JPH08333167A - Break ring for horizontal continuous casting - Google Patents

Abstract

PURPOSE: To produce a break ring for horizontally and continuously casting steel, stainless steel, etc., from an inexpensive break ring raw material extremely little in melting loss, penetration and spalling against the melted metal. CONSTITUTION: This break ring for horizontally and continuously casting steel, stainless steel, etc., is produced from a material molded from water content- controlled Sialon-BN as a composing component. This Sialon has a chemical formula: Si6 -zAlzOzN8 -z wherein the value of (z) is 0.1-2.5. The BN is used in an amount of 10-40wt.%. The water control is performed by charging 1-5wt.% of water in sprayed granules. The break ring manufactured by controlling the water content of the Sialon-BN and subsequently molding the treated Sialon-BN is little in melting loss and penetration accepted from the melted steel, stainless steel, etc. Thereby, the life of the break ring is prolonged, and the steel, the stainless steel, etc., can safely be produced at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a break ring for horizontal continuous casting of steel, stainless steel or the like.

[0002]

2. Description of the Related Art A break ring is required for horizontal continuous casting of general steel, stainless steel and the like, and it is desired that the break ring has high corrosion resistance and hardness and long life with respect to steel, stainless steel and the like. Conventionally, silicon nitride, silicon nitride-BN or BN is used as the material for the break ring, but this has caused a problem depending on the use conditions. Generally, silicon nitride or BN is used. Silicon nitride has a high resistance to melting / penetration but a weakness to spalling, and is easily cracked in a heating / cooling cycle. On the other hand, BN
The quality is strong against spalling, but the price is so high that it is difficult to use economically.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a break ring material for horizontal continuous casting of steel, stainless steel or the like, which is extremely low in melting loss, penetration and spalling with respect to molten metal and is easy to price.

[0004]

[Means for Solving the Problems] In a break ring for horizontal continuous casting of steel, stainless steel, etc., its constituent component is SIA.
The LON-BN is made of a material that is molded by adjusting the water content. SIALON has a Z value of 0.5 to 2.5 in the chemical formula Si ₆ -zAlzOzN ₈ -z. BN is 10-40
% By weight. Moisture adjustment is to add 1-5 wt% water to the spray granules.

[0005]

Operation: The material formed by adjusting the water content of SIALON-BN is used as a break ring for horizontal continuous casting.

The break ring according to the present invention will be described in detail. The component is SIALON-BN with water content adjusted, SIALON is β'type and its chemical formula
Z value in Si ₆ -zAlzOzN ₈ -z is 0.1 to 2.5
The BN content is 10 to 40% by weight, and the water content for adjusting the water content is 1 to 5% by weight.

The manufacturing method is as follows: raw material adjustment → molding → drying and degreasing → processing → sintering. The starting materials are fired and finally compounded so as to have the above-mentioned constituents. 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 0.1 to 2.5, and the sintering aid, the binder, and the BN powder are mixed. Is mixed with a non-aqueous solvent such as acetone for 12 to 24 hours in a tromil, spray-granulated, water content is adjusted, and molding is performed.

When reactive sintering is used, Si, A
1 and Al ₂ O ₃ powders each having a Z value of 0.1 after the nitriding reaction.
The mixture is blended so as to be about 2.5, and the binder and the BN powder are added in a predetermined amount, and the mixture is mixed with a non-aqueous solvent such as acetone for 12 to 24 hours, spray-granulated, and the water content is adjusted to be used for molding. Here, the Z value is set to 0.1 to 2.5 because if it is less than 0.1, the solid solution amount of Al ₂ O ₃ is small, and it becomes close to the property of Si ₃ N ₄ itself, and the corrosion resistance and the acid resistance are reduced. This is because the chemical resistance is insufficient, and when Z exceeds 2.5, the corrosion resistance and the like are improved, but the thermal shock resistance and the strength are deteriorated. The amount of BN was set to 10 to 40% by weight, but if it is less than 10%, the effect of improving thermal shock resistance cannot be obtained, and if it exceeds 40%, BN is SIAL.
This is because the tendency to hinder the generation and sintering of ON is too strong, the strength and hardness are significantly lowered, and it is likely to cause a problem in practical use. The amount of water for adjusting the water content is 1 to 5% by weight is 1
If it is less than 5%, the effect of improving the density at the time of molding cannot be obtained, and if it exceeds 5%, the density improvement is almost the same, but the oxidation of Si ₃ N ₄ , AlN and BN is promoted, which affects the final quality. That is. Usually, a uniaxial molding method or a hydrostatic molding method is used for molding. The molded body is dried and volatilized to remove binders (degreasing), and then processed and sintered. In the case of pressureless sintering, 1650 to 1800 ° C. in a nitrogen atmosphere,
The holding time is preferably 5 to 10 hours, and 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.

[0009]

EXAMPLES Next, examples will be described. SIALON-B
As the N quality, a BN amount of 30 wt% and a water amount of 2.5 wt%, a test body in which the Z value in the chemical formula Si ₆ -zAlzOzN ₈ -z of SIALON was changed from 0 to 3.0 in calculation, and SIALON The Z value was 1.5 and the water content was 2.5% by weight, and the BN amount was changed to 0 to 50% by weight to prepare a test body. Next, each of the test pieces cut out to 20 mm x 250 mm was immersed in steel melted at 1700 ° C for 10 minutes,
The amount of erosion, the amount of metal permeation, and the amount of oxidation loss were measured. Next SIA
The chemical formula of SIALON as LON-BN quality is Si ₆ -z
The Z value of AlzOzN ₈ -z was calculated to be 1.5 and the amount of BN was set to 30% by weight, and the water content was changed to 0 to 6% by weight to form a 100 × 25 mm test piece at 2.0 ton / cm ² . Then, the molding density and the SHORE hardness after sintering were measured. The results are shown in Tables 1 to 3.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

Next, SIALON-BN quality (Z = 1.5,
BN = 30 wt%, water content = 2.5 wt%) □ 20
A test piece of X250 mm was prepared and an immersion test in steel was conducted. As a condition, 20 kg of steel is melted in an induction furnace and 170
The operation of holding at 0 ° C., stirring the test body while immersing it in the molten metal for 3 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. The results are shown in Table 4.

[0014]

[Table 4]

The break ring of the product 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. The BN quality is smaller than the break ring of the material formed by adjusting the water content of the SIALON-BN of the present invention for melting loss, permeation and oxidation, but it is expensive and cannot be used.

[0016]

The SIA of the present invention is similar to the results of the above embodiment.
The break ring made of LON-BN by adjusting the water content is small in melting loss and penetration from steel, stainless steel, etc. Therefore, the life of the break ring is long and the manufacturing of steel, stainless steel, etc. is safe and the manufacturing cost is low. Become.

Claims (4)

[Claims] 1. A horizontal continuous casting break ring made of steel, stainless steel or the like, the constituent components of which are SIALON-BN formed by adjusting the water content. 2. The SIALON has a chemical formula of Si ₆ -zAl.
The break ring for horizontal continuous casting according to claim 1, wherein a Z value in zOzN ₈ -z is 0.1 to 2.5. 3. The horizontal continuous casting braeing according to claim 1, wherein the BN is 10 to 40% by weight. 4. The break ring for horizontal continuous casting according to claim 1, 2 or 3, wherein the water content is adjusted by adding 1 to 5% by weight of water to the spray granules.