KR100865658B1 - Electromagnetic stirring continuous casting device and continuous casting method using the same - Google Patents

Abstract

An electromagnetic stirring continuous casting apparatus and a continuous casting method using the same provide a molten metal molten metal in a space extending in one direction inside the mold. Subsequently, the molten metal injected into the mold is indirectly cooled with cooling water circulating outside of the mold, and electromagnetic stirring is performed to form a metal in a solid state. Thereafter, cooling water is directly supplied by supplying cooling water to the cast product formed from the reaction solid state metal and exiting the mold.

Description

Electromagnetic Stirring Continuous Casting Apparatus and Continuous Casting Method Using The Same {APPARATUS FOR PERFORMING CONTINUOUS CASTING BY ELECTROMAGNETIC STIRRING AND CONTINUOUS CASTING METHOD USING THE SAME}

The present invention relates to an electromagnetic stirring continuous casting device and a continuous casting method using the same. In more detail, the present invention relates to an electromagnetic stirring continuous casting device excellent in cooling efficiency and a continuous casting method using the same.

The continuous casting process is a process of continuously injecting molten metal into a mold and then solidifying to produce an ingot having a relatively long shape. In the continuous casting process, the molten metal is rapidly cooled, so the characteristics of the product are excellent and the yield is high. In addition, the product can be directly forged in a subsequent process, thereby greatly reducing the manufacturing time.

A method of continuously casting a molten metal using electromagnetic force has been studied. When electromagnetic force is applied to the molten metal, the coagulation structure can be finely controlled, and thus an ingot having excellent characteristics can be produced. In addition, the process can be efficiently controlled by applying electromagnetic force during continuous casting.

One embodiment of the present invention provides an electromagnetic stirring continuous casting apparatus capable of continuous casting by applying electromagnetic stirring.

One embodiment of the present invention provides a continuous casting method using the electromagnetic stirring continuous casting device.

According to an embodiment of the present invention, an electromagnetic stirring continuous casting apparatus used in a continuous casting process includes a mold having a space extending in one direction therein and an electromagnetic generator surrounding the mold. The molten metal is injected into the space to make a cast product and the electromagnetic generator stirs the molten metal. The mold is formed between a first mold part in contact with the molten metal, a second mold part surrounding the first mold part, the first mold part and the second mold part, and circulates a cooling water to cool the metal melt. And a plurality of nozzle portions in communication with the cooling channel for injecting the cooling water into the cast product exiting the first mold portion. The plurality of nozzle parts includes a first nozzle part having a ring-shaped first nozzle hole through which the coolant is injected, and a second nozzle part having a ring-shaped second nozzle hole having a diameter larger than the diameter of the first nozzle hole. . The first nozzle portion and the second nozzle portion form an angle of 30 degrees to 60 degrees.

The direction in which the plurality of nozzle portions extend may form an acute angle with the surface of the cast product.

Cooling water sprayed from the first nozzle portion may be reflected while colliding with the surface of the cast product, and another coolant sprayed from the second nozzle portion may block an outflow of the reflected cooling water.

The first mold part may be made of graphite or stainless steel. Here, the molten metal may include a solid metal and a liquid metal, and the solid metal and the liquid metal may be agitated by the electromagnetic generated from the electromagnetic generator.

The space includes a first space portion including the inlet of the molten metal and the first space portion, and a second space portion through which the metal melt flows out into the cast product, wherein the diameter of the second space portion is equal to the first space portion. It may be larger than the diameter of one space part. A heat insulation member may be formed on an inner surface of the first space portion, and a graphite member may be formed on an inner surface of the second space portion. The cast product may be formed of equiaxed tissue.

According to one embodiment of the invention a continuous casting method is provided. Specifically, a molten metal molten metal is provided in a space extending in one direction inside the mold. Subsequently, the molten metal injected into the mold is indirectly cooled with cooling water circulating outside of the mold to form a metal in a solid state by electromagnetic stirring. Thereafter, cooling water is directly supplied by supplying cooling water to the cast product formed from the reaction solid state metal and exiting the mold.

The space may be partitioned into a first space portion into which the molten metal is injected, and a second space portion communicating with the first space portion and through which a cast product manufactured from the metal melt flows out.

The mold includes a first mold part in contact with the molten metal and a second mold part 10b surrounding the first mold part, and a cooling channel is formed between the first mold part and the second mold part. The cooling water may circulate in the cooling channel.

Direct cooling may be performed by supplying coolant provided from the cooling channel to the cast product using at least two nozzle portions.

The nozzle parts communicate with an end portion of the cooling channel, and the nozzle parts include a first nozzle part having a ring-shaped first nozzle hole into which the cooling water is injected and a ring-shaped agent having a diameter larger than the diameter of the first nozzle hole. It may include a second nozzle portion having two nozzle holes.

Cooling water injected from the first nozzle portion may be reflected while colliding with the surface of the cast product, and another coolant sprayed from the second nozzle portion may block an outflow of the reflected cooling water. The cast product may be formed of equiaxed tissue.

According to embodiments of the present invention, it is possible to maximize the stirring effect by using a mold for magnetic stir horizontal continuous casting, it is possible to control the microstructure through a fast cooling rate. In addition, by employing an indirect cooling method and a direct cooling method at the same time, it is possible to increase the cooling efficiency and effectively obtain a fine equiaxed structure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to the following embodiments. Therefore, those skilled in the art may implement the present invention in various other forms without departing from the technical spirit of the present invention. In the accompanying drawings, the dimensions of the components are enlarged than actual for clarity of the invention. When components are referred to as "first" and "second", they are not intended to limit these components but merely to distinguish between the components. Thus, it can be used selectively or interchangeably for the "first" and "second" components, respectively.

Electromagnetic stirring continuous casting device

1 is a perspective view for explaining the electromagnetic stirring continuous casting apparatus 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

1 and 2, the electromagnetic stirring continuous casting apparatus 100 includes a mold 10 having a space extending in one direction therein and an electromagnetic generator 20 (electro magentric stirrer) surrounding the mold 10. Electromagnetic stirring continuous casting device 100 is used to manufacture a cast product by continuously stirring and cooling the molten metal injected into the space.

The mold 10 includes a first mold portion 10a in contact with the molten metal and a second mold portion 10b surrounding the first mold portion 10a. The mold 10 may be formed using a material having a high thermal conductivity and a small influence on the electromagnetic flux density. Examples of the material include graphite, stainless steel, and the like.

As described above, the mold 10 has a space extending in one direction therein. The space includes a first space portion into which the molten metal is injected, and a second space portion in communication with the first space portion, through which a cast product manufactured from the metal melt flows out.

Specifically, the molten metal is introduced into the first space portion. The electromagnetic generator 20 is provided to surround the outside of the second mold part 10b so as to surround the vicinity of the boundary region to which the first space part and the second space part are connected. In the vicinity of the boundary region, agitation is relatively active, thereby forming a metal in a reaction state. And finally, the cast product of a solid state will come out from a 2nd space part.

Here, the heat insulation member 30 is formed in the inner wall portion of the mold 10 corresponding to the first space portion. The heat insulating member 30 serves to narrow the inlet of the first space portion into which the metal melt is injected so that the stirring force of the stirred metal melt is transmitted to the outside of the mold 10 and the stirring force is not weakened. It can be formed using.

The graphite member 40 may be formed on the inner wall portion of the mold 10 corresponding to the second space portion. The graphite member 40 serves to reduce the friction between the mold 10 and the cast product. The thickness of the graphite member 40 is preferably less than the thickness of the heat insulating member 30, which facilitates the flow of the molten metal and is caused by the electromagnetic generator 20 between the first space portion and the second space portion. This is to facilitate stirring.

As described above, since the heat insulation member 30 and the graphite member 40 are formed on inner walls of the first space portion and the second space portion, respectively, the first space portion has a first width W1 and the second space portion. The space portion has a second width W2 that is substantially larger than the first width W1.

A cooling channel 50 is formed between the first mold portion 10a and the second mold portion 10b. Since the cooling water circulates in the cooling channel 50, the molten metal is indirectly cooled by the cooling channel 50.

In addition, at least two nozzle portions 60 are formed in communication with an end portion of the cooling channel 50 to inject the cooling water supplied from the cooling channel 50 to the cast product exiting from the first mold portion 10a.

Specifically, the plurality of nozzle parts 60 has a first nozzle part 60a having a ring-shaped first nozzle hole through which the coolant is injected, and a ring-shaped second nozzle hole having a diameter larger than the diameter of the first nozzle hole. It may include a second nozzle unit 60b.

Here, the first nozzle part 60a and the second nozzle part 60b extend from the end of the cooling channel 50 in the direction toward the cast product. Specifically, as shown in FIG. 2, the extending direction of the first nozzle part 60a and the extending direction of the second nozzle part 60b are respectively the first acute angle θ1 and the first acute angle (with respect to the surface of the cast product). A second acute angle θ2 is made smaller than θ1).

As schematically shown in FIG. 2, the coolant sprayed from the first nozzle portion 60a is reflected while colliding with the surface of the cast product, and another coolant sprayed from the second nozzle portion 60b is reflected water It will block the outflow of the

Here, when the angle between the first nozzle unit 60a and the second nozzle unit 60b is less than about 30 °, the water streams sprayed from the first nozzle unit 60a and the second nozzle unit 60b are combined into one stem. Can be. On the other hand, when the angle between the first nozzle portion 60a and the second nozzle portion 60b exceeds about 60 °, the water stream sprayed from the second nozzle portion 60b is sprayed from the first nozzle portion 60a. And then does not effectively block the outflow of coolant reflected from the surface of the cast product. Therefore, the angle between the first nozzle unit 60a and the second nozzle unit 60b may be about 30 ° to about 60 °.

Continuous casting method

3 is a flowchart illustrating a method of manufacturing a cast product according to an embodiment of the present invention. More specifically, FIG. 3 is a flowchart illustrating a method of manufacturing a cast product using the electromagnetic stirring continuous casting apparatus 100 shown in FIGS. 1 and 2.

1 to 3, a molten metal molten metal is provided in a space extending in one direction in the mold 10 (S10).

Specifically, the space extending in one direction inside the mold 10 communicates with the first space portion into which the molten metal of the liquid state is injected and the first space portion, and the cast product manufactured from the metal melt flows out. It may be divided into a second space portion, the liquid metal molten metal is introduced into the first space portion.

Subsequently, the molten metal injected into the mold 10 is electromagnetically stirred while indirectly cooling the cooling water circulating outside the mold 10 (S20). Specifically, the mold 10 includes a first mold portion 10a in contact with the molten metal and a second mold portion 10b surrounding the first mold portion 10a, and the first mold portion 10a and the second mold portion 10b. Cooling channels 50 are formed between the mold portions 10b. Since cooling water is circulated in the cooling channel 50, the molten metal may be indirectly cooled by the cooling channel 50.

In addition, electromagnetic agitation is performed by the electromagnetic generator 20 surrounding the second mold part 10b of the mold 10 to form a metal in a reaction state.

Subsequently, cooling water is directly supplied by supplying cooling water to the cast product formed from the metal in the reaction solid state and exiting from the second space part of the mold 10 (S30).

Specifically, the coolant is supplied to the cast product using at least two nozzle parts 60. The nozzle portions 60 communicate with the end of the cooling channel 50 to inject the cooling water supplied from the cooling channel 50 to the cast product exiting from the first mold portion 10a.

The plurality of nozzle parts 60 includes a first nozzle part 60a having a ring-shaped first nozzle hole through which the coolant is injected and a second nozzle hole having a ring-shaped second nozzle hole having a diameter larger than the diameter of the first nozzle hole. The nozzle unit 60b may be included. Here, the coolant jetted from the first nozzle part 60a is reflected while colliding with the surface of the cast product, and another coolant jetted from the second nozzle part 60b blocks the outflow of the reflected coolant.

As described above, the liquid metal molten metal introduced into the mold 10 is formed of a metal in a solid state by indirect cooling by the cooling channel 50 and electromagnetic stirring by the electromagnetic generator 20. More specifically, the solid-liquid coexistence zone is formed by cooling by the cooling channel 50 and stirring by the electric generator 20, and the dendritic tissue is changed into a fine equiaxed crystal structure. And the metal in the solid state is to be produced as a cast product by direct cooling by the nozzle unit 60 while exiting the mold (10).

Magnetic flux density  Related experiment

After measuring the magnetic flux density by distinguishing between the case of installing the mold of the electromagnetic stirring continuous casting apparatus described in Figures 1 and 2 and not installed, the results are shown in Table 1 and FIG.

TABLE 1

Referring to Table 1 and FIG. 4, it can be seen that the magnetic flux density value is relatively smaller when the mold is installed than when the mold is not installed.

Billet  Produce

The billets were prepared by stirring using electromagnetic agitation as described in FIG. 3 and by direct and indirect cooling. Specifically, electromagnetic agitation was performed as a stirring means, and a billet was manufactured by using a mold having a graphite member and a heat insulating member formed on an inner surface thereof, and having cooling channels and first and second nozzle parts formed thereon.

Figure 5 is a photograph of the outer surface of the billet prepared by stirring using an electromagnetic stirrer. FIG. 6 is a photograph of a longitudinal section of the billet illustrated in FIG. 5. FIG. 7 is a photograph of a cross section of the billet illustrated in FIG. 5.

5 to 7, it can be seen that the inside of the billet has a fine equiaxed structure, because electromagnetic stirring and indirect and direct cooling are effectively performed.

Although described with reference to the embodiments of the present invention as described above, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated.

1 is a perspective view for explaining an electromagnetic stirring continuous casting apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

3 is a flowchart illustrating a method of manufacturing a cast product according to an embodiment of the present invention.

4 is a graph showing the results of a magnetic flux density experiment.

Figure 5 is a photograph of the outer surface of the billet prepared by stirring using an electromagnetic stirrer.

FIG. 6 is a photograph of a longitudinal section of the billet illustrated in FIG. 5.

FIG. 7 is a photograph of a cross section of the billet illustrated in FIG. 5.

Claims (16)

A mold having a space extending in one direction therein; And An electromagnetic generator surrounding the mold, A molten metal is injected into the space to make a cast product, and the electromagnetic generator stirs the molten metal, The mold is: A first mold part in contact with the molten metal; A second mold portion surrounding the first mold portion; A cooling channel formed between the first mold part and the second mold part to circulate cooling water to indirectly cool the molten metal; And A plurality of nozzle portions in communication with the cooling channels for direct cooling by spraying the cooling water onto the cast product exiting the first mold portion, The plurality of nozzle portions are: A first nozzle unit having a ring-shaped first nozzle hole through which the coolant is injected; And It includes a second nozzle portion having a ring-shaped second nozzle hole having a diameter larger than the diameter of the first nozzle hole, The first nozzle portion and the second nozzle portion are formed at an angle of 30 degrees to 60 degrees, and the coolant sprayed from the first nozzle portion is reflected while colliding with the surface of the cast product, and another sprayed from the second nozzle portion Electromagnetic stirring continuous casting device used for continuous casting of coolant to block the outflow of the reflected coolant. The method of claim 1, Electromagnetic stirring continuous casting device in which the direction in which the plurality of nozzle portions extend forms an acute angle with the surface of the cast product. delete The method of claim 1, And said first mold part is made of graphite or stainless steel. The method of claim 4, wherein The molten metal includes a solid metal and a liquid metal, and the solid metal and the liquid metal are stirred by electromagnetic generated from the electromagnetic generator. The method of claim 1, The space is: A first space part including an inlet of the molten metal; And A second space part connected to the first space part and allowing the molten metal to flow out of the cast product; An electromagnetic stirring continuous casting device, wherein the diameter of the second space portion is larger than the diameter of the first space portion. The method of claim 6, Electromagnetic stirring continuous casting device, the heat insulating member is formed on the inner surface of the first space. The method of claim 6, Electromagnetic stirring continuous casting device, the graphite member is formed on the inner surface of the second space portion. The method of claim 1, The cast product is an electromagnetic casting device formed of equiaxed crystal structure. Providing a molten metal in a liquid state to a space extending in one direction inside the mold; Forming a metal in a solid state by electromagnetic stirring while indirectly cooling the molten metal injected into the mold through cooling water circulating outside the mold; And Direct cooling by supplying coolant to the cast product formed from the solid state metal and exiting the mold; The mold includes a first mold part in contact with the molten metal and a second mold part surrounding the first mold part, a cooling channel is formed between the first mold part and the second mold part, and the coolant is Circulate within the cooling channel, The direct cooling may include supplying cooling water provided from the cooling channel to the cast product using at least two nozzle portions, The nozzle parts communicate with an end of the cooling channel, and the nozzle parts include a first nozzle part having a ring-shaped first nozzle hole into which the cooling water is injected and a ring-shaped agent having a diameter larger than the diameter of the first nozzle hole. Including a second nozzle portion having two nozzle holes, The first nozzle portion and the second nozzle portion are formed at an angle of 30 degrees to 60 degrees, and the coolant sprayed from the first nozzle portion is reflected while colliding with the surface of the cast product, and another sprayed from the second nozzle portion A continuous casting method in which cooling water blocks an external outflow of the reflected cooling water. The method of claim 10, And the space is divided into a first space portion into which the molten metal is injected, and a second space portion in communication with the first space portion, through which a cast product manufactured from the metal melt flows out. delete delete delete delete The method of claim 10, And the cast product is formed into equiaxed crystal structure.

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