After the winding is completed, the temperature of the wound strip is reduced to room temperature at a cooling rate of 3-5℃ / h; 13) Warehousing: After the finished products are inspected and found to be qualified, they are packaged and put into storage.

[0024] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for processing an aluminum alloy strip, characterized in that: The following steps are involved: 1) Prepare raw materials: prepare raw materials according to the preset mass ratio of each element; 2) Melting and casting: The raw materials are melted and refined in sequence, then degassed and deslaged, and then cast into castings; 3) Evenly heat the casting: put the casting into the heating furnace to evenly heat and keep it warm, then cool it to room temperature; 4) Saw head milling: Saw off the heads at both ends of the casting and then mill the casting; 5) Hot rolling: hot rolling the aluminum alloy casting into aluminum alloy plates; 6) Intermediate annealing: intermediate annealing of the aluminum alloy sheet after hot rolling; 7) Initial cold rolling: the aluminum alloy sheet after intermediate annealing is then initially cold rolled to a preset first thickness range; 8) Edge trimming: Edge trimming of aluminum alloy sheets during the initial cold rolling process; 9) Secondary cold rolling: the trimmed aluminum alloy sheet is then subjected to secondary cold rolling to a preset second thickness range; 10) Quenching: quenching the cold alloy strip after foil rolling; 11) Aging: Send the plate and strip after quenching treatment into the aging furnace; 12) Shearing: Shear the strip into finished products according to the required size; 13) Warehousing: Check the finished products and pack them for warehousing.

2. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In step 1), the mass fraction of each element satisfies: Si: 0.2-0.25%; Cu: 0.05-0.08%; Mg: 2.2-2.8%; Zn: 0.02-0.05%; Mn: 0.05-0.08%; Cr：0.15-0.35%； Fe: 0.1-0.2%; The balance is Al.

3. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 2), the melting temperature is 700-720°C and the temperature is kept for 60-80 minutes; the refining temperature is 725-750°C and the refining time is 1-2 hours.

4. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 2), the melt is degassed and deslagging is performed by filling with an inert protective gas, wherein the inert protective gas is a mixture of at least one or more of helium, nitrogen or neon.

5. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 3), the aluminum alloy casting is placed in a heating furnace, first heated to 500-520°C and kept warm for 2-4 hours, then heated to 550-580°C and kept warm for 8-10 hours, and then cooled to 520-530°C and kept warm for 2-4 hours.

6. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 5), the aluminum alloy casting is subjected to 15-17 passes of rough hot rolling and three-stand hot finishing rolling to be an aluminum alloy plate with a thickness of 5 mm, with a starting rolling temperature of 450-490°C and a finishing rolling temperature of 310-330°C.

7. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 6), the hot-rolled aluminum alloy sheet is sent to an annealing furnace for annealing at a temperature of 330-380° C. for 3-4 hours.

8. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 7), the aluminum alloy sheet having a thickness of 5 mm is initially cold rolled into an aluminum alloy sheet having a first thickness range of 2-2.5 mm according to a thickness difference of 0.5-0.8 mm each time.

9. The method for processing an aluminum alloy strip according to claim 1, characterized in that: In the step 9), the aluminum alloy sheet having a thickness of 2-2.5 mm is subjected to secondary cold rolling with a thickness difference of 0.2-0.5 mm each time to form an aluminum alloy sheet having a second thickness range of 1.5-1.8 mm.

10. The aluminum alloy strip processing method according to claim 1, characterized in that: In the step 12), after the foil is sent into the aging furnace, it is coiled at a temperature of 100-150° C. After the coiling is completed, the temperature of the coiled strip is reduced to room temperature at a cooling rate of 3-5° C. / h.

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