JP2011149070A - Copper alloy and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy which has excellent hot workability, and a method for producing the copper alloy. <P>SOLUTION: The copper alloy comprises: one elemental group selected from a first elemental group composed of nickel (Ni) and silicon (Si), a second elemental group composed of zirconium (Zr) and chromium (Cr), and a third elemental group composed of titanium (Ti) and silicon (Si); at least one element selected from the group composed of tin (Sn), phosphorous (P), iron (Fe), zinc (Fe) and aluminum (Al); sulfur (S); and magnesium (Mg) of 0.01 to 0.05 mass%, and the balance copper (Cu) with inevitable impurities, and in which the change in the concentration of Mg per unit length in the casting direction is ≤0.004 mass%/m. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a copper alloy and a method for producing a copper alloy. In particular, the present invention relates to a precipitation-strengthening-type copper alloy and a method for producing the same.

  A precipitation strengthening type copper alloy such as a Cu—Ni—Si based copper alloy called a Corson alloy is a copper alloy that precipitates a specific compound by heat treatment and improves strength and conductivity. However, in precipitation-strengthening-type copper alloys having a high copper concentration (for example, about 90% by mass), the precipitation amount of the compound is large, which causes cracks during hot working.

  As a conventional method for producing a copper alloy, by adding a specific amount of B to a Cu—Ni—P—Mg alloy, crystallization or precipitation at the crystal grain boundary of the Ni—P—Mg compound is suppressed, and In addition, a method for suppressing the formation of coarse Ni—P—Mg—B compounds and P—B compounds by controlling the cooling rate during casting is known (for example, see Patent Document 1). The copper alloy described in Patent Document 1 has excellent hot workability by being formed by the above manufacturing method.

JP 2007-270314 A

  However, in general, sulfur (S) is often mixed into the copper alloy from oil used when rolling the raw material of the copper alloy, a label for identifying the product of the raw material, or the like. Since S has a low melting point and generally solidifies after Cu as a parent phase when casting a copper alloy, it is likely to segregate at grain boundaries. In the heat treatment before hot rolling the copper alloy ingot, the segregated S is melted, and a gap is generated in the crystal grain boundary. For this reason, if the copper alloy contains S having a low melting point, the grain boundary strength of the crystal is greatly reduced, and cracking may occur during hot working or the like. Therefore, in order to form a copper alloy having excellent hot workability, it is necessary to detoxify sulfur (S) having a low melting point.

  Accordingly, an object of the present invention is to provide a copper alloy having excellent hot workability and a method for producing the copper alloy.

  In order to achieve the above object, the present invention provides a first element group consisting of nickel (Ni) and silicon (Si), a second element group consisting of zirconium (Zr) and chromium (Cr), titanium (Ti), One element group selected from a third element group consisting of silicon (Si) and a group consisting of tin (Sn), phosphorus (P), iron (Fe), zinc (Zn), and aluminum (Al) Including at least one element, sulfur (S), and 0.01 mass% or more and 0.05 mass% or less of magnesium (Mg), with the balance being copper (Cu) and inevitable impurities, A copper alloy having a change in Mg concentration per unit length in the casting direction of 0.004% by mass / m or less is provided.

  Moreover, it is preferable that the said copper alloy is 1.3 mm or more and 3.0 mm or less in the average crystal grain diameter in a 60 mm area | region inside from the outline of a cross section perpendicular | vertical to the said casting direction.

  In the copper alloy, the nickel content of the first element group is 1.5 mass% or more and 9.0 mass% or less, and the silicon content of the first element group is 0.3 mass%. % To 2.5% by mass, the zirconium content of the second element group is 0.01% to 0.25% by mass, and the chromium content of the second element group is 0.00. 03 mass% or more and 0.5 mass% or less, content of the titanium of the third element group is 1.2 mass% or more and 5.1 mass% or less, and silicon (Si) content of the third element group The amount is 0.02% by mass to 0.5% by mass, the tin content is 0.01% by mass to 0.5% by mass, and the phosphorus content is 0.01% by mass to 0.45% by mass. %, The iron content is 0.01% by mass or more and 0.07% by mass or less, and the zinc content is 0.5%. % To 2.7% by mass, the aluminum content is 0.3% to 4.6% by mass, the sulfur content is 0.0001% to 0.001% by mass, 0% It is preferable to further contain 0.0001 mass% or more and 0.0001 mass% or less of hydrogen (H).

  In order to achieve the above object, the present invention provides an element group consisting of nickel (Ni) and silicon (Si), an element group consisting of zirconium (Zr) and chromium (Cr), titanium (Ti), and silicon (Si). One element group selected from the element group consisting of: at least one element selected from the group consisting of tin (Sn), phosphorus (P), iron (Fe), zinc (Zn), and aluminum (Al); Melting in a melting furnace to form a molten metal, a transferring process for transferring the molten metal from the melting furnace to a cast iron through a transfer rod, and magnesium (Mg) to the molten metal in the casting iron A method for producing a copper alloy, comprising: an addition step of continuously adding; and a casting step of casting the ingot by pouring the molten metal added with magnesium (Mg) into the mold from the casting rod and solidifying the mold. Provided That.

Moreover, the manufacturing method of the said copper alloy has the relationship between the addition speed V (g / min) of the said magnesium (Mg) in the said addition process, and the casting speed c (cm < ³ > / min) of the said ingot in the said casting process, It is preferable that 0.006 ≦ V / c ≦ 0.038.

  Moreover, in the said addition process, the manufacturing method of the said copper alloy uses the magnesium wire in which the area ratio of magnesium (Mg) in a cross section is 50% or more and 70% or less as a raw material of the said magnesium (Mg). .

  Moreover, it is preferable that the manufacturing method of the said copper alloy is 1000 or more and 25000 or less in the Reynolds number of the said molten metal in the said cast iron in the said addition process.

  Moreover, it is preferable that the oxygen concentration of the said molten metal just before adding the said magnesium (Mg) in the said addition process is 0.0015 mass% or more and 0.003 mass% or less in the manufacturing method of the said copper alloy.

  According to the copper alloy and the method for producing a copper alloy according to the present invention, it is possible to provide a copper alloy having excellent hot workability and a method for producing the copper alloy.

It is a schematic diagram of the manufacturing process of the copper alloy which concerns on embodiment of this invention. It is a figure which shows the flow of manufacture of the copper alloy which concerns on embodiment of this invention.

[Summary of embodiment]
The copper alloy according to the embodiment of the present invention is a precipitation strengthened copper alloy (for example, a Cu—Ni—Si based copper alloy called a Corson alloy, a Cu—Cr based copper alloy, a Cu—Ti based copper alloy, etc.). A first element group consisting of nickel (Ni) and silicon (Si), a second element group consisting of zirconium (Zr) and chromium (Cr), a third element group consisting of titanium (Ti) and silicon (Si). One element group selected from the group of elements (namely, a set of nickel (Ni) and silicon (Si), a set of zirconium (Zr) and chromium (Cr), and a set of titanium (Ti) and silicon (Si)) Any one of the above), at least one element selected from the group consisting of tin (Sn), phosphorus (P), iron (Fe), zinc (Zn), and aluminum (Al), and sulfur ( S) and 0.01% by mass 0.05% by mass or less of magnesium (Mg), and the balance is made of copper (Cu) and inevitable impurities, and the change in Mg concentration per unit length in the casting direction is 0.004% by mass / m or less.

(Copper alloy)
Examples of the copper alloy according to the embodiment of the present invention include a Corson alloy (Cu—Ni—Si based copper alloy) and other precipitation strengthened copper alloys (Cu—Cr based copper alloy, Cu—Ti based copper alloy, Cu-Be based copper alloy, etc.), a first material group consisting of a predetermined amount of Ni, a predetermined amount of Si, a predetermined amount of Zr, a second material group consisting of a predetermined amount of Cr, a predetermined amount of Ti, It is formed of one material group selected from a third material group made of silicon (Si), Cu as a base material, and unavoidable impurities. In addition, the range of the amount contained in the copper alloy of silicon (Si) of the first material group and silicon (Si) of the third material group is different. The copper alloy according to the present embodiment further includes at least one element selected from the group consisting of Sn, P, Fe, Zn, and Al, a predetermined amount of S, and a predetermined amount of Mg. An example of Cu is oxygen-free copper.

  Specifically, the content of the element in the copper alloy according to the present embodiment is, for example, 1.5 mass% or more and 9.0 mass% or less of nickel of the first element group, and silicon of the first element group. 0.3 mass% to 2.5 mass%, zirconium of the second element group is 0.01 mass% to 0.25 mass%, and chromium of the second element group is 0.03 mass% to 0 mass%. 0.5% by mass or less, the content of titanium of the third element group is 1.2% by mass or more and 5.1% by mass or less, and the silicon (Si) of the third element group is 0.02% by mass or more and 0.5% by mass. Mass% or less, tin is 0.01 mass% or more and 0.5 mass% or less, phosphorus is 0.01 mass% or more and 0.45 mass% or less, iron is 0.01 mass% or more and 0.07 mass% or less, zinc Is 0.5 mass% or more and 2.7 mass% or less, aluminum is 0.3 mass% or more and 4.6 mass% or less, and sulfur is 0.000. Not less than mass% 0.001 mass% or less, the balance being formed from copper and inevitable impurities.

Further, in the copper alloy according to the embodiment of the present invention, the average crystal grain size in the region of 60 mm inward from the profile of the cross section perpendicular to the casting direction is 1.3 mm to 3.0 mm (the number of crystals is, for example, 40 to 70). Pieces / cm ² ). This is because the resistance to cracking is improved when the crystal of the copper alloy is fine.

  Mg contained in the copper alloy according to the present embodiment combines with S contained in the copper alloy to form a compound of Mg and S having a melting point higher than that of S alone. Thereby, the crack of the copper alloy resulting from S contained in the copper alloy mentioned above can be suppressed. Further, in the manufacturing process, the Mg oxide generates solidification nuclei of the cast structure of the copper alloy ingot, so that the crystal of the copper alloy can be refined to improve the resistance to cracking of the copper alloy.

  S contained in the copper alloy according to the present embodiment is mixed from oil used at the time of rolling the raw material, a label for identifying the product of the raw material, etc. Present as a compound.

(Mg concentration in copper alloy)
When the concentration of Mg contained in the copper alloy is less than 0.01% by mass, a compound with S contained in the copper alloy is not sufficiently formed, and S having a low melting point remains, so that the copper alloy cracks. High risk of occurrence. On the other hand, when the concentration of Mg contained in the copper alloy exceeds 0.05% by mass, the strength of the copper alloy is excessively increased and the hot workability may be deteriorated.

  Further, in order to improve the resistance against cracking of the copper alloy by refining the crystal of the copper alloy, it is required to uniformly disperse the Mg oxide in the molten metal in which the raw material of the copper alloy is melted in the manufacturing process. . For this reason, the Mg concentration in the copper alloy according to the present embodiment is substantially uniform, and the change in the Mg concentration per unit length in the casting direction is 0.004 mass% / m or less.

(Copper alloy manufacturing method)
FIG. 1 shows an outline of a manufacturing process of a copper alloy according to an embodiment of the present invention, and FIG. 2 shows an example of a flow of manufacturing a copper alloy according to an embodiment of the present invention.

  The copper alloy ingot 30 of the copper alloy according to the present embodiment is manufactured by the copper alloy manufacturing apparatus 1. The copper alloy manufacturing apparatus 1 includes, for example, a melting furnace 10 in which a raw material containing copper and inevitable impurities and an element contained in the copper alloy ingot 30 is melted, and a raw material melted in the melting furnace 10. A casting rod 14 to which the molten metal 20 is supplied via the transfer rod 12 and a mold 18 to which the molten metal 20 that has been subjected to a predetermined treatment in the casting rod 14 is supplied. The molten metal 20 supplied to the mold 18 is cooled at the contact portion with the mold 18 to become a copper alloy ingot 30.

  Specifically, an example of the flow of manufacturing the copper alloy according to the present embodiment will be described with reference to FIG.

  First, the raw material of the copper alloy to be manufactured is prepared, and the prepared raw material is put into the melting furnace 10. For example, Ni, Si, P, Fe, and Zn are introduced into the melting furnace 10. Then, the melting furnace 10 is heated to a predetermined temperature, and the raw material is melted in the melting furnace 10 to form the molten metal 20 (melting step: step 10, hereinafter, step is referred to as “S”).

  Next, the molten metal 20 is transferred from the melting furnace 10 to the casting rod 14 via the transfer rod 12 (transfer step: S20).

  Next, the molten metal 20 is temporarily held in the casting bowl 14, and the oxygen concentration and the Reynolds number are adjusted (adjustment process: S30).

  Next, Mg is continuously added to the molten metal 20 at a predetermined speed in the casting bowl 14 (addition process: S40). The added Mg is oxidized in the molten metal 20, and Mg oxide serving as a solidification nucleus of the cast structure of the copper alloy ingot 30 is generated.

  Next, the copper alloy ingot 30 is cast by pouring the molten metal 20 from the casting iron 14 into the mold 18 and solidifying it (casting process: S50). At this time, the casting speed of the copper alloy ingot 30 is adjusted so as to satisfy the relationship (0.006 ≦ V / c ≦ 0.038) with the Mg addition speed in the addition step S40 described above.

(About Reynolds number of molten metal 20)
In adjustment process S30, the Reynolds number of the molten metal 20 in the casting iron 14 is adjusted to 1000 or more and 25000 or less. Thereby, Mg oxide can be uniformly disperse | distributed in the molten metal 20 in addition process S40.

  When the Reynolds number of the molten metal 20 is less than 1000, there is almost no flow in the depth direction of the molten metal 20 in the casting rod 14, and the Mg added in the addition step S40 does not spread uniformly throughout the molten metal 20. Therefore, the Mg concentration in the vicinity of the molten metal surface of the molten metal 20 is high, the Mg concentration in the vicinity of the bottom portion is low, and the distribution of Mg oxide in the molten metal 20 becomes uneven.

  Further, when the Reynolds number of the molten metal 20 exceeds 25,000, the molten metal 20 in the casting rod 14 becomes more turbulent, a crack occurs in the carbon-based material covering the molten metal surface, and the molten metal surface is activated. This makes it easier to take up oxygen. Therefore, the oxidation of Mg added in the addition step S40 is abnormally accelerated, and the Mg oxide in the molten metal 20 cannot generate solidification nuclei of the cast structure of the copper alloy ingot 30.

(About the oxygen concentration of the molten metal 20)
In the adjustment step S30, the oxygen concentration of the molten metal 20 in the casting bowl 14 is adjusted to 0.0015 mass% or more and 0.003 mass% or less. Thereby, in addition process S40, in order to produce | generate the solidification nucleus of the cast structure | tissue of the copper alloy ingot 30, an appropriate quantity of Mg oxide can be produced | generated in the molten metal 20. FIG.

  When the oxygen concentration of the molten metal 20 is less than 0.0015% by mass, an amount of Mg oxide necessary for generating solidified nuclei is not generated.

  Moreover, when the oxygen concentration of the molten metal 20 exceeds 0.003 mass%, excess Mg oxide is produced | generated and coarse oxidation slag is formed. Oxidized slag has a tendency to take in and subsequently agglomerate Mg oxide, and does not contribute to the formation of solidification nuclei. Moreover, there exists a possibility that oxidation slag may block the pouring of the molten metal 20 to the casting_mold | template 18 by pinching the pouring opening | mouth of the casting rod 14. FIG.

(Mg addition speed and casting speed of copper alloy ingot 30)
The addition rate of Mg in the addition step S40 and the casting rate of the copper alloy ingot 30 in the casting step S50 are controlled so that they satisfy a predetermined relationship. Thereby, an appropriate amount of Mg oxide can be formed in the molten metal 20 in order to generate solidification nuclei of the cast structure of the copper alloy ingot 30.

Specifically, the relationship between the Mg addition rate V (g / min) in the addition step S40 and the casting rate c (cm ³ / min) of the copper alloy ingot 30 in the casting step S50 described later is 0.006 ≦ V The addition rate of Mg is adjusted so as to satisfy /c≦0.038.

  When the rate of Mg addition relative to the casting speed of the copper alloy ingot 30 is too slow (V / c <0.006), Mg oxide is accumulated in the molten metal 20 and coarse oxide slag that does not contribute to the formation of solidified nuclei; Become.

  Moreover, when the addition rate of Mg with respect to the casting speed of the copper alloy ingot 30 is too fast (0.038 <V / c), the amount of Mg oxide generated per unit time becomes excessive and is too slow. This results in a coarse oxide slag that does not contribute to the formation of solidification nuclei.

(About magnesium wire)
As the raw material for Mg added in the adding step S40, a magnesium wire having an area ratio of Mg in the cross section of 50% to 70% is used. More specifically, for example, a pure oxygen having a diameter of 0.1 mm or more and 2 mm or less inside a pipe-shaped oxygen-free copper strip having an oxygen concentration of 0.0003 mass% or less and a thickness of 0.5 mm or less. A composite material of Mg and Cu filled with Mg particles is used as the magnesium wire.

  When the area ratio of Mg in the cross section in the magnesium wire is less than 50%, when the magnesium wire is added to the molten metal 20, oxygen and Mg contained in the magnesium wire react to generate Mg oxide, and Mg Cannot be appropriately added to the molten metal 20. In addition, the amount of Mg oxide produced becomes excessive, resulting in a coarse oxide slag that does not contribute to the formation of solidified nuclei.

  Moreover, when the area ratio of Mg in the cross section in the magnesium wire exceeds 70%, the amount of Mg added to the molten metal 20 at one time becomes excessive, and the Mg concentration near the molten metal surface of the molten metal 20 increases. The Mg oxide distribution in the molten metal 20 becomes non-uniform.

(Effect of embodiment)
According to the embodiment of the present invention, an appropriate amount of Mg is added to a molten metal obtained by melting a raw material of a copper alloy and combined with S to reduce low melting point materials in the copper alloy, and before hot working. Generation of cracks in heat treatment or the like can be suppressed.

  In addition, according to the embodiment of the present invention, in a molten metal obtained by melting a copper alloy raw material, an appropriate amount of Mg oxide is uniformly dispersed to generate a solidified nucleus of a cast structure of a copper alloy ingot, The resistance against cracking of the copper alloy during hot working or the like can be improved by refining the crystal of the copper alloy.

  Below, the copper alloy ingot which concerns on Examples 1-10 manufactured based on Embodiment and the copper alloy ingot which concerns on Comparative Examples 1-4 are demonstrated.

  The copper alloy ingots according to Examples 1 to 10 are manufactured according to the manufacturing conditions shown in the embodiment (the oxygen concentration and Reynolds number of the molten metal 20 in the casting rod 14 in the adjustment step S30, the Mg addition rate V in the addition step S40) , The ratio of the casting speed c of the copper alloy ingot 30 in the casting step S50, and the manufacturing step satisfying the conditions for the Mg raw material added in the adding step S40. On the other hand, the copper alloy ingots according to Comparative Examples 1 to 4 were formed by a manufacturing process that did not satisfy the manufacturing conditions described in the embodiment.

  As the copper alloy ingot according to Example 1, 2.5 mass% Ni, 0.45 mass% Si, 0.02 mass% P, 1.65 mass% Zn, and 0.035 Manufactured a copper alloy ingot containing mass% Fe, 0.00005 mass% H, 0.0005 mass% S, and 0.017 mass% Mg with the balance being Cu and inevitable impurities. did.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 1, the oxygen concentration and Reynolds number of the molten metal 20 in the cast iron 14 in adjustment process S30 were adjusted to 0.0028 mass% and 15000, respectively.

  Further, the ratio V / c of the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.01.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 60% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 2, 3.2 mass% Ni, 0.74 mass% Si, 0.23 mass% Sn, 0.03 mass% P, and 1.85 Containing 0.0% by mass of Zn, 0.049% by mass of Fe, 0.00009% by mass of H, 0.0004% by mass of S, and 0.041% by mass of Mg, the balance being Cu and inevitable impurities A copper alloy ingot consisting of

  In addition, in manufacture of the copper alloy ingot which concerns on Example 2, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0023 mass% and 23000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.03.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 64% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 3, 5.9 mass% Ni, 1.43 mass% Si, 0.17 mass% Sn, 0.02 mass% P, and 2.41 Including Zn by mass, 0.012 mass% Fe, 0.00006 mass% H, 0.0006 mass% S and 0.039 mass% Mg, the balance being Cu and inevitable impurities A copper alloy ingot consisting of

  In addition, in manufacture of the copper alloy ingot which concerns on Example 3, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0018 mass% and 17000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.03.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 52% was used as a raw material of Mg added in addition process S40.

  As the copper alloy ingot according to Example 4, 6.7% by mass of Ni, 1.85% by mass of Si, 0.2% by mass of Sn, 0.02% by mass of P, and 1.83%. Including in mass% Zn, 0.028 mass% Fe, 0.00003 mass% H, 0.0005 mass% S and 0.047 mass% Mg, the balance being Cu and inevitable impurities A copper alloy ingot consisting of

  In addition, in manufacture of the copper alloy ingot which concerns on Example 4, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0025 mass% and 7000, respectively.

  Further, the ratio V / c of the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.033.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 64% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 5, 0.35 mass% Si, 3.5 mass% Ti, 0.01 mass% P, 0.00004 mass% H, and 0.0006 A copper alloy ingot containing mass% S and 0.04 mass% Mg with the balance being Cu and inevitable impurities was manufactured.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 5, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0019 mass% and 2000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.028.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 65% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 6, 0.042 mass% Si, 4.8 mass% Ti, 0.01 mass% P, 0.66 mass% Zn, and 0.00006 A copper alloy ingot containing mass% H, 0.0003 mass% S, and 0.25 mass% Mg, with the balance being Cu and inevitable impurities was manufactured.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 6, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.003 mass% and 8000, respectively.

  Further, the ratio V / c of the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.019.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 62% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 7, 0.24 mass% Cr, 0.08 mass% Zr, 0.15 mass% Sn, 0.01 mass% P, and 0.00007 A copper alloy ingot containing mass% H, 0.0005 mass% S, and 0.03 mass% Mg, with the balance being Cu and inevitable impurities was produced.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 7, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0022 mass% and 12000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.015.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 54% was used as a raw material of Mg added in addition process S40.

  As the copper alloy ingot according to Example 7, 0.18 mass% Cr, 0.11 mass% Zr, 0.11 mass% Sn, 0.3 mass% Zn, 0.00003 A copper alloy ingot containing mass% H, 0.0004 mass% S, and 0.043 mass% Mg, with the balance being Cu and inevitable impurities was produced.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 7, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0024 mass% and 20000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.03.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 60% was used as a raw material of Mg added in addition process S40.

  As a copper alloy ingot according to Example 9, 0.4 mass% Cr, 0.16 mass% Zr, 0.25 mass% Sn, 0.01 mass% P, and 0.00009 A copper alloy ingot containing mass% H, 0.0006 mass% S, and 0.016 mass% Mg, the balance being made of Cu and inevitable impurities was manufactured.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 9, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0023 mass% and 9000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.008.

  In addition, as the Mg raw material to be added in the adding step S40, a magnesium wire having an Mg area ratio of 59% in the cross section was used.

  As the copper alloy ingot according to Example 10, 7.2 mass% Ni, 0.023 mass% Si, 0.05 mass% P, 0.057 mass% Fe, 2.4 Manufactured a copper alloy ingot containing mass% Al, 0.00004 mass% H, 0.0003 mass% S, and 0.036 mass% Mg, the balance being Cu and inevitable impurities. did.

  In addition, in manufacture of the copper alloy ingot which concerns on Example 10, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0025 mass% and 4000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.022.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 55% was used as a raw material of Mg added in addition process S40.

(Comparative Example 1)
As a copper alloy ingot according to Comparative Example 1, 3.4 mass% Ni, 0.59 mass% Si, 0.2 mass% Sn, 0.02 mass% P, 1.6 Containing 0.0% by mass of Zn, 0.039% by mass of Fe, 0.00006% by mass of H, 0.0014% by mass of S, and 0.006% by mass of Mg, the balance being Cu and inevitable impurities A copper alloy ingot consisting of

  In the production of the copper alloy ingot according to Comparative Example 1, the oxygen concentration and the Reynolds number of the molten metal 20 in the casting iron 14 in the adjustment step S30 were adjusted to 0.0037% by mass and 28000, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.003.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 40% was used as a raw material of Mg added in addition process S40.

(Comparative Example 2)
As a copper alloy ingot according to Comparative Example 2, 4.7% by mass of Ni, 0.94% by mass of Si, 0.24% by mass of Sn, 0.03% by mass of P, and 1.71 Including Zn by mass, 0.03% by mass of Fe, 0.00006% by mass of H, 0.0007% by mass of S, and 0.075% by mass of Mg, the balance being Cu and inevitable impurities A copper alloy ingot consisting of

  In addition, in manufacture of the copper alloy ingot which concerns on the comparative example 2, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0011 mass% and 1200, respectively.

  Further, the ratio V / c of the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.055.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 64% was used as a raw material of Mg added in addition process S40.

(Comparative Example 3)
As a copper alloy ingot according to Comparative Example 3, 0.41 mass% Si, 3.7 mass% Ti, 0.01 mass% P, 0.00004 mass% H, 0.0003 A copper alloy ingot containing mass% S and 0.097 mass% Mg, with the balance being Cu and inevitable impurities was produced.

  In addition, in manufacture of the copper alloy ingot which concerns on the comparative example 3, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.0012 mass% and 26000, respectively.

  Further, the ratio V / c of the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.059.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 88% was used as a raw material of Mg added in addition process S40.

(Comparative Example 4)
As a copper alloy ingot according to Comparative Example 4, 0.26 mass% Cr, 0.06 mass% Zr, 0.17 mass% Sn, 0.02 mass% P, and 0.00007 A copper alloy ingot containing mass% H, 0.0005 mass% S, and 0.15 mass% Mg, with the balance being Cu and inevitable impurities was produced.

  In addition, in manufacture of the copper alloy ingot which concerns on the comparative example 4, the oxygen concentration and Reynolds number of the molten metal 20 in the casting iron 14 in adjustment process S30 were adjusted to 0.001 mass% and 1400, respectively.

  Further, the ratio V / c between the Mg addition rate V in the addition step S40 and the casting rate c of the copper alloy ingot 30 in the casting step S50 was adjusted to 0.066.

  Moreover, the magnesium wire material whose area ratio of Mg in a cross section is 79% was used as a raw material of Mg added in addition process S40.

(Evaluation of copper alloy ingot)
For each of the copper alloy ingots according to Examples 1 to 10 and Comparative Examples 1 to 4, a change in Mg concentration per unit length in the casting direction, an area of 60 mm inward from the profile of the cross section perpendicular to the casting direction The average crystal grain size and cracks during hot working were evaluated.

  In Table 1, the evaluation result of the copper alloy ingot which concerns on Examples 1-10 and Comparative Examples 1-4 is shown.

  As shown in Table 1, the copper alloy ingots according to Examples 1 to 10 were not cracked on the surface and inside during hot rolling. On the other hand, the copper alloy ingots according to Comparative Examples 1 to 4 were cracked on the surface or inside during hot rolling.

  While the embodiments and examples of the present invention have been described above, the embodiments and examples described above do not limit the invention according to the claims. It should be noted that not all combinations of features described in the embodiments and examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 Copper alloy manufacturing apparatus 10 Melting furnace 12 Transfer rod 14 Casting rod 18 Mold 20 Molten metal 30 Copper alloy ingot

Claims (8)

First element group made of nickel (Ni), silicon (Si), second element group made of zirconium (Zr), chromium (Cr), third element group made of titanium (Ti), silicon (Si) One element group selected from
At least one element selected from the group consisting of tin (Sn), phosphorus (P), iron (Fe), zinc (Zn), and aluminum (Al);
Sulfur (S),
0.01 mass% or more and 0.05 mass% or less of magnesium (Mg);
And the balance consists of copper (Cu) and inevitable impurities,
A copper alloy having a change in Mg concentration per unit length in the casting direction of 0.004% by mass / m or less.   2. The copper alloy according to claim 1, wherein an average crystal grain size in a region 60 mm inward from a profile of a cross section perpendicular to the casting direction is 1.3 mm or more and 3.0 mm or less. The nickel content of the first element group is 1.5 mass% to 9.0 mass%, and the silicon content of the first element group is 0.3 mass% to 2.5 mass%. Hereinafter, the zirconium content in the second element group is 0.01% by mass or more and 0.25% by mass or less, and the chromium content in the second element group is 0.03% by mass or more and 0.5% by mass or less. The content of the titanium in the third element group is 1.2% by mass or more and 5.1% by mass or less, and the content of silicon (Si) in the third element group is 0.02% by mass. 0.5 mass% or less, tin content is 0.01 mass% or more and 0.5 mass% or less, phosphorus content is 0.01 mass% or more and 0.45 mass% or less, iron content The amount is 0.01% by mass or more and 0.07% by mass or less, and the zinc content is 0.5% by mass or more and 2.7% by mass. Lower, the content of said aluminum 4.6 wt% 0.3 wt% or less, the content of said sulfur is 0.001 mass% 0.0001% by mass or more,
The copper alloy of Claim 2 which further contains 0.00001 mass% or more and 0.0001 mass% or less of hydrogen (H). One element group selected from an element group consisting of nickel (Ni) and silicon (Si), an element group consisting of zirconium (Zr) and chromium (Cr), an element group consisting of titanium (Ti) and silicon (Si); Melting at least one element selected from the group consisting of tin (Sn), phosphorus (P), iron (Fe), zinc (Zn), and aluminum (Al) in a melting furnace Process,
A transfer step of transferring the molten metal from the melting furnace to a casting rod through a transfer rod;
An addition step of continuously adding magnesium (Mg) to the molten metal in the casting bowl;
A casting process for casting an ingot by pouring the molten metal added with magnesium (Mg) from the casting iron into a mold and solidifying it. The relationship between the addition rate V (g / min) of the magnesium (Mg) in the addition step and the casting rate c (cm ³ / min) of the ingot in the casting step is 0.006 ≦ V / c ≦ 0. The method for producing a copper alloy according to claim 4, which is 038.   6. The method for producing a copper alloy according to claim 5, wherein in the adding step, a magnesium wire having an area ratio of magnesium (Mg) in a cross section of 50% to 70% is used as a raw material for the magnesium (Mg).   The manufacturing method of the copper alloy of Claim 6 including the adjustment process which adjusts the Reynolds number of the said molten metal in the said cast iron to 1000 or more and 25000 or less between the said transfer process and the said addition process.   The manufacturing method of the copper alloy of Claim 7 which adjusts the oxygen concentration of the said molten metal to 0.0015 mass% or more and 0.003 mass% or less in the said adjustment process.

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