JPH0649411Y2 - Feed nozzle for horizontal continuous casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a feed nozzle for a horizontal continuous casting apparatus.

This invention is used for continuous casting of carbon steel, stainless steel, and other metal billets.

[Prior Art] The horizontal continuous casting machine requires less equipment cost, installation area and operating cost than the vertical continuous casting machine, and there is no stress due to bending of the slab and the internal pressure of the slab is small, so that bulging It rarely occurs. In particular, small capacity casting equipment is economically efficient. Therefore, in recent years, a horizontal continuous casting apparatus has been put into practical use for casting billets and the like.

FIG. 4 shows a vertical cross section of a connection portion between the tundish 11 and the mold 21 in a general horizontal continuous casting apparatus. As shown in the drawing, in the horizontal continuous casting apparatus, the tundish 11 and the mold 21 are in communication with each other via a sliding nozzle 14 and a feed nozzle 16. Tundish 11, sliding nozzle 14 and feed nozzle 16
Are made of normal refractory materials, zircon and alumina, respectively. The mold 21 is generally made of copper and cooled by cooling water W, and the break ring 18 is provided on the inlet side.
Is installed. The break ring 18 is boron nitride,
Made of heat resistant ceramics such as silicon nitride.
Some devices do not include the sliding nozzle 14.

The molten metal M supplied into the mold 21 is cooled by the inner peripheral surface of the mold to form a solidified shell S. The formation of the solidified shell S is started by the break ring 18. Break ring 18
The solidified shell S is prevented from growing in the opposite direction, that is, on the feed nozzle 16 side. The cast piece formed by solidifying the molten metal M is intermittently drawn from the mold 21 exit side by a drawing device (not shown) such as a pinch roll. When the cast slab is pulled out intermittently, a void is created between the break ring 18 and the end of the solidified shell S, and the molten metal M newly flows into the void to generate a new solidified shell S.

By the way, the void is in a negative pressure state, and the mold
Since the 21 and the break ring 18 are only fitted to each other, air penetrates into the space from between the joint surfaces of the two. The invading air is trapped in the molten metal M, and it causes oxidation of the molten metal or remains inside or on the surface of the slab to cause casting defects such as blow holes.

As a solution to such a problem, the actual exploitation 64-38136
There is a "break ring mounting structure for a horizontal continuous casting machine" disclosed in the publication. This break ring mounting structure hermetically seals the joint between the break ring and the molten metal cooling portion of the mold with a heat-resistant O-ring.

[Problems to be solved by the invention] Since the feed nozzle is made of a refractory material such as zircon as described above, the air permeability of the nozzle body is high (for example, 12.7 × 10 ^-3 cm ³ · cm / cm ²・ CmH ₂ O ・ sec). Further, as described above, a negative pressure is generated in the mold when the cast piece is drawn. For these reasons, outside air is sucked into the inside of the feed nozzle through the pores of the nozzle body.

In the above-mentioned conventional break ring mounting structure, since the joint between the break ring and the molten metal cooling portion of the mold is sealed by the O-ring, it is not possible to prevent suction of outside air from the outer surface of the feed nozzle to the inside of the nozzle. Further, the outside air also enters the space hermetically maintained by the O-ring through the pores of the nozzle body. Therefore, it is not possible to prevent suction of outside air from the joint between the break ring and the mold.

Although there are known techniques for impregnating or coating refractory materials, even these techniques cannot sufficiently prevent outside air from entering through the pores of the nozzle body.

Therefore, this invention is intended to provide a feed nozzle for a horizontal continuous casting apparatus in which the outside air is not sucked from the nozzle body into the inside of the nozzle or into the mold.

[Means for Solving the Problems] The feed nozzle of the first invention is a horizontal continuous casting apparatus in which a tundish and a mold are connected via a feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle. Of the tundish side end surface, the outer peripheral surface and the mold side end surface of the feed nozzle, the end surface on the outer diameter side of the annular gasket is covered with a sealing material.

The feed nozzle of the second invention is a horizontal continuous casting apparatus in which a tundish and a mold are connected via the feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle. Of these, the end surface on the inner diameter side of the annular gasket is covered with a sealing material.

The feed nozzle of the third invention is a horizontal continuous casting apparatus in which a tundish and a mold are connected via the feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle. The outer peripheral surface and the end surface on the mold side are covered with a sealing material.

Heat-resistant plastic, graphite, stainless steel, etc. are suitable as the material of the sealing material. The thickness of the sealing material is about 10 to 100 μm, although it varies depending on the material, the operating temperature and the like. If the sealing material is too thin, it is easily damaged. On the other hand, if it is too thick, when the sealing material is sandwiched between the field nozzle and the break ring, for example, the molten metal intrudes into the gap between the two and causes insertion.

To cover the tundish-side end surface, the outer peripheral surface, the mold-side end surface, and the like with a sealing material, the sealing material is adhered to these with an adhesive material. As for the end face on the tundish side and the end face on the mold side, a sealing material may be sandwiched between the feed nozzle and the sliding nozzle or the break ring.

[Operation] Since the surfaces of the feed nozzle such as the tundish side end surface, the outer peripheral surface and the mold side end surface through which the outside air passes are covered with the sealing material, even if the inside of the mold becomes a negative pressure when drawing the cast slab, the nozzle body Outside air is not sucked into the inside of the feed nozzle or into the mold through the pores.

[Embodiment] (First Embodiment) FIG. 1 shows a first embodiment of the present invention, in which a steel square billet is continuously cast. The same members as those shown in FIG. 4 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The feed nozzle 16 is fixed to the frame 23 of the mold 21 by a retainer 25. In the feed nozzle 16, the tundish side end surface 16a is in contact with the end surface of the sliding nozzle 14, and the mold side end surface 16c is in contact with the end surface of the break ring 18. Break ring 18 feed nozzle 16
And the mold 21 entrance.

In order to prevent outside air from entering from the joint between the break ring 18 and the mold 21, the end face 16 of the feed nozzle 16 on the mold side is prevented.
An O-ring 27 made of silicon rubber is mounted as an annular gasket between c and the end surface of the mold 21.

End surface 16a of the feed nozzle 16 on the tundish side, outer peripheral surface 1
A stainless steel foil 17 is adhered to an end surface of the outer surface 6b and the mold side end surface 16c on the outer diameter side of the O-ring 27 by an adhesive. The thickness of the stainless steel foil 17 is 50 μm.

As described above, the stainless steel foil 17 is bonded to the surface of the feed nozzle 16 through which the outside air passes. Therefore, air does not enter the inside of the feed nozzle 16 through the pores of the nozzle body of the feed nozzle 16. Further, in the space 28 sealed by the O-ring 27, and further in the mold 21 through the joint between the break ring 18 and the mold 21,
No air will enter.

Second Embodiment In this embodiment, the mold side end surface 16 of the feed nozzle 16 is
Of c, the end surface on the inner diameter side of the O-ring 27 is covered with an annular stainless steel foil 17. Also stainless steel foil
The outer diameter of the annular stainless steel foil 17 is smaller than the inner diameter of the O-ring 27 in order to prevent the O-ring 27 from overheating due to heat transfer from the O-ring 27.

This embodiment is used when the airtightness between the sliding nozzle 14 and the tundish side end surface 16a of the feed nozzle 16 is high, and since the wall thickness of the nozzle body is large, the outside air entering from the outer peripheral surface 16b is small. To be The annular stainless steel foil 17 prevents outside air from entering the space 28 sealed by the O-ring 27 from a relatively thin portion of the nozzle body.

Third Embodiment In this embodiment, the tundish side end surface 16a, the outer peripheral surface 16b and the mold side end surface 16c of the feed nozzle 16 are covered with the stainless steel foil 17.

This embodiment is used when the nozzle body of the feed nozzle 16 is highly breathable and the O-ring 27 is not exposed to temperatures above its heat resistance.

[Advantage of the Invention] In this invention, since the surface of the feed nozzle such as the tundish side end surface, the outer peripheral surface, and the mold side end surface through which the outside air passes is covered with the sealing material, the outside air is fed through the pores of the nozzle body. It is not sucked into the nozzle or into the mold. Therefore, the oxidation of the melt,
Alternatively, casting defects such as blowholes can be prevented, the quality of the slab and the yield can be improved, and the work for removing flaws can be omitted.

[Brief description of drawings]

1 to 3 each show an embodiment of the present invention, and FIG. 4 is a vertical cross-sectional view around a feed nozzle, and FIG. 4 is a vertical sectional view of a connecting portion between a tundish and a mold in a general horizontal continuous casting apparatus. It is a side view. 11 …… Tundish, 14 …… Sliding nozzle,
16 …… Feed nozzle, 16a …… Tundish side end of feed nozzle, 16b …… Feed nozzle outer surface, 1
6c …… Mold side end face of feed nozzle, 17 …… Stainless steel foil (seal material), 18 …… Break ring, 21 ……
Mold, 23 …… Mold frame, 25 …… Feed nozzle retainer, 27 …… O ring (annular gasket), M
...... Molten metal, S ... Solidified shell, W ... Cooling water.

Claims (3)

[Scope of utility model registration request] 1. A horizontal continuous casting apparatus in which a tundish and a mold are connected via a feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle. A feed nozzle for a horizontal continuous casting apparatus, wherein an end surface on the outer diameter side of the annular gasket of the mold side end surface is covered with a sealing material. 2. A horizontal continuous casting apparatus in which a tundish and a mold are connected via a feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle, wherein the annular gasket is one of the end faces on the mold side of the feed nozzle. A feed nozzle for a horizontal continuous casting apparatus, characterized in that an end surface on the inner diameter side is covered with a sealing material. 3. A horizontal continuous casting apparatus in which a tundish and a mold are connected via a feed nozzle, and an annular gasket is mounted between the mold and the feed nozzle. A feed nozzle for a horizontal continuous casting apparatus, characterized in that an end surface on the mold side is covered with a sealing material.