Aluminum alloy sheet

Abstract

This aluminum alloy sheet has a composition including no more than 0.5% by mass of Si, no more than 0.7% by mass of Fe, no more than 0.3% by mass of Cu, 0.4% by mass to 1.5% by mass of Mn, and 0.7% by mass to 1.5% by mass of Mg, the remainder comprising Al and unavoidable impurities. The degree of integration in the Goss orientation is at least 1.5. The degree of integration in the Cu orientation is no greater than 6.2. The tensile strength is 200 MPa to 310 MPa. The area ratio of α-Al-Fe-Mn-Si-based intermetallic compounds having an equivalent circle diameter of at least 0.5 µm is preferably at least 2.6%.

Description

Aluminum alloy plate Cross-reference to related applications

[0001] This international application claims priority based on Japanese Patent Application No. 2018-163486 filed with the Japan Patent Office on August 31, 2018, and incorporates the entire contents of Japanese Patent Application No. 2018-163486 by reference into this international application.

[0002] This disclosure relates to an aluminum alloy plate.

[0003] In recent years, bottle cans, which are a type of aluminum can, have been commercially available. A bottle can has a body portion and a neck portion. The neck portion is thinner than the body portion. The bottle can has a threaded portion near the tip of the neck portion. The bottle can can be sealed using the threaded portion and a cap.

[0004] A bottle can is manufactured as follows. First, a circular blank is subjected to drawing to form a cup. Next, the cup is redrawn using a body maker. Further, ironing is continuously performed following the redrawing to form a can body.

[0005] Next, the opening of the can body is trimmed to align the height of the can body. Next, neck processing is performed to form the neck portion. Next, a threaded portion is formed near the tip of the neck portion. Finally, curling is performed at the tip of the neck portion.

[0006] When manufacturing a bottle can, the diameter reduction rate in neck processing is large. When the diameter reduction rate in neck processing is large, a large compressive stress is applied to the can wall, and the wall thickness increases. When the wall thickness increases, irregularities are formed on the surface of the can wall, and eventually, minute cracks occur. During curling, the minute cracks serve as the starting point of fracture, resulting in curl cracking.

[0007] In Patent Documents 1 and 2, technologies for improving curl cracking have been developed. In the technology described in Patent Document 1, the crystal grain size is finely controlled. Also, in the technology described in Patent Document 1, the in-plane anisotropy of the Lankford value is defined. In the technology described in Patent Document 2, in order to achieve both the workability and strength of the bottle can, the conditions of the final pass of finish rolling and the final pass of cold rolling are adjusted to define the ear rate and the strength before and after baking.

[0008] Japanese Patent Publication No. 4460406, Japanese Unexamined Patent Publication No. 2009-242831

[0009] The technologies described in Patent Documents 1 and 2 have made it difficult to sufficiently suppress curl cracking. Furthermore, aluminum alloy sheets are required to have high tensile strength. In one aspect of this disclosure, it is preferable to provide an aluminum alloy sheet that can suppress curl cracking and has high tensile strength.

[0010] One aspect of this disclosure is an aluminum alloy sheet having a composition comprising 0.5 mass% or less of Si, 0.7 mass% or less of Fe, 0.3 mass% or less of Cu, 0.4 mass% to 1.5 mass% of Mn, and 0.7 mass% to 1.5 mass% of Mg, with the remainder being Al and unavoidable impurities, having a Goss orientation concentration of 1.5 or more, a Cu orientation concentration of 6.2 or less, and a tensile strength of 200 MPa to 310 MPa. This aluminum alloy sheet, one aspect of this disclosure, can suppress curl cracking and has high tensile strength.

[0011] Figure 1A is an explanatory diagram showing an example of deformed texture A, and Figure 1B is an explanatory diagram showing an example of deformed texture B.

[0012] Exemplary embodiments of this disclosure will be described with reference to the drawings.

[0013] 1. Composition of the Aluminum Alloy Sheet The aluminum alloy sheet of this disclosure contains 0.4% by mass or more and 1.5% by mass or less of Mn. Mn contributes to improving the strength of the aluminum alloy sheet by solid solution or precipitation in the aluminum alloy sheet of this disclosure. Therefore, Mn improves the tensile strength of the aluminum alloy sheet of this disclosure. The aluminum alloy sheet of this disclosure has high tensile strength due to the Mn content of 0.4% by mass or more. The Mn content is preferably 0.7% by mass or more. When the Mn content is 0.7% by mass or more, the formability of the aluminum alloy sheet of this disclosure is further improved.

[0014] Conventionally, giant compounds have sometimes formed in aluminum alloy sheets. Giant compounds are large crystals larger than 100 μm. Giant compounds act as fracture initiation points during molding or when subjected to external impact. Because the Mn content is 1.5 mass% or less, the aluminum alloy sheet of this disclosure is less prone to the formation of giant compounds.

[0015] Mn forms an Al-Fe-Mn-Si intermetallic compound. This Al-Fe-Mn-Si intermetallic compound is the α-phase. The Al-Fe-Mn-Si intermetallic compound promotes uniform deformation during neck forming. The higher the Mn content, the greater the amount of the Al-Fe-Mn-Si intermetallic compound.

[0016] The aluminum alloy sheet of this disclosure contains 0.5% by mass or less of Si. The aluminum alloy sheet of this disclosure does not need to contain Si, but it is preferable that the Si content is 0.1% by mass or more. When the Si content is 0.1% by mass or more, the formability of the aluminum alloy sheet of this disclosure is further improved.

[0017] The Si content is 0.5% by mass or less, which makes it less likely for precipitates to form during hot rolling and promotes recrystallization during hot finishing rolling. As a result, the concentration of Goss orientation tends to be 1.5 or higher, and the concentration of Cu orientation tends to be 6.2 or lower.

[0018] Si, together with Mn, forms Al-Fe-Mn-Si intermetallic compounds. These Al-Fe-Mn-Si compounds promote uniform deformation during neck forming. The higher the Si content, the greater the amount of Al-Fe-Mn-Si intermetallic compounds.

[0019] The aluminum alloy sheet of this disclosure contains 0.7% by mass or less of Fe. Preferably, the Fe content is 0.45% by mass or more. When the Fe content is 0.45% by mass or more, the formability of the aluminum alloy sheet of this disclosure is even better. Because the Fe content is 0.7% by mass or less, the aluminum alloy sheet of this disclosure is less prone to giant compounding.

[0020] Fe, along with Si and Mn, forms Al-Fe-Mn-Si intermetallic compounds. These Al-Fe-Mn-Si compounds promote uniform deformation during neck forming. The higher the Fe content, the greater the amount of Al-Fe-Mn-Si intermetallic compounds.

[0021] The aluminum alloy sheet of this disclosure contains 0.3% by mass or less of Cu. Cu improves the tensile strength of the aluminum alloy sheet of this disclosure by forming Al-Mg-Cu precipitates during cold rolling and the paint-baking process after sheet fabrication. Preferably, the Cu content is 0.05% by mass or more. When the Cu content is 0.05% by mass or more, the tensile strength of the aluminum alloy sheet of this disclosure is further improved. Because the Cu content is 0.3% by mass or less, the tensile strength of the aluminum alloy sheet of this disclosure is less likely to become excessively high. As a result, the aluminum alloy sheet of this disclosure is less prone to defects during molding.

[0022] The aluminum alloy sheet of this disclosure contains 0.7% by mass or more and 1.5% by mass or less of Mg. Mg improves the strength of the aluminum alloy sheet of this disclosure. By having an Mg content of 0.7% by mass or more, the aluminum alloy sheet of this disclosure can ensure sufficient strength for a can body.

[0023] Because the Mg content is 1.5% by mass or less, the tensile strength of the aluminum alloy sheet of this disclosure is not likely to become excessively high. As a result, the aluminum alloy sheet of this disclosure can suppress forming cracks.

[0024] The aluminum alloy sheet of this disclosure may contain 0.1% by mass or less of Ti as an unavoidable impurity. Ti contributes to the refinement of the ingot structure.

[0025] In the aluminum alloy sheet of this disclosure, the remainder consists of Al and unavoidable impurities. Examples of unavoidable impurities include, in addition to the Ti mentioned above, Cr at a concentration of 0.3 mass% or less, and Zn at a concentration of 0.5 mass% or less. Preferably, the type and amount of unavoidable impurities are within a range that does not significantly impair the performance of the aluminum alloy sheet of this disclosure.

[0026] 2. Degree of Accumulation of Goss Orientation and Degree of Accumulation of Cu Orientation In the aluminum alloy sheet of this disclosure, the degree of accumulation of Goss orientation is 1.5 or higher. The degree of accumulation of Goss orientation refers to the degree of accumulation of Goss orientation {110} <100>. In addition, in the aluminum alloy sheet of this disclosure, the degree of accumulation of Cu orientation is 6.2 or lower. The degree of accumulation of Cu orientation refers to the degree of accumulation of Cu orientation {112} <111>.

[0027] The aluminum alloy sheet disclosed herein can suppress curl cracking because the concentration of Goss orientation is 1.5 or higher and the concentration of Cu orientation is 6.2 or lower. The relationship between the concentration of Goss orientation and Cu orientation and the likelihood of curl cracking is presumed to be as follows.

[0028] When manufacturing bottle cans and the like using aluminum alloy sheets, the base sheet is subjected to DI forming, followed by neck forming. The base sheet refers to the aluminum alloy sheet before DI forming. DI forming deforms the texture of the base sheet, creating a deformation texture (hereinafter referred to as the deformation texture of the DI-formed can wall). The deformation behavior of the can wall during neck forming is governed by the deformation texture of the DI-formed can wall.

[0029] Through the inventor's investigation, it became clear that the deformation texture of the DI can wall consists of two types: deformation texture A, where the {111} plane is perpendicular to the DI direction, and deformation texture B, where the {100} plane is perpendicular to the DI direction.

[0030] An example of deformation texture A is shown in Figure 1A. An example of deformation texture B is shown in Figure 1B. Figures 1A and 1B are cross-sections near the opening of the DI can wall, observed using SEM-EBSD in a cross-section perpendicular to the DI direction, and the distribution of crystal grains within the same field of view is displayed separated by crystal grain orientation.

[0031] In the following, the crystal orientation distribution function of the deformation texture of the can wall is expressed following the same convention as the crystal orientation distribution function of the texture of the rolled sheet. That is, the plane parallel to the can wall surface is considered equivalent to the rolling plane. Also, the DI direction (height direction) of the can is considered equivalent to the rolling direction. Furthermore, the angles of the crystal orientation distribution function are expressed using Euler angles obtained by the Bunge method. Deformation texture A corresponds to a texture with angles close to the Cu orientation (φ1 = 90°, Φ = 30°, φ2 = 45°). Deformation texture B corresponds to a texture with angles close to the Goss orientation (φ1 = 0°, Φ = 45°, φ2 = 0°).

[0032] Deformed texture A deforms in the thickness direction of the can wall during neck forming, inducing surface irregularities and forming microcracks. The degree of accumulation of deformed texture A correlates with the degree of accumulation of Cu orientation in the original plate. The greater the degree of accumulation of Cu orientation in the original plate, the greater the degree of accumulation of deformed texture A in the DI can wall.

[0033] The deformation texture B deforms not only in the wall thickness direction but also in the height direction during neck forming. In other words, the direction of deformation of the deformation texture B during neck forming is dispersed. Therefore, the deformation texture B has little contribution to the formation of microcracks on the can wall surface. The degree of accumulation of the deformation texture B is correlated with the degree of accumulation of the Goss orientation in the original plate. The greater the degree of accumulation of the Goss orientation in the original plate, the greater the degree of accumulation of the deformation texture B in the DI can wall.

[0034] Therefore, by reducing the concentration of Cu orientations and increasing the concentration of Goss orientations in the original plate, a structure can be formed in the can wall after DI molding that suppresses the formation of microcracks.

[0035] When the concentration of Goss orientation is 1.5 or higher, the deformation direction of the crystal grains during neck forming is less likely to be localized in the same direction, making it less likely for microcracks to occur on the surface of the can wall. As a result, curl cracking is less likely to occur. When the concentration of Cu orientation is 6.2 or lower, the deformation in the wall thickness direction during neck forming is reduced, making it less likely for microcracks to occur on the surface of the can wall. As a result, curl cracking is less likely to occur.

[0036] The degree of accumulation of Cu orientation and Goss orientation can be measured as follows. A square measurement sample is prepared with a length of 2 cm in the rolling direction and a length of 2 cm in the perpendicular direction. An incomplete pole figure is obtained by performing Schultz reflection (α = 15° to 90°, β = 0° to 360°) on the surface of the measurement sample using an X-ray diffractometer. From the incomplete pole figure, the crystal orientation distribution function f(φ1, Φ, φ2) is determined by a 22nd-order series expansion method. The analysis software "Standard ODF" commercially available from Norm Engineering Co., Ltd. is used to determine the crystal orientation distribution function. The principle of determining the crystal orientation distribution function from the incomplete pole figure is publicly known and is disclosed, for example, in the following publicly known documents.

[0037] Publicly available literature: Hiroshi Inoue, Naotsugu Inakazu: Journal of the Japan Institute of Metals, 58 (1994), 892-898. The degree of accumulation of Cu orientation and Goss orientation is calculated by analyzing the crystal orientation distribution function.

[0038] 3. Tensile Strength The tensile strength of the aluminum alloy sheet of this disclosure is 200 MPa or more and 310 MPa or less. A tensile strength of 200 MPa or more results in high can body strength after molding. A tensile strength of 310 MPa or less makes it less likely for the can body to break. Can body breakage is a phenomenon in which the can body breaks during can manufacturing.

[0039] The method for measuring tensile strength is the method specified in JIS-Z-2241. The greater the cold rolling ratio when manufacturing the aluminum alloy sheet of this disclosure, the greater the tensile strength. The greater the Mn content in the aluminum alloy sheet of this disclosure, the greater the tensile strength. The greater the Cu content in the aluminum alloy sheet of this disclosure, the greater the tensile strength. The greater the Mg content in the aluminum alloy sheet of this disclosure, the greater the tensile strength.

[0040] 4. Area ratio of α-Al-Fe-Mn-Si intermetallic compounds with an equivalent circular diameter of 0.5 μm or more In the aluminum alloy sheet of this disclosure, the area ratio of α-Al-Fe-Mn-Si intermetallic compounds with an equivalent circular diameter of 0.5 μm or more (hereinafter referred to as the area ratio of the α phase) is preferably 2.6% or more.

[0041] When the area ratio of the α-phase is 2.6% or more, the aluminum alloy sheet of the present disclosure deforms more evenly during neck forming. Also, when the area ratio of the α-phase is 2.6% or more, the lubricity between the aluminum alloy sheet of the present disclosure and the mold is improved. As a result, the formability of the aluminum alloy sheet of the present disclosure is improved.

[0042] When the area ratio of the α-phase is 2.6% or more, the reason for the above effects is presumably as follows. The α-Al-Fe-Mn-Si-based intermetallic compound with an equivalent circle diameter of 0.5 μm or more hinders the movement of crystal grains during plastic deformation such as cold rolling, DI forming, and neck forming, and suppresses the accumulation of Cu orientation and the deformation of the aggregate structure in a specific direction. Therefore, when the area ratio of the α-phase is 2.6% or more, the aluminum alloy sheet of the present disclosure deforms more evenly during neck forming.

[0043] The α-Al-Fe-Mn-Si-based intermetallic compound with an equivalent circle diameter of 0.5 μm or more improves the lubricity between the aluminum alloy sheet of the present disclosure and the mold. As a result, when the area ratio of the α-phase is 2.6% or more, the formability of the aluminum alloy sheet of the present disclosure is improved.

[0044] The area ratio of the α-phase can be measured by the following method. Polish the surface of the measurement sample where the measurement is to be performed. The depth of polishing shall be 1% of the plate thickness of the measurement sample. Observe the polished surface using SEM-COMPO to obtain 10 fields of view. The magnification of SEM-COMPO shall be 500 times. In 10 fields of view, use the image analysis software "A-Image-kun" to obtain the area of white contrast particles with an equivalent circle diameter of 0.5 μm or more (hereinafter referred to as the white contrast area). The area ratio of the α-phase is calculated by dividing the white contrast area by the total area of 10 fields of view. Note that the α-Al-Fe-Mn-Si-based intermetallic compound contains Fe and Mn, which are heavier elements than the matrix phase Al, and is thus observed as white contrast particles in the SEM-COMPO image.

[0045] 5. Method for manufacturing aluminum alloy sheet of the present disclosureThe aluminum alloy sheet of the present disclosure can be manufactured, for example, as follows. For an aluminum alloy having a composition corresponding to the aluminum alloy sheet of the present disclosure, a semi-continuous casting method (DC casting) is performed according to a conventional method to produce an ingot.

[0046] Next, the surface of the ingot is face-milled. Next, the ingot is put into a soaking furnace for homogenization treatment. It is preferable to perform the homogenization treatment at a high temperature. It is preferable to perform the homogenization treatment for a long time. By the homogenization treatment, the intermetallic compound of Al6Mn is transformed into the α phase.

[0047] The temperature in the homogenization treatment is preferably 520°C or higher and 620°C or lower. The time of the homogenization treatment is preferably 1 hour or longer and 5 hours or shorter. When the temperature in the homogenization treatment is 520°C or higher, the transformation of the precipitate into the α phase proceeds sufficiently. When the temperature in the homogenization treatment is 620°C or lower, local melting of the aluminum alloy hardly occurs.

[0048] When the time of the homogenization treatment is 1 hour or longer, the transformation of the precipitate into the α phase proceeds sufficiently. When the time of the homogenization treatment exceeds 5 hours, the effect of the homogenization treatment saturates.

[0049] Next, the ingot subjected to the homogenization treatment is subjected to hot rolling. The hot rolling includes rough rolling and finish rolling. The rough rolling is a process of processing the ingot into a plate material with a thickness of about several tens of mm by reverse rolling. The finish rolling is a process of reducing the thickness of the plate material to about several mm by tandem rolling or the like and winding it into a coil shape. The member wound into a coil shape is hereinafter referred to as a hot-rolled coil. Next, cold rolling is performed on the hot-rolled coil. In cold rolling, it is rolled thinly until the plate thickness becomes the product plate thickness.

[0050] [[ID=第十五]] For each of the final pass of the rough rolling and the final pass of the finish rolling, the Z value represented by the following formula (1) can be calculated. When the finish rolling is tandem rolling, the final pass of the finish rolling is the rolling at the final stand. [[ID=十六]] [[ID=十七]]

[0051] [[ID=十八]] In equation (1), ε is the strain rate. Q is the activation energy for hot working. The value of Q is 156 kJ / mol. R is the gas constant. The value of R is 8.314 JK. -1 mol -1 Here, T is the processing temperature. The strain rate ε is calculated using the following equation (2).

[0052] In equation (2), n is the rotational speed (rpm) of the rolling rolls, and r is the reduction ratio. A H0 is the roll radius. H0 is the thickness of the sheet metal on the rolling entry side.

[0053] The Z-value is an indicator of the amount of strain accumulated during hot working. The larger the Z-value, the easier recrystallization occurs. In hot-rolled coils, the residual heat after winding causes the material structure to recrystallize. As a result, the concentration of Goss orientations increases. The more the rolled structure develops without recrystallization during rough rolling, the greater the concentration of Goss orientations becomes due to recrystallization after finish rolling.

[0054] In other words, the lower the Z value of the final pass in rough rolling and the higher the Z value of the finish rolling, the greater the concentration of Goss orientations and the smaller the concentration of Cu orientations. For example, the Z value of the final pass in rough rolling can be adjusted to satisfy the equation logZ < 11.7. In this case, recrystallization in the final pass of rough rolling can be suppressed. It is even more preferable that the Z value of the final pass in rough rolling satisfies the equation logZ < 11.3.

[0055] Furthermore, it is preferable to adjust the Z value of the finish rolling process to satisfy the equation logZ > 14.4, and to set the processing temperature of the finish rolling process to 330°C or higher. In this case, the material microstructure recrystallizes sufficiently. As a result, the concentration of Goss orientations increases, and the concentration of Cu orientations decreases.

[0056] Cold rolling may be either single rolling or tandem rolling. The smaller the cold rolling ratio, the greater the concentration of Goss orientations and the smaller the concentration of Cu orientations. Therefore, the smaller the cold rolling ratio, the less likely curl cracking is to occur.

[0057] The greater the cold rolling ratio, the higher the tensile strength of the aluminum alloy sheet according to this disclosure. When the cold rolling ratio is high, it is preferable to increase the concentration of Goss orientations and decrease the concentration of Cu orientations during the hot rolling stage.

[0058] The cold rolling ratio is preferably 70% or more and 85% or less. When the cold rolling ratio is 70% or more, the tensile strength of the aluminum alloy sheet of this disclosure is high. Also, when the cold rolling ratio is 70% or more, the rigidity of the can body after forming is high. When the cold rolling ratio is 85% or less, the concentration of Cu orientation is less likely to become excessively large. As a result, curl cracking can be suppressed. The cold rolling ratio is even more preferably 83% or less.

[0059] Insofar as the effects of the aluminum alloy sheet of this disclosure are achieved, the method for manufacturing the aluminum alloy sheet of this disclosure may include, for example, annealing before and after cold rolling or between passes.

[0060] 6. Examples (6-1) Manufacturing of Aluminum Alloy Sheets Aluminum alloy sheets S1 to S8 as described in Table 1 were manufactured. The manufacturing method is as follows.

[0061] First, an ingot was produced by a semi-continuous casting method. The composition of the ingot is shown in Table 1. The thickness of the ingot is 700 mm. The ingot contains 0.03 mass% of unavoidable impurity elements. Next, the four sides of the ingot were machined. Then, the ingot was placed in a furnace and homogenized under the conditions shown in Table 1.

[0062] Next, the ingot was discharged from the furnace, and hot rolling was immediately started. The hot rolling mill used at this time consisted of a reverse-type hot roughing mill and a tandem-type hot finishing mill. The Z value of the final pass of the reverse-type hot roughing mill was controlled to the value shown in Table 1. In addition, the Z value at the final stand of the tandem-type hot finishing mill was controlled to the value shown in Table 1.

[0063] Next, cold rolling was performed. The cold rolling ratio in cold rolling was adjusted to the values ​​shown in Table 1 by adjusting the sheet thickness after hot finishing rolling. (6-2) Evaluation of aluminum alloy sheets A No. 5 test specimen, as specified in JIS-Z-2241, was prepared from the manufactured aluminum alloy sheets. This test specimen stretches in a direction that forms a 0° angle with respect to the rolling direction. A tensile test was performed on this test specimen in accordance with JIS-Z-2241, and the tensile strength was measured. The results of the tensile strength measurement are shown in Table 1.

[0064] The concentration of Goss orientation and Cu orientation was measured in the manufactured aluminum alloy plate using the measurement method described above. A Rigaku RINT-2500V / PC X-ray diffractometer was used. The measurement results for the concentration of Goss orientation and Cu orientation are shown in Table 1.

[0065] The area fraction of the α phase was measured in the manufactured aluminum alloy sheet using the measurement method described above. The measurement results for the area fraction of the α phase are shown in Table 1.

[0066] A can body was formed by DI molding from a manufactured aluminum alloy sheet to a diameter of 66 mm. Next, the flange portion of the can body was neck-formed to a diameter of 32 mm, and the tip of the neck portion was curl-formed. Samples with a curl cracking rate of 10% or less were judged to have good curl formability. Samples with a curl cracking rate exceeding 10% were judged to have poor curl formability. In Table 1, good results are indicated by "○" and poor results by "×".

[0067] In samples S2, S6, S7, and S8, the concentration of Cu orientations was 6.2 or less, resulting in good curl-formability evaluation results and high tensile strength. In contrast, in samples S1, S3, S4, and S5, the concentration of Cu orientations exceeded 6.2, resulting in poor curl-formability evaluation results.

[0068] S6 showed better curl-forming properties compared to S5 and S6. This is because S6 contains 0.45% or more by mass of Fe, resulting in a higher area ratio of the α phase and a lower concentration of Cu orientation.

[0069] In S7 and S8, the cold rolling reduction ratio is low, and the concentration of Cu orientations is low. This indicates that reducing the cold rolling reduction ratio can suppress the concentration of Cu orientations.

[0070] In S4, compared to S1, the logZ of the rough rolling is lower, and the concentration of Goss orientations is greater. This indicates that the concentration of Goss orientations can be increased by lowering the logZ of the rough rolling.

[0071] 7. Other Embodiments Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0072] (1) The function of one component in each of the above embodiments may be divided among multiple components, or the function of multiple components may be performed by one component. Also, a part of the configuration of each of the above embodiments may be omitted. Also, at least a part of the configuration of each of the above embodiments may be added to, substituted for, etc., the configuration of other above embodiments. Any aspect of the technical concept specified by the wording of the claims is an embodiment of the present disclosure.

[0073] (2) In addition to the aluminum alloy plate described above, this disclosure can also be realized in various forms, such as a system using the aluminum alloy plate as a component, a method for manufacturing the aluminum alloy plate, etc.

Claims

1. Aluminum alloy sheets containing the following composition: 0.5% or less by mass of Si; 0.7% or less by mass of Fe; 0.3% or less by mass of Cu; 0.4 to 1.5% by mass of Mn; 0.7 to 1.5% by mass of Mg; and the remaining composition consisting of Al and unavoidable impurities, where the degree of inclusion in the Gauss direction is 1.5 or more, where the degree of inclusion in the Cu direction is 6.2 or less, and where the tensile strength is 200 to 310 MPa.

2. Aluminum alloy sheets according to claim 1, where the Si content is 0.1 to 0.5% by mass, where the Fe content is 0.45 to 0.7% by mass, where the Cu content is 0.05 to 0.3% by mass, where the Mn content is 0.7 to 1.5% by mass, and... Where the spatial ratio of basic metallic compounds (alpha)-Al-Fe-Mn-Si with an equivalent circle diameter of 0.5 micrometers or more is 2.6% or more;