JPS589870A - Casting nozzle composition - 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 a casting nozzle composition suitable for extrusion molding.

Among the recent developments in steelmaking technology, casting nozzles such as long nozzle immersion nozzles have been widely adopted as a method of preventing oxidation of molten steel in continuous casting and clean steel manufacturing. At present, a large amount of rubber is used, and furthermore, it is molded and processed using an L-shaped rerubber press.

The characteristics of the rubber press (W1) are uniform pressure, problems with the alignment of graphite, poor dimensional accuracy and molding efficiency, high cost, and the need for finishing processes such as polishing and cutting, making it difficult to manufacture. Long time! ! There are some problems TW.

On the other hand, the extrusion molding method has been attempted in the past, but in this method, the formation of molten metal outflow holes is done only after firing, as shown in the patent publication No. 48-28329, so the manufacturing process is complicated and efficiency is reduced. Too bad. In addition, even in the conventional molding method using an auger machine, the core mandrel for forming the molten fat outflow hole is fixed to the base mold via a beam, and during molding, the molded object is cut and separated in one piece at the beam part. This method was used to obtain an integral cylindrical molded body after being rejoined. In this method, there was no problem with rejoining when the nozzle material did not contain graphite or contained a small amount of graphite, but when a large amount of graphite was mixed, there was no problem at the molding stage, but the table below shows After firing, there is a problem that cracks occur in the rejoined parts, especially when subjected to shock during operation.

Using an auger machine, which is an efficient manufacturing method, we are able to form molten metal outflow holes by eliminating the fixation with beams, which was a factor in the generation of cracks in the past.
A method of simultaneous molding was proposed.

This method enables simultaneous molding of the flange portion, etc., has good dimensional accuracy, requires no machining, and can be molded continuously, dramatically improving manufacturing efficiency.

tytp) In order to remove the sharp air in the soil, the deaeration mechanism may be one stage, but it should be two stages KL9 Note) (3)
) The above values are the quality after molding and baking. The number of degassing stages is the number of vacuum degassing mechanisms in the auger machine. However, in the shell extrusion molding method, the workability (moldability) of the compounded composition depends on the surface finish, lamination, etc. This will affect the leakage, filling properties, etc.

(Especially noticeable in graphite-containing blended compositions) The present invention provides a casting nozzle composition 1 that is suitable for the extrusion and extrusion methods and has no problems in terms of quality and practicality. Swallow lead-containing composition has a particle size of 0.5~
0.1 dew of scaly graphite t10-40 weight, bonded clay t-
10 to 30% by weight, with the remainder being made of a fire-resistant material.The present invention will be explained below along with some examples.

Examples were shown in the table below.

Note) Values after Qin molding and firing *11 Rapid heating at 400°C for 15 minutes, water cooling for 2 minutes, and air cooling for 13 minutes.Water is added to these blended compositions, kneaded, and molded using the auger machine mentioned above. In the low range where the weight is high, it is convenient to use resin, glue, etc. 7 in combination with Isobin binder.

From these results, it was found that not only the amount of clay but also the particle size of graphite have a significant effect. The graphite particle size is preferably 0.5 to 0.1-, and if it is 0.5- or more, workability (especially If it is less than 0.1, it will result in poor workability (increased compound volume and poor bonding) and quality (decrease in bulk specific gravity, increase in porosity, and compression). decrease in strength, etc.).

The amount of graphite is preferably 10 to 40% by weight, and 10 to 40% by weight.
If the weight is lower than 40, corrosion resistance and spalling resistance will decrease.
If the weight exceeds 10%, the workability (decreased molded body shape retention ability and tends to cause lamination) will be poor, and the amount of clay is preferably 10 to 30% by weight.
If the weight is less than
If the weight exceeds 30%, corrosion resistance and spalling resistance decrease.

It was found that when the long nozzle of the present invention @ was used in a 50-ton ladle made by kA steel, it could sufficiently withstand not only cracking but also corrosion of molten steel even after 2 charges.

In addition, the nozzles of the present invention and the conventional example are shown side by side in Figure 9, Figure 1 tCa shows the present invention, and Figure 1 shows the conventional example. Indicates the outflow hole, (
2) indicates a crack;

[Brief explanation of the drawing]

Figure 1 a*bh is an overhead view of a nozzle according to the present invention and a conventional example. 1... Molten metal outflow hole 2... Crack inventor
So Kojima - Inventor Tsuneo Arata Applicant Kurosaki Rozai Co., Ltd. Representative Kazuumi Miya Take Applicant Kurosaki Ceramics Co., Ltd. B/A 0, b.

Claims (1)

[Claims] 110 to 40% by weight of scaly graphite with a particle size of 0.5 to 0.1 mm,
A nozzle composition for casting in an extrusion molding process, characterized in that the bound clay tlO~30 weight residue is made of a refractory material.