JPH0437446A - Nozzle for belt type strip continuous casting - Google Patents

Abstract

PURPOSE:To execute stable operation by arranging a tapered part downward to outer face of top part at the side forming thickness of a nozzle. CONSTITUTION:By using the nozzle 1 for belt type strip continuous casting, the strip is manufactured. Then, the tapered part 2 downward is arranged to the outer face of top part A at the side forming the thickness of nozzle 1. That is, the thickness t2 at tip part of the tapered part 2 is formed to smaller than the thickness t1 of flat part 1a. By this method, material do not stick to the tip part of the nozzle and further, splash of molten metal can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a nozzle for belt-type continuous thin plate casting for producing slabs with a flat cross section.

[Conventional technology]

A twin-belt continuous casting machine for thin plates has 20 rotating bells (opposed rotating bells having a predetermined plate width) as shown in the side sectional view of Fig. 3.
Molten metal is injected from a nozzle 21 into a mold 20 formed by a and 20b, and is pulled out from below to continuously produce a thin cast slab 22.

Since the slab 22 manufactured here has a wide and flat cross-sectional shape, the molten metal poured into the mold 20 is uniformly supplied in the width direction within the mold 20 to ensure uniform quality. Therefore, the flat part 2 of the nozzle 21
1a has a rectangular or flat cross-sectional shape as shown in the perspective view of FIG. In the figure, 21b is a water reservoir, and 21c is a sprue from the tundish.

For example, JP-A-50-61332, JP-A-60-20
In the casting method using a belt-type continuous casting machine disclosed in Publication No. 3345, etc., the nozzle length is 1200 mm and the width is 45 mm.
A nozzle with a thickness of 30m+n is shown.

In this way, the thickness of the nozzle 21 is also limited by the width of the mold 20, and the thickness of the flat part 21a is also several mm+ to 1 mm.
Because it is limited to a thin thickness of a few 0.0 mm, it is extremely unstable from a structural and strength standpoint, and heat impact resistance is also required, so the material for the nozzle is fused silica or - It is made of alumina-graphite refractory material used for molten steel injection nozzles.

[Problem to be solved by the invention]

By the way, during the injection of molten metal, depending on the flow rate of the molten metal flowing down inside the nozzle 21, as shown in FIG. This develops along the lower end surface and causes contact with the rotating belts 20a, 20b, or seizures on the surfaces of the belts 20a, 20b due to molten metal scattering, which causes a problem of inhibiting operational stability. .

The present invention solves the above problems, and provides a casting nozzle for continuous belt-type thin plate casting that prevents the generation of deposits and improves operational stability.

[Means to solve the problem]

The present invention provides a belt-type thin plate continuous casting nozzle for producing slabs with a flat cross section, characterized in that a downwardly tapered part is provided on the outer surface of the tip of the nozzle on the side where the thickness is formed. This is a nozzle for continuous casting.

[For production]

The cause of the formation of icicle-like deposits on the tip of the nozzle depends on the state of molten metal injection, but it is thought that the shape of the tip is the biggest factor. As a result of studying this point, the inventors of the present invention found that by providing a downward taper on the outer surface of the tip on the side that forms the thickness of the nozzle so that the bottom end is tapered, the amount of deposits can be greatly reduced. It is something that

This is because even if adhesion occurs, the thin tip allows the adhesion to slide downward, and as it develops, it no longer comes into contact with the rotating belt, etc., and the molten metal flows down smoothly. can be prevented from scattering.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a side cross-sectional view showing the thickness direction of a nozzle for casting wide thin-walled slabs, and FIG. 2 is a detailed view of section A in FIG. 1 showing the nozzle tip.

As shown in the figure, the flat part 1a of the nozzle 1 is formed to have a flat thickness due to constraints from the width of the mold, and a tapered part 2 is provided downward on the outer surface of the tip. It is said to be tapered.

In this example, the length of the tapered part 2 is j? =80mm.

When the operation was carried out with the thickness t2 = 5 mm at the nozzle tip, the molten metal flowed down smoothly without any deposits forming on the nozzle tip, and the molten metal did not scatter and damage the rotating belt.

〔Effect of the invention〕

As explained above (the casting nozzle of the present invention has a downwardly tapered part on the outer surface of the nozzle tip, so that deposits do not occur at the tip, and the molten metal does not scatter). Therefore, the molten metal can be smoothly poured and poured, and the casting equipment can be operated stably without being damaged.

[Brief explanation of drawings]

Figure 1 is a side sectional view showing the thickness direction of a nozzle for casting wide thin slabs, Figure 2 is a detailed view of section A in Figure 1 showing the nozzle tip, and Figure 3 is a continuous casting machine for manufacturing wide thin slabs. 4 is a perspective view showing an example of a conventional nozzle, and FIG. 5 is a side view illustrating the development of deposits at the tip of the nozzle. 1.21...Casting nozzle, la, 21a...flat part, 2...tapered part, 20a, 20b...
Rotating belt, 22... Cast slab, 23... Lower end of nozzle, 24... Adhesive agent Patent attorney Aki Sawa
Masamitsu and 1 other figure 7i1, t3 figure

Claims (1)

[Claims] A belt-type continuous thin plate casting nozzle for producing slabs with a flat cross section, characterized in that a downwardly tapered part is provided on the outer surface of the tip of the nozzle on the side where the thickness is formed. .