JPH105985A - Stopper for opening/closing molten metal pouring nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stopper for opening/closing a molten metal pouring nozzle difficult to crack or erosion. SOLUTION: The stopper for opening/closing is constituted so as to fit to a molten metal discharging hole arranged to the wall of a vessel for storing the molten metal and control the discharging quantity of the molten metal flowed out from this discharging hole. In such a case, at least a part of the stopper for opening/closing the molten metal pouring nozzle contacting with the molten metal, is formed with a ceramic material containing 60-80% SiC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouring nozzle opening / closing stopper for controlling an outflow amount of a molten metal used in a continuous casting apparatus or the like.

[0002]

2. Description of the Prior Art FIG. 1 is a side view of a casting machine of a continuous casting and rolling equipment for copper rough wire drawing. In this casting machine, the groove 11 of the rotating wheel 10 having the groove 11 formed on the periphery is closed with an endless steel strip 12 to form a gap 13 having a trapezoidal cross section. The gap 13 serves as a moving mold. The molten metal 14 is poured into the gap 13 and the rotating wheel 10 and the endless steel strip 12 are water-cooled from the outside. The molten metal 14 solidifies in the gap 13 and is produced as an ingot 15. The ingot 15 is continuously hot-rolled to be processed into a rough wire, and further processed into a wire such as an electric wire by wire drawing. In FIG. 1, 16 is an endless steel strip 12
Is a tundish for storing the molten metal 14 to be supplied into the gap 13.

As shown in FIG. 2, the tundish 20 is a container in which a refractory material 24 such as a high-alumina material is lined inside a steel shell 23. A hot water nozzle 22 is mounted. The tip of the pouring nozzle 22 is located above the cavity 13. The tip of the pouring nozzle opening / closing stopper 30 has a conical shape, and the tip fits into the tap hole 21. Then, the tip of the pouring nozzle opening / closing stopper 30 is connected to the tap hole.
By stopping the metal melt outflow by bringing it into close contact with 21, the pouring nozzle opening / closing stopper 30 is separated from the pouring port 21 so that the tip 31 of the pouring nozzle opening / closing stopper 30 and the pouring port
A gap is formed between the metal melt 21 and the metal melt 14 in the tundish 20 through the gap. By moving the pouring nozzle opening / closing stopper 30 concentrically toward or away from the tap hole 21, the pouring nozzle opening / closing stopper 30 is moved.
Adjust the gap between the tip 31 and the outlet 21 of the
The amount of the molten metal 14 flowing out of 21 is controlled. The pouring nozzle opening / closing stopper 30 has a conventional SUH446.
(JIS) High chromium steel was used.

[0004]

However, when the pouring nozzle opening / closing stopper is immersed in the molten metal for a long time, the crystal grains become coarse, and as a result, the heat resistance is lowered and the pouring nozzle is opened. There is a problem that the opening / closing stopper is easily melted. When the pouring nozzle opening / closing stopper is eroded, the eroded part is mixed as fine oxides in the ingot, and this foreign matter mixed part does not plastically deform like the other matrix parts, so during the rolling process This caused the rolled material to break or the wire to break during the wire drawing process. For this reason, a pouring nozzle opening / closing stopper made of oxide has been proposed. However, the oxide pouring nozzle opening / closing stopper hardly melts. However, there is a problem that the molten metal enters the pouring nozzle opening / closing stopper and the pouring nozzle opening / closing stopper breaks. If a crack occurs in the pouring nozzle opening / closing stopper, the replacement is troublesome and the productivity is reduced. An object of the present invention is to provide a pouring nozzle opening / closing stopper which is hard to be broken or melted.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a pouring nozzle which is fitted to a tap hole provided on a wall of a container for storing a molten metal and controls the amount of the molten metal flowing out from the tap port. In the opening / closing stopper, at least a portion of the pouring nozzle opening / closing stopper that comes into contact with the molten metal is made of SiC 60 to 60.
A pouring nozzle opening / closing stopper characterized by being formed of a ceramic material containing 80%.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Is 60-80% SiC and the remainder is ceramics other than SiC
It is composed of materials. For ceramic materials other than SiC
Is a carbide (B _FourC, WC), nitride (SiN, AlN, BN), boride (Z
rB_Two, TiB_Two, LaB₆), Silicide (MoSi_Two), Fluoride (CaF_Two, BaF_Two, M
gF_Two), Oxide (Al_TwoO_3,MgO_Two, ZrO_Two, SiO_Two, 2Al_TwoO_Three-3SiO_Two)etc
Any ceramic material is used. In the present invention
The reason for limiting the content of SiC to 60-80% is that
When the volume is less than 60%, the molten metal is used to open and close the pouring nozzle.
Breaks into the water and breaks it.
This is because the closing stopper is easily melted. That is, the present invention
In, ceramic materials other than SiC
Contributes, but generally contains a lot of impurities. Because of this SiC
If the content is less than 60%, impurities will increase,
It becomes easier for the molten metal to enter the hopper. Also, SiC exceeds 80%
Then, the bond of SiC becomes loose and it becomes easy to melt.

[0007]

The present invention will be described below in detail with reference to examples. (Example 1) Pouring nozzle opening / closing stoppers having various compositions shown in Table 1 were produced, and the flow rate of the molten copper in the tundish was controlled by the pouring nozzle opening / closing stoppers to continuously cast and roll copper. Time went. The molten state of the pouring nozzle opening / closing stopper after continuous casting and rolling was investigated. Further, 200 kg of the rough drawn wire obtained by continuous casting and rolling was drawn into an ultrafine wire having a diameter of 50 μm, and the number of breaks was examined. Table 1 shows the results.

[0008]

[Table 1]

As is clear from Table 1, the products of the present invention (N
In o.1 to 3), no cracking or erosion occurred in the pouring nozzle opening / closing stopper, and it was excellent in productivity and wire drawing workability. In contrast, No. 4 of the comparative example had a low content of SiC, and the molten metal entered the pouring nozzle opening / closing stopper, causing cracks. . In No.5, the pouring nozzle opening / closing stopper was melted due to the large amount of SiC, and the melted portion of the pouring nozzle opening / closing stopper was mixed as foreign matter into the rough drawn wire, causing breakage during wire drawing. Occurred frequently. In No. 6 of the conventional product, the pouring nozzle opening / closing stopper was made of an oxide, so cracks occurred and replacement was troublesome and the productivity was significantly reduced. In Nos. 7 and 8, the pouring nozzle opening / closing stopper was made of stainless steel, so the amount of erosion was large, and the molten portion of the pouring nozzle opening / closing stopper was mixed as oxide into the rough drawn wire. Many breaks occurred during wire processing.

[0010]

As described above, the pouring nozzle opening / closing stopper of the present invention is resistant to cracking, and therefore can be cast stably for a long time. Also, since the pouring nozzle opening / closing stopper is not easily melted, there is little foreign matter contamination and there is little disconnection during wire drawing. Therefore, it is excellent in productivity and has an industrially remarkable effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a belt wheel type continuous casting method.

FIG. 2 is an enlarged explanatory view of a pouring nozzle opening / closing stopper used in a belt wheel type continuous casting method.

[Explanation of symbols]

 10 Rotating wheel 11 Groove 12 Endless steel strip 13 Void of trapezoidal cross section 14 Molten metal 15 Ingot 16 Guide pulley 20 Tundish 21 Outlet 22 Pouring nozzle 23 Steel shell 24 Refractory material 30 Stopper for opening / closing pouring nozzle 31 Pouring Tip of the nozzle opening / closing stopper

Claims (1)

[Claims] 1. A pouring nozzle opening / closing stopper which fits into a tap hole provided on a wall of a container for storing a molten metal and controls an outflow amount of the molten metal flowing out from the tap port. A pouring nozzle opening / closing stopper characterized in that at least a portion of the nozzle opening / closing stopper which comes into contact with the molten metal is made of a ceramic material containing 60 to 80% of SiC.