JPH105943A - Nozzle for continuous casting and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability without requiring any skillful technology by attaching and calcining a ceramic paper to a surface in contact with the molten steel of a nozzle body to form a non-carbon layer. SOLUTION: A nozzle comprises a nozzle body 1 formed of a refractory material containing carbon such as alumina carbon and magnesia carbon, and a non-carbon layer 4 consisting of a ceramic fiber layer in which a ceramic paper is attached to an inner circumferential surface of the nozzle body 1 through the binder and calcined to be integrated with the nozzle body 1. A caption number 5 denotes an outflow hole, and 6 denotes a refractory provided on an outer circumference of a part in contact with a slag line. The nozzle is manufactured by the process to knead the refractory material containing carbon at the prescribed ratio, a process to form a stock material for the nozzle body of the kneaded refractory material, a process to dry the formed stock material for the nozzle body, a process to attach a ceramic paper to an inner circumferential surface of the dried stock material of the nozzle body through the binder, and a process to calcine the ceramic paper after attachment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuous casting nozzle and a method for producing the same.

[0002]

2. Description of the Related Art In a continuous casting facility, a nozzle (immersion nozzle) is provided at the bottom of a molten metal container such as a tundish, and the lower portion of the nozzle is immersed in a water-cooled mold. Molten metal is continuously discharged into the mold from an outflow hole opened around the lower portion, and the molten metal whose periphery is cooled is discharged from the lower portion of the mold and guided to the next step.

[0003] The nozzle for continuous casting as described above has a property that inclusions (for example, alumina) and ingots contained in a molten metal (molten steel) do not easily adhere to the nozzle and there is no carbon pickup when casting low carbon steel. Required to have.

[0004] As a technique to meet the above demand, Japanese Patent Laid-Open No.
As shown in JP-39214, a two-layer structure in which a refractory material containing no carbon is stuck from the inner peripheral surface to the lower outer peripheral surface of a nozzle body made of a material containing carbon with a joint material to form a two-layer structure, A nozzle body containing the material for the nozzle body and a material containing no carbon are simultaneously formed, and the inner peripheral surface of the nozzle body is formed of a layer containing no carbon to form a two-layer structure. And a two-layer structure by pouring an amorphous castable material that does not contain the compound using a mold.

[0005]

However, when the non-carbon material is stuck using the joint material as described above, peeling occurs during preheating, and the non-carbon material is easily damaged by the flow of molten steel flowing in the nozzle. There's a problem. Also,
As described above, the method of simultaneously forming or casting a non-carbon material has a problem that the manufacturing process is complicated, a high skill is required, and the cost is high.

[0006]

SUMMARY OF THE INVENTION The present invention provides a non-carbon-based material having high resistance to the inclusion of inclusions or metal in molten steel on the inner peripheral surface of a nozzle and having no carbon pickup. It is an object of the present invention to provide a continuous casting nozzle which can be obtained at low cost and a method for manufacturing the same.

[0007] As means for solving the above problems, the present invention provides:
Another object of the present invention is to provide a configuration having a non-carbon layer integrated with the nozzle body by sticking ceramic paper on the inner peripheral surface of the nozzle body and firing it. In the production of the above nozzle, a step of kneading a refractory material containing carbon, a step of molding a nozzle body body with the kneaded material, a step of drying the molded nozzle body body, and a step of drying the dried nozzle body A step of adhering ceramic paper to the inner peripheral surface of the main body via a binder, and a step of firing after adhering the ceramic paper to obtain a nozzle integrally having a non-carbon layer on the inner peripheral surface of the nozzle main body. That's what I did. In the above-described manufacturing process, a step of forming the nozzle main body, firing the nozzle main body, and attaching ceramic paper to the inner peripheral surface of the nozzle main body may be interposed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows a cross section of an embodiment of a continuous casting nozzle according to the present invention, and FIG. 2 shows an enlarged cross section taken along the line AA of FIG. 1, and shows a refractory containing carbon such as alumina carbon and magnesium carbon. Nozzle body 1 made of material
Then, ceramic paper 2 is adhered to the inner peripheral surface of the nozzle body 1 via a binder 3 and then fired.
And a non-carbon layer 4 composed of an integrated ceramic fiber layer. In FIG. 1, reference numeral 5 denotes an outflow hole, and reference numeral 6 denotes a refractory provided on the outer periphery of a portion in contact with the slag line.

As shown in the process chart of FIG. 3, a step 10 of kneading a refractory material containing carbon at a predetermined ratio, and forming a nozzle body 1a from the kneaded refractory material, as shown in the process diagram of FIG. Step 11, a step 12 of drying the nozzle body body 1a after molding, a step 13 of attaching the ceramic paper 2 to the inner peripheral surface of the dried nozzle body body 1a via the binder 3, and a step 13 of ceramic paper Step 14 of baking after sticking of No. 2 gives a product. After the nozzle main body 1a is dried, a firing step 15 may be inserted as shown in FIG.

The thickness of the ceramic paper 2 is 1 to 6 m.
m, and preferably 2 to 4 mm. The firing temperature of the nozzle body 1a before the ceramic paper 2 is applied and the firing temperature after the ceramic paper 2 is applied is about 800 to 1300 ° C.
00-1200 ° C.

The binder 3 for attaching the ceramic paper 2 is made of a material containing sodium silicate, for example, SiO ₂ .
_{7, Na 2 O ... 10,} MgO ... 20 or SiO _2,
, 75, Na ₂ O .... 25, an inorganic binder of a chemical component, a water-based adhesive containing an inorganic pigment as a main component, or the like can be used.

By adhering the ceramic paper 2 using the binder 3 and firing at the above temperature, the ceramic paper 2 is melted or semi-melted, and a portion is fired to form the inside of the nozzle body 1a. A non-carbon layer 4 made of ceramic is formed on the peripheral surface. In this case, the thickness of the non-carbon layer 4 to be formed is not necessarily uniform, but when ceramic paper having a thickness of 3 mm is used, it is 1 to 2 m.
m, and is integrated with the nozzle body 1.

Therefore, since the inner peripheral surface of the nozzle is covered with the non-carbon layer 4, there is no adhesion of alumina interposed in the molten steel and no pickup of carbon material in the carbon-based material of the nozzle.

The ceramic paper is made of Al ₂ O ₃ 4
7-48%, those of SiO ₂ fifty-three to fifty-two% thickness 1
の も の 2 mm, the shrinkage when heated at 1000 ° C. for 2 hours is −0.3% to 0,
Even if it is heated for a period of time, it is about -2.0 to -5.5%.
Showed a tendency to harden.

[0016]

As described above, according to the present invention, the non-carbon layer is formed tough by sticking and firing ceramic paper on the surface of the nozzle body in contact with the molten steel to form the non-carbon layer. Can be easily performed, and damage due to molten steel flow can be prevented. In particular, since ceramic paper is attached, there is an advantage that the manufacturing process is not complicated and no skill is required. In actual use, the adhesion of inclusions such as alumina is drastically reduced, there is no carbon pickup in the nozzle material, and the durability is remarkably increased. Conventionally, 3 to 4 CC (continuous casting) has been 6 to 8
The life could be extended to CC.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a continuous casting nozzle according to the present invention.

FIG. 2 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 3 is a process chart showing a method for manufacturing a continuous casting nozzle of the present invention.

FIG. 4 is a process chart showing another manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle main body 1a Nozzle main body 2 Ceramic paper 3 Binder 4 Non-carbon layer

Claims (3)

[Claims] 1. A continuous casting nozzle comprising a non-carbon layer integrated with a nozzle body by sticking and firing ceramic paper on the inner peripheral surface of the nozzle body. 2. A step of kneading a refractory material containing carbon, a step of forming a nozzle body body from the kneaded material, a step of drying the formed nozzle body body, and a step of drying the nozzle body body after drying. A step of attaching ceramic paper to the inner peripheral surface of the nozzle via a binder, and a step of firing after attaching the ceramic paper, to obtain a nozzle having a non-carbon layer integrally on the inner peripheral surface of the nozzle body. Manufacturing method of a continuous casting nozzle. 3. A step of kneading a refractory material containing carbon, a step of forming a nozzle body body from the kneaded material, a step of drying the formed nozzle body body, and a step of drying the nozzle body body after drying. Baking, and a step of sticking ceramic paper to the inner peripheral surface of the fired nozzle body body via a binder, and a step of firing after adhering the ceramic paper, the inner peripheral surface of the nozzle body A method for producing a nozzle for continuous casting, comprising obtaining a nozzle having a non-carbon layer integrally.