JPH10230354A - Reinforcing method of refractory product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient reinforcing effect and to improve workability. SOLUTION: A sliding gate plate 10a is arranged within a mold 20, and a continuos band shape of molding space 22 is formed in its outer periphery. After a molten metal 23 is filled into the forming space 22, the filled molten metal 23 is solidified, and the reinforcing band consisting of the solidified metal 25 is formed in the outer periphery of plate 10a. A compressing force is applied toward the center of the plate 10a with the reinforcing band, whereby the plate 10a is reinforced.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a method for strengthening a refractory product, and more specifically, to prevent a crack or a crack from occurring in a refractory product (for example, a sliding gate plate) used for a molten metal discharging device in a continuous casting device. The present invention relates to a method for strengthening a refractory product.

[0002]

2. Description of the Related Art Since refractory products of this type are repeatedly used while hot, cracks and cracks are likely to occur during use due to thermal stress. Therefore, in order to prevent the occurrence and expansion of these cracks and cracks, conventionally, various methods have been proposed for strengthening the refractory product by applying a compressive force to the refractory product by winding a metal band around the periphery of the refractory product. I have.

[0003] Japanese Patent Publication No. 58-48835 discloses that, while heating and applying a tensile force to a strip-shaped thin iron plate on the outer periphery of a refractory product such as a plate brick or a nozzle brick, a wound end is welded. A method for strengthening a refractory product, wherein the method is a hoop. Tokiko 58
No.-48835 further discloses that "winding is performed while heating and applying a tensile force to a strip-shaped thin iron plate around the outer periphery of a refractory product such as a plate brick or a nozzle brick, and welding portions are provided at intervals in the middle of the winding. And a method for strengthening a refractory product characterized by welding a tightened end to form a hoop.

Further, Japanese Patent Application Laid-Open No. 58-157572 discloses that "a steel ring having an inner peripheral surface provided with a predetermined interference fitting with an outer peripheral surface of a refractory is heated and expanded and fitted on the outer periphery of the refractory. A method for reinforcing a refractory, characterized in that the refractory is reinforced by tightly fixing the steel ring after cooling.

[0005]

The above-mentioned conventional reinforcing method has the following problems. In other words,
In each of the methods disclosed in JP-A-48835 and JP-A-58-157572, a rigid metal band (a thin steel plate or a steel ring) manufactured in advance is mounted on the outer peripheral surface of a refractory product. It is inevitable that a relatively large gap is formed between the outer peripheral surface of the refractory product and the wound metal band. As a result, in the wound metal band, a compressive force cannot be applied uniformly to the entire outer peripheral surface of the refractory product, and there is a problem that a desired reinforcing effect cannot be obtained.

In order to avoid this problem, it is necessary to reduce the unevenness by polishing the outer peripheral surface of the refractory product before the mounting work of the metal band, but this requires extra work such as polishing. Workability decreases.

In the method disclosed in Japanese Patent Publication No. 58-48835, (1) a rigid metal band is pulled,
(2) tightening a metal band around the outer peripheral surface of the refractory product;
(3) The work of welding the tightened end of the metal band needs to be performed hot. According to the method disclosed in JP-A-58-157572, (1) heating of a metal strip,
(2) It is necessary to perform the operation of hammering the heated and expanded metal strip into the outer peripheral surface of the refractory product in a hot state. Therefore, each of these methods has a problem that workability is poor.

It is an object of the present invention to provide a method for reinforcing a refractory product which has a sufficient reinforcing effect and good workability.

It is another object of the present invention to provide a method of reinforcing a refractory product that can sufficiently obtain a reinforcing effect even if the outer peripheral surface of the refractory product has relatively large irregularities.

[0010]

[Means for Solving the Problems]

(1) A method for strengthening a refractory product according to the present invention includes the steps of arranging a refractory product in a mold and forming a continuous band-shaped molding space around the periphery of the refractory product; Filling and forming a metal reinforcing band around the periphery of the refractory product by solidifying the molten metal filled in the molding space, wherein the metal reinforcing band of the refractory product The refractory product is reinforced by applying a compressive force toward the center.

(2) Preferably, the mold has a depression having an open upper surface, wherein the refractory product is disposed in the depression from above, and the molten metal is placed in the molding space above the depression. Filled from.

(3) Examples of the refractory product include a sliding gate plate used in a molten metal discharging device in a continuous casting device, but other refractory products (for example, upper and lower nozzles) can also be used. is there.

As the mold, any mold can be used as long as it can form a continuous band-shaped molding space on the outer periphery of the refractory product when the refractory product is placed in the mold.

The molding space is formed on the outer periphery of the refractory product, and its shape is sufficient if it is a continuous band. The shape and size of the molding space are arbitrarily set according to the shape of the refractory product and the shape of the metal reinforcing band.

As the molten metal, a metal obtained by heating and melting a metal having a lower melting point than that of the refractory product and having a mechanical strength capable of reinforcing the refractory product after solidification is optionally used. it can. For example, those obtained by heating and melting copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy) are preferable.

The shape and size of the metal reinforcing strip are determined by the shape and size of the molding space.

(4) In the method for reinforcing a refractory product according to the present invention, the molten metal is filled in the continuous band-shaped molding space formed in the mold, and the molten metal is solidified to form the refractory. A metal reinforcing band is formed on the outer periphery of the product. For this reason, the shrinkage of the molten metal at the time of solidification allows the metal reinforcing band to adhere to the outer peripheral surface of the refractory product, and apply a compressive force uniformly to the entire outer peripheral surface. Therefore, a desired reinforcing effect can be obtained effectively.

Further, even if relatively large irregularities exist on the outer peripheral surface of the refractory product, the molten metal solidifies along the irregularities to form the metal reinforcing band. As a result, a sufficient reinforcing effect can be obtained even if the irregularities are relatively large.

Furthermore, after the refractory product is placed in the mold, it is only necessary to fill and solidify the molten metal in the molding space, so that the operation can be performed easily. That is, workability is good.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the embodiment described here, a sliding gate plate used for a molten metal discharging device in a continuous casting device is used as a “refractory product”. However, the scope of the present invention is not limited to the sliding gate plate, and it goes without saying that the present invention can be applied to other refractory products (for example, upper and lower nozzles).

In FIG. 2, reference numeral 10 denotes a sliding gate plate (hereinafter abbreviated as "plate") reinforced by the method of the present invention. This plate 10
The main body 11 has a substantially rectangular flat plate shape.
And a substantially cylindrical protruding portion 12 formed on one side surface 16. No protrusion is formed on the other side surface 17 of the main body 11, and the side surface 17 is flat over the entire surface.

The refractory material from which the plate 10 is formed may be any known ceramic, but here is of high alumina.

In this case, the size of the main body 11 of the plate 10 is about 49 cm × about 20 cm × about 4 cm × length × width × thickness.
cm. The size of the protrusion 12 is diameter × height (height from the side surface 16) = about 12 cm × about 2 cm.

A through-hole 13 is formed inside the main body 11 so as to extend perpendicularly and through the main body 11 along the center axis thereof. The through-hole 13 has a function of passing molten metal for casting.

The side surface 16 of the main body 11 is covered with a metal cushion material 15 on almost the entire surface except for the protrusion 12. Here, the cushion material 15 is an iron plate having a thickness of about 3 mm.

A ring-shaped iron reinforcing band 14 is mounted on the outer peripheral surface 18 of the main body 11. This reinforcing band 14
Almost the entire outer peripheral surface 18 is covered while applying a compressive force toward the center of the main body 11. Reinforcing band 14 is outer peripheral surface 1
8 and there is no gap between them. The width (height) of the reinforcing band 14 is about 3 cm.

Next, a method of manufacturing the plate 10 having the above configuration will be described with reference to FIGS.

First, as shown in FIG. 3A, a plate 10a is manufactured by a known arbitrary method. This plate 10a corresponds to the reinforced plate 10 shown in FIG.
And has a configuration in which only the iron reinforcing band 14 of the outer peripheral surface 18 is removed from the outer peripheral surface 18.

On the other hand, a mold 20 having a depression 21 capable of accommodating the plate 10a is manufactured. Here, mold 2
0 is a so-called "sand mold" formed from known suitable foundry sand. However, other molds (for example, alumina, silica,
Magnesia, chromium, and other synthetic inorganic materials) can also be used.

Next, the plate 10a is fitted and arranged inside the recess 21 of the mold 20 with the projecting portion 12 thereof facing upward. At this time, as shown in FIG. 3B and FIG. 1, a ring (continuous band) -shaped molding space is provided inside the recess 21 around the plate 10a when the plate 10a is accommodated, in other words, outside the outer peripheral surface 18. 22 are formed. Side 1 of plate 10a
7 is in contact with the bottom surface of the depression 21 of the mold 20. The thickness of the molding space 22, that is, the outer peripheral surface 1 of the plate 10a
The distance between 8 and the inner wall of the depression 21 of the mold 20 opposed thereto is set according to the thickness of the iron reinforcing band 14 to be obtained, and is, for example, 4 to 6 mm.

Subsequently, iron having a melting point lower than that of the refractory material (high alumina) constituting the plate 10a is heated to a temperature higher than the melting point (for example, 1600 ° C.) and melted to form a molten metal 23. . Thereafter, as shown in FIG. 3C, the molten metal 23 is filled into the continuous band-shaped forming space 22 using a funnel-shaped guide device 24. Molten metal 23
Can be arbitrarily selected as long as it can perform a desired function as the reinforcing band 14 after solidification. Here, iron is used.

Then, the mold 20 filled with the molten metal 23 in the molding space 22 is left at room temperature, and the molten metal 23
Is cooled and solidified. Thus, the ring-shaped solidified metal 25 is cast in the forming space 22 as shown in FIG. The time required for solidification depends on the type of the molten metal 23 and the thickness and width of the molding space, but is several minutes when the thickness of the molding space is about 4 to 6 mm and the width is about 3 mm.

In this cooling / solidification step, the molten metal 23 contracts. Therefore, the solidified metal 25 is in close contact with the outer peripheral surface 18 of the plate 10a. At the same time, a compressive force is applied toward the center of the main body 11 of the plate 10a, and as a result, a compressive stress is generated inside the main body 11.

Finally, the mold 20 is broken by an appropriate method, and the plate 10a is taken out from the depression 21. Since the solidified metal 25 is in close contact with the outer peripheral surface 18 of the plate 10a, it is taken out together with the plate 10a. The solidified metal 25 fixed to the outer peripheral surface 18 of the plate 10a
It becomes the reinforcement band 14. Thus, the reinforced plate 10 shown in FIG. 2 is obtained.

As described above, in the strengthening method of the present invention, the molten metal (that is, molten iron) 23 is filled in the ring-shaped molding space 22 formed in the mold 20 and the molten metal 23 is solidified. Thereby, the reinforcing band 14 is formed on the outer periphery of the plate 10a. For this reason, the reinforcing band 14 comes into close contact with the outer peripheral surface 18 of the plate 10a, and it becomes possible to uniformly apply a compressive force toward the center of the plate 10a to the entire outer peripheral surface 18. Therefore, a reinforcing effect equivalent to that of the above-described conventional method can be obtained with the reinforcing band 14 which is thinner than that. That is, since the reinforcing effect of the reinforcing band 14 can be effectively used, the plate 10
a sufficient reinforcing effect on the a.

Even if there are relatively large irregularities on the outer peripheral surface 18 of the plate 10a, the molten metal 23 solidifies along the irregularities to form the reinforcing band 14. As a result, even if the irregularities on the outer peripheral surface 18 are relatively large, the outer peripheral surface 18 can be flexibly deformed along the irregularities. Therefore,
The molten metal 23 adheres to the irregularities on the outer peripheral surface 18 and a desired reinforcing effect can be efficiently obtained.

Further, a necessary operation is to arrange the plate 10 a in the mold 20 and then put the molten metal 2 in the molding space 22.
After the filling of No. 3, it is simply left at room temperature to solidify. As in the conventional reinforcing method, it is not necessary to perform a troublesome operation such as winding around the outer peripheral surface 18 of the plate 10a while pulling the metal band or hammering the heated and expanded metal band. As a result, the work of strengthening the plate 10a is simplified, and workability is extremely improved.

It is to be noted that the dimensions of the reinforcing band 14 for the same plate 10a can be adjusted simply by replacing the mold with another mold 20 having a different molding space 22, and the reinforcing band 14 suitable for the different plate 10a can be selected. There is also an advantage that it can be performed simply and accurately simply by replacing the mold 20.

[Confirmation Test] In order to confirm the effect of the reinforcing method of the present invention, a visual observation test and a spalling test were performed under the following conditions.

(Example 1) A reinforcing plate 1 having the structure shown in FIG. 2 and having a reinforcing band 14 made of iron and having a thickness of 4.5 mm.
After preparing No. 0a, it was reinforced according to the process shown in FIG. 3 to produce the reinforced plate 10 of FIG. 10 samples
It was made into pieces.

(Example 2) A reinforced plate 10 was manufactured in the same manner as in Example 1 except that the thickness of the reinforcing band 14 made of iron was 6.0 mm. The number of samples was ten.

(Comparative Example 1) A reinforcing plate having the structure shown in FIG. 2 and having a thickness of 4.5 mm, the same as that of the iron reinforcing strip of Example 1, was disclosed in Japanese Patent Application Laid-Open No. 58-157572. Made according to That is, the reinforcing band made of iron
After being heated and expanded to 0 ° C., it was fitted to the outer peripheral surface of the plate. Thereafter, the reinforcing band and the plate were cooled to room temperature to produce a reinforcing plate. The number of samples was ten.

Comparative Example 2 A reinforced plate was produced in the same manner as in Comparative Example 1, except that the thickness of the reinforcing band made of iron was 6.0 mm, which is the same as in Example 2. The number of samples was ten.

(Visual observation test) In Examples 1 and 2,
As shown in FIG. 4, the outer peripheral surface 18 of the plate 10 and the metal reinforcing band 14 were in close contact with each other, and no gap was observed between them. In contrast, in Comparative Examples 1 and 2, it was observed that a gap 19 was formed between the outer peripheral surface 18 of the plate 10 and the reinforcing band 14, as shown in FIG. The average value is 0.10 m in Comparative Example 1.
m, the maximum value is 0.25 mm, and the average value is 0.
09 mm, the maximum value was 0.23 mm.

The reason why Comparative Example 2 is smaller than Comparative Example 1 is that Comparative Example 2 has a larger thickness of the reinforcing band 14.

(Spalling Test) As shown in FIG. 6 (a), the two reinforcing plates 10 of Example 1 or 2 were placed so that their flat side surfaces 17 faced and were in contact with each other. Furthermore, the upper nozzle 50 is fixed to the upper plate 10,
The lower nozzle 60 was fixed to the lower plate 10. Thus, these plates 10 were set in an actual use state. Then, the tip of the gas burner 71 is connected to the upper nozzle 50.
And the upper and lower plates 10 were heated. The heating temperature was 1550 ° C and the heating time was 5 minutes.

After removing the gas burner 71, an air flow 72 at room temperature was supplied into the through-hole 52 of the upper nozzle 50, and the upper and lower plates 10 were cooled for 30 minutes. Then, the two plates 10 and the upper and lower nozzles 50 and 60 were disassembled, and each plate 10 was visually observed for cracks or cracks.

The heating temperature was measured using a thermocouple at a position 10 mm inward from the entrance of the through-hole 13 by using a thermocouple.

The same measurement was performed for Comparative Examples 1 and 2.

FIGS. 7 and 8 show the obtained results. In the reinforcing plate 10 of the first embodiment, as shown in FIG. 7A, one crack 41 (length: about 10 m) is formed from the through-hole 13.
m) had occurred.

In the reinforcing plate 10 of the second embodiment, FIG.
As shown in (b), one crack 41 is formed from the through-hole 13.
(Length: about 4 mm). This point was the same as in Example 1, but the length of the crack 41 was considerably shorter than in Example 1. This is because the thickness of the reinforcing band 14 is 4.
In contrast to 5 mm, in Example 2, it is 6.0 mm, which reflects that the reinforcement level of Example 2 is higher than that of Example 1.

FIG. 8 shows the occurrence of cracks in Comparative Examples 1 and 2.
Shown in In the reinforced plate of Comparative Example 1, as shown in FIG. 8A, three cracks 41 (lengths: about 8, 7, and 18 mm, respectively) were formed from the through holes 13.

FIG. 8B shows the reinforcing plate of Comparative Example 2.
As shown in FIG. 3, one crack 41 (length:
(Approximately 10 mm). This point was the same as Comparative Example 1, but the length of the crack 41 was considerably shorter than Comparative Example 1. This reflects that the thickness of the reinforced belt is 4.5 mm in Comparative Example 1, whereas it is 6.0 mm in Comparative Example 2, and as a result, the reinforced level is higher than in Comparative Example 1. It was done.

As is clear from comparison between Example 1 and Comparative Example 1 and Example 2 and Comparative Example 2 using the reinforcing bands having the same thickness, it is clear that the reinforcing method of the present invention has a higher reinforcing effect. Was confirmed. This corresponds to Example 1 and Example 2.
This means that a compressive force could be applied to the plate more efficiently than in Comparative Examples 1 and 2.

[0055]

As described above, according to the method for reinforcing a refractory product of the present invention, a sufficient reinforcing effect can be obtained and workability is good. Further, even if the outer peripheral surface of the refractory product has relatively large irregularities, a sufficient reinforcing effect can be obtained.

[Brief description of the drawings]

FIG. 1A is a plan view showing a state in which a sliding gate plate is disposed in a mold used in the method of the present invention, and FIG. 1B is a cross-sectional view along the line AA.

FIG. 2A is a plan view of a sliding gate plate reinforced by the method of the present invention, and FIG. 2B is a cross-sectional view taken along the line BB.

FIG. 3 is a schematic sectional view showing the method of the present invention in the order of steps.

FIG. 4 is an enlarged plan view of a portion C in FIG. 2;

FIG. 5 is an enlarged plan view of a portion corresponding to a portion C in FIG. 2 of the sliding gate plate of the comparative example.

FIGS. 6A and 6B are cross-sectional views showing a spalling test of a sliding gate plate strengthened by the method of the present invention, wherein FIG. 6A shows a state when the sliding gate plate is heated, and FIG. Indicates the situation.

FIG. 7A is a schematic plan view showing a result of a spalling test of a sliding gate plate reinforced by the method of the first embodiment of the present invention, and FIG. 7B is a schematic plan view of the sliding gate plate strengthened by the method of the second embodiment of the present invention; Sliding gate
It is a schematic plan view which shows the spalling test result of a plate.

8A is a schematic plan view showing a result of a spalling test of a sliding gate plate reinforced by the method of Comparative Example 1, and FIG. 8B is a schematic plan view of the sliding gate plate reinforced by the method of Comparative Example 2. It is a schematic plan view showing a spalling test result.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Sliding gate plate after reinforcement 10a Sliding gate plate before reinforcement 11 Main part of sliding gate plate 12 Projection of sliding gate plate 13 Through-hole of sliding gate plate 14 Metal reinforcing band of sliding gate plate Reference Signs List 15 Cushion material of sliding gate plate 16, 17 Side surface of sliding gate plate 18 Outer peripheral surface of sliding gate plate 19 Clearance between outer peripheral surface of sliding gate plate and metal reinforcing plate 20 Mold 21 Mold dent 22 Molding space 23 Molten metal 24 molten metal guide device 25 solidified metal 50 upper nozzle 51 upper nozzle main body 52 upper nozzle through-hole 60 lower nozzle 61 lower nozzle main body 62 lower nozzle Flow hole 63 Metal casing 71 Gas burners 72 cooling air

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyonori Hara 1 Minami Fuji, Ogakie-cho, Kariya City, Aichi Prefecture Inside Toshiba Ceramics Co., Ltd. (72) Inventor Osamu Morita 1 Minami Fuji, Ogakie-cho, Kariya City, Aichi Prefecture Toshiba (72) Inventor Kenichi Mukaiyama 1 Minamito, Ogakie-cho, Kariya-shi, Aichi Pref.

Claims (3)

[Claims] A step of arranging a refractory product in a mold to form a continuous band-shaped molding space around the periphery of the refractory product; a step of filling the molding space with a molten metal; Solidifying the molten metal filled in to form a metal reinforcing band on the outer periphery of the refractory product, applying a compressive force toward the center of the refractory product by the metal reinforcing band. A method for strengthening a refractory product, the method comprising reinforcing the refractory product. 2. The mold has a recess with an open top, wherein the refractory product is disposed inside the recess from above, and the molten metal is filled into the molding space from above. The method for strengthening a refractory product according to claim 1. 3. The method for strengthening a refractory product according to claim 1, wherein the refractory product is a sliding gate plate.