JPH03118954A - Plate brick for sliding nozzle - Google Patents

Abstract

PURPOSE:To obtain a plate brick having excellent spalling resistance, corrosion resistance and oxidizing resistance and sufficient mechanical strength by spreading silicone resin on upper part of raw refractory material with refractory inorganic material and phenol resin mixed at the specific ratios, respectively, at the time of forming. CONSTITUTION:To 100wt. parts of the material in which one or more kinds of the refractory materials are blended adjusting the grain sizes, 1-15wt. parts of thermosetting phenol resin is added and kneaded. This kneaded raw refractory material is packed in the metallic mold and the silicone resin is spread on this, and after forming under pressurizing, the heat treatment is executed. The first layer 1 is the layer constituted with the kneaded material using the phenol resin as binder and the second layer is constituted with the raw refractory material spread with the silicone resin at position corresponding to sliding face. By this method, the SN brick is economically imparted with the oxidizing resistance on the sliding face and improved in durability without any adverse influence on slidability, corrosion resistance and spalling resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plate brick for a sliding nozzle used for controlling the flow rate of molten steel in continuous molten steel casting equipment.

[Conventional technology]

Sliding nozzles (hereinafter abbreviated as SN) are an extremely useful means of controlling the flow rate of molten metal.Especially in the steel industry, they are widely used to control the flow rates of hot metal and molten steel, and recently the conditions for their use have become increasingly severe. ing. The SN device is roughly divided into three parts: an upper nozzle, a plate brick consisting of fixed and sliding plates, and a lower nozzle. Among these, the plate brick is the most important because it controls the flow rate of molten metal. This is a part that requires advanced functionality. Plate bricks are subject to physical and chemical erosion due to rapid thermal shock and abrasion caused by molten metal flow, so they are required to have excellent spalling resistance and corrosion resistance. Furthermore, in order to obtain stable and high durability, it is also required to have sufficient mechanical strength and excellent oxidation resistance. Therefore, for example, an SN using a combination of a thermosetting resin such as a phenolic resin and a silicone resin as described in JP-A-1-103952,
Among the plate bricks, SN plate bricks with sufficient mechanical strength and oxidation resistance are disclosed.

[The problem that inventions try to solve]

However, refractories containing phenolic resin have a temperature of 300°
At temperatures above C, the strength decreases significantly due to oxidation.On the other hand, refractories containing silicone resin have excellent oxidation resistance among thermosetting resins, but the high price of silicone resin limits the amount of use. There was a problem with being exposed.

As a recent trend in refractories for SN, reducing the cost of refractories is also an important issue, and blending a large amount of silicone resin increases manufacturing costs, which is not preferable.

In view of the above-mentioned conventional circumstances, an object of the present invention is to provide an SN plate brick that has excellent spalling resistance, corrosion resistance, oxidation resistance, and sufficient mechanical strength, and further reduces manufacturing costs. do.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a sliding nozzle in which silicone resin is sprayed on the upper part of the clay at the time of molding, using a clay mixture of 100 parts by weight of a fire-resistant inorganic material and 1 to 15 parts by weight of a phenolic resin. It provides plate bricks.

[For production]

As a result of intensive research on SN plate bricks, the present inventors have found that damage due to oxidation during use gradually spreads and progresses from the sliding surface that comes into direct contact with molten steel into the inside of the plate brick. Therefore, by spraying silicone resin onto the sliding surface of the clay filled in the mold, it is possible to economically add oxidation resistance to the sliding surface of plate bricks by reducing the amount of silicone resin added. can.

As the refractory material used in the present invention, any material can be used from among alumina, silica, aluminosilicate, magnesia, spinel, carbide, nitride, carbonaceous materials, metals or alloys such as aluminum, silicon, and magnesium. .

1 to 15 parts by weight of a thermosetting phenol resin is added to 100 parts by weight of a mixture of one or more of the above fire-resistant materials with particle sizes adjusted and kneaded. If the amount of the phenol resin added is less than 1 part by weight, the strength of the molded product will not be sufficient, and if it is more than 15 parts by weight, lamination will occur in the molded product and molding will not be possible.

The kneaded clay is filled into a mold, silicone resin is further spread on the upper part of the clay, pressure molded, and then heat treated at a temperature of 1000° C. or less. Heat treatment is usually carried out at 100-300°C, but if the strength of the brick is required, the temperature is 500-100°C in order to melt the low melting point metal or react with other materials.
Heat treatment is performed at a temperature of 0° C. in a non-oxidizing atmosphere. The treatment temperature is preferably 1000° C. or lower; if it is 1000° C. or higher, the spalling resistance of the SN plate will deteriorate.

〔Example〕

The present invention will be specifically explained with reference to Examples.

A particle size blend of 95% sintered alumina, 3% clay, and 2% carbon powder was kneaded using 5% phenolic resin as a binder. The kneaded material was filled into a mold, silicone resin (liquid) was sprinkled on top of the mold, and after molding, heat treatment was performed at a temperature of 180°C.

It goes without saying that the silicone resin can be used in either liquid or powder form.

The product of the present invention will be explained based on FIG. The first layer 1 is a layer made of a kneaded material using a phenol resin as a binder, and the second layer 2 is made of clay with silicone resin dispersed on the sliding surface.

When the product of the present invention was used as a molten steel flow rate control stopper in a continuous casting facility using a conventional A1203-C SN plate brick using only phenol resin as a binder as a comparative material, the sliding surface of the conventional product was decarburized. In contrast, the product of the present invention had so-called surface roughness and became unusable after using 5 channels, whereas the product of the present invention had only slight surface roughness, inner hole edge damage, and cracks, and could be used for an additional 5 channels, for a total of 10 channels.

〔Effect of the invention〕

The SN plate brick according to the present invention has sliding properties, corrosion resistance,
Without adversely affecting spalling resistance, and
It becomes possible to economically impart oxidation resistance to the sliding surface, thereby improving durability.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention. A schematic sectional view showing an embodiment of the present invention Condolence

Claims (1)

[Claims] (1) 100 parts by weight of fire-resistant inorganic material and 1 part of phenolic resin
A plate brick for a sliding nozzle, characterized in that silicone resin is sprinkled on the upper part of the clay mixed with ~15 parts by weight during molding.