JP4077806B2 - Molten metal continuous casting equipment - Google Patents

Description

  The present invention relates to a molten metal continuous casting apparatus, and more particularly to an improvement of a continuous casting apparatus having a structure in which electromagnetic coils are arranged around a mold.

In continuous casting of molten metal such as steel, many methods have been proposed to improve the surface properties of the slab by controlling the oscillation mark and initial solidification. For example, as a method of using a magnetic field, Patent Document 1 discloses that in a continuous casting method in which molten metal is poured into a water-cooled mold that vibrates with a lubricant at a constant cycle and is continuously drawn out, an electromagnetic wave provided around the mold is used. A method for improving the surface properties of a slab by continuously energizing a coil with an alternating current and utilizing a magnetic force generated by an alternating magnetic field to cause a pinch force to act on the molten metal to raise it into a convex shape is disclosed. Yes.
Further, in Patent Document 2, an alternating current is applied to a solenoidal electromagnetic coil installed so as to surround a continuous casting mold wall, and the molten metal in the mold is determined from the directions of the induction current and the induction magnetic field. While applying an electromagnetic force acting in the direction of pulling away from the mold wall toward the molten metal, the amplitude or waveform of the alternating current to be energized is periodically changed by the waveform generator when the molten metal is raised in a convex shape and continuously cast. Thus, a method for stabilizing the initial solidification and improving the slab surface properties is disclosed.
JP-A 52-32824 International Publication WO96 / 05926

In addition, electromagnetic stirring technology that stirs molten steel in the mold in the horizontal direction by an electromagnetic induction device provided along the long side of the mold during continuous casting of steel has been known for a long time. Since the electromagnetic induction coil and the mold are mounted integrally, it is necessary to prepare the coil in accordance with the number of mold spare parts, and in order to ensure the speed of mold replacement, the coil and the power cable The auto-joint system that connects the two was used. Also, in a casting method in which molten metal is raised in a convex shape by applying an electromagnetic force due to an alternating magnetic field, a solenoidal electromagnetic coil that generates the alternating magnetic field is integrally provided in the mold.
FIG. 3 shows an example of an auto joint mechanism that has been used in a conventional electromagnetic stirring apparatus in a mold. Of the coil side electrode 12a and the movable side electrode 12b having the concavo-convex centering portion 11 for alignment, the movable side electrode 12b is made contactable and separable with respect to the coil side electrode 12a by the hydraulic cylinder 13, and a new coil When exchanging the electrodes, the cylinder 13 is driven to the electrode 12a to press the electrode 12b to connect.

However, the auto joint is an expensive equipment and does not cause a problem in an electromagnetic stirrer having a relatively small electric capacity. However, in a recent electromagnetic induction equipment as the object of the present invention, a high current and a high voltage are used. It is expected that this will become a large-capacity auto joint for use, and it will be further increased in size. In fact, it is not practical to adopt an auto joint. Further, in the auto joint, as shown in FIG. 3, the contact is maintained by pressing the electrodes against each other. Therefore, the enlargement is disadvantageous for maintaining the close contact, and a gap is easily generated. The generation of a gap could cause a spark phenomenon.
An object of the present invention is to provide a molten metal continuous casting apparatus that can perform stable operation without using such a problematic auto joint and is advantageous in terms of equipment cost.

The continuous casting apparatus of the present invention for solving the above-mentioned problems is a water-cooled mold comprising a pair of long sides and a pair of short sides that are vibrated at a constant period, and the molten steel meniscus portion around the mold is circulated from above the water-cooled mold. As described above, a solenoid-like electromagnetic coil is independently installed around the mold, and when the mold is removed, the coil is movable between a position where it does not interfere with the mold and a position where the mold is mounted. The position that does not interfere with the mold means a position that does not get in the way when the mold is removed or attached when the mold is replaced.
The movement of the electromagnetic coil is performed by an arm attached to one end in the longitudinal direction of the electromagnetic coil main body independent of the mold, and a mechanism for rotating the arm with an arbitrary position of the arm as a fulcrum. It is preferable to provide a connection portion with the power cable. For rotation of the arm (electromagnetic coil), appropriate known means such as a crane or a cylinder mechanism is adopted.

  According to the continuous casting apparatus of the present invention, it has a connection part that can be securely connected to the power cable without the need for a joint, and is independent from the mold when the electromagnetic coil is separated from the mold. Therefore, it is not necessary to prepare a coil for each mold, and the saving in terms of equipment is great. Further, the apparatus of the present invention has an advantage that it can be applied to a continuous casting apparatus having an electromagnetic induction device having a small capacity to a large capacity.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a plan view showing a mold and its peripheral portion when the present invention is applied to equipment for continuously casting a slab having a rectangular cross section, and FIG. 2 is a front view thereof. As shown in the figure, the casting mold is composed of a pair of long-side copper plates 3 and a pair of short-side copper plates 6 which are combined with the long-side back plate 2 and the short-side back plate having an appropriate water cooling structure. The respective back surfaces are held and fixed by 5. The short side back plate 5 is provided with a mold width variable mechanism 4, and the slab width can be arbitrarily changed by changing the relative position of the pair of short side copper plates 6. In casting, the water-cooled mold is vibrated at a constant period, and the molten metal in the mold is provided by a solenoidal electromagnetic coil 1 installed around the mold so as to circulate around the molten steel meniscus portion from the upper part of the water-cooled mold. A predetermined electromagnetic force is applied to. In other words, an alternating current is applied to the electromagnetic coil 1 and the molten metal is applied to the molten metal in the mold while applying an electromagnetic force acting in a direction to separate the molten metal from the mold wall determined from the directions of the induced current and the induced magnetic field. It is raised in a convex shape and continuously cast.

  In the present invention, as shown in the drawing, the solenoid-like electromagnetic coil 1 is disposed so as to be separated from each other independently of the mold, and when the mold is removed, such as when the mold is replaced, Is provided with a mechanism that enables movement between a position that does not interfere with the mold and a mounting position on the mold. For example, as shown in FIG. 2, one end side (right side in the figure) of the electromagnetic coil body is extended to form a coil holding arm 7, and a rotation fulcrum 8 is provided at an intermediate position of the holding arm 7, and the holding arm 7 is rotated. By rotating around the fulcrum 8, the entire electromagnetic coil 1 is rotated along the tip locus 9 shown in the figure. The broken line position 1 'in FIG. 2 shows the electromagnetic coil rotated to a position where there is no hindrance to mold removal. A connection box 10 for connecting to the power cable is provided at the rear end of the coil holding arm 7. When the electromagnetic coil 1 is rotated (tilted), the cable rotates in a state of being connected by the connection box 10 unlike the auto joint type.

  Further, the rotation mechanism of the electromagnetic coil 1 is not particularly shown, but it is lifted / suspended by a crane, a hydraulic cylinder mechanism via a link mechanism installed in the vicinity of the rotation fulcrum of the holding arm 7, a gear, etc. What is necessary is just to select an appropriate thing, such as a motor drive mechanism. In the example of the drawing, the coil is rotated around one end of the coil to avoid interference with the mold. However, in some cases, the coil completely separated from the mold is moved to another position away from the casting position and retracted. It can also be made.

The Example of the continuous casting apparatus which concerns on this invention is shown, and it is a top view which shows a casting_mold | template and its peripheral location. It is a front view of FIG. 1, and is a figure explaining the rotation state of an electromagnetic coil. It is the schematic which shows the specific example of the conventional auto joint mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic coil 2 Long side back plate 3 Long side copper plate 4 Mold width variable mechanism 5 Short side back plate 6 Short side copper plate 7 Holding arm 8 Rotating fulcrum 9 Tip locus 10 Connection box 11 Centering part 12a Coil side electrode 12b Movable side electrode 13 Hydraulic cylinder

Claims (2)

  A water-cooled mold consisting of a pair of long sides and a pair of short sides that are vibrated at a fixed period, and a solenoidal electromagnetic coil is installed independently around the mold so as to circulate around the molten steel meniscus from the top of the water-cooled mold. A continuous casting apparatus for molten metal, wherein the electromagnetic coil is movable between a position where it does not interfere with the mold and a position where the electromagnetic coil is attached to the mold when the mold is removed.   The electromagnetic coil is moved by an arm attached to one end in the longitudinal direction of the electromagnetic coil main body independent of the mold and a mechanism for rotating the arm with an arbitrary position of the arm as a fulcrum, and a power cable is connected to one end of the arm. The continuous casting apparatus for molten metal according to claim 1, wherein a connecting portion is provided.

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