KR100367453B1 - Continuous Casting Mold with Gate and Gas curtain for the Metal-Casting Process - Google Patents

Abstract

The present invention relates to a semi-continuous casting apparatus equipped with a gate and a gas curtain, and more particularly, to maintain the airtightness of molten molten metal in a melting furnace, and to start the operation of the semi-continuous casting, during the work and the completion of the work. The present invention relates to a casting apparatus having a gate in the mold apparatus and injecting reducing gas into the mold apparatus in order to block the inflow of external air in the mold apparatus.

Semi-continuous casting device equipped with a gate and a gas curtain of the present invention has a passage through which the Kate 104, 105 can be inserted between the molten metal inlet 103 and the respective cooling water pipes 108, and through the passage. The upper gate 104 and the lower gate 105 are inserted into the mold apparatus. On the other hand, in order to prevent impurities from outside air from flowing into the mold apparatus other than the gates 104 and 105, a deoxidation gas inlet 106 is installed between the mold apparatuses in which the gates 104 and 105 are located. It features.

The present invention is provided with a gate capable of blocking the external atmosphere in the mold in order to effectively maintain the airtight with the external atmosphere during the semi-continuous casting process, in particular semi-continuous casting process of anoxic copper throughout the operation, when the mold part is opened and closed It is an object of the present invention to provide a casting apparatus for metal casting with a gate capable of suppressing the inflow of impurity gas from the back and casting an oxygen-free copper of reproducible good quality.

Description

Continuous Casting Mold with Gate and Gas curtain for the Metal-Casting Process}

The present invention relates to a semi-continuous casting apparatus equipped with a gate and a gas curtain, and more particularly, to maintain the airtightness of molten molten metal in a melting furnace, and to start the operation of the semi-continuous casting, during the work and the completion of the work. The present invention relates to a casting apparatus having a gate in the mold apparatus and injecting reducing gas into the mold apparatus in order to block the inflow of external air in the mold apparatus.

The casting process of metal is slightly different depending on materials and manufacturers such as steel and non-ferrous metal, but generally it is based on continuous casting. It is transferred to a heating furnace for heating, and the melt is poured into a cooling mold by using a stopper or a nozzle with a tundish, and the molten metal is solidified in the cooling mold to form various shapes such as slabs and billets for rolling. Process it.

Meanwhile, a general cross-sectional view of the above-mentioned cooling mold or water-cooled mold is shown in FIG. 1, and as shown in FIG. 1, the molten metal fills the lower end of the mold so that the molten metal can solidify without spilling. When the mold reaches a certain height, the slab descends at a constant speed to cast the slab. Casting conditions such as casting speed and amount of cooling water should be considered according to the quality of the slab to be cast. To prevent sticking phenomenon between the mold and the cast, the mold vibrates in the vertical direction. In order to reduce the friction force between the oil (oil) or mold flux (mold flux) is applied to the mold is used. At this time, cooling in the mold including the cooling water pipe is called primary cooling, and cooling water suitable for casting conditions from a nozzle capable of taking out the heat of the cast from directly under the mold and dispersing water to completely solidify. Spraying is called secondary cooling. Types of molds can be divided into cooling molds and heating molds. Cooling molds are widely used. In recent years, onocasting is used to manufacture materials having no shrinkage holes, bubbles, impurities, and inclusions on the surface and inside. Heating molds such as ohno casting are also proposed.

In the case of conventional copper and copper alloy, both continuous casting and semi-continuous casting use a mold of the type shown in FIG. 1 when manufacturing a product which is not significantly affected by external atmosphere. However, for products whose quality is greatly affected by the inflow of external atmosphere, such as oxygen-free copper (OFC), it is important to maintain the confidentiality of the external atmosphere. do. In the continuous casting method, since the slab is continuously formed, it is less likely to flow into the casting apparatus of the external atmosphere, but when manufacturing the slab discontinuously, such as semi-continuous casting, when working with the mold as shown in FIG. Inflow of the atmosphere occurs. In addition, when the upper part of the slab shrinks during solidification and exits the mold, the inflow of external air becomes larger. In particular, in the semi-continuous casting of anoxic copper, the conventional cooling molding apparatus must maintain the airtightness of the casting apparatus for the next operation from the impurity gas such as oxygen and moisture in the external atmosphere for the next operation. There is a problem that is not suitable in the semi-continuous casting of the oxygen-free copper.

In general, oxygen-free copper (OFC) refers to pure copper with less than 10 ppm of oxygen dissolved in copper and maintains purity of 99.99%. According to C-101 standard and C-1010 standard of Japanese Industrial Standard, oxygen dissolved amount is 4ppm or less, and according to C-102 and C-1020 standard of other countries, oxygen dissolved amount in copper is 10 ppm or less. . Oxygen-free copper casting method is made by using copper as a raw material to reduce oxygen dissolved amount by using deoxidizer and deoxidizing gas while blocking the inflow of oxygen into the outside air by total continuous molten metal casting equipment. The vacuum dissolving method in which the concentration of oxygen is controlled and cast is generally known by a reduction melting method and a vacuum degassing treatment of 10 Torr or less according to Japanese Patent Application Laid-open No. Hei 9-119843. The reduction dissolution method can be divided into a hydrogen gas method and a carbon monoxide (CO) gas method, and a method in which a vacuum dissolution method and a reduction dissolution method are mixed is also used. The reduction melting method is the most widely used casting method of the oxygen-free copper, and the continuous casting method is most of the casting method. However, the continuous casting method is not suitable for producing small quantities of various products with excellent characteristics, and the apparatus is complicated and the apparatus cost becomes very high. Therefore, in order to solve this problem, a semi-continuous casting method should be adopted. Problems with contact with the outside atmosphere occur in the mold part. In other words, in continuous casting, the slab is continuously discharged downward, which reduces the possibility of inflow of external air into the mold.However, in semi-continuous casting, the slab is discharged without closing the stopper and injecting molten copper after producing the slab of a certain length. The stopper is closed until the next process, and after the slab is discharged, the outside air is filled in the mold. Therefore, in the case of manufacturing the next slab, if the stopper is opened and the molten copper is introduced into the mold, the oxygen-free copper becomes more likely to make direct contact with the oxygen of the outside atmosphere, which increases the oxygen dissolved amount of the oxygen-free copper, thereby degrading its quality. . Thus, in casting molten copper by semi-continuous casting device, even though each part of melting furnace, waterway, heat-reserving furnace, and tundish has structure to keep external air and airtight, Inevitably, it comes into contact with the outside atmosphere. In the whole process of semi-continuous casting process, there is a need to maintain the confidentiality with the outside in order to cast reproducible high quality oxygen-free copper during post-production.

The present invention relates to a mold of a semi-continuous casting apparatus, and in particular, in a semi-continuous casting process of anoxic copper, a mold part is provided with a gate and a gas curtain on the mold to effectively maintain airtightness with the external atmosphere through the entire process. An object of the present invention is to provide a casting apparatus for metal casting having a gate capable of casting excellent oxygen-free copper by preventing the inflow of impurity gas from the outside during opening and closing of the process to ensure reproducibility of the process.

1 is a partial cross-sectional view of a typical semi-continuous casting cooling mold

2a to 2d is a cross-sectional view of the working state in the semi-continuous casting device having a gate and a gas curtain according to the present invention.

<Description of Symbols for Major Parts of Drawings>

S: slab 103: molten metal inlet

100: mold 108: coolant tube

104: upper gate 105: lower gate

106: deoxidation gas inlet 107: base plate

200: tundish 201: nozzle

202: stopper L: molten metal

Hereinafter, a semi-continuous casting apparatus provided with a gate and a gas curtain for achieving the object of the present invention as described above will be described in detail with the accompanying drawings.

Figure 2 is a schematic cross-sectional view of a semi-continuous casting device having a gate and a gas curtain according to the present invention.

Semi-continuous casting device provided with a gate and a gas curtain according to the present invention is formed on the lower side of the tundish as shown in Figure 2 of the mold having a conventional structure so that the melt is introduced into the solidification ( 100 is formed, the mold 100 is usually of a predetermined length and a passage 102 through which liquid molten metal is introduced and solidified is formed therein, and the tundish is formed at an upper end of the mold 100. The nozzle 201 in which the stopper 202 of the 200 is formed and the molten metal inlet 103 into which the molten fish is introduced are formed, and the passage 102 is crossed across the body and the passage 102 of the mold 100. With a pair of plates to block or open Upper and lower gates 104 and 105 are formed, one of which is an upper gate 105 and one of which is a lower gate 105.

Although the upper gate 104 and the lower gate 105 are not shown in the accompanying drawings of the present specification, the gates 104 and 105 are configured to reciprocate left and right by a motor or a pneumatic cylinder so that the passage 102 It is configured to control the opening and closing of the molten metal in the mold (melt) and the slab to prevent the contact with the outside air. The relative distance, that is, the distance between the upper gate 104 and the lower gate 105, is preferably shorter than 300 mm longer than 100 mm. If the distance between the upper and lower gages 104 and 105 is shorter than 100 mm, cracks are generated in the slab during the secondary cooling (cooling by water). Is reduced.

A deoxidation gas inlet 106 is formed between the upper gate 104 and the lower gate 105 to penetrate the sidewall of the mold 100 and inject the reducing gas or the inert gas into the passage 102. The deoxidation gas inlet 106 is formed in solidarity with the spiral groove formed in the inner wall of the mold 100, and the spiral groove is formed from directly under the inner surface of the mold 100 in which the upper gate 104 is formed. It is formed in a spiral within a predetermined length of the inner surface of the lower mold 100 of the lower gate 105. The gas curtain in the passage 102 is maintained at 1.2 to 1.5 atm by injecting a reducing gas such as carbon monoxide, hydrogen, argon or nitrogen through the deoxidation gas inlet 106 to form a gas curtain. (In the accompanying drawings of the present specification, the illustration of the gas injection device is omitted.)

In addition, a bottom plate 10 7 configured to be movable up and down in the passage 102 of the mold 100 is formed, and a coolant pipe 108 through which coolant is circulated is formed in the body of the mold 100.

The operation of the semi-continuous casting device provided with a gate and a gas curtain according to the present invention having the above configuration will be described in detail with the accompanying drawings.

As shown in FIG. 2A, when molten copper in a molten state flows into the passage 102 of the mold 100 through the inlet 103 through the nozzle 201 of the tundish 200, the molten copper ( L) is accumulated on the bottom plate 107 in the passage 102 where it is lifted upward, and the introduced molten metal L is cooled by the cooling action of the cooling water pipe 108 to gradually solidify. The cooling water passing through the cooling water pipe 108 is set at about 0 ° C to 30 ° C so that the molten metal is solidified within a short time.

Before the molten metal (L) is injected into the passageway 102 of the mold 100, the molten metal injected by filling the reducing deoxidized gas or the inert gas through the deoxidized gas inlet 106 may be prevented from contacting with the external oxidizing air.

When the molten metal flows from the tundish 200 and reaches the predetermined amount, the stopper 202 of the tundish 200 blocks the nozzle 201 to the passage 110 of the mold 100 of the molten metal. This prevents the leakage of, by this time the base plate 107 in the mold 100 will be lowered by its own weight by a predetermined distance. The behavior at this time is shown in b of FIG.

However, as the introduced molten metal is cooled, cooling is first performed from the introduced molten metal so that solidification is achieved and the slab (S) is advanced.

When the slab S is further lowered in the mold 100 such that the upper end of the slab S passes through the upper gate 104 (see c of FIG. 2), the upper gate 104 is cast into the mold. Blocking the passage 102 across the passage 102 in the transverse direction of the (100) to block the upper space of the passage 102 and the space with the slab (S) of the slab (S) that solidification is in progress The upper side further blocks the contact with external air to prevent oxidation of the slab (S).

In order to prevent the solidification of the slab S in progress, the upper gate of the slab S passes through the lower gate 105 so that the lower gate 105 blocks the passage 102 in the same manner as the upper gate 104. (See d in FIG. 2), the lower gate 105 passes before the block 10 is closed, and the slab S passes through the deoxidation gas inlet 106 located below the lower gate 105. After the slab (S) having a predetermined length of external atmosphere is manufactured by injecting the above-mentioned reducing gas, that is, deoxidized gas (G), to maintain 1.2 to 1.5 atm of air pressure to the gas inlet 106 to prevent the introduction of external atmosphere. It is prevented from flowing into the passage 102 of the mold 100 to prevent the molten oxygen-free copper from contacting the oxygen of the outside atmosphere during the manufacture of the next slab (S) to be able to manufacture a high quality oxygen-free copper (See d in FIG. 2). As such, deoxidized gas (G) made of reducing gas or inert gas is filled in the upper side space of the molten metal which has not yet solidified, so that high-quality oxygen-free copper is produced.

Since the mold apparatus is sufficiently cooled by the coolant, the anoxic molten copper is already cooled within 30 cm from the upper end of the mold mold 100 and solidified in the shape of the slab (S), while lowering the bottom plate 109 of the mold apparatus. If the molten copper is continuously injected into the passageway 12 of the mold, a slab S having a length of 2-10 m is produced. At this time, in order to prevent sticking phenomenon in which the inner wall of the mold 100 and the oxygen-free copper solidified stick together, it is a general process of the mold to apply a weak vibration to the mold 100.

The casting device for metal casting with a gate and a gas curtain according to the present invention having the above-described constitution and operation has an external air and a process in which molten metal (melt) introduced into the mold from a tundish is cooled and slabed. The contact is completely blocked, so that there is no possibility of impurity mixing by external air, so that it is possible to cast oxygen-free copper of high quality. That is, the semi-continuous casting apparatus for maintaining the confidentiality with the outside atmosphere, especially when the semi-continuous casting of anoxic copper, can be effectively carried out by using the casting apparatus with the gate of the present invention to effectively maintain the confidentiality with the outside during semi-continuous casting. By suppressing the inflow of impurity gas from the outside into the mold apparatus, it is possible to ensure the smoothness of the casting operation and to maintain the reproducibility of the cast product.

Claims (3)

A semi-continuous casting apparatus for metal casting, comprising: an upper gate 104 and a lower gate 105 for covering a passage 102 of a mold 100; A degassing gas inlet 106 formed between the upper gate 104 and the lower gate 105 through the sidewall of the mold 100 and into which the reducing gas or the inert gas is injected into the passage 102; Semi-continuous casting device with gate and gas curtain formed between the upper gate 104 and the lower gate 105 is longer than 100mm and shorter than 300mm delete delete