JP3247572B2 - Hot repair method for immersion pipe of RH type degasser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hot repair of an immersion pipe of an RH type degassing apparatus.

[0002]

2. Description of the Related Art An immersion pipe of an RH type degassing apparatus is an apparatus for directly immersing a tip portion into a ladle containing molten steel to perform refining.
It is easily damaged locally due to spalling due to thermal change.

[0003] Repair of a locally damaged portion of an immersion pipe of an RH type degassing apparatus is classified into internal repair and external repair of the immersion pipe. The internal repair is mainly performed by a castable press-fitting method. A method of spraying or patching a refractory of a patching material to repair it has been used.

[0004] The external repair of the immersion pipe of the RH type degassing apparatus will be described in detail. First, after roughly removing the slag adhered to the surface of the immersion pipe, a spraying material is locally applied to a damaged or cracked area. Repair has been performed by spraying or patching a patching material.

[0005] The spraying material used for this external repair is generally composed of an aggregate mainly composed of a magnesia raw material and one or two or more kinds of powdered sodium silicate or phosphate as a binder in an amount of about 2 to 5%. It is a compound that has been added, and the compound in a powder state is pressure-fed to a spray nozzle using compressed air, mixed with water at the spray nozzle, and sprayed. In addition, as a patching material, a bauxite fired product, fused alumina, a plastic material such as clay and a phosphate and a silicate as a binder are added to an aggregate such as spinel, and further, water is added and kneaded to form a kneaded material. Such a refractory in the form of a clay is hit against a locally damaged portion of the immersion pipe to be adhered.

[0006]

However, in the conventional method of externally repairing a immersion pipe of an RH type degassing apparatus using a spraying material or a patching material, when the surface temperature of the immersion pipe is as high as 600 ° C. or more, the spraying is performed. The loss due to the rebound of the sprayed material increases, and the adhesion rate decreases, and at the same time, the adhesive strength between the spray base material and the spray material on the bonding surface decreases. Similarly, when the temperature of the surface to be repaired of the patching material is increased, the adhesive strength is reduced. Also, the durability is reduced.

Accordingly, it is an object of the present invention to prevent a decrease in the adhesiveness of a sprayed material or a patching material in a hot repair method using a sprayed material or a patching material for an RH furnace degassing apparatus dipping tube.

[0008]

That is, an RH according to the present invention is provided.
Hot repair method of the formula degasser dip tube, was applied in advance or spraying the aluminum primary phosphate solution to be repaired site, characterized by patching the patching material containing silicate as a binder.

Furthermore, hot repair method of RH type degasser dip tube according to the present invention, after previously applying or spraying the aluminum primary phosphate solution to be repaired site, the spraying material containing silicate as a binder It is characterized by spraying.

[0010]

According to the hot repair method of the immersion pipe of the RH type degassing apparatus of the present invention, a spraying material or a patching material containing a silicate (sodium silicate, potassium silicate, water glass, etc.) as a binder is used as the repair material. Then, when the first aluminum phosphate, which acts as a gelling agent for the silicate as a binder, is previously applied or sprayed to the repaired site and its moisture is exhausted, the spraying material or the patching material is sprayed or patched thereon. Is what you do.

The patching material that can be used in the method of the present invention is not particularly limited, and any conventional patching material containing a silicate as a binder can be used. Of bauxite clinker, a plasticizer such as clay is added at 3 to 10% by weight, for example, about 5% by weight, a silicate powder is added at 2 to 4% by weight, and water is added at about 10 to 12% by weight. In addition, it is preferable to use a clay-shaped material.

The spraying material which can be used in the method of the present invention is not particularly limited, and any conventional spraying material containing a silicate as a binder can be used. It is mainly composed of magnesia raw material, to which 3 to 5% by weight of silicate powder is added.
It has been added to some extent.

According to the method of the present invention, before applying the above-mentioned patching material or spraying material to the damaged portion of the immersion pipe of the RH type degassing apparatus, a hot aqueous solution of aluminum phosphate is applied or sprayed to the damaged portion in advance. There are features. It is preferable to use an aqueous solution of aluminum phosphate having a concentration of 30% by weight or more, and the coating amount is preferably about 0.3 to 1 liter per 1 m ² of the damaged portion. If the coating amount is less than 0.3 liter per 1 m ^{2 of the} damaged site, it is not preferable because the coating effect of the first aluminum phosphate is small, and
Exceeding 1 liter has no associated effect. When the aqueous solution of the first aluminum phosphate is applied or sprayed to the damaged portion while hot, the water in the aqueous solution of the first aluminum phosphate evaporates due to the heat and adheres to the damaged portion as a white powder. Here, by applying a patching material or a spraying material containing a silicate as a binder, gelling (solidification) occurs rapidly, and the adhesive force of the patching material or the spraying material can be significantly improved.

[0014]

EXAMPLES The method for hot repairing the immersion pipe of the RH type degassing apparatus according to the present invention will be further described below with reference to examples. Example 1 About 1 m obtained by casting a castable
^2. A panel (alumina-spinel) having a thickness of 230 mm was set on the end wall of the furnace. After the temperature in the furnace was raised to 1000 ° C., the panel was taken out and the surface temperature became the temperature shown in Table 1. At this point, those sprayed with the first aluminum phosphate aqueous solution were sprayed with the first aluminum phosphate aqueous solution, and those not sprayed were sprayed with the spraying materials listed in Table 1 as they were. The spraying is performed by a method (wet spraying method) in which a spraying material obtained by previously kneading the composition and water shown in Table 1 is pumped to a spraying nozzle by a pump and sprayed using compressed air by the spraying nozzle. went. Table 1 shows the obtained results.
It is described together.

[0015]

[Table 1]

As is evident from the results shown in Table 1, this is an example of the present invention in which the aqueous solution of aluminum phosphate was sprayed in advance, and good adhesion was obtained despite the panel temperature of 620 to 630 ° C. The sprayed construction has good swelling, but has no swelling or dropping.

Next, about 50% of the riser pipe of the RH type degassing device is used.
An aqueous solution of aluminum phosphate monobasic (aluminum phosphate monobasic: water = 50: 50) was applied to two local damage sites (surface temperature about 500 ° C.) of 0 mmφ × 30 mm depth at a rate of about 0.3 liter / water.
only spray at a rate of m ^2, and blowing of the sprayed material Table 1 after 1 minute. 60 minutes after spraying, the riser was used (use time: about 30 minutes / time). Although the riser repaired by the above method did not cause any problem even after being used three times, in the conventional repair method which was not sprayed with the aqueous solution of aluminum phosphate first, a part of the riser was partly observed.

Example 2 Using a patching material having the composition shown in Table 2, its hot adhesive strength was measured. As shown in FIG. 1, the adhesive strength was determined by previously casting an aqueous solution of aluminum phosphate (aluminum phosphate: water) on a castable refractory plate (alumina-spinel: 230 × 115 × 30 mm) (1) heated to a predetermined temperature as shown in FIG. = 50: 50), and then an inner diameter of 80 mm
A patch material filled in a ring (2) having a thickness of φ and a thickness of 30 mm was patted lightly and left for 5 minutes, and then the shear strength at the bonding surface was measured using the apparatus shown in FIG. In the apparatus shown in FIG. 2, a structure in which a load (7) is applied to the sample (3) in the ring (2) through a fulcrum (6), and a force 5 times the load (7) is applied by the push rod (4). It has become. Therefore,
The adhesive strength described in Table 2 is obtained by multiplying the load when the sample (3) was peeled off from the castable refractory board by five times.

[0019]

[Table 2]

As is evident from the results shown in Table 2, B and D of the present invention had remarkably excellent adhesive strength.

[0021]

According to the method of the present invention, when the immersion pipe of the RH type degassing apparatus is hot-repaired with a silicate-containing patching material or a spraying material as a binder, the silicate gels in the damaged portion in advance. Since the aqueous solution of aluminum phosphate acting as an agent is sprayed or applied, the adhesiveness of the spraying material or patching material used can be significantly improved. It should be noted that the method of the present invention can be applied to a reflux pipe or a D
The present invention can also be applied to hot repair of a suction pipe of an H furnace.

[Brief description of the drawings]

FIG. 1 is a schematic view showing how a punching material sample is set on a castable plate in Example 2.

FIG. 2 is a schematic view of an apparatus used for measuring adhesive strength in Example 2.

[Explanation of symbols]

 1 Castable plate 2 Ring 3 Punching material (sample) 4 Push rod 5 Balance weight 6 Load

Continued on the front page (73) Patent holder 000001199 Kobe Steel, Ltd. 1-3-18, Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture (73) Patent holder 000001971 Shinagawa White Brick Co., Ltd. 4-chome, Kudankita, Chiyoda-ku, Tokyo 1-7 (72) Inventor Yoshikatsu Furuno 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Japan Nippon Kokan Co., Ltd. (72) Inventor Noboru Murakami 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Naohiko Murakami 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Within Nippon Kokan Co., Ltd. (72) Inventor Masahiro Ariyoshi 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture Mizushima Kawasaki Steel Corporation Inside the steelworks (72) Inventor Masao Nambu 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref. Kawasaki Steel Corporation Mizushima Works (72) Inventor Yoshikazu Kubo 1850 Minato, Wakayama-shi, Wakayama Sumitomo Metal Industries, Ltd. Inside Wakayama Works (72) Inventor Yasushi Satake Wakayama Prefecture 1850 Minato, Wakayama City Sumitomo Metal Industries Co., Ltd.Wakayama Steel Works (72) Inventor Osho Akira 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel Co., Ltd.Kakogawa Works (72) Inventor Toshiyuki Okazaki 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Address Kobe Steel, Ltd.Kakogawa Works (72) Inventor Masashi Mori 2-2-1 Otemachi, Chiyoda-ku, Tokyo Shinagawa White Brick Co., Ltd. (72) Inventor Yasuo Takeshita 2--2, Otemachi, Chiyoda-ku, Tokyo No. 1 Shinagawa White Brick Co., Ltd. (56) References JP-A-51-66206 (JP, A) JP-A-63-95168 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB) Name) C21C 7/10

Claims (2)

(57) [Claims] 1. A hot repair method of RH type degasser dip tube, was applied in advance or spraying the aluminum primary phosphate solution to be repaired site to patching patching material containing silicate as a binder A hot repair method for a submerged RH type degassing apparatus. 2. A RH type hot repairing method of the degasser dip tube, was applied in advance or spraying the aluminum primary phosphate solution to be repaired site that blowing spray material containing silicate as a binder A hot repair method for a submerged RH type degassing apparatus.