Production method of 5005-H34 aluminum alloy plate strip

Abstract

The invention discloses a production method of a 5005-H34 aluminum alloy plate strip, and relates to the technical field of aluminum alloy preparation. The production process comprises the steps of casting, saw cutting, surface milling, heating, hot rolling, intermediate annealing, cold rolling, cleaning, stable annealing and finished product flattening. During production, the following parameters are mainly optimized: controlling the following chemical components in percentage by mass: less than or equal to 0.1% of Si, less than or equal to 0.25% of Fe, less than or equal to 0.15% of Cu, less than or equal to 0.15% of Mn, 0.85-1.05% of Mg, less than or equal to 0.08% of Cr, less than or equal to 0.15% of Zn, 0.01-0.05% of Ti, less than or equal to 0.05% of a single impurity element, less than or equal to 0.15% of other impurity elements and the balance of Al; the finish rolling temperature of hot rough rolling is controlled to be 400-460 DEG C, the total machining rate of hot finish rolling is larger than or equal to 75%, and the finish rolling temperature is 240-260 DEG C; the intermediate annealing metal temperature is controlled to be 320-340 DEG C, and heat preservation is conducted for 3-5 h; and the total machining rate of cold rolling is controlled to be 25-35%. The method is suitable for the 5005-H34 aluminum alloy plate strip with the finished product thickness of 2.0-4.0 mm, the technological process is short, the cost is low, the grain size is small, the small bending radius is achieved, and cracking and orange peel are avoided during bending.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy preparation, and in particular to a production method of a 5005-H34 aluminum alloy plate and strip. Background Art

[0002] 5005 aluminum alloy is more widely used in communication equipment, household appliances, construction industry and other industries due to its advantages such as light weight, better scratch resistance, novelty and uniqueness, strong metallic texture, excellent heat dissipation performance, environmental protection and non-toxicity, no dust absorption and easy cleaning.

[0003] At present, the process flow of 5005-H34 aluminum alloy sheet and strip is: melting and casting → sawing → milling → heating → hot rolling → cold rolling → cleaning → intermediate annealing → finished product cold rolling → cleaning → stabilization annealing → finished product leveling. This process flow is long and the processing cost is high. At the same time, in order to ensure the organizational performance, a large cold rolling processing rate must be reserved, which makes the hot-rolled billet thick and the efficiency is low. 5005-H34 aluminum alloy sheet and strip are also produced according to the H24 process flow, and its process flow is: melting and casting → sawing → milling → heating → hot rolling → cold rolling → cleaning → finished product annealing → stabilization annealing → finished product leveling. This process flow is short, but the annealing temperature range is small, the performance fluctuation is large, and the control cost is high.

[0004] Chinese patent CN107805746B discloses a 5005-H34 aluminum alloy sheet and its production method, which is mainly produced by hot rolling, cold rolling and aluminum coil cleaning, and low temperature 130±10℃ baking to directly produce 5005-H34 sheet products with a thickness of 2.0-4.0mm, which can shorten the production process and ensure the mechanical properties of the product. The 5005 alloy has a low impurity element content and a high recrystallization temperature. In this production method, the hot-rolled coil off the hot rolling line cannot achieve complete recrystallization with residual heat, and the dynamic recovery and recrystallization during the hot rolling process result in a small deformation energy storage at the end of the hot rolling, a large grain size, and fibrous grains after cold rolling to the finished product. There are problems such as easy cracking at small bending radius bending and orange peel on the surface after bending. Therefore, this method is only suitable for the production of products with low bending requirements.

[0005] Based on the above problems, the purpose of this application is to provide a production method of 5005-H34 aluminum alloy plate and strip. Summary of the invention

[0006] In view of the above shortcomings, the present invention provides a production method of 5005-H34 aluminum alloy plate and strip, which solves the problems of long process flow, high cost, easy cracking when bending with a small bending radius and orange peel on the surface after bending. The specific technical scheme is as follows:

[0007] A 5005-H34 aluminum alloy plate and strip, whose chemical composition mass percentage is: Si≤0.1%, Fe≤0.25%, Cu≤0.15%, Mn≤0.15%, Mg: 0.85-1.05%, Cr≤0.08%, Zn≤0.15%, Ti: 0.01-0.05%, other impurity elements individually ≤0.05%, other impurity elements total ≤0.15%, and the rest is Al.

[0008] Furthermore, the grains of the aluminum alloy sheet and strip are substantially completely recrystallized.

[0009] Furthermore, the grains include α-Fe2SiAl8 phase and α-Fe3Si2Al 12 Mutually.

[0010] Furthermore, the average size of the grains is ≤32 μm.

[0011] The present invention also provides a production method of the above 5005-H34 aluminum alloy plate and strip, comprising the following process steps: melting and casting → sawing → milling → heating → hot rolling → intermediate annealing → cold rolling → cleaning → stabilization annealing → finished product leveling;

[0012] The hot rolling: using four-roller reversible hot rough rolling and four-stand hot finishing rolling, the hot rough rolling final rolling temperature is controlled at 400-460°C, the total hot finishing rolling processing rate is ≥75%, the hot finishing rolling final rolling temperature is 240-260°C, and the hot rolled coil thickness is based on the finished product thickness with a 25-35% cold rolling processing rate reserved;

[0013] The intermediate annealing: metal temperature 320 ~ 340 ° C, heat preservation 3 ~ 5h;

[0014] The cold rolling is performed through one cold rolling process to the finished product thickness, and the total processing rate is 25-35%.

[0015] During the hot rolling, the aluminum alloy ingot is rolled into an aluminum alloy hot-rolled strip with a certain thickness and a fibrous grain structure, annealed until completely recrystallized, and then cold rolled with a small processing rate to form a basically completely recrystallized aluminum alloy plate and strip.

[0016] Furthermore, in the heating step, the temperature is 510±10° C. and the insulation time is 2 to 8 hours.

[0017] Furthermore, the hot rolling is to roll the aluminum alloy ingot into an aluminum alloy hot-rolled strip with a thickness of 2.7 to 6.0 mm and a fibrous grain structure.

[0018] Furthermore, the cleaning is to clean the rolling oil and aluminum powder on the surface of the aluminum coil by water washing or alkali washing.

[0019] Furthermore, in the stabilization annealing step, the metal temperature is 120-140° C. and is kept warm for 3-5 hours.

[0020] Furthermore, the finished product is leveled by leveling the aluminum coil using a stretch-bending straightening machine, or leveling the aluminum coil using a cross-cutting machine and then shearing it into a plate; when the finished product is leveled, the plastic deformation rate of the aluminum plate and strip is 0.3-0.5%.

[0021] The mechanical properties and bending of aluminum alloy strips are affected by chemical composition. Mg plays a role in solid solution strengthening as the main element. The Mg content is controlled at an upper limit to ensure that the subsequent cold rolling with a small processing rate can achieve sufficient strength. Si and Fe mainly exist in the form of FeCl3 and free silicon. When the Fe content is greater than Si, α-Fe2SiAl8 (or Fe3Si2Al 12 ), excessive Si and Fe content will increase the tendency of stress cracking, resulting in increased brittleness of the material. Therefore, keeping the Mn, Si, and Fe content at the lowest economically feasible level is beneficial to the bending performance of aluminum alloy sheets and strips.

[0022] The bending effect of 5005 aluminum alloy sheet and strip is also affected by the process parameters of the rolling process. 5005 has a high recrystallization temperature. It is rolled to the O state during hot rolling. The mechanical properties are higher than those of the O state after conventional annealing. The grain size is large, and it is easy to crack or have orange peel patterns when bending. Therefore, a lower final rolling temperature is used in the hot rolling process to roll it to a semi-hard state to form a fibrous grain structure, and then annealed at high temperature to the O state. After the material is completely recrystallized, the grains are small, achieving the effect of grain refinement. After cold rolling with a small processing rate, the grain changes are small, thereby solving the bending orange peel problem and obtaining a good bending effect.

[0023] The invention is suitable for 5005-H34 aluminum alloy plate and strip with a finished product thickness of 2.0 to 4.0 mm.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention solves the problem that the current 5005-H34 aluminum alloy sheet and strip is prone to cracking when bent with a small bending radius and has orange peel on the surface after bending by reasonably matching the main element content, hot rolling final rolling temperature, heat treatment process and cold rolling pass processing rate. Compared with the prior art, the 5005-H34 aluminum alloy sheet and strip produced by the production method of the present invention has a small grain size, does not crack when bent with a small bending radius, and has no orange peel.

[0026] 2. The process of the present invention is short, low in cost and suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0028] Figure 1 This is a comparison chart of the 90°0t bending results of the finished products of Example 1 and Comparative Example 1;

[0029] Figure 2 This is a comparison chart of the 90°0t bending results of the finished products of Example 2 and Comparative Example 2;

[0030] Figure 3 This is a comparison chart of the 90° 0t bending results of the finished products of Example 3 and Comparative Example 3;

[0031] Figure 4 This is a grain comparison diagram of the finished products of Example 1 and Comparative Example 3. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0033] Example 1

[0034] The present embodiment is a production method of 5005-H34 aluminum alloy plate and strip, which includes the following production process: melting and casting → sawing → milling → heating → hot rolling → intermediate annealing → cold rolling → cleaning → stabilization annealing → finished product leveling.

[0035] (1) Melting and casting: The mass percentage of chemical elements in the ingot after melting and casting is:

[0036]

[0037] (2) Heating: Heat the ingot to 515°C and keep it at this temperature for 3 hours.

[0038] (3) Hot rolling: The final rolling temperature of the hot rough rolling is 407°C, the total processing rate of the hot finishing rolling is 81.6%, the final rolling temperature of the hot finishing rolling is 251°C, and the thickness of the hot rolled billet is 4.6 mm.

[0039] (4) Intermediate annealing: The hot-rolled billet is heated to 324°C and kept at this temperature for 4 hours.

[0040] (5) Cold rolling: After one pass of cold rolling, the hot rolled billet is rolled to 3.0 mm, with a total processing rate of 34.8%.

[0041] (6) Cleaning: After cleaning, wipe the surface with a dry paper towel until there is no aluminum ash.

[0042] (7) Stabilization annealing: The strip is heated to 136°C and kept at this temperature for 3 h.

[0043] (8) Finished product leveling: Produced using a tension and bending leveler, with an elongation of 0.35%.

[0044] The grains of the 5005-H34 aluminum alloy strip prepared in this embodiment are basically completely recrystallized, and the average grain size is 31.7 μm (such as Figure 4 As shown), 90°0t bending without cracking (as shown Figure 1 shown).

[0045] Example 2

[0046] The present embodiment is a production method of 5005-H34 aluminum alloy plate and strip, which includes the following production process: melting and casting → sawing → milling → heating → hot rolling → intermediate annealing → cold rolling → cleaning → stabilization annealing → finished product leveling.

[0047] (1) Melting and casting: The mass percentage of chemical elements in the ingot after melting and casting is

[0048]

[0049] (2) Heating: The ingot is heated to 501°C and kept at this temperature for 7 hours.

[0050] (3) Hot rolling: The final rolling temperature of the hot rough rolling is 416°C, the total processing rate of the hot finishing rolling is 88%, the final rolling temperature of the hot finishing rolling is 245°C, and the thickness of the hot rolled billet is 3.0 mm.

[0051] (4) Intermediate annealing: Heat the hot-rolled billet to 331°C and keep it at this temperature for 3 hours.

[0052] (5) Cold rolling: After one cold rolling, the hot rolled billet is rolled to 2.0 mm, with a total processing rate of 33.3%.

[0053] (6) Cleaning: After cleaning, wipe the surface with a dry paper towel until there is no aluminum ash.

[0054] (7) Stabilization annealing: The strip is heated to 129°C and kept at this temperature for 4 hours.

[0055] (8) Finished product leveling: Produced using a tension and bending leveler with an elongation of 0.5%.

[0056] The grains of the 5005-H34 aluminum alloy sheet and strip prepared in this embodiment are basically completely recrystallized, and there is no cracking when bending at 90°0t (such as Figure 2 shown).

[0057] Example 3

[0058] The present embodiment is a production method of 5005-H34 aluminum alloy plate and strip, which includes the following production process: melting and casting → sawing → milling → heating → hot rolling → intermediate annealing → cold rolling → cleaning → stabilization annealing → finished product leveling.

[0059] (1) Melting and casting: The mass percentage of chemical elements in the ingot after melting and casting is

[0060]

[0061] (2) Heating: The ingot is heated to 509°C and kept at this temperature for 5 hours.

[0062] (3) Hot rolling: The final rolling temperature of the hot rough rolling is 455°C, the total processing rate of the hot finishing rolling is 86.4%, the final rolling temperature of the hot finishing rolling is 257°C, and the thickness of the hot rolled billet is 3.6 mm.

[0063] (4) Intermediate annealing: The hot-rolled billet is heated to 331°C and kept at this temperature for 3 h.

[0064] (5) Cold rolling: After one pass of cold rolling, the hot rolled billet is rolled to 2.48 mm, with a total processing rate of 27.1%.

[0065] (6) Cleaning: After cleaning, wipe the surface with a dry paper towel until there is no aluminum ash.

[0066] (7) Stabilization annealing: The strip is heated to 121°C and kept at this temperature for 5 hours.

[0067] (8) Finished product leveling: Produced using a tension and bending leveler, with an elongation of 0.43%.

[0068] The grains of the 5005-H34 aluminum alloy sheet and strip prepared in this embodiment are basically completely recrystallized, and there is no cracking when bending at 90°0t (such as Figure 3 shown).

[0069] Comparative Example 1

[0070] This comparative example is different from Example 1 in that the contents of Si, Fe and Mg in the aluminum alloy are different, and the remaining steps are the same as Example 1.

[0071] The mass percentage of chemical elements in the 5005-H34 aluminum alloy of this comparative example is

[0072]

[0073] The grains of the 5005-H34 aluminum alloy strip prepared in this comparative example are basically fibrous, and the 90°0t bending orange peel texture (such as Figure 1 shown).

[0074] Comparative Example 2

[0075] This comparative example is different from Example 1 in that the final hot rolling temperature is different and there is no intermediate annealing.

[0076] This comparative example includes the following production process: melting and casting → sawing → milling → heating → hot rolling → cold rolling → cleaning → finished product leveling.

[0077] (1) Melting and Casting: The mass percentage of chemical elements in the ingot after melting and casting is the same as that in Example 1.

[0078] (2) Heating: The ingot heating process is the same as that in Example 1.

[0079] (3) Hot rolling: The final hot rolling temperature is 332° C., the hot rolled billet thickness is 4.6 mm, and the other process parameters are the same as those in Example 1.

[0080] (4) Cold rolling: After one pass of cold rolling, the hot rolled billet is rolled to 3.0 mm, with a total processing rate of 34.8%.

[0081] (5) Cleaning: After cleaning, wipe the surface with a dry paper towel until there is no aluminum ash.

[0082] (6) Finished product leveling: Produced using a tension and bending leveler, with an elongation of 0.32%.

[0083] The grains of the 5005-H34 aluminum alloy strip prepared in this comparative example are basically fibrous, and the 90°0t bending cracks (such as Figure 2 shown).

[0084] Comparative Example 3

[0085] This comparative example is different from Example 1 in that the production process is different, which is a short-process 5052-H34 process route.

[0086] This comparative example includes the following production process: melting and casting → sawing → milling → heating → hot rolling → cold rolling → cleaning → stabilization annealing → finished product leveling.

[0087] (1) Melting and Casting: The mass percentage of chemical elements in the ingot after melting and casting is the same as that in Example 1.

[0088] (2) Heating: The ingot heating is the same as in Example 1.

[0089] (3) Hot rolling: The hot rolling final rolling temperature is 320° C., the hot rolled billet thickness is 4.6 mm, and the other process parameters are the same as those in Example 1.

[0090] (4) Cold rolling: After one pass of cold rolling, the hot rolled billet is rolled to 3.0 mm, with a total processing rate of 34.8%.

[0091] (5) Cleaning: After cleaning, wipe the surface with a dry paper towel until there is no aluminum ash.

[0092] (6) Stabilization annealing: The aluminum alloy strip is heated to 135°C and kept at this temperature for 3 hours.

[0093] (7) Finished product leveling: Produced using a tension and bending leveler, with an elongation of 0.34%.

[0094] The grains of the 5005-H34 aluminum alloy strip obtained in this comparative example are basically fibrous structures (such as Figure 4 As shown), 90°0t bending slightly cracked, orange peel texture (as shown Figure 3 shown).

[0095] The mechanical properties and bending properties of the finished products obtained in each embodiment and comparative example were tested, and the results are shown in Table 1:

[0096] Table 1 Mechanical properties and bending properties of the embodiments and comparative examples

[0097] Group Rm(MPa) Rp0.2(MPa) A(％) 90° bend (radius 0t) Example 1 158 141 10 No cracks, no orange peel Example 2 153 137 11 No cracks, no orange peel Example 3 151 136 11 No cracks, no orange peel Comparative Example 1 139 132 10 There is cellulite Comparative Example 2 155 149 5 Cracking Comparative Example 3 156 132 14 Slight cracking, orange peel

[0098] It can be seen from the above table and figure that the mechanical properties of comparative example 1 are relatively soft, lower than the national standard GBT 3880.2. Compared with the comparative example, the grain size of the embodiment is smaller, and there is no cracking or orange peel when bending with a small bending radius, and the embodiment has a better bending effect.

[0099] In summary, the present invention solves the problem that the current 5005-H34 aluminum alloy sheet and strip is prone to cracking when bent with a small bending radius and has orange peel on the surface after bending by reasonably matching the main element content, hot rolling final rolling temperature, heat treatment process and cold rolling pass processing rate. Compared with the prior art, the 5005-H34 aluminum alloy sheet and strip produced by the production method of the present invention has a small grain size, does not crack when bent with a small bending radius, and has no orange peel. At the same time, the present invention has a short process flow, low cost, and is suitable for industrial production.

[0100] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A 5005-H34 aluminum alloy plate and strip, characterized in that: The mass percentages of the chemical composition of the 5005-H34 aluminum alloy are: Si≤0.1%, Fe≤0.25%, Cu≤0.15%, Mn≤0.15%, Mg: 0.85-1.05%, Cr≤0.08%, Zn≤0.15%, Ti: 0.01-0.05%, other impurity elements individually ≤0.05%, other impurity elements total ≤0.15%, and the rest is Al.

2. The 5005-H34 aluminum alloy plate and strip according to claim 1, characterized in that: The grains of the aluminum alloy sheet and strip are completely recrystallized.

3. The 5005-H34 aluminum alloy plate and strip according to claim 2, characterized in that: The grains include α-Fe2SiAl8 phase and α-Fe3Si2Al 12 Mutually.

4. The 5005-H34 aluminum alloy plate and strip according to claim 2, characterized in that: The average size of the grains is ≤32 μm.

5. A method for producing a 5005-H34 aluminum alloy sheet and strip as claimed in any one of claims 1 to 4, characterized in that: The process includes the following steps: melting and casting → sawing → milling → heating → hot rolling → intermediate annealing → cold rolling → cleaning → stabilization annealing → finished product leveling; The hot rolling: using four-roller reversible hot rough rolling and four-stand hot finishing rolling, the hot rough rolling final rolling temperature is controlled at 400-460°C, the total hot finishing rolling processing rate is ≥75%, the hot finishing rolling final rolling temperature is 240-260°C, and the hot rolled coil thickness is based on the finished product thickness with a 25-35% cold rolling processing rate reserved; The intermediate annealing: metal temperature 320 ~ 340 ° C, heat preservation 3 ~ 5h; The cold rolling is performed through one cold rolling process to the finished product thickness, and the total processing rate is 25-35%.

6. The method for producing a 5005-H34 aluminum alloy sheet and strip according to claim 5, characterized in that: In the heating step, the temperature is 510±10° C. and the insulation time is 2 to 8 hours.

7. The method for producing a 5005-H34 aluminum alloy sheet and strip according to claim 5, characterized in that: The hot rolling is to roll the aluminum alloy ingot into an aluminum alloy hot-rolled strip with a thickness of 2.7 to 6.0 mm and a fibrous grain structure.

8. The method for producing a 5005-H34 aluminum alloy sheet and strip according to claim 5, characterized in that: The cleaning is to clean the rolling oil and aluminum powder on the surface of the aluminum coil.

9. The method for producing a 5005-H34 aluminum alloy sheet and strip according to claim 5, characterized in that: In the stabilization annealing step, the metal temperature is 120-140° C. and is kept for 3-5 hours.

10. The method for producing a 5005-H34 aluminum alloy sheet and strip according to claim 5, characterized in that: The finished product leveling is to level the aluminum coil using a stretch bending leveler, or to level the aluminum coil using a cross-cutting machine and then shear it into plates.

Images