JPS60124448A - Electromagnetic stirrer for continuous casting machine - Google Patents

Abstract

PURPOSE:To prevent breakout and bulging with plural water cooled guide plates having cooling liquid passages and to obtain a billet having a solidified structure which is high in an axial ratio with stirring of high efficiency by disposing the plural guide plates so as to enclose the billet under the casting mold of a continuous casting machine in proximity to each other and mounting attachably and detachably a coil to the rear surface thereof. CONSTITUTION:A flow passage 12 for a cooling liquid is provided in each guide plate 11 and cooling water is introduced therein through an upper tube 13 and is discharged from a lower tube 14 to cool the plate 11 itself as well as to accelerate solidification of a billet 1. A coil 21 behind the plate 11 consists of a core 22 and a winding part 23. The integral mounting of the plate 11 and the core 22 of the coil 21 is accomplished by screwing bolts 24a, 24b from a common member 22a to the plate 11. The gap between the plate 11 and the billet 1 is adjusted by interposing a shim 26 via a bolt 25 between the front end face of the core 22 and the rear surface of the guide plate.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electromagnetic stirring device that is combined with a guide device installed directly below the mold or in the secondary cooling zone of a continuous casting machine. This relates to an electromagnetic stirring device used to stir molten metal, which guides the slab that leaves molten metal so as not to cause breakouts, improves the solidification structure, and improves the quality of the slab. Background Technology In recent years, in the field of continuous casting of steel and other materials, electromagnetic force has been used to improve the quality of slabs, especially the solidification structure.
For example, techniques for stirring molten steel have become widely used. The purpose of applying this electromagnetic stirring varies depending on the installation location, but for example, when targeting molds, it mainly promotes the floating of air bubbles and inclusions by making the molten steel flow. The objective is to promote the removal of defects and non-metallic inclusions. Moreover, the electromagnetic stirring device installed in the secondary cooling chamber under the mold is mainly aimed at increasing the equiaxed crystallinity.

The concept of attaching an electromagnetic stirring device to a continuous casting machine is a technology that has only recently been adopted, and the specific structure of the device has not yet been generalized. Therefore, regarding the specific example of the guide device installed in conjunction with the guide device under the mold, which is the object of the present invention, although the known technology is not clear, as an extension of the prior art, if it is installed directly under the mold, the first The formats shown in the figure and FIG. 2 are being considered.

Such a guide device directly below the casting mold prevents the cast slab with a thin solidified shell immediately below the exit of the mold 5 from being plated out or deformed by the unsolidified molten steel remaining inside, and prevents the lower end of the inner wall of the mold from being deformed. This is necessary to prevent friction, and generally foot rollers (Fig. 1) are installed in a row or a guide plate (Fig. 2) is used.

FIG. 1 shows an example of a guide device in which a seven-roller roller 8 supports the slab directly below the mold 2, and a ring-shaped coil 4 of a rotating magnetic field type is arranged behind (on the outside) thereof. In the format shown in this example, the coil 4 moves too quickly from the slab 1, so
The magnetic force attenuation is large and the stirring force is reduced, an induced current is generated in the foot roller 8, which tends to cause troubles such as electrolytic corrosion, and spray cooling of the slab 1 is structurally difficult.

, FIG. 2 shows an example of a guide device in which a guide plate 6 for coil protection, which also serves as a slab guide, is provided in front of the rotating magnetic field type filter 4. Although this type has the advantage of bringing the coil 4 closer to the slab 1, the guide plate 6
Since the slab 1 cannot be cooled, there is a risk that the slab 1 will not be cooled enough and abnormal bulging will occur. Furthermore, if the guide plate 6 has a water-cooled structure that can cool the slab, the thickness will increase,
The advantage of being close to the slab is lost.

Therefore, the present invention does not have the problems of the conventional electromagnetic stirring device installed on the mold, and preferably uses a water-cooled guide plate to match the original guiding ability of the yuzu, and to provide the necessary stirring for quality improvement. It is an object of the present invention to provide a SIL magnetic stirring device having a compact structure that can effectively obtain power.

In order to achieve the above-mentioned object, the present invention provides a plurality of guide plates facing the slab below the mold in which unsolidified molten metal remains inside and having cooling liquid flow passages in close proximity to the slab. An electromagnetic stirring device for a continuous casting machine consists of an integral structure of each guide plate and each corresponding coil, which are arranged so as to surround the core, and each guide plate is removably attached to the front surface of the core. suggest.

With such a configuration, the present invention can achieve sufficient cooling to prevent breakout and bulging, and efficient stirring to obtain a solidified structure with a high equiaxed crystal ratio; a so-called electromagnetic stirring device and a guide device are used. A compact device with a combined configuration is obtained.

Composition of the invention The present invention will be described in detail below with reference to the drawings.

The present invention is characterized in that a guide plate and an electromagnetic filter as a known guide device are combined into a compact device.

The guide plate 11 shown in the figure also cools the slab 1, and as shown in FIGS. Water is introduced and extracted from the lower discharge tube 14 to cool the gas 2, etc. and the id plate 11 itself, and at the same time cool the slab 1 to promote solidification. This guide plate 11 is supported by brackets 15, 16 and bins 1718 so that the upper side engages and supports the lower end of the mold in a vertically movable manner, and the lower side is placed on a saddle 27 provided at the upper end of the segment 2o of the support roll 19. The front surface is placed close to the slab l in which unsolidified molten steel etc. remain,
A plurality of pieces are set up and supported above the slab 1 at a desired position directly below the mold or in the secondary cooling zone so as to surround the slab 1.

A fill 21 is integrally arranged behind the guide plate 11. That is, this coil 21
2 and the winding portion 28, and further the core 22 is connected to the eighth winding portion 28.
As shown in Figure 6 or 6, the support structure is simpler if the guide plate 11 is connected by a ring-shaped common member 22a whose outer part is preferably circular and square, but the guide plate 11 may be suspended and supported independently. The core 22 of the coil 21 is integrally attached to the common member 22a (pol) 24a.

24b toward the guide F7' 11, and a shim 26 is interposed between the front end surface of the core 22 and the back surface of the guide plate via a bolt 25. This shim 26 is used when the guide plate 11 is worn out.
Used when adjusting the gap with slab 1.

In the illustrated example, the shim 26 is attached to the front end surface of the core 22, but it may be attached to the guide plate 11 conversely. If a thick liner is used, the shim 26 interposed between the shim 26 and the shim 26 can be used not only for centering alignment but also for adjustment when changing the size of the slab.

The above-mentioned Shinmei electromagnetic stirring device generates a rotating magnetic field by passing an alternating current through the coil 21, and stirs the molten steel 10 in the strand so that it forms a horizontal circular flow as shown in Figs. 8 and 6. can do.

As described in detail, according to the present invention, it is possible to guide the guide so as not to cause a small rake or out.

In addition to achieving sufficient cooling to prevent bulging, it is also possible to obtain a solidified structure with a high equiaxed crystallinity to improve the quality of the slab. In addition, (1) the device is compact because the slab guide device is integrated with the electromagnetic stirring coil body;

Therefore, compared to conventional devices, the coil can be brought closer to the slab, which improves the stirring effect and reduces the size of the device by reducing the capacity of the coil.

(11) The slab guide plate has either a closed type or an open souffle type water cooling mechanism for the slab, so it can be installed at any location directly below the mold or below where it is safe to cool the slab in the secondary cooling zone. can do.

(+++) The guide device also has a structure that can withstand wear by employing shims, etc., so it can be applied to actual operations.

Gv) Since the device is compact, it can be easily installed in an existing continuous casting machine.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 are both route maps showing known devices, Fig. 8 is a plan view showing an example of the device fR of the present invention, and Fig. 4 is a route map showing one implementation side of the device of the present invention. , Figure 5 is 4.
FIG. 6, an enlarged cross-sectional view of the illustrated example, is a plan view of an embodiment of the invention casting a master billet. 1... Slab 10... Painting 11... Guide plate 12... Coolant flow path 1
8... Supply tube 14... Discharge tube 15
, 16...Bracket 17, 18...Pin 19...
・Support roll 20...Segment 21...Coil 22...Coil core 22a...Core common member 28...Coil winding part z4a, s+4b
...Bolt 23...Bolt 26...Shim 27
Jar... Saddle Figure 1 Figure 21 Ne I Figure 3 Zj ll Figure 4 Figure 5

Claims (1)

[Claims] L: A plurality of guide plates facing the cast slab under the mold in which unsolidified molten metal is left inside, and having cooling liquid flow passages,
It is arranged so as to be close to and surround the slab, and each guide plate is removably attached to the front surface of the core of the coil, so that each guide plate and each corresponding coil are integrated. Electromagnetic stirring device for continuous casting machine.