JP2010188375A - Casting mold equipment for continuous casting of metal and continuous casting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form traveling waves of vibration along a casting direction on an inner wall surface of a casting mold copper plate even in large equipment such as casting mold equipment of a real continuous casting machine when continuously casting molten metal such as molten steel, and consequently to secure lubrication property between a solidified shell and the inner wall surface of the casting mold copper plate, to prevent seizure and sticking of the solidified shell and the inner wall surface of the casting mold, and to stably continuously cast them without causing cracks, breakout of a casting piece surface. <P>SOLUTION: The casting mold equipment for continuous casting of metal is the casting mold equipment 1 for continuous casting which forms a rectangular casting space with two pairs of casting mold copper plates 2, 3. A plurality of actuators 4 are arranged for deforming the inner wall surface of the casting mold copper plate in a direction orthogonal to a casting piece pulling out direction. The casting mold equipment is constituted to propagate displacement of deformation at the inner wall surface of the casting mold copper plate formed by the actuator in the casting piece pulling out direction or in the opposite direction thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mold equipment for continuous casting of metal and a continuous casting method, and more particularly, so that a volume change between a solidified shell and an inner wall surface of a mold copper plate propagates in a slab drawing direction or the opposite direction. The present invention relates to a continuous casting mold facility in which a cyclic deformation is formed in a direction orthogonal to a slab drawing direction on an inner wall surface of a mold copper plate on the contact surface side with a solidified shell, and a continuous casting method using this mold It is about.

  When continuously casting a molten metal such as molten steel, it cools in contact with the inner wall surface of the mold copper plate (hereinafter also simply referred to as “mold inner wall surface”), and the resulting solidified shell and mold inner wall surface are seized or stuck. In order to stably cast continuously without causing surface cracks or breakouts in the slab, the mold is sine-waved and other waveforms with a vibration stroke of several to tens of millimeters in the slab drawing direction. A reciprocating motion is made along the reciprocating motion (this reciprocating motion is called “oscillation”), and a lubricant is continuously or intermittently supplied to the inner wall surface of the mold. In the case of molten steel, mold powder made of oxide, carbonate, fluoride, etc. is added onto the molten steel surface in the mold, and the molten mold powder is melted by the heat of the molten steel between the mold inner wall surface and the solidified shell. It is used as a lubricant. Breakout is a phenomenon in which unsolidified molten metal flows out due to breakage or cracking of the solidified shell, and the vibration stroke is the width between the upper limit and the lower limit of the reciprocating motion, that is, twice the amplitude.

  In addition, in order to further improve the breakout and slab surface properties, a technique for controlling the inflow amount of mold powder by applying ultrasonic vibration or high frequency vibration has been reported. For example, Patent Document 1 discloses a method of continuously casting a plurality of ultrasonic vibrators by vibrating a mold inner wall surface in the vicinity of a molten metal surface at a frequency of several kHz. , A method of continuously casting the mold in a direction orthogonal to the drawing direction of the slab by high-frequency vibration having an amplitude of 10 to 500 μm and a frequency of 1000 to 10000 cpm is disclosed. In a mold composed of two pairs of mold copper plates, a pair of molds corresponding to the vibration cycle of the mold oscillation while applying high frequency vibration to the pair of mold copper plates while oscillating the entire mold in the direction of drawing the slab. A method of continuous casting by vibrating a copper plate in the horizontal direction is disclosed.

  Furthermore, in Patent Documents 4 and 5, vibrators are installed at the upper and lower parts of the mold so that vibrations propagating in the direction of drawing the slab are formed on the inner wall surface of the mold, and applied at the upper part. A technique has been disclosed in which the vibration energy absorbed by the lower portion is formed, and a traveling wave of vibration is formed on the inner wall surface of the mold to ensure lubricity.

JP-A-1-122645 JP-A-3-210942 JP-A-5-76997 Japanese Patent Laid-Open No. 62-9750 JP 2002-321044 A

  However, the above prior art has the following problems.

  The technology disclosed in Patent Documents 1 to 3, which vibrates the entire mold copper plate with ultrasonic waves of the same phase, when the mold is vibrated only by ultrasonic vibration, the frequency is large, but the amplitude is small, Almost no effect on burn-in or breakout, but when used in combination with a conventional sine waveform or other waveform, the mold oscillates only with a conventional sine waveform or other waveform. Compared to the case, a reasonable effect can be obtained. However, it is not possible to obtain the effect that is appropriate for the equipment modification, that is, the expected effect.

  On the other hand, in the techniques disclosed in Patent Documents 4 to 5 for forming a traveling wave of vibration on the inner wall surface of the mold, the mold powder is forcibly transferred together with the traveling wave, and the inflow amount of the mold powder increases. The desired effect can be obtained. In particular, when the mold is oscillated with a waveform such as a conventional sine waveform, a sufficient effect is exhibited. However, in the techniques disclosed in Patent Documents 4 to 5, the mechanical and electrical characteristics of the upper and lower pair of vibrators and the vibration characteristics of the mold are strictly matched, and then the control of the vibrator is calculated in advance. Accurate driving in the ultrasonic region is required. Therefore, it must be said that it is extremely difficult to realize the above technique with a large facility such as a mold facility of an actual continuous casting machine.

  The present invention has been made in view of such circumstances, and the object of the present invention is a large facility such as a mold facility of an actual continuous casting machine when continuously casting a molten metal such as molten steel. In addition, a traveling wave of vibration along the casting direction can be formed on the inner wall surface of the mold copper plate. As a result, lubricity between the solidified shell and the inner wall surface of the mold copper plate is ensured, and It is intended to provide a continuous casting mold facility and a continuous casting method capable of preventing continuous seizure and sticking, and stably and continuously casting without causing cracks or breakouts on the surface of a slab.

  A metal casting equipment for continuous casting according to a first aspect of the present invention for solving the above problems is a casting equipment for continuous casting in which a rectangular casting space is formed by two pairs of casting copper plates, and the inner wall surface of the casting copper plate. A plurality of actuators for deforming the steel plate in a direction perpendicular to the slab drawing direction are arranged, and the displacement of the deformation on the inner wall surface of the mold copper plate formed by the actuator is directed toward the slab drawing direction or the opposite direction. It is configured to propagate.

  The mold equipment for continuous casting of metal according to the second invention is the casting equipment for continuous casting of the metal according to the first invention, wherein the actuator periodically operates at 0.1 Hz to 500 Hz, and the phases of the actuators positioned in order of the slab drawing direction are , Being sequentially advanced or sequentially delayed.

  According to a third aspect of the present invention, in the metal casting equipment for continuous casting according to the first or second aspect, the operating direction of the actuator is a direction perpendicular to the slab drawing direction, and one end of the actuator is the mold copper plate It is characterized by being connected to.

  According to a fourth aspect of the present invention, in the metal casting equipment for continuous casting according to the first or second aspect, the operating direction of the actuator is a direction parallel to the slab drawing direction, and both ends of the actuator are the mold. It is characterized by being connected to a copper plate.

  According to a fifth aspect of the present invention, in the metal casting equipment for continuous casting according to any one of the first to fourth aspects, the actuator comprises a hydraulic cylinder or a piezoelectric element.

  According to a sixth aspect of the present invention, there is provided a continuous casting method for a metal using the casting equipment for continuous casting according to any one of the first to fifth aspects, wherein the inner wall surface of the casting copper plate is formed in the direction of drawing a slab by the actuator. The molten metal is injected into the casting space while being deformed in an orthogonal direction.

  According to a seventh aspect of the present invention, there is provided a metal continuous casting method according to the sixth aspect, further comprising oscillating the mold equipment for continuous casting with a sinusoidal waveform or a biased sinusoidal waveform.

  According to the present invention, when continuously casting a molten metal such as molten steel, seizure and sticking between the solidified shell and the inner wall surface of the mold copper plate are prevented, and the slab is stable without causing surface cracks or breakouts. As a result, a significant reduction in manufacturing costs can be achieved, resulting in an industrially beneficial effect.

1 is a schematic side sectional view of a continuous casting mold facility according to the present invention as viewed from a direction of a mold short side copper plate. 1 is a schematic side sectional view of a continuous casting mold facility according to the present invention as viewed from the direction of a long mold copper plate. It is a plane schematic diagram of the mold equipment for continuous casting concerning the present invention. It is a schematic diagram of the deformation | transformation condition of a mold long side copper plate with progress of time when the phase of an actuator is advanced in order of a slab drawing direction. It is the schematic which shows an example which makes the operation direction of an actuator a direction parallel to a slab drawing direction.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 are schematic views of a continuous casting mold facility according to the present invention, FIG. 1 is a schematic side sectional view seen from the direction of the mold short side copper plate, and FIG. 2 is from the direction of the mold long side copper plate. FIG. 3 is a schematic side sectional view, and FIG. 3 is a schematic plan view.

  1 to 3, reference numeral 1 is a casting equipment for continuous casting, 2 is a long copper plate of the mold copper plate, 3 is a short copper plate of the mold copper plate, 4 is an actuator, 5 is a fixed base, and 6 is a fixed base. An immersion nozzle, 7 is a discharge hole, 8 is molten steel, 9 is a solidified shell, 10 is a mold powder, and a continuous casting mold facility 1 includes a pair of opposed long mold copper plates 2 and a pair of opposed short mold sides. The rectangular casting space is formed by a total of two pairs of mold copper plates. The mold short side copper plate 3 is sandwiched between the mold long side copper plates 2, and the width of the cast slab can be changed by changing the sandwiched position. The mold long-side copper plate 2 and the mold short-side copper plate 3 can reciprocate along the slab drawing direction with a normal mold oscillation, that is, with a vibration stroke of several mm to several tens of mm (= twice the amplitude). Further, the mold long side copper plate 2 and the mold short side copper plate 3 have a water cooling structure cooled by cooling water.

  As the mold oscillation waveform, it is optimal to adopt a sine waveform or a biased sine waveform that is normally used. Here, the biased sine waveform means that the time taken for the maximum displacement when the mold is raised during one cycle of mold vibration with respect to the sine waveform is shifted to the latter half of the case of the sine waveform, and the mold is lowered. The time taken for the maximum displacement of the hour is a waveform that is shifted to the first half compared to the case of the sine waveform.

  On the back side of the mold long side copper plate 2 and the mold short side copper plate 3, one end is connected to the mold long side copper plate 2 or the mold short side copper plate 3, and the other end is fixed to the continuous casting mold facility 1. An actuator 4 connected to the solid mount 5 is installed. A plurality of actuators 4 are arranged in the width direction of the mold long side copper plate 2 and the mold short side copper plate 3 and the slab drawing direction. In this case, in the slab drawing direction, the long-side copper plate 2 and the short-side copper plate 3 are arranged side by side at the same position in the width direction. 1 to 3, the number of actuators 4 is four in the casting direction, four in the mold long side copper plate 2 and two in the mold short side copper plate 3 in the width direction. It is shown and is not limited to FIGS.

  By operating the actuator 4 in a direction orthogonal to the slab extraction direction, that is, by operating the actuator 4 so that the shaft 4a of the actuator 4 extends and contracts in a direction orthogonal to the slab extraction direction, Since one end is solidified by the fixed mount 5, the long mold copper plate 2 and the short mold copper plate 3 vibrate in a direction perpendicular to the slab drawing direction according to the operation of the actuator 4. Deform. The upper limit of the deformation amplitude of the long-side copper plate 2 and the short-side copper plate 3 may be about 50 μm because the thickness of the mold powder 10 in the gap between the mold copper plate and the solidified shell is generally about 200 μm.

  The continuous casting mold facility 1 according to the present invention is configured such that the displacement of deformation on the inner wall surfaces of the long mold copper plate 2 and the short mold copper plate 3 propagates in the slab drawing direction or in the opposite direction. ing. During continuous casting, if the long mold copper plate 2 and the short mold copper plate 3 are deformed so as to vibrate in the direction perpendicular to the slab drawing direction, the volume of the gap between the long mold copper plate 2 and the solidified shell 9 and the short mold The volume of the gap between the side copper plate 3 and the solidified shell 9 changes. Here, “the displacement of deformation on the inner wall surface of the mold long side copper plate 2 and the mold short side copper plate 3 propagates in the direction of drawing the slab or the opposite direction” means that “the volume change is the slab. This means the same as “propagating in the pulling direction or vice versa”. As will be described later, the progress direction of the volume change is opposite to the progress direction of the deformation displacement.

  That is, the continuous casting mold facility 1 according to the present invention is configured such that traveling waves of vibration are formed on the inner wall surfaces of the long mold copper plate 2 and the short mold copper plate 3. The formation of the traveling traveling wave on the inner wall surface causes the actuators 4 arranged in the slab drawing direction to operate at the same frequency, and the phase of each actuator 4 is advanced or delayed in the order of the slab drawing direction. Can be obtained.

  Here, the phase is advanced in the order of the slab drawing direction as follows. That is, when the actuator 4 is operated in a sine waveform, the displacement of the tip of the shaft 4a is expressed by a general expression Asin (2πft + α) (where A is the amplitude, f is the frequency, and t is the time). Is done. At time t, the displacement of the uppermost actuator 4 in the slab drawing direction is Asin (2πft), the displacement of the actuator 4 immediately below it is Asin (2πft-β), and the displacement of the actuator 4 directly below is Asin To reduce the phase by a predetermined value (here, β) in order of the slab drawing direction so as to be (2πft-2β) is referred to as advancing the phase. Delaying the phase in the order of the slab drawing direction means conversely increasing the phase by a predetermined value in the order of the slab drawing direction.

  FIG. 4 is a schematic diagram of the deformation state of the long-side copper plate 2 over time when the actuator 4 is operated in a sine waveform and the phase of the actuator 4 arranged in the slab drawing direction is advanced in the order of the slab drawing direction. The figure is shown. Time passes from the left to the right in FIG. 4, that is, in the direction of the arrow.

  As shown in FIG. 4, the gap between the long mold copper plate 2 and the solidified shell 9 is filled with molten mold powder 10 which is added onto the molten steel in the mold and melted. By operating the actuator 4, the volume of the gap between the long copper plate 2 and the solidified shell 9 changes. When the phase of the actuator 4 is advanced in the order of the slab drawing direction, the deformation displacement formed on the inner wall surface of the long copper plate 2 of the mold advances in the direction from the downstream side to the upstream side in the slab drawing direction. That is, the traveling wave of vibration travels in the direction from the downstream side to the upstream side in the slab drawing direction. Thereby, the volume change of the gap between the mold long-side copper plate 2 and the solidified shell 9 advances in the direction from the upstream side to the downstream side in the slab drawing direction. In FIG. 4, the change in the volume of the gap is indicated by ●. The mold powder 10 is also transferred by the change in volume of the gap from the upstream side to the downstream side in the slab drawing direction. In order to supplement the transferred mold powder 10, the flow of the mold powder 10 into the gap between the long mold copper plate 2 and the solidified shell 9 is promoted, and the mold powder into the gap between the long mold copper plate 2 and the solidified shell 9 is promoted. 10 inflow increases.

  That is, when the inflow amount of the mold powder 10 is insufficient due to the characteristics of the mold powder 10 to be used, the inflow amount of the mold powder 10 is ensured by advancing the phase of the actuator 4 in order of the slab drawing direction, resulting in poor lubrication. The resulting burn-in and breakout are prevented. On the other hand, when the inflow amount of the mold powder 10 is excessive due to the characteristics of the mold powder 10 to be used, the inflow amount of the mold powder 10 is suppressed by delaying the phase of the actuator 4 in the order of the slab drawing direction. An appropriate amount of inflow is achieved, non-uniform cooling in the mold is prevented, and slab vertical cracks are reduced. In the actuators 4 arranged in the width direction of the mold long side copper plate 2 and the mold short side copper plate 3, the phase may be made the same at the same height position in the slab drawing direction.

  The frequency of the actuator 4 is 0.1 to 500 Hz, preferably 10 Hz to 50 Hz. If the frequency is less than 0.1 Hz, the traveling speed of the vibration traveling wave formed on the inner wall surface of the mold copper plate is slow, and the effect to be expressed is small. On the other hand, if the frequency exceeds 500 Hz, the effect is saturated, Equipment costs are wasted.

  The actuator 4 shown in FIGS. 1 to 4 is constituted by a hydraulic cylinder, but a piezoelectric element is also suitable as the actuator 4. Since the piezoelectric element undergoes a volume change when a voltage is applied, the volume change is used to deform the mold copper plate. Since the heat resistance temperature of the piezoelectric element is 200 to 300 ° C., it can be sufficiently used on the back surface of the mold.

  If the installation interval of the actuator 4 is too wide, the mold copper plate cannot be sufficiently deformed. Therefore, the installation interval of the actuator 4 is preferably several mm to several tens mm. Further, if the mold powder 10 existing in the gap between the mold copper plate and the solidified shell 9 is solidified, the effect of mold powder transfer is reduced. Therefore, it is not necessary to dispose the actuator 4 to the lower part of the mold. What is necessary is just to arrange | position to about the center part of the extraction | drawer direction of a casting_mold | template. Further, since the inflow amount of the mold powder 10 is generally larger in the mold short side copper plate 3 than in the mold long side copper plate 2, the actuator 4 may be disposed only on the mold long side copper plate 2.

  Hereinafter, a continuous casting method of the molten steel 8 using the continuous casting mold equipment 1 according to the present invention configured as described above will be described.

  The molten steel 8 staying in a tundish (not shown) is passed through a submerged nozzle 6 installed at the bottom of the tundish from a discharge hole 7 provided in the lower part of the submerged nozzle 6, and a pair of mold long side copper plates 2 and a pair It is poured into a rectangular casting space formed by the mold short-side copper plate 3. At that time, depending on the characteristics of the mold powder 10 to be used, the deformation displacement formed on the inner wall surfaces of the mold long side copper plate 2 and the mold short side copper plate 3 is directed from the downstream side to the upstream side in the slab drawing direction. The actuator 4 is operated so as to travel in the direction or the opposite direction. Mold powder 10 is added on the molten steel 8 in the mold. In this case, since the seizure and sticking of the solidified shell 9 are further prevented by using the conventional mold oscillation together, it is possible to oscillate the entire continuous casting mold equipment 1 along the slab drawing direction. preferable.

  The molten steel 8 injected into the casting space comes into contact with the inner wall surfaces of the long mold copper plate 2 and the short mold copper plate 3 and is cooled, and the solidified shell 9 is formed along the inner wall surfaces of the long mold copper plate 2 and the short mold copper plate 3. Form. The solidified shell 9 is continuously drawn to the lower side of the continuous casting mold facility 1 by a pinch roll (not shown) provided below the continuous casting mold facility 1 to continuously cast the molten steel 8.

  By continuously casting the molten steel 8 in this manner, seizure and sticking between the solidified shell 9 and the inner wall surfaces of the long-side copper plate 2 and the short-side copper plate 3 can be prevented, and surface cracks and breakouts can be caused on the slab. Stable continuous casting can be achieved without generating it.

  In addition, although the actuator 4 shown in FIGS. 1-4 is a direction where the operation direction of the actuator 4 is orthogonal to a slab drawing direction, it can also be set as a direction parallel to a slab drawing direction as shown in FIG. . FIG. 5 is a schematic view showing an example in which the operating direction of the actuator 4 is parallel to the slab drawing direction, and both ends of the shaft 4 a of the actuator 4 are connected to the long-side copper plate 2 of the mold.

DESCRIPTION OF SYMBOLS 1 Mold equipment for continuous casting 2 Mold long side copper plate 3 Mold short side copper plate 4 Actuator 5 Fixed mount 6 Immersion nozzle 7 Discharge hole 8 Molten steel 9 Solidified shell 10 Mold powder

Claims (7)

  A casting apparatus for continuous casting that forms a rectangular casting space with two pairs of mold copper plates, wherein a plurality of actuators for deforming the inner wall surface of the mold copper plate in a direction perpendicular to the slab drawing direction are arranged, A mold equipment for continuous casting of metal, characterized in that the deformation displacement on the inner wall surface of the mold copper plate formed by the actuator propagates in the slab drawing direction or in the opposite direction.   2. The actuator according to claim 1, wherein the actuator periodically operates at 0.1 Hz to 500 Hz, and the phases of the actuators positioned in the order of the slab drawing direction are sequentially advanced or sequentially delayed. The mold equipment for continuous casting of the metal described.   3. The continuous metal according to claim 1, wherein an operation direction of the actuator is a direction orthogonal to a slab drawing direction, and one end of the actuator is connected to the mold copper plate. Casting mold equipment.   The operating direction of the actuator is a direction parallel to the slab drawing direction, and both end portions of the actuator are connected to the mold copper plate. Mold equipment for continuous casting.   The metal casting apparatus for continuous casting according to any one of claims 1 to 4, wherein the actuator comprises a hydraulic cylinder or a piezoelectric element.   A molten metal is formed in the casting space using the continuous casting mold equipment according to any one of claims 1 to 5 while the inner wall surface of the mold copper plate is deformed in a direction perpendicular to the slab drawing direction by the actuator. A continuous casting method for a metal, characterized by injecting a metal.   The metal continuous casting method according to claim 6, further comprising oscillating the continuous casting mold equipment with a sine waveform or a biased sine waveform.

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