JPS6237683B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a spheroidizing method.

The most common conventional method for manufacturing spheroidal graphite cast iron is to place alloy ingots, alloy grains, or alloy powder in a ladle for spheroidization treatment, and then process the molten cast iron by flowing it into the ladle. It's a method. In addition to this,
Recently, a method has been used in which alloy grains or alloy powder for spheroidizing treatment are placed in a mold, molten cast iron is poured, and then the molten metal is spheroidized within the mold.

However, in the former method of spheroidizing the molten metal in a ladle, the spheroidization process cannot be performed immediately before pouring the molten metal into the mold, and after the spheroidization process,
Because it takes time to pour the molten metal, the spheroidized material (for example, Mg alloy) sometimes disappears, or the so-called fading phenomenon occurs. In addition, since inoculation must be performed, there are disadvantages in that there is a large amount of dross, large sink marks, and poor castability.

Also, in the latter method of spheroidizing in the mold,
Since the spheroidizing alloy does not completely dissolve into the molten cast iron, it has the disadvantage that so-called segregation, in which spheroidized portions and non-spheroidized portions are formed, is likely to occur.

In order to improve the above-mentioned drawbacks, the present applicant first developed a spheroidizing method (Japanese Patent Application No. 161575/1983) in which a spheroidized material is melted and the molten metal reacts with molten cast iron.
However, since this method exposes the molten metal to the air during the reaction, rapid reactions may occur depending on the content of the spheroidized metal in the spheroidized material. It had the disadvantage of being dangerous.

In order to solve these drawbacks, the present invention has the following features:
This is a spheroidizing method in which the melting furnace or ladle in which the spheroidized material is melted and the area where the molten metal reacts with the molten cast iron are kept inert.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is a ladle for molten cast iron, 2 is a melting furnace or ladle for spheroidizing molten metal, 3 is a mold, and 3a is a pouring spout thereof.

In the present invention, as shown in FIG. 1, a ladle 1 for molten cast iron and a melting furnace or ladle 2 for pouring the molten spheroidized material into the ladle 1 are covered by a casing 4. By supplying an inert gas into the casing 4 as shown by the arrow, the area where the molten spheroidized material and molten cast iron react is covered with inert gas, and the atmosphere is covered with inert gas. do.

In this way, the molten cast iron and the spheroidized molten metal react during pouring, and the molten cast iron is spheroidized.

In addition, as shown in Fig. 2, the area between the melting furnace or ladle 2 in which the spheroidized material is melted by the casing 4 and the mold 3 into which the molten metal is poured is covered with an inert cloth. Alternatively, the reaction may be performed.

The cylinder 5 shown in FIG. 2 has a casing 4 that gets in the way when the mold 3 is moved continuously or intermittently so that the next mold 3 to be poured is under the melting furnace, ladle 2, etc. If this happens, temporarily pull up the casing 4 and move the mold 3, then
This is to cover the area around the mold again.

Furthermore, Fig. 3 shows the pouring port 3b for pouring molten cast iron into the mold.
A sprue 3c for the molten spheroidized material is provided, and the molten cast iron is poured from the ladle 1 into the mold 3 through the pouring port 3b, and the molten spheroidized material is poured from the melting furnace or the ladle 2 into the pouring port. 3c into the mold 3, and the spheroidizing process is performed in the mold.In this case, the melting furnace or ladle 2 in which the spheroidized material is melted, and the mold 3 into which the molten metal is poured. Casing 4
will be established.

Although Figs. 1 and 2 show a melting furnace for molten spheroidized material and a type in which the ladle 2 is suspended from a hook 6, this is similar to the ladle 1 for molten cast iron shown in Fig. 3. Needless to say, it can also be placed on the floor.

Since the method of the present invention is as described above, it is safe because it does not cause a rapid reaction during the reaction, and it also reduces fading because it is covered with an inert material until the reaction occurs. Excellent results can be obtained.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams of the method of the present invention, respectively. 1... Ladle for molten cast iron, 2... Melting furnace or ladle for spheroidizing molten metal, 3... Mold, 3a... Pouring spout, 3
b...Pouring port for molten cast iron, 3c...Pouring port for spheroidizing molten metal, 4...Casing, 5...Cylinder, 6
...Futsuku.

Claims (1)

[Scope of Claims] 1. A spheroidizing method in which the melting furnace or ladle in which the spheroidized material is melted and the vicinity where the molten metal reacts with the molten cast iron are kept inert. 2. A spheroidizing method in which there is an inert atmosphere between the melting furnace or ladle in which the spheroidized material is melted and the mold into which the molten metal is poured. 3. A spheroidizing method in which the melting furnace or ladle in which the spheroidized material is melted and the inside of the mold into which the molten metal is poured are kept inert.