JPS6047230B2 - How to repair sliding nozzle plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding nozzle for molten steel, and more particularly, to a method for repairing a sliding plate (hereinafter simply referred to as a plate) in the sliding nozzle.

As is well known, a sliding nozzle is attached to a pot, tundish, etc. for storing molten steel, and performs operations such as flowing out, stopping, or controlling the amount of outflow of molten steel.

FIG. 1 is a cross-sectional structural diagram showing a well-known general sliding nozzle.

In the figure, the sliding nozzle is attached to the bottom iron shell 1a of a pot, tundish, etc. (hereinafter simply referred to as pot 1).
an upper nozzle holding hardware 2 connected to the holding hardware 2, an upper plate 3 held by the holding hardware 2, an upper nozzle 4 fitted to the pot nozzle brick lb, a lower plate 5 sliding in contact with the lower surface of the upper plate; The lower sliding metal fitting 7 integrally surrounds the lower nozzle 6. The lower sliding hardware 7 is connected to a drive device 9 such as a cylinder device via a link mechanism 8, and moves forward and backward by driving the drive device 9 to open and close the nozzle hole 10. By the way, the upper plate 3 and the lower plate 5 (the upper plate 3 and the lower plate 5 are collectively referred to as the plate 30 hereinafter).

) were severely damaged by the outflow of molten steel and mutual contact and sliding, and their lives were extremely short. The present invention enables reuse of the damaged plate 30 by providing a repair method for effectively repairing the damaged plate 30,
The purpose is to significantly extend the life of the plate 30.

Hereinafter, the present invention will be explained in detail based on Examples. Now, the second
The figure is a perspective view of the damaged plate 30, where "a" indicates a crack that occurred on the sliding surface 30a of the plate 30, and "a" indicates a flaw caused by melting. When the damage occurs to the plate 30, the fluorate 30 is removed from the pan 1 and allowed to cool naturally to about room temperature. Next, a refractory sliding surface filler (hereinafter simply referred to as fireproof filler), which is referred to in the present invention, is applied to the damaged portion of the sliding surface of the plate 30. By the way, the present inventors have repeatedly conducted various experimental studies on refractory materials to be used for collecting the plate sliding surface 30a, which is subjected to severe usage conditions such as contacting high-temperature molten steel and sliding under high contact pressure. As a result, we obtained the following new findings. That is, it has been confirmed that a refractory material made by mixing high alumina refractory, sodium silicate, and graphite lubricant in an optimal ratio exhibits excellent durability even under the above-mentioned severe conditions. The higher the content of alumina (Al2O3) is, the more preferable it is for high alumina refractory materials, but in the experience of the present inventors, if the material contains 50% or more of alumina, for example, silica, iron oxide, etc. can be added to it. It is possible to use them in combination8. A small amount of asbestos, fireclay, iron oxide, surfactant, etc. may be mixed into the sodium silicate. As the graphite lubricant, for example, one obtained by kneading graphite with a binder made of an expandable organic solution and water may be used. Now, Table 1 shows the results of using a mixture of the above-mentioned high alumina refractory material, sodium silicate, and graphite lubricant in various proportions.

As can be seen from Table 1, high alumina refractory materials 50 to 6
It has been confirmed that if the sodium silicate and graphite lubricant are each in the range of 20 to 30% compared to 0%, it is sufficient to function as the fireproof repair material of the present invention.

Then, the fireproof repair material is applied to the damaged part of the plate sliding surface 30a, and once it dries, the cracks a and the flaws b can be repaired, and the plate 30 can be reused. . In addition, after applying the fireproof repair material and letting it dry,
Furthermore, if graphite lubricant is applied alone to the entire sliding surface,
This is effective in preventing burn-in during operation. As detailed above, the present invention has developed a fire-resistant repair material that can be used under severe conditions, and by applying the fire-resistant repair material to the damaged sliding surface of the plate 30 and drying it, the plate 30 can be repaired. Conventionally, products that could be reliably repaired had a service life of about 5 times at most, but by repairing and reusing them with the present invention, it is now possible to significantly extend the service life to 8 to 1 year old. Along with this, the furnace material consumption rate for pot 1 also decreased significantly.

As described above, the practical effects of the present invention are very large. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional structural view showing a known general sliding nozzle, and FIG. 2 is a perspective view showing a damaged plate.

1... Pot, 2... Holding hardware, 3...
...Top plate, 4...Top nozzle, 5.
...Lower plate, 6...Lower nozzle, 7...
...Lower sliding hardware, 8...Link mechanism, 9
... Drive device, 10 ... Nozzle hole, 3
0...Plate.

Claims (1)

[Claims] 1 After removal and cooling, 50-60% (wt%) high alumina refractory material and 20-30% (wt%) sodium silicate and graphite are applied to the damaged part of the sliding plate of the sliding nozzle for molten steel. A sliding nozzle plate repair method characterized by applying a refractory sliding surface repair material mixed with a quality lubricant and drying it.