JPS5836986A - Manufacture of highly refractory flame spray layer coating refractories - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a refractory in which a thermally sprayed coating layer with high adhesive strength and less peeling is formed on the surface of a base brick.

Conventionally, in order to improve the heat resistance, abrasion resistance, corrosion resistance, etc. of refractories, plasma spraying of a refractory material onto the surface of a large refractory object to form a coating layer has been described, for example, in JP-A-50-555.
39, Japanese Patent Application Publication No. 55-158877, it is known that in conventional coatings, there is almost no chemical bond between the coating layer and the base brick, so the adhesive strength between the base brick and the refractory material is low. Because the adhesive strength between the coated part and the base brick is not sufficient, the coating layer is likely to peel off due to slight mechanical impact or sudden temperature changes during coating formation or use, and the original performance of thermal spraying is lost. I am fully demonstrating my abilities.
Ino is the reality.

The above-mentioned Japanese Patent Application Laid-Open No. 50-55559 K discloses an alumina-graphite immersion nozzle in which a welding layer is formed on the surface of a refractory and a method for manufacturing the same, and the spraying distance is adjusted to increase the strength of the welding between the surface of the refractory and the sprayed material. is 50~SoOgm,
The spraying angle should be 4 degrees or less with respect to the vertical plane, and the thickness of the coating layer should be 5 degrees to prevent peeling of the coating layer. Measures are being taken to keep the temperature below Dsm+.

Furthermore, JP-A-55-158877 K discloses a sliding nozzle plate brick in which a refractory material is thermally sprayed on the inner surface of a molten metal passage hole and on the sliding surface around the hole, and the plate brick has a thermal expansion coefficient that is not much different from that of the base material brick. By thermal spraying a refractory material with no difference, it is possible to prevent the peeling of the base material brick and the refractory material, but these are simply sprayed refractory materials, and as in the present invention, the base material brick and the refractory material are not separated. No measures have been taken to actively improve the adhesive strength by modifying the reactivity of the sprayed material or the surface treatment of the base brick.

The object of the present invention is to spray a highly refractory material using a water plasma spraying device onto the surface of refractories used in locations subject to wear and erosion by molten metals, slag, and molten oxides of glass. High adhesive strength, less likely to peel off,
The objective is to easily form a thick, highly refractory thermal spray coating layer.

In the water plasma spraying method, the arc generated between the cathode and anode is stabilized with water, and a refractory material is supplied into the generated high-temperature, high-speed plasma flame, which melts and collides with the surface of the base brick at high speed. Let it be strong and there. Conventionally, in the case of gas plasma spraying, which is widely used, nails, H
In contrast to the use of expensive gases such as e, water plasma spraying is economical because it uses inexpensive water.1 Furthermore, compared to gas plasma spraying, the electrical output can be set higher, resulting in higher thermal spraying efficiency. The thermal spraying capacity is 10 times higher than that of gas plasma spraying.

The present inventors have discovered that by using water plasma spraying, which has a large thermal spraying capacity, it is possible to thicken the sprayed coating layer in a short period of time, and the temperature of the sprayed coating layer is less likely to drop due to the grain, so there is less thermal stress. Therefore, it is difficult to peel off the coating layer, and during simultaneous l/cWI spraying, a chemical reaction may occur on both the base brick and the highly refractory thermally sprayed coating layer. Various studies were conducted based on the technical idea that if thermal spraying was performed by creating irregularities on the surface of the base brick to increase the adhesive strength, it would be possible to form a thermal spray coating layer with high adhesive strength and less peeling. As a result, the present invention has been completed. Namely.

In the present invention, first, a refractory material that easily reacts with the base brick is sprayed or coated on the surface of the base brick as an intermediate refractory layer, and then
Next, a coating refractory material with higher refractory properties is sprayed onto the surface of the base brick using a water plasma spraying device to form a highly refractory sprayed coating layer, thereby producing a sprayed layer-coated refractory with high fire resistance and high adhesive strength. It concerns the method of making fists.

The present invention will be specifically explained below.

As the base material or brick applied to the present invention, acidic, neutral, or basic general refractories can be used. In addition, examples of fire-resistant materials used for the highly fire-resistant thermal spray coating layer include Al
=o3%'A1. os 8101, Zr01
, Zr01-5LOB , BiLgO-Cr2O2, M
g0-A1. o, oxides such as MgO or mixtures thereof, or combinations of ZrC, 5J-C, B4C & any carbide, Si, BN4, BN & any nitride or mixtures thereof with the above oxides. b.

In addition to the above-mentioned coating refractory materials, examples of refractory materials for the intermediate refractory layer that easily react with the base brick and the highly refractory sprayed coating layer include OaO-siO@-A140@-based compounds, CaO
-MgO-A011 type compounds, boric acid type compounds, and alkali-containing low melting point compounds, and these compounds are used appropriately depending on the composition of the base brick. In other words, the material may react with the base brick and a part of the composition of the highly refractory sprayed coating layer or the base brick and the highly refractory sprayed coating layer during heat treatment after thermal spraying or during use at high temperatures to produce sintering or compounds. The refractory material to be obtained or the material has a relatively low melting point, and during coating formation by thermal spraying, a melt is generated by the heat of the plasma flame, penetrating and diffusing into the base brick and the highly refractory thermal spray coating layer, resulting in a crystalline or amorphous material. If the material generates a compound,
It is not particularly limited to the above compounds. For example, if the base material brick is AlgOs, a silica-containing compound such as V limanite is suitable as a refractory material that easily reacts with AlgOs, and these compounds react with Aljlos during heat treatment after thermal spraying or during use at high temperatures. 3Al, O8,28
10, and is firmly bonded to the base brick.

A water plasma spraying device is used as the thermal spraying device.

In the method of method 1 of the present invention, first, in the case of a refractory material for the intermediate refractory layer that easily reacts with the base brick on the surface that requires durability of the base brick, for example, a base brick of Sio, -A type fOs type. is OaO-810B-A140g yarn, CaO-
Mgo-fAO, system, Al, O8-5in, system or h
After a thin layer of either a boric acid compound or an alkali-containing low-melting compound is thermally sprayed or applied, Al5os is thermally sprayed to a required thickness as a refractory material for a highly refractory thermally sprayed coating layer. When spraying or coating the intermediate layer refractory material, the appropriate coating thickness is 0.05 to t's.
Preferably it is 0.1 to 0.5 centigrade. Below 0.05 m, there is little adhesion effect due to the reaction between the base brick and the intermediate layer and between the intermediate layer and the highly refractory spray coating layer, and above 1.0 m, the intermediate refractory layer will melt when used at high temperatures. So I don't like it.

Among the compounds that are likely to react with the base brick and the highly refractory sprayed layer used as the intermediate refractory layer in the first method, compounds with a low melting point may react with the base brick part during the formation of the coating layer. It is melted and diffused into the sprayed layer to chemically and firmly bond the image area. In addition, among the above compounds, the high melting compound and compound a' may form chemical bonds as mentioned above during coating formation, but chemical bonds may occur during use at high temperatures, which is the original purpose of refractories. This results in a refractory with high adhesive strength and resistant to peeling.

Therefore, when a low melting point compound is used in the intermediate refractory layer, it is suitable for use at relatively low temperatures even though it has high refractory properties, while Kameno, which uses a high melting point compound in the intermediate refractory layer, is suitable for relatively high temperature and harsh usage conditions. There is. In the second method, in order to further increase the adhesion between the base brick and the highly refractory sprayed coating layer, stripes are applied to the surface of the base brick that requires durability, as shown in Figure 1(&)K. A groove (1) is provided or a certain i is shown in Fig. 1 (b) K.
As shown, the method of forming surface irregularities (2) on the base brick by sandblasting or the like is to perform thermal spraying to a required thickness according to the first method.

As shown in Figure 2, it is difficult to make the thermal spray coating layer (4) thicker than the base material brick (3) K in gas plasma spraying, so seven grooves (1) and unevenness (2) are provided. However, as shown in Fig. 1, in the present invention, it is possible to easily form a thick coating layer (5), so it is possible to spray grooves (1) or Even if unevenness (2) is provided, it can be sufficiently covered, so that structurally strong adhesive strength can be obtained. I! K.

As mentioned above, the intermediate refractory layer (6) is formed on the surface of the base material brick (3) to increase the chemical bonding strength with the thermal spray coating layer (FA), so the thermal spray coating layer (5) does not peel off. Furthermore, the shape of the base brick is not limited to plate or tubular sieves, and it is extremely difficult to obtain a thick coating layer with gas plasma spraying. However, with water plasma spraying, a thickness of 30 mm or more is easily possible.

The manufacturing method of the present invention will be explained in more detail with reference to Examples below.

Example va (st) Using a solid brick as a base material, V was first applied as an intermediate refractory layer on the surface of the base brick by the method of route 1 of the present invention.
Limanite (U, Os-sto, Sample J161) was obtained. Separately, the present invention road 2
By the method of
, a groove with a depth of 4 m was provided, and using a water plasma spraying device, alunite (KsO・3AllOs
・4510m・6HIO) to 0.2111. Further, alumina was sprayed thereon to obtain a sprayed material (sample A2) having a sprayed coating layer of 14.0 to 16.0 mm.

In addition, as comparative samples, three types of coating were performed using the conventional method (A3-45), and each sample was cut out from a total of five types of sprayed material and tested. The results are shown in Table 1.

As a result of the test, it is clear that samples 1 and 2) of the present invention have excellent adhesive strength, and the thermal sprayed coating layer is difficult to peel off even under thermal shock. It has been found that it has excellent durability against wear caused by.

Table 1 Kaoru 1 Heat treatment was performed at 1300° C. for 5 hours to impart adhesive strength through a chemical reaction.

Supper 2 In inventions A1 and 2, the base material brick part was broken.

-%3 1X30X100 thermal spray coating layer is 50X10
The sample (0 ms plane) was placed in an electric furnace at 1200° C., held for 15 minutes, and then forcedly air cooled and cooled down to room temperature for about 15 hours, which was repeated.

A pentagonal refractory container was prepared for each sample (the bottom was made of alumina brick), and after melting the IC104 steel in the container using an induction furnace, the inner surface of the container was melted by moving the furnace body in a circular motion. This is a test method that compares the wear of refractories by aging the molten steel flow, and shows the wear dimensions of the most worn parts. The results are the results of a 3-hour test at a molten steel temperature of 1600° C. and a furnace rotation speed of 10100 rX.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the formation of a spray coating layer of the refractory of the present invention by water plasma spraying. FIG. 2 is a sectional view showing the formation of a spray coating layer on the surface of a base brick by gas plasma spraying. (1) Grooves (2) Irregularities (3) Base material brick (4) Gas plasma sprayed coating layer (5) Water plasma sprayed coating layer (6)
Intermediate refractory layer (a) Figure 2 (b) Figure (b)

Claims (1)

[Claims] 1 It is easy to react with the tensile force when heated on the surface of the base material brick, and it is also easy to react with the highly refractory sprayed coating layer when heated - An intermediate refractory layer is formed by coating or thermal spraying, and the surface of the intermediate refractory layer is sprayed with water plasma. A highly refractory thermal spray coating layer is formed, and by heating during or after thermal spraying, a large number of grooves or irregularities are formed on the surface of the base brick and the intermediate refractory layer, and then the intermediate refractory layer is formed. A method for producing a highly refractory four-coated refractory according to claim 1, wherein a highly refractory thermally sprayed coating layer is formed with a highly refractory thermally sprayed coating layer.