JP6836266B2 - Al-Mg-Si based aluminum alloy cast plate and its manufacturing method - Google Patents

Description

The present invention relates to an Al-Mg-Si based aluminum alloy cast plate and a method for producing the same.

For example, Al-Mg-Si-based aluminum alloys represented by 6000-based aluminum alloys have excellent age hardening ability. For this reason, there is an advantage that formability can be ensured by lowering the yield strength during press molding and bending, and strength (for example, yield strength) can be improved by age hardening by aging treatment at a relatively low temperature such as coating baking treatment after molding. have. Further, although the strength of the 6000 series aluminum alloy is lower than that of the 2000 series alloy, it is excellent in moldability and corrosion resistance.

Further, the Al-Mg-Si based aluminum alloy, particularly the 6000 series aluminum alloy, has a relatively small amount of alloying elements as compared with other 5000 series aluminum alloys having a large amount of alloy such as the amount of Mg. Therefore, when the scraps of these aluminum alloy plates are reused as an aluminum alloy melting material (melting raw material), it is easy to obtain an Al-Mg-Si based aluminum alloy ingot similar to the original alloy plate, etc., and it is recyclable. Is also excellent.

For this reason, it is an aluminum alloy that is attracting attention in many applications, for example, by using it as a plate material to reduce the weight of automobiles. The roll casting method is used to obtain an Al-Mg-Si-based aluminum alloy plate because an Al-Mg-Si-based aluminum alloy can be obtained at low cost and with relatively high productivity.
For example, Patent Document 1 discloses a method of obtaining an Al—Mg—Si based aluminum alloy cast plate by using a horizontal double roll method. Further, Non-Patent Document 1 discloses a method of obtaining an Al—Mg—Si based aluminum alloy cast plate in which internal cracks are suppressed by using a vertical double roll casting method and optimizing the conditions. There is.

Japanese Unexamined Patent Publication No. 10-102178

"Effect of Phase 2 Particles on Mechanical Properties of Al-Mg-Si Alloy Plates for Automotive Use" Kenji Tokuda 2007 Dissertation (Doctoral) Dissertation (Tokyo Institute of Technology)

However, in the conventional casting method including the methods shown in Patent Document 1 and Non-Patent Document 1, the obtained cast plate of Al—Mg—Si based aluminum alloy such as 6000 series alloy can be used as it is. If used (as it is after casting), there is a problem that cracks may occur on the surface during bending.
For example, in a conventional 6000 series alloy cast plate having a plate thickness of 10 mm or less, cracks (including minute cracks) are prevented from occurring on the surface when a 180-degree bending test according to JIS Z 224198: 2006 is performed. Was extremely difficult.

For this reason, the conventional cast plate of Al-Mg-Si-based aluminum alloy cannot be subjected to bending work with relatively strict processing conditions, and Al-Mg-Si-based aluminum that can be sufficiently bent. A cast aluminum plate was sought.

An embodiment of the present invention is intended to solve such a problem, and is a casting of an Al—Mg—Si based aluminum alloy having sufficient bending workability and suppressing crack generation during bending processing. It is an object of the present invention to provide a plate and a method for producing the plate.

Aspect 1 of the present invention is a method for producing an Al—Mg—Si based aluminum alloy cast plate by a twin roll casting method in which a pair of rotating rolls facing each other is used to supply molten metal between them and solidify them. And
The molten metal contains 90% by mass or more of Al, 0.2 to 2.0% by mass of Si, and 0.2 to 3.0% by mass of Mg.
The roll is made of copper or a copper alloy, and the peripheral speed of each of the pair of rotating rolls is 20 m / min or more and 150 m / min or less.
This is a method for manufacturing an Al—Mg—Si based aluminum alloy cast plate in which the set of rotating rolls is pressed at 0.8 kN / mm or more and 2.0 kN / mm or less.

In aspect 2 of the present invention, the molten metal contains Si: 0.2 to 2.0% by mass and Mg: 0.2 to 3.0% by mass.
If necessary, Fe: 1.0% by mass or less (excluding 0% by mass), Mn: 1.4% by mass or less (excluding 0% by mass), Cr: 0.35% by mass or less (0% by mass) % Is not included), Zr: 0.3% by mass or less (not including 0% by mass), V: 0.3% by mass or less (not including 0% by mass), Ti: 0.25% by mass or less (0) Cu: 1.2% by mass or less (excluding 0% by mass), Ag: 0.2% by mass or less (excluding 0% by mass), Zn: 1.0% by mass or less (excluding 0% by mass) 0% by mass or less), Sn: 0.5% by mass or less (not including 0% by mass), Sc: 1.0% by mass or less (not including 0% by mass), B; 0.06% by mass or less 1 selected from the group consisting of (not including 0% by mass), Bi: 1.5% by mass or less (not including 0% by mass) and Pb: 2.0% by mass or less (not including 0% by mass) 1 Further containing seeds or two or more
The method for producing an Al—Mg—Si based aluminum alloy cast plate according to the first aspect, wherein the balance is composed of Al and unavoidable impurities.

Aspect 3 of the present invention is the Al—Mg—Si based aluminum alloy cast plate according to Aspect 2, wherein the molten metal satisfies one composition selected from 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy. It is a manufacturing method of.

Aspect 4 of the present invention contains at least one of Fe: 1.0 to 2.0% by mass and Cu: 1.0 to 1.2% by mass, and the other elements are 6063 alloy, 6061 alloy, and 6016 alloy. , 6022 alloy and 6111 alloy, which is the method for producing an Al—Mg—Si based aluminum alloy cast plate according to the first aspect, which satisfies one composition standard.

Aspect 5 of the present invention contains Si: 0.2 to 2.0% by mass and Mg: 0.2 to 3.0% by mass.
The thickness is 10 mm or less,
It is an Al-Mg-Si based aluminum alloy cast plate having no cracks on the surface after a 180 degree bending test conforming to JIS Z 2248.

Aspect 6 of the present invention is an automobile body sheet using the Al—Mg—Si based aluminum alloy cast plate according to claim 5.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a cast plate of an Al—Mg—Si based aluminum alloy having sufficient bending workability and suppressing the occurrence of cracks during bending processing, and a method for producing the same.

FIG. 1 is a schematic cross-sectional view showing a twin roll caster 100 used in the manufacturing method according to the embodiment of the present invention and a schematic partially enlarged cross-sectional view showing a meniscus 12a. FIG. 2 is a schematic cross-sectional view showing the bending test apparatus 200. FIG. 3 is a photograph showing an example of the surface observation result. FIG. 3 (a) is the surface observation result of Comparative Example 4-1, FIG. 3 (b) is the surface observation result of Comparative Example 4-2, and FIG. 3 (c) is the surface observation of Example 4-3. The result.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "top", "bottom", "right", "left" and other terms including those terms) are used as necessary. , The use of these terms is to facilitate the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same parts or members.

1. 1. Method for manufacturing Al-Mg-Si based aluminum alloy cast plate As a result of diligent studies by the present inventors, 90% by mass or more of Al, 0.2 to 2.0% by mass of Si, and 0.2 to 3. When manufacturing an Al-Mg-Si based aluminum alloy cast plate containing 0% by mass of Mg, the material of the roll, the peripheral speed of the roll, and the pressing force applied to the roll are properly adjusted by using the twin roll casting method. Al-Mg-Si type that can suppress the generation of cracks (including minute cracks) on the surface when bending is performed by casting an Al-Mg-Si type aluminum alloy by controlling the range. We have found that we can obtain cast aluminum alloy plates.

First, the casting apparatus used in the method for manufacturing an Al—Mg—Si based aluminum alloy cast plate according to the embodiment of the present invention will be described below.
FIG. 1 is a schematic cross-sectional view showing a twin roll caster 100 used in the manufacturing method according to the embodiment of the present invention and a schematic partially enlarged cross-sectional view showing a meniscus 12a.
The twin roll caster 100 has a set of rolls including roll 1A and roll 1B. The roll 1A and the roll 1B are separated from each other and rotate in the directions of the arrows A and B, respectively. The molten metal 10 supplied to the gap (casting cavity) between the rolls 1A and 1B comes into contact with the rotating rolls 1A and 1B, is cooled, and solidification progresses, and the solidified portion moves downward. It proceeds and is further cooled to form an Al—Mg—Si based aluminum alloy cast plate 12. In the embodiment shown in FIG. 1, the cooling after the solidified portion (including the case where the unsolidified region is included inside) is separated from the rolls 1A and 1B is air-cooled, but the cooling is not limited to this, and water cooling or the like is performed. It may be cooled by another cooling method.

In the solidification, the meniscus 12a is formed in the vicinity of the portion where the molten metal 10 contacts the roll 1A or 1B and the nozzle 3 (including the case where the molten metal 10 contacts the nozzle 3 via a mold release agent). As the meniscus 12a moves downward along the rolls 1A or 1B, cooling proceeds to form a solidified portion (the outer portion of the finally obtained Al—Mg—Si based aluminum alloy cast plate 12). Then, in the process in which the solidified portion advances downward due to the rotation of the roll 1A and the roll 1B, the entire cross section perpendicular to the casting direction is solidified to form the Al—Mg—Si based aluminum cast plate 12.

It is preferable to supply the molten metal 10 between the rolls 1A and 1B via the nozzle 3 in a state where the liquid level (hot water surface) 10a of the molten metal 10 is formed inside the nozzle 3 by using the nozzle 3. A certain amount of hydrostatic pressure is generated by the molten metal, fluctuations in the shape of the meniscus 12a can be suppressed, and more stable casting conditions can be obtained. The liquid level 10a is preferably 5 mm, more preferably 10 mm, and is located above the tip of the meniscus 12a (the upper end of the meniscus 12a in FIG. 1).
The shape of the meniscus 12a shown in FIG. 1 is merely an example, and the meniscus 12a may have a different shape depending on casting conditions such as the height of the liquid surface of the molten metal. Further, the shape of the meniscus 12a may fluctuate periodically or aperiodically due to fluctuations in casting conditions such as the height of the liquid level of the molten metal.
The nozzle 3 may be made of refractory material.
When supplying the molten metal 10 to the twin roll casters 100. The molten metal 10 is preferably at a temperature 10 ° C. to 50 ° C. higher than the liquidus temperature. As a result, more stable casting can be performed.

The twin roll caster (double roll casting apparatus) 100 shown in FIG. 1 is a vertical casting apparatus. That is, the roll 1A and the roll 1B are arranged side by side in the horizontal direction, and the molten metal 10 is usually supplied from above between the roll 1A and the roll 1B. The vertical casting apparatus is preferable because the molten metal can be easily poured between the rolls and the casting speed can be easily increased.
However, the present invention is not limited to this, and for example, a horizontal roll caster in which two rolls are arranged side by side in the vertical direction and hot water is poured from the horizontal direction between the rolls may be used. An inclined casting machine may be used in which the two rolls are arranged at an angle that is neither horizontal nor vertical.

Further, in the double roll caster (double roll type casting apparatus) 100 shown in FIG. 1, the diameters of the roll 1A and the roll 1B are the same. As a result, the peripheral speeds of the two rolls can be made the same relatively easily. However, the diameter of one roll may be larger than the diameter of the other roll.
Next, the details of the casting conditions of the Al—Mg—Si based aluminum alloy cast plate according to the embodiment of the present invention will be described.

(1) Roll Material Roll 1A and Roll 1B are made of copper or a copper alloy. As a result, high heat transfer characteristics between the molten metal 10 and the roll 1A or the roll 1B can be obtained, and the molten metal 10 can be solidified at a sufficiently fast cooling rate, and the obtained Al-Mg-Si based aluminum casting can be obtained. It is possible to prevent cracks from occurring on the surface of the plate 12 after bending.
Here, the copper alloy means an alloy containing 50% or more of copper in terms of mass ratio. Preferably, copper is contained in an amount of 90% or more by mass ratio, and more preferably copper is contained in an amount of 98% or more by mass ratio. Thereby, sufficient heat transfer characteristics can be obtained more reliably. As such a preferable copper alloy, CCM- which contains Cu ≧ 98% by mass, Cr: 0.05 to 1.5% by mass and Zr: 0.03 to 0.8% by mass, and the balance is an unavoidable impurity. Examples thereof include A alloy and CCM-B alloy.

In the present specification, "the roll is made of copper or a copper alloy" means that the portion of the roll surface in contact with the molten metal 10 is formed of copper or a copper alloy, and does not come into contact with the molten metal. The concept includes a roll whose portion (inside) is made of a material other than copper or a copper alloy and a roll having a hollow portion inside.

(2) Roll peripheral speed As described above, the roll 1A and the roll 1B rotate in the directions of the arrows A and B, respectively. The peripheral speeds of the roll 1A and the roll 1B are 20 m / min or more and 150 m / min or less. Preferably, the peripheral speeds of roll 1A and roll 1B are the same.
In order to avoid the occurrence of surface cracks after bending, the peripheral peripheral speed of the roll is usually reduced to, for example, 10 m / min. However, as described above, the present inventor uses copper or a copper alloy as the material of the roll, and as described in detail below, a pair of rolls (rolls 1A and 1B) is used at 0.8 kN / mm or more. By pressing at 2.0 kN / mm or less and setting the roll peripheral speed to 20 m / min or more, the thickness of the solidified layer during casting is stabilized and the load fluctuation on the roll is reduced, which results in bending. It was found that the occurrence of surface cracks could be suppressed. As described above, the fact that casting can be performed at a roll peripheral speed of 20 m / min or more means that high-speed double roll casting is possible, and high productivity can be realized.

On the other hand, when the peripheral speed of the roll exceeds 150 m / min, it becomes difficult to keep the contact state between the molten metal and the roll uniform due to the molten metal head pressure. Therefore, in order to further increase the molten metal head pressure, it is necessary to increase the wall height of the nozzle or apply gas pressure, which is not practical because the manufacturing apparatus becomes large and complicated.

(3) Roll Pressing A set of rolls (double rolls) composed of rolls 1A and 1B is pressed as shown by an arrow P in FIG. More specifically, a set of rolls is pressed in a direction that narrows the distance between them. The pressing force is 0.8 kN / mm or more and 2.0 kN / mm or less. The pressing force is obtained by dividing the load applied to the roll by the length of the roll (width, length in the direction perpendicular to the paper surface of FIG. 1).
By setting the pressing force to 0.8 kN / mm or more, the shape of the solidified portion is stabilized at a roll peripheral speed of 20 m / min or more, and when the obtained Al-Mg-Si based aluminum alloy cast plate is bent. It is possible to suppress the occurrence of cracks on the surface.

On the other hand, if the pressing force exceeds 2.0 kN / mm, the roll surface becomes rough in a short time during casting, and unevenness is transferred to the surface of the obtained Al-Mg-Si based aluminum alloy casting plate, which is transferred. Due to the unevenness, surface cracks occur during bending. For example, when comparing the roll surfaces after casting a 6022 alloy plate at a roll peripheral speed of 60 m / min, when the pressing force is 2.0 kN / mm, the roll surface is hardly roughened, whereas the pressing force is 2. In the case of 5 kN / mm, it has been confirmed that the roll surface becomes rough and uneven in a short time.

The roll may be pressed by using a known device such as a spring or a damper. Although the pressing force P is applied to both the roll 1A and the roll 1B in FIG. 1, the pressing force P is not limited to this, and for example, the rotation axis of either the roll 1A or the roll 1B is set in the horizontal direction of FIG. It may be fixed so as not to move, and the pressing force P may be applied only to the other of the roll 1A and the roll 1B.

(4) Alloy Composition The Al-Mg-Si based aluminum alloy cast plate according to the embodiment of the present invention contains 90% by mass or more of Al, 0.2 to 2.0% by mass of Si, and 0.2 to 3%. It contains 0.0% by mass of Mg, preferably 95% by mass or more of Al, 0.2 to 2.0% by mass of Si, and 0.2 to 2.0% by mass of Mg.
In one preferred embodiment, the balance is an unavoidable impurity.
In another preferred embodiment, in addition to the unavoidable impurities, any one or more elements that do not impair castability may be included. That is, when the cast material cast under the casting conditions satisfying the conditions specified in "(1) roll material", "(2) roll peripheral speed" and "(3) roll pressing" is bent, the surface is exposed. As long as an Al—Mg—Si based aluminum alloy cast plate can be obtained without causing cracks, the balance may contain any one or more elements other than unavoidable impurities.

As an aluminum alloy that satisfies such an alloy composition and is widely used, there is a 6000 series alloy defined by JIS standard and AA standard in the United States.
The 6000 series alloys are 6101 alloys and 6061 alloys and 6082 alloys whose compositions are specified in Japanese Industrial Standards JIS H 4000: 2014, and 6005A alloys, 6005C alloys and 6060 alloys whose compositions are specified in JIS H 4040: 2015. Includes alloys, 6262 alloys, 6063 alloys and 6181 alloys and 6464 alloys whose composition is specified in JIS H 4080: 2015. In addition to JIS standards, for example, AA standard 6016 alloys, 6022 alloys and 6111 alloys are also included in the 6000 series alloys.

Further, there are some definitions for the composition range that defines the entire 6000 series alloy, but in this specification, the composition range of the 6000 series alloy is defined as follows.
Si: 0.2 to 2.0% by mass and Mg: 0.2 to 3.0% by mass,
It is permissible to contain one or more selected from the following as needed,
Fe: 1.0% by mass or less (not including 0% by mass)
Mn: 1.4% by mass or less (excluding 0% by mass)
Cr: 0.35% by mass or less (excluding 0% by mass)
Zr: 0.3% by mass or less (not including 0% by mass)
V: 0.3% by mass or less (excluding 0% by mass)
Ti: 0.25% by mass or less (not including 0% by mass)
Cu: 1.2% by mass or less (not including 0% by mass)
Ag: 0.2% by mass or less (not including 0% by mass)
Zn: 1.0% by mass or less (excluding 0% by mass)
Sn: 0.5% by mass or less (not including 0% by mass)
Sc: 1.0% by mass or less (excluding 0% by mass)
B: 0.06% by mass or less (not including 0% by mass)
Bi: 1.5% by mass or less (not including 0% by mass)
Pb: 2.0% by mass or less (excluding 0% by mass)
The rest consists of Al and unavoidable impurities.

Among the 6000 series alloys, 6063 alloys, 6061 alloys, 6016 alloys, 6022 alloys and 6111 alloys are preferable in consideration of the wide range of applications.

Further, as an improved alloy of 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy, at least one of Fe: 1.0 to 2.0% by mass and Cu: 1.0 to 1.2% by mass is contained. , Other elements (that is, elements other than Fe when the content of Fe is 1.0 to 2.0% by mass, elements other than Cu when the content of Cu is 1.0 to 1.2% by mass, Fe. When 1.0 to 2.0% by mass and 1.0 to 1.2% by mass of Cu are contained, elements other than Fe and Cu) are 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy or 6111 alloy. An alloy satisfying the above composition standard can also be mentioned as a preferable composition.
The content of Fe in an amount of 1.0 to 2.0% by mass has the effect of improving ductility after roll casting, and the content of Cu in an amount of 1.0 to 1.2% by mass can improve the strength.

Since the Al—Mg—Si based aluminum alloy cast plate 12 according to the embodiment of the present invention has the above-mentioned composition, the molten metal 10 has substantially the same composition as the above-mentioned composition.

2. 2. Al-Mg-Si-based aluminum alloy cast plate The Al-Mg-Si-based aluminum alloy cast plate according to the embodiment of the present invention has the composition specified in "(4) Alloy composition" described above. Further, even if a 180-degree bending test according to JIS Z 2248: 2006 is performed, no cracks (including minute cracks) are generated on the surface.
For conventional 6000 series alloy plates with a plate thickness of 10 mm or less, which have many uses, cast plates that do not crack on the surface even after being bent 180 degrees (after casting, without heat treatment, that is, as cast) However, the Al-Mg-Si-based aluminum alloy cast plate according to the embodiment of the present invention has a plate thickness of 10 mm. It has the feature that cracks do not occur on the surface even if the 180 degree bending test according to JIS Z 2248: 2006 is performed below.
Such an Al-Mg-Si based aluminum alloy cast plate according to the embodiment of the present invention can be used for various members such as a body sheet of an automobile.
In particular, the 6000 series aluminum alloy, especially the 6022 aluminum alloy, is cast into a thin plate by the above-mentioned twin roll casting method, and the 6000 series aluminum alloy plate rolled after casting is a body sheet for automobiles (inner plate, outer plate, ceiling). ) Can be suitably used.

・ Example 1
1. 1. Sample Preparation Using the roll casters 100 outlined in FIG. 1, an Al—Mg—Si based aluminum alloy cast plate sample having the components shown in Table 1 was prepared.
As the roll 1A and the roll 1B, a roll made of a copper alloy CCM-A having a diameter of 300 mm and a width of 50 mm was used. The roll peripheral speeds of roll 1A and roll 1B were the same, and were set to 30 m / min or 90 m / min as shown in Table 2. Further, as shown in Table 2, a pressing force P of 0.2 kN / mm to 2.0 kN / mm was applied to the roll. The rotation axis of the roll 1B is fixed so as not to move in the lateral direction, and the pressing force P is applied only to the roll 1A.
The distance between the roll 1A and the roll 1B was adjusted so that the plate thickness t of the obtained sample was 3 mm.

A nozzle having a height of 200 mm and a length of 50 mm in the roll width direction was used. The molten metal 10 having a temperature 10 ° C. to 50 ° C. higher than the liquidus temperature was poured into the nozzle 3. The molten metal 10 was poured so that the liquid level 10a of the molten metal in the nozzle 3 was 50 mm or more from the tip of the meniscus 12a.

As a result, a cast material having a width of 50 mm and a thickness of 3 mm was obtained for each sample.

2. 2. Bending test and surface observation The obtained sample was subjected to a 180 degree bending test in accordance with JIS Z 2248: 2006. FIG. 2 is a schematic cross-sectional view showing the bending test apparatus 200. The obtained cast material was cut to obtain a No. 1 test piece having a length of 80 mm, a width of 50 mm, and a thickness (t) of 3 mm. The distance between the support 22 and the support 23 was set to 30 mm. The inner radius r of the tip of the push metal fitting 21 was set to 10 mm.
Then, the push metal fitting 21 is pushed in the direction of arrow F and bent to 170 °, and then both ends of the test piece are pressed against each other with a scissors having a thickness of 20 mm, which is twice the inner radius r, and bent to 180 °. It was.

With respect to the test piece after the bending test, the surface portion on the outside at the time of bending was visually observed. The surface observation results are shown in Table 2. Those with clear cracks are marked with "x", those with uneven gloss or vertical streaks corresponding to microcracks are marked with "△", those with no cracks and no microcracks. Was set to "○", and "○" was set to pass.
FIG. 3 is a photograph showing an example of the surface observation result. FIG. 3 (a) is the surface observation result of Comparative Example 4-1, FIG. 3 (b) is the surface observation result of Comparative Example 4-2, and FIG. 3 (c) is the surface observation of Example 4-3. The result.

As can be seen from Table 2, any of the example samples in which the peripheral speed of the roll is 20 m / min or more and 150 m / min or less and the pressing force of the roll is 0.8 kN / mm or more and 2.0 kN / mm or less. Also showed good results with no cracks on the surface after the bending test.
On the other hand, a comparative example that does not satisfy at least one of the peripheral speed of the roll being 20 m / min or more and 150 m / min or less and the pressing force of the roll being 0.8 kN / mm or more and 2.0 kN / mm or less. All of the samples had cracks or microcracks on the surface after the bending test.

-Example 2
An alloy in which 0.2 to 1.0% by mass of Fe is further added to the 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy of Example 1 shown in Table 2, and 0.2 Cu is further added to the 6022 alloy. A sample of the alloy to which ~ 1.0% by mass was added was prepared.
The composition of each alloy is such that the balance Al is reduced by the amount of Fe or Cu added. For example, in an alloy sample in which 0.2% by mass Fe is added to the 6063 alloy (described as "6063 + 0.2% Fe" in the table), the Fe content is 0.40% by mass, and only the amount of increase in Fe. The remaining Al is reduced, and the other elements Si, Cu, Mn, Mg, Cr, Zn and Ti are substantially the same as the values shown in Table 2.

A cast material having the same size (length 80 mm, width 50 mm, thickness 3 mm) as that of Example 1 was obtained by the method described in “1. Sample preparation” of Example 1 except that the alloy composition was different.
Then, using the obtained cast material, a bending test and a surface observation were carried out by the method described in "2. Bending test and surface observation" of Example 1.
The surface observation results are shown in Tables 3-8.
Tables 3 to 7 show the surface observation results of alloy samples in which 0.2 to 1.0% by mass of Fe was further added to 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy, respectively. The surface observation result of the sample of the alloy which added 0.2 to 1.0 mass% of Cu to the 6022 alloy is shown.

As can be seen from Tables 3 to 8, samples in which the peripheral speed of the roll is 20 m / min or more and 150 m / min or less and the pressing force of the roll is 0.8 kN / mm or more and 2.0 kN / mm or less (Example). All of the samples) showed good results with no cracks on the surface after the bending test.
On the other hand, a sample that does not satisfy at least one of the peripheral speed of the roll being 20 m / min or more and 150 m / min or less and the pressing force of the roll being 0.8 kN / mm or more and 2.0 kN / mm or less ( Comparative example samples) all had cracks or microcracks on the surface after the bending test.

1A, 1B roll 3 nozzle 10 molten metal 10a molten metal liquid level 12 Al-Mg-Si based aluminum alloy casting plate 12a meniscus 21 push metal fittings 23 support part 30 sample 100 twin roll caster 200 bending test device

Claims (4)

A method for producing an Al-Mg-Si based aluminum alloy cast plate by a twin roll casting method in which a molten metal is supplied between them and solidified by using a pair of rotating rolls facing each other.
The molten metal contains 90% by mass or more of Al, 0.2 to 2.0% by mass of Si, and 0.2 to 3.0% by mass of Mg.
The roll is made of copper or a copper alloy, and the peripheral speed of each of the pair of rotating rolls is 20 m / min or more and 150 m / min or less.
A method for producing an Al-Mg-Si based aluminum alloy cast plate in which the set of rotating rolls is pressed at 0.8 kN / mm or more and 2.0 kN / mm or less. The molten metal contains Si: 0.2 to 2.0% by mass and Mg: 0.2 to 3.0% by mass.
If necessary, Fe: 1.0% by mass or less (excluding 0% by mass), Mn: 1.4% by mass or less (excluding 0% by mass), Cr: 0.35% by mass or less (0% by mass) % Is not included), Zr: 0.3% by mass or less (not including 0% by mass), V: 0.3% by mass or less (not including 0% by mass), Ti: 0.25% by mass or less (0) Cu: 1.2% by mass or less (excluding 0% by mass), Ag: 0.2% by mass or less (excluding 0% by mass), Zn: 1.0% by mass or less (excluding 0% by mass) 0% by mass or less), Sn: 0.5% by mass or less (not including 0% by mass), Sc: 1.0% by mass or less (not including 0% by mass), B: 0.06% by mass or less 1 selected from the group consisting of (not including 0% by mass), Bi: 1.5% by mass or less (not including 0% by mass) and Pb: 2.0% by mass or less (not including 0% by mass) 1 Further containing seeds or two or more
The method for producing an Al—Mg—Si based aluminum alloy cast plate according to claim 1, wherein the balance is composed of Al and unavoidable impurities. The method for producing an Al—Mg—Si based aluminum alloy cast plate according to claim 2, wherein the molten metal satisfies one composition selected from 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy. Fe: 1.0 to 2.0% by mass and Cu: 1.0 to 1.2% by mass, and the other elements are from 6063 alloy, 6061 alloy, 6016 alloy, 6022 alloy and 6111 alloy. The method for producing an Al—Mg—Si based aluminum alloy cast plate according to claim 1, which satisfies the standard of one selected composition.

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