JPS6234455B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a shell in continuous casting equipment having a mold formed by twin mold rollers brought close to each other and a pair of long side weirs and short side weirs disposed on the rollers. Regarding the formation method.

An outline of a conventional continuous slab casting equipment using twin mold rollers will be explained based on FIG. 1. Reference numeral 1 designates twin mold rollers that approach each other; reference numerals 2 and 3 designate a pinch roller and guide roller that extend downward from directly below both rollers 1 and constitute a slab conveyance path; and reference numeral 4 designates a tundish nozzle.

In the above configuration, the molten metal 5 is injected from the nozzle 4 between both rollers 1, and both rollers 1 are rotated in the direction of arrow A to pull out the slab 6. I can't get enough _H1 . Therefore, sufficient time is not given for the impurities contained in the molten metal 5 to rise to the surface of the molten metal, making it difficult to obtain a slab 6 of good quality. Therefore, it has been considered to provide a weir 7 on both rolls 1 to ensure a sufficient surface height _H2 , but the problem here is that if the surface height _H2 is sufficiently high, the casting When the shell 8 becomes too thick at the start, when the shell 8 is sandwiched between both rollers 1, the thickness of the shell 8 becomes too large.
is subject to a strong reaction force.

Therefore, the present invention provides a shell forming method that solves these problems, and its feature is that both long side weirs are brought close to each other to reduce the contact area of the molten metal between the twin mold rollers in the mold. Next, molten metal is poured into the mold to start continuous casting, and at the same time or a little later, both long side weirs are gradually separated from each other to gradually increase the molten metal contact area of the twin mold rollers in the mold. Particularly, according to this method, the thickness of the shell does not increase at the start of casting, and the twin mold rollers are not subjected to a strong reaction force. Therefore, it is not necessary to increase the strength of the twin mold rollers and their supporting device, and it is economically efficient, and high-quality slabs can be obtained.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 2 and 3. 10 is a pair of short side weirs disposed on the ends of the twin mold roller 1; 11 is a pair of long side weirs disposed on the roller 1 between the two short side weirs 10; A sliding body 12 made of carbon, ceramic, etc. is slidably disposed on the outer peripheral surface of the slide body 12, a round rod-shaped hinge part 13 is fixed to the top surface of the sliding body 12, and a concave spherical surface of the bottom surface is attached to the hinge part 13. Weir body 14 rotatably connected
It is composed of. A guide roller 15 is rotatably supported by brackets 16 erected at both ends of the upper surface of the weir body 14, and is fitted into a guide groove 17 formed on the inner surface of the short side weir 10. As a result, the weir body 14 always maintains a vertical state. Reference numeral 18 denotes a power cylinder whose main body is connected by a pin to a fixed body and whose piston rod tip is connected by a pin to a bracket 19 of the sliding body 12, which causes the sliding body 12 to slide along the outer peripheral surface of the roller 1. .

A method for forming the shell 8 will be described based on the above configuration. First, as shown in the solid line in Figure 2, both long side weirs 1
1 are brought close to each other to reduce the contact area of the molten metal of the roller 1 in the mold 20 formed by the weirs 10, 11 and the roller 1. Next, twin mold roller 1
A starter plug (not shown) is inserted in between, and the tundish nozzle 4 is inserted into the mold 20 to inject the molten metal 5 into the mold 20. Then, the part of the molten metal 5 that comes into contact with the roller 1 is cooled and the shell 8
is formed, but the area of the shell 8 is small.
Next, the roller 1 is rotated in the direction of arrow A, the starter plug is lowered, and the slab 6 is pulled out. At the same time or a little later, the piston rod of the power cylinder 18 is reduced. Then Nagabe Weir 11
is gradually moved in the direction of arrow B, the contact area of the roller 1 in the mold 20 with the molten metal is gradually increased, and the area of the shell 8 is increased. When the long side weir 11 reaches position A in FIG. 2, the operation of the power cylinder 18 is stopped and normal continuous casting operation begins.

Depending on the casting conditions, the long side weir 11 may be
It may also be brought to position B in the figure. In this case, the area of the shell 8 becomes maximum.

As described above, according to the shell forming method in the continuous casting equipment of the present invention, continuous casting is started by injecting the molten metal into the mold while reducing the molten metal contact area of the twin mold rollers in the mold. , the thickness of the shell does not increase at the start of casting, and the twin mold rollers do not receive a strong reaction force. Therefore, there is no need to increase the strength of the twin mold rollers and their supporting device, and it is economically efficient, and high-quality slabs can be obtained. Furthermore, there is no possibility that the molten metal will splash and seize the surface of the roller.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of continuous slab casting equipment using twin mold rollers, Figs. 2 and 3 show an embodiment of the present invention, Fig. 2 is a schematic longitudinal sectional view, and Fig. 3 is FIG. 1... Twin mold roller, 5... Molten metal, 6
...Slab, 8...Ciel, 10...Short side weir, 11
... Long side weir, 12 ... Sliding body, 13 ... Hinge part, 14 ... Weir body, 18 ... Power cylinder,
20...Mold.

Claims (1)

[Claims] 1. In a slab continuous casting equipment having a mold formed by twin mold rollers brought close to each other and a pair of long side weirs and short side weirs disposed on the rollers, both the long side weirs are connected to each other. The twin mold rollers in the mold are brought close together to reduce the molten metal contact area, then the molten metal is injected into the mold to start continuous casting, and at the same time or a little later, both long side weirs are gradually separated from each other. A method for forming a shell in continuous casting equipment, which is characterized by gradually increasing the contact area of molten metal between twin mold rollers in a mold.