JPS6145960Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mold for continuous casting.

Generally, when continuously casting molten metal, the molten metal is injected through a submerged nozzle into a water-cooled mold, and the injected molten metal is cooled in the mold to form a solidified shell. While being sequentially pulled out by rolls placed below the mold, cooling is accelerated by cooling water sprayed from spray nozzles placed between the rolls, resulting in a completely solidified slab.

The biggest problem in such continuous casting operations is that if the solidification shell of the slab directly below the mold is insufficient, the so-called breakout occurs when the shell breaks due to the static pressure of the molten metal being unable to support it. When casting a slab of
The length of the slab in the width direction is 5% compared to the thickness direction.
Since the amount is ~10 times higher, it is more noticeable on the short side of the slab, and this is due to the underdevelopment of solidified shell formation due to insufficient cooling of the short side. For example, when casting a slab with a thickness of 220 mm, if a depression of about 4 to 5 mm is formed at the center of the slab in the thickness direction on both short sides of the slab directly below the mold, the solidified shell However, if the static pressure of the molten metal causes a bulge of about 1 mm, it has become empirically clear that the risk of breakout becomes extremely large. There is.

Conventionally, measures to prevent the occurrence of breakout include increasing the length of the mold to increase cooling by the mold, and arranging a cooling plate directly under the mold, which prevents the slab from expanding and reduces cooling. Efforts were being made to promote this technology (for example, Japanese Patent Publication No. 44-13682, Japanese Patent Publication No. 45429-1973).

However, in the above method, even if the mold is lengthened, a gap is generated between the inner wall of the lower part of the mold and the slab due to solidification shrinkage of the slab in the lower part of the mold, and indirect cooling occurs. Not only will the expected cooling effect not be obtained, but there is also the risk that the solidified shell will be destroyed due to the increased pull-out resistance. In addition, although the above method can be expected to have some effect, due to direct cooling with cooling water, some particles may adhere to the surface of the slab in the cooling grooves formed on the slab contact surface of the cooling plate. There was a problem in that slag, scale, etc. were likely to accumulate, resulting in a decrease in cooling efficiency, and eventually cooling became impossible.

From the above-mentioned viewpoints, this invention provides a mold that can efficiently cool the slab and prevent expansion of the slab during continuous casting. A slab support having a width shorter than the width of the short side is vertically disposed at the lower end, and a spray for cooling the slab is installed in the cavity formed by the short side of the mold and the slab support. The present invention is characterized in that the nozzle is provided to support the slab pulled out from the mold and to directly cool the slab.

Next, this invention will be explained using examples and drawings.

In the drawings, Fig. 1 is a vertical cross-sectional view showing a state in which slabs are manufactured by the continuous casting mold of this invention, Fig. 2 is a side view of the continuous casting mold of this invention, and Fig. 3 is a similar view of other continuous casting molds. It is a side view showing an example of this. Reference numeral 1 denotes a mold body having a rectangular cross section consisting of long sides and short sides of the same height, 1a and 1a' are opposite short sides of the mold body 1, and 6 denotes indirect cooling performed in the mold body 1. As a result, a solidified shell 6a is gradually formed on the outer shell as the slab is drawn out with a rectangular cross section.

The lower ends of both short sides 1a, 1a' of the mold body 1 have a width shorter than the width of both short sides 1a, 1a', and are flush with the inner peripheral surfaces of both short sides 1a, 1a'. Slab supports 2, 2', which are formed on the short sides 1a, 1a' and extend in the drawing direction of the slab 6 below the lower ends of the short sides 1a, 1a', are integrally perpendicular to the short sides 1a, 1a'. It is set up. The slab supports 2, 2' are
As in the embodiment shown in the figure, both short sides 1a, 1
2a, 2 at the lower end of each side of a' with a space between them.
Two pieces may be provided as shown in FIG. 3, or one piece may be provided approximately at the lower end of the center of both short sides 1a and 1a' as in the embodiment shown in FIG. In addition, in FIG. 2, 5 is a connecting piece between the slab supports 2a and 2b. In addition, the material of the slab supports 2 and 2' is as follows:
It is made of copper, steel, cast iron, etc., and is constantly cooled by a cooling device (not shown), such as a cooling box attached to its back or a spray nozzle installed around it.

4 and 4' are both short sides 1 of the mold body 1
A spray nozzle is provided in the space formed by the lower ends of the slab supports 2 and 2', and in the embodiment shown in FIG. In the embodiment shown in FIG. , four pieces are arranged by pipes 3a, 3b on both sides of the slab support 2, which is vertically installed at the lower end of the substantially center of both short sides 1a, 1a'.

Since the continuous casting mold of this invention is constructed as described above, the slab 6 pulled out from the mold body 1 is placed on the slab support 2, on the short side of the slab where breakout is likely to occur.
2', the expansion of the molten metal due to static pressure is suppressed, and the cooling efficiency within the mold is improved. nozzle 4,
By directly cooling the slab 6 with the cooling water injected from 4', the slab 6 can be rapidly cooled and the development of the solidified shell 6a can be promoted.
Further, the slab supports 2, 2' are not particularly formed with grooves on the contact surfaces with the slab 6, and the spray nozzles 4, 4' are connected to the short sides 1a, 1a' of the mold and the slab. Since the structure is such that it is disposed in the space formed by the supports 2 and 2', the cooling efficiency may be reduced due to the accumulation of slag, scale, etc. that adheres to the surface of the slab 6. By using these methods, the occurrence of breakouts can be completely eliminated.

As mentioned above, according to the mold of this invention,
Due to the extremely simple structure, occurrence of breakout can be accurately prevented, and industrially useful effects such as smooth operation can be brought about.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a state in which a slab is manufactured by the continuous casting mold of this invention, and FIGS. 2 and 3 are side views of the continuous casting mold of this invention. In the drawings, 1...mold body, 1a, 1
a'...Mold short side, 2, 2'...Slab support,
3... Piping, 4... Spray nozzle, 5... Connecting piece, 6... Cast piece.

Claims (1)

[Claims for Utility Model Registration] In a mold for continuous casting, which has a rectangular cross-section and consists of long sides and short sides of the same height, at the lower ends of both short sides of the mold, extending below the lower ends, A strip-shaped slab support having a width shorter than the width of the short side is vertically disposed, and a space for cooling the slab is provided in the space formed by the lower end of the short side and the slab support. A mold for continuous casting, characterized in that a spray nozzle is disposed to support a slab having a rectangular cross section drawn from the mold and to directly cool the slab.