JPS598842Y2 - Long nozzle for molten metal injection - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a nozzle for pouring molten metal used in a continuous casting method, particularly a long nozzle suitable for being installed between a ladle and a tundish.

In continuous casting, when pouring molten metal from a ladle into a tundish or from a tundish into a mold, a long nozzle (immersion nozzle) is used to prevent oxidation of the poured molten metal.

Long nozzles like the ones mentioned above are subject to severe melting damage at the immersed part, and in order to deal with this, research has been conducted on the selection of nozzle structures and materials, and currently aluminum carbon oxide (A1303) is used.
C) system and silicon dioxide (SiO2) system are adopted.

In particular, the former carbon aluminum oxide materials are often used, but carbon aluminum oxide materials with large bulk density have high thermal conductivity, so molten steel and slag often adhere to them, and the sealing performance to prevent oxidation is poor. At the same time, the cost was high, so it had to be used many times.

However, when using this, not only does it require heating during use, but also there is an oxidation phenomenon during heating and after use.
There is also a limit to how many times it can be used, and it is actually extremely uneconomical.

Next, the latter silicon dioxide-based material has low thermal conductivity, less adhesion of molten steel and slag, and is advantageous in terms of cost. There is a problem.

Furthermore, when applying the lining to the inner periphery of the nozzle, conventionally a cylindrical integral body has been attached, which has the disadvantage of causing peeling and falling due to the difference in thermal expansion coefficient between the nozzle body and the lining.

This idea was made to solve the problems with conventional long nozzles as mentioned above, and the nozzle body is made of silicon dioxide-based material, and the inner periphery of the nozzle is made of highly corrosion-resistant MgO-based board. The object of the present invention is to provide a long nozzle which is advantageous in terms of cost, has excellent durability, and can be used continuously for a long period of time.

This invention will be described below based on embodiments shown in the accompanying drawings.

As shown in the figure, the elongated cylindrical nozzle body 1 is made of a highly corrosion-resistant material with low thermal conductivity and bulk specific gravity, such as a silicon dioxide-based material.

On the nozzle inner circumference 2 of the nozzle body 1, a cylindrical MgO-based, for example, magnesium oxide plate 3 is attached to the part of the nozzle inner circumference 2 where the melting damage of the part immersed in the molten steel in the tundish is severe. protected from.

The magnesium oxide plate 3 is a single flat plate that is curved into a cylindrical shape and inserted into the inner periphery of the nozzle 2, and is attached to the nozzle body 1 with an adhesive so as to prevent it from coming off.

The magnesium oxide plate 3 inserted and fixed by the above operation is made into a cylindrical shape and inserted and fixed into the nozzle inner periphery 2, so that a slit 4 is formed between both side edges of the plate. By filling the heat-resistant mortar 5 as shown in Fig. 2, the mortar 5 adheres between the slits 4 and inside the sozzle body 1, and the magnesium oxide plate 3 is fixed to the inner circumference 2 of the nozzle. ing.

In this way, the mounting of the magnesium oxide plate 3 uses the synergistic effect of the springback due to the restoring elasticity of the magnesium oxide plate 3 and the adhesive, and the adhesive force of the mortar 5, so the combination of the two effects makes it strong. You can get fixed.

As described above, according to this invention, a magnesium oxide plate is curved into a cylindrical shape and fitted to the inner periphery of the nozzle of the nozzle body, which is formed using a material with low thermal conductivity and bulk specific gravity.
Since this magnesium oxide plate is fixed by springback and the adhesive force of the adhesive and mortar filled in the slit, the nozzle body can be shaped using a silicon dioxide material that is easy to use, inexpensive, and has little adhesion to molten steel. This makes it possible to reduce nozzle manufacturing costs.

Furthermore, since the inner periphery of the nozzle is protected by a magnesium oxide plate with excellent corrosion resistance, durability against melting damage is greatly improved, and the nozzle can withstand continuous casting for long periods of time.

Furthermore, since the magnesium oxide plate is attached with this springback, adhesive, and mortar, it has excellent installation strength and is easy to use during use due to the difference in thermal expansion coefficient that occurs when conventional cylindrical linings are applied. In addition to eliminating the occurrence of falling off, the continuous casting schedule for the tundish can be freely handled by changing the thickness of the magnesium oxide plate.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the long nozzle according to this invention, Figure 2
The figure is a cross-sectional plan view of the same, and FIG. 3 is a perspective view of a magnesium oxide plate incorporated into the same. 1 is the nozzle body, 2 is the inner periphery of the nozzle, 3 is the magnesium oxide plate, 4 is the slit, and 5 is the mortar.

Claims (1)

[Scope of utility model registration request] The nozzle body is formed using a material with low thermal conductivity and bulk specific gravity, and a cylindrical magnesium oxide plate is fitted to the inner periphery of the nozzle of this nozzle body, and the springback of the magnesium oxide plate is applied. A long nozzle for pouring molten metal, characterized in that the magnesium oxide plate is prevented from coming out and is dried with mortar filled in a slit.