JPS59120349A - Casting mold for continuous casting of copper or copper alloy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mold for continuous casting of heavy steel or copper alloy.

Water-cooled molds with inner walls made of copper or graphite and containing cooling water channels are used as molds for continuous casting of heavy steel or copper alloys, but these molds have the following problems: .

(1) The solidification line in the belt is constantly fluctuating due to subtle changes in mold cooling water and changes in the flow of hot metal supply, and the macrostructure of the ingot is also unstable, which may cause cracks in subsequent processes.

(2) Foreign matter such as oxides floating on the surface of the molten metal due to fluctuations in the solidification line, or if they are entrained on the surface of the molten metal, entrainment including coating material may occur, greatly affecting the surface properties of the ingot. Become something.

(3) In cake casting, the cooling ability near the corners of the mold becomes weaker, so the solidification line rises, making it easier to generate oxides and to cause these products to be dragged in. This phenomenon is particularly noticeable in copper alloys containing elements that are easily oxidized.

(4) In the case of copper alloys containing easily oxidized elements, C
;1. A film-like oxide is formed near the molten metal surface of the cast strip, and as it adheres, it forms a local heat insulating layer, and a solidified film is formed on this surface, resulting in a smooth sliding surface. The skin is formed, the oscillation marks disappear, and an abnormal cast surface appears. However, if film-like oxides are periodically involved, the influence on the inside of the ingot will be greater.

(5) Steel heavy graphite used as a cast strip is oxidized or physically worn due to the heat of elution.
Because of the roughness of the casting mat ('K), it cannot withstand long-term use, and the cost of materials and replacement overlays are enormous.

One object of the present invention is to eliminate the drawbacks of the prior art and to provide a mold that can rapidly produce ingots with stable internal structure and surface properties.

According to the present invention, the purpose of the present invention is to use a material with poor wettability, which has a lower heat transfer coefficient than copper and has heat resistance and wear resistance, from the vicinity of the mold where the elution of the mold contacts and solidifies. This can be achieved by lining the interior with heat insulating and refractory H. As an example of such a heat insulating and refractory H, then, "S II
An example of this is Alumina Phi Me Molding A, which is known under the trade name '+3' and can be used at temperatures of 1600℃.

4: To explain with reference to the illustrations, FIG. 1 shows an example of continuous casting of copper alloy using the steel 1471'i according to the present invention.

The molten metal 2 supplied to the tundish 1 and subjected to cleaning treatment is controlled to have a supply loss by a control valve 3, and is passed through a descending pipe 4 (-7 to distribution 2 to 5 to 5y7, and passed through several holes). The inside of the water-cooled mold 6 is lined with graphite. A heat insulating surface made of alumina phi.
The lower inner side is gently sloped at a certain angle in the direction of ingot withdrawal.

As shown in FIG. 2, the pre-insulation refractory material 8 may be partially pushed into the water-cooled mold 6 and then directly raised at a certain fI'1 degree from the mold 7r). Figure 3 - 1 - This is an installation example in which the heat insulating ignition material 8 is completely pushed into the mold 6 to eliminate the level difference between it and the stain wall 7.

In either case, the surface of the molten metal 1(d) in the mold 6 is covered with the frame material 9, and maintained above the boundary between the heat insulating refractory material 8 and the mold 7.

In such a configuration, the molten metal 10 in the mold 6 is in a molten state at the part where it is in contact with the heat insulating and refractory layer 8 due to the heat retention effect of the heat insulating and refractory layer 8, and descends in the vicinity of the hole where it comes into contact with the mold 7. The molten metal 10 is rapidly cooled and begins to form a solidified part.Therefore, the molten metal 10 contains almost no floating oxides, y4 materials such as the material 9, etc., and film-like oxides do not form on the mold 7 near the surface of the molten metal. The formation of layers is also prevented, resulting in a good internal structure and casting surface.

Molten metal] to 0j: After that, it is cooled by the nyawar 12 and the secondary nyawara 13 from the mold 6, and becomes an ingot. It is pulled down by the anti-roll 14.

By the method shown in Fig. 1, (E u −Z r (0
, 05 Section) The alloy was continuously cast into a large cake material of 2] OX450 mm, but there was almost no oxide generation in the mold.
No withdrawal into the ingot occurred. In addition, no oxide film was formed near the molten metal surface, and ononray oxide marks were normally formed on the ingot surface, resulting in stable surface properties.

On the other hand, if a mold without heat insulating refractory material 8 is used, a large amount of oxide lumps will be generated in the mold, which will be drawn mainly into the C/8 side and part of the corners of the ingot and be cast. The surface properties of the lump become poor, and in extreme cases, there is a risk of breakout. It now produces a smooth casting surface.

As is clear from the above, according to the present invention, by installing the heat insulating refractory shell, the solidification line is stabilized by its heat retention effect, and the solidification shell is prevented from reaching the hot water surface in the well.
This prevents oxides, N+;t from getting caught in foreign matter, and also prevents the formation of oxides and other particles that occur near the corners of the mold when casting copper alloys. It is possible to stabilize the internal structure of the ingot along with preventing macro- and micro-structural segregation by stabilizing the cooling capacity. In addition, since the molten metal concentrates on the parts of the heat-insulating refractory material that have poor wettability, the formation of film-like oxides on the mold near the molten metal surface is prevented, and the surface texture with normal oscillation marks is improved. Not only can a stable ingot be obtained, but wear and tear on the mold can be prevented and only inexpensive refractory materials need to be replaced, which has the advantage of extending the life of the mold. Knee 6 = Industrial utility value A [tl is extremely dog-like.

[Brief explanation of drawings]

Figure 1 shows the casting 7C according to the present invention! A sectional view showing an example of 1,
FIGS. 2 and 3 are cross-sectional views showing other examples of casting A. 6゛Water-cooled mold, 7 four walls, 8: insulation fireproof'4: A-0-
・7- Figure 2 Peeling 7

Claims (1)

[Claims] (1) The molten metal injected into the water-cooled mold that houses the cooling channel system contacts and solidifies from the vicinity to the top. A mold for continuous casting of heavy steel or copper alloy, which is characterized by being closely lined with a heat-insulating refractory material of poor quality, suppressing the cooling ability of the upper part of the mold, and cutting off contact between the molten metal and the strip.