JPS63104756A - Continuous casting apparatus for cast metal strip - Google Patents

Abstract

PURPOSE:To prevent the development of defect, such as breakdown and traverse cracking, etc., in a cast strip by arranging supporting rolls having brake at just under twin rolls, to support a part of dead weight of the cast strip suspending from the twin rolls. CONSTITUTION:Molten metal 3 from a tundish 1 is solidified on the surface of twin rolls 2 and shifted downward by rotation of the rolls 2, to become to one piece of cast strip by sticking together with two pieces of the solidified shells at a kissing point 4, leave from the rolls 2 and carry toward pinch rolls 6. At just under the rolls 2, the supporting rolls 7 having brake are arranged to hold the cast strip 5 and a part of dead weight of the cast strip 5 suspending to the rolls 2 is supported. In this way, the defect, such as breakdown, traverse cracking, edge cracking, middle part stretching, etc., in the cast strip at just under the rolls 2 is prevented.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a twin-roll continuous casting device, and in particular, in a vertical or inclined twin-roll continuous thin-walled slab casting device, the casting of a slab directly under the twin rolls is performed. This invention relates to a device for preventing the occurrence of defects such as breakage, horizontal cracking, edge cracking, and mid-elongation of slabs.

(Prior Art) In recent years, in the field of continuous metal casting, there has been a strong desire to develop casting technology for thin-walled slabs, and various devices have been proposed. There is a twin-roll continuous casting apparatus as disclosed in the publication, which supplies molten metal between a pair of rolls that rotate oppositely to produce a thin slab.

(Problem to be solved by the invention) However, although some of this type of continuous casting equipment has reached the level of industrial production, it has not yet reached the stage of perfection in terms of productivity, ensuring slab quality, etc. In the case of twin-roll continuous casting equipment, one of the reasons for this is that the equipment has become larger as the casting speed has increased, and as a result, the twin-roll continuous casting equipment has As a result, the high-temperature thin-walled slab that has solidified near the so-called kissing point of the rolls hangs for a long time from the twin rolls, and excessive force is applied to the entire slab or solidified shell of the slab with low tensile strength near the kissing point, causing the slab to freeze directly below the twin rolls. Defects such as slab breakage, transverse cracking, edge cracking, and mid-stretching are likely to occur. This tendency is especially strong when using rolls with large diameters. Conventionally, as a method to prevent this problem, a pinch roll whose circumferential speed matches that of the twin rolls is installed directly below the twin rolls. Attempts have been made to support the slab, but since it is extremely difficult to accurately match the circumferential speed, defects in the slab often increase, and this is hardly ever put into practical use.

(Means for Solving the Problems) In view of the above, the present invention installs one or more pairs of support rolls equipped with brakes directly below the twin rolls to reduce the dead weight of the slab suspended from the twin rolls. This prevents large forces from being applied to the slab near the kissing point.
Fracture of the slab directly under the twin rolls, horizontal cracking of the slab, edge cracking,
This is to prevent defects such as mid-elongation.

(Examples) The present invention will be described in detail below based on Examples. FIG. 1 is a diagram showing the configuration of an apparatus according to an embodiment of the present invention. In FIG. 6, molten liquid is injected from a tundish l into a mold consisting of a pair of cooling rolls, or twin rolls 2, and a side weir, etc. (not shown). The metal 3 solidifies on the surface of the twin rolls 2, moves downward as the twin rolls 2 rotate, and the two solidified shells are bonded together at the kissing point 4 to form a single thin slab 5.
The support roll 7 with a brake according to the present invention is installed directly below the twin roll 2, which separates from the twin roll 2 and moves in a loop toward the pinch roll 6 (the figure shows an example of one pair). , grasps the slab 5, which is easily broken or deformed due to the high temperature immediately after solidification, supports part of the weight of the slab 5 suspended on the twin rolls 2, and casts the slab directly under the twin rolls. This prevents defects such as breakage of the piece 5, lateral cracking, edge cracking, and mid-stretching.

In this embodiment, a combination of an electromagnetic coupler 8 and a fixed shaft is used as a brake attached to the support roll 7, but other electric or mechanical brakes may also be used. In either case, double roll 2 is always used during casting.
The structure is such that the braking force is controlled so that the slab 5 between the support roll 7 and the support roll 7 does not become slack.

Further, the support roll 7 is made to have a flexible structure, so that it can press the slab evenly over its entire width and grip it with pressure. Furthermore, the support role is 1
It is also possible to provide not only a pair but a plurality of pairs.

(Effects of the Invention) As described above, the device of the present invention has a structure in which a support roll with a brake is installed directly below the twin rolls to support part of the weight of the slab suspended from the twin rolls. It has the excellent effect of preventing defects such as breakage, transverse cracking, edge cracking, and mid-elongation of the slab immediately below.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an apparatus according to an embodiment of the present invention. 1... Tanditshu, 2... Double roll, 3...
Molten metal, 4... Kissing point, 5... Thin slab, 6... Pinch roll, 7... Support roll, 8... Electromagnetic coupler.

Claims (1)

[Claims] In twin-roll continuous casting equipment that produces thin slabs by supplying molten metal between a pair of opposingly rotating rolls, one or more pairs of support rolls equipped with brakes are installed directly below the twin rolls. A continuous casting device for thin-walled metal slabs, characterized in that it is configured to support part of the weight of the slab suspended from twin rolls.