JPS6144587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a horizontal continuous casting apparatus for steel.

As is well known, in horizontal continuous casting equipment,
A solidification start point of the molten steel is defined between the molten steel outlet of the tundish and the molten steel inlet of the copper mold, and a refractory member called a break ring is provided to surround this solidification start point.

Brake rings are also used as tandates.
Since it forms the contact point of the copper mold, it must have the ability to prevent molten steel from leaking in this area, and the solidified layer that begins to form each time the piece of steel is pulled out intermittently. must have the ability to separate the most upstream end of the

Therefore, in conventional horizontal continuous casting equipment,
As shown in Figure 1, a horizontal sectional view of the main parts,
Mouth part 2A of front nozzle 2 of tundish dish 1
A feed nozzle 3 having the same internal dimension as the mouth part 2A of the front nozzle 2 is connected to the feed nozzle 3, and the large chamfered mouth end 4A of the copper mold 4 is made to face the end surface 3a of the feed nozzle 3.

The copper mold 4 has a water-cooled jacket 5, and a refractory break ring 6 is attached to the corner formed by the end surface 3a of the feed nozzle 3 and the mouth end 4A to connect it to the tundish 1 side. .

The feed nozzle 3 is fixed by a presser fitting 7 which is a tundish side member.

On the other hand, the molten steel 8 flowing from the tundish 1 through the feed nozzle 3 into the copper mold 4 enters the copper mold 4 having the water cooling jacket 5, that is, the inner surface 4a of the copper mold 4 and the inner surface 6a of the break ring 6. It starts solidifying at the corner A formed by , and is successively pulled out intermittently with the length indicated by l dimension in the figure as one pitch.

Each time this drawing operation is performed, the upstream end of the coagulated layer 8A is peeled off from the inner surface 6a of the break ring 6, so the break ring 6 is significantly worn out, and even as a result of practical experiments, it can only withstand continuous use for a maximum of about 2 hours. However, the operation interruption time required to replace the brake ring 6 was longer, which was extremely uneconomical.

Based on the above-mentioned viewpoints, the present invention provides a horizontal continuous molding device that enables economical continuous casting with a long service life of break rings. It is characterized by the structure in which the feed nozzle on the tundish side and the copper mold are connected via a metal break ring to achieve the purpose.

Next, the apparatus of the present invention will be explained by way of embodiments with reference to the drawings.

FIG. 2 shows only half of the essential parts of the first embodiment of the apparatus of the present invention in a horizontal sectional view. As shown in the drawings, the device 9 of the present invention connects a refractory feed nozzle 10 on the tundish side and a copper mold 11 with a water-cooled jacket structure through an iron break ring 12 with a water-cooled jacket structure. There is.

Inner dimensions of break ring 12 and copper mold 1
The difference a from the inner dimension of 1 is 0.3 to 0.5 mm on one side.

Furthermore, a solid lubricant 13 is applied from the inner surface 11a of the copper mold 11 to the inner surface 12a of the half of the break ring 12 closer to the copper mold.
The inner surface of the half portion closer to the feed nozzle of No. 2 is in a surface condition where the molten copper 7 is easily seized.

Note that the members indicated by reference numeral 7 in the figure are a presser fitting on the tundish tray side that fixes the feed nozzle 10;
8 is the molten steel, 8A is the solidified layer, 14 and 15 are the water cooling jackets, and l' is the length of one pitch for drawing the steel billet.

In the device of the present invention having the above-mentioned configuration, the break ring 12 is made of metal (iron in this embodiment) and has a water-cooled jacket structure, so that the molten steel 8 that has exited the feed nozzle 10 flows through the break ring 1.
2 and start coagulation.

Further, in the device of this invention, the brake ring 1
2 is made of iron, the thickness of the solidified layer 8A that grows during one stop cycle in contact with the iron break ring 12, whose thermal conductivity is about 1/8 that of copper, is:
The break ring 12 is significantly thinner than the part that is in contact with the copper mold 11, and when it is pulled during the drawing cycle, the break ring 12 is the weakest part because the center part has a water-cooled structure.
The breakage occurs approximately at the center in the length direction, and the separation is extremely smooth.

Furthermore, if solid lubricant 13 is applied to the inner surface 11a of the copper mold 11 and the inner surface 12a of the half of the break ring 12 closer to the copper mold, the half of the break ring 12 closer to the feed nozzle 10, where the molten steel 8 is likely to seize, can be coated with solid lubricant 13. The solidified layer 8A that grows in contact with the inner surface 12a remains, making it easier to pull out the solidified layer 8A on the copper mold 11 side.

Furthermore, since the inner dimensions of the break ring 12 are made smaller on one side by 0.3 to 0.5 mm than the inner dimensions of the copper mold 11, movement of the solidified layer 8A becomes easier.

FIG. 3 is a horizontal sectional view showing half of the main part. In the second embodiment, a break ring 16 whose inner dimension is smaller than the inner dimension of the copper mold 11 by an amount a on 4 sides is attached to the copper mold 11. The closer half 16A is made of iron, the feed nozzle 10 closer half 16B is made of copper, and both are integrated by brazing 17, with a water cooling jacket 18 inside to prevent the growth of the solidified layer 8A from the iron half of the break ring 16. Unlike the first embodiment, the solid lubricant 13 is applied to the inner surface 16a of the break ring 16 from the half 16A to the inner surface 11a of the copper mold 11, unlike the first embodiment in that it is thinnest at the top 16A. .

As is clear from the above description, the apparatus of the present invention uses a break ring with a durable water-cooled jacket structure similar to that of a copper mold, and the growth of the solidified layer of molten steel during one stop cycle is controlled by the break ring. The break ring was made to be thinnest at approximately the center in the length direction or on the half nearer to the copper mold, and was made to break and separate from this part when being pulled out, so there was almost no damage to the break ring.
This has the excellent effect of enabling continuous molding over a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a horizontal cross-sectional view showing the connecting part between the tundish and the mold of a conventional horizontal continuous casting device, Fig. 2 is a horizontal cross-sectional view showing half of the main part of the first embodiment of the present invention, and Fig. FIG. 7 is a horizontal sectional view showing a half of the main part of the second embodiment. In the drawings, 8... Molten steel, 8A... Solidified layer, 9... Device of the present invention, 10... Feed nozzle, 11... Copper mold, 11a... Inner surface, 12, 16... Break ring, 12a, 16a... ...Inner surface, 13...Solid lubricant, 14, 15, 18...Water cooling jacket,
l'... Length for one pullout pitch.

Claims (1)

[Claims] 1. A horizontal continuous casting device, characterized in that a feed nozzle on the tundish side and a copper mold are connected via a break ring having a water-cooled jacket structure, in which at least a portion near the copper mold is made of iron-based metal.