JPH0120942B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a horizontal continuous casting method.

In the prior art, the tundish nozzle and the mold must be fixed to each other in order to prevent molten metal from flowing out between the tundish nozzle made of a refractory material and the water-cooled mold. Therefore, the vicinity of the tundish nozzle adjacent to the water-cooled mold is cooled, and a solidified shell is formed at the molten metal contact area, which is fixed to the nozzle. Furthermore, since the molten metal enters the pores of the refractory material constituting the tundish nozzle and solidifies as it is, the adhesion force increases. Therefore, when the casting is pulled out, the solidified shell ruptures and a so-called breakout occurs.

In another prior art technique to solve this problem, a nonporous silicon nitride ring or boron nitride ring with excellent lubricity is hermetically connected between the tundish nozzle and the mold. These silicon nitride rings and boron nitride rings have a short casting life and are expensive. However, although the use of these materials has the effect of alleviating the sticking of the tundish nozzle and the solidifying shell, it is not possible to completely avoid the sticking of the mold tube and the solidifying shell.
As seen in 15332, intermittent extraction is forced.

Some prior art is shown in Utility Model Application No. 52-160615. In this prior art, in order to maintain airtightness between the tundish nozzle and the mold, an electromagnetic force that applies a restriction is generated toward the center of the cross section of the melt flow. In such prior art, gravity compensation of the melt flow is not performed, and therefore, the center of aperture of the melt flow at the boundary between the tundish nozzle and the mold does not coincide with the center of the mold. This makes it impossible to make the cross-sectional shape of the constricted portion of the melt flow substantially similar to the cross-sectional shape of the mold. Therefore, the shape of the cast body cannot be made into the desired shape, resulting in a decrease in quality.

Another prior art is disclosed in JP-A-53-76130, in which a coil is provided concentrically surrounding the slab between the tundish nozzle and the mold, and alternating current power is supplied to this coil. , creating a radially inwardly directed pressure to compensate for metal static pressure. In order to compensate for the gravity of this metal, an electrode 11 is immersed in the tundish, and a current is passed in the longitudinal direction of the molten metal to generate a magnetic field in the mold that is perpendicular to and horizontal to the axis of the mold. and exerts an upward force on the molten metal inside the mold.

In such prior art, although gravity compensation is performed within the mold, it is impossible to make the pressure acting on the molten metal mold uniform in the circumferential direction, and therefore the mold has a precise cross-sectional shape. It is not possible to obtain a cast body.

An object of the present invention is to provide a horizontal continuous casting method that allows continuous drawing and that allows obtaining a cast body having an accurate mold cross-sectional shape.

In the first invention, the vicinity of the boundary between the tundish nozzle and the mold is surrounded by a coil, and the coil is arranged such that the axis of the coil is eccentric above the axis of the tundish nozzle and the mold. the coil is energized by alternating current power, thereby exerting a greater radially inward electromagnetic force on the lower part of the molten metal than on the upper part, and the current that excites the coil has a rate of change over time. This is a horizontal continuous casting method characterized by having a waveform that is small when the current increases and becomes large when the current decreases.

Further, the second invention of the present invention provides a plurality of electromagnetic field generating elements configured by winding a coil around a rod-shaped core extending in the axial direction of the tundish nozzle and the mold in the circumferential direction. The coils are energized by alternating current power, and these electromagnetic field generating elements are arranged more closely at the bottom of the molten metal than at the top, thereby causing a greater radial inward force at the bottom of the molten metal than at the top. This horizontal continuous casting method is characterized in that the current that excites the coil by applying an electromagnetic force to the coil has a waveform whose time rate of change is small when the current increases and becomes large when the current decreases.

Furthermore, in the third invention, the vicinity of the boundary between the tundish nozzle and the mold is surrounded by a coil, and the coil has a length in the axial direction between the tundish nozzle and the mold at the lower part than the upper part. is made small, the coil wires are made dense, and the coil is excited with alternating current power, thereby
The current which applies a larger radially inward electromagnetic force to the lower part of the molten metal than the upper part, and which excites the coil, has a waveform whose time rate of change is small when the current increases and becomes large when the current decreases. This is a horizontal continuous casting method.

Further, the fourth invention of the present invention provides a plurality of electromagnetic field generating elements configured by winding a coil around a rod-shaped coil extending in the axial direction of the tundish nozzle and the mold at equal intervals in the circumferential direction. The coils are energized by alternating current power to supply a larger current to the lower coil than to the upper coil, thereby creating a larger radially inward electromagnetic force in the lower part of the molten metal than in the upper part. This horizontal continuous casting method is characterized in that the current that applies a force and excites the coil has a waveform whose time rate of change is small when the current increases and becomes large when the current decreases.

According to the first to fourth inventions of the present invention, a coil is arranged near the boundary between the tundish nozzle and the mold, and this coil is excited by AC power, so the molten metal is squeezed and the solidified shell is This prevents the particles from sticking to the tundish nozzle and also prevents the tundish nozzle from being worn out.

In the first invention, the coil surrounds the vicinity of the boundary between the tundish nozzle and the mold, and is arranged such that the axis of the coil is eccentric above the axis of the tundish nozzle and the mold. The lower part of the molten metal is subjected to a greater radially inward electromagnetic force than the upper part.

Further, in the second invention, the electromagnetic field generating elements are arranged more densely in the lower part than in the upper part of the molten metal,
This also creates a greater radially inward electromagnetic force in the lower part of the molten metal than in the upper part.

Further, in the third invention, the coil wires of the coil surrounding the vicinity of the boundary between the tundish nozzle and the mold are denser in the lower part than in the upper part, so that the length in the axial direction between the tundish nozzle and the mold is made smaller. This also allows a greater radially inward electromagnetic force to be exerted on the lower part of the molten metal than on the upper part.

Furthermore, according to the fourth aspect of the present invention, a larger current is supplied to the lower coils than to the upper coils of the electromagnetic field generating elements arranged at equal intervals in the circumferential direction in the vicinity of the boundary between the tundish nozzle and the mold. This also makes it possible to generate a larger magnetic flux density at the bottom of the molten metal than at the top. In this way, gravity compensation of the reduced diameter molten metal is ensured.

Furthermore, according to the first to fourth aspects of the present invention, when the excitation current that applies a negative squeezing force to the molten metal decreases, the time rate of change during the current decrease is increased. The induced current generated by the current with a large rate of change over time is caused by the molten metal and nearby conductive members (for example, the coil 3 described later).
5 bobbin 35', tundish nozzle fitting 13, mold wall, etc.). Therefore, the negative squeezing force acting on the molten metal can be suppressed as much as possible. In this way, by taking the time average of one cycle of the electromagnetic current, it becomes possible to apply a squeezing force to the molten metal.

FIG. 1 is an overall system diagram of an embodiment of the present invention. In this horizontal continuous casting equipment, a tundish 1 is provided with a heating device 2 for stabilizing the temperature of molten steel within the tundish 1. The cast body 4 from the mold 3 is pulled out from the cooling zone 5 by a drawing device 6 and cut by a cutting device 7 to obtain an ingot 9. This ingot 9 is conveyed by a roller table 10.

FIG. 2 is an enlarged sectional view of the vicinity of the mold 3. The tundish 1 is lined with a refractory material 11 and stores molten metal 12. A tundish nozzle 14 made of a refractory material is fixed to the tundish 1 by a mounting hardware 13. The mold 3 has a cooling liquid passage 15, and a steel mold tube 33 is liquid-cooled.
The channel 16 for the cast body 4 of this mold 3 is coaxially continuous with the tundish nozzle 14 . This mold 3 is fixed to a tundish nozzle 14. Near the boundary 17 between the tundish nozzle 14 and the mold 3, an electromagnetic field generating means 18 is provided which is comprised of a coil surrounding the boundary 17 and is energized by alternating current power. Due to the electromagnetic field of the electromagnetic field generating means 18, the molten steel passing near the boundary 17 is reduced in diameter and squeezed inward in the radial direction for reasons described below in connection with FIG. Therefore, near the boundary 17, molten steel is prevented from coming into contact with the portion of the tundish nozzle 14 closer to the mold 3. Therefore, the solidified shell is prevented from sticking to the tundish nozzle 14, and the cast body 4 can be continuously pulled out.

The electromagnetic field generating means 18 includes a first coil 34 surrounding the vicinity of the boundary 17 and a second coil 35. The coil wires of both the coils 34 and 35 are wound around the tundish nozzle 14 and a portion of the mold 3 with an interval in the radial direction.

Referring to FIG. 3, when an excitation current flows through the coil wire of second coil 35 in the direction of arrow 36, a magnetic field is generated in the direction of arrow 37. When the exciting current increases along the curve 61 in FIG. 3A, an eddy current flows in the molten metal 12 in the direction of the arrow 38, which is opposite to the exciting current of the arrow 36. According to Fleming's left hand rule, the molten metal 1
2 is acted upon by an electromagnetic force directed toward its center. On the other hand, if the exciting current decreases along the curve 62 of Figure 3a, the eddy currents 38 will be in the opposite direction and exert a spreading force on the molten steel. In order to suppress this force from acting on the molten steel as much as possible, the alternating current is generally a sine wave, but the excitation current waveform is distorted as shown in FIG. make it higher. With such an excitation waveform, it is possible to absorb the components in the area of curve 62 by making the bobbin 35' of the coil 35 or the tundish nozzle mounting bracket 13 in FIG. 2 made of copper or the like with low electrical resistivity. It is. As a result, when the time average of one cycle is taken, a drawing force acts on the molten steel as shown in FIG. 3a and 2.

Furthermore, in FIG. 3a, the excitation current is curve 6
In the region along lines 2 and 62', the molten steel flows in the opposite direction to the arrow 38 in FIG. 3, so a negative squeezing force acts on the surface of the molten steel. Curves 62, 6 with large changes in current value
The greater the change in the excitation current, the more easily the induced current in the region 2' is absorbed by the molten steel, the mold wall, etc. Therefore, by shortening the regions of the curves 62, 62' shown in FIG. 3A, the induced current absorbing plate 18' provided inside the electromagnetic field generating means 18 is unnecessary. The induced current absorbing plate 18' actively absorbs the induced current in the area of curves 62 and 62'.

In this way, the diameter of the molten steel 12 is reduced near the boundary 17. This also applies to the other first coil 34.

FIG. 4 shows the pressure distribution of the static pressure acting on the molten metal 12 passing through the tundish nozzle 14 and the mold 3, the static pressure compensating force acting on the molten steel surface by the first coil 34 and the second coil 35, and the diameter reduction. Shows force distribution. When the axis-perpendicular cross section of the tundish nozzle 14 and the mold 3 is rectangular, the molten metal 12 stored in the tundish 1 acts on the surface layer of the molten metal near the boundary with the tundish nozzle 14 and the mold 3. The static pressure distribution is shown by line a in FIG. Further, the distribution of the static pressure compensating force acting on the surface layer of the molten metal is shown by line b in FIG. 41. The first coil 34 is shown in FIG.
A magnetic force is generated to compensate for the static pressure shown by . The static pressure compensation force P1 in FIG. 42 is the sum of the pressure Pat acting on the upper surface of the surface layer of the molten steel and the diameter reduction force Pα. The axis of this first coil 34 coincides with the axes of the tundish nozzle 14 and the mold 3. Furthermore, this second coil 35 is used to compensate for the unbalanced static pressure shown in FIG.
The axis of the coil is eccentrically arranged above the axes of the tundish nozzle 14 and the mold 3. Therefore, in the molten metal 12 near the boundary 17, a larger magnetic flux density is generated in the lower part of the molten metal 12 than in the upper part.

The function of the second coil 35 will be explained with reference to FIG. FIG. 5 1 is a front view of the second coil 35 viewed from the axial direction, and FIG. 5 2 shows the distribution of magnetic flux density in a cross section AA passing through the axis 39. Referring to this drawing, as the second coil 35 deviates from the axis 39 in the radial direction, the second coil 35
It can be seen that the magnetic flux density within 5 becomes large. According to the present invention, the axis 39 of the second coil 35 is located above the axes of the tundish nozzle 14 and the mold 3, and therefore a large electromagnetic force acts on the lower part of the molten metal 12. Figure 4 2
An electromagnetic force that resists gravity, represented by , acts on the molten metal 12 to compensate for gravity.

The inner diameter of the casting passage 16 of the mold 3 is made smaller along the front of the drawing direction of the casting 4 in accordance with the amount of shrinkage of the casting as it solidifies in order to equalize cooling within the mold.

The means for supplying lubricant will be explained with reference to FIG. A ring-shaped header 41 is formed in the tundish nozzle 14. A nozzle 42 is formed in this header 41 so as to face inward in the radial direction of the tundish nozzle 14 . This header 41
A lubricant 46 is pumped through a conduit 43. The nozzle 42 is located at a position forward in the drawing direction 45 from a position 44 where the molten metal 12 leaves the tundish nozzle 14 . The lubricant 46 is CaO,
The main ingredients are powders of SiO ₂ and Al ₂ O ₃ , as well as pure iron,
It is made by mixing powder with good electrical conductivity such as Co. In the lubricant 46 mixed with powder having good electrical conductivity, the powder having good electrical conductivity is used in the tundish nozzle 14 and the coil 3.
An electromagnetic force directed inward in the radial direction acts, thereby ensuring that the lubricant 46 adheres to the entire outer peripheral surface of the reduced diameter molten metal 12. Therefore, the lubricity with the portion where the diameter-reduced molten metal 12 first comes into contact with the casting passageway 16 is improved. Lubricant 4
6 may be made of rapeseed oil as a main component, with powder of pure iron cobalt or the like mixed therein.

FIG. 6 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 7 is a simplified sectional view taken along the section line - in FIG. This embodiment is similar to the previous embodiment and corresponding parts are provided with the same reference numerals. It should be noted that the electromagnetic field generating means 18 includes a plurality of electromagnetic field generating elements 50 arranged in the circumferential direction, each having a coil 49 wound around a rod-shaped core 47 extending in the axial direction of the tundish nozzle 14 and the mold 3. It consists of The electromagnetic field generating elements 50 are arranged more densely below the molten metal 12 than above. Therefore, a large magnetic flux density is given to the lower part of the molten metal 12. When a current flows through the coil 49 in the direction of the arrow 51, an eddy current is generated in the molten metal 12 in the direction of the arrow 52.
The direction of the magnetic field generated by the electromagnetic field generating element 50 is indicated by reference numeral 53. In this way, an electromagnetic force directed radially inward is generated in the molten metal 12, and the diameter of the molten metal 12 is reduced.
The electromagnetic field generating element 50 is configured to generate a molten metal 1 as described above.
Since magnetic flux is applied more densely to the lower part of the molten metal 12 than to the upper part, the static pressure of the molten metal 12 is completely compensated.

In another embodiment of the present invention, a lubricant such as rapeseed oil is applied to a reduced diameter molten metal 1 as shown in FIG.
2 may be sprayed by a nozzle 55 onto the part where the molded body passage 16 first comes into contact. This nozzle 55 is formed in an annular shape along the circumferential direction within a gap 56 between the diameter-reduced molten metal 12 and the casting passage 16.

FIG. 8 is a sectional view corresponding to FIG. 7 of another embodiment of the present invention. In this embodiment, the electromagnetic field generating element 50 has multiple layers (for example, two layers in this embodiment).
It is located in The radially inner first layer electromagnetic field generating element is indicated by reference numeral 50a, and the radially outer electromagnetic field generating element is indicated by reference numeral 50b. First layer and second layer electromagnetic field generating elements 50a, 50b
are arranged at positions shifted in the circumferential direction.

FIG. 9 is a partially enlarged sectional view of the embodiment shown in FIG. 8. Because the positions of the first and second electromagnetic field generating elements 50a and 50b are shifted in the circumferential direction, the molten metal 12 does not have large irregularities in the circumferential direction and has a smooth surface. . Therefore, the lubricant 46 uniformly adheres to the outer peripheral surface of the molten metal 12 whose diameter has been reduced.

FIG. 10 is a sectional view showing the principle of a part of still another embodiment of the present invention. In this embodiment, the coil 54 includes a tundish nozzle 14 and a coil wire wound around the axis of the mold 3. This coil 54 is the coil 5
The length of the tundish nozzle 14 and the mold 3 in the axial direction is made smaller in the lower part than in the upper part of the coil, and the coil wires are densely arranged. Therefore, a larger magnetic flux density is applied to the lower part of the molten metal 12 than the upper part. Therefore, static pressure compensation of the molten metal 12 is achieved more reliably. In this embodiment, the second coil 35 is displaced with respect to the axes of the tundish nozzle 14 and the mold 3 and is arranged similarly to the previous embodiment.

FIG. 11 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 12 is a plan view thereof seen from above.
Parts corresponding to those in the embodiment described above are given the same reference numerals. It should be noted that the mold 3 is mounted on a cart 23 that is movable back and forth in the direction 45 in which the cast body 4 is pulled out. This truck 23 is biased by a spring 24 and is vibrated by being reciprocated back and forth in the direction 45 in which the cast body 4 is pulled out by an eccentric cam 26 driven by a motor 25. An electromagnetic field generating means 18 is also mounted on the trolley 23. Nozzle 42
By applying the lubricant 46 over the entire outer peripheral surface of the reduced diameter molten metal 12, lubrication is ensured and oxidation of the molten metal is also prevented.

In this embodiment, the mold 3 and the tundish nozzle 14 are arranged with a gap 28 between them, and the mold 3 is vibrated back and forth in the direction in which the cast body 4 is pulled out. This prevents it from sticking to the surface. Moreover, the cast body is quickly cooled. As a result, the cast body 4
Continuous drawing can be performed smoothly.
The tundish nozzle 14 has a large diameter at the front (right side in FIG. 11) in the drawing direction 45 of the cast body 4, so that even if the solidified shell is stuck to the tundish nozzle 14, it can be easily pulled out. It can be removed.

In another embodiment of the present invention, when a nozzle 55 shown in FIG. 6 is used in place of the nozzle 42, a flexible For example, the space between the mold 3 and the tundish nozzle 14 may be hermetically closed by a bellows-shaped airtight means 27. An inert gas such as argon or nitrogen can also be supplied into the airtight means 27 via a conduit 29.

FIG. 13 is a sectional view of still another embodiment of the present invention. In this embodiment, the tundish nozzle 14 is divided into a plurality of parts 14a and 14b and combined, making it easy to manufacture the tundish nozzle 14 having a large cross-section or a complicated cross-sectional shape. The rest of the structure is similar to the embodiment shown in FIGS. 1-12.

In the embodiment shown in FIGS. 11 to 13 described above, the electromagnetic field generating means 18 was mounted on the trolley 23 and vibrated integrally with the mold 3. However, as another embodiment of the present invention, the electromagnetic field generating means 18 may be provided at a fixed position. Furthermore, in the above embodiment,
Although the truck 23 is vibrated by the eccentric cam 26, it may be vibrated by a crank mechanism, a double-acting hydraulic cylinder, etc. in other embodiments of the present invention.

Furthermore, even if the present invention is applied to the conventional technology, as seen in Japanese Patent Publication No. 50-27448, in which a boron nitride ring or a silicon nitride ring is provided in the tundish nozzle part to perform intermittent drawing, the service life of these rings will be reduced. A sufficient effect can be obtained for extension. A similar effect can also be obtained by arranging coils as shown in FIG. 6 at equal intervals around the molten body and supplying a larger current to the lower coils than to the upper coils. In addition, as methods for lubricating the inside of the mold, there are two methods: supplying powder from near the start of the melt squeezing process as described above, and spraying lubricant at the point where the melt starts to make contact in the mold, as shown in Figure 6. However, the following method may also be used.

As shown in FIG. 6, the part where the reduced diameter molten metal 12 first comes into contact near the boundary 17 of the casting channel 16 of the mold 3 is made of highly lubricating and non-porous material such as boron nitride or silicon nitride. Protective layer 19 consisting of
is provided. A protective layer 20 made of carbon having excellent lubricity is formed downstream of the protective layer 19 in the cast body 4 . With this, mold 3
This prevents the solidified shell from sticking to the cast body passageway 16, making it easier to smoothly and continuously pull out the cast body 4.

By adjusting the magnetic field generating force of the electromagnetic field generating means 18 or moving the mounting position, it is possible to stop the molten metal 12 in the tundish 1 from flowing into the mold 3 from the tundish nozzle 14. In addition, in the embodiment shown in Fig. 2, more complete static pressure compensation is achieved by combining two coils, but even if only a cast body and an eccentric coil are used as a second coil 35, A similar effect can be obtained.

The invention can be broadly implemented for casting not only steel, but also any other electrically conductive molten metal.

As described above, according to the first to fourth inventions of the present invention, since the molten metal is squeezed near the boundary between the tundish nozzle and the mold, the molten metal does not come into contact with the tundish nozzle. This prevents the coagulation shell from sticking to the tundish nozzle, and also prevents the tundish nozzle from being worn out. Therefore, a horizontal continuous casting method capable of continuous drawing is realized.

Further, according to the first invention, the coil is arranged such that the axis of the coil is eccentric above the axis of the tundish nozzle and the mold, and according to the second invention, the electromagnetic field generating element is According to the third invention, the coil wires of the coil surrounding the vicinity of the boundary between the tundish nozzle and the mold are arranged more densely in the lower part than in the upper part, and in the tundish nozzle. Further, according to the fourth invention, the length of the lower coil of the electromagnetic field generating elements arranged at equal intervals in the circumferential direction is smaller than that of the upper coil. By supplying a large current, a larger magnetic flux density can be generated at the bottom of the molten metal than at the top.
Gravity compensation of the reduced diameter molten metal is reliably performed, and for this reason, it is possible to make the axis of the reduced diameter molten metal approximately coincide with the axis of the mold and guide it in a cross-sectional shape that is almost similar to the cross-sectional shape of the mold. It becomes possible. The quality of the cast body is therefore improved.

Moreover, in the prior art, a high degree of concentricity was required between the tundish, tundish nozzle, and mold in order to stably draw out the solidified shell, but according to the present invention, this requirement has been significantly eased. Ru.

In particular, in the first to fourth inventions of the present invention, the current that excites the coil has a waveform whose time rate of change is small when the current increases and becomes large when the current decreases, so that the negative squeezing force acting on the molten metal is reduced. It is possible to reduce it as much as possible. This makes it possible to efficiently squeeze the molten metal.

[Brief explanation of drawings]

FIG. 1 is an overall front view of an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of an embodiment of the present invention, and FIG. 3 is a perspective view for explaining the principle of reducing the diameter of molten metal 12. Fig. 3A is a diagram showing the relationship between exciting current and squeezing force, Fig. 4 is a cross-sectional view for explaining the force acting on the molten metal being reduced in diameter, and Fig. 5 is the function of the second coil 35. FIG. 6 is a longitudinal cross-sectional view of another embodiment of the present invention, FIG. 7 is a cross-sectional view taken from the cutting plane line of FIG. 6, and FIG. FIG. 9 is a sectional view corresponding to FIG. 7 of the embodiment, FIG. 9 is an enlarged sectional view of a part of FIG. 8, and FIG. 10 is a sectional view for explaining the principle of still another embodiment of the present invention. 11 is a longitudinal cross-sectional view of another embodiment of the present invention, FIG. 12 is a plan view of the illustrated embodiment, and FIG. 13 is a cross-sectional view of another embodiment of the present invention. be. DESCRIPTION OF SYMBOLS 1... Tundate dish, 3... Mold, 4... Cast body, 12... Molten metal, 14... Tundate nozzle, 16... Cast body passage, 18... Electromagnetic field generating means,
23...Dolly, 26...Eccentric cam, 33...Mold tube, 34...First coil, 35...Second coil,
42, 55... Nozzle, 46... Lubricant, 50... Electromagnetic field generating element.

Claims (1)

[Scope of Claims] 1. The vicinity of the boundary between the tundish nozzle and the mold is surrounded by a coil, and the coil is arranged such that the axis of the coil is eccentric above the axes of the tundish nozzle and the mold. , the coil is energized by alternating current power, thereby exerting a greater radially inward electromagnetic force on the lower part of the molten metal than on the upper part, and the current energizing the coil is
A horizontal continuous casting method characterized in that the time rate of change has a waveform that is small when the current increases and becomes large when the current decreases. 2 Near the boundary between the tandate nozzle and the mold, a rod-shaped core extending in the axial direction thereof,
An electromagnetic field generating element made up of a coil wound,
A plurality of electromagnetic field generating elements are arranged in the circumferential direction, and the coils are excited by AC power, and these electromagnetic field generating elements are arranged more densely in the lower part than in the upper part of the molten metal. A horizontal continuous casting method characterized in that the current that excites the coil by applying a larger radial inward electromagnetic force has a waveform whose time rate of change is small when the current increases and becomes large when the current decreases. 3. The vicinity of the boundary between the tundish nozzle and the mold is surrounded by a coil, and the length of the axial direction between the tundish nozzle and the mold is made smaller at the lower part than at the upper part, so that the coil element is The wires are packed together and the coil is energized by alternating current power, thereby exerting a greater radially inward electromagnetic force on the bottom of the molten metal than on the top, and the current energizing the coil is A horizontal continuous casting method characterized by having a waveform in which the time rate of change is small when the current increases and becomes large when the current decreases. 4. An electromagnetic field generating element configured by winding a coil around a rod-shaped coil extending in the axial direction of the nozzle and the mold is placed near the boundary between the tandate nozzle and the mold.
A plurality of coils are arranged at equal intervals in the circumferential direction, and the coils are excited with alternating current power, and a larger current is supplied to the lower coil than to the upper coil. The current that excites the coil by exerting a radially inward electromagnetic force is
A horizontal continuous casting method characterized in that the time rate of change has a waveform that is small when the current increases and becomes large when the current decreases.