JP3959847B2 - Continuous casting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous casting apparatus that casts an ingot of metal such as copper or copper alloy, and more particularly to a continuous casting apparatus that improves problems such as ingot defects caused by flux or soot and deterioration of working environment. .
[0002]
[Prior art]
FIG. 3 is a cross-sectional view showing an example of a conventional continuous casting apparatus. The continuous casting apparatus includes a tundish 21 for temporarily storing a molten metal 24 supplied from a melting furnace (not shown), a nozzle 22 extending downward from the bottom of the tundish 21, and a molten metal poured from the nozzle 22. 25 is cooled and solidified, and a mold 23 for forming an ingot 26 from the molten metal 25, a mold cradle 27 for supporting the mold 23, a vibration adjacent to the mold cradle 27, and vibrating to the mold 23 via the mold cradle 27 And a vibration device (not shown) connected to the vibration plate 28.
[0003]
When the ingot 26 is continuously cast using such a continuous casting apparatus, casting is performed by covering the molten metal surface 29 in the mold 23 with a coating material such as flux or soot. The flux or soot is used for the purpose of preventing the molten metal surface 29 from being oxidized by the outside air, and for lubrication and mold release between the ingot 26 and the mold 23.
[0004]
However, when flux or soot is used, ingot defects caused by the flux or soot occur, such as entanglement of the flux or soot in the surface or inside of the ingot 26, or oxidation or blowhole due to flux or soot breakage. There is a drawback that it is easy. In addition, there are problems such as significant deterioration of working environment due to dust of flux or soot, and contamination of mold cooling water by flux or soot. Furthermore, heat conduction is hindered by the presence of flux or soot between the mold 23 and the ingot 26, and it takes time to cool the ingot 26, so that it is difficult to increase the casting speed. .
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a continuous casting apparatus that can reduce ingot defects, improve the working environment and contamination of mold cooling water, and increase the casting speed.
[0006]
[Means for Solving the Problems]
Such a problem is as a continuous casting device,
A tundish that temporarily stores the molten metal supplied from the melting furnace, a nozzle that extends downward from the bottom of the tundish, a mold that cools and solidifies the molten metal poured from the nozzle, and forms an ingot from the molten metal, Between the tundish and the mold, a cover that shields the molten metal inside the mold from the outside air and can enclose a reducing gas or an inert gas,
The cover consists of a cover lid provided at the bottom of the tundish and a cover bottom provided at the top of the mold,
The cover lid portion is provided so as to surround the nozzle and the upper part of the mold and open downward.
The opening end of the cover lid is detachably fitted to a seal box formed on the outer edge of the cover bottom,
The aforementioned seal box, seal material comprising one or more selected from powder material and granules quality or Ranaru group is injected,
The clearance between the open end and the seal box is solved by using the one sealed with the sealing material.
Moreover, you may use what the inner wall of the said mold consists of graphite.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
1 and 2 are views showing an example of the continuous casting apparatus of the present invention. The casting apparatus includes a tundish 1 for storing molten metal 4, a nozzle 2 for flowing out the molten metal 4, and a mold 3 for forming an ingot 6. Between the tundish 1 and the mold 3, the interior of the mold 3 is provided. A cover 7 for shielding the molten metal 5 from the outside air is provided.
[0008]
The tundish 1 is a liquid storage container for temporarily storing molten metal 4 supplied from a melting furnace (not shown), and the inside thereof is in a reducing gas or inert gas atmosphere state.
A nozzle 2 for pouring the stored molten metal 4 into the mold 3 is provided at the bottom of the tundish 1, and its tip is immersed in the molten metal 5 inside the mold 3. Yes.
[0009]
The mold 3 cools and solidifies the molten metal 5 poured from the nozzle 2, and forms an ingot 6 from the molten metal 5. An upper opening for pouring the molten metal 5 is provided at the top, and at the bottom. A bottom opening for withdrawing the ingot 6 is provided.
The mold 3 includes an inner wall 3a and an outer wall 3b that supports the inner wall 3a, and a cooling water channel (not shown) that supplies cooling water to the mold 3 is disposed on the inner wall 3a and the outer wall 3b. Yes.
[0010]
A mold cradle 14 that supports the mold 3 is provided on the outer periphery of the mold 3 in a direction perpendicular to the side surface of the mold 3, and a vibration adjacent to the mold cradle 14 is provided outside the mold 3. A plate 15 and a vibration device (not shown) connected to the diaphragm 15 are provided. The vibration plate 15 is provided to apply vertical minute vibrations to the mold 3 via the mold cradle 14 in order to smoothly lower the ingot 6 in the mold 3.
[0011]
A cover lid portion 8 of a cover 7 is provided at the bottom of the tundish 1 so as to surround the periphery of the nozzle 2 and the upper portion of the mold 3 and open downward. A cover bottom 9 of the cover 7 is provided so as to close the opening of the cover lid 8. A flange-like seal box 12 is formed on the outer edge of the cover bottom 9 so that the open end 11 of the cover lid 8 is detachably fitted.
[0012]
A gap is provided between the opening end portion 11 of the cover lid portion 8 and the seal box 12 of the cover bottom portion 9 so that the opening end portion 11 and the seal box 12 do not adhere to each other. This gap is for preventing vibration applied to the mold 3 from the diaphragm 15 from being transmitted to the tundish 1.
[0013]
A sealing material 13 is injected into the seal box 12. The sealing material 13 seals the gap between the opening end portion 11 of the cover lid portion 8 and the seal box 12 of the cover bottom portion 9, and even if vibration is applied to the mold 3, the inside of the cover 10 of the cover 7 is covered. The airtightness of the is maintained.
As the sealing material 13, one or more selected from the group consisting of a powder substance, a granular substance, and a liquid substance can be used. As such a sealing material 13, what was excellent in heat resistance is preferable, for example, sand, oil, etc. are mentioned. These may be used alone or in combination as required.
[0014]
The cover lid 8 has a cast monitoring window 17 made of heat-resistant glass for monitoring the state of the molten metal surface 16 inside the mold 3, and a gas supply pipe 18 that supplies a reducing gas or an inert gas to the cover interior 10. Is provided.
When reducing gas or inert gas is supplied from the gas supply pipe 18 to the cover interior 10, the cover interior 10 is brought into a reducing gas or inert gas atmosphere. Oxidation on the molten metal surface 16 can be prevented.
As the reducing gas or the inert gas, carbon monoxide, nitrogen, argon, or the like which does not affect the molten metal 5 by reacting with the molten metal 5 is used alone or in combination, and the metal to be cast is used. It is possible to select the gas composition according to the properties.
[0015]
The material of the inner wall 3a of the mold 3 is not particularly limited. For example, conventional copper, copper alloy, graphite, or a combination of two or more of these can be used. Among these, graphite is preferably used in terms of lubricity with the ingot 6 and releasability. Moreover, since graphite has good thermal conductivity, the ingot 6 can be efficiently cooled.
[0016]
Next, the process of continuously casting the ingot 6 with the continuous casting apparatus of the present invention will be described.
The molten metal 4 supplied from the melting furnace and stored in the tundish 1 passes through the nozzle 2 and is poured into the mold 3.
[0017]
Here, the inside of the tundish 1 is in a reducing gas or inert gas atmosphere, and the tip of the nozzle 2 is immersed in the molten metal 5 in the mold 3. In the meantime, it is not oxidized while reaching the mold 3.
Furthermore, since the reducing gas or the inert gas is sealed in the cover interior 10 and shielded from the outside air, the molten metal 5 in the mold 3 is also oxidized until it is cooled to become the ingot 6. Never happen.
[0018]
The molten metal 5 poured into the mold 3 is cooled and solidified while descending the inside of the mold 3, which is constantly cooled with cooling water, and becomes an ingot 6. The formed ingot 6 is continuously drawn out from the bottom opening of the mold 3 and then automatically cut to a desired length.
[0019]
In such a continuous casting apparatus, a cover 7 in which a reducing gas or an inert gas that suppresses oxidation of the molten metal 5 is enclosed is provided between the tundish 1 and the mold 3, A gap between the cover lid portion 8 and the cover bottom portion 9 of the cover 7 is sealed with a sealing material 13. Therefore, the inside of the cover 7 is always kept airtight even when vibration is applied to the mold 3, and it is not necessary to use flux or soot for the purpose of preventing oxidation of the molten metal 5. Ingot defects can be prevented.
Further, when the inner wall 3a of the mold 3 is formed of graphite, the graphite is excellent in lubricity and release properties with the ingot 6, so that the flux is used for lubrication and release between the mold 3 and the ingot 6. Or the need to use soot is further eliminated.
[0020]
In such a continuous casting apparatus, since no flux or soot is used, these dusts are not scattered, the working environment is improved, and the cooling water used for cooling the mold 3 is contaminated. As a result, the cost of wastewater treatment costs is reduced.
Furthermore, there is no flux or soot that hinders heat conduction between the inner wall 3a of the mold 3 and the ingot 6, and the heat conductivity is good, so the ingot 6 can be cooled efficiently and the casting speed is improved. Can be made. When a graphite mold is used for the inner wall 3a, the ingot 6 can be cooled more efficiently, and the casting speed can be further improved.
[0021]
【Example】
Examples are shown below.
(Example)
Using the continuous casting apparatus having the above configuration, graphite is used for the inner wall of the mold, carbon monoxide is used as the reducing gas or inert gas sealed in the cover, the casting speed is 210 mm / min, and the molten metal temperature in the tundish Copper was continuously cast under casting conditions of 1140 ° C. and cooling water of 1600 l / min.
As a result of investigating the number of ingot defects in all cast ingots after completion of continuous casting, the rate of occurrence of ingot defects was 0%.
[0022]
(Comparative example)
For comparison, a conventional continuous casting apparatus is used, soot is used as a coating material, continuous casting of copper under a casting speed of 180 mm / min, a melt temperature of 1140 ° C. in a tundish, and cooling water of 1600 l / min. Went.
As a result of investigating the number of ingot defects in all cast ingots after completion of continuous casting, the rate of occurrence of ingot defects was 5%.
[0023]
From these results, it can be seen that when the continuous casting apparatus of the present invention is used, ingot defects can be reduced and the casting speed is improved as compared with the conventional case.
In addition, since no soot is used, the working environment is greatly improved, and the cooling water is less contaminated than in the conventional case.
[0024]
【The invention's effect】
As described above, in the continuous casting apparatus of the present invention, instead of using a flux or soot, a cover enclosing a reducing gas or an inert gas is provided between the tundish and the mold, and further, Since the gap between the cover lid and the bottom of the cover is sealed with a sealing material, it has excellent effects of reducing ingot defects, improving work environment and mold cooling water contamination, and increasing casting speed Can do.
Moreover, these effects can be further improved by forming the inner wall of the mold from graphite.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing an example of a continuous casting apparatus of the present invention.
FIG. 2 is a view showing an example of a main part of the continuous casting apparatus of the present invention.
FIG. 3 is a cross-sectional view of an essential part showing an example of a conventional continuous casting apparatus.
[Explanation of symbols]
1 Tundish 2 Nozzle 3 Mold 3a Inner Wall 4 Molten Metal (Tundish)
5 Molten metal (in mold)
6 Ingot 7 Cover 8 Cover lid 9 Cover bottom 11 Open end 12 Seal box 13 Sealing material

Claims (2)

A tundish that temporarily stores the molten metal supplied from the melting furnace, a nozzle that extends downward from the bottom of the tundish, a mold that cools and solidifies the molten metal poured from the nozzle, and forms an ingot from the molten metal, Between the tundish and the mold, a continuous casting apparatus provided with a cover that shields the molten metal inside the mold from the outside air and can contain reducing gas or inert gas,
The cover consists of a cover lid provided at the bottom of the tundish and a cover bottom provided at the top of the mold,
The cover lid portion is provided so as to surround the nozzle and the upper part of the mold and open downward.
The opening end of the cover lid is detachably fitted to a seal box formed on the outer edge of the cover bottom,
The aforementioned seal box, seal material comprising one or more selected from powder material and granules quality or Ranaru group is injected,
A continuous casting apparatus, wherein a gap between the opening end and the seal box is sealed with the sealing material.   The continuous casting apparatus according to claim 1, wherein the inner wall of the mold is made of graphite.

Images