JP5621390B2 - Cast roll shape control method and apparatus for twin roll type continuous casting apparatus - Google Patents

Description

  The present invention relates to a casting roll shape control method and apparatus for a twin roll type continuous casting apparatus.

  In general, a twin-roll continuous casting apparatus has a pair of cylindrical casting rolls disposed so as to be rotationally driven so as to extend in parallel at predetermined intervals in the horizontal direction, and to extend along the outer peripheral surface of the casting roll. And a cooling fluid supply means for supplying a cooling fluid to the cooling passage. The casting roll is driven to rotate while the cooling fluid is supplied to the cooling passage by the cooling fluid supply means. In the state, by supplying a molten metal at a high temperature (a temperature higher than the melting point of the metal supplied between the casting rolls, for example, about 1600 [° C.] in the case of low carbon steel) between the casting rolls, Solidified metal strip is continuously cast.

  In the twin-roll type continuous casting apparatus as described above, the amount of deformation of the casting roll during operation (hot) is predicted, and the shape of the casting roll matches the required thickness profile of the solidified metal strip. In contrast, cold crown processing is performed in advance (see FIG. 6).

  In addition, there exist patent document 1 and patent document 2 as what shows the general technical level relevant to the above twin roll type continuous casting apparatuses, for example.

  In Patent Document 1, the cooling fluid is circulated from the longitudinal central portion of the casting roll toward both ends, whereby the central portion of the casting roll swells and the thickness of the central portion of the solidified metal strip decreases. The point to prevent is disclosed.

  Further, in Patent Document 2, the casting roll is divided into three sections in the roll axis direction, and the cooling grooves in the two sections located at the end of the cooling grooves disposed near the roll surface are arranged in the same manner. The cooling groove of the section located at the center of the roll is configured to have a higher density than the cooling grooves of the two sections positioned at the end so as to increase the cooling capacity of the roll surface in the center. The point is disclosed.

JP-A-3-210944 JP-A-6-297108

As described above, the casting roll is provided with a crown in accordance with the required thickness profile of the solidified metal strip, but the inner peripheral surface side and the outer peripheral surface side in a state where the temperature is high due to a heat load during casting. The axial shape of the outer peripheral surface has a complicated shape due to the difference in thermal expansion due to the temperature difference between the two and the solid shape metal strip cast by the casting roll, especially in the vicinity of both end portions. As shown in FIG. 7, the plate thickness in the vicinity of both ends tends to deviate from the target plate thickness indicated by the phantom line, and is likely to be unstable.

  Instability of the plate thickness at both ends of the solidified metal strip itself becomes a quality problem, and in addition, a defect in the rolling process performed after casting, that is, meandering the solidified metal strip to the left and right during rolling. There is also a possibility that the pinch roll for suppressing the malfunction may cause wrinkles or cracks in the solidified metal strip after rolling.

  In order to correct the change in the shape of the solidified metal strip for some reason during operation, it is currently necessary to change the operating conditions such as changing the casting speed and the amount of molten metal. Conditions are also responsible for controlling other factors (for example, plate thickness, etc.), and in most cases they cannot be easily changed. In addition, conventionally, the cooling fluid has a maximum flow rate in the cooling flow path of the casting roll. Supply is generally performed, and it is extremely difficult to adjust the shape of the casting roll during casting.

  By the way, in finish rolling rolls for hot rolling, etc., a method of controlling the temperature and the amount of deformation by directly injecting a cooling fluid from the outside to the rolling roll is used. Adopting this method from the viewpoint of avoiding a steam explosion caused by contact with molten metal (temperature higher than the melting point of the metal supplied between the casting rolls. For example, in the case of low carbon steel, it is about 1600 [° C]). It is difficult.

  In view of such circumstances, the present invention can control a solidified metal strip to a target shape, improve the quality of the solidified metal strip itself, malfunction of a pinch roll in a rolling process performed after casting, and solidified metal after rolling. It is an object of the present invention to provide a casting roll shape control method and apparatus for a twin roll type continuous casting apparatus capable of preventing the occurrence of strip wrinkles and cracks.

The present invention is formed so as to extend in the axial direction along the outer peripheral surface of the casting roll and a pair of cylindrical casting rolls disposed so as to be rotationally driven so as to extend in parallel at a necessary interval in the horizontal direction. A cooling flow path and a cooling fluid supply means for supplying a cooling fluid to the cooling flow path, and the cooling fluid supply means supplies the cooling fluid to the cooling flow path to form a cooling flow path aligned in the circumferential direction of the casting roll A twin-roll continuous casting apparatus that continuously casts a solidified metal strip by supplying molten metal between the casting rolls in a state where the casting roll is rotationally driven while circulating a cooling fluid so as to flow alternately in the axial direction. A casting roll shape control method of
Using the numerical model of the relationship between the flow rate of the cooling fluid already obtained and the heat deformation shape of the casting roll, the cooling fluid is supplied to the cooling flow path according to the plate thickness at both ends in the width direction of the solidified metal strip. By adjusting the flow rate of the cooling fluid, the heat transfer coefficient is changed, the amount of heat removed from the casting roll is changed, the temperature distribution of the casting roll is changed, the shape of heat deformation at the axial end of the casting roll is changed, and the casting If the surface temperature of the roll reaches a preset heat-resistant temperature that is the limit of use of the casting roll, or if the temperature of the cooling fluid reaches a preset temperature, both ends of the solidified metal strip in the width direction are temporarily thicker than the value thickness parts are required, twin Russia that even if further necessary to reduce the quantity of heat removed from the casting rolls, flow rate of the cooling fluid, characterized in that to prevent throttled more Those relating to the casting roll shape control method of Le type continuous casting apparatus.

Further, the present invention is a pair of cylindrical casting rolls disposed so as to be rotationally driven so as to extend in parallel at a predetermined interval in the horizontal direction, and formed so as to extend in the axial direction along the outer peripheral surface of the casting roll. And a cooling fluid supply means for supplying a cooling fluid to the cooling flow path, and the cooling fluid supply means supplies the cooling fluid to the cooling flow path and is arranged in the circumferential direction of the casting roll. A twin roll type continuous casting in which a solidified metal strip is continuously cast by supplying molten metal between the casting rolls in a state where the casting roll is rotationally driven while circulating a cooling fluid in an axial direction in the path. A casting roll shape control device for a casting device,
Cooling fluid flow rate adjusting means for adjusting the flow rate of the cooling fluid supplied to the cooling flow path;
A casting roll surface thermometer for detecting the surface temperature of the casting roll;
A cooling fluid thermometer for detecting the temperature of the cooling fluid heated by cooling the casting roll;
Using the numerical model of the relationship between the flow rate of the cooling fluid already obtained and the heat deformation shape of the casting roll, the cooling fluid is supplied to the cooling flow path according to the plate thickness at both ends in the width direction of the solidified metal strip. By adjusting the flow rate of the cooling fluid, the heat transfer coefficient is changed, the amount of heat removed from the casting roll is changed, the temperature distribution of the casting roll is changed, and the heat deformation shape at the axial end of the casting roll is changed. A control signal is output to the cooling fluid flow rate adjusting means, and the surface temperature of the casting roll reaches a heat-resistant temperature that is a preset use limit of the casting roll, or the temperature of the cooling fluid reaches a preset temperature. In such a case, even if the thickness of both ends of the solidified metal strip in the width direction is larger than the required value and the amount of heat removal from the casting roll needs to be further reduced, the flow of the cooling fluid Are those according to the casting roll shape control apparatus for twin-roll continuous casting apparatus characterized by comprising a control means to prevent throttled more.

  According to the above means, the following operation can be obtained.

  The cooling fluid is supplied to the cooling flow path of the casting roll by the cooling fluid supply means via the cooling fluid flow rate adjusting means, and in this state, the casting roll is rotated and the molten metal is supplied between the casting rolls. The solidified metal strip is continuously cast.

Here, a control signal is output from the control means to the cooling fluid flow rate adjusting means according to the plate thickness at both ends in the width direction of the solidified metal strip, and the flow rate of the cooling fluid supplied to the cooling flow path is adjusted. As a result, the heat transfer coefficient changes, the amount of heat removed from the casting roll changes, the temperature distribution of the casting roll changes, and the heat deformation shape at the axial end of the casting roll changes.

In the state where the casting roll is subjected to a heat load during casting and becomes a high temperature, the axial shape of the outer peripheral surface exhibits a complicated shape due to a difference in thermal expansion between the inner peripheral surface side and the outer peripheral surface side, In particular, the local shape change near both ends increases, but the shape at the axial end of the casting roll can be adjusted during casting, so both ends of the solidified metal strip cast by the casting roll It is possible to stabilize the plate thickness in the vicinity.

  Stabilization of the thickness of both ends of the solidified metal strip improves the quality of itself, and also causes a failure in the rolling process performed after casting, that is, the right and left of the solidified metal strip during rolling. It is also possible to avoid malfunction of the pinch roll for suppressing meandering, and generation of wrinkles and cracks in the solidified metal strip after rolling.

  According to the casting roll shape control method and apparatus of the twin roll type continuous casting apparatus of the present invention, the solidified metal strip can be controlled to a target shape, and the quality of the solidified metal strip itself can be improved and the rolling process performed after casting can be performed. An excellent effect of preventing malfunction of the pinch roll and generation of wrinkles and cracks in the solidified metal strip after rolling can be achieved.

1 is an overall schematic configuration diagram showing an embodiment of the present invention. It is sectional drawing which shows the casting roll and solidified metal strip in the Example of this invention. FIG. 3 is a cross-sectional view corresponding to III-III in FIG. 2. It is a perspective view which shows the flow of the cooling fluid supplied to the casting roll in the Example of this invention. It is a diagram which shows the temperature and thermal deformation amount of a casting roll at the time of changing the cooling fluid flow rate supplied to the casting roll in the Example of this invention. It is a diagram which shows an example of the crown process in the cold performed beforehand with respect to a casting roll. It is a diagram which shows an example of the plate | board thickness profile of the solidified metal strip cast with a casting roll.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 5 show an embodiment of the present invention, in which 1 is a pair of cylindrical casting rolls arranged so as to be rotationally driven so as to extend in parallel at a required interval in the horizontal direction, and 2 is the casting roll. 1 is a cooling fluid supply means for supplying a cooling fluid C to the cooling passage 2, and the cooling fluid supply means 3 cools the cooling fluid C. In the twin roll type continuous casting apparatus for continuously casting the solidified metal strip S by supplying the molten metal M between the casting rolls 1 while the casting roll 1 is rotationally driven while being supplied to the flow path 2, Cooling fluid flow rate adjusting means 4 for adjusting the flow rate F of the cooling fluid C supplied to the cooling channel 2 is provided, and the cooling channel 2 is provided in accordance with the thickness of both ends of the solidified metal strip S in the width direction. Adjust the flow rate F of the cooling fluid C to be supplied By, so that by changing the heat transfer rate by changing the quantity of heat removed from the casting rolls 1 changing the temperature distribution of the casting rolls 1, changing the thermally deformed shape in the axial ends of the rolls 1, wherein the cooling fluid flow rate The control means 5 which outputs the control signal A to the adjustment means 4 is provided, and the casting roll shape control apparatus is comprised.

  In the case of the present embodiment, the cooling fluid supply means 3 is a pump 7 for pumping the cooling fluid C in the middle of a circulation line 6 for circulating the cooling fluid C through the cooling flow path 2 of the casting roll 1 as shown in FIG. And a flow rate adjusting valve 8 as the cooling fluid flow rate adjusting means 4, a flow meter 9 for detecting the flow rate F of the cooling fluid C supplied to the cooling flow path 2, and the casting roll 1 is cooled and heated. And a cooling tower 10 for cooling the cooling fluid C.

  Further, a casting roll surface thermometer 11 such as a radiation thermometer for detecting the surface temperature T1 of the casting roll 1, and a cooling fluid thermometer for detecting the temperature T2 of the cooling fluid C heated by cooling the casting roll 1. 12, and inputs the surface temperature T1 of the casting roll 1 detected by the casting roll surface thermometer 11 and the temperature T2 of the cooling fluid C detected by the cooling fluid thermometer 12 to the control means 5. If the surface temperature T1 of the casting roll 1 reaches a heat resistance temperature that is a preset use limit of the casting roll 1, or if the temperature T2 of the cooling fluid C reaches a preset temperature, Even if the plate thickness at both ends in the width direction of the solidified metal strip S is thicker than required, and it is necessary to further reduce the amount of heat removed from the casting roll 1, the flow rate F of the cooling fluid C is not reduced any more. Like Are you.

  Furthermore, the cooling flow path 2 formed so as to extend along the outer peripheral surface of the casting roll 1 is drilled as a plurality of holes arranged in the circumferential direction of the casting roll 1, as shown in FIG. As shown in FIG. 3, the both ends of each are closed by plugs 13 and each of the cooling flow paths 2 as three adjacent holes is formed as one unit, and the cooling flow as two adjacent holes in the unit is set as one unit. The other end of the channel 2 is communicated with the communication hole 2a, and one end of the cooling channel 2 as the remaining one hole and one end of the cooling channel 2 as one adjacent hole are communicated with each other. An annular supply header space 14 is formed on one end side of the casting roll 1 by communicating with the hole 2b, and a desired hole in the one unit is provided in the annular supply header space 14 through a supply hole 15 extending in the radial direction of the casting roll 1. Connect one end of the cooling flow path 2 An annular discharge header space 16 is formed on the other end side of the roll 1, and a desired cooling flow path 2 in the one unit is formed in the annular discharge header space 16 through a discharge hole 17 extending in the radial direction of the casting roll 1. A supply rotary joint 18 (see FIG. 1) is connected to the other end of the casting roll 1 and leads the cooling fluid C to the annular supply header space 14 at one end of the casting roll 1. A discharge rotary joint 19 (see FIG. 1) for discharging the cooling fluid C from the annular discharge header space 16 is attached, and the cooling fluid C flowing through the circulation line 6 (see FIG. 1) of the cooling fluid supply means 3 is supplied to the supply rotary joint 18. To the one end of the cooling flow path 2 through the annular supply header space 14 and the supply hole 15, and the other end of the cooling fluid C supplied to one end of the cooling flow path 2. Circulate in the direction toward the next cooling flow path 2 adjacent through the communication hole 2a at the other end, and circulate the cooling fluid C transferred to the adjacent next cooling flow path 2 toward one end. The cooling fluid C transferred to the next next cooling flow path 2 through the communication hole 2b at one end, and the cooling fluid C transferred to the next further cooling flow path 2 is circulated toward the other end. Then, the discharge rotary joint 19 is returned to the circulation line 6 (see FIG. 1) through the discharge hole 17 and the annular discharge header space 16, and thereby, in the axial direction of the casting roll 1, as shown in FIG. A large number of flows of the cooling fluid C circulating in one reciprocating half zigzag are formed in the circumferential direction of the casting roll 1.

On the other hand, FIG. 5 shows that the flow rate F of the cooling fluid C supplied to the casting roll 1 in the embodiment of the present invention is changed to 2640 [gpm] (gpm: gallon per minute), 2000 [gpm], and 1500 [gpm]. It is a diagram which shows the temperature and the amount of thermal deformation of the casting roll 1 in the case of the above, and the relationship between the flow rate F of the cooling fluid C already obtained in this way and the thermal deformation shape at the axial end of the casting roll 1 The flow rate F is determined in consideration of the numerical model and the shape of the solid metal strip S to be actually cast.

  Next, the operation of the above embodiment will be described.

  As shown in FIG. 1, the cooling fluid C is supplied from a supply rotary joint 18 to a casting roll 1 via a flow rate adjusting valve 8 and a flow meter 9 as a cooling fluid flow rate adjusting means 4 by a pump 7 constituting the cooling fluid supply means 3. Is supplied to the cooling flow path 2, takes heat from the casting roll 1, is returned from the discharge rotary joint 19 to the circulation line 6, cooled by the cooling tower 10, and then circulated by the pump 7. As shown in FIG. 2, the solidified metal strip S is continuously cast by rotating the casting roll 1 and supplying molten metal M between the casting rolls 1.

Here, a control signal A is output from the control means 5 to the flow rate adjusting valve 8 as the cooling fluid flow rate adjusting means 4 in accordance with the thickness of the both ends in the width direction of the solidified metal strip S. The degree of opening is adjusted and the flow rate F of the cooling fluid C supplied to the cooling flow path 2 is adjusted, so that the heat transfer coefficient is changed, and the amount of heat removed from the casting roll 1 is changed. The temperature distribution changes, and as shown in FIG. 5, the heat deformation shape at the axial end of the casting roll 1 changes.

The casting roll 1 has a complicated shape in the axial direction of the outer peripheral surface due to a difference in thermal expansion caused by a temperature difference between the inner peripheral surface side and the outer peripheral surface side when the casting roll 1 is heated to a high temperature during casting. Especially, the local shape change near both ends becomes large, but the shape at the axial end of the casting roll 1 can be adjusted during casting, so that the solidified metal strip cast by the casting roll 1 It is possible to stabilize the plate thickness in the vicinity of both ends of S.

  Stabilization of the plate thickness at both ends of the solidified metal strip S improves the quality of the solid metal strip S itself. In addition, defects in the rolling process performed after casting, that is, the right and left of the solidified metal strip S during rolling. It is also possible to avoid malfunction of the pinch roll for suppressing the meandering of the wire and generation of wrinkles and cracks in the solidified metal strip S after rolling.

  On the other hand, the surface temperature T1 of the casting roll 1 is detected by the casting roll surface thermometer 11, and the temperature T2 of the cooling fluid C heated by cooling the casting roll 1 is detected by the cooling fluid thermometer 12. Are input to the control means 5, respectively, and the surface temperature T1 of the casting roll 1 reaches a preset heat-resistant temperature that becomes a use limit of the casting roll 1, or the temperature T2 of the cooling fluid C is When the temperature reaches a preset temperature, it is assumed that the thickness of both ends of the solidified metal strip S in the width direction is thicker than the required value, and it is necessary to further reduce the amount of heat removed from the casting roll 1. However, since the flow rate F of the cooling fluid C is not reduced any more, there is no fear that the casting roll 1 is heated to a temperature higher than the heat resistance temperature, and a stable operation is possible.

  In addition, since the cooling fluid C is circulated through the multiple cooling flow paths 2 arranged in the circumferential direction of the casting roll 1 so as to be alternately flowed, the temperature distribution in the flow direction which is a concern when the flow rate F is small is the adjacent cooling flow. The paths 2 are substantially cancelled, and problems such as uneven heat removal are unlikely to occur.

  Thus, the solidified metal strip S can be controlled to a target shape, the quality of the solidified metal strip S itself is improved, the malfunction of the pinch roll in the rolling process performed after casting, and the wrinkles and cracks of the solidified metal strip S after rolling. Can be prevented.

  The casting roll shape control method and apparatus of the twin roll type continuous casting apparatus of the present invention is not limited to the above-described embodiment, but instead of using a flow rate adjusting valve 8 as the cooling fluid flow rate adjusting means 4. Of course, various changes can be made without departing from the gist of the present invention, such as adjusting the rotational speed of the pump 7 as the cooling fluid flow rate adjusting means 4.

  In the embodiment of FIG. 1, the cooling water is supplied from one side of the casting roll 1 (left side as viewed in FIG. 1) and discharged from the other side (right side as viewed in FIG. 1). However, the present invention is not limited to only these embodiments. For example, a casting roll having a configuration in which cooling water is supplied from one of the casting rolls and discharged from the same side may be adopted, or two cooling water channels exist in one casting roll, and one cooling water channel The cooling water may flow from one side of the casting roll toward the other, and the other cooling water channel may be configured such that the cooling water flows from the other side of the casting roll toward the other side.

DESCRIPTION OF SYMBOLS 1 Casting roll 2 Cooling flow path 3 Cooling fluid supply means 4 Cooling fluid flow rate adjusting means 5 Control means 6 Circulating line 7 Pump 8 Flow rate adjusting valve 9 Flowmeter 10 Cooling tower 11 Casting roll surface thermometer 12 Cooling fluid thermometer A Control signal C Cooling fluid F Flow rate M Molten metal S Solidified metal strip T1 Surface temperature T2 Temperature

Claims (2)

A pair of cylindrical casting rolls disposed so as to be rotationally driven so as to extend in parallel at a predetermined interval in the horizontal direction, and a cooling channel formed so as to extend in the axial direction along the outer peripheral surface of the casting roll. And a cooling fluid supply means for supplying a cooling fluid to the cooling flow path. The cooling fluid supply means supplies the cooling fluid to the cooling flow path, and alternates in the axial direction with the cooling flow paths arranged in the circumferential direction of the casting roll. The shape of a casting roll of a twin roll type continuous casting apparatus that continuously casts a solidified metal strip by supplying molten metal between the casting rolls while rotating the casting roll while circulating a cooling fluid in a flowing manner. A control method,
Using the numerical model of the relationship between the flow rate of the cooling fluid already obtained and the heat deformation shape of the casting roll, the cooling fluid is supplied to the cooling flow path according to the plate thickness at both ends in the width direction of the solidified metal strip. By adjusting the flow rate of the cooling fluid, the heat transfer coefficient is changed, the amount of heat removed from the casting roll is changed, the temperature distribution of the casting roll is changed, the shape of heat deformation at the axial end of the casting roll is changed, and the casting If the surface temperature of the roll reaches a preset heat-resistant temperature that is the limit of use of the casting roll, or if the temperature of the cooling fluid reaches a preset temperature, both ends of the solidified metal strip in the width direction are temporarily thicker than the value thickness parts are required, twin Russia that even if further necessary to reduce the quantity of heat removed from the casting rolls, flow rate of the cooling fluid, characterized in that to prevent throttled more Casting roll shape control method of Le type continuous casting apparatus. A pair of cylindrical casting rolls disposed so as to be rotationally driven so as to extend in parallel at a predetermined interval in the horizontal direction, and a cooling channel formed so as to extend in the axial direction along the outer peripheral surface of the casting roll. And a cooling fluid supply means for supplying a cooling fluid to the cooling flow path. The cooling fluid supply means supplies the cooling fluid to the cooling flow path, and alternates in the axial direction with the cooling flow paths arranged in the circumferential direction of the casting roll The shape of a casting roll of a twin roll type continuous casting apparatus that continuously casts a solidified metal strip by supplying molten metal between the casting rolls while rotating the casting roll while circulating a cooling fluid in a flowing manner. A control device,
Cooling fluid flow rate adjusting means for adjusting the flow rate of the cooling fluid supplied to the cooling flow path;
A casting roll surface thermometer for detecting the surface temperature of the casting roll;
A cooling fluid thermometer for detecting the temperature of the cooling fluid heated by cooling the casting roll;
Using the numerical model of the relationship between the flow rate of the cooling fluid already obtained and the heat deformation shape of the casting roll, the cooling fluid is supplied to the cooling flow path according to the plate thickness at both ends in the width direction of the solidified metal strip. By adjusting the flow rate of the cooling fluid, the heat transfer coefficient is changed, the amount of heat removed from the casting roll is changed, the temperature distribution of the casting roll is changed, and the heat deformation shape at the axial end of the casting roll is changed. A control signal is output to the cooling fluid flow rate adjusting means, and the surface temperature of the casting roll reaches a heat-resistant temperature that is a preset use limit of the casting roll, or the temperature of the cooling fluid reaches a preset temperature. In such a case, even if the thickness of both ends of the solidified metal strip in the width direction is larger than the required value and the amount of heat removal from the casting roll needs to be further reduced, the flow of the cooling fluid The casting roll shape control apparatus for twin-roll continuous casting apparatus characterized by comprising a control means to prevent throttled more.

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