KR200217173Y1 - 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 semi-continuous casting, during work, and completion of 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 the gate and gas curtain of the present invention has a passage through which the Kate 104 and 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. Meanwhile, in order to prevent impurities from outside air from flowing into the mold apparatus in addition to the gates 104 and 105, a deoxidation gas inlet groove 106 is provided between the mold apparatuses in which the gates 104 and 105 are located. It is characterized by.

The present invention is equipped with a gate that can be blocked from the outside atmosphere in the mold to effectively maintain the airtight with the outside atmosphere during semi-continuous casting, in particular the semi-continuous casting process of anoxic copper, during the opening and closing of the mold part 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 semi-continuous casting, during work, and completion of 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, since the airtightness of the casting apparatus must be continuously maintained between all processes during operation for the next operation from impurity gases such as oxygen and moisture in the external atmosphere, the conventional cooling mold apparatus There is a problem that is not suitable in the semi-continuous casting of the oxygen-free copper.

Oxygen-free copper (OFC) generally 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 less than 4ppm, and according to C-102 and C-1020 standard of other countries, oxygen dissolved amount in copper is less than 10ppm. 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 the semi-continuous casting process of anoxic copper, a mold part is provided with a gate and a gas curtain in the mold to effectively maintain the 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 the reference numerals for the main parts of the drawings>

S: slab 103: molten metal inlet

100: mold 108: coolant tube

104: upper gate 105: lower gate

106: deoxidation gas inlet groove 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. A pair of plated gates 104 and 105 are formed that block or open, one is the top gate 105 and one is the bottom 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.

In addition, a deoxidation gas inlet groove 106, which is a spiral groove, is formed on an inner side surface of the mold frame 100 constituting the passageway 102. It is formed spirally within a predetermined length of the inner surface of the lower mold 100 of the lower gate 105 from immediately below the inner surface of the formed mold 100. In addition, the degassing gas inlet groove 106 is injected with a reducing gas such as carbon monoxide, hydrogen, argon or nitrogen to maintain the gas pressure in the passage 102 so as to maintain 1.2 to 1.5 atm. (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 frame 100, the molten metal injected by filling the reducing deoxidizing gas or the inert gas through the deoxidizing gas inlet groove 106 is 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 102 of the mold 100 of the molten metal. Outflow is prevented, and at this time, the base plate 107 in the mold frame 100 is 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 through the deoxidation gas inlet 106 located at the lower side of the lower gate 105 before the lower gate 105 occludes the passage 110. After the slab (S) having a predetermined length of external atmosphere is manufactured by injecting the above-mentioned reducing gas, that is, the degassing gas (G), to maintain 1.2 to 1.5 atm of air pressure in the groove (106). It prevents the inflow into the passage 102 of the 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 enable the final production of 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 passage 10 2 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.

In other words, if the mold apparatus with the gate of the present invention is used, the semi-continuous casting apparatus that maintains the confidentiality with the external atmosphere can be effectively performed during semi-continuous casting, especially during semi-continuous casting of anoxic copper. 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)

In the semi-continuous casting device for metal casting, an upper gate 104 and a lower gate 105 covering the passage 102 of the mold 100 are provided, and a reducing gas or a groove is formed in the inner wall of the mold 100. Semi-continuous casting device provided with a gate and a gas curtain formed with a deoxidation gas inlet groove 106 into which an inert gas is injected The degassing gas inlet 106 is formed in a recess on the inner wall of the mold 100, and a predetermined distance between the lower side of the upper gate 104 and the lower side of the lower gate 105. Semi-continuous casting device with gate and gas curtain formed in According to claim 1, after the injection of the molten metal in the passage 102 of the mold 100 is completed, the solidification of the molten slag proceeds as the upper end of the slab (S) passes through the upper gate 104 and lower gate 105 After passing through each of the gates 104 and 105, the passages are sequentially blocked, and immediately before the lower gate 105 closes the passage 102, the deoxidizing gas inlet 106 is formed of a reducing gas or an inert gas. Semi-continuous casting apparatus provided with a gate and a gas curtain filled with G) is filled in the space of the upper passageway 102 of the upper end of the slab (S) that is not solidified.