JPS62244550A - Mesh filter having inoculation action - Google Patents

Abstract

PURPOSE:To easily remove foreign matters in molten metal and to easily and in inoculant by giving form-keeping property by coating a sticking agent composing of a caking material, which adds the inoculant on a mesh textile cloth formed by glass fiber having high SiO2 content. CONSTITUTION:The mesh fiber is formed by weaving as bundling the glass fiber having >=75wt% SiO2 composition. In this fiber, the sticking agent adding the inoculant, such as Fe-Si series, etc., in the cake material is coated and dried, to give the form-keeping property and also improve a flexual rigidity. This mesh filter has the excellent heat resistance, and removes as filtering the foreign matters in the molten metal having high m.p. Further, at the time of casting, flowing molten metal is effectively inoculated and the inoculation timing is easily taken.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to removing foreign matter such as slag and non-metallic inclusions suspended in molten cast iron or cast steel, as well as inoculating the molten metal. Regarding a reticular filter that can be used.

(Prior Art) Conventionally, there is a reticular filter in which a solidifying agent such as a phenol resin is applied to a reticular woven fabric made by weaving glass fibers with a low SiO2 content in a mesh shape to impart shape retention.

This mesh filter is used as a filter for filtering molten metals with low melting points such as aluminum and its alloys, and is attracting attention because of its excellent ability to remove slag and the like from the molten metal.

(Problems that dry throat attempts to solve) However, such a mesh filter has poor heat resistance and cannot be used as a filter for filtrating molten metal of cast iron or cast steel having a high melting point.

Therefore, in Japanese Patent Application No. 60-235032, the present inventor proposed a glass fiber mesh filter that can be used even for high melting point molten metals.

The reticulated filter proposed by the present inventor has improved heat resistance by increasing the 3402 content in the glass fibers to 75% by weight or more, making it applicable to high melting point metal molten metals.

However, when casting products by placing a mesh filter in the middle of the mold sprue or runner, adding an inoculant to the molten metal flow during pouring to improve the structure of the cast metal may cause the following problems. occurs. That is, in order to include the inoculant in the molten product, the particle size of the inoculant used must be smaller than the mesh size of the filter. but,
Even if the mesh size of the filter and the particle size of the inoculant are well combined, it is difficult to match the timing of pouring and adding the inoculant. That is, if the inoculant is added quickly, the inoculant is likely to be piled up and agglomerated on one of the filters, making it difficult for the inoculant to spread to the molten metal in the product casting part. On the other hand, if the hot water is poured quickly, the inoculating effect at the tip of the product tends to be insufficient.

The present invention was made in view of such problems, and an object of the present invention is to provide a mesh filter that can remove foreign substances such as slag from molten cast iron or cast steel, and also facilitates the addition of an inoculant during inoculation of the molten metal.

(Means for Solving the Problems) The feature of the mesh filter of the present invention, which was taken to achieve the purpose of soft soil, is that the 5iQ2 content is 75%.
A solidifying agent in which inoculant powder is added to a binding agent is applied to a net-like woven fabric made of glass fibers in an amount of % or more by weight, thereby imparting shape retention.

(Example) The reticulated woven fabric used as the material for the reticulated filter of the present invention is formed by weaving a bundle of glass long fibers having a diameter of 3 to 9 μm and an SiO2 composition of 75% by weight or more.

The SiO2 composition is 75% by weight or more at 1450°C.
This is to make it compatible with all types of molten cast iron. If SiO2 is of high purity, it can be applied to molten cast steel at 1500°C or higher. Here, compatibility means that the fibers do not turn into slag even when immersed in molten metal for 20 seconds. The above-mentioned 20 seconds was set because the pouring time is usually within this range.

In order to increase the 5iOz content of the glass fibers, the glass fibers may be subjected to acid treatment. i.e. hydrochloric acid, nitric acid,
Glass fibers mainly composed of silica are immersed in an acidic solution such as sulfuric acid with a catalyst added to promote the reaction, and impurities such as CaO and MHO are extracted while controlling the temperature, time, and concentration of the acidic solution.

Pe2(lh, Cr20B, Na2O, K20.
The content of TiO2, 8201, etc. is lowered, and as a result, the content of SiO2 is increased.

The opening size of the reticulated woven fabric depends on the size of slag, slag, etc. in the molten metal, but usually 0.4 to 411 is sufficient.

A mixture of a binder and an inoculant powder is used as a solidifying agent to impart shape retention to the reticulated woven fabric.

As a binder, acidic novolak phenol resin,
Examples include neutral phenol resin, starch paste, and acidic silica sol solution.

As the inoculant added to the binder, an easily available Fe-3i inoculant is generally used.

The inoculant is preferably in powder form with a particle size of about 0.1 to 0.25 nm. This particle size is preferred because it is the smallest particle size range that can be supplied on a commercial basis, and because it is the easiest to adhere to when the solidifying agent is applied to the reticulated fabric.

The content of the inoculant in the solidifying agent is preferably 20 to 50% by weight. If the vaccination rate is less than 20%, the vaccination effect will not be effective;
This is because if the solidifying agent exceeds the viscosity, the viscosity of the solidifying agent becomes too high, making it difficult to adhere to the reticulated woven fabric.

When the net-like woven fabric coated with the solidifying agent is dried at 150° C. for about 20 minutes, the flexural rigidity of the woven fabric is improved and sufficient shape retention is imparted.

An example of the use of the reticular filter according to the present invention is shown in FIG.

In the figure, a mesh filter 1 according to the present invention is arranged on a parting surface 3 at the bottom of a sprue 2, 4 is an upper mold, 5 is a lower mold, 6 is a hanging weir, 7 is a runner, and 8 is a pusher. A molten metal casting space, 9 a product casting space, and 10 a sprue bottom.

(Effects of the Invention) As explained above, the reticulated filter of the present invention has a reticulated woven fabric made of glass fibers containing high-purity SiO2, so it has excellent heat resistance and is suitable for use in high melting point cast iron and molten cast steel. Foreign substances can be filtered out.

In addition, since the reticulated woven fabric is coated with a solidifying agent containing inoculant powder, it can be effectively inoculated with molten metal during product casting, and the timing of inoculation can be easily determined when inoculating molten metal. Become.

Furthermore, since the inoculation can be applied to clean molten metal from which slag and the like have been removed, the inoculation effect is improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a mold structure in which a mesh filter of the present invention is installed. Patent applicant: Kubota Iron Works Co., Ltd. Figure 7

Claims (1)

[Claims] (1) In a reticular filter in which a solidifying agent is applied to a reticular woven fabric formed of glass fibers to provide shape retention, the glass fiber has an SiO_2 content of 75% by weight or more, and the solidifying agent is a caking agent. 1. A reticular filter having an inoculating effect, characterized in that an inoculant powder is added to the agent.