KR20110074153A - Apparatus for casting of vertical type and method for casting using it - Google Patents

Abstract

PURPOSE: A vertical casting device and casting method using the same are provided to enhance the quality of piece by preventing damage to the surface of a cooling mold using a fixed cooling mold. CONSTITUTION: A vertical casting device comprises a cooling mold(110), a support(130), a solidifying unit(170), a magnetic-filed applying unit(120) and a cooling unit. The cooling mold holds molten metals. The support supports pieces falling down the cooling mold. The solidifying unit is installed right under the cooling mold to cool the pieces. The magnetic-filed applying unit is vertically driven along the piece outside the cooling mold and agitates and induction-heats ingot steel and pieces. The cooling unit is vertically driven along the piece right under the solidifying unit.

Description

Apparatus for casting of vertical type and method for casting using it}

The present invention relates to a vertical casting apparatus and a casting method using the same. In particular, the present invention relates to a vertical casting apparatus for producing a large ingot as a stationary cooling mold and a casting method using the same.

Continuous casting injects molten steel into a mold of a certain shape, and continuously casts a cast specimen (hereinafter referred to as a 'casting') of molten steel reacted in the mold to the lower side of the mold, thereby slab and bloom. It is a casting method for producing semi-finished products of various shapes such as bloom, billet and the like.

In addition, semi-continuous casting, which is distinguished from this, is used when the size of the cast is large and continuous casting is difficult, and a certain amount of cast steel is periodically injected from the mold and a certain amount of molten steel is injected semi-continuously. It is a casting method for producing a semi-finished product by drawing.

Looking at the conventional vertical casting apparatus using a semi-continuous casting method with reference to FIG. 1 is a view showing a vertical casting apparatus according to a conventional embodiment.

In the conventional vertical casting apparatus, molten steel is introduced into a mold 10 from a tundish (not shown), and the cast steel S drawn from the mold 10 is provided under the mold 10. It solidifies while passing through the roll 70 and the cooling nozzle 80. At this time, the lower end of the cast (S) is coupled to a plate (well block or well plate) 32 or a dummy bar (dummy bar) to support the cast (S), by the surface plate driving means 30 of the cast (S) It is driven up and down along the drawing direction.

Such a conventional vertical casting apparatus is provided with a heating device 90 for heating the top portion (the uppermost end of the cast in the longitudinal direction) of the cast (S) to prevent the solidification of the cast (S) cast (S) Shrinkage). To this end, conventionally, the upper portion of the cast (S) to raise the cast steel (S) that was drawn to the lower side of the mold 10 so as to be located inside the heating cover 96, the inside of the heating cover 96 is inert gas atmosphere The top of the slab S was heated by an arc or plasma P by using the gas injection tube 94 and the electrode 92 formed in the furnace.

However, the conventional vertical casting apparatus as described above raises the cast steel (S) that is drawn, so that the surface of the mold 10 is easily damaged and the quality of the cast steel (S) is degraded, and the heating device on the upper portion of the mold (10) There was a problem in that the columnar space was narrowed due to the location of (10).

In addition, since the cast steel S cast in the vertical casting apparatus is large in size, the cast steel S immediately after passing through the cooling nozzle 80 has the straight surface of the outer surface and the surface plate 32 in the solidified state (part B). Unlike the upper part (the tip of the cast), there is a liquid molten steel in an unsolidified state (site A). Conventionally, a means for cooling the slab S passing through the cooling nozzle 80 is not provided, and re-heating by the unsolidified liquid molten steel causes a problem of re-dissolving the distal end portion of the slab S. Accordingly, in the course of the solidification of the cast steel (S), temperature imbalance is caused in the longitudinal direction of the cast steel (S), which causes the solidification discontinuous layer (A '; see Fig. 2 (a)) or voids inside the cast steel (S) There was a problem that the defects were caused to deteriorate the quality of the cast (S). (Here, FIG. 2 (a) is a diagram schematically showing the internal state of the slab on which the solidification discontinuous layer is formed, and FIG. 2 (b) is a diagram schematically showing the inner state of the slab on which the solidification continuous layer is formed.

On the other hand, in the conventional vertical casting apparatus, when the slab S that has been solidified is separated from the surface plate 32, a part of the slab S is forcibly separated by using a cutting torch or the like, and thus the operation convenience is inferior. There was a problem that the error rate of S) is lowered.

The present invention provides a vertical casting apparatus and a casting method using the same for producing a large ingot as a stationary cooling mold.

The present invention provides a vertical casting apparatus and a casting method using the same, which can continuously cool the cast steel by having a magnetic field applying unit for stirring and induction heating the cast steel.

The present invention provides a vertical casting apparatus and a casting method using the same, having a cooling unit capable of cooling the front end of the cast steel to suppress reheating generated inside the cast steel.

The present invention provides a vertical casting apparatus having a separation unit and a rotation transfer unit capable of automatically separating and transferring the solidified cast piece on the surface plate and a casting method using the same.

Vertical casting apparatus according to an embodiment of the present invention is a cooling mold into which molten steel is introduced, a support for supporting the cast steel drawn to the lower side of the cooling mold, and a solidification unit provided under the cooling mold to cool the cast steel And driven up and down along the cast steel outside the cooling mold, and driven up and down along the cast steel directly under the magnetic field applying portion and the solidification portion to stir and induce heating the molten steel and the cast steel to cool the cast steel. It includes a cooling unit.

In addition, the vertical casting device is provided on one side of the slab and the separating portion for pushing the cast to separate from the support portion, and the other side of the slab facing the separating portion is provided to rotate and rotate the horizontal cast It further comprises a transfer unit.

On the other hand, in the vertical casting method according to an embodiment of the present invention, the step of inserting the surface plate of the support to the lower portion of the cooling mold, introducing the molten steel into the cooling mold, and using a magnetic field applying portion outside the cooling mold Stirring and induction heating the molten steel, drawing the slab to the lower side of the cooling mold while lowering the surface plate, and passing the slab to a solidification unit provided directly below the cooling mold, and the magnetic field Stirring and induction heating the slab passed through the solidification unit by moving the application unit and driving the cooling unit up and down along the slab directly under the solidification unit to cool the slab.

In the vertical casting method, after solidification of the slab is completed after the step of cooling the slab using the cooling unit, the slab is pushed from one side to separate from the support, and the separated slab is rotated horizontally. And cutting the conveyed cast pieces to a predetermined length.

According to embodiments of the present invention it is possible to improve the quality of the cast by preventing the surface damage of the cooling mold using a fixed cooling mold.

In addition, the top portion of the molten steel flowing into the cooling mold and the cooling mold can be continuously cooled along the longitudinal direction by stirring and induction heating using a magnetic field applying portion. That is, the quality of the cast can be improved by preventing the solidification discontinuity layer or voids from occurring in the cast.

In addition, it is possible to prevent the temperature imbalance due to reheating generated in the interior of the slab by having a cooling unit for continuously cooling the front end portion of the slab during the drawing and solidification process. That is, it is possible to prevent defects such as solidification discontinuity layers and voids inside the cast, thereby reducing the defective rate of the cast.

In addition, it is possible to easily separate the cast slab after solidification from the surface plate to facilitate the operation process, it is possible to improve the error rate of the cast.

Therefore, the vertical casting apparatus and the casting method using the same according to the embodiments of the present invention can improve the productivity of the process of producing a large ingot (cast).

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention to complete the disclosure of the present invention, to those skilled in the art It is provided to fully inform the category. Like reference numerals in the drawings refer to like elements.

Figure 3 is a view showing the configuration of a vertical casting apparatus according to an embodiment of the present invention, Figure 4 is a view showing the configuration of a vertical casting apparatus according to another embodiment of the present invention, Figure 5 is a view of the present invention 6 is a view showing a cooling unit according to an embodiment, FIG. 6 is a view showing a state in which a heating insulation unit is coupled to a vertical casting apparatus according to embodiments of the present invention, Figures 7 to 9 are embodiments of the present invention A graph and a state diagram showing an experimental example of a vertical casting apparatus according to the present invention. (Hereinafter, the casting apparatus will be described with reference to a vertical casting apparatus using a semi-continuous casting method. Also, an embodiment of the present invention will be described first, and then another embodiment of the present invention will be described with an embodiment. The explanation focuses on the differences between.)

3 to 9, the vertical casting apparatus 100 according to an embodiment of the present invention includes a fixed cooling mold 110 in which molten steel (M) flows inward and is primarily cooled. Support portion 130 for supporting the cast steel (S) drawn to the lower side of the mold 110, a solidification unit 170 provided below the cooling mold 110 to cool the slab (S) secondary, and the cooling mold Driven up and down along the cast (S) from the outside of 110, directly below the magnetic magnetic stirrer (120) and the solidification unit 170 for stirring and induction heating the molten steel (M) and cast (S) In the upper and lower driving along the cast (S) includes a cooling unit (bottom water spray cooling (BWSC); 180) for tertiary cooling the cast (S).

In addition, the vertical casting device 100 according to an embodiment of the present invention is provided on one side of the slab (S) and separated from the separation unit 140 for pushing one side of the slab (S) to separate from the support portion 130, Rotating feeder 150 which is provided on the other side of the slab (S) facing the portion 140 and rotates and horizontally transporting the cast (S), and a cutting portion for cutting the horizontally transported cast (S ') to a predetermined length ( 160).

The cooling mold 110 is a vertically perforated rectangular frame that solidifies in a predetermined form by passing the molten steel M in a liquid state. The cooling mold 110 used in the embodiments of the present invention is always formed in a constant cross-sectional area of the cast (S) drawn to the lower side of the cooling mold 110 by using a fixed mold that does not deform the form of the frame. do. Here, the shape of the cooling mold 110 can be freely deformed according to the shape, size of the cast (S) to be produced.

On the other hand, the cooling mold 110 is a water-cooled mold (water-cooled mold) is provided with a cooling water pipe (not shown) through which the cooling water is circulated, the primary molten steel (M) injected into the cooling mold 110 It cools and converts into the slab S of the reaction solid state which the coagulation | solidification area | region (part B) and the unsolidification area | region (site A) coexist. On one side of the cooling mold 110 to prevent the sticking phenomenon (sticking) of the cooling mold 110 and the cast (S) sticking to each other, and in order to perform the drawing efficiently vibrating the cooling mold 110 in the vertical direction Mold vibration device (not shown) can be combined. In addition, a mold flux or oil may be applied to the inner wall surface of the cooling mold 110 in order to reduce the frictional force generated between the cooling mold 110 and the cast steel S.

The support 130 may vertically support the slab S drawn to the lower side of the cooling mold 110 and adjust the falling speed of the slab S, that is, the drawing speed. The support 130 is coupled to the lower surface of the surface plate 132 that supports the lower surface of the cast (S), the movement plate 134 and the movement plate 134 on which the surface plate 132 is seated, the movement plate 134. It includes a slab driving unit 136 for driving. Here, the slab driving unit 136 may be implemented in various ways, such as a gear (gear) method using a motor, a belt (belt) or pulley (pulley) method, a cylinder (cylinder) method, embodiments of the present invention In this case, the cylinder type using the hydraulic piston was used.

The surface plate 132 provided in the support 130 is a part or the whole of the body is inserted into the cooling mold 110 before the molten steel (M) is introduced, after the molten steel (M) is introduced into the cast steel (S) Descend gradually for drawing. When inserted into the cooling mold 110 of the surface plate 132, a sealing is formed between the outer circumferential surface of the surface plate 132 and the inner wall surface of the cooling mold 110 with an air gap. Therefore, the molten steel M introduced into the cooling mold 110 may be prevented from leaking into the fine spaced space between the surface plate 132 and the cooling mold 110. In the embodiments of the present invention, a plurality of grooves (not shown) are formed on the upper surface of the surface plate 132 to facilitate separation of the solidified slab S and the surface plate 132, and the upper surface of the surface plate 132. Chemicals of certain components may be applied to the.

The magnetic field applying unit 120 stirs and induction-heats the uncoagulated portion of the molten steel M and the cast steel S in the liquid phase to solidify the discontinuous layer A 'inside the cast steel S (FIG. 2A). Or voids. The magnetic field applying unit 120 according to the exemplary embodiment of the present invention includes a first guide 122 extending in a vertical direction with respect to the ground, and a first moving up and down along the extending length direction of the first guide 122. The magnetic field applying device 126 is coupled to the moving member 124 and one side of the first moving member 124 to insert the cooling mold 110 inward, and applies a magnetic field to the molten steel M and the cast steel S. And a first moving member driver (not shown) for supplying a driving force to the first moving member 124 by electric or hydraulic pressure and a magnetic field applying controller (not shown) for controlling the position of the first moving member 124. . Here, a position sensor (not shown) for detecting the height from the ground of the first moving member 124 is coupled to one side of the first moving member 124, the magnetic field applying control unit through the value detected by the position sensor 1 can accurately control the position of the moving member (124).

The magnetic field applying device 126 may be directly coupled to one side of the first moving member 124, and may use the magnetic field applying device support plate 128 on which the magnetic field applying device 126 may be seated for more stable coupling. have. At this time, the magnetic field applying device receiving plate 128 is also formed with a through hole having the same size and shape as the magnetic field applying device 126 so that the cooling mold 110 can be inserted therein. The magnetic field applying device 126 may be formed in various shapes such as a circular cross section, an oval shape or a rectangular shape in a horizontal cross section. In the embodiments of the present invention, the magnetic field applying device may apply the magnetic field evenly to the outer circumferential surface of the cast steel S. FIG. (126) was formed in a cylindrical shape.

When the magnetic field applying device 126 is located outside the cooling mold 110, the magnetic field is applied to the upper end of the liquid phase of the molten steel M to stir the molten steel M in the unsolidified state, and the eddy current By heating the molten steel (M) by the induction heating method using) can be prevented sudden solidification (hereinafter referred to as 'pre-solidification') caused by exposure to the atmosphere. In addition, when the cast (S) is drawn to the lower portion of the cooling mold 110, it is lowered to the same height as the top (top end of the cast) of the cast (S) to apply a magnetic field to the top of the cast (S). That is, induction heating is performed while generating physical agitation at the unsolidified portion (site A) inside the cast steel (S).

As described above, the magnetic field is applied to the molten steel (M) and the cast (S) through the magnetic field applying device 126 to minimize the generation of porosity (porosity) and pores of the molten steel (M) and the cast (S). In addition, the generation of the center segregation, the V-shaped segregation, and the inverted V-shaped segregation is reduced within the cast steel S, thereby improving the quality of the cast steel S. That is, by preventing the non-solidified portion (site A) of the top portion of the slab S from being pre-solidified, the shrinkage cavity may be minimized to improve the error rate of the slab S.

In an embodiment of the present invention, the magnetic field applying unit 120 includes one magnetic field applying device 126, but as in the other embodiment of the present invention shown in FIG. 4, the plurality of magnetic field applying devices 226 and 229 are provided. Using the vertical casting device 100 'can be implemented. (Two magnetic field applying devices are applied in FIG. 4) That is, in another embodiment according to the present invention, a plurality of magnetic field applying devices 226 and 229 are provided, so that one magnetic field applying device 229 is a cooling mold 110. It is fixed to be located at one side of the), and at least one of the other magnetic field applying device 226 can be driven up and down to maintain the same height from the top of the descending slab (S) and the ground.

In addition, the magnetic field applying device 226 that is vertically driven along the longitudinal direction of the slab (S) can be driven up and down in the entire region of the slab (S) can be applied to a portion other than the top of the slab (S).

In the embodiments of the present invention, when the effects of the stirring and induction heating of the magnetic field applying unit (120, 220) is insufficient to maximize the effect as shown in Figure 6 to the molten steel (M) (110) After the inflow of the) is completed, the heat insulating portion 190 covering the upper portion of the molten steel (M) inside the cooling mold 110 may be further coupled.

Here, the heat insulating portion 190 is inserted into the upper portion of the molten steel (M) and the upper and lower perforated steel can 192 covering the unsolidified molten steel portion (part A), and the heat insulating cover covering the open upper portion of the steel can 192 (heat insulation cover) 198. Meanwhile, the pyrogen material 194 and the heat insulating material 196 may be sequentially loaded into the steel can 192 before the upper portion of the steel can 192 is covered with the heat insulating cover 198. In the steel can 192 inserted into the molten steel M, the lower surface of the steel can 192 is automatically welded to the initial solidification layer of the molten steel M. The heat insulating unit 190 prevents heat loss of the top portion of the cast steel (S) and provides additional heat to the cast steel (S) through the heating material 192 loaded inside the steel can (192). ) Prevents precoagulation.

In the vertical casting apparatus (100, 100 ') according to the embodiments of the present invention, whether the stirring and induction heating by the magnetic field applying unit (120, 220) and the heating slab according to whether or not the coupling (190) Looking at the relationship between the depth of the shrinkage cavity of S) and the real rate of the cast (S) with reference to Figure 7 as follows. The size of the cast steel (S) used in the experimental example of Figure 7 is 700mm in the horizontal and vertical length in the horizontal cross section, respectively, the vertical length is drawn long enough. In addition, the amount of induction heating applied to the slab S by the magnetic field applying units 120 and 220 was 100 kW / m 2, and about 3 kg of the heating material 194 loaded on the heat generating unit 190 was used.

As a result of applying the experimental conditions as described above, the case of the molten steel (M) and the cast (S) and the stirring and heating (induction heating) was about 30% higher than the case without this, the yield of the cast steel (%) improved, In the case where the thermal insulation unit 190 is applied together with the magnetic field applying unit 120, 220, the yield rate (%) of the cast steel is improved by about 4% compared to the case where the magnetic field applying unit 120, 220 is applied alone. That is, it could be confirmed that the effects of the stirring and heating by the magnetic field applying unit 120 are greater than the effects by the exothermic heat keeping unit 190. In addition, it was confirmed that the application of the magnetic field applying unit (120, 220) and the heat insulating portion 190 in the production of large ingots of excellent quality in the casting method.

The solidification unit 170 is a means for secondarily cooling the slab S that is first cooled in the cooling mold 110, and the cooling mold 110 does not interfere with the vertical driving of the magnetic field applying units 120 and 220 and the support unit 130. It is installed directly below 110. The solidification unit 170 physically hinders the expansion of the slab S while passing the slab S downward, and a plurality of foot rolls 172 for guiding the slab S in a direction perpendicular to the ground. And a plurality of cooling nozzles 174 for secondary cooling of the cast steel S by spraying or spraying cooling water on the cast steel S passing through the foot roll 172.

Directly below the solidification unit 170 as described above is driven up and down along the moving cast (S) to the leading end of the cast (S), where the leading end of the cast (S) is the lowest end of the cast (S) in contact with the support 130 Cooling unit 180 for cooling) is provided.

The cooling unit 180 casts a recuperation prevention spraying device 182 (see FIG. 5) and a recuperation preventing spraying device 182 including a plurality of cooling nozzles 184 for injecting cooling water to the outer circumferential surface of the tip portion of the cast steel S. (S) It includes a cooling drive unit for driving up and down so as to be the same height from the front end portion and the ground.

Here, the cooling drive unit according to the embodiments of the present invention is moved up and down along the extended length direction of the second guide 187 and the second guide 187 extending in the vertical direction with respect to the ground spray prevention device A second moving member 186 for vertically driving 182, a cooling water supply tank 186 coupled to one side of the second moving member 186 to supply cooling water to the plurality of cooling nozzles 184, and Cooling control unit for controlling the position of the second moving member driving unit (not shown) and the second moving member 186 and the amount of cooling water injected to the plurality of cooling nozzles 184 to supply the driving force to the second moving member 186 (not shown) City).

In the embodiments of the present invention, the side wall of the anti-reheat spray device 182 is opened so that the magnetic field application devices 126 and 226 are located outside the anti-reheat spray device 182 so as not to interfere with the application of the magnetic field. Here, if the cooling unit 180 and the magnetic field applying unit 120 which is driven up and down along the cast (S) does not interfere, it is a matter of course that the anti-reheat spray device 182 may be formed in various shapes and structures. In addition, in the embodiments of the present invention, although the cooling water supply tank 186 is coupled to one side of the second moving member 186, a cooling water supply tank is separately formed on one side of the vertical casting apparatuses 100 and 100 ', A plurality of cooling water supply pipes may be connected to the plurality of cooling nozzles 184 to spray the cooling water.

On the other hand, at least one position sensor (not shown) and a temperature sensor (not shown) are attached to one side of the second moving member 186 or one side of the anti-reheat spray device 182, respectively. When the tip of the cast (S) passes through the solidification unit 170, the position sensor may be used to detect the height from the ground of the tip of the cast (S). In addition, when the tip portion of the cast (S) passes through the solidification portion 170, it is possible to measure the temperature of the tip portion of the cast (S) using a temperature sensor.

As described above, by having a cooling unit 180 that can continuously cool the front end of the cast (S) in spite of the movement of the cast (S) can prevent re-dissolution by reheating generated inside the cast (S). have. Referring to FIGS. 8 and 9, FIG. 8A is a graph measuring a change in temperature according to a distance of the cast steel S when the cooling unit 180 is not applied. 8 (b) is a graph measuring the temperature change according to the moving distance of the mold (S) when the cooling unit 180 is applied. (Where t1 is the temperature at the time of the mold passing, t2 is the temperature at the solidification part, and t3 is the temperature when passing through the solidification part.)

Referring to parts t3 shown in FIGS. 8 (a) and 8 (b), when the cooling unit 180 is not applied, the temperature of the tip portion of the slab (S) is increased again by reheating generated inside the slab (S). It can be confirmed that (see Fig. 9 (a)), when the cooling unit 180 is applied to suppress the reheating generated in the inside of the cast (S) to gradually cool the temperature of the tip of the cast (S) does not rise again It can be confirmed (see Fig. 9 (b)).

Therefore, by cooling the tip of the cast (S) during the solidification of the cast (S) using the cooling unit 180, it is possible to prevent the temperature of the cast (S) uneven along the longitudinal direction. That is, the quality of the slab S can be improved by preventing defects, such as a solidification discontinuous layer A 'and a space | gap, from occurring inside the slab S.

As described above, when the cooling in the cooling unit 180 elapses for a predetermined time and the solidification of the slab S is completed, the separating unit 140 located on one side of the slab S operates. Here, one side of the cast (S) means any one of the left or right of the cast (S).

Separation unit 140 is separated from the surface plate 132 by pushing the slag (S) is solidified completed by applying a force from one side. To this end, the separating unit 140 is spaced at regular intervals vertically with respect to the ground, a plurality of hydraulic pushing device 142 is used to reciprocate in the horizontal direction with respect to the ground. As in the embodiments of the present invention, by cutting the cast (S) from the surface plate 132 automatically, the cutting using the torch or the like is not made when separating the surface plate 132 and the cast (S). Therefore, the error rate of the cast steel (S) can be prevented from being lowered, and the productivity can be improved by shortening the recovery time of the surface plate 132, the preparation time for reuse, and the like.

The rotary feeder 150 includes a rotary roller table 152 that receives the slab S 'separated from the surface plate 132, a tilting device 154 that rotates the rotary roller table 152 in a horizontal direction, and The rotary roller table 152 and the transfer roller table 156 extending in the horizontal direction. In the initial state, the rotatable roller table 152 waits with the portion supporting the cast steel S vertical, and is passed when the cast steel S is pushed out by the plurality of hydraulic pushing devices 142, At the same time, the tilt of the rotary roller table 152 is adjusted by the tilting device 154 so that the slab S 'is placed horizontally with respect to the ground.

The feed roller table 156 installed in the extended length direction of the horizontally rotated rotary roller table 152 transfers the cast steel S 'to the cutting unit 160 or the post process horizontally.

The horizontally transported cast steel S 'passes through a cut portion 160 provided on an extension line of the transfer roller table 156 so as to be cut to a size required in a later process. When the heating insulation unit 190 is coupled to one end of the slab S ', the heating insulation unit 190 may be removed from the slab S by using the cutting unit 160.

Hereinafter, a casting method using the vertical casting apparatus according to the present invention will be described with reference to the accompanying drawings.

10 is a view showing an operating state of the vertical casting apparatus according to the present invention, Figure 11 is a flow chart showing a vertical casting method according to an embodiment of the present invention.

10 and 11, the vertical casting method according to an embodiment of the present invention is a step of inserting the surface of the support to the lower portion of the cooling mold as a step before the start of casting (Fig. 10 (a); 10 (b)), the step of first cooling the molten steel into the cooling mold (S120; Fig. 10 (b)), and the step of stirring and induction heating the molten steel using a magnetic field applying unit outside the cooling mold (S130 10 (b)), drawing the slab to the lower side of the cooling mold while lowering the support plate (S140; FIG. 10 (c)), and passing the slab through a solidification portion provided directly below the cooling mold. The second step of cooling (S150; Fig. 10 (c)), the step of moving the magnetic field applying unit and stirring and induction heating the slab passed through the coagulation unit (S160; Fig. 10 (d)) and the slab directly under the solidification part And driving the cooling unit to cool the cast slab three times (S170; FIG. 10 (d)).

In addition, in the vertical casting method according to an embodiment of the present invention after the step of cooling the cast using a cooling unit (S170), when the solidification of the cast after a certain time has elapsed is pushed from one side of the cast to separate from the support portion In addition, the method further includes a step of horizontally rotating the separated slab for feeding (S180) and cutting the transferred slab to a predetermined length using a cutting torch or the like (S190).

When a certain amount of molten steel flowing from the tundish is introduced into the cooling mold, the upper portion of the molten steel may be covered with a heat generating insulating part before stirring and induction heating of the molten steel by using a magnetic field applying part by the operator's choice (S135). That is, the quality of the cast steel can be improved by preventing the linear solidification of the upper portion of the molten steel is exposed to the atmosphere and rapidly cooled.

If the upper portion of the molten steel is combined with the heat insulating portion, in step S190 of cutting the slab to a certain length, the heat insulating portion may be removed from the slab. (Here, since the shape and size of the horizontal cross section of the heat generating thermal insulation portion are formed smaller than the shape and size of the horizontal cross section of the mold, the heating insulation portion does not protrude to the outside of the cast steel. .)

In addition, even after the molten steel is first cooled in the cooling mold and secondly cooled while passing through the solidification part, there is a liquid non-solidified portion inside the cast steel due to the large size of the cast steel. The slabs are redissolved by the reheating caused by the uncoagulated portion of the liquid phase, and the distal ends of the slabs, which are already solidified, cause temperature imbalance in the slabs. Thus, in one embodiment of the present invention, to prevent the temperature imbalance of the cast steel by using a cooling unit, the front end portion of the cast is cooled to maintain a constant temperature without reheating by reheating.

Here, the step of cooling the cast using the cooling unit includes the steps of detecting the position of the tip of the slab when the tip of the slab in contact with the support passes through the solidification, measuring the temperature of the tip of the slab when passing through the solidification; Driving the cooling unit up and down at the same speed as the descending speed of the cast steel so that the tip and the cooling unit are kept at the same height from the ground, and controlling the amount of cooling water injected toward the tip of the cast steel, that is, the temperature at which the temperature of the cast steel tip is measured, that is, the solidification part. Cooling so as not to rise above the temperature at the time of passage.

As described above, the vertical casting apparatus and the casting method using the same according to the embodiments of the present invention can improve the quality of the cast by preventing the surface damage of the cooling mold using a fixed cooling mold.

In addition, the top portion of the molten steel flowing into the cooling mold and the cooling mold can be continuously cooled along the longitudinal direction by stirring and induction heating using a magnetic field applying portion. That is, the quality of the cast can be improved by preventing the solidification discontinuity layer or voids from occurring in the cast.

In addition, it is possible to prevent the temperature imbalance due to reheating generated in the interior of the slab by having a cooling unit for continuously cooling the front end portion of the slab during the drawing and solidification process. That is, it is possible to prevent defects such as solidification discontinuity layers and voids inside the cast, thereby reducing the defective rate of the cast.

In addition, it is possible to easily separate the cast slab after solidification from the surface plate to facilitate the operation process, it is possible to improve the error rate of the cast.

Therefore, the vertical casting apparatus and the casting method using the same according to the embodiments of the present invention can improve the productivity of the process of producing a large ingot (cast).

As mentioned above, although this invention was demonstrated with reference to the above-mentioned embodiment and an accompanying drawing, this invention is not limited to this, It is limited by the following claims. Therefore, it will be apparent to those skilled in the art that the present invention may be variously modified and modified without departing from the technical spirit of the following claims.

1 is a view showing a vertical casting apparatus according to a conventional embodiment.

FIG. 2 is a view schematically showing the internal state of a slab in which a solidification discontinuous layer and a solidification continuous layer are formed. FIG.

3 is a view showing the configuration of a vertical casting apparatus according to an embodiment of the present invention.

4 is a view showing the configuration of a vertical casting apparatus according to another embodiment of the present invention.

5 is a view showing a cooling unit according to an embodiment of the present invention.

Figure 6 is a view showing a state in which the heating insulation coupled to the vertical casting apparatus according to the embodiments of the present invention.

7 to 9 are graphs and state diagrams showing an experimental example of a vertical casting apparatus according to embodiments of the present invention.

10 is a view showing an operating state of the vertical casting apparatus according to the present invention.

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

Description of the Related Art [0002]

100, 100 ': vertical casting apparatus 110: cooling mold

120: magnetic field applying portion 130: support portion

140: separation unit 150: rotation transfer unit

160: cutting unit 170: solidification unit

180: cooling unit 190: heat insulation

Claims (22)

A cooling mold into which molten steel flows; A support part for supporting a cast piece drawn to the lower side of the cooling mold; A solidification part provided under the cooling mold to cool the cast steel; A magnetic field applying unit which is driven up and down along the cast steel from the outside of the cooling mold and stirs and induces heating of the molten steel and the cast steel; And A cooling unit which is driven up and down along the cast steel directly below the solidification part to cool the cast steel; Vertical casting device comprising a. A cooling mold into which molten steel flows; A support part for supporting a cast piece drawn to the lower side of the cooling mold; A solidification part provided under the cooling mold to cool the cast steel; A cooling unit which is driven up and down along the cast piece directly under the solidification part to cool the cast piece; A separating part provided at one side of the cast piece to separate the support part by pushing the cast piece; And A rotation transfer part provided on the other side of the cast piece facing the separating part to rotate and horizontally feed the cast piece; Vertical casting device comprising a. The method according to claim 1, A vertical type further comprising a separating part provided on one side of the slab and pushing the slab to separate the support part, and a rotating transfer part provided on the other side of the slab facing the separating part to rotate and horizontally transport the slab. Casting device. The method according to any one of claims 1 to 3, The cooling unit, The vertical casting device for cooling the leading end of the slab in contact with the support by driving up and down along the drawing direction of the cast. The method according to any one of claims 1 to 3, Vertical casting apparatus further comprises a heat insulation to cover the upper portion of the molten steel introduced into the cooling mold. The method according to claim 5, The heat insulation unit, And a vertically penetrated steel can inserted into an upper portion of the molten steel and loaded with a heat generating material and an insulating material inwardly, and a heat insulating cover covering an open upper portion of the steel can. The method according to any one of claims 1 to 3, The cooling mold, Cooling water pipe circulating the cooling water is provided on the inside, vertical casting apparatus coupled to the mold vibration device for vibrating the cooling mold up and down to one side. The method according to any one of claims 1 to 3, The support portion A surface plate supporting the lower end of the cast steel; A moving plate on which the surface plate is seated; And A slab driving part coupled to a lower portion of the movable plate to drive the movable plate up and down; Vertical casting device comprising a. The method according to claim 1 or 3, The magnetic field applying unit, A first guide extending in a direction perpendicular to the ground; A first moving member moved up and down along an extended length direction of the first guide; A magnetic field applying device coupled to one side of the first moving member to insert the cooling mold inward and to apply a magnetic field to the molten steel and the cast steel; A first moving member driving unit supplying a driving force to the first moving member; And A magnetic field applying control unit controlling a position of the first moving member; Vertical casting device comprising a. The method according to claim 9, The magnetic field applying device is provided with a plurality of magnetic field applying devices, and the magnetic field applying device is fixed to one side of the cooling mold, and at least one of the other magnetic field applying devices is driven up and down directly under the solidification part as the slab descends. Vertical casting device. The method according to claim 9, One side of the first moving member is a vertical casting device is attached to the position sensor for detecting the position of the cast. The method according to any one of claims 1 to 3, The coagulation unit, A plurality of foot rolls for preventing expansion of the cast steel drawn to the lower side of the cooling mold and guiding a drawing direction of the cast steel; A plurality of cooling nozzles for injecting cooling water into the cast steel; Vertical casting device comprising a. The method according to claim 4, The cooling unit, A recuperation prevention spraying device having a plurality of cooling nozzles for spraying cooling water on an outer circumferential surface of the tip portion of the cast steel; A cooling drive unit configured to vertically drive the anti-reheat spray device so as to have the same height from the front end of the cast steel; Vertical casting device comprising a. 14. The method of claim 13, The cooling drive unit, A second guide extending in a direction perpendicular to the ground; A second moving member moved up and down along the extended length direction of the second guide to vertically drive the anti-reheating spray device; A cooling water supply tank coupled to one side of the second moving member to supply cooling water to the plurality of cooling nozzles; A second moving member driver for supplying a driving force to the second moving member; And A cooling control unit controlling a position of the second moving member and a cooling water injection amount; Vertical casting device comprising a. The method according to claim 14, At least one position sensor and a temperature sensor are attached to one side of the second moving member or one side of the recuperation preventing spray device, respectively. The method according to claim 2 or 3, The separation unit, A vertical casting apparatus comprising a plurality of hydraulic pushing devices aligned in a direction perpendicular to the ground and driven in a horizontal direction with respect to the ground. The method according to claim 2 or 3, The rotation transfer unit, A rotatable roller table receiving the slab separated from the support; A tilting device for rotating the rotatable roller table; And A conveying roller table extending in a horizontal direction with the rotated rotatable roller table; Vertical casting device comprising a. Inserting the surface plate of the support into the lower portion of the cooling mold; Introducing molten steel into the cooling mold; Stirring and induction heating the molten steel using a magnetic field applying unit outside the cooling mold; Drawing the slab to the lower side of the cooling mold while lowering the surface plate; Passing the slab through a solidification unit provided directly below the cooling mold; Stirring and induction heating the slab passing through the solidification unit by moving the magnetic field applying unit; And Cooling the cast piece by driving a cooling part up and down along the cast piece directly under the solidification part; Vertical casting method comprising a. Inserting the surface plate of the support into the lower portion of the cooling mold; Introducing molten steel into the cooling mold; Drawing the slab to the lower side of the cooling mold while lowering the surface plate; Passing the slab through a solidification unit provided directly below the cooling mold; Cooling the cast piece by driving a cooling part up and down along the cast piece directly under the solidification part; Pushing the solidified cast piece from one side to separate from the support part; Horizontally rotating and separating the separated cast steel; And Cutting the transferred cast piece to a constant length; Vertical casting method comprising a. 19. The method of claim 18, After the step of cooling the cast using the cooling unit, When the solidification of the slab is completed, pushing the slab from one side to separate from the support; Horizontally rotating and separating the separated cast steel; And Cutting the transferred cast piece to a constant length; Vertical casting method further comprising a. The method according to any one of claims 18 to 20, Cooling the cast using the cooling unit, Sensing the position of the slab tip when the slab tip in contact with the support passes through the solidification part; Measuring the temperature of the tip of the slab as it passes through the solidification section; Driving the cooling unit up and down at the same speed as the descending speed of the slab so that the slab front end and the cooling unit remain at the same height from the ground; Adjusting the amount of cooling water sprayed toward the front end of the slab to cool the temperature so that the temperature of the front end of the slab does not rise above the measured temperature; Vertical casting method comprising a. The method according to any one of claims 18 to 21, When the inflow of the molten steel to the cooling mold is completed, vertical casting method further comprising the step of coupling the heat insulation to cover the upper portion of the molten steel to the inside of the cooling mold.

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