JP3498943B2 - Al-Mg-Si-based aluminum alloy sheet for forming with excellent surface properties - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in building materials such as roofs, interiors and curtain walls, articles, electrical parts, optical devices, transportation equipment such as automobiles, railway vehicles and aircraft, and general mechanical parts. The present invention relates to an Al-Mg-Si based aluminum alloy plate for forming, which has excellent surface properties after processing.

[0002]

2. Description of the Related Art A 6000 series (Al-Mg-Si series) aluminum alloy plate has relatively excellent corrosion resistance and formability at room temperature, and high strength can be obtained by artificial aging treatment. Suitable for applications that require thinning. An Al-Mg-Si alloy sheet is usually homogenized, hot-rolled, then annealed if necessary, and then cold-rolled to a plate having a predetermined thickness, which is solution-quenched. And then, if necessary, skin pass, stretch and the like.

When an Al-Mg-Si alloy plate is formed, it is called a ridging mark on the surface of the plate as described in JP-A-7-228956 or JP-A-8-232052. The occurrence of surface roughness is a problem. The ridging mark is a stripe-shaped unevenness that is newly formed on the plate surface when it is formed, and is parallel to the rolling direction. Especially, when the degree of working in the 90 ° direction is large with respect to the rolling direction, for example, tensioning or drawing. When processing or ironing is performed, it occurs remarkably. When this ridging mark occurs, it cannot be used as a poor appearance for applications such as interiors, camera cases, and outer panel panels for automobiles where the surface is required to be extremely beautiful. Because it becomes particularly noticeable,
Sometimes it goes to the painting process without being noticed after the molding process, and it may be recognized only after painting. In other words, it has the troublesome characteristic that it may appear only after it is made into a product.

The above-mentioned JP-A-7-228956 and JP-A-8-232052 relate to a method for preventing the occurrence of ridging marks in an Al-Mg-Si alloy plate material, the former being 350 to 450 after homogenization treatment. Cooling to a temperature of ℃, starting hot rolling, ending hot rolling at a temperature of 200 to 300 ° C., performing intermediate annealing as necessary, and then cold rolling and solution hardening. , The latter is cooled to a temperature of 450 ° C. or lower after the homogenization treatment, starts hot rolling, finishes hot rolling at a temperature of 200 to 350 ° C., and performs intermediate annealing of 350 to 420 ° C. as necessary. After that, cold rolling, solution quenching, and final heat treatment are performed.In each case, the hot rolling temperature is set low, and at the same time, the processing conditions of the other steps are strictly controlled, and And crystallographic -Position by generating a random crystal grains, is that you try to prevent the occurrence of ridging marks.

However, Japanese Unexamined Patent Publication No. 7-228956 does not disclose the amount of deformation of press working which is said to have caused no ridging marks, and Japanese Unexamined Patent Publication No. 8-232052 discloses a tension of 2% at most as a simulation of press working. Deformation has only taken place (ie, it is only intended to prevent ridging marks caused by the forming process corresponding to a tensile deformation of at most 2%). Moreover, since these prior arts do not elucidate the constitution of the plate material itself in which the ridging mark does not occur, the plate material manufactured according to the method is actually press-molded to see if the ridging mark does not occur. There is still the problem of not knowing until (or until further painting into a product).

[0006]

On the other hand, energy saving by simplifying the manufacturing process has been studied for Al-Mg-Si based aluminum alloys as the global environmental problems increase. Specifically, it is an omission of intermediate annealing after hot rolling called roughening, but there is a problem that ridging marks are easily generated by omitting the intermediate annealing and the sheet surface property after forming is deteriorated. We have found that Al-Mg-S
In the process of studying the method of preventing the occurrence of ridging marks in the i-type aluminum alloy intermediate annealing omitted material, it was found that the ridging marks can be prevented when the hot rolling end temperature is set to a relatively high temperature. It was also found that the plate material thus produced, which does not generate ridging marks, exhibits a specific internal structure state.
When the 1-Mg-Si-based aluminum alloy exhibits this microstructure state, it is not limited to the above-mentioned intermediate annealing omitted material, but also an intermediate annealed material (one in which intermediate annealing is not omitted), a hot-rolled material (as-hot-rolled material). ), Annealed material (O material), aging treated material (T5, T
The present invention has been completed by discovering that ridging marks can be prevented even with 6 materials).

[0007]

The Al-Mg-Si-based aluminum alloy plate for forming having excellent surface properties according to the present invention has Si: 0.2 to 1.8% and Mg: 0.2 to 1. 6
%, And has a macrostructure elongated in the rolling direction A
1-Mg-Si based aluminum alloy plate, plate thickness 1
The size of the macrostructure measured at the / 4 position is less than 3 mm in length (rolling direction) and less than 0.6 mm in width (direction perpendicular to rolling), and the interval between macrostructures (direction perpendicular to rolling) is 0.
It is 6 mm or more, and the macrostructure is constituted by equiaxed recrystallized grains. In this invention,
The size of the macrostructure is smaller on the plate surface than in the plate center,
It is desirable that the distance is larger on the plate surface than in the plate center. Further, instead of using the value measured at the plate thickness 1/4 portion, the value measured at the plate thickness surface portion or the plate center portion can be used. In this case, the length of the plate surface is 2m
less than m, width less than 0.2 mm, spacing 1.0 mm or more, plate central portion less than length 10 mm, width less than 1 mm, spacing 0.4
mm or more. In particular, it is desirable that the macrostructure satisfy the above size and spacing in all of the plate surface part, the plate thickness 1/4 part and the plate center part.

Here, the macrostructure is a structure that can be easily observed with the naked eye or with a magnification of about 10 times or less by polishing the surface and then electrochemically or chemically etching. Each macrostructure is composed of a group of equiaxed recrystallized grains (micrograins) having a small misorientation with each other, and particularly in the case of the ridging mark which is a subject of the present invention, these equiaxed recrystallized grains have a cube orientation. Alternatively, it has an orientation close to the cube orientation. Each macrostructure has a shape elongated in the rolling direction after hot rolling and / or cold rolling and further after solution treatment. Further, in the present invention, the equiaxed recrystallized grains, in both the plane parallel to the plate surface and the plane perpendicular to the rolling direction, the average aspect ratio of the recrystallized grains observed is within the range of 1 to 3. Means there is.
Specifically, it is as follows. 1 ≦ dL / dLT ≦ 3 1 ≦ dL / dST ≦ 3 dL; particle size measured in the length direction of the plate dLT; particle size measured in the width direction of the plate dST; particle size measured in the plate thickness direction

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The Al-Mg-Si alloy sheet according to the present invention is, for example, hot-rolled after homogenization treatment, subsequently subjected to intermediate annealing if necessary, and then cold-rolled. It is manufactured by subjecting it to a plate material having a predetermined thickness and then subjecting it to solution quenching. Especially when intermediate annealing is omitted, it is necessary to set the hot rolling end temperature to a higher temperature and recrystallize it. In this case, the recrystallized grain shape is preferably equiaxial. If hot fibers stretched in the hot rolling direction or stretched recrystallized grains remain, these structures will be macro-stretched in the rolling direction after solution heat treatment and quenching, or after cold rolling, solution heat treatment and quenching. Become an organization. But,
After solution heat treatment and quenching by terminating hot rolling in a state where equiaxed recrystallized grains are obtained, or after cold rolling, solution treatment and quenching, the macrostructure from the plate surface layer portion to the central portion The shape has a smaller length (rolling direction) and a width (rolling right-angle direction) and a wider interval (rolling right-angle direction), and has a length of 3 mm at the plate thickness 1/4 part.
Since the width is less than mm, the width is less than 0.6 mm, and the interval is 0.6 mm or more, it is possible to prevent a ridging mark generated during molding of a product plate. The reason for selecting the plate thickness 1/4 region is that it was thought that the average macrostructure size and spacing of the plate could be obtained, but even if the values measured at the plate surface region or plate center region were used, Equivalent results can be obtained.

This macrostructure is observed as an island pattern or a streak pattern that extends substantially parallel to the rolling direction (a specific method of observation will be described later). No. 1 in FIG. No. 4 of Table 1 described later. 4 is a metallographic photograph showing a macrostructure of 4 (1/4 plate thickness portion), and the macrostructure is observed as an elongated island pattern (dark areas, horizontal and bottom line segments in the photograph indicate macrostructures). Micrograins are observed inside and outside the macrostructure). In addition, No. 1 in FIG. 5
No. in Table 1 described later. 5 is a metallographic photograph showing the macrostructure of 5 (sheet thickness 1/4 site), and the macrostructure is observed as a streak pattern because of its large length (the horizontal line segment in the photo indicates the width of the macrostructure). Microstructure is observed inside and outside the tissue. When an aluminum alloy plate having a macrostructure elongated in the rolling direction is greatly deformed especially in the direction perpendicular to the rolling direction, each macrostructure is deformed as if it were a single crystal grain, and a large slip deformation is generated as compared with the surrounding structure. Therefore, it is considered that an uneven step called a ridging mark is formed in the rolling direction on the surface of the plate after forming. Therefore, if the macrostructure is small, the sliding deformation becomes small and the interval becomes wide, so that the occurrence of ridging marks can be prevented.

On the other hand, when the plate material is hot-rolled at a high temperature, the cold-rolling ratio is low, the solution temperature is too high, etc., the recrystallized grains tend to become coarse. If coarse recrystallized grains are formed, orange peel is likely to occur on the surface of the plate material due to the forming process.
It is desirable that the thickness be 5 μm or less. For that purpose, for example, the cold rolling rate of cold rolling is set to a high value, and the heating rate in the subsequent solution treatment is increased so that fine recrystallized grains can be obtained. As described above, it is possible to improve and prevent ridging marks, orange peels, and the like during molding, and to provide a plate material for molding having excellent surface properties.

Next, preferable manufacturing conditions for obtaining the above metallurgical structure will be described. Hot rolling: Through rough hot rolling and finish hot rolling, the rolling start temperature is equal to or lower than the soaking temperature (for example, 470 to 540).
It is preferable that the rolling end temperature is set to a high value such as 350 to 450 ° C. and the rolling speed is high. Thereby, instead of the hot fibers or elongated recrystallized grains elongated in the hot rolling direction at the end of hot rolling, equiaxed recrystallized grains are obtained, and in the final product plate, the plate surface portion of the material ~ It becomes possible to make the macrostructure of the plate central portion into the above-mentioned form (size and interval). A higher hot rolling finish temperature is desirable. If the hot rolling end temperature is lower than 350 ° C., the hot fibers stretched in the hot rolling direction or elongated recrystallized grains remain at the end of the hot rolling, so that the macrostructure in the final product sheet becomes large and Since the interval becomes narrow, it becomes impossible to obtain the morphology of the above macro structure. Also,
When the hot rolling finish temperature exceeds 450 ° C., coarse recrystallized grains are generated at the end of hot rolling, which causes orange peel in the final product. When the intermediate annealing is performed after the hot rolling and before the final solution treatment, sufficiently fine recrystallized grains can be obtained in the final product, so that the hot rolling end temperature is 4
There is no problem even if it exceeds 50 ° C.

Intermediate Annealing: In order to stably obtain the above-described macrostructure, intermediate annealing may be performed after the hot rolling is completed. Typical intermediate annealing conditions are holding conditions: 500 to 5
10 seconds to 10 minutes at 80 ° C, heating rate: 30 ° C / minute to 10 minutes
00 ° C / sec, cooling rate: 10 ° C / min or more up to 50 ° C. For heating, in addition to a batch furnace, in order to increase the heating rate, a glass stone furnace, a continuous annealing furnace, an induction heating furnace or the like may be used. Cold rolling: Final product plate (after final solution heat treatment and quenching)
Since the grain size of the recrystallized grains is set to 45 μm or less, the cold rolling rate is preferably 50% or more. When the above-mentioned intermediate annealing is performed, the solid solubility is high, the room temperature aging is advanced, and the work hardening degree in the cold rolling is high. Therefore, the cold rolling rate is 30%.
The above is sufficient. Solution heat treatment and quenching: Preferred solution heat treatment conditions are 4
Heating rate up to 00 ° C is 30 ° C / min or more, 400 to 53
0 ° C at 10 ° C / min or more, holding condition: 500 to 580 ° C x
10 seconds to 10 minutes. The microstructure becomes fine equiaxed recrystallized grains. Also, the individual macro organization becomes finer. For heating, in order to increase the heating rate, a glass stone furnace, a continuous annealing furnace, an induction heating furnace or the like may be used. Quenching is performed from the holding temperature to 30 ° C. at a cooling rate of 30 ° C./min or more, or from the holding temperature to a temperature of 70 to 140 ° C. at a cooling rate of 30 ° C./min or more, and at the temperature of 70 to 140 ° C. as it is. 0.5
It may be held for up to 48 hours.

On the other hand, in terms of composition, the present invention is
In addition to an aluminum alloy containing Si: 0.2 to 1.8%, Mg: 0.2 to 1.6% and the balance Al and unavoidable impurities, Zn: 0.005 to 0.005 as necessary.
1.0%, Cu: 0.005-1.0%, Ti: 0.0
01 to 0.1%, B: 1 to 300 ppm, Be: 0.
1 to 100 ppm, Mn: 1.0% or less, Cr: 0.
0.01% to 1.5% in total of 3% or less, Zr: 0.15% or less, V: 0.15% or less, or one or more types.
%, Or an aluminum alloy containing a combination thereof, Si: 0.2 to 1.8%, Mg:
It can be applied to all Al-Mg-Si based aluminum alloys containing 0.2 to 1.6%. The reason for defining the composition of the Al-Mg-Si alloy as described above is as follows.

Mg: Mg is an element that imparts strength together with Si, but if it is less than 0.2%, sufficient strength cannot be obtained by artificial aging, while if it exceeds 1.6%, the formability deteriorates. Therefore, the Mg content is in the range of 0.2 to 1.6%. Si: Si is an element that gives strength together with Mg, but if it is less than 0.2%, sufficient strength cannot be obtained by artificial aging, while if it exceeds 1.8%, the elongation becomes low and the formability deteriorates. To do. Therefore, the Si content is set to the range of 0.2 to 1.8%. In order to obtain high strength by artificial aging, M
It is desirable that the content ratio of g and Si be Si / Mg ≧ 0.65.

Zn: Zn is MgZn during artificial aging
₂ is finely and densely deposited to realize high strength.
However, if less than 0.005%, sufficient strength cannot be obtained,
On the other hand, if it exceeds 1.0%, the corrosion resistance is significantly reduced.
The content is in the range of 0.005 to 1.0%. Cu: Cu precipitates Mg ₂ Si finely and at high density during artificial aging, and realizes high strength. However, 0.0
If it is less than 05%, it has no effect, while if it exceeds 1.0%, the corrosion resistance and weldability are remarkably reduced, so the content is less than 0.1%.
The range is 005 to 1.0%. Ti: Ti is an element added for refining the crystal grains of the ingot and improving the formability, but if it is less than 0.001%, it has no effect, while if it exceeds 0.1%, it is added. Coarse crystallized products are formed and the formability is reduced. For this reason,
The Ti content is in the range of 0.001 to 0.1%.

B: B is an alloy added in order to refine the crystal grains of the ingot and improve the formability like Ti, but if it is added in an amount of less than 1 ppm, B has no effect, and 300 ppm is added.
If it is contained in an amount exceeding the above range, a coarse crystallized substance is formed and the formability is deteriorated. Therefore, the B content is in the range of 1 to 300 ppm. Be: Be is contained in an amount of 0.1 ppm or more, if necessary, in order to prevent reoxidation of the molten aluminum in the air. However, when the content exceeds 100 ppm, the material hardness increases and the formability decreases, so the Be content is 0.1 to 100.
The range is ppm.

Mn, Cr, Zr, V: These components are Al ₂₀ Cu ₂ during homogenizing heat treatment and subsequent hot rolling.
Mn ₃ , Al ₁₂ Mg ₂ Cr, Al ₃ Zr, Al ₂ Mg
₃ Dispersed particles such as Zn ₃ are generated. Since these dispersed particles have an effect of preventing grain boundary movement after recrystallization, fine crystal grains can be obtained. However, excessive addition easily forms a coarse insoluble intermetallic compound during melting and casting, which becomes a starting point of fracture during molding and causes deterioration of moldability. Further, excessive addition of Zr tends to make the microstructure needle-like, and deteriorates fracture toughness and fatigue characteristics in a specific direction, and further formability. Therefore, the addition amounts of Mn, Cr, Zr, and V are 1.0%, 0.30%, 0.15%,
0.15% or less.

Fe: Fe contained as an impurity is Al
₇ Cu ₂ Fe, Al ₁₂ (Fe, Mn) ₃ Cu ₂ , (F
e, Mn) Al _{6 and} other crystallized products are formed. These crystallized substances are harmful to the fracture toughness and fatigue characteristics, and when the Fe content exceeds 0.5%, the fracture toughness, the fatigue characteristics and the formability are remarkably reduced. 5% or less. The crystallized substance is Al ₂ Cu other than Fe-based.
₂ Mg, Al ₂ Cu ₂ , Mg ₂ Si, and the like are soluble, and it is desirable that these be sufficiently re-dissolved in the Al matrix by solution treatment and quenching. Other impurities: Ni is limited to 0.05% or less.

[0020]

EXAMPLES Examples of the present invention will be described below. Mg: 0.55%, Si: 1.2%, Mn: 0.07
%, Fe: 0.12%, Cr: 0.05%, Ni: 0.
002%, Zn: 0.05%, Cu: 0.01%, T
i: 0.02%, B: 10 ppm, Be: 30 ppm, an aluminum alloy containing the balance impurities and aluminum was melt-cast to form a 500 mm thick ingot, and then 54
After soaking at 0 ° C. for 12 hours, it was hot-rolled under various conditions shown in Table 1 to obtain a plate having a thickness of 2.5 mm. Subsequently, it was cold-rolled without intermediate annealing to obtain a plate having a thickness of 1 mm. The plate was heated to a solution temperature of 550 ° C., held for 20 seconds, and then water-quenched (cooling rate up to 50 ° C. was about 250 ° C./s). Then, after leaving it at room temperature for 3 months, sampling was carried out from the central portion of the plate width to evaluate the material properties. The results are also shown in Table 1.

[0021]

[Table 1]

The material properties shown in Table 1 were measured as follows. Morphology of macro structure ・ ・ ・ ・ Evaluation site of macro structure is plate surface (depth from initial plate surface to 0.1 mm), plate thickness 1 /
There are 3 parts, 4 parts and the plate center part. After mechanical polishing, electrolytic etching (tetrafluoroboric acid: water = 1
5: 400, voltage 30 V, solution temperature 20 to 30 ° C., etching time 60 to 90 seconds), and observation was performed using an optical microscope (using a polarizing plate, magnification 50 times).

Grain size of recrystallized grains (microcrystalline grains) ... Simultaneously with the observation of the macrostructure at the plate surface portion. The grain size was measured on the LL plane by the line intercept method in the rolling direction. One measurement line length was 500 μm, and five lines were observed per one visual field for a total of five visual fields. The aspect ratio was measured on a plane parallel to the plate surface (the same portion as the measurement of the crystal grain size) and on a plane perpendicular to the rolling direction, but in the case of this example, all of the equiaxed grains were measured. Was in range. Proof strength, elongation ... In conformity with JIS-Z2241, a tensile test was performed at a pulling speed of 5 mm / min in the LT direction (90 ° to the rolling direction) using a JIS No. 5 test piece in a normal temperature atmosphere. I asked. Presence / absence of ridging mark: JIS No. 5 test piece from product plate (longitudinal direction is perpendicular to rolling direction, parallel part length is 60 mm)
After producing, the surface was mirror-polished (Ra <0.1μ
m), 15% tensile deformation (gauge length: 50 mm) was performed as a simulation of press working, the degree of surface irregularities was observed with the naked eye, and a streak pattern (streak pattern) parallel to the rolling direction was observed. When unevenness is noticeably observed ×,
When it could not be distinguished from the ridging mark, it was evaluated as ◯. Presence / absence of orange peel ... Sample plate above (20%
After the tensile deformation), a case where a satin-finished pattern was clearly observed on the surface was evaluated as x, and a case where the satin-finished pattern was difficult to determine was evaluated as o.

As shown in Table 1, No. 1 having a macroscopic structure satisfying the requirements of the present invention and having microcrystalline grains having an equiaxed shape. 1
In Nos. 4 and 6, no ridging mark was generated. However, the grain size of the micro-grains does not satisfy the requirements of the present invention N
o. In No. 6, orange peel occurred. On the other hand, No.
In Nos. 5 and 7, the morphology of the macrostructure did not satisfy the requirements of the present invention, and ridging marks were generated.

[0025]

According to the present invention, it is possible to obtain an Al-Mg-Si system aluminum alloy plate in which ridging marks are not generated. Further, depending on the form of the macrostructure, there is an advantage that it is possible to determine whether or not a ridging mark is generated on the plate material before molding or before painting, and to determine the degree of occurrence.

[Brief description of drawings]

FIG. 1 is a metallographic photograph showing a macrostructure of an island pattern and a streak pattern observed in a plate thickness 1/4 part of a plate material.

─────────────────────────────────────────────────── --Continued front page (56) References JP-A-5-9674 (JP, A) JP-A-56-105461 (JP, A) JP-A-63-109146 (JP, A) JP 2003-518192 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 21/00-21/18 C22F 1/04-1/057

Claims (9)

(57) [Claims] 1. An Al-Mg-containing Si: 0.2 to 1.8% (weight%, the same applies hereinafter) and Mg: 0.2 to 1.6% and having a macrostructure elongated in the rolling direction. In the Si-based aluminum alloy plate, the size of the macrostructure measured at the plate thickness 1/4 part is less than 3 mm in length (rolling direction) and less than 0.6 mm in width (direction orthogonal to rolling), and the gap between macrostructures (rolling) Perpendicular direction) is 0.6 mm or more, and the macrostructure has a cube orientation or an orientation close to the cube orientation.
An Al-Mg-Si-based aluminum alloy plate for forming, which has excellent surface properties and is composed of equiaxed recrystallized grains. 2. Si: 0.2 to 1.8%, Mg: 0.2
In an Al-Mg-Si-based aluminum alloy plate having a macrostructure containing 1.6% by weight and extending in the rolling direction, the size of the macrostructure measured at the plate surface portion is less than 2 mm in length (rolling direction) and width. (Rolling right angle direction) 0.2m
less than m, the interval between the macrostructures (direction perpendicular to the rolling direction) is 1.
0 mm or more and the macrostructure has a cube orientation
Is an Al-Mg-Si-based aluminum alloy plate for forming having excellent surface properties, characterized by being composed of equiaxed recrystallized grains having an orientation close to the cube orientation . 3. Si: 0.2 to 1.8%, Mg: 0.2
In an Al-Mg-Si-based aluminum alloy plate containing ~ 1.6% and having a macrostructure elongated in the rolling direction, the size of the macrostructure measured at the plate central portion has a length (rolling direction) of less than 10 mm and a width. (Rolling right angle direction) 1mm
Less than 0.4, the spacing between macrostructures (direction perpendicular to the rolling direction) is 0.4
Der mm or more is, the macrostructure is cube orientation or
Structured by equiaxed recrystallized grains with an orientation close to the cube orientation.
Molding for Al-Mg-Si based aluminum alloy sheet having excellent surface properties, characterized by being made. 4. An Al-Mg-Si based aluminum alloy further comprising Zn: 0.005 to 1.0% and Cu: 0.0
05-1.0%, Ti: 0.001-0.1%, Al-Mg-Si for molding according to any one of claims 1 to 3, which has excellent surface properties. Series aluminum alloy plate. 5. An Al-Mg-Si based aluminum alloy further comprising B: 1 to 300 ppm and Be: 0.1 to 10.
Al-for molding, which has excellent surface properties according to any one of claims 1 to 4, characterized in that it contains 0 ppm.
Mg-Si based aluminum alloy plate. 6. An Al-Mg-Si based aluminum alloy further comprising Mn: 1.0% or less, Cr: 0.3% or less,
Zr: 0.15% or less, V: 0.15% or less, 1 type or 2 types or more 0.01-1.5% in total, It is characterized by containing in any one of Claims 1-5. Al-Mg-Si based aluminum alloy plate for forming, which has excellent surface properties. 7. The size of the macrostructure is smaller in the plate surface portion than in the plate central portion.
An Al-Mg-Si-based aluminum alloy plate for forming, which is excellent in surface properties as described in any of 6 above. 8. An Al—Mg—S that has been subjected to cold rolling and solution hardening after intermediate rolling, if necessary, after hot rolling.
An aluminum alloy plate for forming according to any one of claims 1 to 7, which is an i-based aluminum alloy plate and has excellent surface properties. 9. The aluminum alloy plate material for forming according to claim 1, wherein the grain size of the equiaxed recrystallized grains is 45 μm or less.