JPH0631398A - Production of active metal-containing copper alloy - Google Patents

Abstract

PURPOSE:To provide a producing method of an active metal-containing copper alloy, in which a copper alloy containing the active metal of Mg, Cr and Ti, etc., is produced in the air atmosphere and a sound ingot can be obtd. CONSTITUTION:Into molten metal flowing a trough 3 connecting an induction furnace 1 with a mold 4, the active metal wire or rod 8 is inserted. In this case, the inserting position of the wire or rod 8 is made to be positioned apart from the dropping position of the molten metal from a tapping hole 2 to the trough 3 by 200-400mm at downstream side in the molten metal flowing direction and the inserting speed is made to be >=200mm/min. Further, the molten metal depth at the inserting position of this wire or rod 8 is necessary to be 15-30mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an active metal-containing copper alloy by adding an active metal such as Mg, Cr and Ti to molten copper or copper alloy to produce an active metal-containing copper alloy.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view showing a conventional method for producing an active metal-containing copper alloy.

The crucible type induction furnace (casting furnace) 1 induction-heats an active metal-added copper alloy melt 6 charged inside the crucible-type induction furnace 1 and holds it at a predetermined temperature. Above the induction furnace 1 is a furnace lid 5
Is provided. The molten metal 6 in the induction furnace 1 drops from the tap hole 2 into the gutter 3 and is supplied into the mold 4 attached to the semi-continuous casting apparatus through the gutter 3.

The mold 4 has, for example, an opening at the bottom thereof, and a bottom block 7 is arranged so as to fit into this opening. The bottom block 7 is attached to the semi-continuous casting apparatus and moves downward as the molten metal 6 poured into the mold 4 solidifies.

Conventionally, when producing an active metal-containing copper alloy, the composition of the molten metal 6 is adjusted by adding an active metal such as Mg to the molten metal 6 of copper or copper alloy in the induction furnace 1. Then, the molten metal 6 is supplied to the mold 4 through the gutter 3 and solidified to obtain an ingot.

By the way, assuming that the induction furnace 1 and the gutter 3 are in the atmosphere, the molten metal 6 is exposed at the tap hole 2 and the molten metal 6 flows from the induction furnace 1 to the gutter 3 at the same time. Is relatively large, air is entrained in the molten metal 6 and M
The active metals such as g, Cr and Ti are oxidized and lost, and the oxide is injected into the mold 4 to cause many oxide entrapment defects on the surface of the ingot. Therefore, continuous casting becomes impossible.

Therefore, conventionally, the casting of the active metal-containing copper alloy has been carried out in a facility which is hermetically sealed with an inert gas.

[0008]

However, in the above-mentioned conventional method for producing an active metal-containing copper alloy, a facility sealed with an inert gas atmosphere is required.
It has the drawback of being extremely complicated. In addition, there is a drawback in that a facility whose atmosphere is sealed with an inert gas is required and the active metal is often oxidized and lost, so that the production cost of the active metal-containing copper alloy is high.

When casting an Al alloy, M is poured into the molten Al or Al alloy melt in the gutter between the casting furnace and the mold.
There is a method of adding an active metal such as g. In this way, when an active metal is added to the gutter connecting the casting furnace and the mold, the oxidation loss of the active metal and the formation of oxides are suppressed without using an atmosphere-sealed facility with an inert gas. You can However, when this method is applied to a copper alloy, there are the following problems.

That is, the temperature of the molten aluminum is relatively low at 700 to 750 ° C, whereas the temperature of the molten Cu is 1200 to 1250 ° C.
And high. Therefore, the active metal in the Cu melt is Al
It is more likely to be oxidized than in the case of. Further, in the case of Al alloy, a substance (for example, Al-
Since the density of Ti-B) is higher than that of molten Al,
Gravity segregation is unlikely to occur, whereas in the case of Cu alloy,
Since the density of active metals such as Mg and Ti is lower than the density of Cu, gravity segregation easily occurs. Therefore, the method of adding an active metal in Al cannot be directly applied to Cu.

The present invention has been made in view of the above problems, and it is not necessary to seal the casting furnace, the gutter, and the like with an inert gas atmosphere, and a sound ingot can be obtained. An object of the present invention is to provide a method for producing an active metal-containing copper alloy that can reduce the production cost of the copper alloy.

[0012]

The method for producing an active metal-containing copper alloy according to the present invention comprises a wire or rod of active metal in a molten metal of copper or copper alloy flowing in a gutter connecting a casting furnace and a mold. In the method for producing an active metal-containing copper alloy for producing a copper alloy containing an active metal by continuously inserting, the wire or the rod is in the direction of flow of the molten metal from the molten metal dropping position from the casting furnace to the gutter. 2 downstream
Insert it into the melt at a distance of 00 to 400 mm,
Further, the molten metal depth at the wire or rod insertion position is 15 to 30 mm, and the insertion speed of the wire or rod into the molten metal is 200 mm / min or more.

[0013]

The present inventors conducted various experimental studies in order to produce an active metal-containing copper alloy in the atmosphere. As a result, when inserting the wire or rod of the active metal into the molten metal flowing in the gutter connecting the casting furnace and the mold, the insertion position, the insertion speed and the depth of the molten metal at the insertion position are set within a predetermined range. As a result, it was found that the active metal can be prevented from being oxidized and segregated by gravity, and a sound ingot can be obtained. The present invention has been made based on such experimental results.

That is, in the present invention, the active metal-containing copper alloy is manufactured by continuously inserting the wire or rod of the active metal into the molten copper or copper alloy flowing in the gutter. In this case, in order to prevent uneven distribution of the active metal due to gravity, the wire or rod insertion position is located near the position where the molten metal falls from the casting furnace into the trough (hereinafter referred to as the molten metal dropping portion). However, when the distance between the insertion position of the wire or rod and the molten metal drop portion is less than 200 mm, gravity segregation is reduced, but the dance (vibration) of the molten metal surface increases the loss of oxidation of the active metal. On the other hand, the distance between the insertion position of the wire or rod and the molten metal drop part is 4
If it exceeds 00 mm, gravity segregation becomes large. Therefore, it is necessary that the insertion position of the wire or rod is separated by 200 to 400 mm downstream from the molten metal drop portion in the molten metal flow direction.

The depth of the molten metal at the position where the wire or rod is inserted into the molten metal must be 15 to 30 mm. When the depth of the molten metal at the wire or rod insertion position is less than 15 mm or more than 30 mm, gravity segregation becomes large. Therefore, the depth of the molten metal at the wire or rod insertion position must be 15 to 30 mm.

Further, when the insertion speed of the wire or rod into the molten metal is less than 200 mm / min, the active metal burns on the surface of the molten metal, and the addition yield of the active metal is remarkably reduced. For this reason, it is necessary that the insertion speed of the wire or rod into the molten metal be 200 mm / min or more.

In the present invention, the active metal is added to the molten copper or copper alloy under the above-mentioned conditions, so that the oxidation loss of the active metal can be suppressed and the production of oxides is remarkably reduced, so that the ingot surface Oxide entrapment defects can also be avoided. Moreover, since the atmosphere sealing by the inert gas is not necessary and the amount of loss of oxidation of the active metal is drastically reduced, the production cost of the active metal-containing copper alloy can be reduced.

[0018]

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

FIG. 1 is a sectional view showing a method of manufacturing an active metal-containing copper alloy according to an embodiment of the present invention. This embodiment is different from the conventional one in that the addition method of the active metal is different, and other configurations are basically the same as the conventional one.
In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

The induction furnace 1 induction-heats the molten metal 6 of copper or copper alloy charged inside and holds it at a predetermined temperature. The molten metal 6 drops from the molten metal outlet 2 of the induction furnace 1 into the gutter 3 and is supplied to the mold 4 through the gutter 3.

In this embodiment, the active metal is added to the molten metal 6 by inserting the wire or rod 8 of the active metal into the molten metal 6 flowing through the gutter 3. In this case, the distance L from the dropping point of the molten metal 6 to the insertion position of the wire or rod 8 is 200 to 400 mm. The molten metal depth at the insertion position of the wire or rod 8 is 15 to 30 mm, and the insertion speed of the wire or rod 8 into the molten metal 6 is 200 mm / min or more.

In the present embodiment, the active metal-containing copper alloy can be manufactured while suppressing the oxidation loss of the active metal without sealing the atmosphere with an inert gas. In addition, in this example, gravity segregation of the additive element (active metal) and combustion of the active metal can be suppressed, and a sound ingot can be obtained.

Next, the results of investigating the relationship between the insertion rate of the active metal wire or rod into the molten metal and the addition yield will be described.

FIG. 2 is a graph showing the relationship between the abscissa axis and the Mg wire or rod insertion speed and the ordinate axis of the Mg addition yield. As is clear from FIG. 2, when the Mg wire or rod insertion speed is less than 200 mm / min, the Mg addition yield is as low as 65% or less. Therefore, the insertion speed of the active metal into the molten metal should be 200 mm / min or more.

Next, the result of actually producing an active metal-containing copper alloy ingot by the method shown in FIG. 1 and evaluating the quality thereof will be described in comparison with a comparative example.

A Cu-Mg alloy ingot having a length of 4000 mm was produced by using a crucible type induction furnace having a capacity of 8 tons, a gutter, a semi-continuous casting machine and a mold (width: 550 mm, thickness: 150 mm). .
The amount of Mg added, the target amount of Mg, and the position of addition of Mg are shown in Table 1 below. However, in Example 2, Comparative Examples 3, 4, and 5, two Mg rods having a diameter of 11 mm were bundled and the rod bundle was inserted into the molten metal flowing in the gutter at an insertion speed of 920 mm / min. Further, in Example 3, three Mg rods each having a diameter of 11 mm were bundled, and this rod bundle was placed in a molten metal flowing in a gutter for 1225.
Insertion was performed at an insertion speed of mm / min. Further, in Example 1, one Mg rod having a diameter of 11 mm was inserted into the melt flowing in the gutter at an insertion speed of 305 mm / min.

Then, the Mg content of each ingot obtained in these Examples and Comparative Examples was analyzed. Further, the degree of inclusion of oxide and the degree of pinhole in each ingot were also examined.
The results are shown in Table 2 below.

[0028]

[Table 1]

[0029]

[Table 2]

As is clear from Table 2, in the ingots of Examples 1 to 3, the loss amount of Mg was small, and the Mg analysis value and the Mg target amount were substantially the same. Further, these ingots have no oxide entrainment and pinholes, and the ingots are excellent in soundness.

On the other hand, in each of Comparative Examples 1 and 2 in which Mg was added to the molten metal in the induction furnace, the loss of Mg oxidation was severe, and many oxide entrainments and pinholes were generated. Also, M
Comparative Example 3 in which the g addition position is close to the falling portion is Comparative Examples 1 and 2.
Although not so much, the loss of Mg was large and oxide entrapment and pinholes occurred. Further, in Comparative Example 4 in which the Mg rod insertion position is far from the falling portion and Comparative Example 5 in which the depth of the molten metal at the Mg rod insertion position is deep, M is
The weight segregation of g was large.

[0032]

As described above, in the present invention,
Since the wire or rod of the active metal is inserted into the molten copper or copper alloy flowing under the gutter that connects the casting furnace and the mold under the specified conditions, the casting equipment is activated even if the atmosphere is not sealed with an inert gas. It is possible to suppress metal oxidation and oxide entrainment, and to obtain a sound inactive metal-containing copper alloy ingot. Further, in the present invention, it is not necessary to seal the casting equipment and the like with an inert gas and the oxidation loss of the active metal is suppressed, so that there is an effect that the production cost of the active metal-containing copper alloy can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method for manufacturing a copper alloy containing an active metal according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the Mg insertion rate and the Mg addition yield.

FIG. 3 is a cross-sectional view showing a conventional method for producing a copper alloy containing active metal.

[Explanation of symbols]

 1; induction furnace 2; tap hole 3; gutter 4; mold 5; furnace lid 6; molten metal 7; bottom block 8; wire or rod

Claims (1)

[Claims] 1. An activity for producing a copper alloy containing an active metal by continuously inserting a wire or rod of an active metal into a molten metal of copper or a copper alloy flowing in a gutter connecting a casting furnace and a mold. In the method for producing a metal-containing copper alloy, the wire or rod is 200 to 40 downstream from the position where the molten metal falls from the casting furnace to the gutter.
It is inserted into the molten metal at a position 0 mm apart, and the molten metal depth at the wire or rod insertion position is 15 to
A method for producing an active metal-containing copper alloy, which has a length of 30 mm and an insertion speed of the wire or rod into a molten metal of 200 mm / min or more.