KR101767935B1

KR101767935B1 - Device for Removing Defect of Slab, Casting Apparatus having the same, and Casting Method

Info

Publication number: KR101767935B1
Application number: KR1020150158094A
Authority: KR
Inventors: 조운관; 문기현; 김흥섭; 우정화
Original assignee: 주식회사 포스코
Priority date: 2015-11-11
Filing date: 2015-11-11
Publication date: 2017-08-14
Also published as: KR20170055205A

Abstract

The present invention relates to an image forming apparatus comprising a frame which is located on a moving path of an object to be processed and extends so as to surround at least two sides of the object to be processed, a first drive unit movably provided along the extending direction of the frame, A second drive unit mounted on the drive unit so as to be able to move up and down; and a removal unit provided on the second drive unit for melting a defect-generating portion of the object to be processed, The unit can be moved quickly and accurately to easily remove defects.

Description

Technical Field [0001] The present invention relates to a defect remover, a casting apparatus having the same, and a casting method,

The present invention relates to a defect remover, a casting apparatus having the same, and a casting method. More particularly, the present invention relates to a defect remover capable of easily removing defects by moving a removal unit quickly and accurately to a position where defects And a casting method.

In general, a continuous casting process is a continuous casting process in which a molten steel is continuously injected into a mold, and the molten steel which has been reacted in the mold is continuously drawn downwardly of the mold to produce slabs of various shapes such as slabs, blooms, billets, .

At this time, the quality of the cast steel is evaluated according to the degree of defects such as pin holes or cracks occurring on the surface and edge of the cast steel. Accordingly, it is possible to improve the quality of the final cast product by performing a process of removing defects formed in the cast product.

The process of removing defects in cast steel may improve the economics associated with the economics of cast steel production according to the method and technique. Therefore, in the past, a technique for removing defects of the cast steel through a scarfing method using an oxygen torch has been used as a method for removing defects of cast steel.

The scarping method is a method in which a defective portion on a cast steel is melted with an oxygen torch and then removed. However, in order to remove defects after melting the surface of the cast steel, a process is required in which only a part of the cast steel where the defect occurs is spun (cut) or the entire area of the cast steel is spun. Therefore, the loss of the cast steel can be increased due to the spindle milling. Also, the cumulative amount of loss of the casting can increase the economic loss.

KR 2012-0107345 A

The present invention provides a defect remover, a casting apparatus having the defect remover, and a casting method that can remove defects easily by moving a removal unit quickly and accurately to a position where a defect of the casting has occurred.

The present invention provides a defect remover, a casting apparatus having the same, and a casting method capable of suppressing or preventing loss of casting due to spitting.

The present invention relates to a frame, which is positioned on a moving path of an object to be processed and extends so as to surround at least two sides of the object to be processed; A first driving unit movably installed along an extending direction of the frame; A second drive unit mounted to the first drive unit so as to be able to move up and down; And a removing unit installed in the second driving unit for melting a defect-generating portion of the object to be processed; .

The frame includes a first straight section extending in the width direction of the article to be processed and located on the upper side of the article to be processed, a second straight section extending in the width direction of the article to be processed and positioned on the lower side of the article to be processed, And a curve section connecting the first straight line section and the second straight line section.

And a sensor unit installed in either the removal unit or the second drive unit to measure a distance between the removal unit and the object to be processed.

A plurality of removing units are provided to simultaneously remove a plurality of defects formed on different portions of the object to be processed.

Further comprising a control unit for performing at least one of an operation of controlling the operation of the first drive unit to adjust the position of the removal unit and an operation of controlling the operation of the second drive unit in connection with the sensor unit do.

The removal unit includes a plasma torch for locally fusing defective portions of the casting.

A mold into which molten steel is injected; And a plurality of conveying rollers located below the mold and forming a movement path of the casting to be withdrawn; A cutter positioned on the movement path of the casting and cutting the casting material moving along the conveying roller; And a defect remover located on the path of the casting to remove defects passing through the cutter; .

And a defect detector positioned between the cutter and the defect remover to detect defects in the casting.

The defect detector includes at least one of an optical sensing unit or an electromagnetic sensing unit.

The present invention relates to a process for casting a cast steel by injecting molten steel into a casting mold; Cutting the slab moving along the moving path; Inspecting at least two sides around the slab; Melting the part where the defect is generated and cooling the part when the defect is found on the surface of the casting; .

The process of melting the defective portion and then cooling the defective portion includes simultaneously removing a plurality of defects.

The process of melting the defective portion and then cooling the defective portion may include locally melting the defective portion.

The process of locally melting the defective portion may include melting the defective portion to a depth of 2 to 10% of the entire thickness of the castellum.

Wherein the defect comprises cracks or pinholes,

The process of melting the defective portion and then cooling the defective portion includes a step of spraying the plasma flame to the defective portion.

According to the embodiments of the present invention, it is possible to remove the defective portion of the casting by the removal unit movable along the periphery of the cast steel. That is, the removal unit can quickly move into defects that occur at various locations. Thus, regardless of where the defect occurs, the removal unit can be moved accurately to the position where the defect occurred, and the defect of the casting can be easily removed.

Further, the portion where the defect of the casting has been generated can be removed without sparging. That is, the defective portion can be rapidly melted and then cooled to remove defects. Therefore, it is possible to suppress or prevent the loss of the main body due to the spun. Thus, it is possible to reduce the economic loss due to the accumulated loss of the cast steel.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of the structure of a casting apparatus according to an embodiment of the present invention.
2 is a perspective view showing a defect remover according to an embodiment of the present invention;
3 illustrates operation of a defect remover in accordance with an embodiment of the present invention.
4 illustrates a defect remover in accordance with another embodiment of the present invention.
5 is a flowchart illustrating a casting method according to an embodiment of the present invention.
FIG. 6 is a photograph showing defects before and after the removal of defects in the casting according to the embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. To illustrate the invention in detail, the drawings may be exaggerated and the same reference numbers refer to the same elements in the figures.

2 is a perspective view illustrating a defect remover according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a defect remover according to an embodiment of the present invention. FIG. 4 is a view showing a defect remover according to another embodiment of the present invention, FIG. 5 is a flowchart showing a casting method according to an embodiment of the present invention, and FIG. Showing before and after the defects of the casting according to the example are removed.

1, a casting apparatus according to an embodiment of the present invention includes a casting mold 20 for casting molten steel, a plurality of casting rolls 20, which are located below the casting mold 20, A cutter 40 disposed on the movement path of the slab S for cutting the slab S moving along the feed roller 35; A defect detector (200) for detecting a defect of a slab (S), comprising a defect remover (100) positioned on a moving path of the slab (S) to remove a defect of the slab ).

The mold 20 may be a frame for determining the appearance of the gold product by solidifying the molten steel. The mold 20 has a pair of structurally opposed surfaces opened to form a hollow portion for receiving the molten steel supplied from the nozzle 15 of the tundish 10 arranged on the upper side. A cooling passage through which the cooling water can move can be formed inside the wall surface of the mold. Accordingly, the molten steel supplied into the mold 20 can be produced as the heat energy is taken up by the cooling water moving through the cooling channel and solidified.

The cooling stand 30 is disposed on the lower side of the mold 20. The cooling bed 30 is provided with a plurality of conveying rollers 30 arranged continuously to perform a series of forming operations while cooling the unfrozen casting S by forming a movement path of the casting S to be drawn to the lower portion of the casting mold 20, (35). In addition, a spray nozzle (not shown) for spraying cooling water on a part of the movement path of the slab S may be provided for quickly solidifying the slab S. Thus, the cast steel S can be solidified by injecting cooling water onto the upper and lower surfaces of the cast steel S and spraying cooling water on both sides of the cast steel S as well.

The cutter 40 is disposed on the upper part of the cast steel S and serves to cut the cast steel S passing through the lower part to a size desired by the operator. The cutter 40 is provided with a cutter body movably installed along the movement path of the slab S and a pair of sliders 40a and 40b which are provided movably in the width direction of the slab S on the front or rear face of the cutter body Cutting torch. Thus, it is possible to perform the operation of cutting the slab S by the cutting torch while moving the slab body in accordance with the speed of the slab S moving by the feed roller.

The defect detector 200 may be located between the cutter 40 and the defect remover 100. The defect detector 200 can sense defects of the billet S moving at least at any two positions of the upper side, the lower side, and the side of the bill S, and moving along the bill. That is, the defect detector 200 can inspect more than two sides around the slab S. During the continuous casting process, defects such as pin holes or cracks may occur on the surface, top, bottom, sides, and edges of the cast steel. Accordingly, it is possible to detect the occurrence of a defect and the position of a defect through the defect detector 200.

For example, the defect detector 200 may include an optical sensing unit. The optical sensing unit may include a light and a camera. Thus, when the light illuminates the surface of the cast steel S, light can be reflected from the surface of the cast steel S to the camera. Therefore, the surface image of the slab S can be photographed by the camera, and the surface of the slab S photographed through the camera can be observed to detect the occurrence of the defect and the position of the defect.

Alternatively, the defect detector 200 may include an electromagnetic sensing unit. The electromagnetic sensing unit may include a magnet for generating a direct current organs and a coil for generating an alternating electric field at the bottom of the magnet. Therefore, ultrasonic waves can be generated by the interaction between the magnetic field formed by the magnets on the surface of the cast steel and the alternating electric fields formed by the coils. By analyzing the ultrasonic waves, the presence or absence of defects and the position of the defects are detected can do.

As such, the defect detector 200 may include at least one of an optical sensing unit or an electromagnetic sensing unit. However, the method of detecting the structure or defect of the defect detector 200 is not limited to this and may be various.

The quality of the cast slab S is evaluated according to the degree of defects. If defects of the slab S are found by the defect detector 200, the defects formed in the slab S may be removed to improve the quality of the final slab product. Only a part of the cast slab S on which defects have occurred has been cut or the whole area of the slab S has been spun. However, there is a problem that the loss of the slab S is increased due to the spun of the slab S. Therefore, the defect remover 100 according to the embodiment of the present invention can be provided to remove defects in the slab S.

Referring to FIGS. 2 and 3, the defect remover 100 according to the embodiment of the present invention includes a frame (not shown) disposed on a moving path of an object to be processed and extending to cover at least two sides of the object to be processed A first driving unit 120 installed to be movable along an extension direction of the frame 110, a second driving unit 130 installed up and down by the first driving unit 120, And a removal unit (140) installed in the second drive unit (130) so as to melt the defective portion of the object to be processed. The sensor (140) measures a distance between the object to be processed and the removal unit Unit 150 and a control unit 160 for controlling the operation of the first driving unit 120 and the second driving unit 130. [ At this time, the material to be processed may be a cast slab (S).

The frame 110 includes a first straight section 111 extending in the width direction of the cast steel S and located on the upper side of the cast steel S and a second straight section 111 extending in the width direction of the cast steel S, A second straight section 113 positioned below the first straight section 111 and a curved section 112 connecting the first straight section 111 and the second straight section 113. That is, the frame 110 is formed so as to enclose only the upper surface, the lower surface, and the one side of the slab S, and thus the three sides of the slab S can be wrapped. At this time, the moving direction of the slab S may be the forward and backward direction, and the width direction of the slab S may be the leftward and rightward direction crossing the forward and backward directions.

The first straight section 111 may extend in the width direction of the slab S or in the direction intersecting the moving direction of the slab S. That is, the first straight line section 111 may be formed as a straight line frame. The first straight section 111 may be spaced apart from the upper side of the slab S and the extension length of the first straight section 111 may be equal to or greater than the width of the slab S. [ The removal unit 140 moved along the first straight section 111 can move to any position in the width direction of the slab S from above the slab S. [ Thus, defects occurring on the upper surface of the slab S can be easily removed while the removal unit 140 moves along the first straight section 111. [

The second straight section 113 may extend in the widthwise direction of the slab S or in the direction intersecting the moving direction of the slab S. That is, the second straight line section 113 may be formed as a straight line frame. The second straight section 113 may be spaced apart from the lower side of the slab S and the extension length of the second straight section 113 may be equal to or greater than the width of the slab S. [ The removal unit 140 moved along the second straight section 113 can move to any position in the width direction of the slab S from below the slab S. [ Accordingly, the removal unit 140 moves along the second straight line section 113, and defects occurring on the lower surface of the slab S can be easily removed.

The second straight section 113 may be positioned between the two conveying rollers 35 and the height of the upper surface of the second straight section 113 may be lower than the height of the upper surface of the conveying roller 35. Therefore, the billet S moving along the conveying roller 35 can pass between the first straight section 111 and the second straight section 113, and the elimination unit 140 can pass the first straight section 111 And the slab S passing through the second straight line section 113. In this case,

One end of the curved section 112 is connected to one side of the first straight section 111 and the other end is connected to one side of the second straight section 113. The curved section 112 may be formed in a U-shape, and may be disposed to surround the side surface of the slab S. For example, the curved section 112 may have one end connected to the left side of the first straight section 111 and the other end connected to the left side of the second straight section 113. Thus, defects occurring at the edge portion of the slab S can be easily removed while the removal unit 140 passes the left edge portion of the slab S. [

The first driving unit 120 may be mounted on the outer periphery of the first rectilinear section 111, the second rectilinear section 113 and the curved section 112 to form a rail 115 capable of moving . Accordingly, when the first drive unit 120 moves along the rail 115, the removal unit 140 can move together with the first drive unit 120. [ The removal unit 140 moves along the extension direction of the frame 110 to any position around the slab S such as the upper surface, the side surface, and the lower surface of the slab S, Can be removed.

At this time, the right side of the first rectilinear section 111 and the right side of the second rectilinear section 113 can be opened. That is, the path through which the removal unit 140 moves can be opened. Therefore, the first driving unit 120 can be put on the right side of the first straight line section 111 or the right side of the second straight line section 113, and can be placed on the rail 115. Accordingly, the first driving unit 120 can be easily installed or removed from the frame 110. If the first driving unit 120 is broken, the first driving unit 120 can be separated from the frame 110 and easily repaired or replaced.

In addition, the slab S can be manufactured in various shapes such as various shape slabs, blooms, billets, beam blanks and the like. That is, the cast steel S may be formed in various sizes depending on its shape. Therefore, if the frame 110 is formed so as to surround the whole circumference of the slab S, the distance between the both sides of the slab S and the removal unit 140 may vary depending on the kind of the slab S to be produced. Thus, when the cast steel S having a width greater than the width of the frame 110 is produced, the cast steel S may not pass through the frame 110.

On the other hand, when one side of the frame 110 is opened, the cast steel S can stably pass through the frame 110 even if the cast steel S having a large width is produced. Thus, the continuous casting process can be performed stably without interruption, and defects generated in the cast steel S can be easily removed. However, the structure and the shape of the frame 110 are not limited to this, and may be formed so as to surround the entire circumference of the slab S.

The first drive unit 120 may be movably installed on the rails of the frame 110. [ Accordingly, the first driving unit 120 can move around the slab S along the extending direction of the frame 110. [ That is, the first driving unit 120 can move in the width direction or the left and right direction of the slab S from above and below the slab S through the first straight section 111 and the second straight section 113 , And can move on the side of the slab S through the curved section 112.

Also, the first driving unit 120 serves to support the second driving unit 130 and the high removal unit 140. Therefore, the removal unit 140 can move around the slab S along the first drive unit 120. [ Thus, the removal unit 140 can easily move to the position where the defect of the slab S occurs.

For example, the first drive unit 120 may include a drive wheel that moves along the rail 115 and a motor that rotates the drive wheel. Thus, the operation of the motor can be controlled to move the first drive unit 120 on the rails 115. However, the manner in which the first drive unit 120 moves is not limited to this and may vary.

The second drive unit 130 is installed on the first drive unit 120 so as to be movable up and down. Accordingly, the second driving unit 130 can control the distance between the second driving unit 130 and the slab S while moving up and down. Also, the second drive unit 130 may be provided with a removal unit 140. Therefore, when the second drive unit 130 is moved up and down, the removal unit 140 can move together. Thus, the operation of the second driving unit 130 can be controlled to adjust the separation distance between the slab S and the removal unit 140.

If the separation distance between the removal unit 140 and the slab S is adjusted as described above, the depth at which the removal unit 140 is melted can be adjusted. That is, when the distance between the removal unit 140 and the cast steel S is increased, the area of the flame injected from the removal unit 140 in contact with the cast steel S decreases, and the steel can be melted only to a lower depth. On the contrary, when the distance between the removal unit 140 and the cast steel S becomes close to each other, the area of the flame injected from the removal unit 140 in contact with the cast steel S increases and the steel can be melted to a deep depth.

For example, the second drive unit 130 may include a motor, and some of the second drive unit 130 may move up and down by the operation of the motor. Alternatively, the cylinder may be provided so that the rod portion can move up and down. Accordingly, the removal unit 140 can be connected to the vertically moving part of the second drive unit 130, and the distance between the removal unit 140 and the slab S can be adjusted. However, the manner in which the second drive unit 130 is lifted and lowered is not limited to this and may vary.

The removal unit 140 can quickly remove the defective portion of the slab S and then cool it to remove defects. For example, the removal unit 140 may be a plasma torch that locally fuses the defect occurrence region of the slab S. Thus, the removal unit 140 may include a gas supply part for supplying gas and an electrode part for generating plasma through discharge. Therefore, when a gas is supplied and a plasma jet is generated through an arc discharge, a plasma flame can be generated.

When such a plasma flame is sprayed to a portion where defects of the slab S are generated, the defective portion can be momentarily melted and then cooled. The defects such as cracks and pinholes can be burnt by melting, plasma flame, and the defects can be completely removed while being cooled. Therefore, the portion where the defect of the cast steel S is generated can be removed without cutting.

At this time, the removal unit 140 can locally melt only the region where the defect of the slab S is generated without cutting the slab S. For example, the removal unit 140 can only melt to a depth of 2 to 10% of the thickness of the slab S. Generally, the thickness of the cast slab S to be produced is about 250 mm, and the depth of cracks and pinholes generated in the slab S is mostly 7 mm or less. That is, cracks or pinholes may be generated at a depth of 2 to 3% of the thickness of the cast steel (S). Therefore, it is necessary to melt the cast steel S to a depth greater than the depth of the defect to remove the defects.

That is, if a portion where the defect of the billet S is generated at a depth smaller than the depth of the defect is melted, cracks or pinholes can not be completely removed from the inside of the bill S, so that a void space can be formed. Therefore, in order to completely remove defects, it is necessary to melt regions having a larger area and a larger depth than defects. Therefore, it is necessary to melt the portion where the defect of the slab S is generated to a depth of at least 2% of the thickness of the slab S.

However, if the plasma flame is melted to the depth of the slab S, the crystal structure of the slab S may be changed or the amount of fume generated may increase. Or a problem that the slab S is cut by melting too deep may occur. Therefore, since the defects are removed by melting to only 10% or less of the thickness of the slab S with the removal unit 140, the crystal structure of the slab S is changed, the fume is generated or the slab S is cut, can do. However, the method of melting the defective portion of the slab S by the removal unit 140 is not limited to this, and may vary.

The sensor unit 150 is provided in the removal unit 140 or the second drive unit 130 to measure the separation distance between the removal unit 140 and the slab S. [ For example, the sensor unit 150 may be installed in the second drive unit 130 and positioned next to the removal unit 140. The sensor unit 150 can measure the separation distance between the end pieces S and the end pieces S thereof. Therefore, if the distance between the end of the sensor unit 150 and the end of the removal unit 140 is subtracted from the value measured at the sensor unit 150, the distance between the removal unit 140 and the casting S Can be calculated.

That is, the sensor unit 150 can indirectly measure the distance between the removal unit 140 and the cast steel S. At this time, the sensor unit 150 can move up and down together with the removal unit 140. However, the method of measuring the distance between the removal unit 140 and the cast steel S by the sensor unit 150 is not limited to this and may vary.

The control unit 160 controls the operation of the first drive unit 120 to adjust the position of the removal unit 140 and the operation of controlling the operation of the second drive unit 130 in connection with the sensor unit 150 Or the like. The control unit 160 is connected to the defect detector 200 and the sensor unit 150 and includes a transceiver 161 transmitting and receiving the defect information of the slice S and the position information of the elimination unit 140, The comparison unit 162 compares the position information of the first driving unit 120 with the position information of the first driving unit 120 and the predetermined setting value, (Not shown).

The transceiver unit 161 may be connected to the defect detector 200 and the sensor unit 150. Thus, the transceiver unit 161 can obtain the positional information of the defect generated on the surface of the slab S from the defect detector 200. The transmission / reception unit 161 can also obtain the separation distance information between the slab S and the removal unit 140 from the sensor unit 150.

The comparing unit 162 is connected to the transmitting / receiving unit 161 and receives the distance information between the slab S and the removing unit 140 and compares the distance information with a predetermined set value. At this time, the set value may be a value of the separation distance between the slab S and the removal unit 140 desired by the operator. Accordingly, the comparison unit 162 can compare whether the actual distance value between the cast steel S and the removal unit 140 measured by the sensor unit 150 is equal to or different from the set value.

The control unit 163 is connected to the transmission / reception unit 161 to control the operation of the first driving unit 120 so that the removal unit 140 moves to a position where defects of the slab S are generated. Therefore, the removal unit 140 can quickly move to the defect occurrence portion, thereby accurately removing the defect occurrence portion.

The control unit 163 controls the operation of the second driving unit 130 when the actual distance value between the slab S and the removal unit 140 is different from the set value by being connected to the comparison unit 162, The position of the removal unit 140 can be adjusted so that the value measured by the unit 150 becomes equal to the set value. Therefore, even if the width of the cast steel S varies, the removal unit 140 can be maintained in a state of being always spaced apart from the steel strip S by the set value. Thus, only the region where the removal unit 140 has a certain depth and the defect of the slab S has occurred can be locally removed.

Meanwhile, a plurality of removing units 140 may be provided to simultaneously remove a plurality of defects formed on different portions of the cast S, respectively. For example, as shown in FIG. 4, three removal units may be provided, that is, a first removal unit 140a, a second removal unit 140b, and a third removal unit 140c. The first removal unit 140a moves along the first straight section 111 of the frame 110 while the second removal unit 140b moves along the curved section 112 of the frame 110, And the third removal unit 140c can move along the second straight line section 113. [ At this time, the first drive unit 120 and the second drive unit 130 may also be provided with a plurality of the number of the removal units 140 to move the removal units 140 individually.

The first removing unit 140a removes defects generated on the upper surface of the cast steel S and the second removing unit 140b removes defects generated on the edge portion and the side surface of the cast steel S, The removal unit 140c can remove defects generated on the lower surface of the cast steel. Thus, a plurality of defects generated at different positions of a plurality of removal units can be simultaneously removed. Therefore, the defects generated in the slab S can be quickly removed, and the efficiency of the process can be improved.

At this time, the control unit 160 can move the removal units while monitoring the position of each of the removal units. Therefore, it is possible to prevent the removal units from colliding with each other during the operation. However, the number of the removal units, the positions where the removal units are provided, and the movement ranges of the removal units may be various and not limited thereto.

As described above, the removal unit 140, which can move along the periphery of the slab S, can remove the defective portion of the casting. That is, the removal unit 140 can quickly move to the defects of the cast S generated at various positions. Therefore, regardless of the position where the defect occurs, the removal unit 140 can accurately move to the position where the defect occurs, and the defect of the cast S can be easily removed.

Further, the portion where the defect of the cast steel S is generated can be removed without sparging. That is, the defective portion can be rapidly melted and then cooled to remove defects. Therefore, it is possible to suppress or prevent the loss of the slab S due to the sparging. Thus, the economic loss due to the accumulated loss of the slab S can be reduced.

Hereinafter, a casting method according to an embodiment of the present invention will be described in detail.

Referring to FIG. 5, the casting process according to the embodiment of the present invention includes a process (S100) of casting a cast steel by injecting molten steel into the casting mold, a step (S200) of cutting a casting material moving along the movement path (S300) of inspecting at least two sides of the casting slab, and a step S400 of melting and cooling the defective portion when a defect is found on the surface of the casting slab (S400). At this time, the defect may include cracks or pinholes.

First, molten steel is supplied to the mold 20 and drawn downward. The cast slab S to be drawn is solidified while passing through the cooling stand 30 which forms a moving path of the slab S from the lower side of the casting mold 20. [ At this time, the cutter 40, the defect detector 200, and the defect remover 100 may be disposed on the movement path of the slab S.

The cutter 40 cuts the slab S passing through the lower side along the feed roller 35 to a predetermined size. The defect detector 200 can then inspect the perimeter of the slab S through the cutter 40. That is, it is possible to observe the surface of the cast steel S by observing each surface around the cast steel S, and to ascertain the position of the defect by checking whether a defect such as crack or pinhole has occurred on the surface of the cast steel S.

Then, if a defect is found, the removal unit 140, which can move to any position around the slab S, is moved to the defective portion of the slab S in accordance with the information detected by the defect detector 200 . The removal unit 140 can rapidly cool the portion where the defect is generated by spraying the plasma flame only in the region where the defect of the slip S has been generated. That is, the removal unit 140 can locally melt only the portion where the defect of the slab S is generated. Therefore, the portion where the defect is generated can be burnt instantly while being melted, .

For example, as shown in FIG. 6, the defects generated in the slab S can be removed through the removal unit 140. That is, as shown in Fig. 6 (a), cracks may occur on the surface of the cast steel S. In order to remove such cracks, it is possible to melt the cracks and the periphery of the cracks as shown in Fig. 6 (b), and to melt the portions deeper than the depth of the cracks. Accordingly, the entire cracked portion can be buried while the periphery of the crack is instantaneously melted. Thus, the crack can be completely removed while the crack solidifies.

At this time, the removal unit 140 can melt only to a depth of 2 to 10% of the thickness of the slab S. That is, when a portion of the slab S where a defect is generated at a depth smaller than the depth of the defect is melted, cracks or pinholes are not completely removed in the slab S, and a void can be formed in the slab S. Therefore, in order to completely remove the defects, it is necessary to melt the portion of the slab S where the defect is generated to a depth of 2% or more of the thickness of the minimum slab S.

However, if the plasma flame is melted to the depth of the slab S, the crystal structure of the slab S may be changed or the amount of fume generated may increase. Therefore, the defects are removed by melting to only 10% or less of the thickness of the slab S with the removal unit 140, so that the crystal structure of the slab S can be changed or fume can be suppressed or prevented.

On the other hand, a plurality of defects may be simultaneously removed by providing a plurality of removal units 140. That is, when a plurality of defects are generated in the cast steel S, a plurality of defects can be simultaneously removed by moving the plurality of removal units 140 to each of the defects. At this time, the first drive unit 120 and the second drive unit 130 may also be provided with a plurality of the number of the removal units 140 to move the removal units 140 individually. Therefore, the defects generated in the slab S can be quickly removed, and the efficiency of the process can be improved. Thus, defects formed in the cast steel S can be removed, and the quality of the final cast steel product can be improved.

Although the present invention has been described in detail with reference to the specific embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined by the appended claims, as well as the appended claims.

20: Mold 30: Cooling zone
100: Defect remover 110: Frame
120: first drive unit 130: second drive unit
140: removal unit 150: sensor unit
160: control unit 200: defect detector

Claims

A frame positioned on a moving path of the object to be processed and extending to cover at least two sides of the object to be processed;
A plurality of first driving units movably installed along an extending direction of the frame;
A plurality of second driving units mounted on the plurality of first driving units so as to be able to move up and down;
A plurality of removal units installed in the plurality of second drive units for melting defective portions of the object to be processed; And
And a control unit for controlling the movement of the plurality of removal units while monitoring a position of each of the plurality of removal units so as to prevent the plurality of removal units from colliding with each other while moving at the same time.

The method according to claim 1,
The frame includes a first straight section extending in the width direction of the article to be processed and located on the upper side of the article to be processed, a second straight section extending in the width direction of the article to be processed and positioned on the lower side of the article to be processed, And a curve section connecting the first straight line section and the second straight line section.

The method according to claim 1,
Further comprising a sensor unit installed in either the removal unit or the second drive unit so as to measure a separation distance between the removal unit and the object to be processed.

delete

The method of claim 3,
The control unit performs at least one of an operation of controlling the operation of the first drive unit to adjust the position of the removal unit and an operation of controlling the operation of the second drive unit in connection with the sensor unit Defect remover.

The method according to claim 1,
Wherein the removal unit comprises a plasma torch for locally fusing defective portions of the object to be treated.

A mold into which molten steel is injected;
And a plurality of conveying rollers located below the mold and forming a movement path of the casting to be withdrawn;
A cutter positioned on the movement path of the casting and cutting the casting material moving along the conveying roller; And
A defect remover according to any one of claims 1 to 3, claim 5, and claim 6 located on a traveling path of the casting to remove a defect of the casting passing through the cutter; Including casting equipment.

The method of claim 7,
Further comprising a defect detector positioned between said cutter and said defect remover to detect defects in said casting.

The method of claim 8,
Wherein the defect detector comprises at least one of an optical sensing unit or an electromagnetic sensing unit.

Providing a plurality of removal units movably installed along the circumference of the cast steel to melt the defective portion of the cast steel;
A process in which molten steel is injected into a mold to draw out the cast;
Cutting the slab moving along the moving path;
Inspecting at least two sides around the slab; And
A step of moving the removal unit to melt the defective part when the defect is found on the surface of the casting, and then cooling the defective part; Including,
Wherein the step of moving the removal unit includes moving and monitoring the position of each of the plurality of removal units so that the plurality of removal units do not collide with each other.

The method of claim 10,
The step of melting and cooling the defect-
And simultaneously removing a plurality of defects.

The method according to claim 10 or 11,
The step of melting and cooling the defect-
And locally melting the defective portion.

The method of claim 12,
The process of locally melting the defective portion may include:
And melting the defective portion to a depth of 2 to 10% of the entire thickness of the cast steel.

The method according to claim 10 or 11,
Wherein the defect comprises cracks or pinholes,
The step of melting and cooling the defect-
And spraying a plasma flame to the defective portion.