KR850001745Y1 - Tundish in a stell strip casting apparatus - Google Patents

Abstract

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Description

Tundish for metal strip casting equipment

1 is a side view showing a tundish of the present invention.

2 is a front view of the first degree tundish.

3 is a side view showing another tundish of the present invention.

Figure 4 is a side view showing another device of the present invention.

Figure 5 is a partial cross-sectional view of the tundish of the present invention showing the heating device of the plate forming a portion of the orifice passage.

FIG. 6 is a front view of the FIG. 5 tundish; FIG.

Figure 7 is a side view showing the fixing device of the present invention tundish.

8 is a plan view of the fixture and tundish shown in FIG.

9 is a cross-sectional view showing the base passage and the nozzle portion of the present invention tundish.

FIG. 10 is a plan view seen from the X-ray direction of FIG.

11 is a sectional view taken along the line XI-XI of FIG.

12 is a front view showing an orifice passage of the present invention.

13 to 17 is a side view showing a tundish of another form of the present invention.

The present invention relates to a new and improved apparatus for rapidly casting a metal strip, and more particularly to a tundish consisting of a number of vertical alignments and fixed blocks that are resistant to molten metal.

As strip casting methods are developed, it becomes clear that tundish design is important. Therefore, the assembly of the tundish is relatively simple, and in order to change the size of the orifice passage, the size of the inner passage, and the head height of the molten metal in the tundish, a suitable structure and material having flexibility are found.

Conventional strip casting methods such as US Pat. Nos. 905,758 and 993,904 have proven to be inflexible in tundish or receivers for molten metal. There is also no mention of tundish structures in the most recent literature, such as US Pat. No. 4,142,571 on vessels for receiving and pressurizing molten metal.

Thus, there is a need for a new and improved apparatus for casting metal strips with increased flexibility in prior art structures.

The present invention is a tundish having an internal passage for accommodating and retaining molten metal and a molten metal on a casting surface which is located within 0.120 inch from the orifice passage and is capable of moving through the orifice passage at a linear speed of 200-10,000 feet / minute It provides a continuous strip casting device for supplying. The tundish has at least one upper block and at least one lower block which are aligned and fixed vertically and resistant to the molten metal so as to sufficiently prevent the molten metal in the passage into the block interface. The orifice passage has a uniform width of at least 0.010 inches through its longitudinal length.

An advantage of the present invention is that it can be easily configured by stacking and fixing a block of resistance to molten metal having an internal passageway and a nozzle.

Typically the tundish for strip casting consists of blocks stacked horizontally. Significant erosion of molten metal occurs at the bottom of the tundish. The vertically stacked inventive design thus provides improved flexibility and structure. In particular, if the bottom part of the tundish of the present invention needs to be replaced, only the lower block can be removed and the upper block can be reused.

In addition to the ease of configuration and reuse in whole or in part, the present invention has the advantage of increasing or reducing the size of the inner passage by insertion and withdrawal of the intermediate block in the tundish.

The purpose of the present invention is to allow the deformation of the inner passage and orifice passage. In other words, the present invention provides a device including a tundish capable of maintaining a strict standard required for tundish of the main surface of the nozzle.

One advantage of the present invention is that the tundish material can utilize commercially available citina blocks at the lowest disposal rates without the need for complicated casting, cutting and other costly preliminary operations.

Another object of the present invention is to provide an improved strip casting apparatus in which at least one side forming the orifice passage of the tundish is heated before or after casting.

Referring to the present invention in more detail based on the accompanying drawings as follows.

1-4 illustrate various suitable devices of the present invention.

As shown in the figure, the device comprises a tundish 10 which has an inner passage 12 indicated by dashed lines in the first, third and fourth degrees. The inner passage 12 is designed to receive and retain the molten metal. The tundish 10 also includes an orifice passage 14 or nozzle that supplies molten metal in the passage to the casting surface 16 as described in FIG. In a suitable embodiment, the molten metal is fed through an orifice passage 14 on a water cooled casting surface 16 of precipitation hardened copper alloy including 99% copper. Various materials can be used to fabricate the casting surface 16, but copper and copper alloys are selected that have high thermal conductivity and good wear resistance.

In the present device, the casting surface 16 in the form of a circle or plane moves through the orifice passage at a linear speed of 200-10,000 feet / minute.

As shown, the tundish 10 has at least one upper block 20 and at least one lower block 30. The terms before and after as well as the upper and lower sides used in the present invention are used for the casting surface 16.

The upper and lower blocks 20 and 30 of the present invention tundish 10 are aligned and fixed vertically. As used herein, the term vertical alignment refers to the normal beta of all blocks forming a tundish when casting is carried out on an annular casting surface, and the casting is performed on a linear casting surface such as the plane of the casting belt and perpendicular to the axis of the casting wheel. The time means the transverse direction of the casting surface. When casting is carried out on the curved surface of the cast belt, the curved surface shall be the same as the annular cast surface. The normal vector is perpendicular to the plane of the block or sheet. The above relationship causes the tundish blocks to be vertically aligned with respect to the direction of gravity. This arrangement also causes the sheet normals of all blocks to be perpendicular to the longitudinal axis of the orifice passageway 14 so as to be perpendicular to the longitudinal axis of the orifice plate body 40, which, if used, also casts the strip. Perpendicular to the transverse direction. These representative arrangements have been described fully in the figures, but the term vertical alignment above requires a broader definition as the tundish may be arranged in various directions as shown in FIG. 17 at any position on the cast surface.

The vertically aligned blocks are fixed so that molten metal in the inner passage cannot enter the interface of the assembly. When the nozzle is located at the interface as shown in FIG. 2, the molten metal flows out through the nozzle, so the above-described interface does not include the portion forming the orifice passage 14.

Several intermediate blocks 22, 24 and 26 were disposed between the upper block 20 and the lower block 30. The vertical alignment of these blocks is an unrestricted passage for the molten metal which is supplied to the orifice passage 14 through the inner passage 12 from the opening to the orifice passage 14, which is formed in the tundish assembly. Should be sufficient to provide As shown in FIG. 16, the vertically stacked blocks need not be the same size but the blocks need not be perfectly aligned, and the inner passage 12 does not need to be perfectly aligned. In addition, as shown, the tundish 10 does not need to be configured only in a rectangular shape. In the tundish of the present invention, a block may also be used under the tundish for reasons of insulation stability.

The blocks used in the device of the present invention should be resistant to the erosion of molten metal. In this respect, a fireproof plate such as a heat insulating plate made of fibrous kaolin is suitable. Additional materials including graphite, alumina-graphite, clay-graphite, refractory clay, quartz, boron nitride, silicon nitride, silicon carbide, boron carbide, silica alumina, zirconia, stabilized zirconia silicate, magnesia, chromium magnesite and mixtures thereof It can be used for the production of road blocks.

In a suitable embodiment the tundish is constructed by vertically stacking 1.5 inch thick "Kaolwool" fiberboard. The surface of kaolin exposed to molten metal is impregnated with silica gel. Thicker or thinner blocks are used depending on the desired strip casting conditions, and because of their commercial availability, in a suitable embodiment a 1.5 inch thick block was used. As described above, the commercial availability of block materials is a significant advantage of the present invention, and fibrillated kaolin blocks are more suitable because they are inexpensive and easy to drill and bend into the desired final shape. However, other materials may be used in the same manner, and may be cast in a desired structure instead of curved as needed.

The tundish 10 of the present invention includes an inner passage 12 composed of at least one introduction passage 32 and the introduction passage 32 extends from the upper block 20 through the intermediate block and the lower block 30. In the lower portion of the tundish 10 formed in the inside is connected to the base passage 34 formed in the air. The opening to the introduction passage 32 is located in the upper surface of the upper block 20 as shown in FIGS. 1, 3 and 4, but this opening is everywhere as described in FIG. It may be located. In addition, as shown in FIG. 5, the opening is slightly curved in the form of a funnel to thereby supply molten metal.

In the device of the present invention, the shape of the base passage 34 and the orifice passage 14 is arbitrary. Typically, the base passage 34 is formed between the bottom portion 36 and the curved surface 38 of the block adjacent to the lower block by recessing or casting in the lower block 30. In addition, as shown in FIG. 4, the base passage 34 may be formed in the interposed intermediate block 26, and the curved surface 38 of the base passage 34 is part of the upper surface of the lower block 30. Can be formed. Even in the latter case, part of the upper surface of the lower block can be removed for the following reasons.

Although not necessarily, most of the curved surface 38 of the base passage 34 is disposed below the height of the orifice passage 14, which explains that this structure is not essential. However, in one embodiment, a portion of the bottom portion of the base passage 34 is located 0.125 inches below the orifice passage 14. Furthermore, the curved surface 38 of the base passage 34 extends toward the nozzle at an angle of at least 20 °, in particular 30 °, from the horizontal as described in FIG. Molten metal approaching the orifice passage below 20 ° tends to condense in the nozzle due to lack of heating, which impedes casting operations.

The orifice passage 14 through which the molten metal is supplied onto the casting surface 16 has a uniform width throughout its longitudinal length, which width is preferably at least 0.010 inches, in particular 0.120 inches or less. The uniform width for the orifice passage 14 is suitably in the range 0.020-0.060 inches, particularly in the range 0.030-0.050 inches.

Orifice passage 14 may be configured in the device of the present invention in a number of ways. In the embodiment described in FIGS. 1 and 2, an orifice passage 14 is formed between the bottom portion 36 of the block 20 and the upper surface of the lower block 30 adjacent to the lower block 30. The orifice passage 14 is formed by removing a portion of one aligned block at the interface. In addition, the orifice passage may be made by cutting a portion of the front wall adjacent to the lower block or by combining the cut portions of the lower block 30. Regardless of how the orifice passage is constructed, the strict dimensions mentioned above must be maintained.

At least one surface forming the orifice passage in a suitable embodiment as described in FIGS. 5, 6 and 9 consists of a plate 40 disposed in one block. As shown, the upper surface, that is, the surface downstream of the casting direction of the orifice passage 14 is preferably composed of a plate 40 made of a material resistant to molten metal. It is more arbitrary to maintain the top surface of the orifice passage during casting, and it is preferable to use a high strength plate in this position. The bottom portion may be composed of a plate 41 as shown in FIG. 15, or both sides of the orifice passage may be composed of plates 40 and 41 as shown in FIG. These plates 40 and 41 as well as the tundish assembly must have structural stability and corrosion resistance as well as resistance to molten metal as compared to the rest of the tundish 10. Such plates should often be more resistant than the blocks that form the rest of the tundish. As shown in FIG. 6, the plate 40 is inserted into a suitable recess formed in the bottom surface of the intermediate block 24, or is formed in a set with vertically stacked tundish blocks and the peripheral edge of the plate 40 is " Covered with a suitable insulator, such as " Fiberfrax ", to insulate and seal the edge of the plate 40. The plate 40 should have a length longer than the longitudinal length of the orifice passage 14, whereby the peripheral edge of the plate 40 is sandwiched between adjacent blocks 24 and 30 in the tundish of the present invention. It became.

In a suitable embodiment the plate 40 is made of boron nitride or refractory clay, silicon nitride, silicon carbide, boron carbide, silica, alumina, zirconia, stabilized zirconia silicate, graphite, alumina-graphite, clay-graphite, quartz, magnesia Other materials, such as, coromagnesite and mixtures thereof, may be used in the manufacture of the plate 40.

As described above, the introduction passage 32 of the tundish 10 is connected to the base passage 34. In a suitable embodiment the introduction passage 32 consists of a tubular passage through a plurality of vertically stacked blocks. The number of blocks used or the total height of the tubular passages provides the passage heights for adjustment and allows the desired head of molten metal to be used in the tundish. The casting pressure is directly related to the head height of the molten metal, and the range of head height can be easily obtained by increasing and decreasing the intermediate block. In addition, the intermediate block and the upper block 20 can be reused through a plurality of casting processes.

An apparatus for heating the plate 40 forming the top wall of the orifice passage as described in FIGS. 5 and 6 may be provided. In a suitable embodiment at least one lance 42 having a tip 44 facing the outer surface of the plate 40 with respect to the orifice passage 14 is disposed in the tundish. Also shown in FIG. 5, a discharge passage 46 is provided in the tundish such that the combustion product supplied to the plate 40 is discharged from the tundish. The number of lances depends on the width of the strip to be cast from the tundish. The temperature of the plate 40 can be raised to the desired height before the start of strip casting. The heating of the plate 40 to the melting temperature of the alloy to be cast is to prevent solidification in the inner passage where metal may occur at the beginning of casting. In a suitable embodiment the hot acetylene salt is directed from the lance to the plate. In order to reduce unwanted flame influences on the plate 40, a flame-resistant thermal conductive layer 48 may be installed on the outer surface of the plate 40 at the location where the flames strike the plate 40. 48 absorbs flames and effectively transfers heat to the lower plate 40. In a suitable embodiment this layer may be used with other materials but graphite is suitable.

As described above, in the present invention, it is necessary to fix the vertically aligned blocks forming the tundish. In the preferred embodiment shown in FIGS. 7 and 8, the blocks forming the tundish are formed by four upright spiral rods 51, 52, 53, 54 and two stators 56, 58. It is fixed on the support table 50. As shown in FIG. 7, the intermediate fixture 58 affects the force required for most downtight and positioning in a suitable fastening system, which is secured with a spring 60 to preheat and strip. The contraction in the block due to mechanical degradation caused by the hot molten metal flowing during casting is maintained such that the force continuously acting down on the stacked tundish blocks is arranged vertically as small as possible. The spring-loaded backside fixture 56 provides the necessary pressure to prevent the stacked blocks from tilting towards the casting surface 16 due to shrinkage and continuous pressure, and also to allow the discharge plug 62 to be inserted without leakage as described in detail later. To provide. In addition to the mechanical coupling of the tundish assembly, the tundish is also fastened using screws, coupling devices, adhesives, cements such as alumina-silica cement, and other devices or methods that prevent metals from flowing into the tundish block. Can be.

A discharge stopper 62 is provided on the underside of the tundish as shown in FIGS. 5 and 7. This plug is not essential, but is preferably located below the orifice passage 14. The purpose of this discharge plug 62 is to quickly stop the molten metal supplied from the orifice passage 14 when the casting process is to be stopped for some reason. It is very important to stop the casting process as soon as possible when a decision is made to stop casting. At the end of the casting process, an inconsistent and intermittent flow of molten metal will flow through the orifice passage 14 which will hit the rapidly moving casting surface without the necessary adjustments for commercially acceptable strip production. At the end of the casting process, uncontrolled molten metal that falls through the nozzles splashes onto successful castings, ruining the strip and causing damage to the strip casting machine. In addition, in order to reuse the tundish, it is important to discharge from the tundish 10 before solidification of the molten metal in the inner passage 12 at the end of the casting process. Therefore, by removing the stopper 62, all the molten metal in the tundish can be exported through the stopper to a suitable container for receiving the molten metal. When a problem occurs during the casting process, the stopper 62 may be pulled out to minimize damage to the strip or casting apparatus.

9, 10 and 11 illustrate a suitable base passage of the present invention. The geometry of the casting passage is of great importance for the final quality of the metal strip produced thereby, especially when the width of the casting strip increases. Any geometrically reasonable design in the design of the casting passage under given conditions such as melting temperature, head height of molten metal, degree of orifice opening, temperature of plate 40, casting surface speed and distance from orifice to casting surface Failure to use the form will result in a significant change in quality over the full width of the wider metal strip. Their features include two special factors: the slope and the cross-sectional shape of the passageway. In a suitable embodiment as described in FIG. 9, the bottom portion 38 of the base passage 34 extends upwardly toward the orifice passage 14 at an angle of at least 20 degrees, in particular 30 degrees, from the horizontal.

In another suitable embodiment as described in FIG. 11, a part of the cross-sectional shape of the bottom portion 38 of the base passage 34 has a plate shape or a concave lens shape. In particular, the height hc of the base passage in the center should be at least 0.10 inch greater than the height h of the base passage 34 as measured at both sides of the base passage 34.

As shown in the preferred embodiment shown in FIG. 10, the introduction passage 32 can be laid to a suitable size through vertically stacked blocks of a material resistant to molten metal. The lower block 30 as shown in FIG. 10 is properly cut into a fan-shaped structure extending outward. In particular, the base passage 34 extends outwardly from the bottom of the introduction passage 32 toward the final orifice passage in the direction of the orifice passage 14 and its length is approximately equal to the width of the strip to be cast. In addition, a plurality of holes may be drilled in vertically aligned blocks to form the introduction passage 32 depending on the width of the strip material to be cast.

As described above, the orifice passage 14 should have a uniform width W throughout its longitudinal length. As shown in FIG. 12, the pole W can make some changes in the sides without affecting uniformity. In particular, the edge portion of the metal strip produced by the device of the present invention can be improved by expanding the side portion of the orifice passage (14). The height H of the enlarged side portion should be less than 1.5 times the uniform width W of the orifice passage 14. In addition, the length of the side portions of the enlarged orifice passage 14 should not exceed at least three times the uniform width of the orifice passage 14, and in particular two times or less is appropriate. As shown in FIG. 12, the extension structure embodied extends downwardly but may extend upwardly or bilaterally. This expansion structure is intended to allow a larger amount of molten metal to be supplied at these side portions than at the inner portion of the orifice 14. In addition, the height H of the extension portion must be continuously increased in the direction of both sides of the orifice passage 14, and this height H should not be reduced in the direction of both sides.

Claims (1)

A tundish 10 for metal strip casting apparatus supplied with molten metal to the casting surface 16 which is at a distance of 0.120 inches from the orifice passage 14 and travels at a linear speed of 200-10,000 feet / minute. In this case, the tundish 10 is fibrinated kaolin, graphite, alumina graphite, clay graphite, refractory clay, quartz, boron nitride, silicon nitride, silicon carbide, boron carbide, silica, alumina, At least one upper block 20 selected from zirconia, stabilized zirconia silicate, magnesia, corommagnesite and mixtures thereof, and at least one lower block 30 which is vertically aligned to this and fixed so that molten metal does not penetrate the interface. A tundish configured for a metal strip casting apparatus, wherein the orifice passageway 14 is configured to have a width of at least 0.010 inches through its longitudinal length.