JP2019171401A - Interior body and method for producing the same - Google Patents

Abstract

To prevent the remaining of a joint filler used when an interior body is fitted to a tuyere at the inner hole face of the tuyere or reduce the remaining degree thereof.SOLUTION: The region at least in contact with the inner hole face of a tuyere via a joint filler in the outermost peripheral surface of an interior body 1 is provided with an adhesive layer 3 having a function of being adhered with the joint filler.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an interior body such as a gas blowing plug or an upper nozzle that is fitted to a tuyere installed in a molten metal container such as a ladle or a tundish.

  Since the gas blowing plug blows gas into the molten metal, the upper nozzle is installed at the bottom of the molten metal container to discharge the molten metal. These are fitted and attached to tuyere installed at the bottom of the molten metal container. In the present specification, an object fitted and installed in such a tuyere is referred to as an “interior body”.

  Generally, tuyere has a longer life than its interior. That is, the interiors such as the gas blowing plug and the upper nozzle are exchanged several times for the same tuyere. At this time, the inner body is brought into close contact with the inner hole surface of the tuyere via a joint material in order to prevent the molten metal from leaking from between the tuyere. When replacing the inner body, the inner hole surface of the tuyere matches or resembles the outer shape of the inner body, or the surface unevenness is less than the thickness of the joint so that the inner body is in close contact with the joint. It is necessary to maintain the smoothness that is.

  However, at the time of removal of the interior body, at least a part of the joint material and inclusions such as molten metal or slag remain on the inner hole surface of the tuyere, so that the necessary smoothness is achieved on the inner surface of the tuyere. It may not be secured.

  The remaining joint material is generally removed by being mechanically destroyed by, for example, an apparatus disclosed in Patent Document 1, a cleaning method, and various other apparatuses and methods. However, removal of such non-uniform residues can take unforeseen time and effort and disrupt the use cycle of the molten metal container. Furthermore, the tuyere itself is often damaged during such mechanical destruction or removal. Damage to the tuyere increases the risk of reducing the life of the tuyere and surrounding refractory layers, or causing molten metal leakage from the tuyere itself and the tuyere.

JP 7-256440 A

  The problem to be solved by the present invention is to prevent or reduce the remaining degree of joint material used when fitting and attaching the interior body to the tuyere. is there.

  The outermost peripheral surface of the interior body in contact with the inner hole surface of the tuyere through the joint material is roughly classified into (a) a form of a metal plate (the outer surface of the metal case) and (b) a form of a refractory.

  The present invention is based on improving adhesion between the metal plate or refractory on the outermost peripheral surface of the interior body and the joint material when the interior body is removed from the tuyere.

  The adhesive layer adheres the adhesive layer to the refractory of the interior body or the metal plate and the joint material by sintering or reaction, mechanical entanglement, etc. It adheres by infiltration into and subsequent solidification.

That is, this invention is the manufacturing method of the following 1 to 6 interior bodies and the 7 to 9 interior bodies.
1.
An interior body fitted and attached to a tuyere of a molten metal container, wherein the joint material and the outermost peripheral surface of the interior body are in contact with at least the inner hole surface of the tuyere through the joint material. An interior body provided with a layer having a function of adhering (hereinafter referred to as “adhesive layer”).
2.
2. The tuyere interior according to 1, wherein the adhesive layer contains one or more selected from silicate, phosphorus, or sulfur.
3.
The interior body according to 2, wherein the silicate is derived from water glass.
4).
The adhesive layer has a total of 10 masses of refractory raw material particles or metal particles of at least one kind of alumina, alumina-silica, zircon, spinel or silicic acid having a particle size of 0.5 mm or less. The interior body according to any one of 1 to 3, which is contained in an amount of 1% or less.
5.
The interior body according to 4, wherein the metal particles are iron or iron-based alloy particles.
6).
6. The interior body according to any one of 1 to 5, wherein a maximum thickness of the adhesive layer is 0.5 mm or more and 2 mm or less.
7.
7. The method for manufacturing an interior body according to any one of 1 to 6, wherein an adhesive layer is formed of a material containing silicate on the outermost peripheral surface of the interior body, and 100 ° C. after the formation of the adhesive layer. The manufacturing method of an interior body including the process of heat-processing above.
8).
8. The method for manufacturing an interior body according to 7, wherein the material containing silicate is water glass.
9.
9. The method for manufacturing an interior body according to 8, wherein the water glass has a SiO ₂ / R ₂ O (R: alkali metal) molar ratio of 2.35 or more and 3.35 or less.

According to the present invention, the adhesive layer adheres the joint material to the outermost metal plate or refractory of the interior body by sintering or reaction, mechanical entanglement, or the like, or the adhesive layer has low melting or the joint material and the interior body outer periphery. The joint material and the outermost peripheral surface of the interior body can be bonded by infiltration into the refractory structure and subsequent solidification.
As a result, when the interior body is removed from the molten metal container, the joint material is removed together with the interior body and can be prevented from remaining on the inner hole surface of the tuyere, or the remaining joint material can be reduced. it can.
This eliminates or reduces the need for operations and processes, such as applying mechanical shocks to the inner hole surface of the tuyere, which were necessary to remove the remaining joint material. Time and labor can be reduced. Moreover, damage to the tuyere can be prevented or reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional image figure which shows embodiment of the interior body of this invention, (a) is a gas blowing plug, The outermost peripheral surface is a form of a metal plate (metal case), (b) is a gas blowing plug. The outermost peripheral surface is a form of a dense refractory, and (c) is an upper nozzle, which is composed only of a refractory. It is a cross-sectional image figure explaining a state when the plug for gas blowing (interior body) of Drawing 1 (b) is pulled out from a tuyere. It is a cross-sectional image figure explaining the state when pulling out the plug for gas blowing (comparative example) which is not provided with the contact bonding layer from a tuyere.

FIG. 1 shows an embodiment of the interior body of the present invention.
An inner body 1 shown in FIG. 1A is a gas blowing plug, and its outermost peripheral surface is a metal plate (metal case) 2, and the outer peripheral side of the metal plate (metal case) 2 that is the outermost peripheral surface. Is provided with an adhesive layer 3. A dense refractory layer 4 is disposed on the inner peripheral side of the metal plate (metal case) 2, and a breathable refractory layer 6 is provided on the inner peripheral side of the dense refractory layer 4 via a sealing material 5. Has been placed. A gas introduction pipe 7 is connected to the breathable refractory layer 6, and gas is discharged from the upper end surface of the breathable refractory layer 6.

  The inner body 1 shown in FIG. 1 (b) is a gas blowing plug, the outermost peripheral surface of which is a dense refractory layer 4, and is bonded to the outer peripheral side of the dense refractory layer 4 which is the outermost peripheral surface. Layer 3 is provided. A metal plate (metal case) 2 is disposed on the inner peripheral side of the dense refractory layer 4, and a breathable refractory layer 6 is disposed on the inner peripheral side of the metal plate (metal case) 2.

  The interior body 1 shown in FIG.1 (c) is an upper nozzle, and is comprised only with the refractory. And the adhesion layer 3 is provided in the outer peripheral side (outermost peripheral surface) of the upper nozzle which consists of this refractory.

  These interior bodies 1 are fitted and attached to the tuyere 8 of a molten metal container via joints 9 as shown in FIG. Since the adhesive layer 3 provided on the outermost peripheral surface of the interior body 1 is a layer having a function of adhering to the joint material 9, the interior body 1 is removed from the tuyere 8 as shown in FIG. When pulling out, the joint material 9 can be pulled out together with the inner body 1 without leaving the joint material 9 in the tuyere 8.

The specific action of this adhesive layer is mainly as follows.
1. The adhesive layer is softened by receiving heat during use, and is in close contact with each of the metal plate or refractory material and joint material on the outermost peripheral surface of the interior body.
2. Similarly, the contact area increases by biting into these irregularities,
3. Mechanical entanglement or frictional resistance increases,
4). The interior body and the adhesive layer receive heat, causing sintering, reaction (generation of the third substance), etc. between the adhesive layer and the metal plate or refractory on the outermost peripheral surface of the interior body, and the joint material. Form or increase the bonding state.

When the outermost peripheral surface of the interior body is refractory, the chemical composition of the refractory and the chemical composition of the adhesive layer, the chemical composition of the adhesive layer and the chemical composition of the joint material, etc., change during heat reception when they are mixed May be adjusted from the state diagram or the like so as to reduce melting or generate minerals.
At the time of removing the interior body, these temperatures become a state in which these low-melting materials are solidified or minerals are stabilized, so that an adhesive force is generated or an adhesive force is increased.
For example, in the case of a general refractory composition such as refractory on the outermost surface of the interior body and alumina, alumina-silica, spinel, or zircon in the joint material, silicate, alkali metal oxide, alkaline earth An adhesive layer containing a metal oxide or the like may be used.

If the outermost peripheral surface of the interior body is a metal plate, further change in the metal structure or surface of the metal plate, such as metal that oxidizes or corrodes the metal grain boundaries or surface, or is fused at high temperature in the adhesive layer. By including the component to be generated, the adhesive force with the adhesive layer can be enhanced. Examples of these components include phosphorus, sulfur, etc., iron, iron-based alloys, and the like.
Also in this case, when the interior body is removed, these temperatures are solidified or stabilized, so that an adhesive force is generated or an adhesive force is increased.

  In the following, the case of using an adhesive layer containing a silicate derived from water glass and using a metal plate and an alumina-silica castable refractory as the outermost peripheral surface of the interior body will be described as an example. A form is demonstrated.

  Water glass is not only refractory, but also metal plate that is harder to apply than refractory, so that it can retain its shape (so-called “non-flowing property”) during installation work such as wettability, spreadability, and coating. It has a viscosity of

Water glass is represented by R ₂ O.nSiO ₂ .mH ₂ O as a general molecular formula, R represents an alkali metal such as Na, K, Li, etc., and the coefficient n represents the number of moles of SiO ₂ . Industrially, those having n in the range of 0.5 to 4.2 are produced, and those having n of about 2 to 4 are generally used. m represents the number of moles of H ₂ O, and those in the range of about 2.0 to 3.5 are commercially available.

This water glass has a SiO ₂ / R ₂ O (R: alkali metal) molar ratio of No. 2 water glass (viscosity of about 200 mPa · s) or No. 3 water glass (viscosity of about 2). Most preferably, 80 mPa · s) is used.
The chemical components after heat treatment at 1050 ° C. according to JIS R 2212-1-5 of this water glass No. ₂ are SiO ₂ 51 mass% to 61 mass% and alkali metal oxide 17 mass% to 25 mass%. It is below mass%.

At the time of application to the outermost peripheral surface of the interior body, the interior body is generally frustoconical, so regardless of the direction in which it is placed, one of the surfaces will be in a downward direction, that is, a direction that is lowered by gravity. For this reason, water glass must have shape retention that does not flow down during coating.
Further, in order to install water glass thinly on the entire outermost peripheral surface of the interior body by coating or the like, it is also preferable that the viscosity is not too low and not too high because the extensibility is also necessary.
Mainly for these reasons, the water glass is preferably No. 2 or No. 3.

  Next, a method for manufacturing the interior body will be described. For example, No. 2 water glass (viscosity of about 200 mPa · s) is applied to the entire outermost peripheral surface of the truncated cone-shaped interior body by a method such as brushing, spraying, or dipping. Apply at a thickness of 5 to 2 mm.

The thickness of the adhesive layer depends on whether it adheres to the joint material, and reacts with the joint material and the outermost peripheral surface of the interior body (especially in the case of a refractory) to be integrated or absorbed into the pores. Considering the change, about 0.5 mm or more and about 2 mm or less are preferable.
The degree of this change varies depending on the chemical composition of the adhesive layer itself, the chemical composition of the joint material and the outermost peripheral surface of the interior body, the particle composition, the physical properties such as the porosity, and the like. What is necessary is just to optimize thickness suitably.

In addition to the No. 2 water glass, water glass with different SiO ₂ / R ₂ O ratios (No. 1, No. 3, No. 4) and R can be used as the basic part of the silicate-containing adhesive layer. In addition to Na, K and Li can also be used. In addition to water glass, powdered alkali silicate can be dissolved in water.
In order to enhance the function of improving the viscosity, shape retention, etc., various organic substances such as dextrin and cellulose, various clays, inorganic or organic fibers, etc. can be added to the material of these adhesive layers.

  After the adhesive layer is installed, the film is cured for about one day or naturally dried, and then heat treatment is performed at a temperature of 100 ° C. or higher, preferably 300 ° C. or higher with a dryer. By this heat treatment, the water glass layer (adhesive layer) is strengthened.

In order to improve the strength of this layer, a commonly used alkali silicate curing agent, for example, an oxide or a hydroxide containing components such as Mg and Ca can be added to the adhesive layer.
Furthermore, in order to improve the shape retention property, spreadability improvement, strength improvement, fire resistance, corrosion resistance, etc. at the time of installation of this layer, this adhesive layer has a size not more than the thickness of the adhesive layer to be set, preferably Refractory raw material particles having a size (particle size) of 0.5 mm or less can be contained. In order to maintain or ensure the spreadability and the like, the size (particle size) of the refractory raw material particles is more preferably about 0.2 mm or less. Or, in order to reinforce the contact surface with the joint material, a rough structure may be used so as to form some irregularities on the surface.

  These refractory raw material particles contribute to the sintering and reaction between the particles, the main constituent material (silicate) in the adhesive layer, the refractory of the interior body, the joint material or the metal plate, etc. In order to ensure or enhance adhesion to a metal plate or the like, an oxide, metal particles, or the like is preferable.

  If the content of the refractory raw material particles increases, the spreadability and uniformity may decrease, and discontinuous parts may occur in the adhesive layer, resulting in cracks. From the viewpoint of emphasizing spreadability. Is preferably about 10% by mass or less in total in the adhesive layer.

These refractory raw material particles can contain one or a plurality of kinds regardless of whether they are artificial or natural such as sintering and electromelting. Specific examples of these raw materials include alumina based mainly on corundum, mullite, sillimanite, kaolinite and other clays / chamottes, rholite, ceramics, and other alumina-silica based, zircon based, spinel based, quartz, cristobalite. In the case of a metal such as silicic acid such as tridymite and glass, particles of iron or iron-based metal can be used.
Further, inorganic or metal fibers may be included for reinforcing the adhesive layer.

  There is no particular limitation on the type and composition of the refractory layer of the interior body and the joint material, and the composition of the adhesive layer may be selected according to what is set according to each application.

<Example>
Hereinafter, examples of embodiments of the present invention will be described by way of specific examples.

  In this embodiment, the metal plate or refractory that is the outermost peripheral surface of the interior body is a base plate that is relatively low in adhesion to the adhesive layer, and the adhesive layer is installed on the surface of the metal plate. Furthermore, a refractory layer corresponding to the joint material was placed on the surface of the adhesive layer, and the shear strength of the heat-treated sample was measured. The refractory layer has almost the same configuration as the mortar used as a joint material when the interior body is mounted on the tuyere except for the particle size configuration. Therefore, it can be presumed that the test results with the sample using this refractory layer are the same as when using actual mortar.

Specifically, the sample was produced by the following method.
A flat metal plate of 120 x 70 x 1.2 mm ^t is placed on the bottom of the metal frame, and a liquid containing refractory raw material particles on water glass is applied to the metal plate surface with a brush, and a castable refractory is 30 mm on it. Casting while vibrating to the height of. After curing for one day in this state (curing and natural drying), heat treatment was performed in an electric furnace at 1200 ° C. for 1 hour.

The castable refractory has a maximum particle size of 5 mm, a proportion of particles having a particle size of 5 to 1 mm is about 50% by mass, Al ₂ O ₃ content is about 90% by mass, CaO content is about 2% by mass, 1000 ° C. An alumina-magnesia material having an apparent porosity after heat treatment of about 16% and a bending strength of about 4 MPa after heat treatment at 1000 ° C. was used.

  The workability (coating workability to metal plate) when applying water glass was evaluated as ◯ when the spreadability was good and △ when there was some difficulty. This “slightly difficult” includes not only the difficulty of coating, which requires a force in the coating operation itself, but also the case where it is difficult to ensure uniformity in a small number of operations, that is, the case where so-called coating unevenness is likely to occur.

As described above, the adhesive layer was cast on a metal plate of 120 × 70 × 1.2 mm ^t through a water glass coating layer as an index of strength of adhesion between the castable refractory material imitating the outermost outer periphery refractory material layer. About the sample after 1200 degreeC heat processing of a castable refractory, the shear strength until a load was applied to the vertical axis direction and both peeled with an Amsler tester was measured, and this measured value was evaluated as "joining strength".

  Table 1 shows the configuration and evaluation results of each example.

Examples 1 to 8 are examples based on No. 2 water glass.
Example 1 was application | coating only by No. 2 water glass, application | coating workability | operativity was favorable, there existed the uniformity of a coating film, and the coating-film thickness was able to ensure about 1-2 mm. The bonding strength was 2.1 MPa, which was significantly improved as compared to <0.1 of Comparative Example 1 which is a conventional technique having no adhesive layer.

Examples 2 to 8 are examples in which water glass No. 2 contains oxide refractory raw material particles. The oxide refractory raw material particles used had a size that passed through a sieve having an opening of 0.212 mm.
In Examples 2 to 6 in which the content of oxide refractory raw material particles was 10% by mass or less, the bonding strength was higher than that in the case of not containing oxide refractory raw material particles (Example 1). When the content of the raw material particles exceeds 10% by mass (Examples 7 and 8), the coating workability (extensibility, etc.) on the metal plate starts to deteriorate and unevenness occurs on the coated surface, resulting in a decrease in bonding strength. It became a trend. For this reason, for Examples 7 and 8, confirmation with an actual machine (pull-out test) was not performed.

  Examples 9 to 14 are examples based on No. 3 water glass. It was the same tendency as the above-mentioned Examples 1-8 based on No. 2 water glass.

In an actual machine, a gas blowing plug attached to the tuyere using the above-mentioned refractory layer as a joint material is used, and the refractory layer remains on the tuyere side when the gas blowing plug after use is pulled out. It was confirmed whether or not the metal plate could be removed.
In contrast to Comparative Example 1 which does not have an adhesive layer, the refractory layer could not be pulled out together with the gas blowing plug (conceptually refer to FIG. 3), but it was not used for confirmation with an actual machine. Except for Examples 7, 8, 13, and 14, all of the examples were able to pull out the refractory layer together with the gas blowing plug (conceptually refer to FIG. 2).

1 Interior body 2 Metal plate (metal case)
3 Adhesive layer 4 Dense refractory layer 5 Sealing material 6 Breathable refractory layer 7 Gas introduction pipe 8 Tuyere 9 Joint material

Claims (9)

  An interior body fitted and attached to a tuyere of a molten metal container, wherein the joint material and the outermost peripheral surface of the interior body are in contact with at least the inner hole surface of the tuyere through the joint material. An interior body provided with a layer having a function of adhering (hereinafter referred to as “adhesive layer”).   The interior body according to claim 1, wherein the adhesive layer contains one or more selected from silicate, phosphorus, sulfur, alkali metal oxide, or alkaline earth metal oxide.   The interior body according to claim 2, wherein the silicate is derived from water glass.   The adhesive layer has a total of 10 masses of refractory raw material particles or metal particles of at least one kind of alumina, alumina-silica, zircon, spinel or silicic acid having a particle size of 0.5 mm or less. The interior body according to any one of claims 1 to 3, which is contained in an amount of not more than%.   The interior body according to claim 4, wherein the metal particles are iron or iron-based alloy particles.   The interior body according to any one of claims 1 to 5, wherein a maximum thickness of the adhesive layer is 0.5 mm or more and 2 mm or less.   It is a manufacturing method of the interior body in any one of Claims 1-6, Comprising: On the outermost peripheral surface of the said interior body, an adhesive layer is formed with the material containing a silicate, After formation of the said adhesive layer A method for manufacturing an interior body, including a step of heat treatment at 100 ° C or higher.   The method for manufacturing an interior body according to claim 7, wherein the material containing the silicate is water glass. The water _glass, SiO _{2 /} R ₂ O: molar ratio of (R alkali metal) is 2.35 or more 3.35 or less, the production method of the inner body according to claim 8.

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