JPH09314286A - Injection pipe for under-poured steel ingot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the melt-sticking of a steel to a charge tube casting even if the charge tube cracks by forming a charge tube brick into double layer tube and arranging a gap between the charge tube brick and the charge tube casting. SOLUTION: In the charge tube 1 for bottom charging steel, ingot, the charge tube brick 3 is formed into double layer tub of an outside tube 3a an the inside tube 3b. The outside tube 3a is fired refractory-made and consists essentially of Al2 O3 -SiO2 , etc., and the inside tube 3b is unfired refractory-made consists essentially of MgO, etc. Further, suitable spacers 7 are inserted between the charge tube casting 2 and the double layer tube 3 to provide a gap 6 of about 3-25mm. By this method, even if the charge tube brick 3 cracks and molten steel is leaked, this steel is not melt-stuck to the charge tube casting 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injecting pipe for a bottom pouring steel ingot, and more particularly to an injecting pipe brick used for casting an ingot, and an injecting pipe for an underpouring steel ingot which is made of an injection pipe casting.

[0002]

2. Description of the Related Art Conventionally, an injection pipe for downward pouring (hereinafter referred to as "injection pipe") used for casting an ingot or the like has a plurality of cylindrical injection pipes in an iron pipe 4 as shown in FIG. Pipe bricks 3 are stacked and put, and sand 5 is put between the iron pipe 4 and the injection pipe brick 3 to fix the bricks.
Was put in the casting pipe casting 2 and sand 5 was put between the iron pipe 4 and the casting pipe casting 2 used. Since this injection pipe 1 is broken when the injection pipe brick 3 is cast,
The molten steel leaking from the cracks and joints is prevented by the layer of sand 5. Further, as shown in FIG. 4, a paper pipe 10 is inserted between the iron pipe 4 and the injection pipe brick 3 and put into the injection pipe casting 2, and the space between the iron pipe 4 and the injection pipe casting 2 is inserted. It is known that sand 5 is put in and fixed. The injection pipe 1 is configured such that the molten metal leaked from the cracks of the injection pipe brick 3 is blocked by the paper pipe 10.

However, in the conventional injection pipe using sand, since the injection pipe brick 3 is broken, it is indispensable to use sand, and since sand is used, the sand is scattered at the time of manufacturing and dismantling the injection pipe. However, there is a drawback that the working environment is deteriorated. In addition, although the paper pipe 10 is used, there is no problem in the setting of the injection pipe and the state of the cast ingot, but since the injection pipe brick 3 is broken during casting, the paper pipe 10
However, there is a drawback in that the metal burns to generate flames and smoke, the molten metal flows out from the joints and cracks of the injection pipe, the metal is welded to the iron pipe, and the metal cannot be removed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an injection pipe in which the injection pipe brick is cracked and the metal leaks out, and this is not welded to the injection pipe casting or the like.

[0005]

In order to achieve the above object, the injection pipe of the present invention has a double-layered injection pipe brick. In addition, the injection pipe of the present invention includes an injection pipe brick 2
It is a layered tube and is installed with a gap between the two-layer tube and the casting for casting. Further, in the above-mentioned injection pipe of the present invention, the outer pipe of the two-layer pipe is made of fire-resistant material,
The inner tube is made of non-fired refractory.

The refractory tube outside the two-layer tube of the present invention is
A product produced by firing and having excellent thermal shock resistance is preferable, but a product similar to a conventional product may be used. In addition, the non-fired refractory tube inside the two-layer tube of the present invention is preferably a castable refractory tube having excellent thermal shock resistance.
The specific material is that the outer tube is Al ₂ O ₃ -SiO ₂ ,
Al ₂ O ₃ or the like is the main component, and the inner tube is MgO, Al ₂ O ₃ —SiO ₂ or the like as the main component. The gap between the injection pipe casting and the two-layer pipe made of refractory brick can be formed by inserting an appropriate spacer between the two-layer pipe and the injection pipe casting. This gap is preferably 3 to 25 mm.

[0007]

According to the present invention, the inner tube of the two-layer tube of refractory brick is made of unfired castable refractory, so that the entire tube can be made of refractory. Also, by using a two-layer pipe, even if the inner pipe is cracked due to thermal shock, the outer pipe is not subject to thermal shock as much as the inner pipe,
It won't break. Further, the inner tube is made of a non-fired castable refractory material, which has excellent thermal shock resistance. Furthermore, in the present invention, since a gap is provided between the two-layer pipe of the refractory and the casting pipe casting, the two-layer pipe is less likely to be cooled by the casting pipe casting, and the two-layer pipe, especially the outer pipe. There is little temperature difference between the inside and outside, and cracking due to the difference in thermal expansion is reduced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. Using a refractory material having the composition shown in Table 1 below, the shape shown in FIG. 1 and FIG.
The outer tube 3a of the two-layer tube having a size of 0 mm, an inner diameter of 125 mm and a length of 320 mm was manufactured by firing using a usual method. Inside the outer pipe 3a, a castable refractory material having the composition shown in Table 1 below was used, with an outer diameter of 125 mm and an inner diameter of 8 mm.
An unfired inner tube 3b having a length of 5 mm and a length of 320 mm was integrally molded.

[0009]

[Table 1]

An inner diameter 200 in which the two-layer pipes 3a, 3b are fixed on the injection pipe holding metal 11 installed on the surface plate mass brick 12
mm, height 2150 mm, injection pipe casting 2 has a thickness of 15
Six pieces were stacked through the mm spacer 7 and the lower part was fixed with mortar 10. A funnel brick 8 is fixed on the two-layer pipe via a spacer 7, and the injection pipe 1 having the shape shown in FIG.
Was manufactured.

Using this injection pipe 1, a molten metal of 1500 ° C. special steel was injected to cast a 7t ingot. After cooling, the two-layer pipe of the injection pipe brick was taken out, and no crack was generated on the outer surface of the two-layer pipe. So 2
When the surface of the inner tube 3b was observed by peeling off the outer tube 3a of the layered tube, vertical cracks were generated in some places,
No molten steel was placed in the cracks.

The two-layer pipe of the above embodiment can be used instead of the injection pipe brick 3 of the conventional injection pipe using sand.

[0013]

EFFECTS OF THE INVENTION The present invention having the above-mentioned structure has the following excellent effects. (1) Injecting pipe The outer pipe 3a of the two-layer pipes 3a and 3b that becomes the brick 3
Since it does not crack, there is no need to use sand, which improves the working environment for casting. (2) Since the outer pipes of the two-layer pipes 3a and 3b are not broken, the molten metal does not leak to the outside of the two-layer pipe,
The metal will not be welded to the injection pipe casting 2 and the metal will not come off. (3) Since there is a gap between the two-layer pipes 3a and 3b and the casting pipe casting 2, the two-layer pipe after casting and the metal in the two-layer pipe can be easily taken out from the casting pipe casting 2.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection pipe according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a cross-sectional view of a conventional injection pipe.

FIG. 4 is a sectional view of another example of a conventional injection pipe.

[Brief description of reference numerals]

 1 injection pipe 2 injection pipe casting 3 injection pipe brick 3a outer pipe of 2 layer pipe 3b inner pipe of 2 layer pipe 4 iron pipe 5 sand 6 gap 7 spacer 8 funnel brick 9 paper pipe 10 mortar 11 injection pipe retainer 12 Surface plate brick

Claims (3)

[Claims] 1. A two-layer pipe (3a, 3b) made of an injection pipe brick (3).
An injecting tube for a bottom pouring steel ingot, characterized by being 2. An injection pipe brick (3) is a two-layer pipe (3a, 3b).
And a gap (6) is provided between the injection pipe brick (3) and the injection pipe casting (2). 3. The outer pipe (3a) of the two-layer pipe (3a, 3b) is made of fired refractory, and the inner pipe (3b) is made of unfired refractory. Claim 1 characterized by the above-mentioned.
Or the injection pipe for the bottom pouring steel ingot of Claim 2.