JP2002030366A - DIE FOR Cu HOT EXTRUSION, AND MANUFACTURING METHOD THEREOF - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die for Cu hot extrusion which has small deformation during use, excellent heat check resistance and excellent degradation preventive performance of the heat check resistance caused by the work hardening, and long durable service life. SOLUTION: In manufacturing the die for Cu hot extrusion which is used for hot extrusion of Cu or Cu alloy extrusion stock, an annular-shaped stock 3 having a hollow hole 3a is heated to 700-1,000 deg.C, and rolled in the circumference direction to form the annular die 10 for Cu hot extrusion while holding inner and outer circumferential surfaces of the annular-shaped stock 3 by a pair of forming rolls RA and RB, and a part in the vicinity of the inner surface is annealed by the induction heating, and finished as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die for hot extruding Cu used for hot extruding a Cu or Cu alloy extruded material and a method for producing the same, and more particularly, to a die having less deformation during use. The present invention relates to a Cu hot extrusion die having further improved heat check resistance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a Cu hot extrusion die used for hot extrusion of a Cu or Cu alloy extruded material uses, for example, Inconel 718, a Ni-based super heat-resistant alloy, as a material. In addition to cutting, it was basically manufactured by stretching and heat-treating the material.

[0003]

SUMMARY OF THE INVENTION Such conventional Cu
When used, the hot extrusion dies are, for example, about 8 mm.
Since a billet made of Cu or a Cu alloy heated to a high temperature of 00 ° C. is extruded into a predetermined cross-sectional shape, the temperature reaches about 1000 ° C. during the extrusion, and the surface is repeatedly heated and cooled. As a result, when a certain number of extrusion processes are performed, as shown in FIG. 5A, cracks 42 due to heat check are formed on the inner peripheral side of the hot extrusion die 41. This crack 42 is formed by the hot extrusion die 4.
1 has a problem in that the durability life is reduced.

When a large number of cracks 42 due to such a heat check are generated on the inner peripheral side of the Cu hot extrusion die 41, when the Cu hot extrusion die is used, the Cu 42 Alternatively, as shown in FIG. 5B, the surface of the hollow hole 44 formed by the mandrel in the extruded product 43 is formed smoothly, but the outer periphery of the extruded product 43 is formed as shown in FIG. Since a large number of ridges 45 resulting from the cracks 42 are formed in the portion, there is a problem that the portion cannot be used.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a small deformation during use, has excellent heat check resistance, and has a long durability life. It is intended to provide dies for use.

[0006]

According to the present invention, there is provided a Cu hot extrusion die according to the present invention.
Alternatively, in a Cu hot extrusion die used for hot extrusion of a Cu alloy extruded material, Ni: 5 to 15% by mass, Cr:
15 to 25% by mass, W: 10 to 25% by mass, the balance being an alloy composed of Co and impurities, the hardness in the vicinity of the surface in contact with the extruded material is HRC38 or less, and the hardness in other parts is HRC38 or less. It is characterized by having a hardness distribution exceeding HRC38.

According to a second aspect of the present invention, there is provided a method for producing a Cu hot extrusion die for use in hot extrusion of a Cu or Cu alloy extruded material. In doing this, the annular forming material having a hollow hole is heated to 700 to 1100 ° C., and the inner and outer peripheral surfaces of the annular forming material are rolled in the circumferential direction while being pressed by a pair of forming rolls to form an annular Cu hot material. After being formed into an extrusion die, the vicinity of the inner surface is annealed by high-frequency heating, and a finishing process is performed if necessary.

[0008] In an embodiment of the method for producing a Cu hot extrusion die according to the present invention, the substantially columnar material is upset-forged in the axial direction and the fiber line flows radially. Then, by punching the board-shaped molding material, an annular molding material having a hollow hole can be obtained.

Further, in an embodiment of the method for producing a Cu hot extrusion die according to the present invention, as described in claim 3, the component composition is 5 to 15% by mass of Ni:
r: 15 to 25% by mass, W: 10 to 25% by mass, balance C
o and impurities.

Further, in an embodiment of the method for manufacturing a Cu hot extrusion die according to the present invention, the substantially columnar material is subjected to upsetting forging to obtain a disk-shaped molding material in which fiber lines flow in a radial direction. Forging temperature of 700 to 11
It can be made to be 00 ° C.

Furthermore, in an embodiment of the method for manufacturing a Cu hot extrusion die according to the present invention, a disk-shaped molding material is subjected to rolling to form an annular Cu hot extrusion die in which a fiber line flows in a circumferential direction. The rolling temperature at the time of forming into a die can be set to 700 to 1100 ° C.

[0012]

In the die for hot extruding Cu according to the present invention, the hardness in the vicinity of the surface in contact with the extruded material is HRC38 or less, and the hardness of the other parts has a hardness distribution exceeding HRC38. Therefore, a decrease in heat check resistance due to work hardening is greatly improved.

The substantially columnar material suitably used in the present invention may be one in which no fiber line is formed, and more specifically, a powder material is subjected to hot isostatic pressing (H
A sintered body manufactured by IP) or the like, an ingot obtained by solidifying a molten metal, or the like, and further cut as needed are used. Further, the above-mentioned sintered body or ingot which is lightly processed by a press or the like so as not to form a fiber line for density and shape correction is used.

Then, the annular molding material having a hollow hole obtained by drilling is heated to 700 to 1100 ° C., and the inner peripheral surface and the outer peripheral surface of the annular molding material are pressed in a circumferential direction by a pair of molding rolls. When the diameter is expanded by rolling, the fiber line is oriented in the circumferential direction by the circumferential flow of the material. That is,
It is oriented in a direction perpendicular to the heat check generated and progressing from the inner peripheral side toward the outer peripheral side.

For this reason, when a thermal stress is repeatedly applied during use of the die, the fiber line oriented in the circumferential direction acts as a large resistance to the heat check, and as a result, the Cu hot line according to the present invention works. In an extrusion die, the occurrence and progress of such a heat check are effectively suppressed, and the service life is greatly extended.

In the present invention, if the above-mentioned substantially columnar material has a cylindrical shape, it is necessary that the disk-shaped material formed by upsetting forging in the axial direction has a disk shape. desirable.

In this way, at the stage of the disk-shaped molding material, it can be made to have a shape close to an annular molding material. The need for processing can be eliminated.

After forming into an annular Cu hot extrusion die in this manner, the inner surface is heated and annealed by surface heating means, for example, high frequency heating. This is a Cu hot extrusion die according to the present invention.

More specifically, the hardness distribution is such that the hardness in the vicinity of the surface in contact with the extruded material is HRC38 or less, and the hardness in the other parts exceeds HRC38. Thereby, a decrease in heat check resistance due to work hardening is significantly improved.

[0020]

Next, embodiments of the present invention will be described in detail below.

As shown in FIG. 4, the Cu hot extrusion die 10 has an outer peripheral surface and an inner peripheral surface each having a circular ring shape, an outer diameter D1 of about 150 mmφ, an inner diameter D2 of about 100 mmφ, and a thickness of about 100 mmφ. T has a shape of about 30 mm. Further, both surfaces perpendicular to the axis have a planar shape.

FIGS. 1 to 3 show the manufacturing steps for obtaining the Cu hot extrusion die 10 in order.

First, as shown in FIG. 1 (IA), a substantially columnar material (primary molded product) 1 made of a sintered body is obtained by hot isostatic pressing (HIP) of a powder material. . At this time, there is no fiber line. Alternatively, FIG.
As shown in (IB), the molten metal is solidified to obtain a substantially columnar material (primary molded product) 1 made of an ingot. At this time, there is no fiber line.

Next, by subjecting the substantially columnar material 1 to upsetting forging in the axial direction, as shown in FIG. 1 (II), a disk-shaped molding material (secondarily molded product) 2 is formed. Get. At this time, the fiber line F is in a state of being oriented in the radiation direction.

Then, by performing boring (drilling in the axial direction), as shown in FIG. 1 (III), an annular molding material having an annular shape having a hollow hole 3a in the center portion. (Tertiary molded product) 3 is obtained.

Next, as shown in FIG. 1 (IV), an annular molding material 3 having an annular shape having a hollow hole 3a.
Is heated to 700-1100 ° C. At this time, if the heating temperature is lower than 700 ° C., cracking or chipping may occur during forging, which is not preferable.

Next, as shown in FIG. 1 (V), the inner peripheral surface and the outer peripheral surface of the annular forming material (3) are circumferentially rolled while being narrowly pressed by a pair of forming rolls RA and RB. To form the expanded ring shape
A hot extrusion die (quaternary molded product) 10 is obtained.

In the rolling process in this case, 7
If the temperature is lower than 700 ° C., the deformation resistance during processing tends to increase. If the temperature is higher than 1100 ° C., the hardness of the molded product is H.
It tends to be lower than RC35, and it is preferable that the temperature be 1050 ° C or lower. The processing end temperature is 700 ° C
It is desirable to make the above.

The rolling process is specifically performed as follows. That is, a pair of forming rolls R
A, RB is used to radially narrow the annular forming material 3 from both the inside and the outside, and the annular forming material 3 is rotated in the circumferential direction while rotating the forming rolls RA, RB to allow the material to flow in the circumferential direction. Enlarges the inner and outer diameters.

Next, as shown in FIG. 2 (VI), after being formed into an annular Cu hot extrusion die 10, a high frequency heating coil 5 (for example, 3 turns, 6 MH) is formed on the inner peripheral surface thereof.
z) and heating by high frequency heating (for example, 110
After heating at 0 ° C. or higher, air-cooling) and then annealing. By performing the annealing treatment in this manner, the inner peripheral surface of the Cu hot extrusion die 10 (that is, a portion near the surface that comes into contact with the extruded material) as shown in FIG. The state where the annealing layer 10A is formed is obtained.

FIG. 3 (VII) shows the shape of the Cu hot extrusion die 10 obtained by the rolling process. If necessary, it is possible to perform a strain relief annealing, or As shown in FIG. 3 (VIII), the Cu hot extrusion die 10 thus obtained is obtained.
Is subjected to final mechanical finishing to obtain a Cu hot extrusion die 10 having the final shape and dimensions shown in FIG.

In the die for hot extrusion of Cu and the method for manufacturing the same according to the present invention, Ni: 5 to 15% by mass as a sintered body by hot isostatic pressing (HIP) or as an ingot by solidification of molten metal; Cr: 15 to 25% by mass,
W: It is desirable to have a composition of 10 to 25% by mass, the balance being Co and impurities.

In this case, Ni is a component useful for improving the cold workability and the hot workability. In order to obtain such an effect, Ni is desirably 5% by mass or more.
If the amount is more than 5% by mass, the heat resistance is reduced.
It is good to be mass%.

Further, Cr is a component useful for improving heat resistance, hot oxidation resistance, and heat check resistance. To obtain such an effect, the content is preferably 15% by mass or more. , More than 25% by weight lowers the hot workability, so the content is preferably 15 to 25% by mass.

Further, W is a component useful for increasing hot strength and improving heat check resistance. To obtain such an effect, W is desirably at least 10% by mass. %, The hot workability and the cold workability are reduced, so the content is preferably 10 to 25% by mass.

Since Co has the effect of improving the hot strength and heat check resistance as a matrix, Co is left as the balance.

Further, in the impurities, since C lowers the heat check resistance, the content of C is preferably 0.2% by mass or less, more preferably 0.1% by mass or less.

Further, in the Cu hot extrusion die according to the present invention, it is desirable that the hardness at room temperature in the vicinity of the surface in contact with the extruded material is HRC 38 or less, preferably 35 or less. By this, it is preferable that the decrease in heat check resistance due to heat curing is significantly improved, and the hardness of the other parts at room temperature exceeds HRC38, preferably exceeds 35. It is desirable to have a thickness distribution, and it is better to have a more excellent deformation resistance.

[0039]

EXAMPLES Next, specific examples of the present invention will be described below, but it goes without saying that the present invention is not limited to only such examples.

Example 1 Ni: 10.5% by weight, C
r: 19.6% by weight, W: 18.1% by weight, the balance being Co and impurities, the ingot of which C in the impurities is 0.09% by weight as a material, and is formed into a cylindrical shape by hot forging. The columnar material (d1 in (IA) of FIG. 1)
= 90 mmφ, 1 = 130 mm) 1. The hot forging heating temperature at this time was 1150 ° C.

Next, the substantially columnar material 1 is subjected to an upsetting forging process in the axial direction to form a disk-shaped forming material (d2 = 160 mm in (II) of FIG. 1).
φ, t = 42 mm) 2. The starting temperature of the upsetting forging at this time was 1150 ° C., and the ending temperature was 800.
° C.

Next, a hole is formed in the disk-shaped molding material 2 to form an annular molding material having a hollow hole 3a (in FIG. 1, (III), the inner diameter d3 = 50 mm).
φ) 3 was obtained.

Next, the annular molding material 3 is heated to 950 ° C., and a rolling process is performed on the annular molding material 3 to form a Cu hot extrusion die (((V in FIG. 3)
In II), outer diameter d4 = 172 mmφ, inner diameter d5
= 82 mm, t = 40 mm) 10. The starting temperature of the rolling process at this time was 950 ° C., and the ending temperature was 700 ° C.

Next, after the Cu hot extrusion die 10 was subjected to a strain relief annealing at a temperature of 600 ° C. and a time of 3 hours, the vicinity of the inner peripheral surface was subjected to high frequency as shown in FIG. After heating to a temperature of 1150 ° C., an annealing process of air cooling is performed, and a final mechanical finishing process is performed so that the final shape and dimensions and the hardness in the vicinity of the inner peripheral surface are HR.
A Cu hot extrusion die 10 having C35 and the hardness of the other portions being HRC43 was obtained.

The Cu hot extrusion die 10 thus obtained is subjected to Cu hot extrusion (temperature: 800).
° C, pressure: 5000 Ton) and outer diameter: 100m
m, when a copper tube having an inner diameter of 50 mm was formed, no heat check occurred until the extrusion process was repeated 300 times.

Comparative Example 1 Inconel X750 (Cr:
15.5% by mass, Fe: 7.0% by mass, Al: 0.7% by mass, Ti: 2.5% by mass, the balance of Ni and impurities) was used as a raw material, and the ingot was adjusted to an outer diameter of 160 mmφ. It was stretched.

Then, the drawn material is cut into a predetermined size, and then subjected to a primary solution heat treatment at 1140 ° C. × 2 hr: WQ
845 ° C x 2 as a second solution heat treatment
Heat treatment of 4Hr: WQ, 720 ° C as aging treatment
A heat treatment of × 20Hr: AC was performed, followed by final mechanical finishing to obtain a Cu hot extrusion die (10) having the same shape and dimensions as those shown in FIG.

The Cu hot extrusion die (10) thus obtained was subjected to Cu hot extrusion (temperature: 80).
0 ° C, pressure: 5000 Ton), and outer diameter: 100
When a copper tube having a diameter of 50 mm and an inner diameter of 50 mm was formed, a heat check occurred during the extrusion process with 160 extrusions.

[0049]

According to the die for hot extrusion of Cu according to the present invention, the die for hot extrusion of Cu used for hot extrusion of a Cu or Cu alloy extruded material is characterized in that Ni: 5 to 15% by mass, Cr: 15 to 25% by mass, W: 10 to 25% by mass, the balance consisting of an alloy composed of Co and impurities, the hardness of the vicinity of the surface in contact with the extruded material is HRC38 or less, The hardness of other parts is H
Since it has a hardness distribution exceeding RC38, a great effect that it is possible to provide a Cu hot extrusion die capable of greatly improving the decrease in heat check resistance due to work hardening can be provided. Brought.

By setting the content of C in the impurity to 0.2% by mass or less, it is possible to provide a Cu hot extrusion die having more stable and stable heat check resistance. Significant effects are brought about.

In the method for producing a Cu hot extrusion die according to the present invention, as described in claim 2, a Cu hot extrusion die used for hot extrusion of a Cu or Cu alloy extruded material is produced. At this time, the annular forming material having a hollow hole is heated to 700 to 1100 ° C., and the inner peripheral surface and the outer peripheral surface of the annular forming material are rolled in the circumferential direction while being pressed by a pair of forming rolls to form an annular Cu hot extrusion. After forming into a die, the vicinity of the inner surface is annealed by high-frequency heating and finish processing is performed as necessary, so it has excellent heat check resistance and prevents deterioration of heat check resistance due to work hardening It is possible to produce a large-sized die for hot extrusion.

Then, the substantially columnar material is subjected to upsetting forging in the axial direction to form a disc-shaped molding material in which the fiber lines flow in the radial direction, and then the disc-shaped molding material is hollowed by drilling. The use of the annular molding material has a remarkable effect that a Cu hot extrusion die having excellent heat check resistance can be manufactured.

Further, as described in claim 3, the component composition is as follows: Ni: 5 to 15% by mass, Cr: 15 to 15% by mass.
25% by mass, W: 10 to 25% by mass, made of an alloy composed of the balance Co and impurities, has excellent hot workability, hot oxidation resistance, hot strength, heat check resistance, and heating. A remarkable effect that it is possible to manufacture a long-life Cu hot extrusion die excellent in prevention of deterioration of heat check resistance due to curing.

Further, the disk-shaped molding material is subjected to a rolling process so that the fiber line flows in the circumferential direction.
By making the rolling processing temperature at 700 to 1100 ° C. when forming into a hot extrusion die,
A remarkable effect that it is possible to manufacture a Cu hot extrusion die excellent in hot strength and heat check resistance is provided.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention in which steps (I), (II), and (II) except for an induction annealing step and a final step.
It is explanatory drawing divided and shown to I), (IV), (V).

FIG. 2 is an explanatory view showing a high-frequency annealing step following the step of FIG. 1 as a step (VI).

FIG. 3 shows a final step following the step of FIG.
It is explanatory drawing shown separately in I) and (VIII).

FIG. 4 is a cross-sectional explanatory view ((A) of FIG. 4) and an inclined plane explanatory view ((B) of FIG. 4) showing the shape of a Cu hot extrusion die.

FIG. 5 is a perspective view showing a situation where a heat check has occurred in a Cu hot extrusion die (FIG. 5 (A)), and extrusion molding performed by using a Cu hot extrusion die in which a heat check has occurred; Product explanatory diagram ((B) of FIG. 5)
It is.

[Explanation of symbols]

 Reference Signs List 1 substantially columnar material (primary molded product) 2 disk-shaped molded material (secondary molded product) 3 annular molded material (tertiary molded product) 5 high-frequency heating coil 10 Cu hot extrusion die (fourth molded product) 10A Cu heat Annealing layer of cold extrusion die F Fiber line RA, RB Forming roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22F 1/00 683 C22F 1/00 683 694 694B

Claims (3)

[Claims] 1. A Cu hot extrusion die used for hot extrusion of a Cu or Cu alloy extruded material, wherein Ni: 5
15% by mass, Cr: 15 to 25% by mass, W: 10 to 25
Mass%, the balance consists of an alloy consisting of Co and impurities,
A die for hot extrusion of Cu, wherein the hardness of a portion in the vicinity of a surface in contact with the extruded material is HRC38 or less, and the hardness of other portions has a hardness distribution exceeding HRC38. 2. When manufacturing a Cu hot extrusion die used for hot extrusion of a Cu or Cu alloy extruded material, an annular molded material having a hollow hole is heated to 700 to 1100 ° C. After pressing the peripheral surface and the peripheral surface with a pair of forming rolls to form a circular hot-extrusion die by rolling in the circumferential direction, annealing the vicinity of the inner surface by high-frequency heating and finishing if necessary A method for producing a Cu hot extrusion die. 3. The composition of the composition is as follows: Ni: 5 to 15% by mass;
r: 15 to 25% by mass, W: 10 to 25% by mass, balance C
3. The method for producing a Cu hot extrusion die according to claim 2, comprising an alloy comprising o and impurities.