JP2862677B2 - Copper alloy melting and casting methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting and casting a copper alloy to which a component element having a melting point higher than that of copper is added.

[0002]

2. Description of the Related Art Conventionally, as a method of melting and casting a copper alloy, a method of blending a raw material of a copper raw material and an alloy component element in a state of a cold lump and putting the raw material into a melting furnace, and melting and casting, or a method of melting and casting the copper raw material After maintaining the temperature of the molten copper in the melting furnace or the receiving furnace at 100 ° C or more higher than the copper melting point, a solid alloy component element raw material was added to adjust the target component composition. Thereafter, a casting method or the like is usually performed, and component elements having a melting point higher than the melting point of copper (eg, iron, cobalt,
A similar method is employed for melting and casting a copper alloy to which chromium or the like (hereinafter, referred to as a high melting point element) is added.

[0003]

By the way, when the copper alloy obtained by adding the high melting point element is melted and cast by the above-described copper alloy melting and casting method, the high melting point element is uniformly dispersed in the molten copper. It takes a lot of time to dissolve. Moreover,
Even if dissolved, undissolved elements often remain. In addition, since the temperature of the molten copper is maintained at a temperature higher than the casting temperature for a long time to promote the homogenization of the high-melting element, a large amount of hydrogen gas is occluded in the molten metal, making it difficult to obtain a sound ingot.

[0004] As described above, in the conventional method of melting and casting a copper alloy to which a high melting point element is added, the copper melt must be maintained at a relatively high temperature for a long time, which is not economical in terms of energy. In addition, there are problems that the high melting point element remains undissolved in the molten copper and that a large amount of hydrogen gas is absorbed in the molten metal.

The present invention has been made in view of the above problems, and an object thereof is to provide an improved ingot for obtaining a sound ingot with no undissolved high melting point element and a small amount of stored hydrogen gas. It is an object of the present invention to provide a method for melting and casting a copper alloy to which a high melting point element is added.

[0006]

In order to achieve the above object, a method for melting and casting a copper alloy according to the present invention comprises the steps of: melting a molten metal containing copper as a main component; and a component element having a melting point higher than the melting point of copper. (Melting element) and a molten metal in a separate furnace, and before casting, a molten metal containing copper as a main component is poured and mixed with the molten metal of a high melting element to adjust to a target component composition and then cast. .

[0007]

According to the present invention, copper and the high melting point element, which are the main components of the copper alloy, are melted in separate melting furnaces. It is possible to mix both molten metals after melting, so that the desired composition of the components is obtained.Therefore, the high melting point element is added in a state where the molten copper is completely melted without holding it at a high temperature for a long time. In addition, since it is not necessary to maintain the copper melt at a high temperature for a long time, occlusion of hydrogen gas can be reduced. However, by the subsequent casting,
It is possible to obtain a sound ingot with no undissolved high melting point element and a small amount of stored hydrogen gas.

Further, since copper and the high melting point element are melted in separate melting furnaces, it is not necessary to maintain the copper melt at a high temperature for a long time, and the melting of the high melting point element depends on the respective physical properties. An optimal compact melting furnace, for example, a high-frequency induction furnace or a gas furnace can be used as appropriate, and a copper alloy melt can be obtained economically with energy.

[0009]

Embodiments of the present invention will be described below. In the present example, each copper alloy having the content ratio of the high melting point elements (iron, nickel, and cobalt) shown in Table 1 was melted and cast by the following procedure to obtain an ingot.

First, a molten copper is obtained by using a small electric furnace with electrolytic copper and copper scrap as raw materials. At this time, the temperature of the molten copper is maintained at a temperature approximately 50 ° C. higher than the liquidus line in the content ratio of the high melting point element shown in Table 1 (shown as a molten metal holding temperature in Table 1). Next, into this molten copper, a molten metal of a high melting point element of iron, nickel or cobalt dissolved in another high-frequency induction furnace was poured so as to have a content shown in Table 1, and other components such as deoxidation were added. Add the remaining electrolytic copper within 5 minutes to correct the casting temperature. The obtained molten alloy was cast into a book mold having a width of 85 mm, a thickness of 50 mm and a height of 200 mm. In this manner, ingots of each alloy composition shown in Table 1 were obtained.

[0011]

[Table 1]

On the other hand, as a comparative example, a raw material consisting of electrolytic copper and copper scrap mixed with the same composition as each of the copper alloys shown in Table 1 and a solid-state high-melting element was charged into a small electric furnace and the molten metal shown in Table 1 was obtained. After melting at the holding temperature, after adding other components such as deoxidation, and further adjusting the casting temperature,
The obtained molten alloy was cast into a book mold having a width of 85 mm, a thickness of 50 mm and a height of 200 mm.

The cross-sectional microstructures of the ingot obtained by the above-described method of the present invention and the ingot obtained by the comparative method are observed, and the undissolved material of the high melting point element is investigated. The condition was investigated. In addition, surface analysis was performed using each XMA. Table 2 shows the results of the investigation of undissolved materials and the state of occlusion of hydrogen gas. Table 1 shows the results of XMA surface analysis of iron of sample No. 2 (magnification: × 1000). ).

[0014]

[Table 2]

As is apparent from Table 2, in the copper alloy ingot obtained by the method of the present invention, the solid solution of the high melting point element in the copper matrix is complete, and an unsolid solution having a size of 1 μm or more is recognized. I couldn't. No.1 hydrogen storage condition
And No.5 sample showed 0.5pp each.
m, 0.3 ppm, a small amount, it was a sound ingot. On the other hand, in the copper alloy ingot obtained by the comparative method, the solid solution of the high melting point element in the copper matrix is incomplete, and any copper alloy has an unsolid solution having a size of about 10 μm to about 20 μm. Was found in large quantities. The hydrogen gas storage state is 4.2p each.
At extremely high amounts of pm and 3.8 ppm, the soundness of the ingot was poor.

As is apparent from FIG. 1, in the copper alloy ingot obtained by the method of the present invention, Fe in the ingot is uniformly distributed at 1 μm or less. In the ingot, a large number of unsolidified coarse Fe is recognized.

[0017]

As described above, according to the method for melting and casting a copper alloy according to the present invention, the copper alloy is melted without leaving undissolved high melting point elements and without increasing the amount of hydrogen gas absorbed. In addition, a sound ingot free of undissolved high melting point elements and having a small amount of stored hydrogen gas can be obtained.

[0018]

[Brief description of the drawings]

1] Fig. 1 (A), gold by XMA iron present invention method
Genus organization chart, FIG. 1 (B), a metal by XMA iron comparison method
It is an organization chart.

Claims (1)

(57) [Claims] 1. A method for melting and casting a copper alloy by adding a component element having a melting point higher than the melting point of copper, comprising: a molten metal containing copper as a main component; and a component element having a melting point higher than the melting point of copper. Melt in a separate furnace, and before casting, inject and mix a melt of a component element with a melting point higher than the melting point of copper into the melt containing copper as the main component, adjust to the target component composition, and then cast. Melting and casting methods for copper alloys.