JPS6260184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for continuous casting of metal, and in particular to a combination mold.

In a mold with both ends open for continuous casting of molten metal, the present inventors divided the part of the mold in contact with the metal to be cast into a plurality of parts, and vibrationally isolated each part. We have proposed a mold for continuous metal casting, which is formed by connecting a vibration generator that applies vibrations of 5 to 50 KHz to any of the plurality of divided molds in contact with the metal to be cast. (Japanese Patent Application No. 1945-1983, Japanese Patent Application No. 1983-1945-
(No. 112336) This proposal provides a mold that can reduce the oscillation marks on the slab, reduce surface flaws, can be applied to a variety of mold shapes, and can reduce the amount of incident energy. It is. In other words, the mold moving parts to which high-frequency vibrations are applied are distributed at several locations, for example in the height direction and width direction, to reduce the frictional force between the mold moving parts and the slab on average. It is characterized by the fact that it is possible to freely choose whether to apply vibrations intensively to the area where the frictional force is greatest or to apply vibrations intensively to the area where the frictional force is greatest.

The present invention relates to an improvement of the above-mentioned mold, and includes a molten metal open-end mold in which a vibrating connecting plate is arranged in the form of a flange on each of the wide and narrow faces, and a high-frequency vibrator is provided on this. from the upper end of the mold to the vicinity of the meniscus by 0.05-
We propose a combination mold that actively forms a gap of 0.5 mm.

The invention will be explained below with reference to the drawings.

The open continuous casting mold of the present invention has a wide mold surface 1,
1' and mold narrow surfaces 2, 2'. A vibration connecting plate 3 is disposed in the form of a flange on each of the wide surfaces 1, 1' and the narrow surfaces 2, 2'. It is arranged to propagate. The purpose of applying high-frequency vibration to the mold is to reduce friction between the mold and the slab (solidified shell), mainly at the position where the solidified shell starts to be generated in the meniscus portion. In actual work, the rate of supply of molten steel from the tundish does not necessarily match the rate of withdrawal of the slab from the mold, and the meniscus usually fluctuates up and down by 10 to 50 mm during casting.

On the other hand, since the gap between the combination molds is machined in advance, it is impossible to adjust the height of the gap during casting according to variations in the meniscus. Therefore, a gap is provided between the combination molds from the upper ends of the wide and narrow surfaces of the combination molds to the meniscus including the above-mentioned variation width, that is, to the vicinity of the meniscus. Therefore, a gap 6 of t=0.05-0.5 mm is specially machined from the upper ends of the wide and narrow surfaces of the above-mentioned combination mold to the vicinity of the meniscus. The gap 6 is formed by narrow surfaces 2, 2' as shown in FIG.
The width may be partially ground. Further, if necessary, a material having an acoustic impedance different from that of the mold, such as a refractory material such as glass wool, may be inserted into the gap 6.

Since the present invention is configured as described above, high-frequency vibrations as incident energy propagate without interfering with each other, and therefore, high-frequency vibrations effectively act on the meniscus portion. Although the terms "wide surface" and "narrow surface" are used in the above description, cases where the internal shape of the mold to be formed is square or rectangular are of course included within the scope of the present invention.

The reason for the gap of t = 0.05-0.5mm is that uniform machining of 0.05mm or less is extremely difficult in actual work, and in experiments, high-frequency vibrations
If the thickness exceeds μm, contact may occur. while 0.5
The reason for setting it below mm is that when tightening the wide and narrow sides of the mold, if the gap is more than 0.5 mm, the mold will sag (distortion), so we set a limit value that does not cause sag. It is ivy. In addition, as mentioned above, the value of the problem in the present invention is the workability of machining,
This value is determined by mold tightening workability, and is unrelated to the size of the mold, the type of metal manufactured, etc.

Then, a high frequency wave with a power of 2 KW, a frequency of 18 KHz, and a vibration amplitude of 40 μm of the vibration coupling plate was applied. Gap t
= 0.1mm, and the mold has a width of 5 along the drawing direction.
Vertical reciprocating vibration of mm was performed. While ordinary carbon steel was cast in this mold, an 80 mm square steel material was cast at a drawing speed of 3 m/min to obtain a slab with extremely excellent surface properties.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the outline of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA' in FIG. 1. 1, 1'; wide mold surface, 2, 2'; narrow mold surface, 3;
Vibration connection plate, 4; High frequency vibrator, 5; Horn,
6; Gap.

Claims (1)

[Scope of Claims] 1. Each combined surface of a molten metal open-ended mold in which a vibration connecting plate is disposed in a flange shape on each of the wide and narrow surfaces and a high-frequency vibrator is provided on each combined surface from the upper end of the mold. A combination mold for continuous casting of metal, characterized in that a diameter of 0.05 to 0.5 mm is formed up to the vicinity of the meniscus. 2. On a part of each combination surface of the mold with open ends,
A combination mold for continuous casting of metal according to claim 1, which is formed of: