JPH05245585A - Device for casting deformed cast billet - Google Patents

Abstract

PURPOSE:To produce a cast billet having good surface and no surface crack even in the deformed cast bullet having complicate shape by arranging a cooling device for directly cooling the cast billet with cooling water independently to the cooling in a mold. CONSTITUTION:Piping is connected with connecting members 16, 17 and cooling water is made to flow in the lower step mold 11b and also flowed in cooling piping 15. Thereafter, when the molten metal is poured into a space surrounded in the inner surface 12 of the mold 11, the molten metal is brought into contact with the inner surface 12 of the mold 11 and cooled to form the solidified shell. The cast billet is successively drawn out downward from a mold 11. Then, the cast billet is directly cooled with cooling water by receiving the injection of the cooling water from the coding water piping 15. In the mold 11, the extremely weak cooling is given, and after the cast billet comes out from the mold 11, the intense cooling is given by the cooling water and the cast billet is perfectly solidified. Therefore, it is prevented that cold shut-like ripple caused by solidification of the cast billet in the mold 11 is formed. As the cast billet coming out from the mold 11 is directly and forcedly cooled with the cooling water, the development of the surface crack can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a profile ingot casting apparatus for casting an ingot to be subjected to stencil processing, roll processing, rolling, drawing, extrusion, and other plastic processing in general, including expansion processing. Particularly, the present invention relates to a profile ingot casting apparatus for continuously casting an ingot for wrought processing of aluminum or aluminum alloy, which is suitable for use in forging and the like.

[0002]

2. Description of the Related Art Conventionally, an aluminum or aluminum alloy product is manufactured by subjecting an ingot (for example, a round large-diameter billet) obtained by continuous casting to a predetermined cross-sectional shape by extrusion and then forging. It has been commercialized through plastic working once. However, if the aluminum or aluminum alloy product has a round cross section, the round billet can be forged as it is into a product.

However, the above-mentioned aluminum or aluminum alloy product is usually subjected to plastic working twice unless the product has a round cross section, so that its manufacturing cost is high. Further, when the final shape of the aluminum or aluminum alloy product and the shape of the ingot are remarkably different from each other, when the above-mentioned extrusion process is performed, the crystal grains or the crystallized product of the ingot have directionality in the extrusion direction. Or the surface layer is recrystallized and the crystal grains become coarse. After that, when such an extruded material is forged, there is a drawback that the product is cracked due to the direction of the crystal grains or the mechanical properties thereof are partially deteriorated.

Therefore, by manufacturing a so-called atypical ingot in which the shape of the ingot is as close as possible to the shape of the product and forging this atypical ingot, the extrusion process is omitted and the cost is reduced. It is intended to prevent deterioration of mechanical properties of products.

FIG. 2 is a vertical sectional view showing a conventional continuous casting mold, and FIG. 3 is a sectional view taken along line AA of FIG.
The mold 1 has a casting surface 2 that matches the cross-sectional shape of the atypical ingot to be used as the casting mold. The mold 1 has a cavity 3 therein, and cooling water is allowed to flow through the cavity 3 to cool the mold 1. The lower end portion of the casting surface 2 of the mold 1 has a chamfered shape, and a cooling water ejection hole 4 is provided in this portion. By injecting the cooling water toward the ingot (not shown) from the ejection holes 4, the ingot emerging downward from the mold 1 is directly cooled by the cooling water.

[0006]

However, since the atypical ingot has a complicated cross-sectional shape, if the cooling effect of the cooling water for the continuous casting mold is constant in the outer peripheral direction of the ingot, insufficient cooling will occur. Is locally generated. Therefore, due to insufficient cooling, a perspiration phenomenon occurs in the atypical ingot,
There is a problem that breakout or the like occurs during casting.

Therefore, the inventors of the present application provided a sleeve 5 inside as shown in FIG. 4, and adjust the flow rate of the cooling water in the mold by this sleeve 5, or as shown in FIG.
The inner surface of the inner wall 7 forming the casting surface 2 of the mold 1, that is,
Grooves 6 are provided on the surface in contact with the cooling water to adjust the contact area of the cooling water, or fins 8 are provided on the inner surface as shown in FIG. We have proposed a method of increasing local volume and eliminating local cooling shortage. Further, as shown in FIGS. 7 and 8, a method of adjusting the cooling ability of the cooling water discharged from the lower part of the mold by changing the hole diameter or the arrangement pitch of the cooling water discharge holes 4 has also been proposed (Japanese Patent Application No. 2000-242242). Flat 3-192514).

As a result, the casting surface of the atypical ingot is improved,
An effect that cannot be obtained with the conventional technology is achieved. However, if the shape of the atypical ingot to be cast becomes even more complicated as shown in FIG. 9, the above-mentioned means cannot sufficiently adjust the cooling capacity, so that the occurrence of defects can be completely prevented. You cannot do it.

As shown in FIG. 9, when the shape of the ingot cross section is extremely complicated, the portion 9 indicated by the one-dot chain line in FIG.
The ingot is strongly pressed against the mold due to solidification shrinkage. If the ingot cross-sectional shape does not have a recess as described above, the ingot separates from the mold due to solidification shrinkage, but if the cross-sectional shape has a recess as described above, this recess causes the mold to solidify shrinkage. Pressing, conversely the ingot receives a tensile force from the mold. For this reason, deep ripples (see FIG. 10) in a molten metal boundary form at this portion, and the ingot cannot be used in the forging step as a forging ingot.

In order to avoid this ripple and obtain a good casting surface, solidification shrinkage causes the portion 9 to easily press the mold.
It is necessary to weaken the cooling of. However, if the cooling water in the mold 1 is reduced and the cooling in the mold is weakened, the amount of direct cooling water injected from the lower part of the mold 1 toward the ingot also decreases, and the direct cooling (secondary cooling) also weakens. Will end up. For this reason, surface cracking (see FIG. 10) occurs especially in the case of an aluminum alloy having a high cracking sensitivity such as the 6061 alloy.

The present invention has been made in view of the above problems, and in casting atypical ingots having a complicated shape,
An object of the present invention is to provide an apparatus for manufacturing atypical ingots, which is capable of preventing the occurrence of surface cracks and obtaining ingots having a good casting surface.

[0012]

[MEANS FOR SOLVING THE PROBLEMS] The apparatus for producing an atypical ingot according to the present invention comprises a cylindrical mold having a pouring space corresponding to the cross-sectional shape of the atypical ingot to be a casting mold, and cooling in the mold. After the solidification of at least the peripheral portion, it has a cooling device for cooling the ingot coming out of the mold with cooling water in the lower part of the mold, the cooling ability by the mold and the cooling ability by the cooling water separately. It is characterized by being configured to be adjustable.

[0013]

In the present invention, cooling of the ingot by the mold,
The cooling of the ingot by the cooling device can be adjusted individually. Therefore, the cooling in the mold is weakened to form a thin solidified shell that does not cause breakout in the mold. Therefore, the occurrence of ripples due to the solidification shrinkage of the ingot is avoided. After that, the ingot exits the mold and is directly cooled by spraying cooling water by the cooling device. A stable solidified layer is formed by cooling with this cooling device. This makes it possible to cast atypical ingots in which both ripples and surface cracks are prevented.

In this case, the cooling in the mold may be performed only by the contact of the mold wall, and in addition to the cooling by the contact of the mold wall, as shown in FIG. It may be jetted to cool the ingot.

Further, as shown in FIG. 4 to FIG. 8, the width or thickness of the ingot can be obtained by providing a sleeve, a groove, fins, etc. in the mold, or adjusting the diameter and pitch of the mold cooling water discharge holes. The cooling capacity in the direction may be adjustable.

[0016]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a cooling apparatus for atypical ingots according to an embodiment of the present invention. As an example, the mold 11 is divided into an upper mold 11a and a lower mold 11b, and the molten metal is cast into a region surrounded by an inner surface (casting surface) 12 thereof. The mold 11 is formed of a material having excellent thermal conductivity such as copper, the upper mold 11a is solid, and the lower mold 11b is hollow. Then, the lower mold 11b
Cooling water flows through the interior 18 of the mold to cool the mold 11b. A connection member 16 is attached to the mold 11b, and a pipe (not shown) connected to a water supply source such as a water pump is connected to the connection member 16 and cooled in the mold 11b via the connection member 16. Water is supplied. A mold cooling water discharge hole 14 is provided below the inner surface 12 of the mold 11b. Also, the inside 18 of the mold 11b
A sleeve 13 for adjusting the cooling ability of the mold with the mold cooling water in the mold circumferential direction is installed in the.

On the lower surface of the mold 11b, a cooling water pipe 15 made of a copper pipe or the like is arranged so as to extend along the inner edge of the mold 11b, that is, located near the inner surface 12 of the mold 11b. There is. A connection member 17 is attached to the cooling water pipe 15, and a pipe (not shown) connected to a water supply source such as a water pump is connected to the connection member 17.
Cooling water is supplied into the cooling water pipe 15 via the connecting member 17. Further, the cooling water pipe 15 is provided with a large number of discharge holes in order to eject the cooling water toward the mold inside thereof.

Next, the operation of the apparatus for manufacturing atypical ingots constructed as described above will be described. Pipes are connected to the connecting members 16 and 17 to allow cooling water to flow in the lower mold 11b and to allow cooling water to flow in the cooling pipe 15. Then, the molten metal is poured into the space surrounded by the inner surface 12 of the mold 11. Then, the molten metal comes into contact with the inner surface 12 of the mold 11 and is cooled, and a solidified shell is formed. In this case, mold 1
The flow rate of the cooling water in 1b is set to be a weak cooling sufficient to form a solidified shell having a thickness that does not cause breakout.

The ingot then emerges below the mold 11 and is withdrawn. Then, the cooling water is jetted from the cooling water pipe 15 and directly cooled by the cooling water. Assuming that the injection amount of this cooling water is sufficiently large, the ingot emerging from the mold 11 is strongly cooled. As a result, the ingot is completely solidified.

In this embodiment, extremely weak cooling is applied in the mold 11, and after the ingot leaves the mold 11, strong cooling by cooling water is applied to complete solidification, so that the ingot is condensed in the mold. This prevents formation of ripples in the shape of a molten metal. Thereby, a good casting surface can be obtained. Also,
Since the ingot that has left the mold 11 is directly cooled by the cooling water and strongly cooled, surface cracks are prevented from occurring.

[0022]

According to the present invention, a cooling device for directly cooling the ingot with cooling water is provided independently of the cooling in the mold, so that there is no ripple even in atypical ingots of complicated shape. It is possible to manufacture an ingot having a smooth casting surface and preventing surface cracking.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an apparatus for manufacturing atypical castings according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional mold for atypical ingots.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view showing a sleeve provided in a mold.

FIG. 5 is a partially cutaway perspective view showing a groove provided in a mold.

FIG. 6 is a cross-sectional view showing fins provided in a mold.

FIG. 7 is a schematic view showing discharge holes of cooling water in a mold.

FIG. 8 is a schematic view showing discharge holes of cooling water in a mold.

FIG. 9 is a schematic diagram showing an example of a cross section of a modified ingot.

FIG. 10 is a schematic perspective view showing surface defects of 6061 alloy.

[Explanation of symbols]

 1, 11, 11a, 11b; Mold 2; Casting surface 12; Inner surface 4, 14; Mold cooling water ejection hole 15; Cooling water pipe

Claims (1)

[Claims] 1. A cylindrical mold having a casting space corresponding to the cross-sectional shape of a modified ingot to be cast, and a ingot that has been cooled in the mold and solidified at least in the peripheral portion thereof, and then has come out of the mold And a cooling device for cooling with a cooling water in the lower part of the mold, wherein the cooling capacity by the mold and the cooling capacity by the cooling water can be individually adjusted.