JP2003065858A - Dipping cylindrical body for molten bath and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dipping cylindrical body for a molten bath and its manufacturing method capable of suppressing generation of a crack or fracture of a protective sleeve or a gap between the protective sleeve and a cermet protecting tube to be generated when dipped into the molten bath, by reducing the difference of a thermal expansion coefficient between the protective sleeve and the cermet protecting tube. SOLUTION: In this dipping cylindrical body 10 for the molten bath wherein the protective sleeve 15 comprising a refractory material is provided on the circumference of the cermet protecting tube 13 to be dipped into the molten bath 14, the protective sleeve 15 comprises a molded component of a carbon- including refractory. This manufacturing method has a process for pressure- molding a molding material 48 comprising the carbon-including refractory on the circumference of the cermet protecting tube 13, and a process for forming the protective sleeve 15 by calcining the pressure-molded molding material 48, and thereby the protective sleeve 15 integrated with the cermet protecting tube 13 is molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cermet protective tube for protecting an internal protective tube for holding a thermocouple for measuring the temperature of molten metal such as hot metal and molten steel and a dip tube body for blowing an additive into the molten metal. The present invention relates to a molten metal immersion cylinder and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, an internal protective tube for holding a thermocouple for measuring the temperature of molten metal such as steel is provided in a cermet protective tube having high corrosion resistance to the molten metal, and a temperature measuring probe for molten metal is provided. (Example of molten metal immersion cylinder) is formed.
Further, an immersion pipe (another example of the immersion cylinder for the molten metal) for blowing an additive (including air and an inert gas) into the molten metal is formed inside the cermet protection pipe whose tip is open. However, the cermet protection tube is a mixture of ceramic powder and refractory metal powder, pressure-molded, and sintered.Since it has low resistance to oxidation by slag and air formed near the surface of the molten metal, cermet protection tube For example, alumina carbonaceous material, zirconia carbonaceous material, or magnesia carbon, which has slag erosion resistance to the molten metal, is disclosed on the outer periphery of the portion of the protective tube that is immersed in the molten metal, as disclosed in, for example, JP-A-10-197353. A protective sleeve of refractory material made of carbon-containing refractory such as quality is provided to give durability to the cermet protection tube. The protective sleeve is formed in advance so as to be fitted to the outside of the cermet protective tube with a gap, and the cylindrical gap between the cermet protective tube and protective sleeve is made of, for example, alumina, magnesia, etc. Cement (aluminum, magnesia, zirconia, or other carbon-free or low-carbon) is filled with a filler which is powdered or mixed with a binder to be a liquid, and the cermet protective tube and the protective sleeve are integrally joined.

[0003]

However, the above conventional methods have the following problems to be solved. (1) There is a difference in the coefficient of thermal expansion between the cermet protective tube and the refractory cement, and between the refractory cement and the protective sleeve made of the carbon-containing refractory, and when the molten metal immersion cylinder is immersed in the molten metal. Due to thermal shock, there may be cracks or breaks in places that are disadvantageous in terms of strength, especially in the outermost protective sleeve,
The gap between the cermet protection tube and the protection sleeve sometimes expanded. (2) Further, cracks or cracks are generated at the immersion position of the protective sleeve, so that the protective sleeve is broken or the cermet protective tube is corroded or oxidized from the crack or the crack itself or the portion where the molten metal is eroded from the crack or the crack. Occurred, the strength of the temperature-measuring probe for molten metal and the immersion pipe decreased, and the life was shortened.
In particular, if slag formed near the surface of the molten metal enters the cracks in the protective sleeve or the gap between the cermet protective tube and the protective sleeve, the slag will cause strong erosion and oxidation. The strength of the inside of the protective sleeve was more severe than that of the tip of the tube, and the life of the portion provided with the protective sleeve was sometimes shorter than that of the tip.

(3) As a countermeasure against cracks or cracks in the protective sleeve, even if the end of the gap is coated with fireproof cement to seal the gap, the thermal expansion of the cermet protective tube, the fireproof cement and the protective sleeve. Since the difference in the rate cannot be reduced, the effectiveness of the coated refractory material in the process of being immersed in the molten metal decreases, and it is not possible to sufficiently prevent the occurrence of cracks, cracks, expansion of gaps, and the like. The present invention has been made in view of such circumstances, and a molten metal immersion cylinder capable of suppressing cracks and cracks in the protective sleeve, and generation of a gap between the protective sleeve and the cermet protection tube when immersed in the molten metal. It is an object to provide a manufacturing method thereof.

[0005]

According to a first aspect of the present invention, there is provided a molten metal immersion cylinder having a protective sleeve made of a refractory material on the outer periphery of a cermet protection tube immersed in the molten metal. In the body, the protective sleeve is formed of a carbon-containing refractory molded body, and is integral with the cermet protective tube. As a result, the protective sleeve can contain a large amount of carbon, for example, about 5 to 50%, so that the surface of the protective sleeve is not oxidized while being immersed in the molten metal unless it is exposed to an atmosphere in which oxygen is present. The traveling speed is extremely slow, and the reduction in strength due to embrittlement can be suppressed. Furthermore, since the thermal expansion coefficient of the protective sleeve is lower than that of the cermet protective tube, the cermet protective tube is pressed by the difference in thermal expansion coefficient when the molten metal immersion cylinder is immersed in the molten metal, and the cermet protective tube and protective sleeve are The gap between them is tightened, and the generation of the gap that occurs in the conventionally used refractory cement is suppressed, and the infiltration of molten metal or slag is prevented. This effect is repeatedly obtained every immersion operation, and even if the effect declines during use, the service life can be maintained until the melting life due to erosion of the exposed part of the tip of the cermet protection tube, and conventional fire resistance It is possible to obtain a molten metal immersion cylinder having a longer life than cement.

The molten metal immersion cylinder according to the second aspect of the present invention is a molten metal immersion cylinder in which a protective sleeve made of a refractory material is provided on the outer periphery of a cermet protection tube immersed in the molten metal. The sleeve is made of a molded product of carbon-containing refractory and is integrally joined to the cermet protective tube via a filler made of carbon-containing refractory. This allows
Since the filler and protective sleeve are made of carbon-containing refractory material having substantially the same coefficient of thermal expansion, cracks or cracks may occur in the filler and protective sleeve even when immersed in high-temperature molten metal,
It is possible to prevent the gap between the cermet protection tube and the protection sleeve from expanding. Further, since it is a construction in which the cermet protective tube and the protective sleeve that has been formed and fired in advance are joined with a filler made of the same material as the protective sleeve, in the case of carbon-containing refractory powder, for example, 100 to 3
When liquefied at around 00 ° C using an alcohol-based binder for the powder, cushioning properties can be provided by making the density after drying at around 70-300 ° C lower than that of the protective sleeve. The stress due to the difference in thermal expansion between the protective sleeve and the protective sleeve is reduced.

According to a third aspect of the present invention, there is provided a method of manufacturing a molten metal immersion cylinder, wherein a protective sleeve made of a refractory material is provided on the outer periphery of a cermet protective tube to be immersed in the molten metal, and a thermocouple having a sealed tip is provided. A method for manufacturing a molten metal immersion cylinder applicable to an internal protection tube, or an immersion tube main body in which an end is open and an additive is blown into the molten metal, wherein a molding material made of a carbon-containing refractory is formed on the outer periphery of the cermet protection tube. A step of pressure molding,
And a step of forming a protective sleeve by firing the pressure-molded molding material, and molding the protective sleeve integrated with the cermet protective tube. As a result, the protective sleeve has, for example, a cermet protection tube arranged in the center of a hydraulic forming die having a cylindrical recess, and a carbon-containing fireproof material in the cylindrical gap between the cermet protection tube and the inner wall of the recess surrounding the outer periphery of the cermet protection tube. Thing (for example,
A molding material composed of a mixture containing 85 wt% of powdery alumina and 13 wt% of graphite and a binder such as a phenolic resin added thereto is charged and pressure-molded by a hydraulic molding device. Therefore, the cermet protective tube and the protective sleeve enhance the adhesion of the contact surfaces with each other, prevent the infiltration of molten metal or slag from between the cermet protective tube and the protective sleeve, and the brittleness of the cermet protective tube due to oxidation, and the life The decrease can be suppressed. Since the length of the cermet protective tube is 10 to 50 times the diameter, when the protective sleeve provided along the longitudinal direction is molded, if the molding material is compressed and pressed in the longitudinal direction, the density in the longitudinal direction is increased. Variation may increase and the quality may deteriorate. However, when pressure molding is performed with a hydraulic molding device, pressure can be applied in the direction perpendicular to the longitudinal direction of the protective sleeve, so uniform pressure can be applied over the entire length, and a protective sleeve with uniform density can be applied. Obtainable.

In the method of manufacturing a molten metal immersion cylinder according to the third aspect of the present invention, the protective sleeve may be formed with the heat insulating buffer layer provided on the outer periphery of the cermet protective tube. In this case, between the cermet protective tube and the protective sleeve, a heat insulating buffer layer made of an aggregate bonded by, for example, a hydrolyzate of a metal alkoxide is formed. At this time, since the heat insulating buffer layer is formed in a sheet shape having a high porosity that does not reach a sintered state during the sintering operation of the protective sleeve, it provides cushioning between the cermet protective tube and the protective sleeve, The effect of absorbing the expansion force of the cermet protection tube can be obtained, cracks and cracks of the protection sleeve can be prevented, and oxidation of the inside of the protection sleeve and the surface of the cermet protection tube can be further suppressed.

According to a fourth aspect of the present invention, there is provided a method for producing a molten metal immersion cylinder, wherein a protective sleeve made of a refractory material is provided on the outer periphery of a cermet protective tube to be immersed in the molten metal, and the tip of the thermocouple is sealed. A method for producing a molten metal immersion cylinder applicable to an internal protection tube, or an immersion tube main body for blowing an additive into a molten metal with an open tip, wherein a protective sleeve made of a carbon-containing refractory material is provided on the outside of the cermet protection tube. Arranging, filling the tubular gap between the cermet protective tube and the protective sleeve with a filler made of carbon-containing refractory, forming a protective sleeve integrated with the cermet protective tube, and the protective sleeve, And a step of firing. As a result, a protective sleeve made of carbon-containing refractory can be formed in advance, and the cylindrical gap between the protective sleeve and the cermet protective tube is filled with a filler to bond the cermet protective tube and protective sleeve. To do. Therefore, by using a refractory material made of the same carbon-containing refractory material as the protective sleeve, the filler material and the protective sleeve can easily adhere to each other, and when filling, for example, the refractory material is vibrated by a vibrator to increase the density. By adjusting, the effect of giving cushioning property and absorbing the expansion force of the cermet protection tube can be obtained. Furthermore, the stress due to thermal expansion and thermal shock generated in the protective sleeve, the filler and the cermet protective tube when immersed in the molten metal can be relieved. Further, the protective sleeve can be formed into a uniform density over the entire length by the hydraulic forming device, and the quality of the protective sleeve can be maintained high.

In the method for manufacturing a molten metal immersion cylinder according to the fourth aspect of the present invention, the filler may be in the form of powder, liquid containing powder, or clay. In this case, when the filler is in a powder form, it is possible to shorten the time for drying after filling the cylindrical gap between the cermet protective tube and the protective sleeve. Further, when the filling material is in a liquid state, it suffices to flow the filling material into the cylindrical gap, which simplifies the automation of the work. Furthermore, when the filler is clay-like, it can be formed with high dimensional accuracy without protruding from the cylindrical gap when being pushed into the cylindrical gap, and the drying time and the filling operation time can be shortened. In the method for manufacturing a molten metal immersion cylinder according to a fourth aspect, a viscous sealing material formed by kneading a powder made of a carbon-containing refractory and a binder is press-fitted into at least one end side of the cylindrical gap. You may have the process of doing. In this case, after the filler is charged into the tubular gap, it does not stick out or leak out from the tubular gap in the drying process, and the quality of the molten metal immersion tubular body is stabilized.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a sectional view of a molten metal immersion cylinder according to a first embodiment of the present invention, FIG. 2 is a sectional view of a hydraulic forming apparatus used in a method for manufacturing the molten metal immersion cylinder, and FIG. A) and (B) are explanatory views of a method for manufacturing the same molten metal immersion cylinder, FIG. 4 is a cross-sectional view of a modified example of the same molten metal immersion cylinder, and FIG. 5 is a second embodiment of the present invention. 6A, 6B, and 6C are explanatory views of a method for manufacturing the molten metal immersion cylinder, and FIG. 7 is a method for manufacturing the molten metal immersion cylinder. FIG. 3 is a cross-sectional view of a hydraulic forming device used for

As shown in FIG. 1, the molten metal immersion cylinder 10 according to the first embodiment of the present invention has a sealed end.
For example, a thermocouple 11 made of platinum-platinum rhodium is enclosed in an insulated state, and an internal protective tube 1
2 and a cermet protection tube 13 charged therein.
Further, when the cermet protection tube 13 is immersed in the molten metal 14 from the tip, the molten metal 1 is attached to the outer periphery of the cermet protection tube 13.
4, a protective sleeve 15 made of a molded product of a carbon-containing refractory material is provided. In addition, since the slag 16 having strong oxidizing property is generally formed near the surface of the molten metal 14, the protective sleeve 15 can suppress the oxidation of the cermet protective tube 13 by the slag 16. A terminal box 18 having a connection terminal 17 for the thermocouple 11 is attached to the upper portion of the cermet protection tube 13.

Here, a method of manufacturing the molten metal immersion cylinder 10 according to the first embodiment will be described with reference to FIGS.
A description will be given based on (B). In addition, as a manufacturing facility, a hydraulic molding die 20 and a hydraulic molding device (CIP: c) for forming a protective sleeve 15 on the outer circumference of the cermet protective tube 13 in advance.
old isostatic pressing) 21
To prepare. This hydraulic molding die 20 has a steel pedestal portion 23 having a cylindrical protrusion 22 having an outer diameter substantially the same as that of the protective sleeve 15 in a portion excluding the peripheral portion. At the center of the pedestal portion 23, a concentric circle with the protrusion portion 22,
A lower holding hole 24 having an inner diameter into which the cermet protection tube 13 can be inserted and having a depth corresponding to at least the length from the tip of the cermet protection tube 13 to the position where the protection sleeve 15 of the cermet protection tube 13 is provided. It is provided so that the cermet protection tube 13 can be positioned. The protruding portion 22 has an inner diameter that a part of the protruding portion 22 fits in without a gap in the outer diameter, and has a cylindrical shape made of an elastic member such as urethane rubber, for example, 20% of the length of the cermet protection tube 13. A relatively long outer frame 26 is fitted. Then, a cylindrical recess surrounded by the upper surfaces of the outer frame 26 and the protrusion 22 is formed inside the outer frame 26, and when the cermet protection tube 13 is inserted into the lower holding hole 24, the cermet protection tube A cylindrical gap 27 is formed between 13 and the inside of the outer frame 26.

On the upper side of the outer frame 26, the outer diameter can be fitted inside the outer frame 26, and the inner diameter is such that the cermet protection tube 13 can be inserted on the same axis as the axis of the lower holding hole 24. A length adjusting middle frame 25 for adjusting the length of the protective sleeve 15 is provided. In addition, above the outer frame 26, a rubber lid 30 is provided, which has a pressing portion 29, the outer diameter of which can be fitted inside the outer frame 26, and which projects downward. A sealing member (for example, vinyl tape) 28 is attached to the boundary between the pedestal portion 23 and the lid portion 30 and the outer frame 26, and the pedestal portion 23, the outer frame 26, and the lid portion 30 are integrated. As a result, the hydraulic mold 20 is formed so as to seal the inside.
The hydraulic forming device 21 has a hydraulic tank main body 38 having an opening 37 provided above which the hydraulic forming die 20 can be loaded, and a tank lid 39 for sealing the opening 37. A drainage port 41 having a drainage valve 40 and a water supply port 43 having a water supply valve 42 are provided at the lower end portion of the water pressure tank body 38, and a supply / exhaust port 45 having an air supply / exhaust valve 44 is provided at the tank lid 39. It is provided. The water supply valve 42 has 0.5
Water supply pump 46 that generates a pressure of about ² kg / cm ²
Is provided.

After the hydraulic forming die 20 and the hydraulic forming apparatus 21 are prepared, the next step is carried out. (1) First, the protective sleeve 15 of the cermet protective tube 13
The aggregate formed by the hydrolyzate of the metal alkoxide is applied to the position where the metal is formed with a buffer made into a liquid state by a binder such as polyvinyl alcohol (PVA) and dried to have a thickness of 0.5 to A heat insulating buffer layer 47 having a thickness of about 1.0 mm is provided. (2) As shown in FIG. 3 (A), the tip of the cermet protection tube 13 provided with the heat insulating buffer layer 47 is inserted downward into the lower holding hole 24. Next, the outer frame 26 is attached to the pedestal portion 23, and the sealing member 28 is attached to the boundary portion between the outer frame 26 and the pedestal portion 23.
Paste. As a result, a cylindrical gap 27 is formed between the outer periphery of the cermet protection tube 13 and the outer frame 26. (3) The inside of the outer frame 26, that is, the cylindrical gap 27 is filled with a required amount of powdery molding material 48 made of a carbon-containing refractory material. (4) As shown in FIG. 3B, the length adjusting middle frame 25 is fitted inside the outer frame 26, and the pressing portion 29 of the lid portion 30 is further inserted.
After fitting the inside of the outer frame 26, the outer frame 26 and the lid 30
A sealing member 28 is attached to the boundary between the molding material 48 and the molding material 48 in the cylindrical gap 27 to form the hydraulic molding die 20.

(5) Cermet protection tube 13 and molding material 48
The water pressure molding die 20 equipped with and is loaded into the water pressure tank main body 38, the drain valve 40 is closed, the opening 37 is closed by the tank lid 39, and then the air supply / exhaust valve 44 and the water supply valve 42 are opened. The water supply pump 46 is driven to fill the water tank main body 38 with water. (6) When the water tank main body 38 is filled with water, the supply / exhaust valve 44 is closed, and the water supply pump 46 is further supplied until a predetermined pressure is reached.
Is driven for 5 to 10 minutes, for example. At this time, the outer frame 26 made of an elastic member is evenly pressured from the outer circumference by the water pressure in the water pressure tank main body 38, and the molding material 48 filled inside is compressed. (7) When the compression is completed, the water supply pump 46 is stopped, the air supply / exhaust valve 44 and the drain valve 40 are opened, and the water pressure tank main body 3
The water inside 8 is discharged, the tank lid 39 is opened, and the hydraulic forming die 20 is taken out. (8) Remove the pedestal 23 and the sealing member 28 attached to the boundary between the lid 30 and the outer frame 26 to pull up the lid 30, and further pull up the outer frame 26 and the length adjusting mold 25. hand,
Take out the cermet protection tube 13. At this time, the molding material 48 is formed integrally with the cermet protection tube 13. (9) After drying the molding material 48 pressure-molded together with the cermet protection tube 13 at, for example, about 150 to 300 ° C.,
Baking at a high temperature (preferably 800 to 1300 ° C.) forms the protective sleeve 15 integrated with the cermet protective tube 13.

As a result, the contact between the cermet protection tube 13 and the protection sleeve 15 is improved, and the molten metal 1 from between the cermet protection tube 13 and the protection sleeve 15 is improved.
4 and slag 16 can be prevented from entering, and embrittlement due to oxidation of the cermet protection tube 13 and reduction in life can be suppressed. Further, by forming the protective sleeve 15 in the state where the sheet-like heat insulating buffer layer 47 having a high porosity is provided on the outer periphery of the cermet protective tube 13, the cermet protective tube 1
3 provides a cushioning property between the protective sleeve 15 and the protective sleeve 15, absorbs the expansion force of the cermet protective tube 13, prevents cracks and cracks in the protective sleeve 15, and protects the inside of the protective sleeve 15 and the surface of the cermet protective tube 13. Oxidation can be further suppressed. Further, when the molding material 48 is pressure-molded by the hydraulic molding device 21, since the pressure is applied in the direction perpendicular to the longitudinal direction, variation in the density of the molding material 48 can be reduced.

As shown in FIG. 4, a molten metal immersion cylinder 50 according to a modified example of the first embodiment of the present invention includes an inner protective tube 12 having a sealed tip and a thermocouple 11 enclosed therein. Instead of the cermet protection tube 13 of the molten metal immersion cylinder 10 that is provided, there is provided a cermet protection tube 52 in which a tip end is opened and an immersion tube main body 51 for blowing an additive into the molten metal 14 is formed therein. A protective sleeve 53 is provided on the outer circumference of the cermet protective tube 52. The cermet protection pipe 52 is connected to, for example, an inert gas supply device 54, and in a state where the cermet protection pipe 52 is immersed in the molten metal 14, the inert gas supply device 54 passes through the immersion pipe body 51 and the opening 55 of the immersion pipe body 51. The inert gas is blown into the molten metal 14 from the above to agitate the molten metal 14 to remove oxygen in the molten metal 14. The step of forming the protective sleeve 53 on the cermet protective tube 52 is substantially the same as the step of forming the protective sleeve 15 on the cermet protective tube 13 of the molten metal immersion cylinder 10 by using the hydraulic forming mold 20, The description of the manufacturing process of the protective sleeve 53 is omitted. This allows
Cermet protection tube 5 with dip tube body 51 formed inside
2 and the protective sleeve 53 enhance the adhesion of their contact surfaces to each other, prevent the molten metal 14 and the slag 16 from entering between the cermet protective tube 52 and the protective sleeve 53, and embrittle the cermet protective tube 52 by oxidation. It is possible to suppress a decrease in life.

As shown in FIG. 5, a molten metal immersion cylinder 60 according to a second embodiment of the present invention uses a molten metal immersion cylinder 10 according to the first embodiment to protect a protective sleeve 15 from cermet. In place of the method of integrally press-molding the outer circumference of the tube 13, the outer circumference of the cermet protection tube 61 is covered with a protection sleeve 62 formed in a tubular shape in advance to form a tubular shape between the cermet protection tube 61 and the protection sleeve 62. The crevice 63 is filled with a filler 64 made of a carbon-containing refractory material,
The protective sleeve 62 and the protective sleeve 62 are integrally formed. The inner diameter of the protective sleeve 62 is set to a size that allows the cermet protective tube 61 to be fitted with a gap when the protective sleeve 62 is inserted inside the protective sleeve 62.
An internal protective tube 12 is inserted in the thermocouple 11 in an insulated state. The same components as those in the first embodiment are designated by the same names and the same reference numerals, and the description thereof will be omitted.

Here, the manufacturing method of the molten metal immersion cylinder 60 according to the second embodiment will be described with reference to FIGS.
(C), it demonstrates based on FIG. In addition, as a manufacturing facility, a support base 66 provided with a holding hole 65 opening on the upper surface is prepared. The inner diameter of the holding hole 65 is the cermet protection tube 61.
Can be loaded from above, and the depth is such that when the cermet protection tube 61 is loaded, the fixed position of the protection sleeve 62 is above the upper surface of the support base 66. Further, a vibrator 67 that generates vertical vibration of about 30 to 200 Hz is attached to the support base 66. Further, an annular stopper 69 having an through hole 68 having an inner diameter fitted to the outer circumference of the cermet protection tube 61 is prepared.

The mold for molding the protective sleeve 62 is a hydraulic mold 70 and a hydraulic molding device 21 similar to the hydraulic mold 20 described in the manufacturing process of the molten metal immersion cylinder 10 according to the first embodiment. (See FIG. 2) can be used. That is, the hydraulic molding die 70 has a steel pedestal portion 72 having a cylindrical protruding portion 71 having substantially the same outer diameter as the protective sleeve 62 in the portion excluding the peripheral portion, and at the center of the pedestal portion 72. Has a rod-shaped center core 73 that is slightly larger than the outer diameter of the cermet protection tube 61, for example, about 1 to 5 mm, and is concentric with the protruding portion 71. The projecting portion 71 has an inner diameter that a part of the projecting portion 71 fits in with no gap in the outer diameter, and has a cylindrical shape made of an elastic member such as urethane rubber, for example, 20% of the length of the cermet protection tube 61. The outer frame 74 is fitted inside the outer frame 74 by fitting a relatively long outer frame 74.
A cylindrical gap 75 surrounded by the core 73 is formed. On the upper side of the outer frame 74, the outer diameter of the protective sleeve 6 can be fitted inside the outer frame 74, and the inner diameter of the protective sleeve 6 can be fitted.
A length adjusting middle frame 76 for adjusting the length of 2 is provided. Further, above the outer frame 74, there is provided a rubber lid part 78 in which a pressing portion 77 having an outer diameter that can be fitted inside the outer frame 74 is projected downward. A sealing member (for example, vinyl tape) 79 is attached to the boundary between the pedestal portion 72 and the lid portion 78 and the outer frame 74, and the pedestal portion 72, the outer frame 74, and the lid portion 78 are integrated. A hydraulic molding die 70 is formed so as to seal the inside.

After the preparation of the manufacturing equipment is completed, the next step is carried out. (1) Lid 78 of Hydrostatic Mold 70 and Middle Frame 76 for Length Adjustment
Then, the cylindrical gap 75 formed in the hydraulic molding die 70 is filled with a powdery molding material 82 made of a carbon-containing refractory. (2) Put the length adjusting middle frame 76 in the tubular gap 75,
Further, after inserting the pressing portion 77 of the lid portion 78, a sealing member 79 is attached to the pedestal portion 72 and the boundary portion between the lid portion 78 and the outer frame 74, whereby the pedestal portion 72, the outer frame 74, and the lid portion 78. Together. (3) The hydraulic forming die 70 is loaded into the hydraulic forming apparatus 21, and the steps (5) to (9) of the manufacturing process of the molten metal immersion cylinder 10 according to the first embodiment are performed by substantially the same steps. Pressurize and fire to form the protective sleeve 62 in the cylindrical gap 75,
The cylindrical protective sleeve 62 is taken out from the hydraulic forming die 70.

(4) As shown in FIG. 6 (A), the tip of the cermet protection tube 61 is directed downward, and is inserted into the holding hole 65 of the support base 66 so that the root portion is projected upward to form a stopper. 69 is fitted on the outer circumference of the cermet protection tube 61 and placed on the upper surface of the support base 66. (5) A protective sleeve 62 is provided outside the cermet protective tube 61.
Is mounted, the protective sleeve 62 is positioned so as to be concentric with the cermet protective tube 61, and the protective sleeve 62 is placed on the stopper 69. (6) As shown in FIG. 6 (B), a cermet protection tube 61
A cylindrical gap 63 between the protective sleeve 62 and the protective sleeve 62 is filled with a powdery filler 64 made of a carbon-containing refractory. (7) 30 to 200H on the support base 66 by the vibrator 67
Vertical vibration of about z is applied for 10 to 30 minutes, for example, to increase the density of the filler 64. At this time, the filling material 6
Since the upper portion of 4 is slightly sunk, powder made of carbon-containing refractory is press-fitted into the sunk space, for example, a sealing material 83 formed in a clay shape with an alcohol-based binder to seal the space. In this state, the cermet protection tube 61 and the protection sleeve 6
2 is integrally formed by the filler 64.

(8) As shown in FIG. 6 (C), the cermet protection tube 61 together with the protection sleeve 62 is removed from the support base 66, the tip of the cermet protection tube 61 is placed upward, and the root portion is provided with a holding hole 65. Then, the clay-like sealing material 84 is press-fitted and sealed at the tip end side of the cylindrical gap 63. At this time, an adjustment table 85 whose height can be adjusted is placed on the support table 66, and the cermet protection tube 61 is inserted into the holding hole 65.
Make sure that the root of the can be loaded with a margin. (9) The cermet protective tube 61 is removed together with the protective sleeve 62 from the support base 66, and when a powdery filler 64, for example, is used in a drying oven, it is dried at a temperature of about 100 to 300 ° C. Get the body 60.

As a result, the protective sleeve 62 made of carbon-containing refractory can be formed in advance, and the cylindrical gap 63 between the protective sleeve 62 and the cermet protective tube 61 can be formed.
Then, the filling material 64 is filled in and the cermet protection tube 61 and the protection sleeve 62 are joined. Therefore, equipment such as a pressure press is unnecessary, and the processing cost can be reduced. Further, by using a refractory material made of the same carbon-containing refractory material as the protective sleeve 62 for the filler 64, the filler 64 and the protective sleeve 62 are easily adhered to each other. By vibrating and adjusting the density, it is possible to obtain the effect of imparting cushioning properties and absorbing the expansion force of the cermet protection tube 61.
Furthermore, the stress due to thermal expansion and thermal shock generated in the protective sleeve 62, the filler 64, and the cermet protective tube 61 when immersed in the molten metal can be relieved. When the conventional refractory cement is filled, it is liquefied by adding water, so it is cured at room temperature for about 24 hours until it solidifies, and then dried by a dryer at 100 to 300 ° C for about 15 hours to remove water. Then, it took about 40 hours in total. However, when dried in powder form without a binder, for example, at 150 to 300 ° C. for about 15 hours, when powdered with an alcohol-based binder and liquefied, it is necessary to dry at 70 to 300 ° C. for about 10 hours. Baking can be completed, the dried state can be completed, and the time required for drying can be shortened to about 1/3 that of the conventional case.

Molten metal immersion cylinder 6 according to the second embodiment.
In the manufacturing method of No. 0, the filler 64 is a powdery carbon-containing refractory, but it may be a liquid containing powder or a clay. In this case, the cylindrical gap 63 is filled with the filler 64.
All you have to do is stream the operation, and the automation of the work becomes easy. Furthermore,
When the filler 64 is clay-like, it rarely protrudes from the cylindrical gap 63 when it is pushed into the cylindrical gap 63, the dimensional accuracy can be made high, and the drying time and the filling work time can be shortened. . In addition, a filler 64 is inserted into the cylindrical gap 63 by press-fitting at least one end side of the cylindrical gap 63 with a viscous sealing material formed by kneading powder made of carbon-containing refractory and a binder. After the charging, the molten immersion dip tubular body 60 is stable in quality without sticking out or leaking from the tubular gap 63 in the drying step. Furthermore, the molten metal immersion cylinder 60 according to the second embodiment.
As a modification example, the tip of the cermet protection tube is opened, and the immersion tube body (see FIG. 4) for blowing the additive into the molten metal is formed inside the cermet protection tube, which is described as a modification example of the first embodiment. You may.

The method of manufacturing the molten metal immersion cylinder according to the embodiment of the present invention has been described above.
The present invention is not limited to the configurations described in the above embodiments, and includes other embodiments and modifications that are conceivable within the scope of the matters described in the claims. For example, in the second embodiment, an example has been described in which the tip of the cermet protection tube is charged into the holding hole of the support and then the filler is filled into the cylindrical gap. After first inserting into the holding hole of the support base,
The filler may be filled in the cylindrical gap. Further, after forming a protective sleeve on the outer circumference of the cermet protection tube, the outer circumference of the protective sleeve is coated with, for example, a stainless steel metal tubular body via a carbon-containing refractory material to prevent oxidation from slag or molten metal. The impact may be suppressed.

[0028]

In the molten metal immersion cylinder according to the present invention, a protective sleeve made of a refractory material is provided on the outer periphery of the cermet protection tube immersed in the molten metal, and the protective sleeve is made of a carbon-containing refractory body. In addition, since it is integrated with the cermet protection tube, even if it is immersed in high temperature molten metal, cracks or cracks will occur in the protection sleeve due to the difference in thermal expansion, and there will be a gap between the cermet protection tube and the protection sleeve. Can be prevented from expanding, and a high-quality molten metal immersion cylinder can be provided. In the molten metal immersion cylinder according to claim 2, a protective sleeve made of a refractory material is provided on the outer periphery of a cermet protective tube to be immersed in the molten metal, and the protective sleeve is made of a carbon-containing refractory material for cermet protection. Since it is integrally joined to the pipe through the filler made of carbon-containing refractory, the filler and protective sleeve may crack or break due to the difference in thermal expansion even when immersed in high temperature molten metal, or the cermet It is possible to prevent the gap between the protective tube and the protective sleeve from expanding, and it is possible to provide a high-quality molten metal immersion cylinder.

In the method for manufacturing a molten metal immersion cylinder according to claims 3 and 4, a step of pressure-molding a molding material made of a carbon-containing refractory material on the outer periphery of a cermet protection tube, and a pressure-molded molding material. And the step of forming a protective sleeve by firing, and since the protective sleeve that is integrated with the cermet protective tube is molded, it prevents molten metal or slag from entering between the cermet protective tube and the protective sleeve, It is possible to suppress brittleness due to oxidation of the protective tube and reduction in life.

Particularly, in the method for manufacturing the molten metal immersion cylinder according to the fourth aspect, since the protective sleeve is formed with the heat insulating buffer layer provided on the outer periphery of the cermet protective tube,
Between the cermet protective tube and the protective sleeve, a heat insulating buffer layer made of, for example, an aggregate bonded by a hydrolyzate of a metal alkoxide is formed. At this time, since the heat insulating buffer layer is formed in a sheet shape having a high porosity that does not reach a sintered state during the sintering operation of the protective sleeve, it provides cushioning between the cermet protective tube and the protective sleeve,
The effect of absorbing the expansion force of the cermet protection tube can be obtained, cracks and cracks of the protection sleeve can be prevented, and oxidation of the inside of the protection sleeve and the surface of the cermet protection tube can be further suppressed.

In the method for manufacturing a molten metal immersion cylinder according to any one of claims 5 to 7, a protective sleeve made of a carbon-containing refractory is disposed outside the cermet protective tube, and a tube between the cermet protective tube and the protective sleeve is provided. Since there is a step of filling a filling material made of a carbon-containing refractory into the interstices and molding a protective sleeve integrated with the cermet protective tube, and a step of firing the protective sleeve, equipment such as a pressure press can be installed. It is unnecessary and the processing cost can be reduced. Further, by using a refractory material made of the same carbon-containing refractory material as the protective sleeve, the filler and the protective sleeve are easily brought into close contact with each other, and the effect of absorbing the expansion force of the cermet protective tube can be obtained.

In the method of manufacturing a molten metal immersion cylinder according to the sixth aspect of the present invention, since the filler is in the form of powder, liquid containing powder, or clay, it is possible to shorten the time for drying the filler. The automation of the work is simplified, and the dimensional accuracy can be increased. In the method for manufacturing a molten metal immersion cylinder according to claim 7, a viscous sealing material formed by kneading a powder containing a carbon-containing refractory and a binder is press-fitted into at least one end of the cylindrical gap. Since there is a process to do so, after filling the cylindrical gap with the filler, the filler does not overflow or leak from the cylindrical gap during the drying process, and the quality of the molten metal immersion cylinder is stable. To do.

[Brief description of drawings]

FIG. 1 is a sectional view of a molten metal immersion cylinder according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a hydraulic forming apparatus used in the method for manufacturing the same molten metal immersion cylinder.

3 (A) and 3 (B) are explanatory views of a method for manufacturing the same molten metal immersion cylinder.

FIG. 4 is a cross-sectional view of a modified example of the same molten metal immersion cylinder.

FIG. 5 is a sectional view of a molten metal immersion cylinder according to a second embodiment of the present invention.

6 (A), (B), and (C) are explanatory views of a method for manufacturing the same molten metal immersion cylinder.

FIG. 7 is a cross-sectional view of a hydraulic forming apparatus used in the method for manufacturing the same molten metal immersion cylinder.

[Explanation of symbols]

10: Molten metal immersion cylinder, 11: Thermocouple, 12: Internal protective tube, 13: Cermet protective tube, 14: Molten metal, 15: Protective sleeve, 16: Slug, 17: Connection terminal, 18: Terminal box, 20: Hydraulic forming die, 21: hydraulic forming device, 22: protruding portion, 23: pedestal portion, 24: lower holding hole, 25: middle frame for length adjustment, 26: outer frame, 27: tubular gap, 28: Sealing member, 29: pressing portion, 30: lid portion, 37: opening portion, 3
8: Water tank main body, 39: Tank lid part, 40: Drain valve, 41: Drain port, 42: Water supply valve, 43: Water supply port, 4
4: Air supply / exhaust valve, 45: Air supply / exhaust port, 46: Water supply pump, 4
7: Thermal insulation buffer layer, 48: Molding material, 50: Immersion tube for molten metal, 51: Immersion tube body, 52: Cermet protection tube, 5
3: Protective sleeve, 54: Inert gas supply device, 55:
Opening part, 60: Molten metal immersion cylinder, 61: Cermet protective tube, 62: Protective sleeve, 63: Cylindrical gap, 64: Filler, 65: Holding hole, 66: Support, 67: Vibrator, 6
8: Through hole, 69: Stopper, 70: Hydraulic forming die, 7
1: protrusion part, 72: pedestal part, 73: core, 74: outer frame,
75: tubular gap, 76: middle frame for length adjustment, 77: pressing part, 78: lid part, 79: sealing member, 82: molding material, 8
3, 84: sealing material, 85: adjusting table

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masamune Mihara             26-89 Morishita-cho, Hachiman Nishi-ku, Kitakyushu City, Fukuoka Prefecture             Within Nippon Thermotech Co., Ltd. (72) Inventor Shuji Shike             4-7-1 Kudankita 4-chome, Chiyoda-ku, Tokyo             Kawashiro Brick Co., Ltd. F term (reference) 2F056 BP01 BP04 BP05                 4K056 AA02 AA05 AA06 FA12                 4K070 AB17 BE14 CC03

Claims (7)

[Claims] 1. A molten metal immersion cylinder having a protective sleeve made of a refractory material provided on the outer periphery of a cermet protective tube immersed in the molten metal, wherein the protective sleeve is made of a carbon-containing refractory molded body. An immersion cylinder for molten metal, which is integrated with a cermet protection tube. 2. A molten metal dipping cylinder in which a protective sleeve made of a refractory material is provided on the outer periphery of a cermet protection tube immersed in the molten metal, wherein the protective sleeve is made of a molded product of a carbon-containing refractory material. An immersion cylinder for molten metal, which is integrally joined to the cermet protection tube via a filler made of a carbon-containing refractory. 3. A protective sleeve made of a refractory material is provided on the outer circumference of a cermet protective tube to be immersed in the molten metal, and an inner protective tube of a thermocouple having a closed tip, or an immersion tube for blowing the additive into the molten metal with the open tip. A method of manufacturing a molten metal immersion cylinder applicable to a main body, comprising a step of pressure-molding a molding material made of a carbon-containing refractory material on the outer periphery of the cermet protection tube, and firing the pressure-molded molding material. And the step of forming the protective sleeve, and molding the protective sleeve integrated with the cermet protective tube, the method for producing a molten metal immersion cylinder. 4. The molten metal immersion cylinder manufacturing method according to claim 3, wherein the protective sleeve is formed in a state in which a heat insulating buffer layer is provided on the outer periphery of the cermet protection tube. A method for manufacturing a cylinder. 5. A protective sleeve made of a refractory material is provided on the outer periphery of a cermet protective tube to be immersed in the molten metal, and an inner protective tube of a thermocouple having a closed tip, or an immersion tube for blowing an additive into the molten metal with the open tip. A method for manufacturing a molten metal immersion cylinder applicable to a main body, wherein the protective sleeve made of a carbon-containing refractory is arranged outside the cermet protective tube, and a tube between the cermet protective tube and the protective sleeve. And a step of firing the protective sleeve, the step of molding the protective sleeve integrated with the cermet protective tube by filling a filler made of a carbon-containing refractory into the interstice gap, and the step of firing the protective sleeve. For manufacturing a dipping cylinder for automobile. 6. The method for manufacturing a molten metal immersion cylinder according to claim 5, wherein the filler is a powder, a liquid containing powder, or a clay. . 7. The method for manufacturing a molten metal immersion cylinder according to claim 5, wherein at least one end of the cylindrical gap has a viscosity formed by kneading a powder of carbon-containing refractory and a binder. A method for manufacturing a molten metal immersion cylinder, comprising a step of press-fitting a sealing material.