JPH08283816A - Molten metal processing agent - Google Patents

Abstract

PURPOSE: To uniformize diffusion of additives, to exhibit fine metallic structure in a product and thereby to improve material characteristics by packing plural additives for processing molten metal into respective middles of hollow bodies each having a multiple structure. CONSTITUTION: An external pipe 1 having 25mm outer diameter and 2.6mm wall thickness and an internal pipe 1 having 13mm outer diameter and 2mm wall thickness, for example, are prepared. The internal pipe 1 is evacuated and an FeSi inoculum 3 in a molten state is sucked and filled thereinto. After cooling, the internal pipe 1 is set in the external pipe 1 and then FeSiMg spheroidizing agent 2 in a molten state is again sucked and filled thereinto by reduced pressure and is warm press-molded to small pieces of 10mm length. The hollow pipe is a steel pipe or a nickel-alloy pipe. The molten metal processing agent has a specific gravity, by which the agent does not substantially float to a molten metal surface during treating the molten metal. As a result, preservability to damage to the products and to oxidation, moisture absorption, etc., of the additives can be maintained at the time of transporting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to cast iron, ductile cast iron and compacted vermicular (hereinafter CV).
The present invention relates to a molten metal treatment agent necessary for manufacturing cast iron and the like.

[0002]

2. Description of the Related Art In the production of cast iron for industrial use, metal graphitization treatment, graphite spheroidization treatment, CV treatment,
Desulfurization treatment, inoculation treatment, graphite miniaturization treatment, etc. are required,
Conventionally, a powder material in which an additive such as Mg or Si having a small specific gravity is alloyed with iron or nickel is pressed with a cover material to perform molten metal treatment, or a press-fitting device such as a plunger method or a wire method is used. The molten metal treatment has been carried out by using a special ladle.

However, since the kind and timing of addition of additives differ depending on the purpose of each treatment, it is difficult to perform ideal molten metal treatment when spheroidizing graphite while inoculating like ductile cast iron. . Further, the conventional additive has a small specific gravity and easily floats, so that the additive amount is large and it is uneconomical.

An object of the present invention is to solve the above-mentioned problems, and the inoculation and the spheroidizing treatment of graphite are continuously carried out while preventing the floating by increasing the specific gravity of the treating agent without using special equipment. It is to provide a molten metal treating agent that can be used.

[0005]

According to the present invention, two or more kinds of additives for treating molten metal used for treatment of molten metal by the pouring method are used, and each space of a multi-structure hollow body containing iron or nickel as a main component. It is a treating agent that is filled in the above and molded into small pieces if desired. It is a multipurpose molten metal treatment agent that can achieve a plurality of treatment purposes in a single treatment.

The additives for metal treatment used in the present invention include metal graphitization treatment, graphite spheroidization treatment, CV treatment,
Well-known additives used for desulfurization treatment, inoculation treatment, graphite refining treatment, etc. can be used. Therefore, its type is not particularly limited, and there are combinations of an inoculant and a spheroidizing agent or a CV agent. Specific examples of the additive include Mg alloy and FeS
Well-known additives such as i, fluorite, soda ash, and carbide can be exemplified.

According to the present invention, such an additive for metal treatment is coated with a metal containing iron or nickel as a main component to cover the whole or a main part thereof to form a small piece, which has a large apparent specific gravity and has a different purpose. By individually integrating and containing,
It is intended to provide a multipurpose molten metal treating agent capable of producing a high-quality product having a fine metal structure by substantially controlling the floating during the treatment of molten metal.

A metal tube is preferably used as the hollow metal body containing iron or nickel as a main component. As the metal pipe, an outer pipe having an inner diameter of 10 to 30 mm and an inner pipe having an outer diameter of 5 to 25 mm are preferably used, but in order to reliably perform vacuum suction filling, the outer pipe and the inner pipe shown in FIG. The gap is preferably 3 mm or more.

The state of the additive at the time of filling is in a molten state or a powdery state (here, the powdery state is the solid state of a conventionally used additive such as powder, granules and lumps). However, the molten state is preferable in order to obtain a more uniform and high density. When the molten additive is charged under reduced pressure, the molten additive is instantly charged by reducing the pressure at -200 to 650 mmHg. The additive is solidified by suction holding for several seconds after filling. Press molding after filling,
It is cut into small pieces. In the case of a powdery or granular material, it may be filled as it is, but it is preferable to fill it in a state of being bonded with a resin typified by a thermosetting resin in view of easiness of molding into a small piece shape and the like. The resin is preferably a thermosetting resin such as a phenol resin, an epoxy resin or an unsaturated polyester resin, but other resins can be used.

The size of the multi-purpose molten metal treating agent in the form of flakes increases as the amount of molten metal treated increases, but it is 1 to 30.
cm ³ is preferred. If the apparent specific gravity is in the range of 4.5 to 6.5, the levitation during processing can be controlled. FIG. 1 is a schematic view of a multipurpose molten metal treating agent having a double structure.

[0011]

【Example】

Example 1 An outer tube having an outer diameter of 25 mm and a wall thickness of 2.6 mm and an inner tube having an outer diameter of 13 mm and a wall thickness of 2 mm were prepared. First, the inner tube having an outer diameter of 13 mm was decompressed and suction-filled with a molten FeSi inoculant. . After cooling, the tube was set in a steel tube having an outer diameter of 25 mm, and the molten FeSiMg spheroidizing agent was suction-filled again under reduced pressure,
It was warm pressed into small pieces of 10 mm in length. In this case, the apparent specific gravity was 6.3. After setting this double-structured molten metal treating agent in a ladle, 200 kg of molten metal was poured into the ladle. As a result, there was no levitation, less white smoke was produced compared to the conventional method, the Mg yield of the product was high, and the number of graphite particles was remarkably increased especially compared with the conventional method. The results are shown in Table 1 and the metallographic structure is shown in FIG. It is considered that this result is that the inoculation and the addition of Mg were alternately performed during the molten metal treatment, and as a result of the continuous treatment, a very fine graphite structure was formed.

Example 2 An outer tube having an outer diameter of 30 mm and a wall thickness of 2.6 mm and an inner tube having an outer diameter of 16 mm and a wall thickness of 2 mm were prepared. First, the inner tube having an outer diameter of 16 mm was depressurized and coated with a thermosetting phenol resin. The powdered granular FeSiMg alloy is suction-filled under reduced pressure to 500K.
It was baked in. After cooling, the tube was set in a steel tube having an outer diameter of 30 mm, and the void was suction-filled with a powder-shaped inoculant coated with a thermosetting phenolic resin under reduced pressure.
It was cut and molded into small pieces having a length of 40 mm. This double-structured molten metal treating agent was set in a ladle and treated with 200 kg of molten metal. As a result, the same results as in Example 1 were exhibited, and the number of graphite particles was increased to about twice that of the conventional method.

[0013]

[Table 1]

[0014]

As described above, the molten metal treating agent of the present invention has the following characteristics. (1) The specific gravity of the molten metal treatment agent can be made very close to the specific gravity of the molten metal to be treated, and the floating of the molten metal treatment agent during treatment can be reliably prevented. For example, the specific gravity of cast iron molten metal is 7 to 7.2, and in the spheroidizing treatment, the specific gravity of the conventional spheroidizing agent rises to about 4.3, so it is necessary to use a cover material, etc. Is required. (2) In the molten metal treatment agent of the present invention, the coating material deprives the heat of fusion to lower the ambient temperature, and the coating materials fuse together to control levitation. . (3) Since the molten metal treating agent of the present invention is melted sequentially from the surface layer after treatment to cause convection of the molten metal, the inoculation time of the additive is long and the diffusion is uniform. Therefore, the product exhibits a very fine metallographic structure and the material properties are improved. (4) Since the molten metal treatment agent of the present invention is coated and protected by a strong metal plate, it can maintain its storability against breakage during transport, oxidation of additives, moisture absorption and the like. (5) By using the molten metal treating agent of the present invention,
The working environment such as white smoke and dust can be improved, and cleaning management of the ladle becomes easy. (6) The molten metal treating agent of the present invention has a multi-layered structure. For example, inoculation and spheroidization, or desulfurization and spheroidization
Since the additives with different purposes are coated and contained in multiple layers so that it can be performed in a single treatment, the treatment process is simplified and high quality products can be obtained stably, while the treatment work is also performed. Significantly improved. (7) Since the molten metal treating agent of the present invention can be manufactured in a state of being bound to a binder such as a curable resin when it is in the form of powder, it is easy to leak from the inside even if it is a cut piece of a small piece. Can be prevented. (8) The molten metal treatment agent of the present invention can be filled by ordinary vibration filling, but by suction-filling the powder or granules or the molten material by using a reduced pressure, it is possible to obtain a large specific gravity A molten metal treating agent having a small number of multiple structures can be manufactured at a lower cost.

[Brief description of drawings]

FIG. 1 is a schematic view showing the structure of a molten metal treatment agent obtained by the present invention.

FIG. 2 is an electron micrograph showing a metallographic structure of a product treated with a molten metal treating agent, where 1 is a metallographic structure of a product produced by the molten metal treating agent of the present invention, and 2 is a metallographic structure of a product produced by a conventional method. Show.

[Explanation of symbols]

 1 Coated metal tube 2 Additive (inoculant) 3 Additive (spheroidizing agent)

Claims (8)

[Claims] 1. Filling each space of a hollow body having a multi-layer structure containing iron or nickel as a main component with two or more kinds of additives for treating molten metal used for treating molten metal by the pouring method, and if desired, a small amount is added. A molten metal treating agent formed into a piece. 2. The molten metal treating agent according to claim 1, wherein the additive for treating molten metal is an inoculant for producing cast iron, ductile cast iron or compacted vermicular cast iron, and a spheroidizing agent or a compacted vermicular agent. 3. The treating agent according to claim 1 or 2, wherein the hollow body is a hollow double tube having airtightness, and the filling is performed by suctioning a powdery or granular additive under reduced pressure. 4. The treating agent according to claim 3, wherein the hollow tube is a steel tube or a nickel alloy tube. 5. The treating agent according to claim 1, wherein the molten metal treating agent has a specific gravity that does not substantially float on the surface of the molten metal during the molten metal treatment. 6. The treating agent according to claim 1, wherein the additive used for filling is a molten Mg alloy or ferrosilicon alloy. 7. The treating agent according to claim 1, wherein the additive is a granular Mg alloy, a ferrosilicon alloy, a calcium alloy or a fluoride thereof. 8. The treating agent according to any one of claims 1 to 7, wherein the additive is in the form of a powdery or granular additive bound with a resin.