JPH10194851A - Spray coating material for tundish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spray coating material for a tundish excellent in slaking resistance and usable by using water. SOLUTION: A spray coating material for a tundish contg. aggregate, a binder and a viscosity imparting material such as clay is blended with 10-80wt.% iron bonded magnesia-lime aggregate contg., 5-20wt.% CaO and 1-6wt.% Fe2 O3 . Powdery sodium silicate is used as the binder by 0.5-5wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray coating material for a tundish used for coating the surface of a tundish lining base material.

[0002]

2. Description of the Related Art Conventionally, as a coating material for lining of a tundish for continuous casting, a spray coating material using a magnesia-based aggregate has been widely used. In addition, a spray coating material using a lime-based aggregate has been widely used. Coating materials are used.

[0003] The coating material for lining tundish using lime-based aggregate is calcareous (CaO).
Metallurgy effect by absorbing alumina and other impurities that become non-metallic inclusions in molten steel (cleaning effect of steel)
This has the advantage of producing

[0004]

However, among coating materials using lime-based aggregates, for example, in a conventional spray coating material for tundish using dolomite, cracks occur in the construction body due to digestion of the aggregates. However, there is a problem that peeling occurs, and it is difficult to use. Further, in a coating material using dolomite, water cannot be used due to digestibility of dolomite or the like, and there is a problem that the method of use is limited to non-aqueous use.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a spray coating material for a tundish which has excellent digestion resistance and can be used with water.

[0006]

In order to achieve the above object, a spray coating material for a tundish of the present invention is provided for a tundish containing an aggregate, a binder, and a viscosity-imparting material such as clay. In spray coating materials, C
An iron-bonded magnesia-lime aggregate containing 5 to 20% by weight of aO and 1 to 6% by weight of Fe2 O3 is used.
It is characterized by being blended at a ratio of 0% by weight.

[0007] Further, the present invention is characterized in that powdered sodium silicate is blended in a ratio of 0.5 to 5% by weight as a binder.

[0008] As described above, the spray coating material for tundish of the present invention mainly comprises an aggregate, a binder and a viscosity-imparting material.
An iron-bonded magnesia-lime aggregate containing 20% by weight and Fe2O3 at a ratio of 1 to 6% by weight is used at a ratio of 10 to 80% by weight.

In the coating material of the present invention, the iron-bonded magnesia-lime aggregate is used at a ratio of 10 to 80% by weight because the content of the iron-bonded magnesia-lime aggregate is less than 10% by weight. Then, the metallurgical effect (washing effect of the steel) by adsorbing the alumina content and other non-metallic inclusions in the molten steel is not sufficiently exhibited, and when it exceeds 80% by weight, the molten slag penetrates.
The seizure phenomenon of the tundish with the base material occurs, and the base material is damaged.

The reason why CaO is contained at a ratio of 5 to 20% by weight with respect to the iron-bonded magnesia-lime aggregate is that when the content of CaO is less than 5% by weight, the spray coating for tundish is performed. When used as a material, the metallurgical effect (steel cleaning effect) by adsorbing the alumina and other non-metallic inclusions in the molten steel is not sufficiently exhibited, and the CaO content is 20% by weight. %, The digestion resistance is undesirably reduced.

In addition, the reason why Fe2O3 is contained at a ratio of 1 to 6% by weight with respect to the iron-bonded magnesia-lime aggregate is that when the content of Fe2O3 is less than 1% by weight, the magnesia-lime aggregate is reduced. When the content of Fe2O3 exceeds 6% by weight, the corrosion resistance to molten steel or molten slag decreases when used as a spray coating material for tundish. And no longer serves as a coating material.

In addition to the above-mentioned iron-bonded magnesia-lime aggregate, seawater magnesia or natural magnesia can be blended as an aggregate. Further, as the viscosity-imparting material, various materials generally used can be used, and specifically, clay, bentonite, and the like are used.

Further, in the spray coating material for tundish of the present invention, it is preferable to use powdered sodium silicate as a binder and to mix it in a ratio of 0.5 to 5% by weight. When the content of the powdered sodium silicate is less than 0.5% by weight, during curing or drying after the construction, the digestion resistance of the magnesia-lime aggregate is reduced and the construction body is peeled off due to insufficient strength, and If the content of the powdered sodium silicate exceeds 5% by weight, when used as a spray coating material for tundish, the corrosion resistance to molten steel or molten slag decreases,
It is not preferable because it sticks to the tundish base material and damages the base material.

As the binder, it is also possible to combine sodium phosphate in addition to the above-mentioned powdered sodium silicate. In general, slaked lime, sodium silicate fluoride, phosphate glass and the like can be added as a curing aid. Further, in the spray coating material of the present invention, it is also possible to add an organic fiber or the like for the purpose of lowering the bulk specific gravity of the material and preventing explosion.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be shown and features thereof will be described in more detail. Spray coating materials (Examples 1 to 4) having compositions as shown in Table 1 were prepared as examples of the spray coating material for tundish of the present invention.

As a comparative example, as shown in Table 1, a spray coating material not using powdered sodium silicate as a binder (Comparative Example 1), and an iron-bonded magnesia-lime aggregate as an aggregate were not used. A spray coating material (Comparative Example 2) using magnesia aggregate was prepared.

[0017]

[Table 1]

Each of the spray coating materials of Examples 1 to 4 and Comparative Examples 1 and 2 in Table 1 is lined on a tundish, and after spraying, whether or not the construction body is digested (cracks or peeling occurs in the construction body) Or not) and observe
The thickness of the deposits in the tundish nozzle after four charge casting from the molten steel ladle was measured. The results are shown in Table 1.

In the spray coating materials of Examples 1 to 3, cracks and peeling did not occur in the sprayed product, and no digestion was observed. Further, in Example 3 in which the content of the iron-bonded magnesia-lime aggregate was increased, it was confirmed that the thickness of the deposit in the tundish nozzle after use was reduced.

In the spray coating material of Example 4, digestion (cracking and peeling) of the sprayed construction was not recognized, though the content of sodium silicate was small. In addition, the thickness of the deposit in the tundish nozzle after use was small, and good results were obtained in this respect as well.

On the other hand, in the spray coating material of Comparative Example 1 in which powdered sodium silicate was not used as the binder, digestion (cracking and peeling) was observed in the sprayed product. In addition, in the spray coating material of Comparative Example 2 using the conventional magnesia aggregate without using the iron-bonded magnesia-lime aggregate as the aggregate, digestion (the occurrence of cracks and peeling in the construction body) was not observed. However, the thickness of deposits (non-metallic inclusions mainly composed of alumina) in the tundish nozzle after use was large.

As a result, it can be confirmed that the spray coating materials of Examples 1 to 4 are excellent in digestion resistance and can reduce the amount of deposits on the tundish nozzle as compared with the conventional spray coating material. Was.

The present invention is not limited to the above-described embodiment, but relates to the mixing ratio of the aggregate, the type of the binder, the presence or absence and the amount of other trace additives, and the like, within the scope of the invention. Various applications and modifications are possible.

[0024]

The spray coating material for tundish of the present invention comprises 5 to 20% by weight of CaO and 1% of Fe2 O3.
Because iron-bonded magnesia-lime aggregate containing at a ratio of ~ 6 wt% is blended at a ratio of 10-80 wt%
Water can be used, and a coating material having excellent digestion resistance can be obtained.

Further, since the lime-based aggregate is used, the amount of deposits (non-metallic inclusions mainly composed of alumina) that block the tundish nozzle can be reduced by using a conventional magnesia-based aggregate. It can be significantly reduced as compared with the applied coating material.

Further, by blending powdery sodium silicate as a binder at a ratio of 0.5 to 5% by weight, it becomes possible to improve the mechanical strength of the construction body, thereby making the present invention more effective. be able to.

Claims (2)

[Claims] 1. A spray coating material for a tundish containing an aggregate, a binder, and a viscosity-imparting material such as clay, wherein the content of CaO is 5 to 20% by weight and the content of Fe2 O3 is 1 to 6% by weight. Containing iron bond magnesia lime aggregate 10 ~
A spray coating material for a tundish, which is blended at a ratio of 80% by weight. 2. A powdery sodium silicate is used as a binder.
The spray coating material for a tundish according to claim 1, wherein the spray coating material is blended at a ratio of 5 to 5% by weight.