JPH03216266A - Seal packing for molten metal nozzle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a seal packing used in a nozzle joint for preventing oxidation of molten metal in continuous casting molten steel ladle and tundish.

[Prior Art] Usually, in continuous casting, molten steel is received from a ladle into a tundish, and the molten steel is continuously poured from the tundish into a mold. At this time, in order to prevent oxidation of the cast molten steel,
Molten steel is poured using various nozzles.

For example, when pouring molten steel from a ladle into a tundish, connect the air seal pipe (
(long nozzle) and its lower end is immersed in the molten steel in the tundish. Molten steel is injected into the tundish through a long nozzle while being shielded from the atmosphere.

Also, when pouring molten steel from the tundish into the mold,
An immersion nozzle is connected to the sliding nozzle at the bottom of the tundish, and its lower end is immersed in the molten steel in the mold. The molten steel is injected into the mold while being shielded from heat by a submerged nozzle to prevent oxidation.

Such an anti-oxidation nozzle is required to be easily attached and detached, and its upper end is pressed and connected to the nozzle end on the container side. A seal packing is inserted into the connection part of the nozzle in order to prevent air from entering the molten steel flow path.

Conventional seal packing is made of a soft refractory material whose main ingredients are alumina, silica, carbon, etc., and when an oxidation-preventing nozzle is pressed against a container nozzle, it collapses between the nozzles and blends into the joint surface. .

[Problems to be Solved by the Invention] However, in conventional seal bags, if the nozzle joint surface made of refractory material has irregularities due to adhesion of base metal or rough skin, and is not smooth, seal failure may occur. The molten steel is oxidized.

In addition, the nozzle joint surface collides with other parts before or during nozzle connection, and a part of the seal packing is likely to be damaged.
Popular penetrates through the damaged area and oxidizes the molten steel.

This invention was made in view of the above circumstances, and an object of the present invention is to provide a seal packing for a molten metal nozzle that can prevent oxidation of molten steel even if it is slightly damaged and has excellent sealing properties. shall be.

[Means for Solving the Problems] The seal packing for a molten metal nozzle according to the present invention is a seal packing for a molten metal nozzle that is used in a nozzle member when a nozzle portion made of a refractory material is pressed against a nozzle portion portion of a molten metal container to cause the molten metal to flow. This seal packing is inserted into the pressing connection part of the seal packing, and is characterized in that at least the outer peripheral portion thereof is made of a material that melts with the heat of the flowing molten metal.

[Function] In the seal packing for a molten metal nozzle according to the present invention, the outer periphery of the packing is made of a material with a low melting point. Therefore, when the nozzle members are connected to each other and the melt is allowed to flow, the outer circumference of the packing is melted by the heat of the molten metal, and the molten material flows into the four locations on the nozzle joint surface, improving sealing performance. In addition, the joint surface is formed into a tapered surface that slopes downward from the outer periphery toward the inner periphery (molten metal passage), and when the outer periphery of the packing melts, the molten material flows into the molten metal passage, and the unmelted packing Combined with the inner circumference, sealing performance is improved.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional view showing a nozzle connection part into which a seal packing for a molten metal nozzle according to an embodiment of the present invention is inserted;
The figure is a longitudinal sectional view schematically showing a continuous casting device. The ladle 2 is mounted on a ladle car (not shown) and transported above the continuous casting apparatus. Molten steel 3 is accommodated in the ladle 2. A swing-type support pedestal (not shown) is waiting at the parking position of the Red Car.
The ladle 2 is delivered to the support frame. A tundish 1o is arranged on the side of the support frame. The tundish 1o is mounted on a tundish car (not shown) and is carried between the ladle 2 and the mold 1'. Water-cooled cast J4 below Tandae and Lee Sung Yoo 10! ! 】3 is provided and the slab 14 is solidified and cooled.
is pulled out from the mold 13.

A collector nozzle 4 is provided in place at the bottom of the ladle 2. The ladle 2 is supported by a lifting device along with the ladle car. A device (not shown) for pressing and operating the long nozzle (air seal pipe) 5 is provided below the ladle. This pressing device presses the upper end of the long nozzle 5 against the lower end surface of the collector nozzle 4, thereby connecting both nozzles 4.5. A seal packing 20 is inserted into the joint surface of both nozzles 4.5. The lower end of the long nozzle 5 is a tundish 10
It is immersed in molten steel 3 inside.

A sliding nozzle 11 is provided at a suitable location at the bottom of the tundish 10. The sliding nozzle 11 can be adjusted in opening and opening, so that the amount of casting into the mold 13 can be controlled. The tundish 10 is supported by a lifting device along with the tundish car. A device (not shown) for pressing and operating the immersion nozzle 12 is provided below the tundish 10. This pressing device presses the upper end surface of the submerged nozzle 12 against the lower end surface of the sliding nozzle 11, thereby connecting the two nozzles 11.12. A sealing packing 20 is likewise inserted into the joint surfaces of both nozzles 11, 12. The lower end of the immersion nozzle 12 reaches the mold 13, and
Molten steel 3 is continuously cast into a mold 13 through a pair of discharge ports,
The casting }+' 1 4 is pulled out at a predetermined speed by pinch rolls.

Next, the connections between the nozzles 4, 5 and the nozzles 11, 12 will be described in detail with reference to FIG. 1 and FIGS. 3(a) to 3(C). Note that since both have substantially the same joint structure, only the connecting portion of the nozzles 4 and 5 will be described here.

The main parts of the nozzles 4 and 5 are made of a refractory material such as fired brick whose main components are alumina, silica, and carbon. The joint surfaces of both nozzles 4.5 are each formed into a tapered shape. Both nozzles 4 and 5 are in close contact with each other via a seal packing 20. This joint surface is sloped downward from the outer circumference toward the inner circumference. That is, the side of the melting/draining passage 16 is lower than the outer peripheral part.

As shown in FIG. 3(a), the inner peripheral portion 21 of the seal packing 20 is made of, for example, 65% by weight of alumina (Al201) and 20% by weight of silica (S i0 2 ). lIi amount 96
, made of a refractory having a composition of 10% by weight of carbon (C), and whose outer peripheral portion 22 is made of, for example, 70% by weight of silica,
It is made of a refractory material with a composition of 25% carbon and 5% alumina by weight. The refractory of the outer peripheral part 22 is
It is molded with a binder that softens and melts at low temperatures, such as frits or thermoplastic resin, and has a low melting point (softening point) and becomes fluid when heated to about 200 to 600°C or higher.

In this case, the seal packing 20 has a thickness of approximately 5 mm, for example.
-1, the inner diameter is about 1001, and the outer diameter is about 130.

In addition, as a modification of the seal packing 20, the third (b)
As shown in the figure, irregularities may be formed on the outer surface of the inner peripheral part 21, or as shown in FIG. You can.

Next, a case of continuous casting using a nozzle into which the seal packing is inserted will be described.

In continuous casting operations, the ladle 2 is replaced one after another, and the molten steel 3 in the ladle is passed through the long nozzle 5 to the tundish 1.
0, the tundish melt fI43 is injected into the mold 13 through the immersion nozzle 12. When the ladle 2 is empty, a new ladle 2 is carried above the tandy sosh 10, the long nozzle 5 is pressed against the collector nozzle 4, and the two are connected. A seal packing 20 is pasted to the joint surface of the long nozzle 5. Next, the ladle 2 is lowered, the lower end of the long nozzle 5 is immersed into the molten steel 3, and injection of the molten steel is started.

When the molten steel 3 flows through the flow path 16, its heat is transferred to the sill packing 20, and the outer peripheral portion 22 is softened and melted. This molten material is fluidized and flows along the joint surface toward the inner circumferential portion 21, filling the four locations with the molten material and improving the rolling properties.

According to the above-mentioned example, intrusion from the nozzle connection part was effectively prevented, oxidation of the molten steel was prevented, and the quality and yield of the slab could be improved. In particular, the ladle 2 is frequently replaced, and the nozzle joint is easily damaged.
Even if the unevenness of the joint becomes rough due to rough skin, etc.,
Good sealing performance can be ensured.

[Effects of the Invention] According to the present invention, even if the joint surface of the molten metal nozzle deteriorates due to long-term continuous use, good sealing performance can be ensured and slabs of stable quality can be provided. .

In addition, even if the surface of the refractory becomes rough during the joint,
Since reliable sealing performance can be ensured, the nozzle can be used repeatedly, and the life of the nozzle refractory can be substantially extended.

Furthermore, even if a portion of the seal packing is damaged, the melt will flow into it and repair itself, thereby avoiding a reduction in sealing performance.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view schematically showing a nozzle into which a seal packing for a molten metal nozzle according to an embodiment of the present invention is charged, Fig. 2 is a schematic view showing an outline of a continuous casting apparatus, and Fig. ) to 3(C) are longitudinal sectional views showing the seal packing, respectively. 4, 5, 11, 12, nozzle, 20; seal packing, 21; inner peripheral part, 22; outer peripheral part

Claims (1)

[Claims] When a nozzle member made of a refractory material is pressed against a nozzle member of a molten metal container to cause the molten metal to flow through, a seal packing is inserted into the pressing connection part of the nozzle member, and at least the outer periphery of the seal packing A seal packing for molten metal nozzles characterized by being made of a material that melts with heat.