JP2010149168A - Method for producing copper alloy ingot, and method for adding active element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a copper alloy ingot which can suitably add active elements to a copper alloy, and to provide a method for adding active elements. <P>SOLUTION: The method for producing the copper alloy ingot comprises: a first active element addition step where a first active element addition material containing an active element is added to a melting furnace containing the molten metal of the main raw material of a copper alloy ingot in the air to form a molten metal containing the active element; a tapping step where the molten metal containing the active element is tapped from the melting furnace to a tundish; and a second active element addition step where a second active element addition material containing an active element is added to the molten metal containing the active element tapped into the tundish in the air. The first active element addition material and the second active element addition material each contain melting point reduction elements making the melting points of the first active element addition material and the second active element addition material lower than the melting points of the single substances of the active elements, and oxidation inhibition elements inhibiting the oxidation of the active elements. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a copper alloy ingot and a method for adding an active element. In particular, the present invention relates to a method for producing a copper alloy ingot to which an active element is added and a method for adding the active element.

  As a conductive material constituting a connector, a lead frame, etc., a copper alloy having excellent electrical conductivity, thermal conductivity, etc. is used. In recent years, with the miniaturization of electronic components, further improvements in the strength and electrical conductivity of copper alloys have been demanded. For example, for the purpose of improving the function of a copper alloy, development of a copper alloy in which an active element is added to the copper alloy is being developed.

  Conventionally, a molten copper melted in a melting furnace is adjusted to a predetermined temperature, and this molten metal is passed through the molten metal path from the outlet of the melting furnace to the inlet of the mold, and at a predetermined position in the molten metal path, copper or copper There is known a casting method for casting a copper alloy to which an active element is added by continuously introducing a wire made of an active element coated with an inactive element except for (see, for example, Patent Document 1).

  According to the copper alloy casting method described in Patent Document 1, the active element is not added directly into the melting furnace, so that the oxidation of the active element is suppressed even if the active element is added to the molten metal and dissolved in the atmosphere. it can.

JP 2000-317580 A

  However, in the copper alloy casting method described in Patent Document 1, the temperature of the molten metal discharged from the melting furnace is lower than the temperature of the molten metal in the melting furnace. Due to clogging of unmelted residue in the hot water nozzle, problems such as casting stoppage may occur.

  Therefore, the objective of this invention is providing the manufacturing method of the copper alloy ingot which can add an active element appropriately to a copper alloy, and the addition method of an active element.

  In order to achieve the above object, the present invention adds a first active element additive containing an active element to a melting furnace having a molten metal as a main raw material of a copper alloy ingot in the atmosphere, and contains the active element. The first active element adding step for forming the molten metal, the hot water discharging step for discharging the molten metal containing the active element from the melting furnace to the tundish, and the molten metal containing the active element discharged in the tundish include the active element. A second active element addition step of adding the second active element additive in the atmosphere, and each of the first active element additive and the second active element additive is higher than the melting point of the active element alone. There is provided a method for producing a copper alloy ingot including a melting point lowering element that lowers the melting point of one active element additive and a second active element additive, and an oxidation inhibiting element that suppresses oxidation of the active element.

  In the method for producing a copper alloy ingot, the active element may be Mg, the melting point lowering element may be Cu, and the oxidation inhibiting element may be Ca.

  Further, in the method for producing a copper alloy ingot, the first active element additive and the second active element additive are each Mg alloys, and the Mg alloy is composed of 15 mass% or more and 50 mass% or less of Cu. 1 mass% or more and 5 mass% or less of Ca, and the remainder may consist of Mg and inevitable impurities.

  Moreover, the manufacturing method of the said copper alloy ingot WHEREIN: When the quantity of the active element contained in the copper alloy ingot to manufacture is made into a target quantity, the 1st active element addition process is the quantity used as a% of a target quantity The first active element additive containing the active element is added, and the second active element adding step adds the second active element additive containing the active element in an amount of b% or less of the target amount, a and b may satisfy b = 100−a (20 ≦ a ≦ 40).

  In the method for producing a copper alloy ingot, the first active element additive may be an alloy ingot, and the second active element additive may be a wire.

  Moreover, as for the manufacturing method of the said copper alloy ingot, the wire may have a wire diameter of 3.0 mm or less in diameter.

  In order to achieve the above object, the present invention adds a first active element additive containing an active element to a melting furnace that holds in the atmosphere a melt of the main raw material in which the main raw material of the copper alloy ingot is melted. Then, the first active element addition step for forming the molten metal containing the active element, the molten metal containing the active element is discharged from the melting furnace to the tundish, and the molten metal containing the active element discharged from the tundish is obtained. A second active element addition step of adding a second active element additive containing an active element in the atmosphere, wherein the first active element additive and the second active element additive are respectively active elements An active element addition method is provided that includes a melting point lowering material that lowers the melting point of the first active element additive and the second active element additive than the melting point of the simple substance, and an oxidation inhibitor that suppresses oxidation of the active element. The

  According to the method for producing a copper alloy ingot and the method for adding an active element according to the present invention, it is possible to provide a method for producing a copper alloy ingot capable of appropriately adding an active element to a copper alloy and a method for adding an active element.

[Embodiment]
FIG. 1 shows an example of the flow of manufacturing a copper alloy ingot according to the present embodiment.

  First, the main raw material which comprises a copper alloy ingot is thrown into a melting furnace, and a main raw material is melt | dissolved in air | atmosphere by applying heat to a main raw material. As a result, a melt of the main raw material in which the main raw material is dissolved is formed (main raw material melting step: step 10; hereinafter, step is referred to as “S”). Here, the main raw material in the present embodiment is a metal material containing an element constituting the copper alloy ingot, for example, copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, iron raw material, zinc It is a metal material containing a raw material, a phosphorus raw material, etc., and is a metal material that does not substantially contain a material containing an active element to be described later (it is not excluded that a trace amount of an active element is inevitably included).

  Subsequently, a coating material is added to the melting furnace having the main raw material melt in the atmosphere to form a coating layer that prevents the main raw material melt from directly contacting the air (coating step: S20). ). As the coating material, a material mainly composed of carbon can be used. For example, charcoal, carbon powder, desalco (a kind of coke), or the like can be used.

  Next, an alloy material as a first active element additive containing an active element is added in the atmosphere to the molten main material whose surface is coated with a coating layer (first active element addition step: S30). ). Thereby, a melting furnace has a molten metal containing an active element. Here, the active element is at least one active element selected from the group consisting of Mg, Ti, Zr, Cr, Al, Si, and Fe, for example. In this embodiment, when added to copper, the crystal structure of the copper alloy is refined, the hot workability of the copper alloy is improved, and the conductivity of the copper alloy is less decreased with respect to the concentration of the active element added. It is preferable to use Mg which is an element.

  The alloy material as the first active element additive includes a melting point lowering element that lowers the melting point of the first active element additive than the melting point of the active element alone, and an oxidation inhibitory element that suppresses the oxidation of the active element. It is formed including. Examples of the melting point lowering element include Cu, Fe, Al and the like. In the present embodiment, since a copper alloy ingot is manufactured, it is preferable to use Cu. In addition, as the oxidation inhibiting element, an element that is more easily oxidized than the active element can be used, and for example, Ca can be used. Further, the first active element additive can be formed in a lump shape.

  As an example, the first active element additive is a massive Mg—Cu—Ca alloy lump, which is 15% by mass to 50% by mass Cu and 1% by mass to 5% by mass. Ca and the balance are Mg and inevitable impurities. Since this alloy lump contains Cu as a melting point lowering element of 15 mass% or more and 50 mass% or less with respect to Mg, it has a melting point lower than the melting point of Mg alone (Mg melting point: 650 ° C.). Note that when the Cu content of the Mg—Cu—Ca alloy ingot changes within a range of 15% by mass to 50% by mass, the melting point of the Mg—Cu—Ca alloy ingot is 485 ° C. (the Cu content is 15% by mass). The melting point when the Cu content is 50% by mass). That is, when the Cu content of the Mg—Cu—Ca alloy lump is changed from 50% by mass to 15% by mass, the melting point of the Mg—Cu—Ca alloy lump is the melting point (650 when the Cu content is 50% by mass). Lower than the melting point (485 ° C.) when the Cu content is 15 mass%.

  Moreover, this alloy lump contains Ca as an oxidation inhibiting element. Therefore, when an Mg—Cu—Ca alloy lump is added to the molten metal, it is suppressed that Mg is explosively oxidized due to sacrificial oxidation of Ca. Thereby, generation | occurrence | production of the spark accompanying explosive oxidation of Mg is suppressed.

  Subsequently, the molten metal containing the first active element additive is poured out into the tundish (pour-out step: S40). Then, the surface of the molten metal containing the first active element additive discharged from the tundish is coated with a coating material. In this state, the molten metal containing the first active element additive is held for a predetermined time (holding step: S50). As the coating material in the holding step, for example, charcoal, carbon powder, desalco (a kind of coke) or the like can be used.

  Next, the second active element additive is continuously added in the atmosphere to the molten metal containing the first active element additive (second active element addition step: S60). The second active element additive is formed from the same material as the first active element additive. Further, the second active element additive is formed to have a form different from that of the first active element additive, for example, a wire. In the present embodiment, the second active element additive is a linear Mg—Cu—Ca alloy wire, and the alloy wire contains 15% by mass to 50% by mass of Cu and 1% by mass. The amount of Ca is 5% by mass or less and the balance is Mg and inevitable impurities. For example, the wire is formed with a diameter of 3.0 mm or less.

  Here, it is preferable that the addition amount of each of the first active element additive and the second active element additive is as follows. That is, when the amount of active element contained in the copper alloy ingot to be manufactured is set as a target amount, the first active element additive contains an amount of active element that is a% of the target amount and the second amount. The active element additive preferably contains an active element in an amount that is not more than b% of the target amount, and at least the amount of the active element contained in the first active element additive is the second active element added. The values of a and b are preferably smaller than the amount of active elements contained in the material. For example, it is preferable to satisfy the relational expression b = 100−a (where 20 ≦ a ≦ 40).

  Subsequently, the second active element additive is added, and a cast alloy melted with the second active element additive is poured into the mold to cast a copper alloy ingot (casting step: S70). Thereby, the copper alloy ingot manufactured by the manufacturing method of the copper alloy ingot which concerns on this Embodiment can be obtained. According to the method for producing a copper alloy ingot according to the present embodiment, for example, the active element composition is 80% or more regardless of the composition of the first active element additive and the second active element additive. The active element addition yield (addition yield refers to the ratio of the amount of active element contained as an active element in the copper alloy ingot to the amount of added active element) while maintaining the copper alloy ingot A copper alloy ingot is produced in which the concentration of the active element in the direction along the casting direction is kept substantially constant.

(Effect of embodiment)
According to the method for producing a copper alloy ingot according to the present embodiment, the addition of the active element is made into a two-stage method of the first active element addition step and the second active element addition step, and the first activity is added. Since the amount of the active element input in the element addition step is smaller than the amount of the active element input in the second active element addition step, the entire amount of the active element contained in the copper alloy ingot to be manufactured is input to the melting furnace. Compared to the case, the amount of the active element that is oxidized while the molten metal flows from the melting furnace to the mold can be reduced. Therefore, the generation of oxides of active elements can be reduced, so that the flowability of the molten metal can be improved, and casting defects caused by the oxide being caught in the ingot can be reduced. As a result, the quality of the ingot and the castability can be maintained as compared with the case where the entire amount of the active element is added to the melting furnace. Furthermore, since the active element is added stepwise, for example, compared to the case where the active element is first added to the molten metal in a tundish, it is possible to suppress the rise of the concentration of the active element in the initial casting portion of the ingot. , Can improve product yield.

  Further, according to the method for producing a copper alloy ingot according to the present embodiment, since the generation of oxides of active elements can be reduced as described above, the molten metal containing the active elements is transferred to the transfer tub, casting tub, tundish, mold Oxidation slag produced by the active element oxidizing as it moves to can be reduced. Thereby, it can suppress that the quantity of the active element in the direction along the casting direction of an ingot reduces. That is, according to the method for producing a copper alloy ingot according to the present embodiment, since the active element is gradually added to the molten metal, the active element is oxidized and gradually decreases as the molten metal advances from the melting furnace to the mold. Compared to the case where the entire amount of active element is introduced into the melting furnace, which is a manufacturing method, even if the molten metal advances from the melting furnace to the mold, the decrease in the amount of active element in the direction of the molten metal can be suppressed. .

  In addition, according to the method for producing a copper alloy ingot according to the present embodiment, the generation of oxidized slag can be reduced, thereby suppressing the generation of oxidized slag aggregates. Clogging can be suppressed, and problems such as stop of the manufacturing process, that is, stop of casting can be suppressed. In the method for producing a copper alloy ingot according to the present embodiment, charcoal, carbon powder, desalco (a type of coke) or the like is used for covering the surface of the molten metal, so that charcoal, carbon powder, desalco (a type of coke), or the like. However, it is possible to prevent problems that occur when the flux is used, for example, the flux is included in the ingot, the casting operation is complicated, and the like.

  Further, in the method for producing a copper alloy ingot according to the present embodiment, the second active element additive is formed including a melting point lowering element. Therefore, even when the second active element additive is continuously added to the molten metal in the tundish where the temperature of the molten metal is lower than the temperature of the molten metal in the melting furnace, the second active element additive is used. It can be dissolved in the molten metal in the tundish, and generation of undissolved residue can be suppressed. Thereby, it can suppress that the undissolved residue of an additive remains in the ingot manufactured, and can suppress generation | occurrence | production of an ingot defect.

  In addition, the first active element additive and the second active element additive in the present embodiment are each formed including an oxidation inhibiting element. Therefore, when the first active element additive and the second active element additive are put into the molten metal, and when the active element is extracted from the molten metal, it is possible to suppress the active element from being oxidized explosively, and the occurrence of intense sparks, etc. Can be suppressed. Thereby, workability in the manufacturing process can be improved, safety can be improved, and loss of the additive element due to generation of a spark or the like can be suppressed. And by including an oxidation inhibitory element, the active element addition yield of the copper alloy ingot can be improved as a result, and the amount of the active element to be contained in the copper alloy ingot to be manufactured is small (that is, added) Even if the amount of the active element to be performed is small), the concentration of the active element along the ingot casting direction can be stabilized.

  In this embodiment, since the copper alloy ingot can be manufactured in the atmosphere, the equipment such as a large vacuum chamber, sealed chamber, etc., compared to the case where the copper alloy ingot is manufactured in vacuum or in an inert gas. By eliminating the need for production, production costs can be reduced and productivity can be improved.

  Hereinafter, embodiments of the present invention will be described in more detail by way of examples.

  The copper alloy ingot according to Example 1 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Mg, and Fe, and the balance being Cu and inevitable impurities. The target composition of the copper alloy ingot cake according to Example 1 was set to Ni: 2.3 mass%, Si: 0.5 mass%, Mg: 0.1 mass%, and Fe: 0.02 mass%. The weight of the copper alloy ingot cake to be manufactured was about 18 t. Specifically, for the purpose of producing the copper alloy ingot according to Example 1, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, and iron raw material were prepared as main raw materials.

  The prepared copper alloy recycled material contains Ni: 2.3% by mass, Si: 0.45% by mass, Mg: 0.1% by mass, Fe: 0.02% by mass, and the remainder from Cu and inevitable impurities. The first copper alloy recycled material comprising: Ni: 2.3 mass%, Si: 0.4 mass%, Zn: 1.7 mass%, P: 0.02 mass%, with the balance being Cu and inevitable It is the 2nd copper alloy recycling material which consists of impurities. The total amount of the first copper alloy recycled material and the second copper alloy recycled material is about 11 t (about 60% of the weight of the copper alloy ingot cake to be manufactured). The prepared electrolytic copper was tough pitch late copper (TPC late copper), and about 7.2 t (about 40% of the weight of the copper alloy ingot cake to be manufactured) was prepared. Further, pure Ni, pure Si, and pure Fe were prepared as nickel raw material, silicon raw material, and iron raw material, respectively. Pure Ni, pure Si, and pure Fe are all about 99.9% pure.

  Also, Mg is selected as the active element, and an Mg—Cu—Ca alloy lump is prepared as the first active element additive, and an Mg—Cu—Ca alloy wire (diameter: φ1 mm) is prepared as the second active element additive. did. The composition of the Mg—Cu—Ca alloy lump and the Mg—Cu—Ca alloy wire was Mg-30 mass% Cu-2 mass% Ca.

  First, the main raw material was melted in the atmosphere, and the molten metal (about 18 t) obtained by melting the main raw material was coated with charcoal. In addition, the concentration of Ni and the like is diluted by the addition of TPC spent copper compared to the case of a copper alloy recycled material alone, but for the diluted amount, pure Ni, pure Si, and pure Fe are added to the molten metal in a predetermined amount. To adjust the concentration. And the Mg-Cu-Ca alloy lump was thrown into the main raw material melt coated with charcoal in the melting furnace in the atmosphere. The amount of the Mg—Cu—Ca alloy ingot introduced was 30% of the amount of Mg contained in the copper alloy ingot cake to be produced. Next, the molten metal in which the Mg—Cu—Ca alloy ingot was dissolved was discharged into a tundish. Subsequently, charcoal was put into the tundish having the molten metal and held for a predetermined time. During the casting, the molten metal was always held in the tundish while keeping the amount of molten metal flowing from the tundish into the mold constant. Therefore, the time during which the molten metal was held in the tundish was about one hour from the start of casting to the end of casting.

  Next, an Mg—Cu—Ca alloy wire (diameter: φ1 mm) was continuously added to the tundish. The amount of added Mg—Cu—Ca alloy wire was 70% of the amount of Mg contained in the copper alloy ingot cake to be produced. And the molten metal which the Mg-Cu-Ca alloy wire melt | dissolved was supplied to the casting_mold | template, and the copper alloy ingot was obtained.

  The change in the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 1 at intervals of 0.5 m in the casting direction.

  Since the copper alloy ingot cake according to Example 2 was manufactured in the same manner as Example 1 except that the diameter of the Mg—Cu—Ca alloy wire used was 2 mm, detailed description thereof was omitted. In addition, the change of Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 2 at intervals of 0.5 m in the casting direction.

  Since the copper alloy ingot cake according to Example 3 was manufactured in the same manner as in Example 1 except that the diameter of the Mg—Cu—Ca alloy wire used was 3 mm, detailed description thereof was omitted. In addition, the change of Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 3 at intervals of 0.5 m in the casting direction.

  The copper alloy ingot according to Example 4 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Zn, P, and Mg and the balance being Cu and inevitable impurities. is there. The target composition of the copper alloy ingot cake according to Example 4 is as follows: Ni: 2.3 mass%, Si: 0.4 mass%, Zn: 2.0 mass%, P: 0.017 mass%, Mg: 0 .1% by mass. Specifically, for the purpose of producing a copper alloy ingot according to Example 4, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, zinc raw material, and phosphorus raw material were prepared as main raw materials. .

  Also, Mg is selected as the active element, and an Mg—Cu—Ca alloy lump as the first active element additive and an Mg—Cu—Ca alloy wire (diameter: φ2 mm) as the second active element additive are prepared. did. The composition of the Mg—Cu—Ca alloy lump and the Mg—Cu—Ca alloy wire was Mg-30 mass% Cu-2 mass% Ca.

  First, the main raw material was dissolved in the atmosphere, and the molten metal obtained by dissolving the main raw material was coated with charcoal. And the Mg-Cu-Ca alloy lump was thrown into the main raw material melt coated with charcoal in the melting furnace in the atmosphere. The amount of the Mg—Cu—Ca alloy ingot introduced was 30% of the amount of Mg contained in the copper alloy ingot cake to be produced. Next, the molten metal in which the Mg—Cu—Ca alloy ingot was dissolved was discharged into a tundish. Subsequently, charcoal was put into the tundish having the molten metal and held for a predetermined time.

  Next, an Mg—Cu—Ca alloy wire (diameter: φ2 mm) was continuously added to the tundish. The amount of added Mg—Cu—Ca alloy wire was 70% of the amount of Mg contained in the copper alloy ingot cake to be produced. And the molten metal which the Mg-Cu-Ca alloy wire melt | dissolved was supplied to the casting_mold | template, and the copper alloy ingot was obtained.

  The change in Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 4 at intervals of 0.5 m in the casting direction.

  In the copper alloy ingot cake according to Example 5, the diameter of the Mg—Cu—Ca alloy wire to be used is set to 3 mm, and the amount of the Mg—Cu—Ca alloy ingot to be charged in the melting furnace is set to the copper alloy cast to be manufactured. Of the amount of Mg contained in the lump cake, the amount of 20% Mg is included, and the amount of added Mg—Cu—Ca alloy wire is the amount of Mg contained in the copper alloy ingot cake to be manufactured. This was manufactured in the same manner as in Example 1 except that the amount contained 80% Mg. Therefore, detailed description is omitted. In addition, the change of Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 5 at intervals of 0.5 m in the casting direction.

  In the copper alloy ingot cake according to Example 6, the diameter of the Mg—Cu—Ca alloy wire to be used is set to 3 mm, and the amount of the Mg—Cu—Ca alloy ingot to be charged in the melting furnace is set to the copper alloy cast to be manufactured. Of the amount of Mg contained in the lump cake, the amount of 40% Mg is included, and the amount of added Mg-Cu-Ca alloy wire is the amount of Mg contained in the copper alloy ingot cake to be manufactured. This was manufactured in the same manner as in Example 1 except that 60% Mg was contained. Therefore, detailed description is omitted. In addition, the change of Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Example 6 at intervals of 0.5 m in the casting direction.

(Comparative Example 1)
The copper alloy ingot according to Comparative Example 1 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Mg, and Fe and the balance being Cu and inevitable impurities. The target composition of the copper alloy ingot cake according to Comparative Example 1 was set to Ni: 2.3 mass%, Si: 0.5 mass%, Mg: 0.1 mass%, and Fe: 0.02 mass%. Specifically, for the purpose of producing a copper alloy ingot according to Comparative Example 1, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, and iron raw material were prepared as main raw materials.

  Moreover, Mg was selected as an active element, and a Cu-50% Mg alloy lump was prepared.

  First, the main raw material was dissolved in the atmosphere, and the molten metal obtained by dissolving the main raw material was coated with charcoal. And the Mg-50% Cu alloy lump was thrown into the molten metal of the main raw material coated with charcoal in the melting furnace in the atmosphere. Next, the molten metal in which the Mg-50% Cu alloy lump was dissolved was poured out into a tundish. Subsequently, the molten metal was supplied from the tundish to the mold to obtain a copper alloy ingot according to Comparative Example 1.

  The change in the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 1 at intervals of 0.5 m in the casting direction.

(Comparative Example 2)
The copper alloy ingot according to Comparative Example 2 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Mg, and Fe and the balance being Cu and inevitable impurities. The target composition of the copper alloy ingot cake according to Comparative Example 1 is the same as that of Comparative Example 1. Specifically, for the purpose of producing a copper alloy ingot according to Comparative Example 1, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, and iron raw material were prepared as main raw materials.

  Further, Mg was selected as the active element, and a Cu-25% Mg clad wire (diameter: φ6 mm) was prepared.

  First, the main raw material was dissolved in the atmosphere, and the molten metal obtained by dissolving the main raw material was coated with charcoal. And the molten metal of the main raw material was poured out into the tundish. Next, Cu-25% Mg clad wire was continuously added to the tundish. Subsequently, the molten metal in which the added clad wire was melted was supplied from the tundish to the mold to obtain a copper alloy ingot according to Comparative Example 2.

  By measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 2 at intervals of 0.5 m in the casting direction, the change in the Mg component along the ingot casting direction was measured.

(Comparative Example 3)
The copper alloy ingot according to Comparative Example 3 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Mg, and Fe, and the balance being Cu and inevitable impurities. The target composition of the copper alloy ingot cake according to Comparative Example 3 is the same as that of Comparative Example 1. Specifically, for the purpose of producing a copper alloy ingot according to Comparative Example 3, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, and iron raw material were prepared as main raw materials.

  Further, Mg was selected as an active element, and a Cu-50% Mg alloy lump and a Cu-25% Mg clad wire (diameter: φ6 mm) were prepared.

  First, the main raw material was dissolved in the atmosphere, and the molten metal obtained by dissolving the main raw material was coated with charcoal. And the Mg-50% Cu alloy lump was thrown into the molten metal of the main raw material coated with charcoal in the melting furnace in the atmosphere. Next, the molten metal in which the Mg-50% Cu alloy lump was dissolved was poured out into a tundish. Then, Cu-25% Mg clad wire was continuously added to the tundish. Subsequently, the molten metal in which the added clad wire was melted was supplied from the tundish to the mold to obtain a copper alloy ingot according to Comparative Example 3.

  The change in the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 3 at 0.5 m intervals in the casting direction.

(Comparative Example 4)
The copper alloy ingot according to Comparative Example 4 is a copper alloy ingot cake (size: 180 mm × 490 mm × 6000 mm) containing Ni, Si, Zn, P, and Mg, and the balance being Cu and inevitable impurities. is there. The target composition of the copper alloy ingot cake according to Comparative Example 4 is as follows: Ni: 2.3 mass%, Si: 0.4 mass%, Zn: 2.0 mass%, P: 0.017 mass%, Mg: 0 0.01 mass%. Specifically, for the purpose of producing a copper alloy ingot according to Comparative Example 4, first, a copper alloy recycled material, electrolytic copper, nickel raw material, silicon raw material, zinc raw material, and phosphorus raw material were prepared as main raw materials. .

  Further, Mg was selected as an active element, and a Cu-50% Mg alloy lump and a Cu-25% Mg clad wire (diameter: φ6 mm) were prepared.

  First, the main raw material was dissolved in the atmosphere, and the molten metal obtained by dissolving the main raw material was coated with charcoal. And the Mg-50% Cu alloy lump was thrown into the molten metal of the main raw material coated with charcoal in the melting furnace in the atmosphere. Next, the molten metal in which the Mg-50% Cu alloy lump was dissolved was poured out into a tundish. Then, Cu-25% Mg clad wire was continuously added to the tundish. Subsequently, the molten metal in which the added clad wire was melted was supplied from the tundish to the mold to obtain a copper alloy ingot according to Comparative Example 4.

  The change in the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 4 at intervals of 0.5 m in the casting direction.

(Comparative Example 5)
In the copper alloy ingot cake according to Comparative Example 5, the diameter of the Mg—Cu—Ca alloy wire to be used is set to 3 mm, and the amount of the Mg—Cu—Ca alloy ingot to be charged in the melting furnace is set to the copper alloy cast to be manufactured. Of the amount of Mg contained in the lump cake, it is assumed that 10% Mg is contained, and the amount of the added Mg—Cu—Ca alloy wire is the amount of Mg contained in the copper alloy ingot cake to be manufactured. This was manufactured in the same manner as in Example 1 except that the amount contained 90% Mg. Therefore, detailed description is omitted. In addition, the change of the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 5 at intervals of 0.5 m in the casting direction.

(Comparative Example 6)
In the copper alloy ingot cake according to Comparative Example 6, the diameter of the Mg—Cu—Ca alloy wire to be used is set to 3 mm, and the amount of the Mg—Cu—Ca alloy ingot to be charged in the melting furnace is set to the copper alloy cast to be manufactured. Of the amount of Mg contained in the lump cake, the amount of 50% Mg is included, and the amount of added Mg—Cu—Ca alloy wire is the amount of Mg contained in the copper alloy ingot cake to be manufactured. This was manufactured in the same manner as in Example 1, except that the amount contained 50% Mg. Therefore, detailed description is omitted. In addition, the change of the Mg component along the ingot casting direction was measured by measuring the Mg component of the obtained copper alloy ingot according to Comparative Example 6 at intervals of 0.5 m in the casting direction.

  As mentioned above, while showing the result of Examples 1-6 and Comparative Examples 1-6 in Table 1, the graph which showed the Mg density | concentration in the casting direction of the copper alloy ingot which concerns on each Example and each comparative example is a figure. 2 to 13 respectively. FIGS. 2-7 is the graph which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Examples 1-6, FIGS. 8-13 is the copper alloy ingot which concerns on Comparative Examples 1-6. It is the graph which showed Mg density | concentration in a casting direction.

  As a result of comparing Examples 1 to 6 with Comparative Examples 1 to 6, the following results were obtained. That is, when an Mg—Cu—Ca alloy is used as the first active element additive and the second active element additive, a Cu-50% Mg alloy and / or a Cu-25% Mg clad wire are used. As compared with the above, it was shown that the Mg addition yield of the copper alloy ingot and the stability of the concentration of the Mg component in the casting direction were improved.

  The diameter of the Mg—Cu—Ca alloy wire used in each example was 3 mm or less. This is because, when an Mg—Cu—Ca alloy wire having a diameter of 4 mm or more is used, there is a limit to improvement in workability when continuously added to the tundish due to the high mechanical strength of the alloy wire. Because. Further, in the examples, when the Mg—Cu—Ca alloy wire having a diameter of 2 mm was used, the Mg addition yield of the copper alloy ingot and the stability of the concentration of the Mg component in the casting direction were the highest. This is because, when the Mg-Cu-Ca alloy wire is supplied to the tundish and the immersion depth of the Mg-Cu-Ca alloy wire in the molten metal after being immersed in the molten metal in the tundish is linear 2 mm, This is probably because the depth from the hot water surface was sufficient.

  In addition, when the amount of Mg added in the melting furnace and the amount of Mg added in the tundish are set to the target amount of Mg contained in the copper alloy ingot to be manufactured, the Mg—Cu—Ca alloy ingot The amount of Mg in the Mg-Cu-Ca alloy wire is reduced to an amount of Mg that is less than b% of the target amount. By including the amount (however, a and b satisfy b = 100−a (where 20 ≦ a ≦ 40)), the Mg addition yield of the copper alloy ingot, the concentration of the Mg component in the casting direction The stability and the quality of the copper alloy ingot were the best. This is because if the amount of Mg added in the melting furnace is too small, even if the Mg—Cu—Ca alloy wire is added at high speed in the tundish, a region with a low Mg concentration is generated in the initial part of casting. This is because the concentration of the Mg component along the casting direction is not uniform. In addition, if the amount of Mg added in the melting furnace is too large, the amount of Mg oxide in the molten metal before casting into the mold increases, resulting in an increase in casting defects in the copper alloy ingot. .

  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.

It is a figure which shows an example of the flow of manufacture of the copper alloy ingot which concerns on this Embodiment. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 1. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 2. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 3. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 4. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 5. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on Example 6. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 1. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 2. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 3. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 4. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 5. FIG. It is the figure which showed Mg density | concentration in the casting direction of the copper alloy ingot which concerns on the comparative example 6. FIG.

Claims (7)

First active element addition step of forming a molten metal containing an active element by adding a first active element additive containing an active element to a melting furnace having a molten metal as a main raw material of a copper alloy ingot in the atmosphere When,
A hot water discharge step of discharging the molten metal containing the active element from the melting furnace to the tundish;
A second active element addition step of adding, in the atmosphere, a second active element additive containing the active element to the molten metal containing the active element discharged from the tundish,
The first active element additive and the second active element additive are respectively
A melting point lowering element that lowers the melting point of the first active element additive and the second active element additive from the melting point of the active element alone;
The manufacturing method of the copper alloy ingot containing the oxidation inhibitory element which suppresses the oxidation of the said active element. The active element is Mg,
The melting point lowering element is Cu;
The method for producing a copper alloy ingot according to claim 1, wherein the oxidation inhibiting element is Ca. The first active element additive and the second active element additive are each Mg alloys,
The said Mg alloy consists of 15 mass% or more and 50 mass% or less of Cu, 1 mass% or more and 5 mass% or less of Ca, and the remainder consists of Mg and an unavoidable impurity. Production method. When the amount of the active element contained in the copper alloy ingot to be manufactured is a target amount,
In the first active element addition step, the first active element additive containing the active element in an amount that is a% of the target amount is added,
In the second active element addition step, the second active element additive containing the active element in an amount that is not more than b% of the target amount is added,
The said a and the said b are the manufacturing methods of the copper alloy ingot of Claim 3 which satisfy | fills b = 100-a (however, 20 <= a <= 40). The first active element additive is an alloy lump,
The method for producing a copper alloy ingot according to claim 3 or 4, wherein the second active element additive is a wire.   6. The method for producing a copper alloy ingot according to claim 5, wherein the wire has a wire diameter of 3.0 mm or less. A first active element additive containing an active element is added to a melting furnace that holds in the atmosphere a main raw material melt in which the main raw material of the copper alloy ingot is melted to form a molten metal containing the active element. 1 active element addition step;
The molten metal containing the active element is discharged from the melting furnace to the tundish, and the second active element additive containing the active element is added to the molten metal containing the active element discharged from the tundish in the atmosphere. A second active element addition step of adding,
The first active element additive and the second active element additive are respectively
A melting point lowering material for lowering the melting points of the first active element additive and the second active element additive than the melting point of the active element alone;
A method for adding an active element comprising an oxidation inhibitor that suppresses oxidation of the active element.

Images