JPH07276015A - Receiving base for half-continuously casting aluminum square cast ingot and production of square cast ingot - Google Patents

Abstract

PURPOSE:To make possible the smooth performance of an efficiently stable continuous casting work by specifying the length of long side parts of a receiving base and raising the side edges of shot side part higher than the center side edge of the long side part in a specific range. CONSTITUTION:The short side parts 12 are arranged so as to face to both sides of the long side parts 11 in the receiving base 1. The recieving base 1 is fitted to the bottom part of a cooling mold opened the upper and the lower parts. Molten metal poured in the cooling mold, is received by the receiving base 1, and after solidifying the molten metal by cooling from the mold concurrently, this solidified ingot is taken out and cooled by spraying cooling water to the cast ingot having rectangular cross section. The length of the long side part 11 of the receiving base 1 is made to be >=800mm and the side edges of the short side parts 12 are made to be higher than the center side edges of the long side part 11 by the range of 80-300mm. By this method, the leakage of the metal at the continuous casting 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 pedestal for semi-continuous aluminum square ingot casting and a method for manufacturing the square ingot, and a pedestal and a pedestal capable of continuously and accurately casting an aluminum square ingot. It is intended to provide a method for manufacturing an aluminum square ingot used.

[0002]

2. Description of the Related Art Casting an aluminum slab with a rectangular (or rectangular) cross section is convenient for obtaining a desired product by rolling or other processing, and has been conventionally adopted in various ways. That is, this method is generally a continuous casting of a slab having a rectangular cross section by a cooling mold and a pedestal set at the bottom of the cooling mold. It is drawn downward, and water is poured and cooled from the bottom of the mold onto the peripheral surface of the slab on the pedestal for continuous casting.

However, according to such a conventional general method, at the initial stage of casting, a difference in solidification timing in the casting direction of the long side is generated at the bottom of the ingot, and this difference causes so-called butt curl to bend, resulting in a short ingot. A gap is created between the side shell and the water-cooled mold, and the metal flows into the gap to cause metal leakage.

Regarding the above-mentioned butt curl, Japanese Patent Publication No. 6
0-141 gazette is proposed, a butt curl is considerably reduced by forming a convex portion on the long side middle portion of the cradle, and reducing the cooling effect of the long side intermediate portion by the convex portion,
Particularly, a large metal leak can be appropriately prevented, and the leak metal extraction in the casting pit can be significantly reduced.

[0005]

Recently, a wider rectangular ingot for rolling improves the efficiency of casting and rolling, and improves the yield of rolled sheets, which is rapidly developing and spreading. It is needless to say that it is preferable to cast an alloy such as an Al-Fe alloy or an Al-Mn alloy that easily causes metal leakage. That is, since the solidification temperature range is wide in such an alloy that easily causes metal leakage, metal leakage and other troubles are unavoidable in the above-described conventional art.

[0006]

In view of the above-mentioned circumstances, the present invention has been further studied, and in the pedestal set in the cooling mold as described above, the short side portion side edge thereof is the long side portion center. It has succeeded in appropriately preventing the occurrence of an effective metal leakage trouble even under the special alloy composition conditions as described above by increasing the height in a proper range from the side edge, and is as follows. .

It is attached to the bottom of a cooling mold whose top and bottom are open, receives the molten metal poured into the cooling mold, solidifies it by cooling from the mold, and then draws it out and applies cooling water to the ingot with a rectangular horizontal cross section. A pedestal of a rectangular ingot for semi-continuous casting, which is designed to be cooled, wherein the pedestal has a long side portion length of 800 mm or more, and a short side portion side edge is 80 to 300 mm more than a long side portion central side edge. A pedestal for semi-continuous casting of aluminum rectangular ingots, which is characterized by being raised within the range.

The pedestal, which has a rectangular shape in a plane, is divided into a plurality of blocks in a direction intersecting with the side surface of the pedestal, and by selecting one or more combination arrangement relations in the plurality of blocks, The pedestal for semi-continuous casting of the aluminum rectangular ingot, characterized in that the length thereof can be changed.

It has a rectangular shape in a plan view and has a long side length of 80.
A pedestal having a height of 0 mm or more and a side edge of the short side portion thereof being 80 to 300 mm higher than that of the center side edge of the long side portion is attached to the bottom of the cooling mold having the upper and lower sides opened to melt the molten metal. Injecting and starting casting, and controlling the casting speed so that the short side edge of the pedestal is still located in the cooling mold after the butt curl at the bottom of the ingot is almost finished. And a method for manufacturing an aluminum ingot.

[0010]

Operation: The cooling mold is mounted on the bottom of the open upper and lower parts, receives the molten metal poured into the cooling mold, solidifies it by cooling from the mold, and then draws it out and cools the ingot with a rectangular horizontal cross section. A pedestal of a rectangular ingot for semi-continuous casting, which is cooled, wherein a long side length of the pedestal is 800
A slab that is convenient for rolling etc. can be obtained by having a thickness of at least mm, and casting is performed because the short side edge of such a pedestal is raised within the range of 80 to 300 mm more than the long side central side edge. Effectively prevent metal leakage caused by butt curl in the initial stage.

A more preferable range of the side edge of the pedestal short side is 90.
To 200 mm, more preferably 100 to 150 mm, and by adopting a pedestal selected within such a range, it is possible to effectively prevent even small metal leaks caused by butt curl, and have a wide alloy composition. It can be used properly, is easy to handle, and enables stable operation.

It is divided into a plurality of blocks in the direction crossing the side surface of the pedestal which is rectangular in plan view, and the side surface is divided by selecting one or more combination arrangement relations in the plurality of blocks. Since the length can be changed, the length of the long side portion can be appropriately changed, and the pedestal can be shared for the molds having the long side dimension variously changed, thereby effectively exhibiting the action of the present invention. . As for the mold, the long side cooling member should be elastically fixed by interposing the short side cooling member at an arbitrary position between the long side cooling members having a depth of 70 to 100 mm and having an appropriate length. Thus, the same member can be used as a mold having various changes in long side length.

[0013] It has a rectangular shape in plan and has a long side length of 800 mm.
Even if it is more than the above, the pedestal whose side edge at the short side portion is raised within the range of 80 to 300 mm than that at the center side edge of the long side portion is mounted on the bottom of the cooling mold which is open at the top and bottom to inject the molten metal. Then start casting, after the butt curl at the bottom of the ingot is substantially finished, the bat by controlling the casting speed so that the short side edges of the pedestal are still located in the cooling mold. Due to the curl, a gap is created between the side edge of the short pedestal and the ingot shell, and even if the metal flows into it, it solidifies in the pedestal area, and smooth casting can be performed without causing metal leakage.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of the present invention will be described with reference to the accompanying drawings. The pedestal according to the present invention can be embodied as shown in FIGS. 1 and 2 and as shown in FIGS. . That is, in all of these, the short side portions 12 are provided on both sides of the long side portion 11 of the pedestal 1 having the long side portion of 800 mm or more.
While the middle of 1 is formed low, all the short side portions 12 are formed to be considerably higher than the central side edge of the long side portion 11.

In the long side portion 11 as described above, the protruding side walls 13 are formed on both sides thereof, but the middle portion of the protruding side wall 13 is lowered in any case, and the short side portion 1 is formed.
Between the steep inclined side wall portion 14 and the gently inclined side wall portion 15
The side wall portion 1 having a short side portion 12 and a low middle portion
A predetermined height h is set between the two and 3.

The above-mentioned height h becomes apparent when the bat curl has a long side portion length of more than 800 mm,
Since the metal leaks, the long side length of the pedestal 11 is 800
80 mm to 300 mm, preferably 90 mm
˜200 mm, more preferably 100 to 150 mm is as described above, and the above h is 80 based on the results of the field study of many rectangular molds by the present inventors.
If it is less than mm, the short side of the pedestal tends to come off the cooling mold at the time of occurrence of butt curl, and there is a possibility of trouble such as metal leakage. Even if the cradle descending speed is made small, metal leakage can be prevented, but if it is made too slow, it becomes difficult to obtain a sound ingot, and work efficiency is lowered.

The upper limit of the height h is 300 mm,
If the height h is larger than this, the upper edge of the short side part enters into the mold too deeply and engages, hindering the continuous casting operation. Further, the cut-out part of the ingot increases and the yield decreases. Come on.

In the pedestal of the present invention in which the upper edge of the short side portion 12 is raised by the height h as described above, the short side portion of the pedestal is still in the water-cooled mold when the bat curl occurs. Therefore, even if the metal overflows in the gap created by the butt curl in the pedestal, it solidifies by cooling from the pedestal,
No metal leaks from the cradle. No large bat curl occurs after the pedestal leaves the water-cooled mold, so the short shell does not tilt significantly and metal leakage does not occur. This makes it possible to cast a wide ingot without trouble such as metal leakage, regardless of the type of alloy.

As shown in FIG. 1, the height h may be taken mainly by the short side part, but as shown in FIG. 2, the gently slanted side edge part 15 is adopted, and the ingot long side part is obtained. The center of 11 is water-cooled first, and the water-cooling gradually conforms to the general aspect, so that the outer peripheral surface is gradually cooled as compared with the case where the outer peripheral surface is water-cooled at one time, and bat curl can be reduced. .

The cradle according to the present invention may be of a divided type as shown in FIGS. 3 to 5, if necessary, that is, the long side portion is interposed between the intermediate portion body 2 and the short side portion body 3 and between them. Formed by the interposer part 4 and joined to each other, and the interposer part 4 having different thickness is adopted, or the interposer part 4 is omitted as shown in FIG. It is possible to obtain slabs having different side dimensions. As shown in the drawing, it is preferable to employ the steeply inclined side edge portion 14 as shown in FIG. 1 in the case where the belly is connected with the blocks 2 to 4 as described above.

Regarding the casting speed of the present invention,
At the beginning of casting, after the bat curl occurs after the start, the short side portion of the pedestal is controlled so as to pass through the cooling mold. Therefore, the casting speed should be determined in consideration of the difference in height between the short side portion and the long side central portion of the pedestal. Conversely, depending on the alloy, if the initial casting speed is determined, the difference in height between the pedestal short side portion and the long side center edge portion is determined. Generally, the initial casting speed is preferably 35 to 60 mm / min, 35 mm / min.
If it is less than min, the temperature of the molten metal in the mold is too low, and casting cannot be performed. On the other hand, if it is more than 60 mm / min, bat curl becomes remarkable and metal leakage easily occurs.

The present invention can be applied to any case where an aluminum square ingot is obtained irrespective of the type of alloy, but Al is particularly apt to cause metal leakage.
By applying to -Fe alloy or Al-Mn alloy, the effect can be obtained highly.

Some embodiments according to the present invention will be described as follows. Production Example 1 Using a mold having a cross section of 406 × 1250 mm and a pedestal of the present invention in which the short side portion is 100 mm higher than the long side end portion, Al-1.1%
Casting of a square ingot of Fe alloy: casting temperature: 680 ° C., initial casting speed: 40 mm / min, steady state (casting start 4 min or later)
Casting speed: 55 mm / min, initial cooling water amount: 1200
Casting was performed under the casting conditions of liter / min and a cooling water amount of 2000 liter / min at a steady state (casting start 4 min or later). The inclination gradient from the short side portion to the long side edge portion of the pedestal was 70 °. Further, as a comparative example, the same alloy ingot was cast under the same casting conditions using a conventional pedestal in which the heights of the short side portion and the long side portion were not different.

As a result of carrying out as described above, when the pedestal of the present invention was used, an ingot having a length of about 3 m was obtained without any metal leakage. After casting, it was observed that the molten metal had flowed into the gap created between the short side of the ingot and the pedestal by the butt curl, but this molten metal spilled out of the pedestal and remained in the pedestal. There was no outflow of molten metal. On the other hand, when the pedestal of the comparative example is used, about 2
Metal leakage occurred at min, but the leakage soon stopped, and an ingot of about 3 m in length was obtained. When the tip of the ingot was examined after casting, metal leak was observed on the short side surface at a position about 80 mm from the lower end of the ingot.

Production Example 2 Using a mold having a cross section of 508 × 1450 mm and a pedestal in which the short side is 110 mm higher than the long side, a square ingot of Al-1.1% Fe alloy is cast at a temperature of 680. ℃, initial casting speed: 4
Casting at 0 mm / min, casting speed at steady state (casting start 4 min or later): 50 mm / min, initial cooling water amount: 1400 liters / min, steady state (casting start 4 min or later) cooling water amount 2000 liters / min did. The inclination of the pedestal from the short side portion to the long side edge portion was 35 °. Further, as a comparative example, the same alloy ingot was cast under the same casting conditions using a conventional pedestal in which the heights of the short side portion and the long side portion were not different.

That is, when the pedestal of the present invention was used, an ingot having a length of about 3 m was obtained without any metal leakage. After the casting, it was observed that the molten metal had flowed into the gap created between the short side portion of the ingot and the pedestal due to the butt curl after casting, and the amount of this molten metal flowed out was larger than that in the case of Example 1. The molten metal did not flow out of the pedestal. On the other hand, when a pedestal having a protrusion of 60 mm in height and 200 mm in length was used as a comparative example, a significant metal leak occurred from the short side portion about 2 minutes after the start of casting. . Although we stopped the lowering of the pedestal, metal leakage did not stop and we had no choice but to stop casting.

[0027]

According to the present invention as described above, the metal leakage during the continuous casting of this kind is not affected by the kind of the metal by merely adjusting the pedestal, and the relatively small one is effective. Therefore, it is possible to smoothly carry out an efficient and stable continuous casting work under the condition that there are few special difficulties in the operation, so that the invention is industrially effective. is there.

[Brief description of drawings]

FIG. 1 is a side view and a plan view showing an example of a cradle according to the present invention.

FIG. 2 is a side view and a plan view similar to FIG. 1, showing another example of the cradle according to the present invention.

FIG. 3 is a side view of a pedestal showing still another example according to the present invention.

FIG. 4 is a side view showing a disassembled state of the one shown in FIG.

FIG. 5 is a side view of the assembly shown in FIGS. 3 and 4 with the interposition body removed and assembled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cradle 2 Intermediate part body 3 Short side part body 4 Interposition part body 10 Cradle surface 11 Long side surface 12 Short side surface 13 Side edge part 14 Sloping side edge part 15 Slowly sloping side edge part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinjo Seo 1-34-1 Kambara, Kambara-cho, Anbara-gun, Shizuoka Nipparu Giken Co., Ltd.

Claims (3)

[Claims] 1. A cooling mold which is mounted on the bottom of an open upper and lower part, receives the molten metal poured into the cooling mold, solidifies it by cooling from the mold, and then draws it out and injects the cooling water into a rectangular ingot having a rectangular horizontal cross section. A pedestal of a rectangular ingot for semi-continuous casting, which is applied and cooled, wherein the pedestal has a long side portion length of 800 mm or more, and a short side portion side edge is 80 mm or more than a long side portion central side edge. A pedestal for semi-continuous casting of aluminum square ingots, which is characterized by being raised within the range of up to 300 mm. 2. A plurality of blocks are divided in a direction intersecting a side surface of a pedestal which is rectangular in plan view,
2. The aluminum rectangular ingot semi-continuous casting receptacle according to claim 1, wherein the side length can be changed by selecting one or more combined arrangement relations among the plurality of blocks. Stand. 3. A rectangular shape in plan view having a long side length of 800.
mm or more, and the side edge of the short side portion thereof is raised within the range of 80 to 300 mm from the center side edge of the long side portion. Injecting and starting casting, and controlling the casting speed so that the short side edge of the pedestal is still located in the cooling mold after the butt curl at the bottom of the ingot is almost finished. And a method for manufacturing an aluminum ingot.