JP2000202588A - Twin roll continuous casting method and apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a twin roll continuous casting method and an apparatus thereof, with which the pushing control of a side weir can be executed in response to the displacement of the end surfaces of cooling rolls during executing the casting. SOLUTION: A relational expression is beforehand obtained from many preceded casting heats and the temperature of cooling water for cooling the inner part of the cooling roll 1 at the flow-in side and the flow-out side is measured continuously during executing the actual casting. As the other way, the displacement of the rotating shaft of the cooling roll 1 is measured and this measured value is used and the displacement of the end surface of the cooling roll 1 is estimated from the above relational expression, and based on this estimated value, one side or both of the pushing force and the pushing speed of the side weir 3 are controlled. Further, as the other way, the displacement of the end surface of the cooling roll is measured continuously during executing the actual casting, and based on this measured value, one side or both of the pushing force and the pushing speed of the side weir are controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin-drum continuous casting method and apparatus, and more particularly, to a side dam pressing control so as to always maintain a good seal between a cooling drum end face and a side dam during casting. The present invention relates to a twin-drum continuous casting method and apparatus.

[0002]

2. Description of the Related Art Conventionally, a mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotating shafts horizontal and parallel to each other, and a pair of side dams pressed against both end surfaces of the cooling drum. A pair of solidified shells was grown on the surfaces of both rotating cooling drums, while a molten metal was continuously injected into the inside to form a pool, and these solidified shells were combined.
A twin-drum continuous casting technique for feeding a strip of slab downward from the mold is known. This continuous casting technology is particularly useful for continuous casting of thin slabs having a thickness of several mm, and is a very useful technology that enables a process of performing cold rolling directly from slabs without going through hot rolling. is there.

[0003] In twin-drum continuous casting, a side weir is brought into close contact with the end surface of a cooling drum to prevent hot water from leaking out of the pool and to perform a good sealing effect by the side weir so that the side edge of the slab has a desired shape. It is necessary to maintain it all the time. To this end, it is necessary to keep the end face of the cooling drum and the seal face of the side weir in an appropriate crimped state at all times during the execution of casting.

Japanese Patent Application Laid-Open No. 4-228243 discloses a technique for detecting a displacement of a side weir during casting, determining a direction of displacement of the side weir, and controlling a pressing mechanism of the side weir. This technology detects the retreating movement phenomenon of the side weir, corrects the pressing force of the side weir by jack operation, and immediately recovers to the preferable contact state before the retreat, preventing casting burrs and leakage of hot water. To enable stable casting for a long time.

In the above prior art, the responsiveness to the displacement of the side weir is remarkably improved by employing the jack operation, as compared with the pressing control of the side weir performed by the operation of the fluid pressure cylinder performed before that. However, the above prior art has room for improvement in the following points. During the execution of the casting, both end surfaces of the two cooling drums are displaced by the fluctuation of the cooling water temperature. Here, the displacement of the side weir detected by the above-described conventional technology is the displacement of the side weir, which is an integral rigid body that is simultaneously in contact with two adjacent cooling drum end faces, and is the displacement of the end face of each cooling drum. Does not correspond. As a result, when the two cooling drums undergo thermal expansion and contraction due to their respective water temperature changes and end face displacement occurs, correction of one or both of the side dam pressing force and the pressing speed corresponding thereto is insufficient. was there.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a twin-drum continuous casting method and apparatus capable of controlling the pressing of a side weir in response to displacement of a cooling drum end face during casting.

[0007]

To achieve the above object, the present invention provides the following twin-drum continuous casting method and apparatus. (1) A mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotation axes being horizontal and parallel to each other, and a pair of side weirs pressed against both end surfaces of these cooling drums. Are continuously injected to form a pool of water, a pair of solidified shells is grown on the surfaces of both rotating cooling drums, and a single strip-shaped slab in which these solidified shells are united is cast downward from the mold. In the twin-drum continuous casting method for sending out, for a number of pre-casting heats, at a plurality of times during the casting execution period, the temperature of the cooling water for cooling the inside of the cooling drum with water is controlled by the inflow port to the cooling drum and the cooling water from the cooling drum. Measured at the outflow port, and simultaneously measured the displacement of both end surfaces of the cooling drum with respect to the casting start time at the plurality of time points. With respect to a new casting heat, the temperature of the cooling water at both ports is continuously measured during the execution of casting, and the relationship between the cooling water and the new casting heat is obtained using the measured value. A twin-drum continuous casting method characterized by continuously estimating the displacement of both end surfaces of a cooling drum and controlling one or both of a pressing force and a pushing speed of the side weir based on the obtained estimated value.

(2) An apparatus for performing the method described in (1), wherein the thermometer continuously measures the temperature of the cooling water at both ports during casting, and measures the temperature at both ports. A computing device for calculating the displacement of both end faces of the cooling drum at the time of the above measurement at the time of the measurement based on the cooling water temperature, and pressing the side weir on the basis of the calculated displacement of the both end faces of the cooling drum. A twin-drum continuous casting apparatus, comprising: a control device for controlling one or both of a force and a pushing speed.

(3) A mold is composed of a pair of cooling drums arranged at predetermined intervals with their rotation axes being horizontal and parallel to each other, and a pair of side dams pressed against both end surfaces of the cooling drum. A pair of solidified shells is grown on the surfaces of both rotating cooling drums while continuously pouring a molten metal into the pool and forming a pool. In the twin-drum continuous casting method in which the casting drum is sent downward from a plurality of casting heats, the displacement of the shaft end of the rotating shaft of the cooling drum is measured at a plurality of times during the casting execution period, and the casting is simultaneously performed at the plurality of times. The displacement of both ends of the cooling drum with respect to the start time is measured, and the relational expression between the displacement of the shaft end of the rotating shaft and the displacement of both ends of the cooling drum is obtained in advance, and a new casting heat is obtained. About During the execution of casting, the displacement of the shaft end of the rotating shaft was continuously measured, and the displacement of both end faces of the cooling drum was continuously estimated by the above-mentioned relational expression using the obtained measured values, and the obtained values were obtained. A twin-drum continuous casting method comprising controlling one or both of a pressing force and a pushing speed of the side weir based on the estimated value.

(4) An apparatus for performing the method according to (3), wherein the displacement meter measures the displacement of the shaft end of the rotating shaft continuously during casting, and the measured axis of the rotating shaft. A computing device that calculates the displacement of both ends of the cooling drum at the time of the measurement based on the displacement of the end by the above relational expression, and the pressing force of the side weir based on the calculated displacement of the both ends of the cooling drum And a control device for controlling one or both of the indentation speed.

(5) A mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotation axes being horizontal and parallel to each other, and a pair of side dams pressed against both end surfaces of the cooling drum. A pair of solidified shells is grown on the surfaces of both rotating cooling drums while continuously pouring a molten metal into the pool and forming a pool. In the twin-drum continuous casting method of sending out from below, during the execution of casting, continuously measure the displacement of both end surfaces of the cooling drum, and based on the obtained measurement values, one or both of the pressing force and the pushing speed of the side weir. , And a twin-drum continuous casting method.

(6) An apparatus for performing the method according to (5), wherein a displacement meter for continuously measuring displacement of both end faces of the cooling drum during casting, and the measured cooling drum A twin-drum continuous casting apparatus, comprising: a control device for controlling one or both of a pressing force and a pressing speed of the side weir based on displacement of both end faces.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a twin-drum continuous casting apparatus to which the present invention is applied has rotating shafts 2 and 2 arranged horizontally and parallel to each other at a predetermined interval T. Pair of cooling drums 1, 1 and a pair of side dams 3, pressed against both end surfaces 5, 5 of these cooling drums 1, 1.
3, a casting mold is formed, and while a molten metal is continuously poured into the casting mold to form a pool 6, a pair of cooling drums 1, 1 rotating on each other in the direction of the arrow are provided on a pair of surfaces S, S. The solidified shells 7, 7 are grown, and a single strip-shaped slab 8 in which the solidified shells 7, 7 are united is sent downward from the mold.

FIG. 3 shows a side view of one of the cooling drums 1 as viewed from the side. The rotating shaft 2 protruding from both end surfaces 5 of the cooling drum 1 has one end supported by a fixed bearing F and the other end supported by a movable bearing L. Thereby, when the drum 1 and the shaft 2 thermally expand due to heat input from the molten metal during casting, the drum 1 and the shaft 2 can be displaced in the axial direction toward the movable bearing L. Further, one of the two drums can be aligned with the end faces of the drums before the start of casting by the position adjusting mechanism 9 between the fixed bearing F and the pedestal 4F.

According to the present invention, in the cooling drum having such a shaft supporting structure, it is possible to control the pressing of the side dam during the execution of casting according to the following principle. First, in the first invention, when the temperature of the cooling drum changes, thermal expansion or contraction occurs. At the same time, the temperature of the cooling water passing through the cooling drum also changes, and side dam pressing control is performed. The temperature of the cooling drum changes depending on the temperature of the molten metal and the elapsed time after the start of casting. The temperature of the cooling water on the outflow side from the cooling drum rises with respect to the temperature of the cooling water on the inflow side to the cooling drum.

The relationship between the inflow and outflow temperatures of the cooling water and the displacement of the end face of the cooling drum due to thermal expansion and contraction is accumulated for a large number of precedent casting heats, and this relationship is used as a relational expression. The displacement of the end face of the cooling drum can be estimated by continuously measuring the temperature of the cooling water by using. One or both of the pressing force and the pushing speed of the side weir can be controlled based on the estimated value.

It is often difficult to measure the displacement of the end face of the cooling drum during casting. On the other hand, the cooling water temperature can be easily and continuously measured during the execution of casting. This is a great advantage of the first invention. Next, in the second invention, the displacement of the rotating shaft end accompanying the thermal expansion and contraction of the cooling drum is measured, the displacement of the cooling drum end face is estimated from the shaft end displacement, and the pressing force of the side weir is determined based on the estimated value. And / or pushing speed.

Also in this case, the correspondence between the shaft end displacement and the displacement of the cooling drum end face is accumulated for a large number of preceding casting heats, and this relation is used as a relational expression in a new casting heat to make the above estimation. The displacement of the rotating shaft end during casting is difficult to measure compared to the cooling water temperature, but it can be measured relatively easily than the displacement of the cooling drum end surface. It is an advantage that the correspondence is good.

Finally, in the third invention, the displacement of the end face of the cooling drum is measured during the casting. As described above, this measurement is the most difficult, but has an advantage that the displacement of the end face of the cooling drum can be directly used to control the pressing of the side weir. Normally, the side dam pressing control based on the cooling water temperature of the first invention is performed. If necessary, control is performed based on the rotation shaft end displacement of the second invention or the cooling drum end surface displacement of the third invention. Two or more of the three types of control may be combined as appropriate.

[0020]

Embodiment 1 FIG. 4 shows a basic configuration example of a control system according to the first invention. The cooling water flows from an inflow port (W1) that opens at one shaft end of the rotating shaft 2 protruding from both end surfaces 5 of the cooling drum 1 and passes through the inside of the cooling drum 1 and the other shaft end of the rotating shaft 2 Flows out of the outflow port that opens to the side (W2). Each side weir 3 is pressed against the cooling drum end face 5 by a plurality of pressing devices P (for example, stepping cylinders).

During the execution of the casting, the temperatures of the inflow water W1 and the outflow water W2 are continuously measured by thermometers T1 and T2, respectively, and are input to the arithmetic unit 10 as electric signals. The arithmetic unit 10 has a built-in storage device that stores a relational expression between the inflow water temperature, the outflow water temperature, and the displacement of the end face 5.
The estimated value of the end face displacement is calculated instantaneously based on the input from T2. The calculated end face displacement value (estimated value) is
Is sent to the control device 20 from the controller. The control device 20 instructs one or both of the necessary pressing force and the pressing speed of each of the plurality of pressing devices P based on the end surface displacement value. Each pressing device P that receives the command presses the side weir 3 against the end face 5 of the cooling drum 1 with one or both of the necessary pressing force and pressing speed.

Embodiment 2 FIG. 5 shows an example of the basic configuration of a control system according to the second invention. The flow of the cooling water is not shown. During the casting, the displacement of the shaft end of the rotary shaft 2 on the movable bearing L side shown in FIG. 3 is continuously measured by the displacement meter D and is input to the arithmetic unit 10 as an electric signal. Arithmetic unit 10
Has a built-in storage device in which a relational expression between the shaft end displacement and the displacement of the end face 5 of the cooling drum 1 is recorded, and calculates an estimated value of the end face displacement instantaneously based on the input from the displacement meter D. The calculated end face displacement value (estimated value) is sent from the arithmetic unit 10 to the control unit 20. The control device 20 instructs one or both of the necessary pressing force and the pressing speed of each of the plurality of pressing devices P based on the end surface displacement value. Each pressing device P receiving the command presses the side weir 3 against the end face 5 of the cooling drum 1 with one or both of the necessary pressing force and pressing speed.

[Embodiment 3] FIG. 6 shows a basic configuration example of a control system according to the third invention. The flow of the cooling water is not shown. During the execution of the casting, the displacement of the both end faces 5 of the cooling drum 1 is continuously measured by the displacement meter D and sent to the control device 20 as an electric signal. The control device 20 instructs one or both of the necessary pressing force and the pressing speed of each of the plurality of pressing devices P based on the end surface displacement value. Each pressing device P that receives the command presses the side weir 3 against the end face 5 of the cooling drum 1 with one or both of the necessary pressing force and pressing speed.

[0024]

As described above, according to the present invention,
Provided is a twin-drum continuous casting method and apparatus capable of performing pressing control of a side weir in response to displacement of a cooling drum end surface during casting.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a twin-drum continuous casting apparatus.

FIG. 2 is a cross-sectional view near the center of the entire length of the drum in FIG.

FIG. 3 is a layout diagram showing a cooling drum supporting mechanism of a twin drum continuous casting apparatus to which the method of the present invention is applied.

FIG. 4 shows a configuration example of a side weir control system according to the first invention.

FIG. 5 shows a configuration example of a side weir control system according to the second invention.

FIG. 6 shows a configuration example of a side weir control system according to a third invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cooling drum 2 ... Rotating shaft 3 ... Side weir 5 ... End face of cooling drum 1 ... Pud pool 7 ... Solidified shell 8 ... Strip-shaped slab 9 ... Position adjusting mechanism 10 ... Computing device 20 ... Control device Surface W1: cooling water flowing into cooling drum 1 W2: cooling water flowing out from cooling drum 1 L: movable bearing F: fixed bearing T1, T2: thermometer D: displacement gauge P: pressing device

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Izaki 3434 Shimada, Hikari-shi, Yamaguchi Prefecture Nippon Steel Corporation Hikari Works F-term (reference) 4E004 DA13 RA08 SC01 SC07

Claims (6)

[Claims] 1. A mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotation axes being horizontal and parallel to each other, and a pair of side dams pressed against both end surfaces of the cooling drum. A pair of solidified shells is grown on the surfaces of both rotating cooling drums while continuously pouring the molten metal to form a pool, and a single strip-shaped slab combining these solidified shells is removed from the mold. In the twin-drum continuous casting method of feeding downward, for a number of pre-casting heats, at a plurality of points during the casting execution period, the temperature of the cooling water for cooling the inside of the cooling drum with water is set to the inflow port to the cooling drum and the cooling drum. At the same time, the displacement of both end faces of the cooling drum with respect to the casting start time is measured at the plurality of times, and the cooling water temperature of both ports and the cooling drum temperature are measured. A relational expression with the displacement of the end face is obtained in advance, and for a new casting heat, the temperature of the cooling water at both the ports is continuously measured during the execution of the casting, and the relational expression is obtained using the obtained measurement value. Wherein the displacement of both end faces of the cooling drum is continuously estimated, and one or both of the pressing force and the pushing speed of the side weir are controlled based on the obtained estimated value. 2. An apparatus for performing the method of claim 1, wherein the thermometer measures the temperature of the cooling water at both ports continuously during the execution of casting, and the cooling measured at both ports. Based on the water temperature, by the relational expression, a computing device that calculates the displacement of both end surfaces of the cooling drum at the time of the measurement, and the pressing force of the side weir based on the calculated displacement of the both end surfaces of the cooling drum. A twin-drum continuous casting apparatus, comprising: a control device for controlling one or both of the pushing speeds. 3. A mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotation axes being horizontal and parallel to each other, and a pair of side weirs pressed against both end surfaces of these cooling drums. A pair of solidified shells is grown on the surfaces of both rotating cooling drums while continuously pouring the molten metal to form a pool, and a single strip-shaped slab combining these solidified shells is removed from the mold. In the twin-drum continuous casting method of sending downward, for a number of preceding casting heats, the displacement of the shaft end of the rotating shaft of the cooling drum is measured at a plurality of times during a casting execution period, and casting is started at the plurality of times at the same time. The displacement of both ends of the cooling drum with respect to the time point is measured, and the relational expression between the displacement of the shaft end of the rotating shaft and the displacement of both ends of the cooling drum is obtained in advance, and for a new casting heat, , The displacement of the shaft end of the rotating shaft is continuously measured during the execution of the fabrication, and the displacement of both end faces of the cooling drum is continuously estimated by the above-mentioned relational expression using the obtained measurement value, and the obtained estimation is obtained. A twin-drum continuous casting method comprising controlling one or both of a pressing force and a pressing speed of the side weir based on the value. 4. An apparatus for performing the method according to claim 3, wherein the displacement meter measures a displacement of a shaft end of the rotating shaft continuously during casting, and the measured shaft end of the rotating shaft. Based on the displacement, the computing device that calculates the displacement of both ends of the cooling drum at the time of the measurement by the above relational expression, and the pressing force of the side weir based on the calculated displacement of both ends of the cooling drum. A control device for controlling one or both of the pushing speeds,
A twin-drum continuous casting apparatus comprising: 5. A mold is constituted by a pair of cooling drums arranged at predetermined intervals with their rotation axes horizontal and parallel to each other, and a pair of side dams pressed against both end surfaces of these cooling drums. A pair of solidified shells is grown on the surfaces of both rotating cooling drums while continuously pouring the molten metal to form a pool, and a single strip-shaped slab combining these solidified shells is removed from the mold. In the twin-drum continuous casting method of feeding downward, the displacement of both end faces of the cooling drum is continuously measured during casting, and one or both of the pressing force and the pushing speed of the side weir are determined based on the obtained measurement values. A twin-drum continuous casting method characterized by controlling. 6. An apparatus for performing the method according to claim 5, wherein a displacement meter for continuously measuring the displacement of both end faces of the cooling drum during casting, and the measured both end faces of the cooling drum. And a control device for controlling one or both of the pressing force and the pressing speed of the side weir based on the displacement of the twin weir.