JPH0474830A - Side plate of cartridge for molten metal - Google Patents

Abstract

PURPOSE:To inexpensively obtain the stable side plates having low reactivity with a molten metal by constituting the side plates of a cartridge for the molten metal of SiC contg. specific ratios of Al2O3, Fe2O3 and SiO2. CONSTITUTION:The chemical compsn. of the side plates 1 of the cartridge 3 for the molten metal formed by assembling plural pieces of filter tubes 2 with the side plates 1 of silicon carbide facing each other are composed of 0.5 to 5 wt.% Al2O3, 0.3 to 3 wt.% Fe2O3, 5 to 15 wt.% SiO2 and the balance SiC. Of the chemical compsn. of such side plates 1, >=20 wt.% of the SiO2 is preferably crystobalatized SiO2. The reactivity with the molten metal and more particularly molten aluminum is lowered by specifying the chemical compsn. of the side plates 1 to the above-mentioned range. The stable side plates 1 are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a side plate of a molten metal cartridge suitable for filtering impurities (inclusions) contained in molten metal, particularly molten aluminum.

[Prior Art and Problems to be Solved by the Invention] Metal thin plates and foils are manufactured by casting molten metal into an ingot and rolling the ingot. However, if solid impurities such as metal oxides and minute fragments of refractories contained in molten metal are mixed into the ingot, pinholes and surface defects can occur during the process of rolling the ingot into thin sheets, foils, etc. There are things to do. To prevent this, it is necessary to remove solid impurities from the molten metal.
As shown in Japanese Patent Application Laid-open No. 22327 and Japanese Patent Application Laid-open No. 64-21019, for example, as shown in Figure 1, aggregate particles such as silicon carbide or alumina are bonded with an inorganic binder to form a large number of particles between the aggregate particles. A molten metal filtration device is constructed by assembling a cartridge 3 by fixing a plurality of filter tubes 2 each having a structure of continuous fine pores with opposite side plates 1, and fixing the cartridge 3 to a storage tank 5 with a wedge plate 4. It has come to be used as a preferred method.

The side plate l used in such a cartridge is made of high temperature (750°C) molten metal (e.g. molten aluminum).
6, it is necessary to have sufficient heat resistance, and in order to withstand the impact when the wedge plate 4 is driven in, it is required to have a bending strength higher than a predetermined value.

In addition, the purpose of this filtration device is to remove impurities from the molten metal, so the material of the side plate must be a stable material that will not contaminate the molten metal by eluting its components into the molten metal. requested.

[Means for Solving the Problems] Therefore, the inventors of the present invention conducted various studies in order to meet the above requirements, and found that by using an oxide-bonded silicon carbide refractory as the material of the side plate, the above requirements could be met. We have found that the following can be satisfied, and have arrived at the present invention.

That is, according to the present inventor, there is a side plate of a cartridge for molten metal, which is constructed by assembling a plurality of filter tubes with opposed side plates made of silicon carbide, and the chemical composition of the side plate is A2O3O, S ~ 5% by weight, Fe2030.3
~3% by weight, 5i025~15% by weight, the balance being SiC, a side plate of a cartridge for molten metal,
is provided.

Furthermore, in the chemical composition of the side plate, it is preferable that 20% by weight or more of the amount of SiO2 is converted into cristobalite.

[Function] The side plate of the present invention is characterized in that it is made of silicon carbide with oxide bonds and has a specific chemical composition. Therefore, it has a strength above the specified level required for a cartridge for molten metal, and also
The amount of 2 is extremely small.

The chemical composition of the side plate of the present invention is Al 203 of 0°5 to
5% by weight, preferably 1-4% by weight, Fe2O3 0.
3-3% by weight, preferably 0.8-2% by weight, SiO2
By setting the chemical composition of the side plate within the above range, in which the amount is 5 to 15% by weight, preferably 7 to 12% by weight, and the balance is silicon carbide (SiC), reactivity with molten metal, especially molten aluminum, can be lowered. , it becomes a stable side plate.

In addition, in the chemical composition of the side plate, 20% by weight of the amount of SiO2
It is preferable that the above is converted into cristobalite because the reaction resistance to molten metal is further improved.

[Example] The present invention will be explained in more detail based on an example below.
The present invention is not limited to these examples.

(Examples 1 to 12) Silicon carbide (SiC) having a maximum particle size of 3.5 mm and smaller continuous particle sizes was used.
Change the amount of fine powder below and mix A.

03, Fex 03, and S 10x were added as shown in Table 1 to adjust the chemical composition. In addition, 5i01!
The amount was adjusted to a particle size of 88 L1 or less depending on the firing conditions.

The above materials were kneaded, molded into a plate-shaped body of 300x300x50mm, and fired at a dry temperature of over $1300'C.

The chemical composition of the obtained fired body and the amount of cristobalite in 0 g of Si were measured, and the fired body was determined according to JIS1.
The fired body was immersed in 050 aluminum molten metal at 750°C for 24 hours, and the amount of components eluted from the fired body was examined. In addition, the bulk specific gravity of the fired body and the bending strength by three-point bending were measured by the boiling method. The results are shown in Table 1.

As is clear from Table 1, it can be seen that those having the composition range of the present invention show good results.

(Hereinafter, blank space) (Comparative Examples 1 to 2) Sintered in the same manner as Examples 1 to 12, except that the amount of Al2O in the chemical composition of the fired body was outside the range of 0.5 to 5% by weight. Created a body. The obtained fired body was prepared in Examples 1 to 2.
As shown in Table 2, the results were that the amount of Si eluted exceeded the allowable range or the bending strength was low.

(Comparative Examples 3 to 4) Fired bodies were created in the same manner as Examples 1 to 12, except that the amount of Fe2O in the chemical composition of the fired body was outside the range of 0.3 to 3% by weight. The obtained fired bodies were measured in the same manner as in Examples 1 to 12, and as shown in Table 2, the results showed that the bending strength was low or the amount of Fe eluted was unacceptably large. It became.

(Comparative Examples 5 to 6) The amount of SiO2 in the chemical composition of the fired body was 5 to 15% by weight.
Fired bodies were created in the same manner as in Examples 1 to 12, except that the temperature was outside the range of . Regarding the obtained fired body, Example 1
When measurements were carried out in the same manner as in 12 to 12, as shown in Table 2, the results were that the bending strength was low or that the amount of Si eluted was large.

(Comparative Examples 7-8) When a fired body was created in the same manner as in Examples 1-12 and measured using the same method, it was found that S of the chemical composition of the fired body was
As shown in Table 2, in cases where less than 20% by weight of iO2 was cristobalite, the result was that the amount of Si eluted was large.

(Hereinafter, blank spaces) (Example 13) A side plate for a set of 14 filter tubes was manufactured using the chemical composition shown in Example 3 of Table 1, and a cartridge 3 was assembled together with the filter tube 2. When this cartridge 3 was loaded onto a truck for a running test, and when it was actually set in the storage tank 5 (see Figure 1) and the wedge plate 4 was driven in, no cracks were observed in both the side plate 1 and the filter tube 2. It was found that the material was strong enough to last.

[Effects of the Invention] As explained above, the side plate of the cartridge for molten metal of the present invention is made of silicon carbide with oxide bonds, which has a characteristic chemical composition, and is reactive to molten metal such as molten aluminum. It is low, stable and has sufficient strength.

Moreover, this side plate is cheaper than a silicon carbide side plate having a silicon nitride bond or a silicon carbide side plate having a silicon carbide bond, and is excellent in economical efficiency.

[Brief explanation of the drawing]

Figure 1 shows the cross section of a cartridge for molten metal!
This is the essential diagram. 1... Side plate, 2... Filter tube, 3...
Cartridge, 4... Wedge plate, 5... Storage tank, 6
...Molten metal. Diagram

Claims (2)

[Claims] (1) A side plate of a cartridge for molten metal, which is constructed by assembling a plurality of filter tubes with side plates made of silicon carbide that face each other, and the chemical composition of the side plate is Al_2O_
30.5-5% by weight, Fe_2O_30.3-3% by weight
, a side plate of a cartridge for molten metal, characterized in that SiO_25 to 15% by weight and the balance being SiC. (2) The side plate for a cartridge for molten metal according to claim 1, wherein in the chemical composition of the side plate, 20% by weight or more of SiO_2 is cristobalite.