JP5074269B2 - Electromagnetic stirring mold for continuous casting - Google Patents

Description

The present invention relates to an electromagnetic stirring mold for continuous casting having a cooling box that accommodates an electromagnetic coil in a vertically movable manner.

In continuous casting of steel, an electromagnetic stirrer is installed in the long-side cooling box of the mold to stir the molten steel injected into the mold, and lift and remove non-metallic inclusions and gas contained in the molten steel. . At this time, it has been found that when the upper end of the core provided in the electromagnetic coil of the electromagnetic stirring device is made to coincide with the meniscus position, the meniscus portion is stirred most uniformly and strongly.

On the other hand, when the molten steel is poured from the tundish into the mold using the immersion nozzle, if the meniscus position is constant, the wear of the part corresponding to the meniscus position of the immersion nozzle becomes intense, and the wear rate of this part is immersed. Nozzle life is limited. Then, in order to replace the immersion nozzle that has reached the end of its life, casting must be temporarily stopped, resulting in a problem that complicated operations increase. For this reason, the position of the immersion nozzle corresponding to the meniscus position is changed intentionally (that is, the part where wear occurs in the immersion nozzle is not concentrated in one place) It is necessary to take measures to extend the service life.

Therefore, in Patent Document 1, the entire linear motor type electromagnetic stirring device whose setting position is variable in the vertical direction is housed in the long-side cooling box, and the electromagnetic coil is accommodated in the long-side cooling box according to the variation of the meniscus height. It is described that it moves up and down. However, if you try to store the entire electromagnetic stirring device, the size of the long-side cooling box will increase, and the large-sized long-side cooling box will be used in a place where there is a lot of interference with various devices around the mold such as tundish, columns, and electrical wiring. There is a problem in that it is not easy to secure a space for installing. Furthermore, when the electromagnetic stirrer is stored in the long-side cooling box, there is a problem that the maintainability of the electromagnetic stirrer is deteriorated.

Therefore, in Patent Document 2, a mounting flange is provided on the electromagnetic coil, and the mounting flange is sewn to the long-side cooling box with a bolt, and the sewing position of the mounting flange is adjusted according to the variation of the meniscus height. Thus, it is described that the electromagnetic coil moves up and down in the long-side cooling box. However, in the method of sewing the mounting flange to the long cooling box with bolts, the fluctuation of the meniscus position is detected by the mold level sensor, and the electromagnetic coil is moved up and down so that the upper end of the core of the electromagnetic coil always coincides with the meniscus position. You cannot operate while moving. For this reason, in Patent Document 3, an electromagnetic coil is installed in a long-side cooling box so as to be movable up and down, and a mold level sensor for measuring the meniscus position is provided, and the electromagnetic coil is moved up and down based on an output signal from the mold level sensor. It is described that it is adjusted so that the upper end of the core of the electromagnetic coil always coincides with the meniscus position.

JP 63-60056 A JP 2002-321040 A JP 2007-196285 A

By the way, since the long side copper plate of the mold is in direct contact with the molten steel having a temperature of about 1500 ° C. during continuous casting, the surface temperature is about 200 to 400 ° C., the back surface temperature is about 100 ° C., and the thickness direction of the long side copper plate is A large temperature difference occurs, and a large thermal deformation occurs in the long side copper plate. In order to suppress this thermal deformation, the long side copper plate is firmly fixed to the long side cooling box, and the long side cooling box must have high rigidity in order to suppress the thermal deformation of the long side copper plate. However, in the invention described in Patent Document 3, an opening is formed on the surface facing the long side copper plate mounting surface in the long side cooling box so that the electromagnetic coil accommodated in the long side cooling box can move up and down. Therefore, the rigidity of the long side cooling box is reduced. For this reason, even if the long-side copper plate is fixed to the long-side cooling box, the thermal deformation of the long-side copper plate during casting cannot be suppressed. The problem that occurs occurs. Furthermore, the long-side copper plate is easily thermally deformed, resulting in a problem that the life of the long-side copper plate is shortened and maintenance costs are increased.

The present invention has been made in view of such circumstances, and the electromagnetic coil of the electromagnetic stirring device is accommodated in the mold cooling box so as to be movable up and down, and the meniscus position of the molten steel is changed to prevent local wear of the immersion nozzle. An object of the present invention is to provide an electromagnetic stirring mold for continuous casting that can uniformly stir the meniscus portion and can increase the rigidity of the cooling box to suppress the deformation of the cooling wall (mold copper plate). And

The electromagnetic stirring mold for continuous casting according to the present invention that meets the above-mentioned object is provided with a cooling wall in contact with the molten steel on the front surface, a supply chamber for supplying cooling water to a cooling water groove provided in the cooling wall, and the cooling chamber A cooling box having a drainage chamber for discharging cooling water from the water groove and a storage chamber in which an electromagnetic stirrer is movably mounted in the vertical direction; An electromagnetic stirring mold for continuous casting provided with an opening into which the apparatus is inserted,
A flange mounting means is provided at an edge of the opening, and the electromagnetic stirring device is attached to the flange mounting means via a mounting flange provided in the electromagnetic stirring device, and the flange mounting means is the mounting flange. And a mounting flange insertion portion for holding the mounting flange so as to be movable up and down. When the electromagnetic stirring device moves up and down, the mounting flange is guided by the flange mounting means. While moving up and down with the electromagnetic stirring device.

In the electromagnetic stirring mold for continuous casting according to the present invention, the supply chamber and the drainage chamber can be provided below the storage chamber.

In the electromagnetic stirring mold for continuous casting according to the present invention, since the electromagnetic stirring device is installed in the storage chamber so as to be movable up and down, even if the meniscus position of the molten steel is changed to prevent local wear of the immersion nozzle, the electromagnetic stirring device The upper end of the core provided in the electromagnetic coil of the stirring device can be moved so as to always coincide with the meniscus position, and the meniscus portion can be uniformly stirred. As a result, while preventing local wear of the immersion nozzle, the non-metallic inclusions and gas contained in the molten steel can be lifted and removed to improve the quality of the slab.

Further, the opening is provided with a flange mounting means, and the flange mounting means is provided with a mounting flange provided in the electromagnetic stirrer. Even if it is going to be deformed, since the mounting flange is inserted into the flange insertion portion of the flange mounting means, it is possible to prevent the storage chamber and hence the cooling box from being greatly deformed. As a result, it is possible to suppress large thermal deformation during casting of the cooling wall fixed to the cooling box. Thereby, while being able to prevent the quality deterioration of the slab accompanying the thermal deformation of a cooling wall, a cooling wall becomes long life and a maintenance cost can be reduced.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a side sectional view of an electromagnetic stirring mold for continuous casting according to an embodiment of the present invention, FIG. 2 is a partially cutaway rear view of a cooling box of the mold, and FIG. 3 is a cooling box of the mold. FIG. 4 is an explanatory view showing a state of thermal deformation obtained by numerical calculation when the mounting flange is removed from the mold and a comparative mold as a comparative example.

As shown in FIGS. 1 to 3, a continuous casting electromagnetic stirring mold 10 according to an embodiment of the present invention has a pair of long side copper plates 12 and 13 as an example of a cooling wall in contact with molten steel 11 on the front surface. And supply chambers 14 and 15 for supplying cooling water to cooling water grooves (not shown) provided on the long side copper plates 12 and 13, respectively, and drain chambers 16 and 17 for discharging cooling water from the cooling water grooves, respectively. The long side cooling box 24, which is an example of a cooling box provided with storage chambers 22 and 23 in which the electromagnetic stirring device 18 is inserted from the openings 20 and 21 provided on the back side and is movably mounted in the vertical direction, 25. The level (meniscus position) of the molten steel 11 injected into the continuous casting electromagnetic stirring mold 10 is a non-contact type molten steel level meter 26 (for example, an eddy current sensor) disposed above the continuous casting electromagnetic stirring mold 10. ). This will be described in detail below.

The drain chambers 16 and 17 are connected to the upper portions of the supply chambers 14 and 15, and the storage chambers 22 and 23 are connected to the upper portions of the drain chambers 16 and 17. Long-side copper plates 12 and 13 are respectively provided on the front surfaces (surfaces on the molten steel 11 side) of the long-side cooling boxes 24 and 25 configured by the supply chambers 14 and 15, the drain chambers 16 and 17, and the storage chambers 22 and 23. The storage chambers 22 and 23 protrude from the back surfaces of the supply chambers 14 and 15 and the drainage chambers 16 and 17 to the back side (the side opposite to the molten steel 11, that is, the rear side). As shown in FIGS. 2 and 3, mounting members 37 and 38 for fixing the electromagnetic stirring mold 10 for continuous casting to a continuous casting facility (not shown) are provided on both sides in the width direction of the long-side cooling boxes 24 and 25, respectively. It has been.

Flange mounting means 27 are provided at the edges of the openings 20 and 21 formed on the back sides of the storage chambers 22 and 23, respectively. The electromagnetic stirring device 18 includes an electromagnetic coil 19, a terminal board (not shown) provided on the back side of the electromagnetic coil 19 and connected to a power cable for supplying current to the electromagnetic coil 19, and a box shape that houses the terminal board. The casing 28 is provided. As shown in FIG. 1, the front end portion of the core 29 provided in the electromagnetic coil 19 protrudes from the front surface of the electromagnetic stirring device 18, and the electromagnetic stirring device 18 is flanged at a position on the back side of the electromagnetic coil 19. A mounting flange 30 is provided which is attached to the means 27.

The flange mounting means 27 has a mounting flange insertion portion 31 that fits the outer peripheral portion of the mounting flange 30 and guides and holds the mounting flange 30 in the vertical direction. Here, the attachment flange insertion portion 31 is fastened to, for example, the flange receiving member 32 attached to the edge of the opening 20, the gap adjusting member 33 standing on the outer peripheral side of the flange receiving member 32, and the gap adjusting member 33. It has a space formed by a flange pressing member 35 attached so as to be parallel to the flange receiving member 32 using a bolt 34 which is an example of a member.

As shown in FIGS. 1 to 3, when the gap adjusting member 33 is erected on the outer peripheral side of the flange receiving member 32, the inner distance L ₂ in the vertical direction of the gap adjusting member 33 is the vertical direction of the mounting flange 30. than the width L ₁ of the set variation large meniscus position. For example, L ₂ −L ₁ = 100 mm. In addition, the inner distance L ₃ in the left-right direction of the gap adjusting member 33 substantially matches the width in the left-right direction of the mounting flange 30. Further, the height H of the gap adjusting member 33 (that is, the width of the gap between the flange receiving member 32 and the flange pressing member 35) is 0 when the thickness of the mounting flange 30 is T. Or it forms so that it may become a value which exceeds 0 and is smaller than the thermal deformation amount of the long side cooling boxes 24 and 25. For example, HT = 0.03 mm. Here, the amount of thermal deformation of the long-side cooling boxes 24 and 25 can be obtained by numerical calculation or actual measurement.

Accordingly, the electromagnetic stirring device 18 is inserted from the openings 20 and 21 with the core 29 on the front side, and the fluid pressure cylinder 36 which is an example of the vertical drive means provided on both sides in the width direction of the electromagnetic stirring device 18 is accommodated in the storage chamber 22. , 23, and when the flange pressing member 35 is fixed to the surface of the gap adjusting member 33 by bringing the mounting flange 30 into contact with the flange receiving member 32, the flange insertion portions 31 are provided at the edges of the openings 20, 21. The flange attachment means 27 is configured, and the outer peripheral portion of the attachment flange 30 is inserted into the attachment flange insertion portion 31.

In the mounting flange 30 in a state of being inserted into the mounting flange insertion portion 31, if gaps are formed above and below the mounting flange 30, the outer peripheral portion of the mounting flange 30 and the mounting flange insertion portion 31 are formed. Since a gap of, for example, 0.03 mm is formed between the side surfaces, when the fluid pressure cylinder 36 is operated to move the electromagnetic stirring device 18 up and down in the storage chambers 22 and 23, the mounting flange 30 is The outer peripheral portion can be moved up and down while being fitted into the mounting flange insertion portion 31 while being guided by the mounting flange insertion portion 31.

Then, the effect | action of the electromagnetic stirring mold 10 for continuous casting which concerns on one embodiment of this invention is demonstrated.
As shown in FIG. 1, in the storage chambers 22 and 23 in which the electromagnetic stirring device 18 is installed, openings 20 and 21 are formed on the back side thereof, and a part of the electromagnetic stirring device 18 is outside the storage chambers 22 and 23. Since it protrudes, the volume of the casing 28 accommodated in the storage chambers 22 and 23 can be reduced, the storage chambers 22 and 23 can be downsized, and the shape of the long-side cooling boxes 24 and 25 can also be downsized. . As a result, it is possible to prevent interference between various devices of the continuous casting equipment and the electromagnetic stirring mold 10 for continuous casting, and the long side cooling boxes 24 and 25 can be easily installed.

Further, the outer peripheral portion of the mounting flange 30 attached to the casing 28 is fitted into a mounting flange insertion portion 31 of the flange mounting means 27 provided in the openings 20 and 21. Then, as shown in FIGS. 2, 3, in the space portion of the mounting flange fitting portion 31 the outer peripheral portion of the mounting flange 30 is fitted, the inner width L ₂ in the vertical direction of the space portion is vertical mounting flange 30 The inner width L _{3 in} the left-right direction is, for example, 100 mm larger than the width L ₁ and substantially matches the width in the left-right direction of the mounting flange 30. Further, the width of the space (that is, the width of the gap between the flange receiving member 32 and the flange pressing member 35) is formed to be 0.03 mm larger than the thickness T of the mounting flange 30, for example.

For this reason, when the fluid pressure cylinder 36 is operated to move the casing 28 up and down in the storage chambers 22 and 23, the mounting flange 30 is fitted into the mounting flange with the outer peripheral portion fitted into the mounting flange insertion portion 31. It can move up and down while being guided by the portion 31. Therefore, the level (meniscus position) of the molten steel 11 injected into the continuous casting electromagnetic stirring mold 10 is detected by the molten steel level meter 26 disposed above the continuous casting electromagnetic stirring mold 10, and the fluid pressure cylinder 36 is detected. By operating and moving the casing 28 up and down, the upper end of the core 29 provided in the electromagnetic coil 19 of the electromagnetic stirring device 18 and the meniscus position can be matched.

The openings 20 and 21 are provided with a flange mounting means 27 having a mounting flange fitting portion 31, and a mounting flange 30 is mounted on the flange mounting means 27. For this reason, a large temperature difference occurs between the front and back surfaces of the long side copper plates 12 and 13 during casting, the long side copper plates 12 and 13 are thermally deformed, and the long side copper plates are long due to the influence of the thermal deformation of 12 and 13. Even if the storage chambers 22 and 23 of the side cooling boxes 24 and 25 are about to deform, a gap (for example, 0.03 mm) that is a difference between the width of the space portion of the mounting flange insertion portion 31 and the thickness T of the mounting flange 30 disappears. At this time, the mounting flange 30 and the flange mounting means 27 interfere with each other, and the storage chambers 22 and 23, and thus the long-side cooling boxes 24 and 25 are prevented from being greatly deformed. As a result, it is possible to prevent the long side copper plates 12 and 13 from being further thermally deformed via the long side cooling boxes 24 and 25.

Here, in the electromagnetic stirring mold 10 for continuous casting, the width of the long side copper plates 12 and 13 in the left-right direction is 2100 mm, the width in the vertical direction is 900 mm, and the thickness is 30 mm. When a temperature difference of 0 ° C. is generated, thermal deformation of the upper ends of the long-side cooling boxes 24 and 25 when the gap, which is the difference between the height H of the gap adjusting member 33 and the thickness T of the mounting flange 30, is 0 mm. Was obtained by numerical calculation (FIG. 4). Note that the thermal deformation is in the thickness direction of the long side copper plates 12 and 13, and FIG. 4 shows a state in which the upper end portions of the long side cooling boxes 24 and 25 change along the left or right direction from the center. ing. As shown in FIG. 4, the thermal deformation tends to increase with increasing distance from the center of the upper ends of the long-side cooling boxes 24 and 25, and the difference in thermal deformation between the ends and the center of the upper ends of the long-side cooling boxes 24 and 25. Is 0.23 mm. If a gap, for example, 0.03 mm, which is the difference between the height H of the gap adjusting member and the thickness T of the mounting flange 30 is added to the amount of deformation, the amount of thermal deformation is 0.26 mm.

Further, as a comparative example, the thermal deformation of the upper end portion of the long side cooling box to which the flange mounting means 27 and the mounting flange 30 are not mounted was obtained by numerical calculation. At the upper end of the long side cooling box, the thermal deformation tends to increase as the distance from the center increases, and the difference in thermal deformation between the end of the upper end of the long side cooling box and the center is 0.37 mm. Therefore, by attaching the mounting flange 30 to the flange mounting means 27, the thermal deformation of the upper ends of the long side cooling boxes 24 and 25 is reduced to about 70% compared to the case where the flange mounting means and the mounting flange are not mounted. It was confirmed that it was possible.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.

It is a sectional side view of the electromagnetic stirring mold for continuous casting which concerns on one embodiment of this invention. It is a partially cutaway rear view of the cooling box of the same mold. It is a partially notched top view of the cooling box of the same mold. It is explanatory drawing which shows the state of the thermal deformation calculated | required by the numerical calculation at the time of removing the flange for attachment from the same mold and the same mold as a comparative example.

Explanation of symbols

10: Electromagnetic stirring mold for continuous casting, 11: Molten steel, 12, 13: Long side copper plate, 14, 15: Supply chamber, 16, 17: Drainage chamber, 18: Electromagnetic stirring device, 19: Electromagnetic coil, 20, 21: Openings, 22, 23: storage chamber, 24, 25: long side cooling box, 26: molten steel level meter, 27: flange mounting means, 28: casing, 29: core, 30: mounting flange, 31: mounting flange insertion Part, 32: flange receiving member, 33: gap adjusting member, 34: bolt, 35: flange pressing member, 36: fluid pressure cylinder, 37, 38: mounting member

Claims (2)

A cooling wall in contact with the molten steel is attached to the front surface, a supply chamber for supplying cooling water to a cooling water groove provided in the cooling wall, a drainage chamber for discharging cooling water from the cooling water groove, and an electromagnetic stirring device Has a cooling box provided with a storage chamber that is movably mounted in the vertical direction, and is provided with an electromagnetic stirring for continuous casting provided with an opening into which the electromagnetic stirring device is inserted on the back side of the storage chamber. A mold,
A flange mounting means is provided at an edge of the opening, and the electromagnetic stirring device is attached to the flange mounting means via a mounting flange provided in the electromagnetic stirring device, and the flange mounting means is the mounting flange. And a mounting flange insertion portion for holding the mounting flange so as to be movable up and down. When the electromagnetic stirring device moves up and down, the mounting flange is guided by the flange mounting means. An electromagnetic stirring mold for continuous casting, which moves in the vertical direction together with the electromagnetic stirring device. The electromagnetic stirring mold for continuous casting according to claim 1, wherein the supply chamber and the drainage chamber are provided below the storage chamber.

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