JPS5921454A - Tundish for continuous casting - Google Patents

Abstract

PURPOSE:To provide a titled tundish which permits smooth repair by providing a level difference to the horizontal channel part of a tundish connecting to the heating part for molten steel provided in the lower side wall of the tundish so as to make the bottom of said channel part higher than the bottom of the tundish body. CONSTITUTION:A heating part 4 for molten steel is mounted, freely attachably and a detachably with a connection part 18 via a horizontal channel part 12 on the outside of the lower side wall 10 of a tundish body 2 having a shell 6 enclosing the outside of the body and a refractory material 8 lined on the inside thereof. The part 4 has a side wall 10 enclosed with the shell 6 and refractory material 8 similar to the body 2 and has an electromagnetic induction heater consisting of a coil 14 and an iron core 16 to regulate the temp. of the molten steel in the body 2. The bottom of the part 12 is made higher than the bottom of the body 2 by a level difference (h) to prevent the inflow of the molten steel or the like remaining on the bottom of the tundish into the part 12 in the stage of repairing the tundish thus permitting the smooth repair of the tundish.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tundish for continuous casting, and more particularly to a tundish having a function of heating molten steel.

In continuous casting, molten steel produced in a converter, etc. is stored in a ladle and transported to the upper part of the tundish. It is transferred to a tundish, and then poured into a mold through a submerged nozzle provided at the bottom of the tundish for continuous casting. By the way, in continuous casting, the temperature of molten steel in the tundish has a very large effect on the operation and the quality of the manufactured slab. For example, if the temperature of the molten steel in the tundish is too low, slag entrapment and unevenness will occur frequently on the surface of the slab, and non-metallic inclusions will increase, making it difficult to obtain clean slabs. , the tandate nozzle (long nozzle) becomes easily clogged, making stable operation difficult. On the other hand, if the molten steel temperature is too high, the columnar crystals in the solidified structure of the slab will develop significantly, causing internal cracks, and center segregation will not only become noticeable,
Cracks are likely to occur on the surface of the slab, resulting in operational problems such as breakouts.

Therefore, it is extremely important to maintain the molten steel temperature in the tundish within an appropriate range in order to stabilize continuous casting operations and improve slab quality.

A tundish having a heating function for molten steel has been disclosed as a measure to eliminate fluctuations in the temperature of molten steel in the tundish and maintain a substantially constant appropriate temperature during continuous casting operations. For example, in JP-A-54-163730, a channel-type induction heating device is installed at the bottom or side of the tundish.
A method is disclosed in which the heating section and the tundish body are detachably attached and molten steel is heated to an appropriate temperature. However, in normal continuous casting operations, tandy flux is poured into the tundish to prevent oxidation of the molten steel, and since converter slag, etc. flowing out from the ladle is floating, a fairly thick slag layer is formed. exists.

If such slag flows into the mold, it will deteriorate the quality of the slab, so even when the bricks in the tundish are replaced, a small amount of molten steel is left in the tundish. However, in the above-mentioned conventional tundish with induction heating function,
Since the bottom of the tundish and the bottom of the channel are almost on the same level, the remaining molten steel and slag solidify, making it difficult to attach and detach the tundish body and the channel of the heating section. There was a drawback that I had to break it.

SUMMARY OF THE INVENTION An object of the present invention is to provide an effective continuous casting tundish that eliminates the drawbacks of the conventional chain tundish device having a molten steel heating function and enables smooth repair work during tundish repair.

The gist of the present invention is as follows.

That is, there is a tundish body that contains a steel shell surrounding the outside and a refractory material lined inside the steel shell, which accommodates molten steel, and a refractory material that is removably attached to the outside of the lower side wall of the tundish body. In the tundish for continuous casting, the bottom surface of the horizontal groove is lower than the bottom surface of the tundish body. This tundish for continuous casting is characterized by being provided with a height difference.

Embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a plan view showing a tundish for continuous casting according to the present invention, and FIG. 2 is a sectional view taken along the line II--II in FIG. As shown in FIGS. 1 and 2, the continuous tundish according to the present invention is composed of a tundish main body 2 and a molten steel heating section 4, which are detachably integrated. The tundish body 2 is surrounded by an iron skin 6 and the inside thereof is lined with a refractory material 8, like a conventional tundish. A horizontal groove portion 12 is provided below the side wall 10 in the longitudinal direction of the tundish body 2, and this portion is also surrounded by an iron shell 6 on the outer periphery and lined with a fireproof material 8 inside, and is constructed integrally with the tundish body 2. ing. A molten steel heating device is provided in the horizontal groove 12, and in this embodiment, an iron core 16 is provided surrounding the horizontal groove 12 and across the coil 14 and the magnetic field generated by the coil 14.
An electromagnetic induction heating device is provided to inductively heat the molten steel stored in No. 2. This heating means is not limited to induction heating, but other methods are also possible.

By the way, in a conventional tundish having a heating function, the bottom surface of the tundish main body 2 and the horizontal groove 1 of the molten steel heating section 4
Since the bottom surface of the tundish body 2 was on the same level, the horizontal groove part 12 was
However, in the present invention, as shown in FIG. is characterized by having a step of height h. The height h of the step is determined by 100~2 from the amount of remaining molten steel.
00mm is appropriate.

Since the steps are provided in this manner, even if a small amount of molten steel or slag is left inside the tundish body 2 when repairing the tundish body 2 or the molten steel heating section 4, these molten steel and slag will not be able to reach the bottom surface of the tundish body 2. The connecting portion 18 can be easily disconnected because it remains in the horizontal groove portion 12 and does not flow into the horizontal groove portion 12. Therefore, a new tundish body 2 can be used without repairing the molten steel heating section 4. The connection between the tundish main body 2 and the horizontal groove portion 12 can be easily attached and detached by attaching and detaching bolts and nuts.

As is clear from the above embodiments, the continuous casting tundish having a molten steel heating function according to the present invention has a step of 100 to 200 mm between the bottom surfaces of the horizontal groove 12 connecting the tundish main body 2 and the molten steel heating section 4. We were able to achieve the following effects.

(a) Since the tundish main body 2 and the molten steel heating section 4 can be easily attached and detached, the repair period of the tundish main body 2 can be significantly shortened, and the life of the molten steel heating section can be significantly extended.

(b) As a result of improving the workability of tundish trough repair, the amount of molten steel left inside the tundish trough can be slightly larger than before, which completely prevents slag from flowing into the mold and improves slab quality. It became possible.

Although the present invention has been described with respect to a tundish having a heating function, the technical idea of the present invention can also be applied to the case where a heating device is provided to the side wall of the ladle.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a tundish for continuous casting according to the present invention, and FIG. 2 is a sectional view taken along the line II--II in FIG. 2...Tandateishu main body, 4...molten steel heating section, 6
... Iron skin, 8 ... Fireproof material, 10 ... Side wall, 12 ... Horizontal groove, 14 ... Coil, 16 ... Iron core, 18 ... Connection part. Agent Takeo Nakaji

Claims (1)

[Claims] (1) A tundish body that houses molten steel and has an iron shell surrounding the outside and a refractory material lined inside the iron shell;
A molten steel heating section having a horizontal groove made of a refractory material and removably attached to the outside of the lower side wall of the tundish main body, and a heating device for heating the molten steel through the horizontal groove. In the tandate for casting,
A tundish for continuous casting, characterized in that the bottom surface of the horizontal groove portion is stepped so that it is higher than the bottom surface of the tundish body.