JPH084884B2 - Sliding nozzle for molten metal container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding nozzle for a molten metal container, and more particularly to a melting nozzle which is excellent in sealing property and in which a sliding plate slides smoothly and melting damage of a lower nozzle due to drift is prevented. The present invention relates to a sliding nozzle for a metal container.

[0002]

2. Description of the Related Art For example, continuous casting of molten steel is performed as follows. That is, the molten steel received from the ladle into the tundish passes through a sliding nozzle attached to the bottom wall of the tundish and an immersion nozzle vertically attached to the lower end of this sliding nozzle, and is placed below the immersion nozzle. Injected into the mold,
A slab is formed and the slab thus formed is continuously withdrawn from the mold as a single long slab.

A conventional sliding nozzle for a molten metal (hereinafter, molten steel will be described as an example) container will be described with reference to the drawings. FIG. 4 is a cross-sectional view showing a conventional sliding nozzle A attached to the bottom wall of a tundish. As shown in FIG. 4, a conventional sliding nozzle A includes a refractory upper nozzle 1, a refractory upper fixing plate 2, a refractory lower fixing plate 3, a refractory sliding plate 4, and a sliding plate 4. Drive means 5 and a refractory collector nozzle 6.

The upper nozzle 1 having an inner hole 1A is vertically inserted into an opening 9A of a nozzle receiving brick 9 provided on a bottom wall 8 of a tundish 7 for a molten steel container.

An upper fixing plate 2 having a through hole 2A is horizontally fixed to the lower end of the upper nozzle 1. Upper fixing plate 2
The through hole 2A and the inner hole 1A of the upper nozzle 1 are aligned with each other.

A lower fixing plate 3 having a through hole 3A is fixed horizontally to the upper fixing plate 2 with a gap. The through hole 3A of the lower fixed plate 3 and the through hole 2A of the upper fixed plate 2 are aligned with each other. The lower fixing plate 3 is made of a high Al ₂ O ₃ refractory having a C content of 10% or less, which is unlikely to cause cracks, surface roughening, or the like.

The sliding plate 4 having the through hole 4A is provided between the upper fixed plate 2 and the lower fixed plate 3. Sliding plate 4
Can be horizontally reciprocated along the lower surface of the upper fixed plate 2 and the upper surface of the lower fixed plate 3 by the driving means 5 such as a cylinder. By sliding the sliding plate 4, the opening degree of the through hole 2A of the upper fixed plate 2 is adjusted, and thus the flow rate of the molten steel flowing out from the tundish 7 is controlled.

The collector nozzle 6 having the inner hole 6A is
It is fixed vertically to the lower surface of the lower fixing plate 3. The inner hole 6A of the collector nozzle 6 and the through hole 3A of the lower fixing plate 3 are aligned with each other. The collector nozzle 6 has a function of rectifying the flow of molten steel whose flow rate is controlled by adjusting the opening of the through hole 2A of the upper fixed plate 2. Therefore, the collector nozzle 6 easily melts due to the uneven flow of the molten steel, and thus has excellent melting resistance and spalling resistance.
It is made of Al ₂ O ₃ —SiO ₂ —C refractory.

The immersion nozzle 10 having a through hole 10A, which is joined to the sliding nozzle A described above, is vertically fixed to the lower end of the collector nozzle 6. Through hole 10A of immersion nozzle 10 and inner hole 6A of collector nozzle 6
Are consistent with each other. Since the immersion nozzle 10 is in direct contact with molten steel, it has excellent corrosion resistance to molten steel A
It is made of the 1 ₂ O ₃ -C refractory.

The above-mentioned conventional sliding nozzle A
According to the above, the driving means 5 is operated to slide the sliding plate 4 in the horizontal direction along the lower surface of the upper fixed plate 2 and the upper surface of the lower fixed plate 3 as shown in FIG. By adjusting the opening of the through hole 2A of the upper fixing plate 2, it is possible to control the flow rate of the molten steel injected from the tundish 7 through the sliding nozzle A and the immersion nozzle 10 into the mold (not shown). it can.

The molten steel whose flow rate is controlled by adjusting the opening degree of the through hole 2A of the upper fixing plate 2 is rectified by passing through the collector nozzle 6, and then the molten steel is passed through the immersion nozzle 10 to generate air. Is injected into the mold without being oxidized and scattered by the entrainment of.

The lower fixing plate 3, the collector nozzle 6 and the immersion nozzle 10 are fixed to each other by a fixing means via a sealing mortar. As the fixing means, bolt tightening, cotter, bayonet, clamp method or the like is adopted.

[0013]

However, the above-mentioned conventional sliding nozzle A has the following problems.

Whichever fixing means is adopted,
Lower fixing plate 3, collector nozzle 6 and immersion nozzle 1
Since the mortar is present in the joint portion of 0, shrinkage of the mortar progresses at the time of pouring molten steel, and the plasticity of the mortar decreases, resulting in poor sealability of the joint portion.

Since all the fixing means use the fixing jig made of iron, when the fixing jig is heated to a high temperature, the fixing jig expands and the fixing function deteriorates. Will have poor sealing performance.

Since the collector nozzle 6 and the dipping nozzle 10 are made of different materials, the collector nozzle 6 and the dipping nozzle 1 are especially affected when the sealing property of the joint becomes poor.
The joint with 0 may locally melt, and in the worst case, molten steel may leak to the outside.

Therefore, an object of the present invention is to obtain excellent sealing properties by reducing the number of joints, and moreover, the sliding plate slides smoothly and the lower nozzle is prevented from melting damage due to uneven flow. To provide a sliding nozzle for a molten metal container.

[0018]

DISCLOSURE OF THE INVENTION The present invention is directed to an upper nozzle made of a refractory material which is vertically attached to a bottom wall of a molten metal container, and a refractory material having a through hole which is horizontally fixed to a lower end of the upper nozzle. A fixed plate made of refractory, a lower nozzle made of a refractory material which is fixed vertically with a distance from the fixed plate, and a through hole capable of horizontally reciprocating along the lower surface of the fixed plate and the upper surface of the lower nozzle. A slide plate made of refractory material, and a drive means for horizontally reciprocating the slide plate along the lower surface of the fixed plate and the upper surface of the lower nozzle, and at the upper end portion of the inner hole of the lower nozzle. Is fitted with a ring made of refractory material consisting of an upper sliding ring and a lower flow straightening ring, and the lower portion of the lower nozzle is immersed in the molten metal injected into the mold from the lower nozzle. Having A.

Another feature of the present invention is that, in the upper sliding ring, a high Al ₂ O ₃ refractory having a C content of 10% or less, which is less likely to cause cracks and surface roughness, and the refractory, , M
The lower rectifying ring is made of any one of refractory materials to which at least one of gO, ZrO ₂ , and SiC is added, and the lower rectifying ring is made of Al ₂ O ₃ -S excellent in melting resistance and spalling resistance.
In addition to the iO ₂ -C refractory material and the refractory material, M
It consists of any one of refractory materials to which at least one of gO, ZrO ₂ , and SiC is added.

Yet another feature of the present invention is that the upper sliding ring and the lower flow straightening ring are integrally formed.

Next, an embodiment of a sliding nozzle for a molten metal container according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a sliding nozzle for a molten metal container according to the present invention, which is attached to a tundish.

As shown in FIG. 1, a sliding nozzle B for a molten metal (hereinafter, molten steel will be described as an example) container of the present invention comprises a refractory upper nozzle 11, a refractory fixed plate 12, and a refractory. It is composed of a lower material nozzle 13, a refractory sliding plate 14, and a driving means 15 for the sliding plate 14.

The upper nozzle 11 having the inner hole 11A is vertically inserted into the opening 18A of the nozzle receiving brick 18 provided on the bottom wall 17 of the tundish 16 for the molten steel container.

The fixing plate 12 having the through hole 12A is horizontally fixed to the lower end of the upper nozzle 11. Fixed plate 12
The through hole 12A and the inner hole 11A of the upper nozzle 11 are aligned with each other.

Lower nozzle 1 made of refractory material having an inner hole 13A
3 is fixed vertically to the fixing plate 12 with a gap. The lower nozzle 13 is formed by integrating the lower fixing plate 3, the collector nozzle 6 and the immersion nozzle 10 in the conventional sliding nozzle A shown in FIG. As shown in FIG. 3, the lower nozzle 13 has a ring 19 made of a refractory material, which is composed of an upper sliding ring 19A and a lower flow straightening ring 19B, which are separately formed in advance, fitted in the upper end portion of the inner hole 13A. It consists of The inner hole 13A of the lower nozzle 13 and the through hole 12A of the fixed plate 12 are aligned with each other. The lower part of the lower nozzle 13 is immersed in the molten steel injected from the lower nozzle 13 into a mold (not shown).

The upper sliding ring 19A is made of a high Al ₂ O ₃ refractory having a C content of 10% or less, which is unlikely to cause cracks or surface roughness. In addition to these refractories,
_MgO, ZrO _{2, SiC,} may be added to the SiO ₂ or the like. The lower flow straightening ring 19B is made of an Al ₂ O ₃ —SiO ₂ —C refractory material having excellent melting resistance and spalling resistance. In addition to this refractory, Mg
_O, it may be added to the ZrO 2, SiC or the like. The lower nozzle 13 is made of an Al ₂ O ₃ -C refractory having excellent corrosion resistance against molten steel.

The sliding plate 14 having the through hole 14A is provided between the fixed plate 12 and the lower nozzle 13. The sliding plate 14 can be horizontally reciprocated along a lower surface of the fixed plate 12 and an upper surface of the lower nozzle 13 by a driving unit 15 including a cylinder. By sliding the sliding plate 14, the opening of the through hole 12A of the fixed plate 12 is adjusted, and thus the flow rate of the molten steel flowing out from the tundish 7 is controlled.

According to the sliding nozzle B of the present invention described above, the driving means 15 is operated to move the sliding plate 14 along the lower surface of the fixed plate 12 and the upper surface of the lower nozzle 13 as shown in FIG. Slide horizontally, and
By adjusting the opening of the through hole 12A of the fixed plate 12, the flow rate of the molten steel injected from the tundish 16 through the sliding nozzle B into the mold can be controlled.

The molten steel whose flow rate is controlled by adjusting the opening of the through hole 12A of the fixed plate 12 is
By passing through it, it is injected into the mold without being oxidized and scattered by entrainment of air.

According to the sliding nozzle B of the present invention described above, since the lower nozzle 13 is integrally formed, the number of joints is significantly smaller than that of the conventional sliding nozzle A shown in FIG. Therefore, excellent sealability can be obtained. Moreover, the upper sliding ring 19A
Thus, the sliding plate 14 slides smoothly, and the lower flow straightening ring 19B prevents melting damage of the lower nozzle 13 due to uneven flow of molten steel.

Upper sliding ring 19A and lower straightening ring 1
9B may be integrally molded.

[0033]

Next, the present invention will be described in more detail with reference to Examples.

Using the sliding nozzle of the present invention as shown in FIG. 3, A1 killed steel was cast under the casting conditions as shown in Table 1. The characteristics of the refractory material of each part of the sliding nozzle of the present invention used at this time are as shown in Table 2.

Next, using a conventional sliding nozzle as shown in FIG. 4, under the same casting conditions as in Table 1, A
1 Killed steel was cast. The upper fixing plate in the conventional sliding nozzle had the same characteristics as the upper sliding ring in Table 2, the collector nozzle had the same characteristics as the lower flow straightening nozzle in Table 2, and the immersion nozzle had the same characteristics as the lower nozzle in Table 2.

[0036]

[Table 1]

[0037]

[Table 2]

As a result, when the conventional sliding nozzle was used, only 3 charges could be cast. This is caused by the entrainment of air from the sealing part of the sliding nozzle, which causes molten steel to melt in the mold, resulting in deterioration of steel quality, and local melt loss of the joint between the collector nozzle and the immersion nozzle. Etc.

On the other hand, when the sliding nozzle of the present invention is used, the molten steel in the mold swells due to the inclusion of air from the sealing portion of the sliding nozzle.
As a result, no deterioration of steel quality and no outflow of molten steel due to local melting damage at the joint between the collector nozzle and the immersion nozzle were observed. Therefore, 6-charge casting can be performed and the sliding plate slides smoothly. No movement damage and no melting loss of the lower nozzle due to drift were observed.

[0040]

As described above, according to the sliding nozzle of the present invention, the number of joints is significantly smaller than that of the conventional sliding nozzle, so that excellent sealing performance can be obtained and the sliding plate can be obtained. Has a useful effect that it can slide smoothly and can prevent melting damage of the lower nozzle due to uneven flow.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a sliding nozzle for a molten metal container of the present invention mounted on a tundish.

2 is a cross-sectional view showing the sliding nozzle of FIG. 1 in which a sliding plate is slid.

FIG. 3 is a sectional view showing a lower nozzle of the sliding nozzle for a molten metal container according to the present invention.

FIG. 4 is a cross-sectional view showing a conventional sliding nozzle for a molten metal container attached to a tundish.

5 is a cross-sectional view showing the sliding nozzle of FIG. 4 in which a sliding plate is slid.

[Explanation of symbols]

 1 Upper Nozzle 1A Inner Hole of Upper Nozzle 2 Upper Fixing Plate 2A Through Hole of Upper Fixing Plate 3 Lower Fixing Plate 3A Through Hole of Lower Fixing Plate 4 Sliding Plate 4A Sliding Plate Through Hole 5 Driving Means 6 Collector Nozzle 7 Tan Dish 8 Bottom wall 9 Nozzle receiving brick 9A Nozzle receiving brick opening 10 Immersion nozzle 11 Upper nozzle 11A Upper nozzle inner hole 12 Fixing plate 12A Fixing plate through hole 13 Lower nozzle 13A Lower nozzle inner hole 14 Sliding plate 14A Sliding Through hole of moving plate 15 Driving means 16 Tundish 17 Bottom wall 18 Nozzle receiving brick 18A Nozzle receiving brick opening 19 Ring 19A Upper sliding ring 19B Lower sliding ring

Front Page Continuation (72) Inventor Tsuyoshi Yoshida 2-297 Nokuramachi, Tajimi-shi, Gifu Prefecture (72) Inventor Tokuyoshi Naruse 1-2-8 Marunouchi, Chiyoda-ku, Tokyo Steel Building Tokyo Ceramic Co., Ltd. (56 ) Reference JP-A-2-55660 (JP, A) JP-B-3-13936 (JP, B2)

Claims (3)

[Claims] 1. A refractory material upper nozzle vertically mounted on a bottom wall of a molten metal container, a refractory material fixing plate having a through hole horizontally fixed to a lower end of the upper nozzle, and the fixing plate. A refractory material lower nozzle fixed vertically with a space, and a refractory material sliding plate having a through hole capable of horizontally reciprocating along the lower surface of the fixing plate and the upper surface of the lower nozzle. And a driving means for horizontally reciprocating the sliding plate along the lower surface of the fixed plate and the upper surface of the lower nozzle, and the upper slide part is provided at the upper end portion of the inner hole of the lower nozzle. A refractory ring consisting of a dynamic ring and a lower flow straightening ring is fitted, and the lower portion of the lower nozzle is characterized in that it is immersed in the molten metal injected into the mold from the lower nozzle. Sly for metal container Ding nozzle. 2. A high Al ₂ O ₃ refractory having a C content of 10% or less, which is less likely to cause cracks and surface roughness, in the upper sliding ring,
In addition to the refractory, MgO, ZrO ₂ , Si
The lower rectifying ring is made of any one of refractory materials to which at least one of C is added, and the lower rectifying ring is an Al ₂ O ₃ —SiO ₂ —C refractory material having excellent melting resistance and spalling resistance,
In addition to the refractory, MgO, ZrO ₂ , Si
The sliding nozzle for a molten metal container according to claim 1, wherein the sliding nozzle comprises a refractory to which at least one of C is added. 3. The sliding nozzle according to claim 1, wherein the upper sliding ring and the lower flow straightening ring are integrally formed.