JPS61219453A - Immersion nozzle for continuous casting - Google Patents

Abstract

PURPOSE:To prevent bridging and to make possible the omission of part or the greater part of a rolling stage by providing a heating element to the surface layer part of a nozzle and coating a ceramic refractory material to the outside of the heating element. CONSTITUTION:The heating element 11 is constituted on the surface layer part of the nozzle 3 and the outside of the heating element 11 is subjected to coating 12 of the refractory material. The temp. of the heating element 11 rises to heat the coating 12 when electricity is passed to the heating element 11. The coating 12 is maintained at the solidification point of the molten steel or above or at the temp. at which bridging does not arise or above. The bridging is thus obviated even in the stage of casting a thin ingot.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a continuous casting immersion nozzle/L/(pouring nozzle yv)
Regarding.

(Prior Art) FIG. 5 is a schematic diagram of a conventional continuous casting apparatus, which has a ladle lv1, a tundish 2, a nozzle Iv5, and a mold 5 as main components.

Ladle /I/1 is a pot that holds molten steel, and supplies the molten steel to tanditsh 2 from there. The tundish 2 holds a certain amount of molten steel and keeps the amount of molten steel supplied to the mold 5 through the nozzle μ5 constant. The nozzle IL15 serves as a passage for supplying molten steel from the tundish 2 to the mold 5, and is immersed to the bottom of the meniscus 4 to prevent oxidation of the molten steel. This meniscus 4 is the upper surface of the molten steel in the mold 5, and powder or the like is supplied onto this meniscus 4 to prevent oxidation on the surface of the molten steel. The mold 5 is cooled by cooling water 6, thereby cooling the molten steel,
A slab 7 is obtained.

Incidentally, in recent years, efforts have been made to obtain pieces by continuous casting in a form as close to the final product as possible with the intention of saving energy and saving processes. That is, efforts are being made to reduce the thickness of slabs.

FIG. 4 is an enlarged detailed view of the meniscus 4 in the device shown in FIG. The narrower the gap, the smaller the meniscus 4.

For this reason, the solidification shear /I/8b developed from the nozzle μ3 and the solidification sheave 1v8a developed from the mold 5 combine to form a prism.

On the other hand, as the billet is being pulled out, the bridge may break or the nozzle/I/3 may be destroyed, resulting in surface defects in the product billet, or
The drawback is that it cannot be cast.

(Problems to be Solved by the Invention) 7) The present invention aims to eliminate the drawbacks of the above-mentioned conventional submerged nozzle for continuous shite making. [7] Another object of the present invention is to provide a continuous casting immersion nozzle that enables the casting of thin slabs.

(Structure of the Present Invention) The present invention, as a means for achieving the above object, consists in coating a ceramic refractory material and providing a heating element on the surface of the nozzle. That is, the present invention is an immersion nozzle μ for continuous casting characterized in that a heating element is provided on the surface layer of the nozzle, and the outside of the heating element is coated with a ceramic refractory material.

In the present invention, the surface layer of the nozzle is directly heated by electrical current, and the temperature of this surface layer is maintained above the freezing point of molten steel, thereby eliminating the development of a solidified shell from the nozzle. For this reason, in the present invention, a resistance heating element is constructed on the surface layer of the nozzle, and the outer surface thereof is thinly coated with a refractory material.

Hereinafter, the present invention will be explained in detail based on FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of a continuous casting immersion nozzle according to an embodiment of the present invention, and FIG. 2 shows the configuration of the heating element in the same immersion nozzle.

In the present invention, as shown in FIG. 1, a heating element 11 is formed on the surface layer of the nozzle 1L15, and a refractory coating 12 is applied to the outside of the heating element 11. A discharge port 13 is provided at the tip of the nozzle 3. Further, this heating element 11 is provided with an opening 14 corresponding to the discharge port 13, as shown in FIG. The heating element 11 is preferably made of SiC or the like, and can be constructed by molding or powder coating. The coating 12 is preferably made of Si3N4 or the like.

The electrode 10 through which electricity flows is made of graphite or the like.

Next, to explain the operation of the above-mentioned immersion nozzle, the heating element 11
By passing electricity through, the temperature of the heating element 11 rises and the coating 12 is heated.

The coating 12 is maintained at a temperature above the freezing point of molten steel or above a temperature at which bridging does not occur (for example, 1400° C.). This prevents bridging from occurring even when casting thin slabs. Note that the coating 12 serves as an insulating material that prevents electricity from flowing into the molten steel.

The immersion nozzle for continuous casting of the present invention mainly uses thin slab f.
Although it is suitable for application to continuous casting equipment to be manufactured,
The present invention is not limited to this, and can also be applied to complex-shaped slabs, such as beam blanks (H-shaped). Furthermore, the present invention can be applied not only to fixed VF type continuous casting equipment, but also to movable type continuous casting equipment such as belt type and roll type (twin roll, single mouth -/1). It is.

(Effects of the Present Invention) As described in detail above, the present invention provides a heating element on the surface layer of the nozzle, and coating the outside of the heating element with a ceramic refractory material.1. Therefore, it is possible to prevent the formation of bridges as in conventional continuous casting submerged nozzles. As a result, in the present invention, by obtaining a thin slab, the slab is shaped more closely to the final product, and the rolling process can be partially or largely omitted, resulting in the effect of realizing energy savings and process savings.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a continuous casting immersion nozzle according to an embodiment of the present invention, and FIG. 2 shows the configuration of the heating element in the same immersion nozzle. FIG. 3 is a schematic view of a conventional continuous casting apparatus, and FIG. 4 is an enlarged detailed view of the menu canine part of the apparatus shown in FIG. Sub-agents 1) Meifuku agent Ryo Hagiwara −

Claims (1)

[Claims] An immersion nozzle for continuous casting, characterized in that a heating element is provided on the surface layer of the nozzle, and the outside of the heating element is coated with a ceramic refractory material.