JPH0890170A - Side dam plate for strip casting - Google Patents

Abstract

PURPOSE: To provide a side dam plate blank which is extremely little in erosion, penetration and spalling by molten metal and is low in cost for a side dam plate for strip casting of steels, stainless steels, etc. CONSTITUTION: The side dam plate for strip casting of steels, stainless steels, etc., is formed of a material of which the constituting components are SIALON /BN base. The Z value in the chemical formula Si6 -zAlzOzN-z of the SIALON is 2.0 to 4.0. The content of the BN is 0.5 to 50wt.%. The side dam plate consisting of such SIALON/BN is little in the erosion and penetration to be incurred by the steels, stainless steels, etc., and, therefore, the longer life of the side dam plate is obtd. and the production of the steels, stainless steels, etc., at a lower cost is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side dam plate for strip casting of strip casting which is a method for continuously casting thin plates of steel, stainless steel or the like.

[0002]

2. Description of the Related Art A side dam plate is required for strip casting of steel, stainless steel or the like, and the side dam plate is desired to have high corrosion resistance and long life for steel, stainless steel or the like. Conventionally, a material such as silicon nitride or BN is used as the material of the side dam plate, but it has caused a problem depending on the use conditions. Generally, silicon nitride or BN is used, but silicon nitride is strong in melting loss / penetration but weak in spalling, so it is easily cracked in heating / cooling cycles. On the other hand, the BN quality is strong against spalling, but the price is so high that it is difficult to use economically.

[0003]

Provided is a side dam plate material, such as steel, stainless steel, etc., for strip casting, which is easily priced when the melting loss, permeation and spalling with respect to the molten metal are extremely small.

[0004]

[Means for Solving the Problems] Side dam plates for strip casting of steel, stainless steel, etc.,
It is made of a material whose constituents are SIALON / BN quality. SIALON is Z value in the chemical formula Si ₆ _zAlzOzN ₈ _z is 2.0 to 4.0. BN is 0.5-5
0% by weight.

[0005]

Operation: SIALON / BN side dam plates are used for strip casting. The side dam plate according to the present invention will be described in detail below. Component is SI
ALON / BN quality, SIALON is β'type, and Z value in its chemical formula Si ₆ _zAlzOzN ₈ _z is 2.0-
The content of 4.0 and BN is 0.5 to 50% by weight.

The production method is raw material adjustment → molding → drying and degreasing → processing → sintering. The starting raw material is adjusted to finally have the above-mentioned constituents through firing. That is, when atmospheric pressure sintering is used, Si ₃ N ₄ , AlN, and Al ₂ O ₃ powders are mixed so that the Z value is 2.0 to 4.0, and the sintering aid, binder, and BN powder are mixed. Is mixed with a non-aqueous solvent such as acetone for 12 to 24 hours in a tromill, and spray granulated for molding.

When reactive sintering is used, Si, A
1 and Al ₂ O ₃ powders each had a Z value of 2.0 after the nitriding reaction.
The mixture is blended so as to be about 4.0, and the binder and BN powder are added in a predetermined amount, and the mixture is mixed with a nonaqueous solvent such as acetone for 12 to 24 hours, spray-granulated, and subjected to molding.

Here, the Z value is set to 2.0 to 4.0 because
If it is less than 2.0, the solid solution amount of Al ₂ O ₃ is small, so Si
_{This is} because the properties of ₃ N ₄ become closer to that of N ₄ itself, and the corrosion resistance and oxidation resistance become insufficient. On the other hand, when Z exceeds 4.0, the corrosion resistance and the like improve, but the thermal shock resistance and strength decrease. Because it is. Further, the BN amount was set to 0.5 to 50% by weight, but if it exceeds 50%, the tendency of BN to hinder the production and sintering of SIALON is too strong, the strength is remarkably lowered, and it tends to be a problem in practical use. .

The molding is usually carried out by a uniaxial molding method or a hydrostatic molding method, but in some cases it is also possible to carry out strip casting without granulating the raw material. The molded body is dried and volatilized to remove binders (degreasing), and then processed and sintered. In the case of pressureless sintering, 16
The storage time is preferably 50 to 1800 ° C. and the storage time is 5 to 10 hours. The higher the temperature, the shorter the holding time should be. In the case of reaction sintering, it is performed at 1400 to 1600 ° C. in a nitrogen atmosphere, and the holding time is preferably 5 to 10 hours, although it depends on the shape.

[0010]

EXAMPLES Next, examples will be described. SIALON / B
As the N quality, the amount of BN was 30% by weight, and the Z value in the chemical formula Si ₆ _zAlzOzN ₈ _z of SIALON was calculated to be 1.0.
˜5.0, and a SALON Z value of 3.0 and a BN amount of 0 to 60% by weight were prepared. Next, each test piece cut out into a size of □ 20 × 250 mm was immersed in steel melted at 1700 ° C. for 30 minutes, and the melting loss amount, metal permeation amount, and oxidation loss amount were measured. The results are shown in Tables 1 and 2.

[0011]

[Table 1]

[0012]

[Table 2]

Next, SIALON / BN quality (Z = 3.0,
A □ 20 × 2500 mm specimen was prepared with BN = 30% by weight) and an immersion test in steel was performed. As a condition, 20
The operation of melting kg of steel in a molten metal furnace and holding it at 1700 ° C., stirring the test body while immersing it in the molten metal for 5 minutes, removing from the molten metal and allowing to cool is repeated 10 times at maximum. Similar tests were conducted on silicon nitride and BN quality test pieces as comparative materials.
Table 3 shows the results.

[0014]

[Table 3]

The side dam plate of the present invention does not break even after repeating 10 times, and the amount of melting loss, permeation and oxidation is extremely small. Although there was little melting loss and permeation into the silicon nitride of the comparative product, it was broken at the fourth time due to thermal shock. Although erosion / penetration and oxidation of BN material are smaller than SIALON / BN material, they are still incompatible in terms of price.

[0016]

The SIA of the present invention is similar to the results of the above embodiment.
The side dam plate of LON / BN suffers less melting loss and penetration from steel, stainless steel, etc., so that the life of the side dam plate can be extended and the manufacturing cost of steel, stainless steel, etc. can be reduced.

Claims (3)

[Claims] 1. A side dam plate for strip casting of strip casting, which is a method for continuously casting thin plates of steel, stainless steel, etc., wherein the constituent component is S.
Side dam plate for strip casting characterized by IALON / BN quality. 2. The SIALON has a chemical formula of Si ₆ _zAl.
The side dam plate for strip casting according to claim 1, wherein a Z value in zOzN ₈ — z is 2.0 to 4.0. 3. The side dam plate for strip casting according to claim 1, wherein the BN is 0.5 to 50% by weight.