JPH0221166Y2 - - Google Patents

Description

[Detailed description of the invention] The invention consists of twin rolls that are freely rotatable parallel to each other and spaced apart appropriately, and the molten steel formed on the twin rolls in a pool is cooled by the twin rolls. This invention relates to a twin-roll continuous casting device that continuously casts steel plates.

As shown in Fig. 1, the twin-roll continuous casting device has two cooling rolls 1, 1 installed parallel to each other at an appropriate interval, and a barrel seal plate 2 is installed in the axial direction on the cooling rolls 1, 1. In addition, side seal plates 3 are provided on both end surfaces of the rolls 1, 1 to form a molten metal tank 4. Molten steel 5 is poured into the molten metal tank 4 and is cooled by the cooling rolls 1, 1. The steel plate 7 is continuously discharged from the roll gap 6 between the rolls 1 and cast by rotating the rolls 1, 1 in the direction of the arrow shown in the figure.

The molten steel 5 in the tundish tank 4 is cooled by the cooling rolls 1, 1, and a solidified shell 8 is formed on the surface of the cooling roll 1.
is formed, joins with the other solidified shell 8, and is discharged from the roll gap 6 as a cast steel plate 7.
As shown in FIG.
The thickness gradually increases from 1 to 10 to a so-called Kittus point 10 where both solidified shells 8 meet.

Normally, the thickness of the steel plate 7 is determined by various factors such as the distance of the roll gap 6, the rotational speed of the roll 1, or the height of the molten steel 5 in the tundish tank 4.
As the casting time becomes longer, a semi-solidified phase 11 (hereinafter referred to as a solid phase) located between the solidified shell 8 and the molten steel 5 in the center grows to a large size. Cooling roll 1,1
Since the pine phase 11 itself is relatively elastic, when it grows to a certain extent, it gets caught in the roll gap 6 and is ejected, and the cross section of the cast steel plate 7 is in a state similar to that of a snake swallowing an egg. There is a problem in that a steel plate having an abnormally thick portion is cast.

In order to eliminate this state, the rotation of the cooling roll 1 should be accelerated to reach the tight point 1 where both solidified shells 8 join.
0 to near the axis of roll 1, and the tight point is 10.
This problem can be solved to some extent by suppressing the growth of the thickness of the solidified shell 8 in .

However, the speed at which the steel plate 7 is discharged from the roll gap 6 must be maintained at an advanced state that is faster than the circumferential speed of the cooling roll 1 to some extent, and even if the rotation of the roll 1 is increased, the speed at which the steel plate 7 is discharged from the roll gap 6 must be maintained at a certain level higher than the circumferential speed of the cooling roll 1. The speed cannot be increased because of the relatively narrow exit gap and the frictional forces between the roll surface and the shell. As this state progresses, the circumferential speed of the roll 1 eventually becomes higher than the discharge speed of the steel plate 7 (the advance rate is negative), and the solidified shell 8 formed on the cooling roll 1 becomes easy to slip on the surface of the roll 1, as shown in FIG. As shown in FIG. 2, a part of the solidified shell 8 rises from the surface of the roll 1, and the thickness of that part 12 becomes thinner, causing the problem of sheet breakage.

The purpose of this invention is to prevent abnormal plate thickness from occurring due to the above-mentioned pine phase, and also to ensure that steel plates of a constant thickness can be continuously cast without causing plate breakage due to a negative advance rate. The object of the present invention is to provide a twin-roll continuous casting device.

The present invention consists of twin rolls that are freely rotatable parallel to each other and spaced apart from each other to cool the molten steel while casting the steel plate, and a pool tank that forms a pool of the molten steel on the twin rolls. A continuous casting device, characterized in that an electromagnetic induction coil is provided around the outer periphery of the tundish tank to apply a downward thrust to the solidified shell and the semi-solidified material in order to prevent the phenomenon that the thickness of the plate becomes partially thick. Then, magnetic force is used to constantly apply a downward driving force to the molten steel, suppressing the huge growth of the pine phase that forms at the junction of both solidified shells, and applying a downward driving force to the formed pine phase. This prevents the solidified shell from lifting up, making it possible to always cast steel plates with uniform thickness.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a twin-roll continuous casting apparatus according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 4, reference numerals 1 and 1 are cooling rolls that are installed parallel to each other and with appropriate roll gears 6, and are rotated by a rotary drive device (not shown) in directions facing each other as shown by the arrows in the figure. Ru. A cooling device (not shown) for cooling the molten steel 5 is provided within the cooling roll 1. 4 is a barrel seal plate 2 provided in the axial direction on the roll 1
and side seal plates 3 provided on both end faces of the roll 1. The barrel seal plate 2 is made of alumina, and the side seal plate 3 is made of a non-magnetic material such as boronide. Use something that is fire resistant. An electromagnetic induction coil 13 is provided around the outer periphery of this hot water tank 4. Although not shown, the electromagnetic induction coil 13 is connected to a power source.

In the above, the molten steel 5 in the tundish tank 4 is cooled by the cooling roll 1, and from the point 9 where the barrel seal plate 2, the cooling roll 1, and the molten steel 5 contact, the solidified shell 8
is formed, both solidified shells 8 are joined at a tight point 10, and a steel plate 7 is cast from the roll gap 6.
At this time, a downward propulsive force P is constantly exerted on the molten steel 5 by the magnetic force of the electromagnetic induction coil 13, and both solidified shells 8
The pine phase 11 formed above is not allowed to grow as shown by the two-dot chain line in the figure, and a downward driving force is always given to the formed pine phase 11 so that it can be pushed out from the roll gap 6.

In addition, since a downward propulsive force always acts, the circumferential speed of the roll 1 becomes faster than the discharge speed of the steel plate 7 (the advance rate becomes negative), and the solidified shell 8 partially floats on the surface of the roll 1, causing the steel plate to break. It becomes possible to always cast the steel plate 7 with a constant thickness without causing any problems.

As is clear from what has been described in detail above, the present invention provides the following excellent effects.

(1) Since the electromagnetic induction coil exerts a downward driving force on the solidified shell and the semi-solidified material, it is possible to suppress the growth of the pine phase formed on both solidified shells, and it is possible to partially suppress the growth of the pine phase formed on both solidified shells. It is possible to prevent the phenomenon that the plate thickness becomes abnormally thick, and it is possible to always cast steel plates with a constant thickness.

(2) Since a downward driving force is always applied to the solidified shell and semi-solidified material, the advanced state of the steel plate relative to the roll circumferential speed can be maintained, so that the advanced rate does not become negative and breakage of the plate does not occur.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional twin-roll continuous casting machine, Figure 2 is a front sectional view of Figure 1, and Figure 3 is a conventional twin-roll continuous casting machine in which the steel plate to be cast is cut into strips. FIG. 4 is a partially enlarged view of the cooling roll section showing the phenomenon that occurs, and a front sectional view showing an embodiment of the twin roll continuous casting apparatus according to the present invention. In the figure, 1 is a cooling roll, 4 is a molten metal tank, 5 is molten steel, 7 is a steel plate, 8 is a solidified shell, 11 is a pine phase,
13 is an electromagnetic induction coil.

Claims (1)

[Scope of utility model registration request] A twin-roll type continuous casting device consisting of twin rolls that are freely rotatable parallel to each other and spaced apart from each other to cast a steel plate while cooling molten steel, and a pool tank for forming a pool on the twin rolls. , a twin roll type characterized in that an electromagnetic induction coil is provided on the outer periphery of the tundish tank to apply a downward thrust to the solidified shell and the semi-solidified material in order to prevent the phenomenon that the plate thickness becomes partially thick. Continuous casting equipment.