KR20030018661A - Method of the horizontal continious casting in using of the heating mold and the eguipment here of - Google Patents

Abstract

PURPOSE: A method of horizontal continuous casting using heating mold which enables working and filling of molten metal during working even when height of molten metal is not maintained equally to that of the upper part of an extracting part, and an apparatus of horizontal continuous casting using heating mold are provided. CONSTITUTION: The apparatus of horizontal continuous casting using heating mold comprises a melting furnace(10) for melting metal and metal alloy; a heating means(11) for heating the melting furnace; a heat insulating material(20) which is covered around the melting furnace(10) to insulate heat; a molten metal height adjusting device(30) vertically movably installed inside the melting furnace(10); a mold(40) connected to the melting furnace(10) to penetrate the heat insulating material(20); second heating means(41) for heating the mold(40); an extracted material cooling means(50) correspondingly formed to the mold(40); a dummy bar(60) which is freely movably inserted into the mold(40) to control flow of molten metal, and at the rear of which a leading in and drawing out means(61) is installed; a thermocouple(12) mounted on the melting furnace(10) to measure temperature of molten metal; and a thermocouple(42) inserted into the mold(40) to measure temperature of the inner part of the mold(40).

Description

Method of the horizontal continious casting in using of the heating mold and the eguipment here of}

The present invention relates to a heating casting type horizontal continuous casting device and a casting method, and in particular, to place the solidification interface of the metal inside the mold during casting, forming a cooling means close to the end of the mold to form a one-way solidification structure The present invention relates to a method for casting a metal having the same and an apparatus thereof.

As the devices used in recent years by the advancement of the industry and the rapid development of the electronics industry are miniaturized with precision, the metal materials used therein tend to be remarkably miniaturized and advanced.

In particular, as the bonding wire used in the circuit of a computer, an ultrafine wire of about 10 µm to 20 µm is used.

In order to obtain such a fine wire, it is required that there is no macro segregation, non-metallic inclusions, bubbles, etc. in the ingot, which is the original material, and a metal material having few or no grain boundaries that facilitates segregation of impurities is required.

As a method for obtaining such a metal material, a continuous casting method is used.

However, the general continuous casting method uses a water-cooled cooling mold, so that a stable solidification angle is formed on the mold wall during casting, so that the columnar tablet is grown vertically from the mold wall toward the center, and thus shrinkage holes and bubbles are formed in the center of the ingot. There existed a problem that a back | light etc. generate | occur | produced, or a macro segregation was reached and the target material was not obtained.

In order to solve this problem, a continuous casting method using a heating mold has been attempted.

The continuous casting method using a heating mold keeps the mold inner wall above the melt temperature to prevent solidification nucleation on the mold wall surface and controls the solidification of the molten metal at the mold outlet end, unlike the cooling mold. This smoothness and beauty, as well as ingots without defects such as shrinkage pores or pores therein, can be obtained, and one-way coagulation materials can be continuously obtained without being limited in length or shape.

In particular, when the casting method is a horizontal method, small precision parts such as bonding wires of computer circuits and cables of acoustic devices can be easily obtained.

That is, the horizontal continuous casting method using a heating mold can continuously obtain unidirectional solidified materials or single crystal materials without any internal defects or surface defects such as inclusions, shrinkage holes, and the like without limitation of length. The bar can be manufactured without breaking.

However, the conventional one-way solidification technique using the heating mold has a constraint that the height of the molten metal and the upper end of the withdrawal portion to be drawn out should be horizontal during the work.

This is because when gravity is applied to the molten metal passing through the end of the mold, that is, when the height of the molten metal is formed higher than that of the molten portion, breakout phenomenon occurs in which the molten portion is scattered by the molten metal pressure. If it is lower than the height of the lead portion, the molten metal is not drawn out smoothly so that the lead portion is broken.

For this reason, re-supply of the molten metal is impossible during the operation, so that only a certain amount of the molten metal can be worked at a time, and the work must be re-supplied after the work is stopped.

The technical problem to be achieved by the present invention is that it is possible to work without having to maintain the height of the molten metal at the same time as the top height of the withdrawal at all times in order to solve the above-mentioned problems, the heating casting type horizontal continuous casting apparatus capable of filling the molten metal during operation and The present invention provides a casting method.

1 is a schematic view of a heating casting type horizontal continuous casting apparatus of the present invention,

2 is a cross-sectional view of a cooling apparatus according to the present invention,

3 is a measurement table measuring the temperature in the mold according to the mold distance of the present invention,

4 is a view of the A1 alloy withdrawal according to the present invention,

5 is a microscopic cross-sectional structure of the A1 alloy extract according to the present invention

※ Explanation about main code in drawing.

10: melting furnace, 11: heating means,

12: thermocouple, 20: heat insulating material,

30: molten metal height adjusting device, 31: locking part,

32: handle, 40: mold,

41: second heating means, 42: thermocouple,

50 cooling means, 51 cooling water injector,

52 gas injector, 53 tubular water cooling bath,

54: projection jaw, 55: coolant receiver,

56: drain, 60: dummy bar,

61: pinch roll, 70: withdrawal,

80: molten metal.

The present invention for achieving the above technical problem is a heating means for heating the melting furnace and the melting furnace, the heat insulating material surrounding the melting furnace and the insulation, the molten metal height adjusting device which is installed to move up and down in the melting furnace, and in the melting furnace A mold having a mold communicating with the heat insulating material, a heating means for heating the mold, a drawer cooling means formed on an outer side corresponding to the mold, and an entrance and exit freely inserted into the mold, and a dummy having a drawing and drawing means at a rear end thereof. And a thermocouple mounted on the melting furnace to measure the temperature of the molten metal and a thermocouple inserted into the mold to measure the temperature inside the mold.

Hereinafter will be described in detail with the drawings according to an embodiment of the present invention.

1 is a schematic view of a heating casting type horizontal continuous casting apparatus of the present invention.

Outside the graphite furnace 10 for melting metal, a heating element 11 for heating the graphite furnace 10 is provided.

Outside the graphite furnace 10 and the heating element 11, the refractory brick 20 as a heat insulating material is constructed, and the lower side is locked to the molten metal 80 in the graphite furnace 10 so that the molten metal is locked according to the degree of locking. A molten metal height adjusting device 30 including a portion 31 and a handle 32 connected to the locking portion 31 is installed.

The molten metal height adjusting device 30 may be moved up and down by an apparatus or may be moved by an operator.

A graphite mold 40 communicating with the graphite furnace 10 and penetrating through the refractory brick 20 is installed at the side of the graphite furnace 10, and outside the graphite mold 40 at the refractory brick 20. A second heating element 41 is formed to enclose and heat the graphite mold 40, and a taper is formed at an angle of 0.1 to 10 degrees over 30 mm inwardly from the string end of the mold.

This taper prevents cracking of the metal due to the frictional force by reducing the frictional force that is produced by the solidification shrinkage when the molten metal solidifies in the graphite mold 40 and the graphite mold 40.

2 is a cross-sectional view of a cooling device according to the present invention.

Cooling means 50 is formed on the outer side adjacent to the graphite mold 40, the cooling means 40 is a cooling water sprayer for injecting the cooling water to the withdrawn 70 drawn from the graphite mold (40) A 51 is installed and a gas injector 52 is installed to block the injected coolant from flowing into the graphite mold 40 in front of the coolant injector 51 to inject Ar gas into the extract 70. .

A tubular water cooling bath 53 is coupled to the cooling water injector 51, and a protruding jaw 54 is formed at the end of the tubular water cooling bath 53 so that the coolant sprayed by the cooling water injector 51 is drawn through the drawer 70. Temporarily stored in the tubular water cooling bath 53 cools the drawer 70 and is discharged outward through a gap between the projection jaw 54 and the drawer 70.

Cooling water receiver 55 is coupled to the tubular water cooling bath 53 outside, and the drain port 56 is installed below the cooling water receiver 55.

In addition, the graphite mold 40 is provided with a dummy bar 60 that fits freely into the graphite mold 40 and opens and closes the passage of the molten metal. A dummy bar 60 is disposed at the end of the dummy bar 60. ), A pinch roll 61 for pushing and withdrawing into the inside is formed.

In addition, a thermocouple 12 for measuring the temperature of the molten metal 80 is mounted in the graphite furnace 10, and the thermocouple 42 for measuring the temperature in the mold along the drawing direction is spaced 10 mm apart in the graphite mold 40. Is formed.

The above-described heating casting type horizontal continuous casting apparatus performs one-way continuous casting while maintaining the solidification interface inside the mold.

In the process of forming the solidification interface in the mold 40, the nucleation can be made from the mold wall surface by friction with the mold wall surface. However, such nucleation is prevented by the use of the adjacent cooling device and the withdrawal speed.

If the flow of heat is allowed to flow only in one direction parallel to the extraction direction by the cooling device, the solidification nuclei initially generated grow in the opposite direction to the extraction direction.

Crystals coinciding with the direction of thermal movement are eroded by the crystal growth priority direction, which is the crystal growth characteristic of the metal, and only crystals having the preferential growth direction are continuously grown according to the direction of thermal movement.

This growth of crystals leads to continuous one-way growth with only a few crystals remaining, and finally only one crystal remains, which allows continuous casting of single crystal products.

Hereinafter, an embodiment of the present invention will be described.

<Example 1>

It was carried out using a horizontal continuous casting apparatus as shown in Figure 1 was used as the molten metal A1-Si alloy. After loading 2 kg of A1-1Wt% Si alloy into the graphite furnace 10, the molten metal height adjusting device 30 was placed on the graphite furnace 10, and the graphite furnace was heated to dissolve the A1-Si alloy.

After the A1-Si alloy was dissolved, the dummy bar 60 was introduced into the graphite furnace 10 through the graphite running 40 to 20 mm, and the temperature of the molten metal was maintained at 720 ° C. and the graphite mold 40 was also heated. It was kept at 750 ° C.

While the molten metal temperature and the graphite mold temperature are maintained at 720 ° C., the molten metal height adjusting device 30 is lowered into the molten metal so that the molten metal height is adjusted to be 30 mm higher than that of the graphite mold 40. 40) was drawn at a rate of 30 mm / min to allow the molten metal 80 to flow into the graphite mold 40 while measuring the temperature of each part inside the graphite mold to form a solid and liquid interface at which solidification of the A1-Si alloy began. It was to be formed between the distance 10-20mm. That is, solidification was started so that 620 ° C, the temperature at which the solid and liquid interfaces were formed, was maintained at the mold distance of 10 to 20 mm.

3 is a table measuring the temperature in the mold according to the mold distance, Figure 4 is a view of the A1 alloy withdrawal outline according to Example 1 of the present invention.

When the inside of the mold was maintained at the temperature as shown in FIG. 3, the continuous casting was performed by removing the dummy bar 60, and as a result of observing the cast extract 70, the bar with a beautiful surface as shown in FIG. 4 was able to be drawn out. .

Of course, as the continuous casting operation is performed, the molten metal is lowered, but at this time, the molten metal is lowered by lowering the molten metal height adjusting device 30 to maintain the molten metal at a predetermined level, thereby casting.

In the table of FIG. 3, the temperature is lowered at the mold distance less than 30 mm due to the heat conduction by the cooling means 50 adjacent to the graphite mold, and the temperature rise at the mold distance of 50 mm or more is caused by the heating of the graphite mold 40. Is due.

FIG. 5 is a microscopic cross-sectional structure showing the cross section of the bar of FIG. 4, and initially a polycrystalline bar is taken out.

It can be seen that the crystal grows in one direction, turns into a unidirectional crystal composed of several crystals, and later a single crystal of single-direction bar is drawn out.

Hereinafter, the heating casting type horizontal continuous casting method of the present invention will be described.

The present invention comprises the steps of charging a metal or alloy to be dissolved in the melting furnace 10 and heating to dissolve, the step of dissolving the metal and inserting the dummy bar 60 into the melting furnace 10 through the mold 40; Heating the mold 40 higher than the melting temperature; and, when the metal is completely dissolved, inserting the molten metal height adjusting device 30 into the molten metal to form the height of the molten metal 30 mm higher than the mold, and inserting the molten metal into the melting furnace 10. And slowly withdrawing the dummy bar 60 through the mold 40 to introduce the molten metal into the mold 40 to form a solid and liquid interface of the metal at a mold distance of 10 to 20 mm, and the dummy bar 60. Is completely drawn out from the mold 40 and the cooling means 50 and the gas injector 52 are operated to block the inflow of the mold 40 of the cooling water and to cool the drawn metal. Withdrawn, but gradually the decision grows in one direction A single crystal bar in one direction is taken out.

The above-described casting method can be used for the production of pure metal, metal alloy bar, and the like, and especially for the production of A1 alloy rods for electronic and precision mechanical parts.

The present invention can easily adjust the height of the molten metal during the operation, it is possible to work continuously without maintaining the height of the molten metal the same as the height of the drawer at all times, it is possible to continuously cast work, filling the molten metal during the operation can be continuous work In addition, the conventional method of melting, casting, hot working, cold working, heat treatment, and post-treatment may be omitted, thereby easily manufacturing a hot single crystal product.

Claims (5)

A melting furnace 10 for dissolving metal and metal alloy, a heating means 11 for heating the melting furnace 10, a heat insulator 20 surrounding the melting furnace 10 and insulated, and an image in the melting furnace 10. , A molten metal height adjusting device 30 installed to move downward, a mold 40 communicating with the melting furnace 10 and penetrating the heat insulating material 20, and second heating means 41 for heating the mold 40. ), The drawer cooling means 50 formed corresponding to the mold 40, and the inlet and outlet are freely fitted into the mold 40 to control the flow of the molten metal, and the inlet and drawout means 61 are provided at the rear end. A dummy bar 60 and a thermocouple 12 mounted in the melting furnace 10 and inserted into the mold 40 and a thermocouple 42 inserted into the mold 40 to measure the temperature inside the mold 40. Heating casting type horizontal continuous casting device, characterized in that consisting of. The method of claim 1, The end portion of the mold 40, the taper is formed horizontally casted at an angle of 0.1 to 10 ° over 30 mm inwardly. The method of claim 1, The cooling means 50 is a heating column, characterized in that consisting of a tubular water cooling bath 53, a passage through which the withdrawal material 70 passes, and a cooling water sprayer 51 installed in front of the tubular water cooling bath to spray cooling water. Type Horizontal inner casting machine. The method according to claim 1 or 3, Heat casting type horizontal continuous casting device, characterized in that the front surface of the cooling water injector (51) of the cooling means 50 is formed with a gas injector (52) for injecting the gas to block the inlet of the mold (40). Charging the metal to be dissolved in the melting furnace 10 and heating the molten metal, dissolving the metal and inserting the dummy bar 60 into the melting furnace 10 through the mold 40, and heating the mold. And forming the molten metal height higher than the mold by using the molten metal height adjusting device 30, and gradually pulling the dummy bar 60 inserted into the melting furnace 10 through the mold 40 to bring the molten metal to the mold 40. Inflow, but forming a solid and liquid interface of the metal between the mold distance 10 ~ 20㎜ to prevent the outflow of the molten metal, and withdraw the dummy bar 60 from the mold 40 completely to operate the cooling means 50 Heat casting type horizontal continuous casting method, characterized in that consisting of the step of cooling the drawn metal.