JP7111563B2 - aluminum alloy plate - Google Patents

Description

The present disclosure relates to aluminum alloy plates.

In recent years, bottle cans, which are one kind of aluminum cans, have been commercially available. A bottle can has a body and a neck. The neck is narrower than the body. Bottle cans have a threaded portion near the tip of the neck portion. Bottle cans can be resealed using their threads and caps.

Bottle cans are manufactured as follows. First, a circular blank is drawn to form a cup. The cup is then redrawed using a body maker. Further, ironing is performed continuously with redrawing to form a can body.

Next, the opening of the can body is trimmed to make the height of the can body uniform. Next, neck processing is performed to form a neck portion. Next, a threaded portion is formed near the tip of the neck portion. Finally, the tip of the neck portion is curled.

When manufacturing bottle cans, the diameter reduction ratio in neck processing is large. If the diameter reduction rate in necking is large, a large compressive stress is applied to the can wall, increasing the wall thickness. As the wall thickness increases, irregularities are formed on the surface of the can wall, eventually resulting in microcracks. During curling, a minute crack becomes the starting point of fracture, resulting in curl cracking.

Patent Documents 1 and 2 disclose techniques aimed at improving curl cracks. The technique described in Patent Document 1 finely controls the crystal grain size. Further, in the technique described in Patent Document 1, the in-plane anisotropy of the Lankford value is specified. In the technique described in Patent Document 2, in order to achieve both workability and strength of bottle cans, the conditions of the final pass of finish rolling and the final pass of cold rolling are adjusted to define the ear ratio and the strength before and after baking. is doing.

Japanese Patent No. 4460406 JP 2009-242831 A

With the techniques described in Patent Documents 1 and 2, it was difficult to sufficiently suppress curl cracks. In addition, the aluminum alloy plate is required to have high tensile strength. An object of one aspect of the present disclosure is to provide an aluminum alloy plate that can suppress curl cracking and has high tensile strength.

One aspect of the present disclosure is a A composition containing Mn and 0.7% by mass or more and 1.5% by mass or less of Mg, with the balance being Al and unavoidable impurities, and the crystal orientation distribution function φ1 = 65 ° to 90 °, Φ = The integrated value in the interval of 30° and φ2 = 45° is 120 or less, and the integrated value in the interval of φ1 = 0 to 35°, Φ = 45° and φ2 = 0° of the crystal orientation distribution function is 80 or more, The aluminum alloy plate has a tensile strength of 280 MPa or more and 330 MPa or less. An aluminum alloy plate that is one aspect of the present disclosure can suppress curl cracking and has high tensile strength.

1A is an explanatory diagram showing an example of a modified texture A, and FIG. 1B is an explanatory diagram showing an example of a modified texture B. FIG.

Exemplary embodiments of the present disclosure are described with reference to the drawings.
1. Composition of Aluminum Alloy Plate The aluminum alloy plate of the present disclosure contains 0.4% by mass or more and 1.5% by mass or less of Mn. Mn forms a solid solution in the aluminum alloy sheet of the present disclosure. Therefore, Mn improves the tensile strength of the aluminum alloy plate of the present disclosure. Due to the Mn content of 0.4% by mass or more, the aluminum alloy plate of the present disclosure has high tensile strength. The content of Mn 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 the present disclosure is even better.

Conventionally, a giant compound was generated in an aluminum alloy plate. A giant compound is a giant crystallized substance of 100 μm or more. The giant compound becomes the starting point of fracture during molding or when receiving an impact from the outside. Since the Mn content is 1.5% by mass or less, the aluminum alloy plate of the present disclosure is less likely to form giant compounds.

Mn forms an Al--Fe--Mn--Si intermetallic compound. The Al--Fe--Mn--Si system intermetallic compound is the α phase. The Al--Fe--Mn--Si based intermetallic compound promotes uniform deformation during neck molding. Al--Fe--Mn--Si based intermetallic compounds increase as the Mn content increases.

The aluminum alloy plate of the present disclosure contains 0.50% by mass or less of Si. The aluminum alloy plate of the present disclosure may not contain Si, but the Si content is preferably 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 the present disclosure is even better.

When the Si content is 0.50% by mass or less, precipitates are less likely to occur during hot rolling, and recrystallization during hot finish rolling can be promoted. As a result, the degree of accumulation in the section of the Goss orientation from the Cube orientation (φ1=0°, Φ=0°, φ2=0°) of the crystal orientation distribution function increases. The Si content is preferably 0.45% by mass or less. When the Si content is 0.45% by mass or less, the above effect becomes even more pronounced. The lower the Si content, the more pronounced the above effect.

Si forms an Al--Fe--Mn--Si intermetallic compound together with Mn. The Al--Fe--Mn--Si based intermetallic compound promotes uniform deformation during neck molding. Al--Fe--Mn--Si based intermetallic compounds increase as the Si content increases.

The aluminum alloy plate of the present disclosure contains 0.7% by mass or less of Fe. The Fe content is preferably 0.3% by mass or more. When the Fe content is 0.3% by mass or more, the formability of the aluminum alloy sheet of the present disclosure is even better. Since the Fe content is 0.7% by mass or less, the aluminum alloy plate of the present disclosure is less likely to form giant compounds.

Fe forms an Al--Fe--Mn--Si intermetallic compound together with Si and Mn. The Al--Fe--Mn--Si based intermetallic compound promotes uniform deformation during neck molding. As the Fe content increases, the Al--Fe--Mn--Si intermetallic compound increases.

The aluminum alloy plate of the present disclosure contains 0.3% by mass or less of Cu. Cu improves the tensile strength of the aluminum alloy sheet of the present disclosure by forming Al--Mg--Cu-based precipitates during cold rolling and during the paint baking process after can manufacturing. The Cu content is preferably 0.05% by mass or more. When the Cu content is 0.05% by mass or more, the tensile strength of the aluminum alloy plate of the present disclosure is further improved. Since the Cu content is 0.3% by mass or less, the tensile strength of the aluminum alloy plate of the present disclosure is unlikely to be excessively high. As a result, the aluminum alloy plate of the present disclosure is less likely to cause defects during forming.

The aluminum alloy plate of the present disclosure contains 0.7% by mass or more and 1.5% by mass or less of Mg. Mg improves work hardenability and ductility of the aluminum alloy plate of the present disclosure. The greater the ductility of the material, the less likely curl cracks will occur. When the Mg content is 0.7% by mass or more, the aluminum alloy sheet of the present disclosure has high ductility and can suppress curl cracks.

Since the Mg content is 1.5% by mass or less, the tensile strength of the aluminum alloy sheet of the present disclosure is unlikely to be excessively high. As a result, the aluminum alloy plate of the present disclosure can suppress forming cracks.
The aluminum alloy plate of the present disclosure contains, for example, 0.1% by mass or less of Ti. The aluminum alloy plate of the present disclosure may not contain Ti. Ti contributes to refinement of the ingot structure.

In the aluminum alloy plate of the present disclosure, the balance consists of Al and unavoidable impurities. The aluminum alloy plate of the present disclosure may or may not contain unavoidable impurities. Examples of unavoidable impurities include Cr of 0.3% by mass or less and Zn of 0.5% by mass or less. The types and amounts of unavoidable impurities are preferably within a range that does not significantly impair the performance of the aluminum alloy sheet of the present disclosure.

2. Integral value of crystal orientation distribution function In the aluminum alloy plate of the present disclosure, the integral value of the crystal orientation distribution function in the interval of φ1 = 65 ° to 90 °, Φ = 30 °, φ2 = 45 ° (hereinafter, the integrated value in the interval K ) is 120 or less. In addition, in the aluminum alloy plate of the present disclosure, the integral value of the section of the crystal orientation distribution function φ1 = 0 to 35°, φ = 45°, φ2 = 0° (hereinafter referred to as the integral value of the section M) is 80 or more. is.

In the aluminum alloy plate of the present disclosure, the integrated value of the crystal orientation distribution function in the interval of φ ₁ = 0°, Φ = 0° to 45°, and φ ₂ = 0° (hereinafter referred to as the integrated value in the interval L) is 80. It is preferable that it is above.
The aluminum alloy plate of the present disclosure has an integral value of 120 or less in section K and an integral value of 80 or more in section M, so that curl cracks can be suppressed. The aluminum alloy plate of the present disclosure can further suppress curl cracking when the integral value of section L is 80 or more.

The relationship between the integral values of the sections K, L, and M and the difficulty of curl cracking is presumed as follows. When a bottle can or the like is manufactured using an aluminum alloy sheet, the base sheet is subjected to DI forming and then neck forming. A base plate means an aluminum alloy plate before DI forming. By DI forming, the texture of the base plate is deformed, and a deformed texture (hereinafter referred to as a deformed texture of the DI can wall) is generated in the can wall. The deformation behavior of the can wall during neck forming is governed by the deformation texture of the DI can wall.

According to the inventor's study, the deformation texture of the DI can wall includes a deformation texture A in which the {111} plane is perpendicular to the DI direction and a deformation texture B in which the {100} plane is perpendicular to the DI direction. became clear.
An example of modified texture A is shown in FIG. 1A. An example of modified texture B is shown in FIG. 1B. 1A and 1B are cross-sections near the opening of the DI can wall, the cross-section perpendicular to the DI direction observed by the SEM-EBSD method, and the distribution of crystal grains occupying the same field of view. Each is separated and displayed.

The crystal orientation distribution function of the deformed texture of the DI can wall is represented by following the crystal orientation distribution function of the texture of the rolled sheet. That is, the surface parallel to the can wall surface is considered equivalent to the rolled surface. Also, the ironing direction of the can is considered equivalent to the rolling direction. Also, the angles of the crystal orientation distribution function are represented by Euler angles according to the Bunge method. Deformed texture A corresponds to the texture at angles close to the Cu orientation (φ1=90°, φ=30°, φ2=45°). Deformed texture B corresponds to the texture at angles close to the Goss orientation (φ1=0°, φ=45°, φ2=0°).

The deformed texture A is deformed in the thickness direction of the can wall during neck molding to induce irregularities on the surface and form microcracks. The integrated value of the section K in the base plate has a correlation with the degree of accumulation of the deformed texture A. The greater the integrated value of the section K in the base plate, the greater the degree of accumulation of the deformation texture A of the DI can wall.

The reason for this is that the crystal grains of the orientation included in the interval K of the crystal orientation distribution function of the base plate cause crystal lattice rotation around the axis perpendicular to the can wall surface during deep drawing, and ironing. This is because the crystal lattice rotates about the circumferential direction of the can at times, and finally rotates toward the deformed texture A on the can side wall. Crystal lattice rotation about the direction perpendicular to the can wall surface is crystal lattice rotation in the Euler angle φ1 direction. Crystal lattice rotation about the can circumferential direction is crystal lattice rotation in the Euler angle Φ direction. Note that the section K also includes the Cu orientation. Further, since such crystal lattice rotation occurs due to deep drawing and ironing, the degree of accumulation of the deformed texture A has a positive correlation with the drawing ratio and ironing rate in DI forming.

Deformation texture B deforms not only in the wall thickness direction but also in the height direction during neck forming. That is, the direction of deformation of the deformation texture B during neck forming is dispersed. Therefore, the deformed texture B has a small contribution to the formation of microcracks on the surface of the can wall.

The integrated value of the section L of the base plate has a correlation with the degree of accumulation of the deformed texture B. The larger the integrated value of the section L of the base plate, the larger the degree of accumulation of the deformation texture B of the DI can wall. The reason for this is that the crystal grains of the orientation included in the interval L of the crystal orientation distribution function of the base plate cause crystal lattice rotation around the DI direction during deep drawing, and on the can wall surface during ironing. This is because the crystal lattice rotates about the vertical direction, and finally the crystal lattice rotates toward the deformed texture B on the can side wall. Crystal lattice rotation about the DI direction is crystal lattice rotation in the Euler angle Φ direction. Crystal lattice rotation about the direction perpendicular to the can wall surface is crystal lattice rotation in the Euler angle φ1 direction.

The integrated value of the section M of the base plate has a correlation with the degree of accumulation of the deformed texture B. The larger the integrated value of the section M of the base plate, the larger the degree of accumulation of the deformation texture B of the DI can wall. The reason is that the crystal grains of the orientation included in the interval M of the crystal orientation distribution function of the base plate cause crystal lattice rotation around the axis perpendicular to the can wall surface during deep drawing, and ironing. This is because the crystal lattice rotates around the axis perpendicular to the can wall surface, and finally crystal lattice rotates toward the deformed texture B on the can wall surface. These crystal lattice rotations about the direction perpendicular to the can wall surface, which occur during deep drawing and ironing, are crystal lattice rotations in the Euler angle φ1 direction. Compared to the integral value of the section L, the integral value of the section M has a more significant correlation with the degree of accumulation of the deformed texture B. Note that the sections L and M also include the Goss orientation.

Therefore, by decreasing the integral value of the section K and increasing the integral value of the section M in the base plate, it is possible to form a structure that suppresses the formation of microcracks in the can wall after DI forming. Further, in the base plate, by lowering the integral value of section K and increasing the integral value of section L and section M, it is possible to further form a structure that suppresses the formation of microcracks in the can wall after DI forming. can.

When the integral value of section K is 120 or less, deformation in the wall thickness direction during neck forming is reduced, and microcracks are less likely to occur on the surface of the can wall. As a result, curl cracking is less likely to occur. When the integral value of the interval M is 80 or more, the deformation direction of the crystal grains during neck forming is less likely to be localized in the same direction, and microcracks are less likely to occur on the surface of the can wall. As a result, curl cracking is less likely to occur. When the integral value of the interval L is 80 or more, the deformation direction of the crystal grains during neck forming becomes more difficult to localize in the same direction, and microcracks are more difficult to occur on the surface of the can wall. As a result, curl cracking is more difficult to occur.
Integral values for intervals K, L, and M can be measured as follows. Among the surfaces of the measurement sample, the surface to be measured is polished. The polishing depth is 25% of the plate thickness of the measurement sample. The Schultz reflection method (α=15° to 90°, β=0° to 360°) is performed on the polished measurement sample using an X-ray diffractometer to obtain an incomplete pole figure. From the incomplete pole figure, the crystal orientation distribution function f(φ1, φ, φ2) is determined by a series expansion method with an expansion order of 22nd. Analysis software "Standard ODF" marketed by Norm Engineering Co., Ltd. is used to determine the crystal orientation distribution function. The principle of determining a crystal orientation distribution function from an incomplete pole figure is known, and is disclosed in, for example, the following publications.

Known Literature: Hiroshi Inoue, Naoji Inakasu: Journal of the Japan Institute of Metals, 58 (1994), 892-898.
The integral value IK of the section _K can be calculated by the following formula (1).

式（１）におけるｆ（φ_１、Φ、φ_２）は結晶方位分布関数である。φ_１ｉは式（２）により表される。

f(φ ₁ , φ, φ ₂ ) in Equation (1) is the crystal orientation distribution function. φ _1i is represented by equation (2).

式（１）におけるオイラー角φ_１、Φ、φ_２の単位はそれぞれ、「°」である。式（１）におけるｎは数値積分区間の分割数である。Δφ_１は２５／ｎである。式（１）におけるｎの値は５である。

The units of the Euler angles φ ₁ , φ, and φ ₂ in Equation (1) are "°". n in equation (1) is the division number of the numerical integration interval. Δφ ₁ is 25/n. The value of n in equation (1) is five.

The integral value I _L of the section L can be calculated by the following equation (3).

式（３）におけるｆ（φ_１、Φ、φ_２）は結晶方位分布関数である。Φ_ｉは式（４）により表される。

f(φ ₁ , φ, φ ₂ ) in Equation (3) is the crystal orientation distribution function. Φ _i is represented by Equation (4).

式（３）におけるオイラー角φ_１、Φ、φ_２の単位はそれぞれ、「°」である。式（３）におけるｎは数値積分区間の分割数である。ΔΦは４５／ｎである。式（３）におけるｎの値は９である。

The units of the Euler angles φ ₁ , φ, and φ ₂ in Equation (3) are “°”. n in equation (3) is the number of divisions of the numerical integration interval. ΔΦ is 45/n. The value of n in equation (3) is nine.

The integral value I _M of the section M can be calculated by the following equation (5).

式（５）におけるｆ（φ_１、Φ、φ_２）は結晶方位分布関数である。φ_１ｉは式（６）により表される。

f(φ ₁ , φ, φ ₂ ) in Equation (5) is the crystal orientation distribution function. φ _1i is represented by equation (6).

式（５）におけるオイラー角φ_１、Φ、φ_２の単位はそれぞれ、「°」である。式（５）におけるｎは数値積分区間の分割数である。Δφ_１は３５／ｎである。式（５）におけるｎの値は７である。

The units of the Euler angles φ ₁ , φ, and φ ₂ in Equation (5) are “°”. n in equation (5) is the division number of the numerical integration interval. Δφ ₁ is 35/n. The value of n in equation (5) is seven.

3. Tensile strength The tensile strength of the aluminum alloy plate of the present disclosure is 280 MPa or more and 330 MPa or less. When the tensile strength is 280 MPa or more, the can body strength after molding is increased. When the tensile strength is 330 MPa or less, it is less likely to break. The breaking of the can body is a phenomenon in which the can body is broken during can making.

The method for measuring tensile strength is the method specified in JIS-Z-2241. The higher the cold rolling rate when producing the aluminum alloy plate of the present disclosure, the higher the tensile strength. The higher the Mn content in the aluminum alloy plate of the present disclosure, the higher the tensile strength. The higher the Cu content in the aluminum alloy plate of the present disclosure, the higher the tensile strength. The higher the content of Mg in the aluminum alloy plate of the present disclosure, the higher the tensile strength.

4. Area ratio of α-Al-Fe-Mn-Si intermetallic compound with an equivalent circle diameter of 0.5 μm or more In the aluminum alloy plate of the present disclosure, α-Al-Fe-Mn- with an equivalent circle diameter of 0.5 μm or more The area ratio of the Si-based intermetallic compound (hereinafter referred to as the α-phase area ratio) is preferably 2.0% or more.

When the α-phase area ratio is 2.0% or more, the aluminum alloy sheet of the present disclosure deforms more evenly during neck forming. Moreover, when the area ratio of the α phase is 2.0% or more, the formability of the aluminum alloy sheet of the present disclosure is improved.

When the area ratio of the α phase is 2.0% or more, the reason why the above effect is exhibited is presumed as follows. An α-Al-Fe-Mn-Si based intermetallic compound having an equivalent circle diameter of 0.5 μm or more hinders movement of crystal grains during plastic deformation and suppresses deformation of the texture in a specific direction. Therefore, when the α-phase area ratio is 2.0% or more, the aluminum alloy sheet of the present disclosure deforms more uniformly during neck forming.

The α-Al-Fe-Mn-Si intermetallic compound having an equivalent circle diameter of 0.5 μm or more improves the lubricity between the aluminum alloy plate of the present disclosure and the mold. As a result, when the area ratio of the α phase is 2.0% or more, the formability of the aluminum alloy sheet of the present disclosure is improved.

The α-phase area ratio can be measured by the following method. Among the surfaces of the measurement sample, the surface to be measured is polished. The depth of polishing shall be 1% of the plate thickness of the measurement sample. The polished surface is observed using SEM-COMPO to obtain 10 fields of view. The magnification of SEM-COMPO is 500 times. In 10 fields of view, the area of white contrast particles having an equivalent circle diameter of 0.5 μm or more (hereinafter referred to as white contrast area) is determined using the image analysis software “Azo-kun”. The area ratio of α-phase is calculated by dividing the white contrast area by the total area of 10 fields of view. Since the α-Al-Fe-Mn-Si intermetallic compound contains Fe and Mn, which are elements heavier than the matrix Al, it is observed as particles with white contrast in the SEM-COMPO image.

5. Method for Producing Aluminum Alloy Plate of Present Disclosure The aluminum alloy plate of the present disclosure can be produced, for example, as follows. An aluminum alloy having a composition corresponding to the aluminum alloy plate of the present disclosure is subjected to semi-continuous casting (DC casting) according to a conventional method to produce an ingot.

Next, the surface of the ingot is chamfered. Next, the ingot is put into a soaking furnace and homogenized. Homogenization is preferably carried out at elevated temperatures. It is preferable to perform the homogenization treatment for a long time. Due to the homogenization treatment, the Al ₆ Mn intermetallic compound crystallizes and transforms into the α phase.

The temperature in the homogenization treatment is preferably 520°C or higher and 620°C or lower. The homogenization time is preferably 1 hour or more and 5 hours or less. When the temperature in the homogenization treatment is 520° C. or higher, the transformation of the crystallized substance into the α-phase proceeds sufficiently. When the temperature in the homogenization treatment is 620° C. or less, local melting of the aluminum alloy hardly occurs.

When the homogenization treatment time is 1 hour or longer, the crystallized substance is sufficiently transformed into the α-phase. When the homogenization time exceeds 5 hours, the effect of the homogenization treatment is saturated.
Next, the ingot subjected to the homogenization treatment is subjected to hot rolling. Hot rolling includes rough rolling and finish rolling. Rough rolling is a process of processing an ingot into a plate material having a thickness of about several tens of millimeters by reverse rolling. Finish rolling is a process of reducing the thickness of the sheet material to about several millimeters by tandem rolling or the like and winding it into a coil. A member wound into a coil is hereinafter referred to as a hot-rolled coil. Next, the hot-rolled coil is cold-rolled. In cold rolling, the steel is rolled thinly until the plate thickness reaches the product plate thickness.

For each of the final pass of rough rolling and the final pass of finish rolling, the Z value represented by the following equation (7) can be calculated. When finish rolling is tandem rolling, the final pass of finish rolling is rolling at the final stand.

式（７）において、εはひずみ速度である。Ｑは熱間加工の活性化エネルギーである。Ｑの値は１５６ｋＪ／ｍｏｌである。Ｒは気体定数である。Ｒの値は８．３１４ＪＫ^－１ｍｏｌ^－１である。Ｔは加工温度である。

In equation (7), ε is the strain rate. Q is the activation energy of hot working. The value of Q is 156 kJ/mol. R is the gas constant. The value of R is 8.314JK ⁻¹ mol ⁻¹ . T is the processing temperature.

The strain rate ε is calculated by the following formula (8).

式（８）において、ｎは圧延ロールの回転速度（ｒｐｍ）である。ｒは圧下率である。Ｒ_Ａはロール半径である。Ｈ_０は圧延入側の板厚である。

In equation (8), n is the rotation speed (rpm) of the rolling rolls. r is the rolling reduction. _RA is the roll radius. _H0 is the plate thickness at the entry side of rolling.

The Z-value is a measure of the amount of strain accumulated during hot working. The larger the Z value, the easier the recrystallization. The integrated value of the section K has a negative correlation with the degree of accumulation of the recrystallized structure in the section from the Cube orientation to the Goss orientation after finish rolling. The reason for this is that the greater the degree of accumulation in the section from the Cube orientation to the Goss orientation of the finished rolled sheet, the more the development of the rolling texture accompanying cold rolling is suppressed, and the integral value of the section K is suppressed.

The integrated value of the section L and the section M has a positive correlation with the degree of accumulation of the recrystallized structure in the section from the Cube orientation to the Goss orientation after finish rolling. The reason is that the crystal grains contained in the section between the Cube orientation and the Goss orientation of the finished rolled sheet change from the Cube orientation to the Goss orientation and from the Goss orientation to the Brass orientation (φ ₁ = 30 °, Φ = 45°, φ ₂ = 0°), and the integral value of section L and the integral value of section M increase. Note that the section L includes the Cube orientation and the Goss orientation. The section M includes a Goss orientation and a Brass orientation.

In the hot-rolled coil, the material structure is recrystallized by residual heat after winding. As a result, the accumulation of Cube orientation to Goss orientation in the recrystallized structure after finish rolling becomes stronger. As the rolling texture develops without recrystallization in rough rolling, the accumulation of Cube orientation to Goss orientation becomes stronger due to recrystallization after finish rolling.

That is, the lower the Z value of the final pass of rough rolling and the larger the Z value of finish rolling, the smaller the integrated value of section K and the larger the integrated values of sections L and M. For example, the Z value of the final pass of rough rolling can be adjusted to satisfy the equation logZ<12.5. In this case, recrystallization in the final pass of rough rolling can be suppressed.

Further, for example, the Z value of finish rolling can be adjusted so as to satisfy the formula of logZ>14.7, and the processing temperature of finish rolling can be set to 330° C. or higher. In this case, the material structure is sufficiently recrystallized and accumulated in the Cube orientation to the Goss orientation.

Cold rolling may be either single rolling or tandem rolling. As the cold rolling reduction decreases, the integral value of section K increases, and the integral values of section L and section M decrease. Therefore, the smaller the cold rolling rate, the less likely curl cracks will occur.

The higher the cold rolling rate, the higher the tensile strength of the aluminum alloy plate of the present disclosure. When the cold rolling rate is high, it is preferable to increase the accumulation of Cube orientation to Goss orientation in the hot rolling stage.
The cold rolling rate is preferably 80% or more and 90% or less. When the cold rolling rate is 80% or more, the tensile strength of the aluminum alloy sheet of the present disclosure is high. Further, when the cold rolling rate is 80% or more, the rigidity of the molded can increases. When the cold rolling rate is 90% or less, the integrated value in the section K is unlikely to become excessively large. As a result, curl cracking can be suppressed.

In the method for producing an aluminum alloy plate of the present disclosure, for example, annealing may be performed before and after cold rolling or between passes, as long as the aluminum alloy plate of the present disclosure exhibits the effects.
6. Example (6-1) Production of Aluminum Alloy Plate Aluminum alloy plates S1 to S36 shown in Table 1 were produced. The manufacturing method is as follows.

まず、半連続鋳造法により、鋳塊を製造した。鋳塊の組成は表１に示すとおりである。鋳塊の厚さは７００ｍｍである。鋳塊は、不可避的な不純物元素を０．０３質量％含む。次に、鋳塊の４面を面削した。次に、鋳塊を炉に入れ、表１に示す条件で均質化処理を行った。表１のうち、均質化処理の列に記載されている温度は、均質化処理の温度である。表１のうち、均質化処理の列に記載されている時間は、均質化処理の時間である。

First, an ingot was produced by a semi-continuous casting method. The composition of the ingot is as shown in Table 1. The thickness of the ingot is 700 mm. The ingot contains 0.03% by mass of unavoidable impurity elements. Next, four faces of the ingot were chamfered. Next, the ingot was placed in a furnace and homogenized under the conditions shown in Table 1. In Table 1, the temperature described in the column of homogenization treatment is the temperature of the homogenization treatment. In Table 1, the time described in the column of homogenization treatment is the time of homogenization treatment.

Next, the ingot was discharged from the furnace and hot rolling was started immediately. The hot rolling mill used at this time has a reverse hot rough rolling mill and a tandem hot finishing mill. The Z value of the final pass of reverse hot rough rolling was controlled to the value shown in Table 1. Also, the Z value at the last stand of the tandem hot finish rolling was controlled to the value shown in Table 1.

Next, cold rolling was performed. The final sheet thickness after cold rolling was 0.280 mm. The cold rolling reduction in cold rolling was set to the values shown in Table 1 by adjusting the plate thickness after hot finish rolling.
(6-2) Evaluation of aluminum alloy plate A No. 5 test piece specified in JIS-Z-2241 was prepared from the produced aluminum alloy plate. The specimen extends in a direction that forms an angle of 0° with respect to the rolling direction. This test piece was subjected to a tensile test according to JIS-Z-2241 to measure the tensile strength. Table 1 shows the measurement results of the tensile strength.

In the produced aluminum alloy plate, the integral values of the sections K, L, and M were measured by the measurement method described above. RINT-2500V/PC manufactured by Rigaku was used as an X-ray diffractometer. Table 1 shows the measurement results of the integral values of the sections K, L, and M.

In the produced aluminum alloy plate, the area ratio of the α phase was measured by the above-described measuring method. Table 1 shows the measurement results of the α-phase area ratio.
A blank plate with a diameter of 140 mm was punched from the produced aluminum alloy plate. Next, a can body having a diameter of 66 mm was DI-formed from the blank plate. Next, the flange portion of the can body was neck-formed until the diameter reduction ratio reached 40%. Next, the tip of the neck portion was expanded by 10% to complete the can. The molding that expands the tip of the neck portion by 10% is molding that simulates curl molding. 100 cans were produced for each of S1-S36 in the manner described above.

The tip of the neck portion was observed, and the expandability was evaluated according to the following criteria. Table 1 shows the evaluation results.
A: No breakage was observed in any of the 100 cans.
◯: Breakage was observed in only 1 can out of 100 cans.

x: Breakage was observed in 2 or more cans out of 100 cans.
S1 to 5, 7, 8, 10 to 12, 15 to 17, 20, 21, 24 to 27, 29, and 34 had good tube expandability and tensile strength in the range of 280 MPa or more and 330 MPa or less. .

In particular, in S8, the area ratio of the α phase was 2.0% or more because the Fe content was large. As a result, the pipe expandability was even better.
In particular, in S12, the content of Cu was moderately high, so the tensile strength was even higher within the range of 330 MPa or less.

In particular, in S16 and S17, the area ratio of the α phase was 2.0% or more because of the high content of Mn. As a result, the pipe expandability was even better.
In particular, in S24, since the area ratio of the α phase was 2.0% or more, the pipe expandability was further excellent.

In S6, many cracks occurred at the tip of the neck portion, and the evaluation result of tube expandability was x. It is presumed that the reason for this is that the Si content was too high, so that recrystallization did not occur in the finish rolling and the desired texture could not be obtained.

In S9, since the Fe content was too high, coarse crystallized substances were generated and could not be used as a product.
In S13, the tensile strength was excessively high because the Cu content was too high. As a result, the cylinder broke at the time of DI molding.

In S14, the tensile strength was insufficient because the Mn content was too small.
In S18, since the Mn content was too large, coarse crystallized substances were generated.
In S19, the tensile strength was insufficient because the content of Mg was too small.

In S22, the Mg content was too high, resulting in excessively high tensile strength. As a result, the cylinder broke at the time of DI molding.
In S23, since the homogenization temperature was too high, local melting occurred and the product was not obtained.

In S28, 32, and 35, the evaluation result of tube expandability was x. It is presumed that the reason for this is that the desired texture could not be obtained because the Z value of the final pass of rough rolling was large.
In S30 and S36, the evaluation result of tube expandability was x. It is presumed that the reason for this is that the Z value of the final tandem of the finish rolling was small, so that the desired texture could not be obtained.

In S31, since the cold rolling rate was low, the tensile strength was insufficient.
In S33, the cold rolling rate was too high, resulting in excessively high tensile strength. As a result, the cylinder broke at the time of DI molding.

7. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made.

(1) A function of one component in each of the above embodiments may be assigned to a plurality of components, or a function of a plurality of components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added, replaced, etc. with respect to the configuration of the other above embodiments. It should be noted that all aspects included in the technical idea specified by the wording in the claims are embodiments of the present disclosure.

(2) In addition to the aluminum alloy plate described above, the present disclosure can also be realized in various forms, such as a system using the aluminum alloy plate as a component and a method for manufacturing an aluminum alloy plate.

Claims (3)

0.50% by mass or less of Si, 0.7% by mass or less of Fe, 0.3% by mass or less of Cu, 0.4% by mass or more and 1.5% by mass or less of Mn, and 0.7% by mass % or more and 1.5% by mass or less of Mg, with the balance being Al and unavoidable impurities,
The integral value of the crystal orientation distribution function in the interval of φ1 = 65° to 90°, φ = 30°, and φ2 = 45° is 120 or less,
The integral value of the crystal orientation distribution function in the interval of φ1 = 0 to 35°, φ = 45°, and φ2 = 0° is 80 or more,
An aluminum alloy plate having a tensile strength of 280 MPa or more and 330 MPa or less. The aluminum alloy plate according to claim 1,
The Si content is 0.45% by mass or less,
An aluminum alloy plate whose crystal orientation distribution function has an integral value of 80 or more in the intervals of φ ₁ =0°, Φ=0° to 45°, and φ ₂ =0°. The aluminum alloy plate according to claim 1,
The Si content is 0.1% by mass or more and 0.45% by mass or less,
Fe content is 0.3% by mass or more and 0.7% by mass or less,
Cu content is 0.05% by mass or more and 0.3% by mass or less,
The content of Mn is 0.7% by mass or more and 1.5% by mass or less,
the crystal orientation distribution function has an integral value of 80 or more in the interval of φ ₁ = 0°, Φ = 0° to 45°, and φ ₂ = 0°;
An aluminum alloy plate having an area ratio of 2.0% or more of an α-Al-Fe-Mn-Si intermetallic compound having an equivalent circle diameter of 0.5 µm or more.

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