JPS635181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing breakout during continuous casting of thin sheets.

An example of continuous thin plate casting equipment will be explained based on FIGS. 1 to 3. 1 are twin mold rollers that approach each other; 2 and 3 are pinch rollers and guide rollers that extend downward from directly below both rollers 1 and constitute a thin plate conveyance path; 4 is a tundish nozzle;
5 and 6 are a pair of long side weirs arranged on the roller 1 in the direction of the roller axis, and a pair of short side weirs arranged in a direction perpendicular to the roller axis.

In the above configuration, the molten metal 7 is injected from the nozzle 4 between the two rollers 1 rotating in the direction of arrow B, and the molten metal 7 is cooled by the cooling water supplied into both the rollers 1 to form the long side shell 8. 9 in the direction of arrow A. However, when attempting to continuously cast the thin plate 9 at high speed using the above method, the following problems arise. In other words, the solidification rate from the forcedly cooled roller 1 side and the solidification rate from the uncooled short side weir 6 made of refractory material are significantly different, so the long length generated by the roller 1 as shown in Fig. 3 is Connection portion between side shell 8 and short side shell 10 generated by short side weir 6 [hereinafter referred to as corner portion] 1
1, and cracks occur at the corner portion 11 due to the resistance force due to friction between the short side weir 6 and this short side shell 10 and the relative strength of the short side shell 10 itself at high temperature. breakout is likely to occur.

Therefore, the present invention provides a breakout prevention method during continuous casting of thin plates that solves such problems.The present invention is characterized by twin mold rollers that approach each other, and a method for preventing breakouts during continuous casting of thin sheets. Using thin plate continuous casting equipment in which a mold is formed with a pair of long side weirs arranged in the direction of the roller axis and a pair of short side weirs arranged in a direction perpendicular to the roller axis, When pouring molten metal and pulling out the thin plate from between the twin mold rollers, the left and right pair of strips are placed in contact with the circumferential surface of the twin mold rollers from the side of the long side weir, and the two sides of the strips are placed in the mold. The purpose is to insert these strips between twin mold rollers at positions close to the center of the short side weir, and move these strips downward in synchronization with the drawing of the thin plate. According to this method, both edges of the thin plate pulled out from the twin mold rollers are reinforced by the strips and cooled, so that the connecting portion between the short side shell and the long side shell becomes thick, and that part becomes thick. Cracks are less likely to occur and there is no risk of breakout occurring.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 4 to 6. 12 is twin mold roller 1
Each reel 12 is wound with a thin plate 9 and a metal tape 13 of the same material. 14 is the short side weir 6 of the twin mold roller 1
An annular groove is formed closer to the center, 15 is a guide roller, and 16 is a cooling water injection nozzle. Note that the metal tape 13 has a width of 5 to 15 mm, for example.
A thickness of about 0.5 to 1.5 mm is used.

A method for drawing out the thin plate 9 will be explained based on the above configuration. First, pull out the metal tape 13 from each reel 12 and fit the tip into the annular groove 14 of the twin mold roller 1.
Insert between. Next, a dummy head is inserted between the twin mold rollers 1. Next, the tundish nozzle 4 is inserted into the weirs 5 and 6, and the molten metal 7 is injected between the twin mold rollers 1. Next, when the amount of molten metal 7 stored reaches a predetermined value, the thin plate 9 is pulled out from between the twin mold rollers 1 by pulling the dummy bar.
Pull it out in the direction of arrow A. At the same time, the reel 12 is rotated to feed each gold tape 13 in synchronization with the drawing speed of the thin plate 9. As a result, the metal tapes 13 clamp and cool both edges of the thin plate 9 to strengthen them, and each metal tape 13 melts into the thin plate 9.

In the above embodiment, the metal tape 13 is of the same quality as the thin plate 9.
However, as shown in FIG. 7, an endless metal tape 17 made of a material different from that of the thin plate 9 may also be used. In this case, the guide roller 15 is also formed with the same annular groove 14 of the twin mold roller 1. Therefore, the metal tape 17 will not be twisted. 18 points the metal tape 17 to arrow C
This is a drive roller for moving in the direction. In this case, the metal tape 17 is recovered without melting with the thin plate 9.

As described above, according to the present invention, both edges of the thin plate pulled out from the twin mold rollers are sandwiched and reinforced by the strips, and are also cooled, so that the connecting portion between the short side shell and the long side shell is It becomes thick-walled, making it difficult for cracks to form in that area.
There is no risk of a breakout. In addition, the strip-shaped body comes into contact with the circumferential surface of the twin mold roller and moves together with the circumferential surface of the twin mold roller,
Since a shell is generated in the same manner as in the center part by the band-shaped body without applying external force to the ends, a thin plate having the same uniform structure as the center part can be obtained at the ends.

[Brief explanation of the drawing]

1 to 3 show a conventional example, in which FIG. 1 is a longitudinal sectional view, FIG. 2 is a view taken along the - arrow in FIG. 1, and FIG. 3 is an enlarged horizontal sectional view of the main part. 4 to 6 show an embodiment of the present invention, in which FIG. 4 is a longitudinal sectional view, FIG. 5 is a plan view, and FIG. 6 is a partially cutaway front view of the main part. FIG. 7 is a longitudinal sectional view showing another embodiment of the present invention. 1...Twin mold roller, 5...Nagabe weir,
6... Short side weir, 7... Molten metal, 9... Thin plate, 13...
... Metal tape (band-shaped body), 17... Metal tape (band-shaped body).

Claims (1)

[Claims] 1 A mold is formed by twin mold rollers approaching each other, a pair of long side weirs arranged on the twin mold rollers in the direction of the roller axis, and a pair of short side weirs arranged in a direction perpendicular to the roller axis. Using continuous thin plate casting equipment, the molten metal is injected into the mold and the thin plate is pulled out from between the twin mold rollers. The strips are inserted between the twin mold rollers at positions close to the center of both short side weirs in the mold, and these strips are moved downward in synchronization with the drawing of the thin plate. A method to prevent breakouts during continuous casting of thin plates.