WO2014142597A1

WO2014142597A1 - Casting equipment and casting method using same

Info

Publication number: WO2014142597A1
Application number: PCT/KR2014/002153
Authority: WO
Inventors: 오경식; 이주동; 최정윤; 김성줄
Original assignee: 주식회사 포스코
Priority date: 2013-03-15
Filing date: 2014-03-14
Publication date: 2014-09-18
Also published as: EP2974810A4; BR112015020565B1; BR112015020565A2; CN105026073B; EP2974810B1; JP6055114B2; US20160023269A1; TR201815354T4; ES2693560T3; KR101511723B1; JP2016503730A; KR20140113040A; CN105026073A; EP2974810A1

Abstract

The present invention relates to casting equipment for producing a casting with a large cross-section for a very thick steel material and a casting method using the same, and the casting equipment includes: a casting part with a passage for a molten steel for casting the molten steel into a casting; a support part arranged separately from the casting part for receiving and supporting the casting in at least one of the sides of the casting; and a solidifying part arranged outside the casting provided with a first quality control device for solidifying the casting, whereby the casting method includes the steps of: preparing a molten steel for casting; casting the molten steel in the casting part with the passage opened or closed into a casting; conveying the casting to the solidifying part; and conveying the solidified casting to a subsequent process so as to improve the quality of the casting, thus increasing substantially the yield rate of castings. In addition, the molten steel is continuously stirred through the quality control device and a solidification inducement device from the start of casting to the end of solidifying the casting so as to enhance the equiaxed surface ratio of the casting, and decrease segregation/porosity and the internal defects such as a pipe generated at an end of the casting. Also, when producing a casting with a large cross-section for a very thick steel material, the casting part can produce another casting continuously while the previous casting is solidified in the solidifying part, thus saving the time consumed for solidifying the casting for a very thick steel material by means of the continuous solidifying part. This prevents the casting process from being stopped, thereby enhancing the productivity of a casting and the efficiency of the casting equipment.

Description

Casting equipment and casting method using the same

The present invention relates to a casting facility and a casting method using the same, and more particularly, to provide a casting facility and a casting method using the same, which can easily manufacture the cast steel for ultra-thick steel, and improve the quality and error rate and productivity of the cast steel.

In general, the ultra-thick steel has a thickness of 100mm or more, and limits the reduction ratio (casting thickness / product thickness) according to its use to manage internal quality such as porosity, and mechanical properties such as impact and toughness. . For example, offshore structural steels require ultra-thick steel materials with a reduction ratio of 4 or more, and pressure and wind structural steels require a reduction ratio of 3 or more.

Currently, ultra-thick steels are manufactured through predetermined post-processing such as forging and hot rolling of cast steel produced by ingot or continuous casting. At this time, in the case of manufacturing the ultra-steel material by the ingot process, which is the former, the ingot is forged and manufactured into an ultra-steel product or an additional rolling process is applied. In particular, the ultra-thick steel, which requires high rolling reduction, is made through a rolling process after forging a cast steel cast ingot because most of the internal quality is important.

As such, in the case of manufacturing ultra-thick steel using cast steel cast ingots, it is possible to cope with the production of ultra-thick steel having a high reduction ratio, and it is an advantageous process for small-lot production due to the demand for ultra-thick steel. However, slabs manufactured using the ingot method are required to cut the unhealthy parts in order to remove the unhealthy parts occurring in the hot water part and the hot water part. Thus, the cutting of the upper and lower regions of the cast steel causes the real rate inferiority of the cast steel to increase the production cost for producing the ultra-thick steel.

On the other hand, in the case of manufacturing the ultra-thin steel using the cast produced by the latter continuous casting method, in general, the ultra-thick steel is manufactured by rolling the continuously cast steel casting. This is very good compared to the ingot in the real rate is superior to the ingot process in terms of production cost, but when producing a steel grade that requires a high reduction ratio, there is a problem that the thickness of the ultra-thick steel due to the limited cast steel thickness.

In addition, the ultra-thick steel is relatively thick compared to the general cast, it takes a long time until the cast completely solidified after casting. If the existing casting method for continuous casting of molten steel produces a cast steel for thick-walled steel that is thicker than the thickness of the general cast steel produced by the general machine, the machine equipment needs to be solidified to the inside of the cast. It will be very long, which will require huge initial costs in terms of production costs due to the large size of the equipment.

In addition, the probability of occurrence of defects in cast steel is higher than that of ingot material, and there is a high possibility that internal defects in cast steel remain in ultra-thick steel products. In addition, since the continuous casting equipment for casting production is optimized for mass production, there is a disadvantage in small-lot production.

Therefore, the development of new equipment and processes for the production of cast steel for ultra-thick steel materials having a high reduction ratio, which is not easy to produce in the general casting equipment is urgently required. In other words, in terms of quality of steel, it is possible to improve the internal quality and error rate more than or equal to that of ingot cast, and in terms of productivity, it is advantageous to produce various kinds of small-lot ultra-thick steel, and to increase productivity compared to ingot cast. And processes are required.

The present invention provides a casting facility and a casting method using the same, which is easy to manufacture cast steel for ultra-thick steel.

The present invention provides a casting facility and a casting method using the same that can increase the quality and error rate of the cast.

The present invention provides a casting facility and a casting method using the same that can increase the productivity of the cast steel and the efficiency of the process equipment.

Casting equipment according to an embodiment of the present invention, forming a passage through which molten steel, the casting part for casting the molten steel into a cast steel, and is disposed spaced apart from the casting portion and receives the cast steel from the casting portion, It is disposed on at least one of the side of the support and includes a support for supporting the slab, and a solidification unit provided with a first quality controller provided on the outside of the cast to induce the solidification of the cast.

The first quality controller is provided with a first stirrer disposed close to the outer side of the cast slab, which can move up and down in the longitudinal direction of the cast slab, spaced below the first stirrer, and which can move up and down in the longitudinal direction of the cast slab. 2 may include a stirrer and a first heater installed to be able to move back and forth to the upper region of the cast steel, and to heat the upper portion of the cast steel.

The first stirrer may be a coil wound around the cast piece in a circular shape.

The casting part may include a receiving part having a space in which the molten steel is accommodated, a drawer for drawing the cast piece downward from the receiving part, and a second quality controller provided outside the passage.

The receiving portion may include a mold forming a path through which the molten steel supplied to the tundish passes, and the mold may be formed such that the cast steel has a thickness of 800 mm or less and a width of 2000 mm or less.

The second quality controller is disposed outside the mold, and advances to the stirring unit including at least one or more agitators for stirring at least one of the molten steel and the non-solidified molten steel in the cast steel. It may be installed to include a second heater for heating the upper portion of the cast.

The stirring unit is disposed in close proximity to the mold and provided with a third stirrer capable of lifting up and down in the drawing direction of the cast steel, and spaced below the third stirrer, and including a fourth stirrer capable of lifting up and down in the drawing direction of the cast steel. can do.

The third stirrer may be a coil wound around the mold or around the cast piece in a circular shape.

The casting part may be provided with a pusher for separating the cast piece from the drawer, and the pusher may be installed to reciprocate forward and backward toward the solidification part.

The caster may be transferred from the casting part to the solidification part, or a conveyor may be provided to transfer the slab from the solidification part to the outside of the solidification part.

In the casting method according to an embodiment of the present invention, a process of preparing molten steel to prepare a casting, a process of casting the molten steel in a casting part to open and close the passage through the molten steel, produced through the casting And transferring the cast steel to a solidification part, and after the solidification of the cast steel is completed, the cast steel is transferred to a later process.

After the cast is transferred to the solidification part, the casting process of the molten steel may be repeated in the casting part.

When the process of casting the molten steel is repeated, the process of transferring the cast steel to the solidification part may be performed while the molten steel is transferred to the casting part to prepare the casting.

In the case of the yeonyeonju casting the molten steel is a one-time casting, the cast steel may complete the solidification in the casting portion or transferred to the solidification portion may complete the solidification.

The molten steel may be cast at a circumferential speed of 0.3 m or less per minute.

According to the casting facility and the casting method using the same according to an embodiment of the present invention, it is possible to improve the error rate of the cast produced by the continuous casting. That is, when solidifying the cast slab cast in the casting portion in the casting portion or the solidification portion, by delaying the solidification of the upper portion of the slab by using a second heater or the first heater, the pipe length generated on the upper portion of the slab to reduce the The error rate can be improved.

In casting, the molten steel remaining in the mold is stirred to improve the internal quality.After casting is completed, the unsolidified molten steel in the casting is stirred to increase the equiaxed crystallization rate, decrease segregation / porosity, and pipes generated at the end of the cast steel. Internal defects can be reduced.

In addition, the present invention can continuously cast another cast in the casting portion during the process of solidification of the cast in the solidification portion. Therefore, since the time required for solidification of the cast steel for the ultra-thick steel cast can be completed in the solidification part, casting of molten steel may not be interrupted, thereby increasing the productivity of the cast steel and the efficiency of the process equipment.

1 is a view showing a casting facility according to an embodiment of the present invention.

2 is a flow chart showing a casting method according to an embodiment of the present invention.

3 is a view showing an operating state of the casting equipment according to the casting method of FIG.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like numbers refer to like elements in the figures.

1 is a view showing a casting facility according to an embodiment of the present invention. 2 is a flow chart showing a casting method according to an embodiment of the present invention. 3 is a view showing an operating state of a casting facility according to the casting method of FIG. At this time, (a) to (f) of Figure 3 sequentially shows the change of the casting equipment operating to produce the cast steel.

Referring to FIG. 1, a casting facility 1 according to an embodiment of the present invention is a facility for producing cast steel for ultra-thick steel, forming a passage through which molten steel passes, and casting part 1a for casting molten steel into cast steel 1a. And a cast part 1a spaced apart from the cast part 1a, the caster receives the cast from the cast part 1a, and is disposed on at least one of the side surfaces of the cast part to support the cast part, and is provided outside the cast part. It comprises a solidification unit 1b is provided with a first quality controller 600 for inducing solidification of the convenience.

The casting part 1a is a section in which continuous casting of the refined molten steel is performed. The receiving part 100 in which the molten steel is accommodated, the drawer 200 for drawing the cast slab from the receiving part 100 downward, and the molten steel are passed through. And a second quality controller 300 provided outside the passage.

The receiving part 100 forms a space for receiving molten steel until casting of molten steel is started, and the ladle 120 in which the molten steel is accommodated, and the tundish 140 and the tundish receiving the molten steel from the ladle 120 140) includes a mold 160 spaced apart from the bottom.

The ladle 120 is a container for accommodating molten steel that has been refined, and may be variously manufactured in a hollow shape in which an inner space capable of accommodating molten steel is formed. In general, the ladle 120 may be provided in plurality in order to increase the circulation rate of the continuous casting equipment.

The tundish 140 is manufactured in a hollow container shape capable of accommodating molten steel supplied from the ladle 120 therein. In addition, the outlet of the molten steel is formed at the bottom of the tundish 140, the molten steel accommodated in the tundish 140 may be discharged to the outside through the outlet. At this time, the molten steel accommodated in the tundish 140 is injected into the mold 160 after separation of the inclusions contained in the molten steel by staying in the tundish 140 for a predetermined time.

The mold 160 is provided to shape the molten steel injected from the tundish 140 into an appropriate size and produce the cast steel. The mold 160 forms a width and a thickness of a path through which the molten steel passes. At this time, the mold 160 of the present invention may be formed to have a thickness of less than 800mm and a width of less than 2000mm to correspond to the size of the cast steel for the ultra-thick steel. That is, by using the mold 160, the thickness of which is significantly increased compared to the mold of the conventional casting equipment, it is possible to make the cast steel subjected to the forging and rolling process to have a thickness used for the ultra-thin steel.

On the other hand, the guide roll 170 for guiding the cast steel with the initial shell formed through the mold 160 to the outside of the mold 160, a cooling nozzle (not shown) for cooling the cast steel guided from the guide roll 170 and the mold in the mold A vibrator (not shown) may be provided to transmit vibration to the mold 160 so that the piece is easily drawn out of the mold 160. At this time, the configuration of the guide roll 170, the cooling nozzle and the vibrator need not be limited to a specific configuration in the present invention, its various configurations and operation methods are already well known to those skilled in the art, detailed description thereof will be omitted.

The drawer 200 is a device for drawing the cast slab from the receiving portion 100 to the lower portion, is initially disposed inside the mold to receive the molten steel to prevent the molten steel outflow to the mold 160, the initial solidified cast slab The surface plate 220 connected to the 240, and the driver 240 for drawing the cast slab to the bottom.

The surface plate 220 is provided to connect the cast steel and the driver 240, and a plate having a surface of a specific shape is used to facilitate the connection with the cast steel. In the present invention, the shape and material of the surface plate 220 is not limited, but is preferably made of a material that does not cause deformation due to the high temperature of the cast when in contact with the cast.

The driver 240 is a device for lowering the surface plate 220, and the base plate 220 connected to the driver 240 may be lowered to draw the cast slab connected to the surface plate 220 downward. The driver 240 may be lowered when the cast steel is drawn out, and an apparatus capable of lifting and lowering may be used to place the surface plate 220 in the mold 160 at the beginning of casting. That is, the driver 240 may be a device capable of lifting and lowering.

The second quality controller 300 is provided to improve the quality of the cast steel drawn from the drawer 200, and is disposed outside the mold 160 to form the molten steel in the mold 160 and the unsolidified molten steel in the cast steel. A stirring unit 320 including at least one stirrer for stirring at least one and a second heater 340 is installed to be able to advance to the lower region of the mold 160 to heat the upper portion of the cast.

Stirring unit 320 is a device for improving the quality of the cast steel provided with at least one stirrer on the outside of the mold 160, the third stirrer (close to the mold 160 is possible to move up and down in the drawing direction of the cast steel ( 322 and a fourth stirrer 324 spaced below the third stirrer 322 and capable of lifting up and down in the drawing direction of the cast steel. That is, the stirring unit 320 may increase the quality of the cast steel by agitating at least one of molten steel accommodated in the molten state in the mold 160 and unsolidified molten steel in the manufactured cast steel.

As shown in FIG. 1, the third stirrer 322 is spaced apart from the side of the mold 160 by a predetermined distance, and the molten steel contained in the mold 160 is stirred during casting. And when casting is started, the predetermined distance is dropped with the cast steel, and the unsolidified molten steel in the cast steel is stirred. That is, when molten steel is injected into the mold 160, the third stirrer 322 stirs the molten steel by flowing electromagnetic to the molten steel from the side of the mold 160, and when the injection of the molten steel in the mold 160 is completed, While lowering together, the unsolidified molten steel inside the cast can be stirred. In this case, an electromagnetic stirrer (EMS) may be used as the third stirrer 322. At this time, the electromagnetic stirrer that can be used as the third stirrer 322 has a frequency (Hz) of a low range typically, which is a frequency sufficient to stir the molten steel in the molten state.

The fourth stirrer 324 is provided below the third stirrer 322 to be spaced a predetermined distance, and descends in the drawing direction of the cast steel and stirs the unsolidified molten steel in the cast steel. In this case, the fourth stirrer 324 may use a final coagulation device (FEMS; Final Electro Magnetic Stirrer). The fourth stirrer 324 is disposed in the lower portion relative to the third stirrer 322, and within the solidification portion of the lower region of the cast steel (the lower region from the center in the longitudinal direction of the cast steel) where the solidification of the cast steel is somewhat advanced. It is preferable to use a stirring device having a higher frequency (Hz) than the third stirrer 322 because the molten steel present must be stirred.

As such, the stirring unit 320 can increase the equiaxed crystallization in the slab by stirring the solidified and solidified molten steel in the cast, and can reduce the occurrence of segregation and voids. On the other hand, the present invention is not limited to the stirring portion of the slab to which the third stirrer 322 and the fourth stirrer 324 and the stirrer lifting and lowering width in which the stirrers are raised and lowered, the movement range varies depending on the casting conditions Can be operated.

The second heater 340 is disposed outside the mold 160 and installed to be able to move forward and backward in the immediate lower region (the drawing path of the cast steel) of the mold to heat the upper portion (tail portion) of the cast steel cast. As the device, in the present embodiment, an induction heating method (induction heating device; EMH, Electro Magnetic Heater) was used. The second heater 340 indirectly heats the upper side of the cast using electromagnetic generated from the induction heating coil by the supply of power, and is wound so as to be spaced apart at regular intervals from the four direction sides of the cast. Thus, the second heater 340 is preferably used induction coil having a shape corresponding to the cross-sectional shape of the cast steel, but is not limited to this may be wound in various forms.

On the other hand, the casting unit (1a) may be provided with a pusher 400 for transferring the cast slab to the solidification unit (1b) after the casting of molten steel is completed.

The pusher 400 is disposed at a position opposite to the solidification portion 1b of the side of the casting portion 1a, and pushes the side of the cast steel to separate the cast steel from the drawer 200 to the solidification portion 1b. It is a device that delivers. In this case, the pusher 400 may be an apparatus capable of reciprocating a predetermined distance, for example, a stepping motor, a piston / actuator, a solenoid, or the like may be used. For example, when the piston cylinder mechanism is used as the pusher 400, the piston is inserted into the cylinder and reciprocated so that the cast can be returned to its original state after being pushed toward the solidification portion 1b. In this case, the apparatus for transmitting the cast piece 1a of the caster 1a to the solidification unit 1b is not limited to the pusher 400, and various devices may be used.

The solidification portion 1b is a place where the cast steel is received to solidify the cast steel cast from the above-described casting portion 1a. The solidification portion 1b is disposed on at least one of the side surfaces of the cast steel to support the cast steel, and It is provided on the outside includes a first quality controller 600 for inducing solidification of the cast steel. The solidification part 1b receives the cast steel at a predetermined distance from the casting part 1a, transfers the cast steel to a post process (for example, forging or rolling) after the solidification of the cast steel is completed.

The support part 500 is provided to allow the cast piece to be stably positioned at the solidification part 1b, the support block 520 disposed in contact with the lower part of the cast piece, and the support frame 540 disposed to surround a part of the side surface of the cast piece. It includes. However, the configuration of the support unit 500 is not limited thereto, and the cast unit may be supported by various apparatuses and methods within a range that does not prevent movement of the first quality controller 600.

The support block 520 may be a block having a shape similar to that of the surface plate 220 of the casting part 1a. The support block 520 serves to support the lower part of the slab disposed in the solidification part 1b in the drawing direction, that is, the longitudinal direction.

The support frame 540 may be disposed to surround a part of the side surface of the cast steel, as shown in FIG. 1 and spaced apart a predetermined distance from the side surface of the cast steel in order to suppress and prevent the slab disposed in the longitudinal direction from falling.

The first quality controller 600 is provided on the outside of the cast steel to ensure the quality of the cast steel, the first stirrer 620 and the first stirrer disposed close to the outside of the cast steel can be lowered in the longitudinal direction of the cast steel, A second stirrer 640 spaced apart from the lower portion of 620 and capable of lifting up and down in the longitudinal direction of the cast steel and a first heater 660 for heating the upper portion of the cast steel. That is, since the solidification of the naturally cooled cast steel is not completed, the first quality controller 600 may have the same or similar device as the casting part 1a to continue the treatment process for improving the quality of the cast steel.

The first stirrer 620 is a device for stirring the unsolidified molten steel in the cast steel delivered to the solidification unit 1b, and is disposed spaced apart from the cast steel by a predetermined distance. The first stirrer 620 is lowered to be disposed on the side of the cast when the cast is delivered to the solidification unit (1b) in a state arranged at the same or similar height as the third stirrer (322) of the casting (1a) It can be installed to be descendable. The first stirrer 620 is disposed above the outer side of the cast steel. That is, it is disposed above the center of the cast steel with respect to the longitudinal direction of the cast steel. At this time, the upper unsolidified region of the cast steel to be stirred by the first stirrer 620 is relatively less solidified than the lower portion of the cast steel, and thus includes a large amount of unsolidified molten steel in the cast steel as compared to the lower region of the cast steel. Thus, an electromagnetic stirrer (EMS) similar to the third stirrer 322 may be used.

On the other hand, the first stirrer 620 is a device similar to the third stirrer 322 is used, but the magnitude or frequency of operating time of the frequency generated by the first stirrer 620 and the third stirrer 322 may be different, respectively. have. That is, the third stirrer 322 applies a frequency within about 1 Hz because it stirs the molten steel in the mold 160 or stirs the molten steel in the initial cast where the solidification proceeds. At this time, the third stirrer 322 is operated until the molten steel is injected into the mold 160 and the molten steel is cast as a cast and transferred to the solidification part 1b. The first stirrer 620 is solidified shell having no mold and thicker than the cast steel cast in the casting part, due to the characteristics of the cast steel delivered to the solidifying unit (1b), the magnetic field of the first stirrer 620 is thickened solidification To agitate the unsolidified molten steel in the slab through the shell, operate at a frequency of up to 5 Hz until the casting is completed. However, since the solidification state of the cast steel occurs in a variety of forms according to the casting conditions and casting conditions, the application frequency of the third stirrer 322 and the first stirrer 620 is applied in various operating patterns in the range of 0 ~ 5Hz Can be. In addition, the first stirrer 620 located in the solidification portion 1b of FIG. 3D may stir the unsolidified molten steel in the slab to uniform the temperature of the unsolidified molten steel in the slab when the solidification portion 1a solidifies the slab. The first heater 660 heats the upper side of the cast steel to prevent the top of the cast from pre-solidification can be very effective when reducing the pipe defects in the cast. Similarly, the third stirrer 322 located in the casting part 1a of FIG. 3F stirs the unsolidified molten steel in the slab when the casting part 1a solidifies, thereby making the temperature of the unsolidified molten steel in the slab uniform. The two-heater heats the upper side of the cast steel, preventing the top of the cast from presolidifying, which can be very efficient when reducing pipe defects in the cast.

The second stirrer 640 is provided to be spaced apart from the lower portion of the first stirrer 620 by a predetermined distance and is installed to be able to move up and down in the longitudinal direction of the cast steel to stir the unsolidified molten steel in the cast steel. That is, the second stirrer 640 is disposed below the center of the cast steel with respect to the longitudinal direction of the cast steel, and the fourth stirrer 324 to stir the unsolidified molten steel in the outer lower region of the cast steel where solidification has been performed for a predetermined time. Similar to the final coagulation device (FEMS; Final Electro Magnetic Stirrer) may be used, the magnitude of the frequency or the operating time of the second stirrer 640 and the fourth stirrer 324 may be different. That is, the fourth stirrer 322 applies a frequency within a maximum of 3 Hz in order to stir the unsolidified molten steel in the slab in which the solidification is progressing in the casting part 1a. At this time, the fourth stirrer 324 operates until the cast steel cast from the casting part 1a is transferred to the solidification part 1b. The second stirrer 640 forms a solidifying shell thicker than the cast steel cast in the casting part due to the characteristics of the cast steel delivered to the solidifying part 1b, and operates until the casting of the cast steel is completed by applying a frequency of up to 6 Hz. do. However, since the solidification state of the cast steel occurs in a variety of forms according to the casting conditions and casting conditions, the application frequency of the fourth stirrer 324 and the second stirrer 600 is applied in various operating patterns in the range of 0 ~ 6Hz Can be.

On the other hand, in the present embodiment, the first stirrer 620 and the second stirrer 640 are provided with a plurality to stir the unsolidified molten steel in different areas of the cast steel, respectively, but in the slab in the solidified portion (1b) The apparatus and method for stirring the solidified molten steel is not limited thereto. That is, one stirrer may be provided and the shape of various methods and apparatuses capable of stirring the entire region from the upper side to the lower side of the slab may be changed while the frequency of the stirrer is changed.

As described above, the first stirrer 620 and the second stirrer 640 stir the molten steel until the slab transferred to the solidification part 1b is solidified, similarly to the stirring unit 320 of the casting part 1a. It is possible to increase the equiaxed crystal yield and to reduce the degree of segregation and voids to increase the quality of the cast.

On the other hand, the third stirrer 322 and the first stirrer 620 applied to the present invention is applied to a significantly increased size than the mold applied in the existing continuous casting machine, in order to secure a uniform stirring force of the molten steel in the mold, The coil wound around or around the cast steel in a circular shape was disposed in a circular shape so as to perform rotational stirring on the non-solidified molten steel in the mold or the cast steel to ensure a uniform stirring force.

The first heater 660 is installed so as to be able to move forward and backward from the outer side of the cast steel to the upper region of the cast steel so as to heat the upper portion of the cast steel to heat the upper portion (tail portion) of the cast steel delivered to the solidification portion 1b. It is a device for. Since the first heater 660 is similar in configuration and effect to the second heater 340 described above, a detailed description thereof will be omitted.

The above-described casting facility 1 is provided with a conveyor for transferring the cast from the casting portion 1a to the solidification portion 1b, and transferring the cast steel from the solidification portion 1b to the outside of the solidification portion 1b, that is, a post process. Can be.

The conveyer 700 is disposed on one side of the solidification portion 1b and is formed to be capable of moving forward and backward to the casting portion or the solidification portion, and is an apparatus for transferring the cast steel. The feeder 700 is in contact with the cast in the cast (1a) to tilt the cast or to move the cast from the cast (1a) to the solidifying portion (1b) and the tilting portion 720, the tilting portion 720 It includes a driver 740 for controlling the operation of.

The tilting unit 720 is disposed on one side of the cast steel, and is tilted or moved back and forth by the driving unit to move the cast steel, and connects the support block 520 of the solidification unit 1b to transfer the cast steel. That is, a support block 520 for supporting the cast steel is connected to one side of the tilting unit 720 and the cast steel is disposed on the support block 520 to transfer the cast steel from the casting portion 1a to the solidification portion 1b. have. When the tilting part 720 is transferred from the coagulation part 1b to the outside of the coagulation part, the tilting part 720 is inclined in the state in which the slab is in contact with one side of the tilting part 720 and is disposed in the conveying direction. The cast steel may be seated on the tilting portion. At this time, the roller 725 may be mounted on the side in contact with the tilting unit 720 and the cast steel to facilitate the transfer of the cast steel.

The driving unit 740 controls the operation of the tilting unit 720, and the tilting unit 720 may move forward and backward and move closer to or away from the casting unit 1a. In addition, the driving unit 740 may be in communication with the roller table 800 for guiding the tilting unit 720 and the slab to a later process by tilting the tilting unit 720. In this case, the driving unit 740 may be a device capable of reciprocating a predetermined distance, such as the pusher 400 of the casting unit 1a, for example, when using a piston cylinder mechanism, the tilting unit at one end of the piston 720 may be connected to enable the angle adjustment.

As described above, in the present embodiment, the above method and apparatus are used as the feeder 700 for transferring the cast steel, but the apparatus and the operating method used in the feeder 700 are not limited thereto, and the casting part 1a is provided. Various apparatuses and methods capable of easily transferring the slab when transferring the slab from the coagulation unit 1b or from the coagulation unit 1b to a post process are available.

Hereinafter, the casting method using the above-described casting equipment will be described.

Referring to Figure 2, the casting method according to an embodiment of the present invention, the process of preparing the casting by preparing molten steel, the process of casting the molten steel in the casting to enable the opening and closing of the passage through the molten steel, casting It includes the process of transporting the produced cast through the solidification unit.

First, the molten steel after the refining is received in the ladle 120, and then transferred to the casting to start casting. The molten steel transferred to the casting part is supplied to the tundish 140 from the ladle 120, and then a process of the casting part 1a is performed by injecting the molten steel into the mold after the floating separation of the inclusions in the tundish 140 for a predetermined time ( S100). At this time, as shown in Figure 3a, the surface plate 220 is placed in the mold to complete the casting preparation in a state in which the molten steel injected into the mold 160 is blocked from being discharged to the outside (S120).

After the preparation of the casting is completed, as shown in Figure 3b, the drawer 200 is operated to lower the surface plate 220, and casting starts as the cast (S ₁ ) connected to the surface plate 220 is drawn to the bottom Cast steel is produced (S140). At this time, before the casting is started, the third stirrer 322 is operated to stir the molten steel in the mold. The cast steel produced is manufactured to a maximum thickness of 800 mm and a maximum width of 2000 mm, and cast at a casting speed of 0.3 m or less per minute. It is necessary to use the mold 160 with increased thickness of the cast steel to obtain the final product with increased thickness due to the characteristics of the ultra-thin steel, and the reason for casting at a low casting speed of 0.3 m / min is that the thick steel cast steel has a solidification rate. It is necessary to secure the internal quality by suppressing the occurrence of segregation by casting at a low circumferential speed to ensure the internal quality, and to secure a solidified shell of sufficient thickness during casting.

While casting is in progress, the third stirrer 322 continuously stirs the molten steel in the mold, and the molten steel that is not solidified inside the cast steel is continuously stirred through the fourth stirrer 324 due to the thick thickness of the cast steel and the solidification proceeds. do. As described above, the third stirrer 322 and the fourth stirrer 324 can refine the structure of the cast steel by continuously stirring the molten steel, thereby improving the quality of the cast steel and improving the equiaxed crystallinity of the cast steel.

When casting is completed in the casting part 1a (S160), the cast steel S ₁ located in the casting part 1a is separated from the surface plate by the pusher 400 and supported by the conveyor 700 to move to the solidification part. (S200). At this time, when the cast (S ₁ ) is received by the pushing force by the pusher 400, it may be transferred to the solidification unit (1b) in the state that the solidification of the surface to the extent that it does not deform. On the other hand, the stirring unit 320 moving from the casting portion (1a) to the upper and lower solidification of the cast steel is returned to its original position so as not to interfere with the transfer of the cast steel (S ₁ ).

After the cast piece is transferred to the solidification part 1b, the process (S300) of the solidification part 1b progresses a process of finally completing the solidification of the slab S ₁ . That is, since the cast (S ₁ ) is solidified in the solidification unit 1b, the casting process may proceed in the casting unit 1a. When the solidification of the cast steel (S ₁ ) is started, the first quality controller 600 provided in the solidified portion (1b) is disposed to be spaced apart from the outer surface of the slab to descend or rise at the original position. That is, as illustrated in 3d, a first agitator 620, a second agitator 640 is disposed in the main outer surface of convenience for stirring the non-solidified molten steel inside the cast steel (S _1), the cast steel (S ₁₎ It will work until the coagulation is complete.

In the process of solidifying the cast steel, the first heater 660 indirectly heats the upper portion of the cast steel in each region, so that the upper portion of the cast steel is solidified while suppressing the release of heat from the side of the upper portion of the cast steel. do. This may indirectly heat the upper side of the cast steel to inhibit or prevent presolidification of unsolidified areas of the upper portion of the cast, thereby minimizing solidification shrinkage defects such as pipes. Therefore, the error rate of the upper part of the cast can be improved to increase the error rate of the final cast.

As such, when the solidification of the cast in the solidification unit 1b is completed (S340), as shown in Figure 3e, the slab is inclined by the tilting unit 720 of the feeder 700, the tilting of the feeder 700 The unit 720 communicates with the roller table 800 disposed in the vicinity of the feeder 700, and the cast steel is transferred to the post process along the roller table 800 (S360).

As such, the repetition of the process of FIGS. 3A to 3F is not limited to the number of times but may be repeatedly. That is, as shown in (b) of FIG. 2, after the process of the casting part 1a is completed, the cast part (S ₁ ) moves to the solidification part to perform the casting part (the solidification process) during the solidification part process (casting solidification process). In 1a), the process of the casting part 1a is re-produced to produce another cast (S2) and repeatable until a desired quantity is obtained.

After repeating the above process, if the process of the casting unit 1a is no longer progressed, that is, the cast steel (S2) of Figure 3e is transferred to the solidification unit (1b) after the last cast in the casting unit (1a) When Se is produced, the slab Se of the casting part 1a is not transferred to the solidification part 1b, and solidification can be completed in the casting part 1a. That is, by using the second quality controller 300 provided in the casting part (1a) can be transferred to the post-process after completing the solidification of the cast (Se) (S360). In this case, the second heater 340 of the casting part 1a may indirectly heat the upper portion of the slab Se and serve as the first heater 660 of the solidification part 1b. However, the last produced cast (Se) may be transferred to the post-process after completing the solidification process after being transferred to the coagulation unit (1b) like the previously produced cast (S ₁ , S ₂ ). Therefore, the position where the last cast (S _e ) is solidified is not limited.

Hereinafter, the effects of the present invention will be described in more detail through experimental examples.

[Table 1] shows the results of the change in the thickness of the cast steel under various process conditions for producing the ultra-thick steel materials and the error rate of the finally produced cast steel.

Table 1

	Cast thickness (mm)			Real rate (%)
	Early	Mid-term	last period	Real rate (%)
Comparative Example 1	1500	300	178	52
Comparative Example 2	450	-	150	95
Example	800	300	178	89

Here, the initial thickness of the cast steel represents the thickness of the cast steel when no separate post-process is performed on the cast slab. In addition, the slab thickness in the middle stage represents the thickness of the slab after the forging step of tapping or pressing the slab, and the thickness of the slab in the final stage represents the thickness of the slab after the rolling process.

Each cast (Comparative Example 1, Comparative Example 2, Example) shown in Table 1 after the casting process, after performing at least one of the forging and rolling process, finally produced cast steel for the ultra-thick steel cast From Table 1, the following results can be confirmed.

Comparative Example 1

The cast steel of Comparative Example 1 is a cast steel produced through an ingot process, and can be obtained by supplying molten steel to the mold and cooling it. The cast thus produced had an initial thickness of 1500 mm. Thereafter, after the forging process and the rolling process to form a thickness for the ultra-thick steel material, and finally has a thickness of 178mm. However, it can be seen that the overall error rate has a low value of 52%.

Comparative Example 2

The slab of Comparative Example 2 is a slab slab produced through a general casting facility, it can be produced by continuously injecting and solidifying molten steel supplied from the steelmaking furnace into the mold. The cast steel thus produced has a very high real value of 95%. However, the casting equipment generally used has a thickness of 150 mm after completing the rolling process because the thickness of the initial cast is produced to 450 mm. Thus, it can be seen that the thickness of 150mm is limited when using the cast steel for the ultra-thick steel.

EXAMPLE

The cast of the embodiment is a cast made through the casting facility according to an embodiment of the present invention, the cast is produced through a mold having a thickness of up to 800mm and a width of 2000mm. Thus, it can be seen that the cast steel of the embodiment is produced with an initial thickness of 800 mm, and after the forging and rolling process, finally has a thickness of 178 mm. In addition, in the cast steel of the embodiment, the casting equipment is separated into a casting part and a solidification part, and a process for preventing the pre-solidification of the upper part of the casting part in the solidification part, it can be confirmed that the real rate of the cast steel has 89%.

As described above, the slab of the Example has a substantially higher rate of error of about 40% compared to the slab of Comparative Example 1, and has a thickness suitable for the cast steel for ultra-thick steel compared to the slab of Comparative Example 2. That is, the cast steel produced using the equipment of the embodiment can solve the problems of the cast steel produced through ingot casting and conventional continuous casting.

In addition, the ultra-thick steel material produced according to the embodiment did not observe surface defects (eg, corner cracks) that can be visually observed, and the macro quality was also achieved by applying molten steel stirrer in the slab to achieve 100% isotropic rate. Occurrence of segregation was not observed. Therefore, it can be seen that the quality of the ultra-thick steel produced by applying the embodiment of the present invention is improved.

As described above, according to an embodiment of the present invention, the continuous casting equipment is divided into a casting part and a solidification part, the cast is completed in the casting part is transferred to the solidification part, and after the solidification of the cast in the solidification part is transferred to the post-process It is easy to manufacture ultra-thick steel and can improve the quality and error rate of the final cast.

More specifically, after casting the cast from the casting portion to the solidification unit, the solidification unit to complete the solidification of the cast through the first quality controller and to suppress or prevent the pre-solidification of the upper portion of the cast to reduce the formation of the pipe It can improve the quality of the convenience. As a result, due to the improvement of the quality of the cast, it is possible to improve the error rate of the cast because it does not perform unhealthy part cutting which is a problem of ingot casting.

In addition, while the cast is transferred to the solidification portion, while the solidification in the solidification portion, the casting portion can be cast in the later cast iron can solve the problem of the conventional batch process such as ingot casting. As a result, it is possible to increase the productivity of the cast steel. And the cast slab produced at the end of the casting process is not transferred to the solidification unit, it is possible to complete the solidification through the second quality controller provided in the casting unit. Thus, the efficiency of the process can be increased.

Although the invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the invention is not limited thereto, but is defined by the claims that follow. Accordingly, one of ordinary skill in the art may variously modify and modify the present invention without departing from the technical spirit of the following claims.

S: Casting 1: Casting Equipment

1a: casting part 1b: solidification part

100: accommodating part 200: drawing machine

300: second quality controller 320: stirring unit

340: second heater 400: pusher

500: support portion 600: first quality controller

620: first stirrer 640: second stirrer

660: first heater 700: feeder

Claims

A casting part for forming a passage through which molten steel passes and casting the molten steel into cast steel;

A support part spaced apart from the casting part to receive the cast steel from the casting part, the support part being disposed on at least one of the side surfaces of the cast steel to support the cast steel, and provided at an outer side of the cast steel to induce solidification of the cast steel. Casting equipment comprising a solidification unit is provided;
The method according to claim 1,

The first quality controller comprises a first stirrer disposed proximate to the outside of the cast steel to move up and down in the longitudinal direction of the cast steel;

A second stirrer spaced below the first stirrer and capable of lifting up and down in the longitudinal direction of the cast steel; And

And a first heater installed to be able to move back and forth to the upper region of the cast steel, and heating the upper portion of the cast steel.
The method according to claim 2,

The first stirrer is casting equipment in which a coil wound around the cast piece is arranged in a circular shape.
The method according to claim 1,

The casting part,

An accommodation portion having a space in which the molten steel is accommodated;

A drawer for drawing the cast piece downward from the accommodation portion;

Casting equipment comprising a; second quality controller provided on the outside of the passage.
The method according to claim 4,

The receiving portion,

And a mold forming a path through which the molten steel supplied to the tundish passes, wherein the mold is formed such that the cast steel has a thickness of 800 mm or less and a width of 2000 mm or less.
The method according to claim 4,

The second quality controller,

A stirring unit disposed outside the mold and including at least one stirrer for stirring at least one of the molten steel and the unsolidified molten steel in the cast steel; And

And a second heater installed to be able to move back and forth to the lower portion of the mold and to heat the upper portion of the cast steel.
The method according to claim 6,

The stirring unit is disposed in close proximity to the mold, the third stirrer capable of lifting in the drawing direction of the cast steel;

And a fourth stirrer spaced below the third stirrer and capable of lifting up and down in the drawing direction of the cast steel.
The method according to claim 7,

The third stirrer is a casting facility in which a coil wound around the mold or around the cast piece is disposed in a circular shape.
The method according to claim 1,

The casting unit is provided with a pusher for separating the cast from the drawer, the pusher is installed to be reciprocating forward and backward toward the solidification unit.
The method according to claim 1,

And a feeder for transferring the cast steel from the casting portion to the solidification portion or for transferring the cast steel from the solidification portion to the outside of the solidification portion.
As the casting method,

Preparing molten steel to prepare a casting;

Casting the molten steel in a casting part to open and close a passage through the molten steel;

Transferring the cast steel produced through the casting to a solidification part; Including,

After the solidification of the cast steel is completed, the casting method for transferring the cast steel to a later step.
The method according to claim 11,

Casting of the molten steel in the casting part after transferring the cast steel to a solidification part.
The method according to claim 12,

If the process of casting the molten steel is repeated,

The process of transferring the cast steel to the solidification unit, the casting method is performed while the molten steel is transferred to the casting unit to prepare the casting.
The method according to claim 11,

In the case of the yeonyeonju casting the molten steel is a one-time casting, the cast is a casting method of completing the solidification in the casting portion or after being transferred to the solidification portion to complete solidification.
The method according to claim 11,

The molten steel is cast at a circumferential speed of 0.3 m or less per minute.