JPH05228581A - Cooling mold for drawing-up continuous casting - Google Patents

Abstract

PURPOSE:To enable molten metal temp. contacting with a mold hole of a cooling mold to low temp. at the molten metal surface side and to high temp. at the lower part. CONSTITUTION:In the cooling mold for drawing-up continuous casting constituted by fitting a heat-resistant sleeve 2 in the inner surface of the mold 3, a nozzle 1 is fitted toward inner part at the lower end of the sleeve 2, and an annular space 12 is formed between a cylindrical part 11 of the nozzle 1 and the inner surface of the sleeve 2, and the lower end of the annular space 12 is closed at the same position. By this method, i.e., by arranging the nozzle 1 at the lower part of the mold, the molten metal is passed through the nozzle 11 in which the upper end reaches to the neighborhood of the molten metal surface, and supplied into the mold, and since the molten metal is flowed into the annular space 12 between the cylindrical part 11 of the nozzle 1 and the sleeve 2 after once passing through the neighborhood of the molten metal surface, in the upper part and the lower part of the annular space 12, the molten metal temp. at the lower part side is lower than the temp. at the upper part side. Therefore, the temp. distribution of the molten metal contacting with the sleeve 2 becomes the desirable condition and the firm shell is formed in the solidification at the initial stage and the inner surface at the upper part of the sleeve 2 is solidified and formed in good condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling mold for pulling continuous casting.

[0002]

2. Description of the Related Art Cooling molds used for pulling continuous casting are
As shown in FIG. 2, the cylindrical mold (3) is surrounded by an annular cooling jacket (4) to protect the outer circumference and the bottom surface of the jacket (4) with a refractory layer (5) and the mold (3). A tubular sleeve (2) having excellent heat resistance is fitted to the inside of the sleeve (2), and the inner surface of the sleeve (2) forms a mold hole corresponding to the outer diameter of the tubular body (8) to be manufactured.

The upper part of the cooling mold is exposed from the surface of the molten metal, the lower part is immersed in the molten metal (7), and the molten metal is placed in the sleeve (2).
Infiltrate (7).

Cooling jacket surrounding the sleeve (2)
While cooling and solidifying the molten metal (7) along the mold cavity with the cooling water in (4), the solidified layer is intermittently pulled up by a pulling device (6) such as a pinch roller to pull up the tubular body (8). It is a continuous casting.

[0005]

In pulling continuous casting, the melt temperature is an important factor for obtaining a good cast product, and in the part where the initial solidified shell at the bottom of the mold is formed,
In order to form a strong solidified shell, it is desirable that the temperature of the molten metal be low near the liquidus temperature.

On the other hand, in the vicinity of the molten metal surface where the innermost surface is formed,
When the temperature of the molten metal is low, a weight-like projection is formed, and the step difference generated on the inner surface of the tube body due to the intermittent pulling increases, and the inner surface properties deteriorate.

However, in the conventional mold, in the mold,
It was extremely difficult to control the temperature of the molten metal so that the temperature of the molten metal in the lower part of the mold becomes higher than that in the vicinity of the molten metal surface and the temperature of the lower part of the mold becomes lower than that in the vicinity of the molten metal surface. The present invention reveals a cooling mold for continuous pulling casting in which the above problems can be solved by improving the mold itself.

[0008]

A cooling mold for pulling and continuous casting according to the present invention surrounds a cylindrical mold (3) with a cooling jacket (4) and protects the jacket (4) with a refractory layer (5). Then, in a cooling casting mold for pulling up continuous casting constituted by fitting a heat resistant sleeve (2) to the inner surface of the mold (3), the nozzle (1) is attached to the lower end of the sleeve (2), (1) has a tubular portion (11) protruding into the mold, an annular space (12) is formed between the tubular portion (11) and the inner surface of the sleeve (2), and the lower end of the annular space (12) Are closed at the same height.

[0009]

[Operation and effect] By providing the nozzle (1) in the lower part of the mold, the molten metal is supplied into the mold through the nozzle (1) whose upper end reaches the vicinity of the molten metal surface, that is, the molten metal is once melted on the molten metal surface. Since it passes through the vicinity and flows into the annular space (12) between the tubular portion (11) of the nozzle (1) and the sleeve (2), the nozzle (1) becomes a great resistance against heat flow. In the upper part and the lower part of the annular space (12), the temperature of the molten metal on the lower side becomes lower than that on the upper side.

As a result, the temperature distribution of the molten metal in contact with the sleeve (2) is in a desirable state, a strong shell is formed in the initial solidification, and the inner surface is solidified and formed in a good condition in the upper portion of the sleeve (2). To be done.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a cooling mold of the present invention, in which a copper cylindrical mold (3) is surrounded by an annular cooling jacket (4), and the outer circumference and bottom surface of the jacket are surrounded. It is protected by a refractory layer (5).

A water chamber (41) filled with cooling water is formed inside the cooling jacket (4). The cylindrical sleeve (2) is tightly fitted in the mold (3). Above sleeve
In (2), the upper part is made of graphite and the lower part is made of boron nitride. A nozzle (1) made of boron nitride is mounted inward on the lower part of the sleeve (2).

The tip of the tubular part (11) of the nozzle (1) reaches a position slightly lower than the molten metal surface, and an annular space (12) is formed between the tubular part (11) and the sleeve (2). ing. Above annular space (12)
Are closed at the same height near the lower end of the sleeve (2).

A spiral groove (13) is formed on the outer periphery of the lower portion of the nozzle (1), and a refractory material enters the groove to fix the nozzle (1).

However, since the nozzle (1) is provided in the lower part of the mold, the molten metal is a nozzle whose upper end reaches near the molten metal surface.
After passing through (1), it is supplied into the mold, that is, the molten metal once passes near the surface of the molten metal, and the tubular portion (11) of the nozzle (1) and the sleeve (2).
Flows into the annular space (12) of the nozzle (1), and the nozzle (1) has a large resistance to the flow of heat.
In the upper part and the lower part of the annular space (12) between the (1) and the sleeve (2), the temperature of the molten metal on the lower side is lower than that on the upper side.

As a result, the temperature distribution of the molten metal in contact with the sleeve (2) is in a desired state, a strong shell is formed in the initial solidification, and the upper surface of the sleeve (2) is solidified and the inner surface is solidified. To be done. The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the claims.

[0017]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cooling mold of the present invention.

FIG. 2 is a cross-sectional view of a conventional cooling mold.

[Explanation of symbols]

 (1) Nozzle (11) Tube part (12) Annular space (2) Mold (3) Sleeve

Claims (1)

[Claims] 1. A cooling jacket for a cylindrical mold (3)
Surround the jacket (4) with a refractory layer
Heat-resistant sleeve protected by (5) and on the inner surface of the mold (3)
In a cooling casting mold for pulling continuous casting, which is configured by fitting (2), a nozzle (1) is attached to the lower end of a sleeve (2), and the nozzle (1) projects into a mold (11). ), And the tubular part (1
A cooling mold for continuous casting for pulling up, wherein an annular space (12) is formed between 1) and the inner surface of the sleeve (2), and the lower end of the annular space (12) is closed at the same height position.