JP2018061976A - Electromagnetic brake device and continuous casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of cast slab.SOLUTION: An electromagnetic brake device, installed on a long-side plane of a continuous casting mold and for applying a magnetic field in a thickness direction of the mold to a molten metal in the mold, comprises: a whole-region magnetic field application electromagnetic coil that is arranged such that a height-directional center of an iron core is positioned lower than a discharge hole of an immersion nozzle and applies a generally uniform magnetic field over a widthwise whole region of the mold; a whole-region magnetic field application power supply that causes a magnetic field by applying a current to the whole-region magnetic field application electromagnetic coil; a partial-region magnetic field application electromagnetic coil that is configured sharing a part of the iron core with the whole-region magnetic field application electromagnetic coil and applies a generally uniform magnetic field in a widthwise partial region of the mold; and a partial-region magnetic field application power supply that causes a magnetic field by applying a current to the partial-region magnetic field application electromagnetic coil. The partial-region magnetic field application electromagnetic coil is arranged such that a magnetic flux density in a predetermined region including a widthwise center of the mold can be made smaller than magnetic flux densities in other regions.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electromagnetic brake device installed in a mold of a continuous casting machine, and a continuous casting method using a continuous casting machine provided with the electromagnetic brake device.

  In continuous casting, molten metal (for example, molten steel) once stored in the tundish is poured into the mold from above through an immersion nozzle, and the cast piece, whose outer peripheral surface is cooled and solidified, is pulled out from the lower end of the mold. Thus, continuous casting is performed. The solidified portion of the outer peripheral surface of the slab is called a solidified shell.

  In continuous casting, it is widely known that applying a DC magnetic field to a molten metal jet in a mold produces an electromagnetic brake effect that slows down the jet. Electromagnetic brake technology is widely used in continuous casting machines for slabs for plates, and various effects of electromagnetic brake technology have been reported, such as improving the quality of slabs by removing bubbles and inclusions and suppressing component mixing. (For example, Non-Patent Document 1).

  In the electromagnetic brake technology, historically, an electromagnetic brake technology in which a DC magnetic field in the mold thickness direction is applied near the exit of a pair of discharge holes provided opposite to the mold short side surface of the immersion nozzle (hereinafter, for convenience) (Also referred to as local electromagnetic brake technology) was first proposed. In such local electromagnetic brake technology, a reverse braking force can be applied to a jet of molten metal from the discharge hole (that is, the discharge flow). However, in the local electromagnetic brake technology, since the braking force does not act on the region where the magnetic field around the magnetic field application region is not applied, if the magnetic flux density is increased too much, the discharge flow branches up and down, and in the region where the magnetic field is not applied. On the contrary, strong upward flow and downward flow are formed. Therefore, it becomes difficult to exert a desired effect. Therefore, in the local electromagnetic brake technology, a method of controlling the magnetic flux density within an appropriate range has been proposed (for example, Patent Document 1).

  Here, the effects expected by suppressing the momentum of the discharge flow in the mold include the effect of suppressing the dissolution of the solidified shell by the collision flow to the short side of the mold, and the breakout due to the dissolution of the solidified shell. Suppression effect, suppression of flow around the molten metal surface to avoid the inclusion casting defect, which is a lubricant that floats on the molten metal surface, from being entrained in a strong flow, and inclusions being introduced into the slab There are an effect of suppressing the occurrence of internal defects due to, and an effect of suppressing a short-side downward flow for suppressing a crack at a bending portion during processing. Therefore, in order to obtain these effects more appropriately, an electromagnetic brake device is installed so that a magnetic field can be applied to other areas such as the vicinity of the molten metal surface and the mold short side surface in addition to the vicinity of the discharge hole of the immersion nozzle. Several variations on the position have been considered.

  After that, in the electromagnetic brake technology, the application of a technology that applies a magnetic field centered on a component in the mold thickness direction that is substantially uniform in the mold width direction, called the second generation, has progressed. In this way, the downward flow is suppressed (for example, Patent Document 2). As a result, for example, a component mixing suppression technique during continuous casting of different steel types as disclosed in Patent Document 3 has been developed. On the other hand, in the electromagnetic brake technology for applying a substantially uniform magnetic field in the mold width direction (hereinafter also referred to as a uniform electromagnetic brake technology for convenience), in order to more effectively control the flow in the vicinity of the molten metal surface, For example, as disclosed in Patent Document 4, a technique has been developed in which two stages of electromagnetic brake devices that apply a substantially uniform magnetic field in the mold width direction are installed in the height direction. Furthermore, in a configuration in which such an electromagnetic brake device is installed in two stages, a technique for independently controlling the magnetic flux density for each electromagnetic brake device has been developed (for example, Patent Document 5).

Japanese Patent Laid-Open No. 2-75455 International Publication No. 95/26243 JP-A-6-304718 JP-A-4-344858 JP-A-10-328790

“(129th and 130th Nishiyama Memorial Technology Course) Material Processing Using Electromagnetic Force”, Japan Iron and Steel Institute, April 28, 1989 H. Yamamura et al. , “Optimum Magnetic Flux Density in Quality Control of Casts with Level DC Magnetic Field in Continuous Casting Mold, ISIJ International. 41, no. 10, pp. 1229-1235 Kensuke Okazawa, 4 others, “Behavior of molten steel in a continuous casting mold using electromagnetic braking technology”, Iron and Steel, Japan Iron and Steel Institute, 1998, Vol. 84, no. 7, p. 20-25

  In continuous casting using the uniform electromagnetic brake technology described above, the magnetic flux density of the applied magnetic field does not vary with time, but an induction current is generated in the molten metal due to interference with the flow of the molten metal. Since electromagnetic force is generated by the interaction between the electric current and the applied magnetic field, the action by applying the magnetic field changes depending on the magnetic flux density distribution and the flow pattern of the molten metal. Therefore, for example, as disclosed in Non-Patent Document 2, when it is desired to minimize inclusion defects in the entire slab, an appropriate magnetic flux density may exist. In this regard, for example, in Non-Patent Document 3, in order to reduce defects (that is, internal defects) due to bubbles and inclusions in the slab, a general slab thickness of about 200 mm to 300 mm is supported. In the mold, if the magnetic flux density of the applied magnetic field is as close as possible to the limit magnetic flux density of about 0.4 T of an electromagnet with an iron core (the limit magnetic flux density is determined by the amount of magnetic saturation of the iron core), a steady casting speed of 1 m / min. It is disclosed that a rectified downflow without backflow at ˜3 m / min can be obtained at the installation position of the electromagnetic brake device, and internal defects can be minimized.

  On the other hand, in Non-Patent Document 3, in continuous casting to which uniform electromagnetic brake technology is applied, there is a counter flow opposite to the discharge flow (magnetohydrodynamics (MHD) counter flow) around the discharge flow in the magnetic field. It is described that it occurs. Therefore, for example, in continuous casting, bubbles of inert gas such as Ar gas blown from the immersion nozzle together with the molten metal are included in the discharge flow as they are, but the bubbles are discharged from the discharge holes and then floated while facing the MHD. Get on the stream and concentrate around the immersion nozzle. Therefore, for example, under general casting conditions, if the magnetic flux density exceeds about 0.1 T, the number of bubbles trapped in the slab surface layer increases. That is, the surface layer quality of the slab deteriorates.

  Thus, in continuous casting using the uniform electromagnetic brake technology, for example, when the electromagnetic brake device is driven so as to apply a magnetic field having a magnetic flux density of about 0.4 T, the internal defects of the slab are minimized. However, the surface quality may be deteriorated. That is, the quality of the slab and the surface quality are in a trade-off relationship. Therefore, in continuous casting using the uniform electromagnetic brake technology, when trying to improve the quality of the slab and the surface layer at the same time, as shown in Non-patent Document 2, It was necessary to control the interaction parameter (or the Stuart number), which is a dimensionless number expressed by the ratio of the electromagnetic brake force by the electromagnetic brake device, within an appropriate range.

  However, with such a method, it is possible to improve both the quality of the slab and the surface layer quality, which are in a trade-off relationship, to some extent, but the electromagnetic brake device is driven under conditions that take into account the balance between the two. Therefore, the effect of improving the quality of the slab, that is, improving both the inner quality and the surface layer quality, is limited.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved electromagnetic brake capable of further improving the quality of a slab in continuous casting. It is to provide an apparatus and a continuous casting method.

  In order to solve the above problems, according to one aspect of the present invention, an immersion nozzle for supplying molten metal is installed on the outer side surface of the long side surface of a continuous casting mold that is installed at the approximate center in the mold width direction. An electromagnetic brake device for applying a magnetic field in the mold thickness direction to the molten metal in the mold, below a pair of discharge holes of the immersion nozzle provided to face both short side surfaces of the mold. And a global magnetic field applying electromagnetic coil for applying a substantially uniform magnetic field over the entire region in the mold width direction to the molten metal in the mold. By applying a current to the applied electromagnetic coil, the global magnetic field application power source for generating a magnetic field by the global magnetic field application electromagnetic coil, and a configuration in which a part of the iron core is shared with the global magnetic field application electromagnetic coil, Casting By applying a current to the partial region magnetic field application electromagnetic coil for applying a substantially uniform magnetic field in a partial region in the mold width direction to the molten metal in the partial region magnetic field application electromagnetic coil, A partial area magnetic field application power source for generating a magnetic field by a partial area magnetic field application electromagnetic coil, and a template width of a magnetic flux density of the magnetic field applied by the whole area magnetic field application electromagnetic coil and the partial area magnetic field application electromagnetic coil The partial region magnetic field application electromagnetic coil is configured so that the distribution in the direction can be a distribution in which the magnetic flux density in a predetermined region including the center in the mold width direction is smaller than the magnetic flux density in other regions. An electromagnetic brake device is provided that is arranged.

  In the electromagnetic brake device, the partial region magnetic field application electromagnetic coil may be installed in the predetermined region including the center in the mold width direction.

  In order to solve the above-described problem, according to another aspect of the present invention, in the electromagnetic brake device, the whole-area magnetic field application power source and the partial area magnetic field application power source are independently driven, There is provided a continuous casting method in which continuous casting is performed while controlling the distribution in the mold width direction of the magnetic flux density of the magnetic field applied by the whole area magnetic field applying electromagnetic coil and the partial area magnetic field applying electromagnetic coil.

  In the continuous casting method, the partial region magnetic field application electromagnetic coil is installed in the predetermined region including the center in the mold width direction, and a magnetic field that cancels out the magnetic field generated by the global magnetic field application electromagnetic coil is Continuous casting may be performed in a state where the magnetic flux density of the magnetic field in the predetermined region is smaller than the magnetic flux density of the magnetic field in the other region by being generated by the partial region magnetic field applying electromagnetic coil.

  As described above, according to the present invention, the quality of a slab can be further improved in continuous casting.

It is a side view which shows the structure of the electromagnetic brake device which concerns on this embodiment. It is sectional drawing in the AA cross section of the electromagnetic brake device shown in FIG. It is a figure for demonstrating the length of the mold width direction of the 2nd electromagnetic coil of the electromagnetic brake device which concerns on this embodiment. It is a side view which shows the structure of the conventional electromagnetic brake apparatus based on a uniform electromagnetic brake technique. It is sectional drawing in the BB cross section of the electromagnetic brake device shown in FIG. It is a side view which shows the structure of the electromagnetic brake device which concerns on one modification of this embodiment. It is sectional drawing in CC cross section of the electromagnetic brake device shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In each drawing shown in this specification, the size of some constituent members may be exaggerated for explanation. The relative sizes of the members illustrated in the drawings do not necessarily accurately represent the magnitude relationship between actual members.

  In the following, an embodiment in which the object of continuous casting is steel and the molten metal is molten steel will be described as an example. However, the present invention is not limited to such an example, and the present invention may be applied to continuous casting for other metals.

(1. Configuration of electromagnetic brake device)
A configuration of an electromagnetic brake device according to a preferred embodiment of the present disclosure will be described with reference to FIGS. FIG. 1 is a side view showing the configuration of the electromagnetic brake device according to the present embodiment. FIG. 2 is a cross-sectional view of the electromagnetic brake device shown in FIG. FIG. 3 is a view for explaining the length in the mold width direction of a second electromagnetic coil, which will be described later, of the electromagnetic brake device according to the present embodiment.

  The electromagnetic brake device 10 according to the present embodiment is installed on the outer side of the long side surface of the mold 120 in a continuous casting machine, and applies a magnetic field in the mold thickness direction to the molten steel 1 in the mold 120, thereby It has a function of suppressing the flow of the molten steel 1. In FIG. 1, in order to explain the installation position of the electromagnetic brake device 10 according to the present embodiment, the mold 120 and the immersion nozzle 130 are shown together. Also in FIG. 2, in order to explain the installation position of the electromagnetic brake device 10, the mold 120 is also illustrated, and the position of the immersion nozzle 130 is schematically shown by a two-dot chain line.

  Referring to FIGS. 1 and 2, the mold 120 has a rectangular tube shape corresponding to the width and thickness of a cast piece to be cast, and a pair of short-side mold plates 123 sandwich a pair of short-side mold plates 123 from both sides. Assembled. The long side mold plate 121 and the short side mold plate 123 (hereinafter may be collectively referred to as the mold plates 121 and 123) are, for example, water-cooled copper plates provided with water channels through which cooling water flows. The mold 120 cools the molten steel 1 in contact with the mold plates 121 and 123 to produce a slab. However, the present embodiment is not limited to such an example, and the mold plates 121 and 123 may be formed of various materials that are generally used as a mold for a continuous casting machine.

  In the following description, the vertical direction (that is, the direction in which the slab is pulled out from the mold 120) is also referred to as the z-axis direction. The vertical direction is also called the height direction. Two directions orthogonal to each other in a plane (horizontal plane) perpendicular to the z-axis direction are also referred to as an x-axis direction and a y-axis direction, respectively. Further, the x-axis direction is defined as a direction parallel to the long side of the mold 120 in the horizontal plane, that is, the mold width direction, and the y-axis direction is defined as a direction parallel to the short side of the mold 120 in the horizontal plane, that is, the mold thickness direction. Define as

  Back plates 125 and 127 are provided on the outer surfaces of the mold plates 121 and 123 so as to cover the outer surfaces. The back plates 125 and 127 are made of stainless steel, for example, and are provided to reinforce the mold plates 121 and 123. Hereinafter, for the sake of distinction, the back plate 125 provided on the outer side surface of the long side mold plate 121 is also referred to as the long side side back plate 125, and the back plate 127 provided on the outer side surface of the short side mold plate 123 is referred to as the short side plate. Also referred to as a side back plate 127. As described above, since the electromagnetic brake device 10 is installed on the outer side of the long side surface of the mold 120, a magnetic field is applied to the molten steel 1 in the mold 120 via the long side back plate 125. It will be. Accordingly, at least the long-side back plate 125 of the back plates 125 and 127 can be formed of a nonmagnetic material (for example, nonmagnetic stainless steel or the like).

  The immersion nozzle 130 is installed such that its lower end is immersed in the molten steel 1 in the mold 120. Above the mold 120, a tundish (not shown) for storing the molten steel 1 is installed, and the upper end of the immersion nozzle 130 is connected to the lower end of the tundish. That is, the immersion nozzle 130 continuously supplies the molten steel 1 stored in the tundish into the mold 120. The immersion nozzle 130 is installed so as to be positioned at the approximate center of the mold 120 in the x-axis direction (mold width direction).

  The immersion nozzle 130 has a substantially cylindrical shape, and a discharge hole 131 for discharging the molten steel 1 is formed in a side wall near the lower end thereof. A pair of discharge holes 131 are provided at positions facing the short side mold plates 123 on both sides of the mold 120. In FIG. 1, the flow of molten steel 1 discharged from the discharge holes 131 (that is, the discharge flow) is schematically indicated by a thick line arrow.

  The electromagnetic brake device 10 includes an iron core member 111 (core member 111) installed so as to surround the outer surface of the mold 120, and a lead wire is provided on a part of the iron core member 111 with the y-axis direction (mold thickness direction) as the rotation axis direction. A pair of first electromagnetic coils 113 that are wound and installed so as to sandwich the mold 120 in the mold thickness direction, and a first power source 117 that applies current to the pair of first electromagnetic coils 113 A pair of second electromagnetic coils 115 configured such that a lead wire is wound around a part of the iron core member 111 with the y-axis direction as the rotation axis direction and the mold 120 is sandwiched in the mold thickness direction; And a second power source 119 for applying a current to the pair of second electromagnetic coils 115.

  The iron core member 111 is a solid member, and a portion around which the conducting wire is wound functions as an iron core (core) of the first electromagnetic coil 113 and the second electromagnetic coil 115. The iron core member 111 is formed by laminating electromagnetic steel sheets, for example. As shown in the figure, the magnetic circuit can be configured by providing the iron core member 111 so as to surround not only the portion functioning as the iron core but also the outer surface of the mold 120. Therefore, the first electromagnetic coil 113 and the first Application of the magnetic field by the second electromagnetic coil 115 can be performed more efficiently.

  The pair of first electromagnetic coils 113 has a center in the z-axis direction (vertical direction, height direction) of the iron core located below the discharge hole 131 of the immersion nozzle 130, and the length in the x-axis direction is It is configured to be longer than the width of the slab (that is, to be longer than the length of the space in the mold 120 in the x-axis direction). With such a configuration, by applying a current to the pair of first electromagnetic coils 113 by the first power source 117, a magnetic field that is substantially uniform over the entire region in the mold width direction and is directed in the mold thickness direction is generated in the mold 120. Application to the molten steel 1 becomes possible. As described above, the first electromagnetic coil 113 can apply a magnetic field corresponding to the uniform electromagnetic brake technology below the discharge hole 131 of the immersion nozzle 130. Thereby, since the flow velocity of a downward flow can be reduced, the float of an inert gas bubble and a nonmetallic inclusion is accelerated | stimulated, and the effect which improves the quality of a slab can be acquired. In the present specification, an electromagnetic coil configured to be able to apply a substantially uniform magnetic field over the entire area in the mold width direction, such as the first electromagnetic coil 113, is a partial area magnetic field applying electromagnetic to be described later. For the sake of distinction from the coil, it is also referred to as a global magnetic field application electromagnetic coil for convenience. In addition, a power source for driving the entire magnetic field application electromagnetic coil, such as the first power supply 117, is also referred to as a global magnetic field application power source for convenience.

  Here, specifically, with respect to the position in the height direction, a straight line indicating the discharge direction of the molten steel 1 passing through the center of the discharge hole 131 of the immersion nozzle 130 and the height of the iron core of the first electromagnetic coil 113. The pair of first electromagnetic coils 113 is installed so that the intersection with the center in the vertical direction (intersection A1 shown in FIG. 3) is located inside the short side surface of the mold 120. As a result, the discharge flow crosses the region where the magnetic field is applied by the first electromagnetic coil 113, that is, the region where the electromagnetic brake effectively operates, so the momentum of the discharge flow is suppressed and the flow velocity of the downward flow is reduced. Effects can be obtained more effectively.

  The pair of second electromagnetic coils 115 is configured to share a part of the iron core with the first electromagnetic coil 113. The pair of second electromagnetic coils 115 has the center in the xz plane of the iron core substantially coincided with the center of the iron core of the pair of first electromagnetic coils 113, and the length in the x-axis direction is determined by the mold. 120 is configured so as to have a predetermined length shorter than the first electromagnetic coil 113 including the center in the x-axis direction (that is, shorter than the length of the space in the mold 120 in the x-axis direction). . With such a configuration, a current is applied to the pair of second electromagnetic coils 115 by the second power source 119, so that a predetermined length shorter than the entire mold width direction of the molten steel 1 in the mold 120 including the center in the mold width direction is obtained. It is possible to apply a magnetic field that is substantially uniform in the region and that extends in the mold thickness direction to the molten steel 1 in the mold 120. In the present specification, an electromagnetic coil configured to be able to apply a substantially uniform magnetic field only to a partial region in the mold width direction, such as the second electromagnetic coil 115, is referred to as the above-mentioned whole-area magnetic field applying electromagnetic coil. For the sake of distinction, it is also referred to as a partial area magnetic field application electromagnetic coil for convenience. In addition, a power source for driving the partial area magnetic field application electromagnetic coil like the second power source 119 is also referred to as a partial area magnetic field application power source for convenience.

  Here, in the electromagnetic brake device 10, the first power source 117 that applies current to the first electromagnetic coil 113 and the second power source 119 that applies current to the second electromagnetic coil 115 are provided independently. The magnetic flux density of the magnetic field generated by the first electromagnetic coil 113 and the magnetic flux density of the magnetic field generated by the second electromagnetic coil 115 are adjusted by appropriately adjusting the amount of current applied by these power sources 117 and 119. , Each can be controlled independently. That is, in the electromagnetic brake device 10, two types of electromagnetic coils (the first electromagnetic coil 113 and the second electromagnetic coil 115) that can independently adjust the magnetic flux density are installed. According to such a configuration, a substantially uniform magnetic field is applied to the molten steel 1 in the mold 120 over the entire area in the mold width direction by the first electromagnetic coil 113, and in the mold width direction by the second electromagnetic coil 115. It is possible to further apply a substantially uniform magnetic field only to a part of the region. That is, the magnetic flux density of the magnetic field applied to the molten steel 1 in the mold 120 can be distributed in the mold width direction.

  Here, as described above, the second electromagnetic coil 115 is installed in a predetermined area including the center of the mold 120 in the mold width direction, that is, an area around the immersion nozzle 130 so that a magnetic field can be applied. Accordingly, the first power source 117 and the second power source 119 are appropriately driven, and, for example, a magnetic field that cancels the magnetic field generated by the first electromagnetic coil 113 is generated by the second electromagnetic coil 115, thereby generating a mold. In the width direction, it is possible to apply a magnetic field so that the magnetic flux density in the area around the immersion nozzle 130 is smaller than the magnetic flux density in other areas.

  By performing continuous casting while realizing such a distribution of magnetic flux density, in a region other than the periphery of the position where the immersion nozzle 130 is installed in the mold width direction, that is, in a region at a predetermined distance from the short-side mold plate 123, Since a magnetic field having a relatively large magnetic flux density is applied to the molten steel 1, the momentum at which the discharge flow collides with the short-side mold plate 123 is alleviated, and the flow velocity of the downward flow can be reduced. It becomes possible to improve the internal quality of the piece. On the other hand, a magnetic field having a relatively small magnetic flux density is applied to the molten steel 1 in the mold 120 in the region around the position where the immersion nozzle 130 is installed in the mold width direction. It is possible to reduce the flow rate of the MHD counterflow at, and to improve the surface layer quality of the slab.

  Thus, according to the present embodiment, in the electromagnetic brake technology, the distribution of the magnetic flux density of the magnetic field in the mold width direction can be adjusted as appropriate, thereby improving both the quality of the slab and the surface layer quality. Is possible.

  Note that the drive control of the first power supply 117 and the second power supply 119 (specifically, for example, the timing of applying current to the first electromagnetic coil 113 and the second electromagnetic coil 115, and the current to be applied) The control of the amount and the like) can be executed by a control device (not shown). The control device is, for example, a control board on which a processor such as a CPU, or a processor and a storage element such as a memory are mounted. Alternatively, the control device may be a general-purpose information processing device such as a PC. When the processor of the control device operates according to a predetermined program, drive control of the first power source 117 and the second power source 119 is appropriately executed.

  Here, the length of the second electromagnetic coil 115 in the mold width direction will be described in more detail with reference to FIG. In the present embodiment, as described above, the second electromagnetic coil 115 is installed for the purpose of reducing the flow rate of the MHD counterflow around the installation position of the immersion nozzle 130. Therefore, the second electromagnetic coil 115 is installed around the position where the immersion nozzle 130 is installed so that the applied magnetic field can affect the MHD counterflow. On the other hand, if the length of the second electromagnetic coil 115 in the mold width direction is too long, the length in the mold width direction of the area where only the first electromagnetic coil 113 is installed becomes relatively short, and the momentum of the discharge flow It is difficult to obtain the effect of suppressing the flow rate and lowering the flow velocity of the downward flow. Therefore, the length of the second electromagnetic coil 115 in the mold width direction is suitable for both the effect of reducing the flow rate of the MHD counterflow by itself and the effect of reducing the flow rate of the downward flow by the first electromagnetic coil 113. It can be set as obtained.

  Specifically, in order to suitably suppress the momentum of the discharge flow, the discharge flow crosses the region where the magnetic field is applied only by the first electromagnetic coil 113, that is, the region where the electromagnetic brake acts more effectively. In addition, the first electromagnetic coil 113 and the second electromagnetic coil 115 are preferably installed. This is because the effect of suppressing the momentum of the discharge flow and reducing the flow velocity of the downward flow can be obtained more effectively. Therefore, if it is assumed that the discharge flow proceeds linearly from the discharge hole 131 of the immersion nozzle 130, at least a straight line indicating the discharge direction of the molten steel 1 passing through the lower end in the height direction of the discharge hole 131 of the immersion nozzle 130 (FIG. 3). The second electromagnetic coil 115 does not exist in a region outside the intersection A2 between the first electromagnetic coil 113 and the center of the first electromagnetic coil 113 in the height direction of the iron core. Preferably only the coil 113 is present. That is, it is preferable that the inner diameter of the second electromagnetic coil 115 in the mold width direction is not more than the length W1 between the intersections A2.

  On the other hand, in order to suitably obtain the effect of reducing the flow rate of the MHD counterflow around the installation position of the immersion nozzle 130, the second electromagnetic coil 115 needs to exist at least around the installation position of the immersion nozzle 130. . Therefore, the inner diameter of the second electromagnetic coil 115 in the mold width direction is preferably equal to or larger than the outer diameter W2 of the immersion nozzle 130.

  As described above, in the present embodiment, the maximum value of the inner diameter in the mold width direction is the length W1 between the intersection points A2, and the minimum value of the inner diameter in the mold width direction is the outer diameter W2 of the immersion nozzle 130. In addition, the second electromagnetic coil 115 is configured. With such a configuration, it is possible to suitably obtain both the above-described effect of reducing the flow velocity of the downflow by the first electromagnetic coil 113 and the effect of reducing the flow velocity of the MHD counterflow by the second electromagnetic coil 115. .

  The configuration of the electromagnetic brake device according to this embodiment has been described above.

  Here, for comparison, the configuration of a conventional general electromagnetic brake device according to the uniform electromagnetic brake technology will be described with reference to FIGS. 4 and 5. FIG. 4 is a side view showing a configuration of a conventional electromagnetic brake device according to the uniform electromagnetic brake technology. 5 is a cross-sectional view of the electromagnetic brake device shown in FIG. 4 and 5, as in FIGS. 1 and 2, a continuous casting mold 120 and an immersion nozzle 130 are shown together in order to describe the installation position of the conventional electromagnetic brake device.

  Referring to FIGS. 4 and 5, the conventional electromagnetic brake device 60 includes an iron core member 611 (core member 611) installed so as to surround the outer surface of the mold 120, and a part of the iron core member 611 in the y-axis direction. A pair of electromagnetic coils 613 that are configured by winding a conductive wire as the rotation axis direction and are arranged so as to sandwich the mold 120 in the mold thickness direction, and a power source 617 that applies current to the pair of electromagnetic coils 613 are provided. .

  The iron core member 611 has the same configuration as that of the iron core member 111 of the electromagnetic brake device 10 according to this embodiment shown in FIGS. 1 and 2. Further, the pair of electromagnetic coils 613 is such that the center of the iron core in the z-axis direction is located below the discharge hole 131 of the immersion nozzle 130 and the length in the x-axis direction is longer than the width of the slab. (Ie, longer than the length of the space in the mold 120 in the x-axis direction). That is, the electromagnetic coil 613 is the same as the first electromagnetic coil 113 in the electromagnetic brake device 10 according to the present embodiment. As described above, in the electromagnetic brake device 10 according to the present embodiment, the conventional electromagnetic brake device 60 is not provided with the second electromagnetic coil 115, and only the first electromagnetic coil 113 (that is, only the whole-area magnetic field applying electromagnetic coil). ) Corresponds to those provided.

  In the electromagnetic brake device 60, by applying a current to the pair of electromagnetic coils 613 by the power source 617, a magnetic field that is substantially uniform over the entire area in the mold width direction and directed in the mold thickness direction is applied to the molten steel 1 in the mold 120. Can be applied. Thereby, since the flow velocity of a downward flow can be reduced, the effect of improving the internal quality of a slab can be acquired.

  However, in order to reliably obtain the effect of improving the quality of the slab, it is necessary to increase the magnetic flux density of the magnetic field applied by the electromagnetic coil 613 to a certain extent, but if the magnetic flux density is excessively increased, the immersion nozzle The flow velocity of the MHD counter flow that occurs in the vicinity of 130 in the direction opposite to the discharge flow increases. As described above, if the flow velocity of the MHD counterflow is high, the upward flow around the immersion nozzle 130 caused by the MHD counterflow causes bubbles of inert gas and the like to rise, and the surface layer quality of the slab deteriorates. May cause problems.

  With respect to such a problem, according to the electromagnetic brake device 10 according to the present embodiment, as described above, the first electromagnetic coil 113 and the second electromagnetic coil 115 capable of independently applying a current are installed. . Accordingly, since the magnetic flux density of the magnetic field applied to the molten steel 1 in the mold 120 can be distributed in the mold width direction, the flow velocity of the downward flow can be reduced by appropriately adjusting the distribution of the magnetic flux density. Both the effect of improving the quality of the slab by making the slab and the effect of improving the surface quality of the slab by reducing the flow velocity of the upward flow around the immersion nozzle 130 caused by the MHD counter flow Can be obtained.

  The effects obtained by the conventional electromagnetic brake device 60 include not only improving the quality of the cast slab, but also suppressing the mixing of components during so-called continuous casting, in which molten metals having different components are continuously cast. By reducing the flow velocity of the downward flow by the electromagnetic brake device 60, mixing of these different types of molten metal can be suitably suppressed when the type of molten metal is switched. In this regard, in the electromagnetic brake device 10 according to the present embodiment, there can be a distribution in the magnetic flux density of the magnetic field applied to the molten steel 1 in the mold 120 in the mold width direction. The suppression effect seems to be limited.

  However, in the electromagnetic brake device 10, as described above, the first electromagnetic coil 113 and the second electromagnetic coil 115 are configured to be able to apply current independently. Therefore, for example, if a current is not applied to the second electromagnetic coil 115 but only a current is applied to the first electromagnetic coil 113, as in the conventional electromagnetic brake device 60, it extends over the entire area in the mold width direction. It is possible to apply a substantially uniform magnetic field directed in the mold thickness direction to the molten steel 1 in the mold 120. That is, in the electromagnetic brake device 10, if it is desired to more suitably obtain the effect of suppressing mixing of components at the time of continuous casting, the first electromagnetic coil 113 is applied to the first electromagnetic coil 113 only for a predetermined time when the type of molten metal is switched. The electromagnetic brake device 10 may be driven so as to apply a current only.

  Moreover, not only when emphasizing obtaining the effect of suppressing the mixing of components during continuous casting as described above, but for example, when casting a variety with a large degree of processing, the quality of the slab is low. In the case where more importance is attached, similarly, it may be preferable to apply a magnetic field that is substantially uniform over the entire area in the mold width direction and that is directed in the mold thickness direction to the molten steel 1 in the mold 120. Even in such a case, the electromagnetic brake device 10 may be driven so that a current is applied only to the first electromagnetic coil 113.

  As described above, in the electromagnetic brake device 10, the first electromagnetic coil 113 and the second electromagnetic coil 115 are configured to be able to apply currents independently, so that the electromagnetic brake having a higher degree of freedom according to the purpose. Can be used. For example, when both surface quality and internal quality are required, a magnetic field is generated by both the first electromagnetic coil 113 and the second electromagnetic coil 115 so that an appropriate magnetic flux density distribution can be realized in the mold width direction. As described above, when the effect of suppressing the mixing of components during continuous casting is desired to be obtained more appropriately, or when the inner quality of the slab is more important, a magnetic field is generated only by the first electromagnetic coil 113. Just do it.

(2. Modification)
With reference to FIG.6 and FIG.7, the structure of the electromagnetic brake device which has another structure as a modification of this embodiment is demonstrated. FIG. 6 is a side view showing a configuration of an electromagnetic brake device according to a modification of the present embodiment. 7 is a cross-sectional view taken along the line CC of the electromagnetic brake device shown in FIG. In FIGS. 6 and 7, similarly to FIGS. 1 and 2, the continuous casting mold 120 and the immersion nozzle 130 are shown together in order to explain the installation position of the electromagnetic brake device according to this modification.

  6 and 7, the electromagnetic brake device 20 according to the present modification includes an iron core member 211 (core member 211) installed so as to surround the outer surface of the mold 120, and a portion of the iron core member 211 is y. A pair of first electromagnetic coils 213, which is configured by winding a conductive wire with the axial direction as the rotation axis direction and sandwiching the mold 120 in the mold thickness direction, and a current in the pair of first electromagnetic coils 213 And a pair of iron core members 211 that are configured such that a lead wire is wound around a part of the iron core member 211 with the y-axis direction as the rotation axis direction, and the mold 120 is sandwiched in the mold thickness direction. A conductive wire is wound around the second electromagnetic coil 215, the second power source 221 that applies current to the pair of second electromagnetic coils 215, and a part of the iron core member 211 with the y-axis direction as the rotation axis direction. Configured The mold 120 includes a third electromagnetic coils 217 of the pair being disposed so as to sandwich the mold thickness direction, and the third power source 223 for applying a current to the third electromagnetic coils 217 of the pair, the.

  The iron core member 211 has the same configuration as the iron core member 111 of the electromagnetic brake device 10 shown in FIGS. 1 and 2. Further, the pair of first electromagnetic coils 213 has the center in the z-axis direction positioned below the discharge hole 131 of the immersion nozzle 130, and the length in the x-axis direction is longer than the length in the width direction of the slab. (That is, longer than the length of the space in the mold 120 in the x-axis direction). That is, the 1st electromagnetic coil 213 is the same as the 1st electromagnetic coil 113 in the electromagnetic brake device 10 mentioned above, and respond | corresponds to a global magnetic field application electromagnetic coil. The first power source 219 corresponds to a global magnetic field application power source.

  In the electromagnetic brake device 20, by applying a current to the pair of first electromagnetic coils 213 by the first power source 219, a magnetic field that is substantially uniform over the entire area in the mold width direction and that is directed in the mold thickness direction is applied to the mold 120. It becomes possible to apply to the inner molten steel 1. Thereby, since the flow velocity of a downward flow can be reduced, the effect of improving the internal quality of a slab can be acquired.

  The pair of second electromagnetic coils 215 are configured to share a part of the iron core with the first electromagnetic coil 213. The pair of second electromagnetic coils 215 has their centers in the xz plane shifted from the center of the core of the pair of first electromagnetic coils 113 to one short side surface side in the x-axis direction. The length in the x-axis direction includes a region at a predetermined distance from one short side surface in the x-axis direction of the mold 120 and does not include a region near the center of the mold 120 in the x-axis direction. It is comprised so that it may become predetermined length shorter than the electromagnetic coil 213. With this configuration, by applying a current to the pair of second electromagnetic coils 215 by the second power source 221, a predetermined region that does not include a region near the center in the x-axis direction from one short side surface in the x-axis direction. It is possible to apply to the molten steel 1 in the mold 120 a magnetic field that is substantially uniform in the region of the distance of and is directed in the mold thickness direction.

  The pair of third electromagnetic coils 217 is configured to share a part of the iron core with the first electromagnetic coil 213. The pair of third electromagnetic coils 217 are configured symmetrically with the pair of second electromagnetic coils 215 across the center of the mold 120 in the x-axis direction. That is, the pair of third electromagnetic coils 217 have their centers in the xz plane shifted from the centers of the cores of the pair of first electromagnetic coils 113 toward the other short side surface in the x-axis direction. The length in the x-axis direction includes a region at a predetermined distance from the other short side surface of the mold 120 in the x-axis direction, and does not include a region near the center of the mold 120 in the x-axis direction. It is configured to have a predetermined length shorter than one electromagnetic coil 213. With this configuration, by applying a current to the pair of third electromagnetic coils 217 by the third power source 223, a predetermined region that does not include a region near the center in the x-axis direction from the other short side surface in the x-axis direction. It is possible to apply to the molten steel 1 in the mold 120 a magnetic field that is substantially uniform in the region of the distance of and is directed in the mold thickness direction. Thus, the 2nd electromagnetic coil 215 and the 3rd electromagnetic coil 217 respond | correspond to a partial area magnetic field application electromagnetic coil. The second power source 221 and the third power source 223 correspond to a partial area magnetic field application power source.

  Here, in the electromagnetic brake device 20, a first power source 219 that applies current to the first electromagnetic coil 213, a second power source 221 that applies current to the second electromagnetic coil 215, and a third electromagnetic coil The third power source 223 that applies current to the power source 217 is provided independently, and is generated by the first electromagnetic coil 213 by appropriately adjusting the amount of current applied by the power sources 219, 221, and 223. The magnetic flux density of the magnetic field, the magnetic flux density of the magnetic field generated by the second electromagnetic coil 215, and the magnetic flux density of the magnetic field generated by the third electromagnetic coil 217 can be controlled independently. That is, in the electromagnetic brake device 20, three types of electromagnetic coils (a first electromagnetic coil 213, a second electromagnetic coil 215, and a third electromagnetic coil 217) capable of independently adjusting the magnetic flux density are installed. Therefore, a substantially uniform magnetic field is applied to the molten steel 1 in the mold 120 over the entire area in the mold width direction by the first electromagnetic coil 213, and by the second electromagnetic coil 215 and the third electromagnetic coil 217. It becomes possible to further apply a substantially uniform magnetic field only to a partial region in the mold width direction. That is, the magnetic flux density of the magnetic field applied to the molten steel 1 in the mold 120 can be distributed in the mold width direction.

  Here, as described above, the second electromagnetic coil 215 and the third electromagnetic coil 217 do not include a region near the center of the mold 120 in the mold width direction, and each of the short sides of the mold 120 in the mold width direction. A magnetic field can be applied to a region at a predetermined distance from the surface. Accordingly, the first power supply 219, the second power supply 221 and the third power supply 223 are appropriately driven, and are generated by the first electromagnetic coil 213 by the second electromagnetic coil 215 and the third electromagnetic coil 217, for example. By generating a magnetic field that promotes the magnetic field, it is possible to apply a magnetic field so that the magnetic flux density in the area around the immersion nozzle 130 is smaller than the magnetic flux density in other areas in the mold width direction. Become.

  That is, also in the electromagnetic brake device 20 according to this modification, it is possible to realize the distribution of the magnetic flux density in the mold width direction similar to the electromagnetic brake device 10 according to the above-described embodiment. Therefore, according to the electromagnetic brake device 20, by performing continuous casting while realizing such a distribution of magnetic flux density, a region other than the vicinity of the position where the immersion nozzle 130 is installed in the mold width direction, as in the above-described embodiment. That is, in a region at a predetermined distance from the short-side mold plate 123, a magnetic field having a relatively large magnetic flux density is applied to the molten steel 1 in the mold 120, so that the discharge flow collides with the short-side mold plate 123. The momentum to be relieved, the flow velocity of the downward flow can be reduced, and the quality of the slab can be improved. On the other hand, a magnetic field having a relatively small magnetic flux density is applied to the molten steel 1 in the mold 120 in the region around the position where the immersion nozzle 130 is installed in the mold width direction. It is possible to reduce the flow rate of the MHD counterflow at, and to improve the surface layer quality of the slab.

  Thus, also in this modification, it is possible to improve both the quality of the slab and the surface layer quality by appropriately adjusting the distribution of the magnetic flux density of the magnetic field in the mold width direction in the electromagnetic brake technique.

  The positional relationship (the relationship between these lengths in the mold width direction) of the first electromagnetic coil 213, the second electromagnetic coil 215, and the third electromagnetic coil 217 in the mold width direction is the same as that in the above-described embodiment. It can be set based on the idea. That is, in the region where only the first electromagnetic coil 213 near the center in the mold width direction is installed, the effect of reducing the flow rate of the MHD counterflow can be suitably obtained, and the other first electromagnetic coils 213 can be obtained. And the second electromagnetic coil 215 or the region where the first electromagnetic coil 213 and the third electromagnetic coil 217 are installed, so that the effect of reducing the flow velocity of the downward flow can be suitably obtained. The positional relationship among the first electromagnetic coil 213, the second electromagnetic coil 215, and the third electromagnetic coil 217 can be set.

  Specifically, the length in the mold width direction of the region where only the first electromagnetic coil 213 exists is the discharge direction of the molten steel 1 passing through the lower end in the height direction of the discharge hole 131 of the immersion nozzle 130 shown in FIG. And a length W1 or less between the intersections A2 of the first electromagnetic coil 113 and the center of the second electromagnetic coil 115 in the height direction of the iron core (a straight line indicated by a thin broken line in FIG. 3). preferable. The length in the mold width direction of the region where only the first electromagnetic coil 213 exists is preferably equal to or larger than the outer diameter W2 of the immersion nozzle 130.

  The example which applied the electromagnetic brake apparatus which has the structure similar to the electromagnetic brake apparatus 10 which concerns on this embodiment demonstrated with reference to FIGS. 1-3 to the continuous casting machine actually used for operation in a steel plant. Will be described.

  The conditions for continuous casting are as follows. That is, the continuous casting machine is a vertical bending type continuous casting machine having a bending radius of 7.5 m and a vertical portion length of 2.5 m. The mold has a width of 1200 mm, a height of 900 mm, and a thickness of 250 mm. As the immersion nozzle, a two-hole nozzle provided with two discharge holes at a position facing the short side of the mold was used. The immersion nozzle was installed so that its discharge hole was located 300 mm in the depth direction from the meniscus at the center in the mold width direction. The outer diameter of the immersion nozzle is 150 mm, and the inner diameter is 90 mm. The diameter of the discharge hole is 60 mm, and the discharge angle θ is 40 degrees downward. Moreover, the electromagnetic brake device was installed with respect to the casting_mold | template so that it might have the largest magnetic flux density in the position of 500 mm in the depth direction from a meniscus. The second electromagnetic coil of the electromagnetic brake device was installed so that the center of the iron core was positioned at the center in the mold width direction, and the length in the mold width direction was 0.5 m. The steel type is an ultra-low carbon aluminum killed steel for automobiles, and the casting speed was 2.0 m / min.

  In order to confirm the effect of the present invention, continuous casting is performed under the above-mentioned conditions while variously changing the application conditions of the magnetic field in the electromagnetic brake device, and the number of bubble defects and inclusion defects in the cast slab after the casting is determined. By counting, the surface quality and internal quality of the slab were evaluated. Specifically, regarding the surface layer quality, the number of bubble defects and inclusion defects having a diameter of 100 μm or more, which were stepped and observed at a pitch of 1 mm up to a depth of 10 mm on the surface of the slab, was not applied with a magnetic field. These numbers in the condition were evaluated as a relative index with 1. As for the inner material, the number of bubble defects and inclusion defects having a diameter of 100 μm or more existing in a portion deeper than the surface layer of 10 mm of the slab, counted by observing in a cross section perpendicular to the casting direction of the slab, is the same. These numbers were evaluated as a relative index with the number being 1 under the condition where no magnetic field was applied.

  The results are shown in Table 1 below.

  In Table 1, Condition 1 is a condition for comparison, and is a case where a magnetic field is not applied by the electromagnetic brake device. Condition 2-5 corresponds to the case where the magnetic field is applied only by the first electromagnetic coil, that is, the case where the conventional electromagnetic brake device according to the uniform electromagnetic brake technology is used.

  From the results in Condition 2-5, it can be seen that when the magnetic field is applied only by the first electromagnetic coil, the quality of the slab is improved as the magnetic flux density of the applied magnetic field is increased. This is thought to be due to the fact that by increasing the magnetic flux density of the magnetic field applied over the entire area in the mold width direction, the effect of reducing the flow velocity of the downward flow and promoting the rise of bubbles and inclusions can be obtained. It is done. On the other hand, regarding the surface layer quality, when the magnetic flux density of the magnetic field to be applied is small as in conditions 2 and 3, the quality is improved as compared with the case where the magnetic field is not applied, but the magnetic flux density of the applied magnetic field is increased. As a result, it was confirmed that the quality deteriorated rather than when no magnetic field was applied (conditions 4 and 5). This is because the magnetic flux density of the magnetic field applied over the entire area in the mold width direction increases, and the generation of an MHD counterflow having a relatively large flow velocity around the immersion nozzle is promoted. This is considered to be because bubbles and inclusions are easily trapped on the surface layer of the slab.

  On the other hand, Condition 6-9 is a case where a magnetic field is applied by both the first electromagnetic coil and the second electromagnetic coil. At this time, in Condition 6-9, by applying a magnetic field by the second electromagnetic coil so as to cancel the magnetic field applied by the first electromagnetic coil, in the mold width direction, near the center where the immersion nozzle exists. The magnetic flux density distribution is realized such that the magnetic flux density is relatively small in the region and the magnetic flux density is relatively large in the region at a predetermined distance from the short side surface.

  From the results in Condition 6-9, it can be seen that in any condition, the quality of the cast slab is improved as compared with the case where no magnetic field is applied (Condition 1). Even in Condition 6-9, a magnetic field that generates an electromagnetic force that reduces the flow velocity of the downward flow is applied by the first electromagnetic coil in a region at a predetermined distance from the short side surface in the mold width direction. Therefore, it is considered that the effect of promoting the floating of bubbles and inclusions is obtained.

  On the other hand, regarding the surface quality, when the absolute value of the magnetic flux density of the magnetic field by the second electromagnetic coil is small as in conditions 6 and 7, that is, when the degree of canceling the magnetic field applied by the first electromagnetic coil is small. Although the effect of improving the surface layer quality is seen as compared with the case where no magnetic field is applied (condition 1), the improvement margin is not so large. This is presumably because the magnetic flux density of the magnetic field applied to the area around the immersion nozzle is not sufficiently low, and the flow rate of the MHD counterflow cannot be sufficiently reduced.

  Similarly, when the absolute value of the magnetic flux density of the magnetic field generated by the second electromagnetic coil is large as in condition 9 and the magnetic field applied by the first electromagnetic coil is almost completely canceled out, the magnetic field is applied in the same manner. Although the effect of improving the surface layer quality can be seen as compared with the case where it is not performed (condition 1), the improvement cost is not so large. Here, in order to improve the surface layer quality, bubbles and inclusions contained in the discharge flow are concentrated as much as possible without concentrating on a part of the region in the mold width direction (for example, the center in the width direction or the end in the width direction). It is thought that it is important to float while being distributed almost uniformly so as to be diluted. Considering such circumstances, the reason why the effect of improving the surface layer quality was not effectively obtained under the condition 9 is that, under the condition 9, a strong discharge flow is generated due to the fact that the braking force by the electromagnetic brake device does not substantially work in the vicinity of the discharge hole. This is considered to be because the amount of improvement in the surface layer quality is small because the bubbles and inclusions are concentrated on the end in the mold width direction in the direction of the short side.

  Furthermore, in Condition 9, although the internal quality is improved as compared with the case where no magnetic field is applied (Condition 1), the improvement effect is limited as compared with Condition 6-8. In Condition 9, since the magnetic field is hardly applied to the area around the immersion nozzle, the generation of the MHD counterflow can be suppressed, but the braking force by the electromagnetic brake device does not substantially work in the vicinity of the discharge hole. Since the flow velocity of the discharge flow cannot be reduced, and the momentum of the downward flow generated when the discharge flow collides with the short side surface of the mold cannot be sufficiently reduced, the number of bubbles and inclusions brought into the interior increases. It is thought that.

  On the other hand, when the absolute value of the magnetic flux density of the magnetic field by the second electromagnetic coil is appropriately adjusted as in condition 8, it can be seen that both the surface layer quality and the internal quality of the slab are improved. This is because desirable control of the flow of molten steel in the mold can be achieved by appropriately adjusting the distribution of the magnetic flux density in the mold width direction so that the flow speed of the MHD counterflow can be lowered while the flow speed of the downflow can be lowered. This is considered to be realized. Specifically, the reason why the surface layer quality is improved in condition 8 is that when a magnetic field having a magnetic flux density of about 0.1 T is applied to the central portion in the mold width direction as in condition 8, the discharge flow is By moderately attenuating, the separation and rising of bubbles and inclusions in the vicinity of the discharge hole are promoted, and the MHD counterflow is weak, so that these bubbles and inclusions are prevented from rising excessively. It is believed that there is. In addition, the reason why the quality is improved under condition 8 is that the discharge flow is moderately attenuated as described above, so that the flow velocity of the downward flow generated when the discharge flow collides with the mold short side surface is reduced. This is thought to be because of this.

(3. Supplement)
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1 Molten steel 10, 20, 60 Electromagnetic brake device 111, 211, 611 Iron core member (core member)
113, 213 First electromagnetic coil 115, 215 Second electromagnetic coil 117, 219 First power source 119, 221 Second power source 120 Mold 121 Long side mold plate 123 Short side mold plate 125 Back plate (Long side back plate)
127 Back plate (Short side back plate)
130 Immersion nozzle 131 Discharge hole 223 Third power source 217 Third electromagnetic coil 613 Electromagnetic coil 617 Power source

Claims (4)

An immersion nozzle that supplies molten metal is installed on the outer side of the long side of the continuous casting mold installed at the approximate center in the mold width direction, and a magnetic field in the mold thickness direction is applied to the molten metal in the mold. An electromagnetic brake device that
Installed so that the center in the height direction of the iron core is positioned below a pair of discharge holes of the immersion nozzle provided facing both short side surfaces of the mold, and against the molten metal in the mold A global magnetic field application electromagnetic coil that applies a substantially uniform magnetic field over the entire area in the mold width direction;
A global magnetic field application power source for generating a magnetic field by the global magnetic field application electromagnetic coil by applying a current to the global magnetic field application electromagnetic coil;
A partial area magnetic field application electromagnetic coil configured to share a part of the iron core with the whole area magnetic field application electromagnetic coil and apply a substantially uniform magnetic field in a partial area in the mold width direction to the molten metal in the mold; ,
A partial area magnetic field application power source for generating a magnetic field by the partial area magnetic field application electromagnetic coil by applying a current to the partial area magnetic field application electromagnetic coil;
With
The distribution in the mold width direction of the magnetic flux density of the magnetic field applied by the whole area magnetic field applying electromagnetic coil and the partial area magnetic field applying electromagnetic coil is the same as the magnetic flux density in a predetermined area including the center in the mold width direction. The partial region magnetic field application electromagnetic coil is arranged so that the distribution can be smaller than the density,
Electromagnetic brake device. The partial region magnetic field application electromagnetic coil is installed in the predetermined region including the center in the mold width direction,
The electromagnetic brake device according to claim 1. 3. The electromagnetic brake device according to claim 1, wherein the global magnetic field application power source and the partial region magnetic field application power source are independently driven, and the global magnetic field application electromagnetic coil and the partial region magnetic field application electromagnetic wave are driven independently. Continuous casting is performed while controlling the distribution in the mold width direction of the magnetic flux density of the magnetic field applied by the coil.
Continuous casting method. The partial region magnetic field application electromagnetic coil is installed in the predetermined region including the center in the mold width direction,
By generating a magnetic field that cancels out the magnetic field generated by the whole-area magnetic field applying electromagnetic coil by the partial region magnetic field applying electromagnetic coil, the magnetic flux density of the magnetic field in the predetermined region is smaller than the magnetic flux density of the magnetic field in the other region. In continuous condition, perform continuous casting.
The continuous casting method according to claim 3.

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