JPH07150283A - Aluminum alloy thin slab and its production - Google Patents

Abstract

PURPOSE:To produce a slab capable of simply producing an Al alloy thin sheet excellent in formability with less rolling stages by directly casting the molten metal of an Al alloy having a specified compsn. into a thin slab and rapidly cooling the same. CONSTITUTION:The molten metal 5 of an Al alloy having a compsn. contg., by weight, <0.30% Si, <0.7% Fe, <0.25% Cu, 0.8 to 1.3% Mg and <0.25% Zn, satisfying the relationship of 1.7%<=Fe+1.07Mn<=3.0%, and the balance Al is cast into the space of both casting rolls 1-1 and 1-2 of a vertical twin roll type continuous casting device, the casting rolls are rotated respectively in the direction of the arrows 8, the Al alloy molten metal 5 is rapidly cooled at a cooling rate of 10<2> to 10<4> deg.C/sec or above, and a thin slab 6 having <=10mm thickness is continuously cast. The Al alloy slab contg. intermetallic compounds such as MnFeAl6 having >=4mum diameter equivalent to a circle by >=500 pieces per mum<2> and capable of producing a thin Al alloy sheet of about 0.4mm thickness equivalent to JISH4000 alloy number 3004 and excellent in ironing properties and forming properties with less producing stages is produced.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention is JIS H 4000 alloy No. 30.
TECHNICAL FIELD The present invention relates to an aluminum alloy thin cast piece suitable for producing a thin plate equivalent to 04 and a method for producing the same.

[0002]

[Prior Art] JIS H 4000 Alloy No. 3004 (Alloy 300 below
The aluminum alloy (abbreviated as 4) is widely used for food cans because it has excellent formability. However, in the past, since a large slab with a plate thickness of 200 mm or more was once cast and then rolled, for example, a plate thickness of 0.4 mm
When manufacturing the thin plate, there is a problem that a lot of man-hours are required for rolling and the manufacturing cost of the thin plate is high.

[0003]

If a thin slab having a plate thickness of 10 mm or less can be manufactured, a thin plate of alloy 3004 can be manufactured at a low cost by a simple process. The present invention is
It is an object to provide a thin slab having a thickness of 10 mm or less, which is suitable for manufacturing a thin plate for a food can corresponding to alloy 3004, and a method for manufacturing the thin slab.

[0004]

SUMMARY OF THE INVENTION The present invention is based on the weight percentage of ingredients.
And Si <0.30, Fe <0.7, Cu <0.25, M
g: 0.8 to 1.3, Zn <0.25 and 1.7 ≦ Fe +
Satisfy 1.07Mn ≦ 3.0, the balance being an aluminum alloy consisting essentially of Al, an equivalent circle diameter contains more intermetallic compounds 4 [mu] m 500 months / mm ² or more, the thickness is 10mm or less It is a thin aluminum alloy slab.

Further, according to the present invention, the molten aluminum alloy having the above-mentioned components is poured into a mold having a closest distance between the opposite long sides of the mold of 10 mm or less, and a temperature of 10 ² ° C./sec.
A method for producing an aluminum alloy thin slab, which comprises cooling at a cooling rate of 0 ⁴ ° C / sec to solidify.

In the present invention, the molten metal is poured into a mold in which the closest distance between the opposite long sides of the mold is 10 mm or less and the plate thickness is 10 m.
A thin cast piece of an aluminum alloy of m or less is manufactured. In the present invention, the apparatus for producing the cast piece is not particularly limited, but the cast piece can be easily manufactured by using, for example, the vertical twin roll type continuous casting machine shown in FIG.

In FIG. 1, the thickness t of the cast slab 6 to be manufactured (10 m
Two cylindrical casting rolls 1-1 and 1-2 are arranged horizontally and parallel to each other with a gap corresponding to (m or less), and rotated in the direction of arrow 8. At both ends of the casting roll, side dams 7 are arranged in close contact with the side faces of the casting roll. When the molten metal 5 is poured into the pool 2 surrounded by the upper surface of the casting roll and the side dam 7,
The molten metal is solidified on the casting rolls 1-1 and 1-2 3-
1, 3-2 are formed, and this solidified shell grows while following the rotation of the casting rolls, and is integrated at the position (kiss point) 4 where the gap between both casting rolls is the minimum, and the slab 6 is formed. Will be taken out.

According to the vertical twin roll type continuous casting method of FIG. 1, the closest distance between the molten long sides of the molten metal is 10 m.
It is possible to easily produce a slab having a plate thickness of 10 mm or less by pouring into a mold of m or less. According to this vertical twin roll continuous casting method, when the plate thickness is 10 mm or less, the cooling rate of the slab is usually 10 ² ° C / sec to 10 ⁴ ° C / sec.

According to the knowledge of the present inventors, the plate thickness is 10 m.
In the thin cast piece of the aluminum alloy having a length of m or less, when an intermetallic compound having a long side of 4 μm or more was contained at a concentration of 500 pieces / mm ² or more, a cold rolled thin plate produced using this cast piece was excellent. Has ironing properties. If the size of the intermetallic compound is smaller than 4 μm (equivalent circle diameter is 4 μm), or if the precipitation density is less than 500 pieces / mm ² , seizure or the like occurs during ironing, which is not preferable. As the intermetallic compound of the present invention, MnFeAl ₆ ,
Examples thereof include MnAl _{6 and} AlMnFeSi.

In the present invention, the aluminum component is 1.7
Adjust to ≦ Fe + 1.07 Mn ≦ 3.0. Although the present invention aims to manufacture a slab having a thin plate thickness, a thin plate thickness inevitably increases the cooling rate of the slab. Therefore, unless special measures are taken, due to this large cooling rate, the size of the intermetallic compound becomes a fine size of less than 4 μm, and the precipitation density becomes less than 500 pieces / mm ² , which causes seizure during ironing. It is easy to generate

FIG. 2 shows that in an aluminum alloy equivalent to alloy 3004, (Fe + 1.07Mn) and the cooling rate are 4 μm.
It is explanatory drawing which shows the effect which it has on the precipitation of the intermetallic compound of m or more. As shown in FIG. 2, the intermetallic compound of 4 μm or more has a larger precipitation density as the cooling rate becomes slower,
Similarly, the larger (+1.07 Mn), the larger the precipitation density.

In the molten metal having (Fe + 1.07Mn) of less than 1.7, the intermetallic compound does not crystallize during cooling until the temperature reaches the eutectic temperature because the content of components does not reach the eutectic point during solidification. In addition, α-aluminum crystallizes, and the intermetallic compound precipitates for the first time at a temperature below the eutectic temperature. In the case of large slabs, the cooling rate is slow, so intermetallic compounds that precipitate at a temperature below the eutectic temperature also grow to a sufficient size, but in the case of thin slabs, the cooling rate is high, so The intermetallic compound that precipitates below the crystal temperature is fine and the amount of precipitation is small.

Since the melt having (Fe + 1.07Mn) of 1.7 or more contains a component having a eutectic point or higher, an intermetallic compound crystallizes during cooling until the eutectic temperature is reached, resulting in eutectic temperature. Α-aluminum crystallizes out after reaching. That is, the intermetallic compound crystallizes directly from the molten metal until the eutectic temperature is reached.
The intermetallic compound crystallized from the molten metal has a size of 4 μm (equivalent circle diameter of 4 μm) or more, and the amount of precipitation is 500 pieces / m.
Many are above m ² . When this intermetallic compound having a diameter of 4 μm (equivalent circle diameter of 4 μm) or more is contained at a precipitation density of 500 pieces / mm ² or more, the cold rolled thin plate has excellent ironing workability. However, when (Fe + 1.07Mn) exceeds 3.0,
Cracks and the like are likely to occur during food can forming processing. For these reasons, in the present invention, (Fe + 1.07Mn) is added to 1.7-3.
Set to the range of 0.

In the present invention, the weight percent of the components is Si <0.3.
0, Fe <0.7, Cu <0.25, Mg: 0.8-1.
3, Zn <0.25, but the content of these components other than (Fe + 1.07Mn) is the content of the components corresponding to alloy 3004, and the performance according to alloy 3004 is the same as that of the aluminum plate. Given to.

As described above, the plate thickness is 10 mm or less,
In the case of a slab of Alloy No. 3004 or a component corresponding to Alloy 3004, the cooling rate during casting is 10 ² ° C / sec.
Since it is high at 10 ⁴ ° C / sec, the precipitation amount of the intermetallic compound having an equivalent circle diameter of 4 µm or more is small in the usual method. However, according to the present invention, (Fe + 1.07Mn) is added to 1.7-3.
When adjusted to 0, an intermetallic compound having a circle equivalent diameter of 4 μm or more can be contained at a high density even when the cooling rate is 10 ² ° C./sec to 10 ⁴ ° C./sec. As a result, by using the thin aluminum alloy slab of the present invention, it is possible to produce a food can material having excellent ironing workability.

[0016]

EXAMPLES The inventors of the present invention used the vertical twin-roll type continuous casting machine described in FIG. 1 to produce various aluminum alloy thin castings having a thickness of 5.0 mm and a cooling rate different from that of (Fe + 1.07Mn). A piece was produced. Table 1 shows the specifications of the casting machine used and the casting conditions.

[0017]

[Table 1]

The thin cast piece produced was 0.36 m after CAL annealing.
cold rolled to m. This cold rolled thin plate was molded into a 350 ml can using a body maker. The results are shown in Tables 2 to 4. As shown in Tables 2 to 4, according to the present invention, it is possible to manufacture an aluminum thin plate corresponding to alloy 3004 which has good ironing workability and excellent workability.

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

According to the present invention, JIS H 4000 alloy number
It is possible to manufacture a thin slab having a thickness of 10 mm or less, which is suitable for manufacturing a thin plate having excellent ironing properties and molding properties, which is equivalent to 3004. If the thin cast piece having a thickness of 10 mm or less is used, the post-process is simplified, so that the manufacturing cost of the thin plate can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of vertical twin roll continuous casting.

FIG. 2 is a diagram illustrating conditions for depositing an intermetallic compound.

[Explanation of symbols]

1-1, 1-2: Casting roll, 2: Molten metal pool, 3
-1, 3-2: solidified shell, 4: kiss point, 5: molten metal, 6: thin cast piece, 7: side dam, 8: direction of rotation of casting roll.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C22C 1/02 501 E 503 J

Claims (2)

[Claims] 1. Si <0.30, Fe <
0.7, Cu <0.25, Mg: 0.8 to 1.3, Zn <
An aluminum alloy satisfying 0.25 and 1.7 ≦ Fe + 1.07Mn ≦ 3.0 with the balance substantially consisting of Al, and 500 or more intermetallic compounds having a circle equivalent diameter of 4 μm or more per mm ² or more. An aluminum alloy thin cast piece having a plate thickness of 10 mm or less. 2. Si <0.30, Fe <
0.7, Cu <0.25, Mg: 0.8 to 1.3, Zn <
A molten aluminum alloy satisfying 0.25 and 1.7 ≦ Fe + 1.07Mn ≦ 3.0 with the balance substantially consisting of Al is poured into a mold in which the closest distance between the opposing long sides of the mold is 10 mm or less. A method for producing an aluminum alloy thin cast piece, which comprises cooling and solidifying at a cooling rate of 10 ² ° C / sec to 10 ⁴ ° C / sec.