JPH07148557A - Production of aluminum and aluminum alloy thin cast slab by twin roll type continuous casting - Google Patents

Abstract

PURPOSE:To produce an aluminum or an aluminum alloy thin cast slab without developing local bulging and double sheets in the cast slab by using a twin roll type continuous caster. CONSTITUTION:The casting is executed so that the barrel part length W (mm) and the roll diameter D (mm) of the casting rolls 1-1, 1-2 and the pushing pressure F(kgf) in the mutual casting rolls in the twin roll type continuous caster satisfy 0.005<= F/W/sq. rt. D<=1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thin cast piece of aluminum or an aluminum alloy (hereinafter collectively referred to as aluminum and the like).

[0002]

2. Description of the Related Art FIG. 1 is an explanatory view of an example of vertical twin roll type continuous casting. Two cylindrical casting rolls 1-1 and 1-2 provided with an interval corresponding to the thickness t of the cast slab 6 to be manufactured.
Are arranged horizontally and parallel to each other. Further, side dams 7 are arranged at both ends of the casting roll in close contact with the side surface of the casting roll. The molten metal 5 is injected into the molten metal pool 2 surrounded by the upper surfaces of the casting rolls 1-1 and 1-2 and the side dam 7, and a pressing force F is applied to the casting rolls to move the casting rolls 1-1 and 1-2 by arrows. When it is rotated in eight directions, the molten metal is solidified on the casting rolls 1-1 and 1-2 by the solidified shell 3
-1, 3-2 are formed, but this solidified shell grows while moving in accordance with the rotation of the casting rolls, and is integrated at a position (kiss point) 4 where the distance between both casting rolls is the minimum. It becomes 6 and is taken out.

Although no prior art relating to vertical or inclined twin roll type continuous casting in aluminum and aluminum alloys is found, when molten metal such as aluminum is used as the molten metal 5, a cast piece 6 such as aluminum can be obtained. However, according to the knowledge of the present inventors, if a slab of aluminum or the like is cast by twin roll type continuous casting, especially at a high speed of 5 m / min or more, without special measures, the slab locally swells. (Bulging) may occur, or a slab of two plates may be generated in which the slab is separated into two pieces in the thickness direction immediately below the casting roll. If local blisters occur, it may crack during cold rolling, flaws may occur, or the material of the product thin plate, for example, the uniformity of strength, elongation, etc. may be impaired,
When two plates are generated, breakage of the slab during casting and breakage of the plate during cold rolling in the subsequent process occur, making stable manufacture difficult.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to a continuous casting method for producing aluminum and aluminum alloy slabs without causing local swelling on the slab and without producing two plates. Offering is an issue.

[0005]

According to the present invention, a twin roll type continuous casting machine is used, and a barrel length W (mm) of a casting roll is used.
And diameter D (mm) and pressing pressure F (kgf) between the casting rolls
Is a method for producing aluminum and aluminum alloy slabs by twin roll type continuous casting, characterized in that aluminum or aluminum alloy is cast so as to satisfy the following formula (1).

0.005 ≦ F / W / √D ≦ 1 (1) Table 1 shows the manufacturing conditions of twin roll continuous casting of aluminum and the like by the present inventors and the slabs. It is an example of the property. The presence or absence of local blisters was visually observed on the vertical cross section of the center of the slab in the width direction, and the two plates were based on visual judgment. The melts with numbers 1 to 7 are pure Al (JIS A1100), diameter: 400 mm, body length:
Using a 350 mm casting roll, the casting speed is 40 m /
It is an example of casting in minutes. No. 1 has F / W / √D smaller than that of the present invention, so that local blistering is observed. Number 2
F / W / √D of ˜6 is 0.007 to 1.0, which is within the scope of the present invention, and there is no local blistering or the occurrence of two plates. Number 7
Has a F / W / √D of 1.285, which is larger than that of the present invention and has two plates.

[0007]

[Table 1]

Nos. 8 to 14 in Table 1 indicate that the molten metal contains Mg of 4.5.
% Aluminum alloy (JIS A5182), the casting roll used and the casting speed are the same as those of Nos. 1 to 7. The numbers 9 to 13 have F / W / √D within the scope of the present invention, and no local blistering or two plates occur. But number 8 is F / W
/ √D was smaller than that of the present invention, and local blistering occurred. No. 14 has F / W / √D larger than that of the present invention, and 2
It became a plate.

Nos. 15 to 21 in Table 1 are aluminum alloys (JIS A3004) in which the melt contains 1.5% Mn. The casting rolls used are the same as those in Nos. 1 to 7, but the casting speed is 80 m / Here is an example of a minute. No. 15 has F / W / √D smaller than the range of the present invention, and local blisters are observed.
Nos. 16 to 20 have F / W / √D within the scope of the present invention, and there are no local blisters or two plates. The number 21 had a larger F / W / √D than that of the present invention, and was two plates.

Nos. 22 to 28 in Table 1 are aluminum alloys (JIS A5182) whose molten metal contains 4.5% of Mg, and diameter: 1
Using a casting roll of 200 mm, body length: 800 mm,
In this example, the casting speed is 80 m / min. Number 22 is F / W /
√D is smaller than that of the present invention, and local blisters are observed. The numbers 23 to 27 have F / W / √D within the scope of the present invention,
There are no local blisters or two boards. Number 28 is F / W / √D
Was larger than that of the present invention and was two plates.

In the present invention, the mechanism of local blistering is not clear, but local blistering occurs in any component of aluminum and aluminum alloy, and 1200 mm even when the diameter of the casting roll is 400 mm.
Occurs also when the casting speed is 40 m / min and 80 m / min. But F / W / √D
Has not occurred when 0.005 or more.

Further, the mechanism by which the two plates are generated in the present invention is not necessarily clear, but the two plates can be generated in any component of aluminum and aluminum alloy, and 1200 mm even when the diameter of the casting roll is 400 mm. It also occurs when the casting speed is 40 m / min and 8
It also occurs at 0 m / min. However, F / W / √D is 1
It has not occurred in the following cases. Therefore, in the present invention, F
Casting is performed with / W / √D set to a range of 0.005 or more and 1 or less.

[0013]

According to the present invention, there is no formation of local blisters on the slab and generation of two plates,
A slab of aluminum or the like can be manufactured by twin roll type continuous casting.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an example of twin roll type continuous casting.

[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: cast piece, 7: side dam, 8: direction of rotation of casting roll.

Claims (1)

[Claims] 1. A twin roll type continuous casting machine is used, and the body length W (mm) and diameter D (mm) of the casting rolls and the pressing pressure F (kgf) between the casting rolls satisfy the following equation (1). A method for producing aluminum and aluminum alloy slab by twin roll type continuous casting, which comprises casting aluminum or aluminum alloy in this manner. 0.005 ≦ F / W / √D ≦ 1 ……………… (1)