KR102179558B1 - Mold, apparatus and method for casting - Google Patents

Abstract

The present invention relates to a casting mold, a casting apparatus, and a casting method, comprising: a first body providing a first space for cooling a melt; And a second body connected to the first body to provide a second space for cooling the molten material to form a casting, and to communicate the first space and the second space; wherein, the second body By forming at least a material having a higher thermal conductivity than the first body, casting can be stably performed by controlling the cooling rate of the melt in the mold during the casting process, and the quality of the casting can be improved.

Description

Casting mold, casting apparatus, and casting method {Mold, apparatus and method for casting}

The present invention relates to a casting mold, a casting apparatus, and a casting method, and more particularly, to a casting mold, a casting apparatus, and a casting method capable of improving the quality of a casting by stably performing casting.

The horizontal casting method is known as one of the methods of casting an alloy into a thin bar or plate. The horizontal casting method is a technology in which a mold is placed in a container in which the melt is accommodated in a horizontal direction, and the cast product cast from the mold is drawn in the horizontal direction. Such a horizontal casting method has a simpler manufacturing process and a low process cost compared to the vertical casting method, so it is widely used in alloy manufacturing.

However, in the case of the horizontal casting method, since the cast product cast in the mold is forcibly drawn using a drawing roll, it is good to reduce the frictional force generated between the cast product and the mold. That is, since the alloy contains various components, a solid-liquid coexistence region in which a solid phase and a liquid phase coexist may be formed in a state in which the casting is not completely solidified. At this time, if the solidification of the melt is delayed in the mold and the solid-liquid coexistence region is prolonged, inverse segregation may occur in which a component with a relatively low melting point of the melt escapes to the surface of the cast and solidifies at the surface of the cast. As a result, the surface of the casting is rough, causing friction between the casting and the mold. In addition, in the horizontal casting method, a mold is formed using graphite for lubrication of the casting. When the solidification of the melt is delayed, a certain component in the melt reacts with graphite to form a reactant such as carbide in the mold.

In this way, due to the reverse segregation formed on the surface of the casting and the reactants formed in the mold, frictional force is generated between the casting and the mold, resulting in a defect on the surface of the casting, and the mold is easily worn. In particular, there is a problem in that the casting is not properly drawn out due to friction between the casting and the mold and is cut in the mold, so that casting must be stopped.

KR 0228574 B KR 1999-0046618 A

The present invention provides a casting mold, a casting apparatus, and a casting method capable of improving the quality of the casting by controlling the cooling rate of the melt.

The present invention provides a casting mold, a casting apparatus, and a casting method capable of improving the quality of a casting by stably performing casting.

A casting mold according to an embodiment of the present invention is a casting mold, comprising: a first body providing a first space for cooling a melt; And a second body connected to the first body to provide a second space for cooling the molten material to form a casting, and to communicate the first space and the second space; wherein, the second body It may be formed of a material having a higher thermal conductivity than at least the first body.

The second body may include a material having a thermal conductivity of 5 to 20 times greater than that of the first body.

The first body may include at least one of boron nitride, zirconium carbide, and graphite, and the second body may include at least one of copper and silicon carbide.

A third body connected to the second body to provide a third space for forming a movement path of the casting and to communicate the third space and the second space; And a cooling jacket provided on the outside of the second body and the third body.

The third body may include at least one of boron nitride, zirconium carbide, and graphite.

The second body may be formed to have a length of 2 to 3 times the length of the first body, and the third body may be formed to have a length of 5 to 7 times that of the first body.

The cooling jacket includes: a first cooling jacket having a first flow path formed therein to form a moving path of the cooling medium, and provided outside the second body; And a second cooling jacket having a second passage forming a moving path of the cooling medium therein, and provided on the outside of the third body, wherein the diameter of the first passage is at least the diameter of the second passage It can be formed larger.

An insulating material may be provided between the first cooling jacket and the second cooling jacket.

A casting apparatus according to an embodiment of the present invention is a casting apparatus for casting a cast product, comprising: a container providing a space to accommodate a molten product; And a mold connected to the container to solidify the melt discharged from the container to cast a cast product, wherein the mold may include different types of materials having different thermal conductivity along the casting direction.

The mold is connected to the container so as to extend in a horizontal direction, the first body connected to the container; And a second body formed of a material having a higher thermal conductivity than the first body and connected to the first body.

The first body may be formed of a material having a thermal conductivity of 20 to 40 W/m·K, and the second body may be formed of a material having a thermal conductivity of 100 to 400 W/m·K.

A third body connected to the second body may be further included, and the third body may be formed of a material having a lower thermal conductivity than the second body.

The mold includes a cooling medium supply unit for supplying a cooling medium to the cooling jacket, including a cooling jacket provided outside the second body and the third body; And a controller capable of controlling an operation of the cooling medium supply unit to adjust the supply speed of the cooling medium.

The cooling jacket may include a first cooling jacket provided on the outside of the second body; And a second cooling jacket provided outside the third body, wherein the control unit includes the cooling medium supply unit to adjust a supply speed of the cooling medium supplied to each of the first cooling jacket and the second cooling jacket. You can control the operation.

An insulating material may be provided between the first cooling jacket and the second cooling jacket.

A casting method according to an embodiment of the present invention is a method of casting a casting, comprising: providing a melt in a container; And discharging the melt into a mold connected to the container. And a process of casting a cast by cooling the melt discharged to the mold, wherein the process of casting the cast may include a process of changing the cooling rate of the melt at least in part along the casting direction.

The casting process may include cooling the melt at a first cooling rate; It may include a process of cooling the cooled melt at a second cooling rate higher than the first cooling rate to cast a solidified cast.

The casting process may include a process of transferring the casting while cooling the casting at a third cooling rate lower than the second cooling rate in the mold.

In the casting process, the first cooling rate, the second cooling rate, and the third cooling rate may be adjusted using thermal conductivity of a material constituting the mold.

The second cooling rate and the third cooling rate may be adjusted using at least one of a supply flow rate, a supply rate, and a type of cooling medium of the cooling medium supplied to the mold.

The process of preparing the molten material includes a process of preparing a copper alloy, and the process of casting may include a process of drawing a bar or plate material having a thickness of 5 to 20 mm into the casting in a horizontal direction and casting. have.

According to an embodiment of the present invention, casting can be stably performed by controlling the cooling rate of the melt in the mold during the casting process, and the quality of the casting can be improved. In other words, the cooling rate of the melt in the mold. That is, by controlling the solidification rate, the occurrence of reverse segregation in the casting can be suppressed. In addition, in the process of solidifying the melt, it is possible to inhibit the formation of a reactant by reacting a specific component of the melt with a material constituting the mold. Therefore, it is possible to suppress or prevent the occurrence of defects on the surface of the casting or wear of the mold by reverse segregation or reactants. In addition, it is possible to enable stable casting by smoothing the drawing of the casting.

In addition, since the mold can be partially replaced, the maintenance cost of the mold can be reduced.

1 is a view schematically showing a casting apparatus according to an embodiment of the present invention.
2 is a cross-sectional view of a mold applied to the casting apparatus according to an embodiment of the present invention.
3 is a cross-sectional view showing a modified example of a mold.
4 is a view showing the temperature change of the casting in the casting direction according to the material of the mold.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and the scope of the invention to those of ordinary skill in the art It is provided to inform you. In the description, the same reference numerals are assigned to the same components, and the drawings may be partially exaggerated in size in order to accurately describe the embodiments of the present invention, and the same numerals refer to the same elements in the drawings.

The casting apparatus according to an embodiment of the present invention is an apparatus for casting a casting in a horizontal direction, and may cast a bar or plate using phosphor bronze or a copper alloy containing titanium, chromium, zirconium, aluminum, or the like. At this time, the bar material may be cast to have a diameter of about 5 to 20 mm, in the case of a plate material may be cast to have a thickness of about 5 to 20 mm and a width of about 10 to 100 mm.

1 is a view schematically showing a casting apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a mold applied to the casting apparatus according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a modified example of the mold .

Referring to Figure 1, the casting apparatus according to an embodiment of the present invention, to cast a casting (S) by solidifying the melt discharged from the container 100 and the container 100 to provide a space to accommodate the melt It may include a mold 200 connected to the container 100. In this case, the mold 200 may include different types of materials having different thermal conductivity along the casting direction. In addition, the casting apparatus according to the embodiment of the present invention is provided in the front of the mold 200 in the casting direction and between the drawing unit 400 including a pair of rolls, and the mold 200 and the drawing unit 400 In the casting (S) may further include a cooling unit 300 for spraying the cooling water. In addition, the casting apparatus may include a cooling medium supply unit (not shown) for supplying the cooling medium to the mold 200 and a control unit (not shown) for controlling the operation of the cooling medium supply unit.

The container 100 may provide a space for accommodating a melt therein. In addition, the container 100 may be provided with an outlet 110 capable of discharging the melt to the mold 200. In this case, the outlet 110 may be formed on the side of the container 100. Such a container 100 may be formed of a refractory material to suppress a decrease in the temperature of the melt or to maintain a constant temperature of the melt. In addition, an insulation material (not shown) or a heating device (not shown) of the melt may be provided outside the container 100.

The mold 200 may be connected to the container 100 to form a cast by solidifying the melt discharged from the container 100, and may be inserted into the discharge port 110 and connected to the container 100. In this case, the mold 200 may be connected to the container 100 in a horizontal direction so as to form a cast in a horizontal direction.

The mold 200 includes a body 210 that provides a space for cooling the melt to form a cast, and a cooling jacket 220 provided on the outside of the body 210 to surround at least a part of the body 210 can do. At this time, at least a portion of the mold 200 may be inserted into the outlet 110 and supported by the container 100.

The body 210 may be formed by being divided into a plurality of parts so as to control the cooling rate of the melt, for example, the solidification rate along the casting direction. The body 210 may include a first body 210a providing a first space for cooling the melt, and a second body 210b providing a second space for cooling the melt to form a cast. . In addition, the body 210 may include a third body 210c that provides a third space for transporting the cast product cast in the second body 210b to the outside of the mold 200. At this time, the first body 210a, the second body 210b, and the third body 210c may be formed of different materials having different thermal conductivity. In addition, the first space, the second space, and the third space may be formed in various shapes such as a circle, an ellipse, and a polygon according to the shape of the casting to be cast.

The first body 210a may be inserted into the outlet 110 to allow the molten material contained in the container 100 to flow into the mold 200 and cool the molten material, for example, initial cooling. In this case, a part of the first body 210a inserted into the outlet 110 may directly contact the melt inside the container 100. Therefore, when the first body 210a is formed using a material having very high thermal conductivity, the melt in contact with the first body 210a may be rapidly cooled and solidified. In this case, the melt is solidified and adheres around the first body 210a, which may cause a problem in that the melt does not flow smoothly into the mold 200. In addition, there is a problem in that the growth of dendrite is promoted by rapid cooling of the melt, thereby deteriorating the quality of the casting. In addition, when a plate material is formed as a cast, there is a problem in that it is difficult to uniformly solidify the melt along the width direction of the mold.

Therefore, the first body 210a may be formed of a material having a low thermal conductivity, for example, about 20 to 40 W/m·K, so that the melt can be gradually cooled. Materials having such thermal conductivity include graphite, zirconium carbide (ZrC), boron nitride (BN), and the like. If the thermal conductivity of the first body 210a is too low, cooling of the melt is hardly performed, so that the time for forming the solidified material, that is, the cast, may be delayed. On the other hand, if the thermal conductivity of the first body 210a is too high, the melt in the container 100 forms a solidified material around the first body 210a, so that the melt is not properly injected into the mold 200, or dendrite. ) Growth is promoted and the quality of the casting is deteriorated.

The second body 210b may serve to form a cast by cooling the melt. The second body 210b may be formed to be exposed to the outside of the container 100 together with the third body 210c. The second body 210b can form a casting by rapidly cooling the melt that has started to cool and solidify in the first body 210a to complete solidification.

When casting a casting using an alloy, the molten material may be solidified from the surface in contact with the mold to the inside to form a casting. At this time, since the alloy contains various components, a solid-liquid coexistence region in which a solid phase and a liquid phase coexist may be formed inside the casting when the casting is not completely solidified. However, when the solid-liquid coexistence region expands or increases, a component having a relatively low melting point in the melt may escape to the surface of the casting and cause inverse segregation to solidify on the surface of the casting. As a result, the surface of the casting may be rough and friction may occur between the casting and the body 210, thereby causing the body 210 to wear.

Therefore, in order to suppress or prevent reverse segregation from occurring, it is necessary to rapidly cool the melt to reduce the solid-liquid coexistence area. Accordingly, the second body 210b may be formed of a material having high thermal conductivity so as to increase the cooling rate of the melt. At this time, the second body 210b may be formed using a material having thermal conductivity capable of rapidly cooling the melt to complete solidification. Such thermal conductivity may be about 100 to 400 W/m·K, and materials having such thermal conductivity include silicon carbide (SiC) and copper (Cu).

On the other hand, when the second body 210b is formed using silicon carbide, copper, or the like, a phenomenon in which a specific component in the melt reacts with the material constituting the body 210 to form a reactant can be suppressed. In general, a mold applied during horizontal casting has a body formed of graphite. Accordingly, during the casting process, components such as titanium, zirconium, and chromium in the melt react with graphite to form carbides. However, when the second body 210b is formed of silicon carbide or copper having high thermal conductivity, such a reaction may be suppressed while the melt is rapidly solidified. In particular, since the second body 210b is not formed of graphite formed of a carbon component, such a reaction can be fundamentally prevented.

In addition, the length L2 of the second body 210b may be formed to be about 2 to 3 times longer than the length L1 of the first body 210a. In this case, the length L1 of the first body 210a may be formed to have a thickness thinner than the wall thickness or the wall thickness of the container 100. If the length L2 of the second body 210b is too short, the melt cannot be completely solidified even if the thermal conductivity of the second body 210b is high. On the other hand. If the length (L2) of the second body (210b) is too long, the melt is completely solidified, and the resulting cast moves along the second body (210b) and frictional force is generated to damage or wear the second body (210b). There is.

The third body 210c may be used as a path for transporting the cast product that has been solidified in the second body 210b to the outside. The material forming the third body 210c has a thermal conductivity as large as the material of the second body 210b because the casting product, which has completely solidified the melt in the second body 210b, is transferred to the third body 210c. There is no need. Therefore, the third body 210c may be formed of a material having a smaller thermal conductivity than the second body 210b. Accordingly, the third body 210c may be formed of the same graphite, boron nitride, zirconium carbide, or the like as the material constituting the first body 210a. However, since the horizontal casting is made by forcibly drawing the casting from the drawing part 400 disposed in front of the mold 200 in the casting direction, the casting completed solidification in the second body 210b is the third body ( In order to be smoothly transferred from 210c), the third body 210c is preferably formed of a material capable of imparting a lubricating action. Accordingly, the third body 210c is preferably formed of graphite having lubricating ability to reduce frictional force with the casting.

In addition, the length L3 of the third body 210c may be formed to be about 5 to 7 times longer than the length L1 of the first body 210a. If the length L3 of the third body 210c is too short, the cast product may be discharged to the outside without being sufficiently cooled in the mold 200. Accordingly, even if the cooling unit 300 sprays cooling water onto the casting, the casting is not sufficiently cooled, so that the heat of the casting may adversely affect the drawing unit 400. On the other hand. If the length L3 of the third body 210c is too long, the size of the entire casting apparatus increases, which is not good for space utilization.

In this way, the body 210 constituting the mold 200 is formed by dividing along the casting direction, and each body 210 is formed using materials having different thermal conductivity, for example, different types of materials, thereby effectively casting a casting. I can.

Meanwhile, the mold 200 may include a part of the body 210, that is, a cooling jacket 220 provided outside the second body 210b and the third body 210c. In this case, the first body 210a may be inserted into the discharge port 110 through the refractory 201 on the outside.

The cooling jacket 220 is provided so as to be in close contact with the body 210, and may serve to cool the body 210 in order to cool the melt or casting. A flow path 224 used as a moving path of a cooling medium for cooling the body 210 may be formed inside the cooling jacket 220. At this time, the cooling jacket 220 is formed to simultaneously surround the outside of the second body 210b and the third body 210c, and the flow path 224 may be continuously formed inside the cooling jacket 220.

3 is a view showing a modified example of the cooling jacket 220.

First, referring to (a) of FIG. 3, the cooling jacket 220 includes a first cooling jacket 222a provided on the outside of the second body 210b, and a first cooling jacket 222a provided on the outside of the third body 210c. It may be divided into two cooling jackets 222b. In this case, a first flow path 224a used as a movement path of the cooling medium is formed inside the first cooling jacket 222a, and a first flow path 224a used as a movement path of the cooling medium is formed inside the second cooling jacket 222b. Two passages (224b) may be formed. In addition, the first flow passage 224a and the second flow passage 224b may be separately formed so as to independently move the cooling medium. In this case, the first flow path 224a and the second flow path 224b may have the same diameter, or a diameter of the first flow path 224a may be larger than the diameter of the second flow path 224b.

When the cooling jacket 220 is divided and formed in this way, as shown in FIG. 2, the second body (210b) and the third body (210c) are simultaneously cooled with one cooling jacket (220). 210b) can be cooled more effectively. That is, in the case of forming to surround the second body 210b and the third body 210c with one cooling jacket 220, the cooling medium must cool both the second body 210b and the third body 210c. Therefore, the cooling efficiency of the second body 210b may be lowered. However, if the second body 210b and the third body 210c are independently cooled with different cooling jackets, the second body 210b and the third body 210c, in particular, the second body 210b requiring rapid cooling Can be cooled more effectively.

3B is another modified example of the cooling jacket, and an insulating material 230 may be additionally provided between the first cooling jacket 222a and the second cooling jacket 222b. In this case, the heat insulating material 230 may be formed in a portion where the third body 210c is formed at the boundary between the second body 210b and the third body 210c. This is to prevent the cooling efficiency of the second body 210b from being lowered by the heat insulating material 230. The heat insulating material 230 further enhances the cooling efficiency of the second body 210b by the first cooling jacket 222a by inhibiting or preventing heat from the second cooling jacket 222b from being transferred to the first cooling jacket 222a. Can be improved.

The cooling medium supply unit may supply a cooling medium to the cooling jacket 220. The cooling medium supply unit may include a storage device (not shown) for storing the cooling medium, and a flow controller (not shown) for adjusting the flow rate of the cooling medium.

One or more reservoirs may be provided. In this case, when a plurality of reservoirs are provided, each reservoir may store a different type of cooling medium.

The flow regulator is connected to the reservoir to control the flow rate of the cooling medium discharged from the reservoir. In this case, when a plurality of reservoirs are provided, the flow rate controller may be provided for each reservoir.

Further, the control unit may control the operation of the cooling medium supply unit. In this case, the controller may adjust the flow rate of the cooling medium supplied to the cooling jacket 220 by adjusting the flow rate controller of the cooling medium. In addition, when a plurality of reservoirs are provided, the flow rate of the cooling medium discharged from the reservoir may be independently controlled by controlling a flow controller provided for each reservoir.

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

A casting method according to an embodiment of the present invention includes a process of preparing a molten material in a container, a process of discharging the molten material with a mold connected to the container, and a process of casting a casting by cooling the molten material discharged from the mold. The process of casting may include changing the cooling rate of the melt in at least a part of the mold along the casting direction. In this case, the cooling rate of the melt may be adjusted using at least one of the thermal conductivity of the material forming the body of the mold, the supply flow rate of the cooling medium supplied to the cooling jacket, the supply rate and the type.

First, the melt may be charged into the container 100. In this case, the melt may include phosphor bronze or a copper alloy containing titanium (Ti), chromium (Cr), zirconium (Zr), aluminum (Al), and the like.

Thereafter, casting may be performed while discharging the melt to the mold 200 through the discharge port 110. At this time, the mold 200 may be formed by dividing the body 210 in direct contact with the melt into different materials having different thermal conductivity. For example, the first body 210a in which the initial cooling is performed is formed of at least one of graphite, boron nitride, and zirconium carbide, and the second body 210b in which the intermediate cooling in which the casting is formed is formed by using copper or silicon carbide. can do. In addition, the third body 210c in which the final cooling is performed may be formed of graphite.

The melt discharged to the mold 200 may be cast into a cast while passing through the mold 200. In addition, the cast product cast in the mold 200 may be drawn out of the mold 200. In this case, the casting may be drawn to the outside of the mold 200 through the drawing part 400 disposed in front of the mold 200 with respect to the casting direction. In addition, the castings drawn from the mold 200 may be secondarily cooled by the cooling water sprayed from the cooling unit 300.

On the other hand, in the process of casting the casting, the melt flowing into the mold 200 starts to solidify while being cooled at the first cooling rate in the first body 210a, and more than the first cooling rate in the second body 210b. It can be formed into a casting while cooling rapidly at a high second cooling rate. In this case, the second cooling rate may mean a cooling rate at which the melt can be completely solidified in the second body 210b. In addition, the casting formed in the second body 210b may be transported while being cooled at a third cooling rate in the third body 210c and drawn out of the mold 200. At this time, the melt may be completely solidified while being rapidly cooled in the second body 210b to be formed into a cast. When the solidification is completed while the melt is rapidly cooled in this way, the solidification temperature range decreases to reduce or suppress the occurrence of the solid-liquid coexistence zone in the casting, thereby suppressing or preventing reverse segregation that may occur. In addition, the growth of dendritic crystals in the casting is suppressed, and defects that may be caused by the dendritic crystals can be prevented. In particular, since the second body 210b, in which the melt is substantially solidified, is not formed of graphite, it is possible to prevent the reaction product from being generated by a reaction with a specific component in the melt.

In addition, in order to rapidly increase the cooling rate in the second body 210b, a supply method of the cooling medium supplied to the cooling jacket 220 may be controlled. For example, when the cooling jacket 220 is divided into a first cooling jacket 222a and a second cooling jacket 222b as shown in FIG. 3, the first cooling jacket 222a and the second cooling jacket 222b The cooling medium can be supplied independently. At this time, it is possible to prevent heat exchange between the first cooling jacket 222a and the second cooling jacket 222b by blocking the heat insulating material 230 between the first cooling jacket 222a and the second cooling jacket 222b. have.

Alternatively, the supply speed of the cooling medium supplied to the first cooling jacket 222a and the second cooling jacket 222b may be controlled. That is, the first cooling jacket 222a must maintain the temperature of the second body 210b so that the melt can be rapidly cooled and completely solidified. Accordingly, the cooling medium supplied to the first cooling jacket 222a may be controlled to be supplied faster than the cooling medium supplied to the second cooling jacket 222b.

Alternatively, the type of cooling medium supplied to the first cooling jacket 222a and the second cooling jacket 222b may be changed. That is, a cooling medium having better cooling efficiency than the cooling medium supplied to the second cooling jacket 222b may be supplied to the first cooling jacket 222a. For example, when water is supplied as a cooling medium to the first cooling jacket 222a, air may be supplied as a cooling medium to the second cooling jacket 222b. Alternatively, when helium gas is supplied to the first cooling jacket 222a, water may be supplied to the second cooling jacket 222b.

Hereinafter, an experiment result for examining the quality of a casting cast using the casting apparatus according to an embodiment of the present invention will be described.

For the experiment, a mold was molded using a material having thermal conductivity shown in Table 1 below, and these molds were each applied to a container to cast a cast. At this time, the body constituting the mold was formed by dividing into a first body, a second body and a third body along the casting direction. And Table 2 shows the results of observing the state of the cast and mold (body).

SiO ₂ Refractory black smoke Zirconium carbide
(ZrC) Boron nitride
(BN) nickel
(Ni) Silicon carbide
(SiC) Copper
(Cu) silver
(Ag) Thermal conductivity
(W/m·K) 1.5 24 25 30 90.9 120 397 429

Referring to Table 2 below, in Experimental Examples 1 to 9, the third body was formed of graphite for lubrication of the casting. In addition, the first body and the second body were formed of materials having different thermal conductivity (except Experimental Example 7).

First body Second body Third body Casting results Experimental Example 1 SiO ₂ Refractory
nickel



black smoke Bad Experiment Example 2 Boron nitride (BN) Slightly bad Experiment Example 3 nickel Slightly bad Experiment Example 4 SiO ₂ Refractory
Copper Good Experimental Example 5 Boron nitride (BN) Great Experimental Example 6 nickel Good Experimental Example 7 SiO ₂ Refractory
silver Slightly bad Experimental Example 8 Boron nitride (BN) Slightly bad Experimental Example 9 nickel Bad

According to Table 2, in the case of Experimental Examples 4 to 6 in which the second body is formed of copper, the casting result is shown to be good or excellent. This is because when the second body is formed using copper having a thermal conductivity of 397 W/m·K, solidification is completed as the melt is rapidly cooled in the second body. In particular, in the case of Experimental Example 5 in which the first body was formed of boron nitride having a thermal conductivity of 30 W/m·K, reverse segregation hardly occurred and phenomena such as scratches or abrasions did not occur in the mold, resulting in the best casting results. Is shown. This is because the melt was gently cooled in the first body and more effectively cooled in the second body. On the other hand, in the case of Experimental Example 4, in which the first body was formed of SiO ₂ based refractory material having very low thermal conductivity, some reverse segregation occurred in the casting, indicating good casting results. Since cooling of the melt is hardly performed in the first body, it is assumed that even if the melt is rapidly cooled in the second body, solidification is slightly delayed in the second body, resulting in reverse segregation. In addition, even in the case of Experimental Example 6 in which the first body was formed using nickel having a thermal conductivity of about 90 W/m·K, some dendritic crystals were found in the casting, and good casting results were shown. This is presumed to be due to the fact that the cooling of the melt was promoted in the first body by nickel, which has a somewhat high thermal conductivity, thereby promoting the growth of dendritic crystals.

And in the case of Experimental Examples 1 to 3 in which the second body was formed using nickel having a thermal conductivity of about 90W/m·K, a large amount of reverse segregation was formed in the casting, and a scratching phenomenon occurred on the body, resulting in the casting result. It appears to be slightly poor or poor. This is because reverse segregation occurred in the casting because the second body did not have sufficient thermal conductivity to completely solidify the melt.

In addition, in the case of Experimental Examples 7 to 9 in which the second body was formed of silver with a thermal conductivity exceeding 400W/m·K, no reverse segregation was formed in the cast, but the cast and the second body were severely scratched, The casting result is shown to be slightly poor or poor due to the occurrence of breakage of the casting. This is because the solidification was completed in the first half of the second body adjacent to the first body as the melt was cooled very rapidly by silver having very high thermal conductivity. Accordingly, frictional force was generated between the casting and the second body, causing scratching on the second half of the second body and on the casting. And there was a phenomenon in which the casting was not pulled out properly due to the frictional force and was broken.

In the case of casting the casting by the horizontal casting method as described above, casting can be stably performed and the quality of the casting can be improved by controlling the solidification rate or cooling rate of the melt in the mold.

Meanwhile, FIG. 4 is a view showing a temperature change of a casting according to a material of a mold, and a solidification state of a melt in a second body can be confirmed according to the material of the second body. At this time, in FIGS. 4A to 4D, the first body was formed of boron nitride, and the third body was formed of graphite.

Figure 4 (a) is a case in which the second body is formed of graphite, and Figure 4 (b) is a case in which the second body is formed of zirconium carbide, showing that the melt is solidified in the third body. In this case, there is a problem that reverse segregation may occur due to an increase in the solid-liquid coexistence area in the casting. In addition, in the case of FIG. 4A in which the second body is formed of graphite, there is a problem in that certain components in the melt react with the graphite forming the second body to form carbides in the second body.

On the other hand, (c) of FIG. 4 is a case where the second body is formed of copper, and (d) of FIG. 4 is a case where the second body is formed of silicon carbide, and it can be seen that the solidification of the melt is completed in the second body. . In this case, since solidification is completed while the melt is rapidly cooled, the solid-liquid coexistence area in the casting is reduced, and occurrence of reverse segregation can be suppressed.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and common knowledge in the field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Those who have a will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the technical protection scope of the present invention should be determined by the following claims.

100: container 200: mold
210: body 220: cooling jacket
300: cooling part 400: drawing part

Claims (21)

As a casting mold,
A first body connected to a container capable of receiving the melt and providing a first space for cooling the melt discharged from the container; And
Including; a second body connected to the first body to provide a second space for cooling the melt to form a casting, and to communicate the first space and the second space,
The second body is formed of a material having a higher thermal conductivity than the first body,
The first body is inserted into the container capable of discharging the melt,
The second body is a mold for casting exposed to the outside of the container. The method according to claim 1,
The second body is a mold for casting comprising a material having a thermal conductivity of 5 to 20 times greater than that of the first body. The method according to claim 2,
The first body includes at least one of boron nitride, zirconium carbide and graphite,
The second body is a mold for casting containing at least one of copper and silicon carbide. The method of claim 3,
A third body connected to the second body to provide a third space for forming a movement path of the casting and to communicate the third space and the second space; And
Casting mold comprising a; cooling jacket provided on the outside of the second body and the third body. The method of claim 4,
The third body is a casting mold containing at least one of boron nitride, zirconium carbide, and graphite. The method of claim 5,
The second body is formed to have a length of 2 to 3 times that of the first body,
The third body is a casting mold formed to have a length of 5 to 7 times the first body. The method of claim 6,
The cooling jacket,
A first cooling jacket having a first flow passage defining a moving path of the cooling medium therein, and provided outside the second body; And
Including; a second flow path is formed therein to form a moving path of the cooling medium, a second cooling jacket provided on the outside of the third body, and,
A mold for casting wherein the diameter of the first passage is formed at least larger than the diameter of the second passage. The method of claim 7,
Casting mold having a heat insulating material between the first cooling jacket and the second cooling jacket. As a casting device for casting a casting,
A container that provides a space for accommodating the melt and has an outlet for discharging the melt; And
Including; a mold connected to the outlet to cast a cast by solidifying the melt discharged from the container,
The mold includes different types of materials having different thermal conductivity along the casting direction,
A first body inserted into the outlet; And
A casting apparatus capable of controlling the cooling rate of the melt in the casting direction, including a second body formed of a material having a higher thermal conductivity than the first body and connected to the first body so as to be exposed to the outside of the container. The method of claim 9,
The casting device is connected to the container so that the mold extends in a horizontal direction. The method of claim 10,
The first body is formed of a material having a thermal conductivity of 20 to 40 W / m · K,
The second body is a casting apparatus formed of a material having a thermal conductivity of 100 to 400 W / m · K. The method of claim 11,
Further comprising a third body connected to the second body,
Casting apparatus wherein the third body is formed of a material having a lower thermal conductivity than the second body. The method of claim 12,
The mold,
Including a cooling jacket provided on the outside of the second body and the third body,
A cooling medium supply unit for supplying a cooling medium to the cooling jacket; And
Casting apparatus further comprising a; a control unit for controlling the operation of the cooling medium supply unit to adjust the supply rate of the cooling medium. The method of claim 13,
The cooling jacket,
A first cooling jacket provided on the outside of the second body; And
Including; a second cooling jacket provided on the outside of the third body,
The control unit is a casting apparatus capable of controlling the operation of the cooling medium supply unit to adjust the supply speed of the cooling medium supplied to each of the first cooling jacket and the second cooling jacket. The method of claim 14,
Casting apparatus comprising a heat insulating material between the first cooling jacket and the second cooling jacket. delete delete delete delete delete delete

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