JP4233140B2 - Tundish - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tundish used for continuous casting of a molten metal such as molten steel.
[0002]
[Prior art]
A continuous casting technique for continuously casting a molten metal such as molten steel is known. According to continuous casting technology, a container-shaped tundish that stores molten metal such as molten steel is used, and the tundish is placed above a water-cooled mold without a bottom, and the discharge hole at the bottom of the tundish is opened. The molten metal is discharged from the discharge hole, the molten metal is poured into a water-cooled mold to form a continuous metal piece, and the metal piece is pulled and conveyed by a pinch roll and cooled by a cooling spray zone.
[0003]
In continuous casting technology, the temperature of the molten metal stored in the tundish greatly affects the quality of the metal product. Therefore, a temperature measuring probe that can be immersed in the molten metal stored in the tundish is provided separately, and the temperature is measured while the temperature measuring probe is lifted by a crane.
[0004]
[Problems to be solved by the invention]
Since the temperature measuring probe described above is immersed in a high-temperature molten metal, high heat resistance is required. Therefore, a high heat-resistant structure such as multiple covering with a heat-resistant sleeve is required, and there is a tendency to increase in size and complexity.
[0005]
Unlike the above-described method, the present invention measures the temperature of the molten metal by utilizing the side portion of the dam wall that is a fire wall that partitions the storage chamber for storing the molten metal such as tundish molten steel. The task is to provide tundish.
[0006]
[Means for Solving the Problems]
The tundish of the present invention is disposed above the continuous casting apparatus, and has a refractory wall that divides a storage chamber for storing the molten metal, and a container shape having a discharge hole for discharging the molten metal stored in the storage chamber to the continuous casting apparatus. The fire wall is a weir wall that partitions the storage chamber into a plurality of chambers, and has a temperature measuring means for measuring the temperature of the molten metal, and the weir wall opens to communicate with the storage chamber has temperature measuring opening formed in one side surface of the weir wall so the distal end portion of the temperature measuring means measuring the temperature of the communication with the hot water storage chamber of the molten metal from the temperature measuring aperture opening into the reservoir chamber It is a feature.
[0007]
The temperature of the molten metal is measured by a temperature measuring means. In the present invention, a dam wall which is a part of the fireproof wall is used as the molten metal protective part of the temperature measuring means.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to the tundish of the present invention, the temperature measuring means can be generally configured using a thermocouple. The temperature measuring means may be mounted on a dam wall that is a fireproof wall during temperature measurement, or may be embedded in the fireproof wall integrally. The dam wall can be formed of an amorphous refractory formed by solidifying a castable refractory material having fluidity. In some cases, it may be formed of a regular refractory. The material of the fireproof wall is not particularly limited, and those conventionally used in tundish can be adopted. For example, alumina, zirconia, magnesia, chromium magnesia, chromium alumina, and the like can be adopted.
[0009]
According to a preferred embodiment, the side surface of the weir wall having the temperature measuring means has a temperature measuring opening communicating with the storage chamber, and the tip of the temperature measuring means is exposed at the temperature measuring opening and is made of molten steel or the like in the storage chamber. Can contact with molten metal. The temperature of the molten metal in the storage chamber can be measured by the temperature measuring means whose tip is exposed to the temperature measuring opening.
[0010]
Also, weir wall having a temperature measuring means, Ru weir wall der dividing the storage chamber into a plurality of chambers. It is preferable that the dam wall be of a system that can be detachably exchanged with the tundish. In general, the dam wall can be formed of a precast block that is cast and formed from a castable refractory material having fluidity and then dried and solidified.
[0011]
According to a preferred embodiment, the weir wall having the temperature measuring means has, in addition to the temperature measuring opening, an insertion passage whose one end communicates with the temperature measuring opening and an insertion opening which opens at the other end of the insertion passage. In this case, the temperature measuring means is detachably inserted into the insertion passage from the insertion opening.
[0012]
【Example】
(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS.
[0013]
An enlarged cross section of the tundish 1 of the present embodiment is shown in FIG. 1, and a plan view of the tundish 1 is shown in FIG. The tundish 1 is a large container disposed above the continuous casting apparatus, and has a steel wall 10 that forms an outer shell and a fire wall 12 that partitions a storage chamber 11 that stores high-temperature molten steel (1500 to 1650 ° C.). And a discharge hole 13 for discharging the molten steel stored in the storage chamber 11 to the continuous casting apparatus. The discharge hole 13 is opened and closed by a hydraulically driven sliding nozzle 1 c provided at the bottom of the tundish 1.
[0014]
The refractory wall 12 includes a lining wall 14 coated on the inner surface of the iron skin 10, and a dam wall 15 that is separate from the lining wall 14 and is detachably attached to the lining wall 14. The dam wall 15 is formed of an alumina-based precast block (alumina 60 to 70% by weight), and has a function of partitioning the storage chamber 11 into a plurality of chambers and removing non-metallic inclusions. The dam wall 15 has an upper surface portion 15b, a lower surface portion 15c, a side surface portion 15d, and a slope portion 15e provided with a hanging tool 15a. In the dam wall 15, the upper surface portion 15 b has a length of about 900 mm and a thickness of about 60 mm.
[0015]
A temperature measuring opening 20 (inner diameter: 60 mm) having a substantially circular shape communicating with the storage chamber 11 is formed in the side surface portion 15d of the dam wall 15. Further, an insertion passage 22 (inner diameter: 35 mm) that is a cavity having a circular cross section is formed inside the dam wall 15.
[0016]
One end of the insertion passage 22 communicates with the temperature measurement opening 20. A circular insertion opening 23 is formed at the other end of the insertion passage 22. The insertion opening 23 is formed in the upper surface portion 15 b of the dam wall 15.
[0017]
In the manufacture of the dam wall 15, a castable refractory material having fluidity is cast and molded in the mold with the core placed in the mold, and after drying and solidification, the frame is removed and the temperature is measured. 20, a precast block having an insertion passage 22 and an insertion opening 23 is formed.
[0018]
The temperature measuring probe 3 as a temperature measuring means is a separate body from the dam wall 15, and as shown in FIG. 3, a heat-resistant protective cylinder 30 and a hollow chamber 30 k of the protective cylinder 30 together with a holder 36. And an inserted thermocouple 32. The first conducting wire 32a and the second conducting wire 32c constituting the thermocouple 32 are coupled by a coupling portion 32d. The protective cylinder 30 includes a ceramic cylinder part 30r using Mo-ZrO ₂ as a base material and a metal cylinder part 30s using a stainless steel base material connected to the ceramic cylinder part 30r in a screw structure. When the temperature measuring probe 3 is detachably inserted from the insertion opening 23 of the weir wall 15, the distal end portion 3 w of the temperature measuring probe 3 is exposed from the temperature measuring opening 20 and contacts the molten steel in the storage chamber 11. Accordingly, the temperature measurement probe 3 can continuously measure the temperature of the molten steel in the storage chamber 11.
[0019]
When the continuous casting is completed, the temperature measuring probe 3 is removed from the insertion opening 23 of the weir wall 15. At the time of the next continuous casting, the temperature measuring probe 3 is inserted again from the insertion opening 23 of the weir wall 15 to measure the temperature of the molten steel in the storage chamber 11. Thus, when the temperature measuring probe 3 is inserted from the insertion opening 23 of the weir wall 15 and the temperature of the molten steel is measured at the time of temperature measurement, the weir wall 15 of the tundish 1 serves as a molten metal protection portion for the temperature measuring probe 3. A part of can be used. Therefore, it is advantageous in simplifying the molten metal structure and heat-resistant structure of the temperature measuring probe 3 and extending the life of the temperature measuring probe 3. Specifically, it is advantageous for simplification of the heat resistance function in the ceramic cylinder portion 30r based on expensive Mo—ZrO ₂ and simplification of the heat resistance function in the metal cylinder portion 30s based on stainless steel.
[0020]
(Second embodiment)
A second embodiment of the present invention is shown in FIG. This embodiment basically has the same configuration as that of the first embodiment, and the same portions are denoted by the same reference numerals. However, a buried cylinder 40 in the form of a refractory pipe penetrating in the length direction is buried in the weir body 15. The insertion passage 22 is defined by the inner wall surface 40t of the buried cylinder 40. The buried cylinder 40 is made of a material having better corrosion resistance and spalling resistance to molten steel than the material of the dam wall 15, specifically, zirconia as a base material. Further, if the buried tube 40 is formed of a material advantageous in strength, it is advantageous in securing strength in the vicinity of the insertion passage 22.
[0021]
(Third embodiment)
A third embodiment of the present invention is shown in FIGS. Also in this embodiment, the dam wall 15 is separate from the lining wall 14 of the tundish 1 and is detachably attached to the lining wall 14. The dam wall 15 is formed of a precast block (alumina 60 to 70% by weight) formed by casting a castable material. In the present embodiment, a bottomed buried cylinder 43 with the distal end portion 43 a closed is integrally buried in the dam wall 15. The distal end portion 43 a of the buried cylinder 43 is exposed from the temperature measurement opening 20 of the dam wall 15 and is in contact with the molten steel in the storage chamber 11. Since the distal end portion 43 a of the buried cylinder 43 is closed, the molten steel does not enter the inside 43 f of the buried cylinder 43. The buried cylinder 43 is composed of a ceramic cylinder part 43b using Mo—ZrO ₂ as a base material and a metal cylinder part 43c using stainless steel as a base material connected to the ceramic cylinder part 43b.
[0022]
In actual use, the thermocouple device 5 as a temperature measuring means is inserted into the interior 43 f of the embedded cylinder 43 embedded in the dam wall 15 to continuously measure the temperature of the molten steel in the storage chamber 11. At the time of temperature measurement, the tip portion 5w of the thermocouple device 5 is covered with the buried cylinder 43 and does not directly contact the molten steel. Therefore, it is advantageous for simplifying the molten steel structure and heat-resistant structure of the thermocouple device 5 and extending the life of the thermocouple device 5.
[0023]
In the present embodiment, the material of the embedded cylinder 43 is selected so that the lifetime of the embedded cylinder 43 is longer than the lifetime of the dam wall 15.
[0024]
If the dam wall 15 is damaged, the dam wall 15 is removed from the tundish 1 and disassembled. In this case, the buried cylinder 43 buried in the dam wall 15 is removed from the dam wall 15 and the buried cylinder 43 is used again when the new dam wall 15 is manufactured.
[0025]
Note the material of the ceramic tube portion 43b of the buried pipe 43 in place of the Mo-ZrO _2, aluminum nitride may be silicon nitride.
[0026]
In addition, the material of the buried cylinder 43 can be selected so that the life of the buried cylinder 43 buried in the dam wall 15 is terminated in accordance with the life of the dam wall 15. In this case, mullite and high alumina can be selected as the base material constituting the buried cylinder 43.
[0027]
(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIG. FIG. 7 shows a plan view of the weir wall 15. In the dam wall 15 of the present embodiment, the portion where the insertion passage 22 and the temperature measurement opening 20 are formed is a thick portion 15m. As a result, the strength in the vicinity of the insertion passage 22 can be increased. Furthermore, it is advantageous to further improve the resistance to molten steel protection against the temperature measuring means inserted into the insertion passage 22.
[0028]
(Application example)
An application example is shown in FIG. The continuous casting apparatus of this example includes a water-cooled mold 100 for forcibly cooling molten steel, a cooling spray band 101 for cooling a continuous cast piece with a cooling spray, a pinch roll 102 for pulling the continuous cast piece, and a straightening for bending the continuous cast piece. And a roll 103. The tundish 1 according to the present embodiment is disposed above the water-cooled mold 100. Then, with the ladle 106 for several tens of tons disposed above the tundish 1, the molten steel in the ladle 106 is supplied to the storage chamber 11 of the tundish 1 by the long nozzle 107 equipped at the bottom of the ladle 106. . Further, the molten steel in the storage chamber 11 of the tundish 1 is supplied to the water-cooled mold 100 from a sliding nozzle provided at the bottom of the tundish 1. The molten steel is cooled by the water-cooled mold 100 and solidifies from the outer shell to form a continuous cast piece W1, which is conveyed downward.
[0029]
【The invention's effect】
According to the tundish of the present invention, the temperature of the molten metal such as molten steel in the storage chamber can be measured by using the side surface portion of the dam wall that is a refractory wall that partitions the storage chamber for storing the molten metal such as molten steel.
[0030]
According to the tundish of the present invention, the side surface portion of the dam wall, which is a heat-resistant fire wall , can be used as the molten metal protection portion of the temperature measuring means, so the metal-resistant molten metal structure and the heat resistant structure in the temperature measuring means can be simplified. It is advantageous for extending the life of the temperature measuring means.
[Brief description of the drawings]
FIG. 1 is an enlarged cross-sectional view of a tundish having a dam wall.
FIG. 2 is a plan view of a tundish having a dam wall.
FIG. 3 is a cross-sectional view of a main part of a temperature measuring probe.
FIG. 4 is an enlarged cross-sectional view of a tundish having a dam wall according to another example.
FIG. 5 is a side view of a dam wall according to another example.
FIG. 6 is an enlarged view of the vicinity of a temperature measurement opening formed in a dam wall.
FIG. 7 is a plan view of a dam wall according to still another example.
FIG. 8 is a schematic view showing a state where a tundish is disposed above the continuous casting apparatus and continuous casting is performed.
[Explanation of symbols]
In the figure, 1 is a tundish, 11 is a storage chamber, 12 is a refractory wall, 13 is a discharge hole, 15 is a weir wall, 20 is a temperature measuring opening, 22 is an insertion passage, 23 is an insertion opening, and 3 is a temperature measuring probe. Indicates.

Claims (4)

A tundish that is disposed above the continuous casting apparatus and has a refractory wall that divides a storage chamber for storing molten metal and a discharge hole that discharges the molten metal stored in the storage chamber to the continuous casting apparatus. And
The fire wall is a weir wall that partitions the storage chamber into a plurality of chambers, and has a temperature measuring means for measuring the temperature of the molten metal,
The weir wall has a temperature measuring opening formed at one side surface of the weir wall so as to open to communicate with the storage chamber, and the tip of the temperature measuring means opens to communicate with the storage chamber. A tundish characterized in that the temperature of the molten metal in the hot water storage chamber is measured from the temperature measuring opening. 2. The tundish according to claim 1, wherein a tip end portion of the temperature measuring means is exposed at the temperature measuring opening and can contact the molten metal in the storage chamber. The weir wall having the temperature measuring means has an insertion passage whose one end communicates with the temperature measurement opening, and an insertion opening which is formed in the upper surface portion of the weir wall and opens at the other end of the insertion passage,
The tundish according to claim 1, wherein the temperature measuring means is detachably inserted into the insertion passage from the insertion opening. 4. The tundish according to claim 3, wherein a pipe-like buried cylinder made of refractory is buried in the dam wall, and the insertion passage is defined by the inner wall surface of the buried cylinder.

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