JPH07197152A - Copper base alloy-made hot extruding/forging material having excellent corrosion resistance and its production - Google Patents

Abstract

PURPOSE:To obtain a copper base alloy-made extruding/forging material having excellent properties of hot extrusion and forging and corrosion resistance. CONSTITUTION:This material has metallic composition contg. 59.0-63.0wt.% copper, 1.0-2.5wt.% lead, 0.4-1.2wt.% tin, 0.3-1.2wt.% nickel and 0.03-0.10wt.% antimony and further contg. either of 0.05-0.4wt.% aluminum or 0.03-0.15wt.% phosphorus or aluminum and phosphorus satisfying the relation of 0.4 Al+ P=0.03-0.15wt.% and the balance zinc with inevitable impurities, and after subjecting this material to the hot extrusion or the hot forging, heat treatment is executed. The heat treatment is executed just after hot-working so that the material is heated up to and held at 500-600 deg.C for 10min-1hr, and then the material is cooled to at least 470 deg.C at <=3 deg.C/min cooling rate.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a copper-based alloy material (ingot,
TECHNICAL FIELD The present invention relates to a hot extrusion / forging material made of a copper-based alloy having excellent corrosion resistance, which is obtained by hot extrusion or hot forging of an extruded material and a drawn material, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Copper-based alloys for forging are generally JI
S C3771 is used, but recently, due to the demand for copper-based alloy products to be used in fields that require corrosion resistance, lead-containing naval brass with tin and lead added to enhance corrosion resistance ( CDA C48200, CDA C4
8500) and the like are also frequently used. However, although these are excellent in hot workability such as hot forgeability, they do not have sufficient corrosion resistance and, for example, hot water, contaminated water,
When contacted with seawater or the like, dezincification corrosion is likely to occur, it cannot be used as a constituent material of equipments handling these fluids, and its use is severely limited.

That is, in order to obtain excellent hot workability (in particular, hot forgeability), it is necessary to have a large amount of β phase at a high temperature such as in the forging temperature region, while excellent corrosion resistance is obtained. In order to obtain the above, it is necessary that the α phase has a single phase structure at room temperature, or that the β phase is finely dispersed even if a small amount of the β phase exists. These conditions cannot be satisfied by the hot forging material.

In particular, in hot forging, there are often portions where the degree of deformation and the degree of working differ greatly, so there is a risk that the corrosion resistance will be significantly reduced partially, and a hot forging material of good quality that is stable as a whole. Can't get This is also a major reason why copper-based alloy products have limited applications.

For example, in the case of manufacturing a valve box made of a corrosion-resistant copper-based alloy containing lead, as shown in FIG. 1, a rod-shaped forging material 1 (the same figure (A)) which is an extruded material is hot forged. As a result, a forged product 2 having hollow portions 2a, 2b, 2c is obtained ((B) of the same figure), but in the forged product 2, there is a portion where the corrosion resistance is significantly reduced. The forged product 2 is finally finished by cutting into a valve box 2'having an inflow port 2'a, an outflow port 2'b, a stem holding portion 2'c, etc. (Fig. (C)).

That is, in order to obtain a forged product 2 having a complicated shape as shown in FIG. 1 (B), a large amount of β phase must be present during hot forging as described above. However, since such a forged product 2 is usually air-cooled or gradually cooled at a high cooling rate after forging, many β
As the phase remains, it is extremely difficult to secure excellent corrosion resistance as described above. And FIG.
A portion that has undergone a considerable amount of deformation and processing, such as the strongly-machined portion Y shown in (B) (hereinafter referred to as the "strongly-machined portion etc.")
In the above, since a considerable amount of β phase is transformed into α phase by cooling after cooling (air cooling or slow cooling at a slightly slower speed), relatively good corrosion resistance can be secured. However, as for the weakly worked portion X shown in FIG. 1B, a portion having a low degree of working or a portion that is hardly deformed with respect to the forging material 1 (hereinafter referred to as "weakly worked portion or the like") is
Since the cooling rate is high as described above, a large amount of β-phase, which is a non-equilibrium state structure, tends to remain, and the directionality of the rod-shaped material 1 also remains, resulting in poor corrosion resistance. Therefore, particularly in a portion such as the X portion, which is finished as the inlet 2'a or the outlet 2'b which is in direct contact with the fluid, the influence of the deterioration of the corrosion resistance is extremely large, and the existence of such a portion. The valve using the valve box 2'which is the final product cannot be used at all in the fields handling hot water, contaminated water, seawater, etc. as described above.

As described above, in a copper-based alloy, improving hot workability and improving corrosion resistance are contradictory requirements, and conventionally, in a field requiring a high degree of corrosion resistance. In reality, it has not been possible to obtain a practical hot extruded material or forged material that can be used.

[0008]

In view of such circumstances, the present invention can satisfy the contradictory requirements described above, and can be put to practical use in a field requiring a high degree of corrosion resistance. It is an object of the present invention to provide a hot-extrusion / forging material made of a base alloy and a method capable of manufacturing the same.

[0009]

The hot extrusion / forging material made of a copper-based alloy of the present invention which solves this problem is made of copper 59.0-6.
3.0% by weight, lead 1.0 to 2.5% by weight, tin 0.4 to
1.2 wt%, nickel 0.3-1.2 wt% and antimony 0.03-0.10 wt%, and aluminum 0.05-0.4 wt% or phosphorus 0.03
To 0.15% by weight or 0.4Al + P = 0.03 to 0.15% by weight of aluminum and phosphorus, and the balance being zinc and inevitable entrained impurities. It is formed by heat treatment after forging.

In the manufacturing method of the present invention, the copper-based alloy material having the above-mentioned metal composition is hot extruded or hot forged into a predetermined shape, and the extruded material or forged material is as follows. It is proposed to heat treat under various conditions.

First, immediately after hot working, at a stage where the forged material or the like is in a high temperature state, the material is heated and held at 500 to 600 ° C. for 10 minutes to 1 hour and then kept at 3 ° C. until the temperature is lowered to at least 470 ° C. It is cooled at a cooling rate of not more than / minute (hereinafter, the heat treatment performed under such conditions is referred to as "first heat treatment"). Such heat treatment can be easily performed by, for example, a continuous heat treatment furnace. Immediately after forging, the forging material is 450 to 650.
Since it maintains a high temperature of ℃, it does not require active heating like a normal annealing furnace, and it is 500-600 ℃ for 10 minutes or longer.
Can be held at. In many cases, it is sufficient to hold for about 10 to 30 minutes. Also, after holding at such temperature,
The cooling rate is usually 3 ° C./minute or less and is gradually cooled to 470 ° C. or less, and more preferably 420 ° C. or less. After such slow slow cooling, air cooling may be performed to room temperature as usual.

Secondly, after the hot working, the forged material and the like which has been brought to room temperature by air cooling is heated and held at 500 to 600 ° C. for 30 minutes to 2 hours and then cooled to at least 470 ° C. at 3 ° C. It is cooled at a cooling rate of not more than / minute (hereinafter, the heat treatment performed under such conditions is referred to as "second heat treatment"). Such heat treatment is carried out in a batch system, and is gradually cooled to about 450 ° C. at the above cooling rate if possible. After such slow slow cooling, cooling is performed by air cooling.

The amount of copper blended is determined mainly in consideration of hot forgeability. That is, in order to ensure excellent hot forgeability, it is necessary that a large amount of β phase be contained in the forging temperature range. That is, when a forged material (extruded material, etc.) is heated to a temperature at which forging is performed (650 to 800 ° C.), the alloy structure of the material is “β phase with high temperature and high ductility”.
It is necessary to transform into a two-phase structure (α + β-phase structure) containing a certain amount or more of. The extent to which the "β-phase having high ductility at high temperature" is contained is determined by the compounding ratio of Cu and other additive elements, and is not generally determined only by the Cu compounding amount, but at least the Cu compounding amount is 63 0.0% by weight
If it exceeds, it is extremely difficult to obtain a β phase exhibiting excellent hot forgeability. In other words, the copper content is 6
By setting the content to 3.0% by weight or less, it is possible to easily transform into the above-described two-phase structure under high temperature conditions, and as a result, it is possible to forge a complicated shape and exhibit excellent hot forgeability. Will be done. Further, if the copper content is less than 59% by weight, the corrosion resistance of the hot-worked product cannot be improved by heat treatment under any condition after hot-working.
For this reason, the copper content is 59.0 to 63.0.
It was set to% by weight.

Tin is added to improve the corrosion resistance, but at the same time, the residual β phase is decomposed into an α phase and a fine γ phase during the slow cooling in the heat treatment process performed after hot working (β Most of the phases are transformed into α phase), β phase is reduced and (finely) divided, it is added in order to obtain high corrosion resistance even after hot forging. To be done. In order to exert such effects, it is necessary to add 0.4% by weight or more. However, if the amount of tin added exceeds 1.2% by weight, the forgeability deteriorates. Moreover, since the amount of γ-phase deposited is large, the corrosion resistance is rather deteriorated, and the γ-phase is hard, so that the machinability is also deteriorated. For this reason, the tin content is 0.4 to 1.2% by weight.
And

Lead is added to improve the machinability, but if the amount added is less than 1.0% by weight, sufficient machinability cannot be obtained. Further, if the addition amount exceeds 2.5% by weight, the forgeability deteriorates. For this reason, the lead content is set to 1.0 to 2.5% by weight.

Nickel has the functions of improving the corrosion resistance, improving the mechanical properties and increasing the α phase structure by the synergistic effect with tin. Also, during hot forging,
It refines the crystal grains to improve the forgeability and also improves the corrosion resistance by the refinement effect. Furthermore, regarding the precipitation of the γ phase during slow cooling in the heat treatment process after forging,
It has the effect of finely dispersing and precipitating the γ phase. In order to exert these effects, it is necessary to add 0.3% by weight or more. However, such an effect is not remarkable even if it is added in an amount exceeding 1.2% by weight, and it is economical. From the aspect, it is a problem. For this reason, the nickel content is 0.3 to 1.2% by weight.

Antimony is an indispensable element for obtaining corrosion resistance, and in particular, in combination with the addition of tin and nickel, 0.03% by weight or more is necessary to exert its effect. However, if added over 0.10% by weight,
It will hinder hot forgeability. For this reason, the content of antimony is 0.03 to 0.10% by weight.
And

Both aluminum and phosphorus are added to improve hot workability. Phosphorus is combined with nickel or iron in unavoidable impurities and added to prevent grain coarsening during heating for hot forging, and particularly enhances hot forgeability at low temperatures. . It also effectively acts on the corrosion resistance. However, if it is less than 0.03% by weight, it is not so effective, and conversely, if it is added in an amount of more than 0.15% by weight, the amount of precipitates increases and the machinability deteriorates. On the other hand, a small amount of aluminum (0.05 wt% or more) dramatically improves the hot workability of the alloy system on the high temperature side and the low temperature side. Further, like nickel, it has the effect of finely precipitating the γ phase during slow cooling of the heat treatment. However, if it is added in an amount exceeding 0.4% by weight, aluminum tends to adversely affect machinability and deteriorate hot workability on the high temperature side.
For this reason, when aluminum is added, the addition amount is 0.05 to 0.4% by weight, and when phosphorus is added instead of aluminum, the addition amount is 0.03 to 0. It was set to 15% by weight.

Aluminum and phosphorus are sufficiently effective when only one of them is added. However, when both are added together, the above-mentioned effects are naturally exhibited. However, according to the experiments and researches by the present inventor, when co-adding,
There is a certain relationship between the two, 0.4Al + P = 0.0
If it is less than 3% by weight, there is little effect, and conversely 0.15% by weight
If it exceeds, machinability becomes a problem. For this reason, when aluminum and phosphorus are added together, 0.4
Al + P was set to 0.03 to 0.15% by weight.

[0020]

[Operation] In producing a hot forged product (or an extrusion molded product) using the copper-based alloy having the above metal composition as a raw material,
Corrosion resistance can be dramatically improved by performing the above-mentioned appropriate heat treatment after hot forging.

For example, in the forged product as shown in FIG. 1 (B), the metal structure of the weakly worked portion has a low degree of deformation and workability as compared with the original bar material which is a forging material, so that it is in a non-equilibrium state. The corrosion resistance is poor because the β phase, which is the structure of, remains in a large amount and the orientation of the rod-shaped material remains, but the forged product that becomes the α single phase in the equilibrium state is heated in the α single phase region of 500 to 600 ° C. When kept, the β phase in the forged product is transformed into the α phase. In the first heat treatment performed on the forged product that is in a high temperature state immediately after forging, if the temperature is kept at the above temperature for 10 minutes or more, such an effect can be sufficiently exhibited. However, the heating and holding time is 60
Beyond the minute, the β phase gradually disappears, but the effect commensurate with the consumed energy cannot be obtained. In addition, since the second heat treatment is performed on the forged product at room temperature,
Long heating time compared to heat treatment (at least 30 minutes)
However, also in this case, if it exceeds 2 hours, an effect commensurate with the consumed energy cannot be obtained. In the state diagram, for example, a copper-based alloy material with a copper concentration of 62.5% is
When hot forged at 0 ° C, β phase (750
℃) is 44%, which is 61% on the equilibrium diagram.
It becomes an α single phase at 0 ° C or lower.

However, as described above, the forged product is
When heated and held at 600 ° C. for a certain period of time, the β phase in the forged product undergoes phase transformation into the α phase, but the transformation amount is only about 70%, and the β phase still remains. Moreover, this β phase remains in a continuous form along the grain boundary of the α phase. Therefore, although heating after forging has an effect of improving the corrosion resistance to some extent, it is extremely insufficient from the viewpoint of drastically improving the corrosion resistance.

The slow gradual cooling after heating and holding, together with the inclusion of 0.4% by weight or more of tin, completely eliminates this problem, and the precipitation of the γ phase is extremely effective. By utilizing it, the corrosion resistance is dramatically improved.

That is, even in the case of a general brass forged product, after being heated and held at 500 to 600 ° C., the temperature is 3 ° C. /
If it is slowly cooled slowly for less than a minute, a phase transformation from β phase to α phase occurs, but for the forged product made of brass containing 0.4 wt% or more of tin (copper concentration is around 61%), slow cooling As a result, in the temperature decreasing region from 520 ° C. to 400 ° C., the γ phase having a higher tin and zinc concentration than the α phase and the β phase is precipitated.
Such a phenomenon is particularly remarkable in the temperature decreasing region from 500 ° C to 450 ° C. Such precipitation of the γ phase results in β
This is due to the eutectoid reaction that decomposes the phase into the α phase (mostly) and the γ phase, which is much faster than the simple phase transformation in which the β phase transforms into the α phase. According to the research conducted by the present inventor, it was found that the γ phase is precipitated in a non-equilibrium state even when the tin content is 0.4 to 0.6% by weight.

Therefore, in the brass material having the above-mentioned metal composition, and particularly containing 0.4% by weight or more of tin, as described above, the β phase is changed to the α phase and the fine γ phase by slow cooling. However, a part of this γ phase is further transformed into the α phase,
Significantly reduces β-phase, which adversely affects corrosion resistance. Further, even if the β phase is not completely replaced with the α phase and the γ phase and remains, the β phase continuously existing in the crystal grain boundary of the α phase is a fine γ phase. The precipitation will cause complete separation and fragmentation, and the adverse effect of the residual β phase on the corrosion resistance will be extremely small. According to the results of experiments and research conducted by the inventor, the γ phase is Cu-containing a high tin concentration.
Since it is a Zn-Sn-based intermetallic compound, even if the γ phase is deposited, if it is fine (in other words, if the γ phase is not continuously distributed), the corrosion resistance is not affected at all. Does not reach.

Therefore, after the forging, the first heat treatment or the second heat treatment is performed.
By performing the heat treatment, the corrosion resistance can be dramatically improved. In particular, for a forged product such as the above-mentioned part X where there is a weakly worked part that comes into direct contact with a fluid, the corrosion resistance as a whole is improved and a fluid such as hot water, contaminated water, seawater, etc. is handled. It can be suitably used as a component of a device.

[0027]

EXAMPLES Examples of the present invention will be described below.

As an example, copper-based alloy No. 1 having the composition shown in Table 1 was used. 1, No. 26m diameter by hot extruding 2
750 ° C after cutting each bar to the specified size
After heating, a hollow forged product having a shape as shown in FIG. 1 (B) was obtained. In addition, iron in Table 1 is an unavoidable accompanying impurity.

As a comparative example, copper-based alloy No. 1 having the composition shown in Table 1 was used. 3 to No. 5 was hot extruded and hot forged under the same conditions as above to obtain a hollow forged product having the same shape. In addition, No. 5 is the brass for forging of JIS C3771 mentioned at the beginning.

[0030]

[Table 1]

Each hollow forged product No. 1-No. 5
(Forged product No. x is made of copper-based alloy No. x) was heat-treated under the conditions A to H described below.

Condition A: Each forged product was air-cooled to room temperature after forging in the same manner as the post-forging treatment in a general forging process. Condition B: Each forged product was held at 550 ° C. for 20 minutes immediately after forging, then furnace-cooled to 430 ° C. at an average cooling rate of 2 ° C./minute, and then air-cooled. Condition C: Each forged product was held at 550 ° C. for 20 minutes immediately after forging, cooled to 430 ° C. at an average cooling rate of 4 ° C./minute, and then air-cooled. Condition D: Each forged product that was air-cooled after forging was heated at 550 ° C. for 1 hour and then air-cooled. Condition E: Each forged product that was air-cooled after forging was heated at 550 ° C. for 1 hour, then furnace-cooled to 490 ° C. at a cooling rate of 1 ° C./min, and then air-cooled. Condition F: Each forged product that was air-cooled after forging was heated at 550 ° C. for 1 hour, then furnace-cooled to 450 ° C. at a cooling rate of 1 ° C./min, and then air-cooled. Condition G: Each forged product air-cooled after forging was heated at 550 ° C. for 1 hour, then furnace-cooled to 400 ° C. at a cooling rate of 1 ° C./min, and then air-cooled. Condition H: Each forged product that was air-cooled after forging was annealed at 470 ° C. for 1 hour and then air-cooled.

The heat treatment under the condition B is the first heat treatment, and the heat treatment under the conditions F and G is the second heat treatment. Further, the heat treatment under the conditions D to H was performed in a batch system.

Each forged product No. which was heat-treated under these conditions A to H was used. 1-No. From FIG. 5, the weakly worked portion X and the strongly worked portion Y shown in FIG. 1 (B) were cut out, and the cut zinc pieces were subjected to a dezincification corrosion test by the method defined in “ISO 6509”. That is, each cut piece was embedded in a phenol resin material, the surface of the cut piece was polished to No. 1200 with emery paper, and then ultrasonically washed in pure water and dried.
The corrosion test sample thus obtained was treated with a 1.0% aqueous solution of cupric chloride dihydrate (CuCl ₂ .2H ₂ O) (1
2.7 g / l) and 24 at a temperature of 75 ° C.
After holding for a period of time, it was taken out from the aqueous solution and the maximum value of its dezincification corrosion depth was measured.

The results are as shown in Table 2 for the weakly processed portion X (the exposed surface is perpendicular to the extrusion direction) and as shown in Table 3 for the strongly processed portion Y.

As can be seen from Table 2, in the weakly worked portion X, the copper-based alloy forged product containing a large amount of tin is furnace-cooled at a rate of 3 ° C./min or less to 470 ° C. or less, and thereby the corrosion resistance is remarkably improved. To be done. However, tin containing less than 0.4 wt% N
o. In No. 4, even in the state where heat treatment is not performed (even if it is a forged product) 1-No. Corrosion resistance is slightly poorer than that of No. 3, and it is possible to reduce the maximum dezincing depth by about 20 to 30% under any conditions by applying heat treatment, but the effect of slow cooling is only slightly recognized. I can't. JIS C
No. 3771. Regarding No. 5, although the corrosion depth is reduced by 10 to 20%, the effect of gradual cooling is small.
Further, the heat treatment (annealing) under the condition H is performed at a substantially central temperature in the temperature range in which the β phase decomposes into the α phase and the γ phase. However, if the heat treatment is simply performed at the phase decomposition temperature as described above,
It is understood that the maximum corrosion depth is only reduced by about 30%, and the effect of improving the corrosion resistance is much smaller than that in the case of the heat treatment of the conditions B, F and G in the present invention.

[0037]

[Table 2]

Further, as can be understood from Table 3, No. 1-No. No. 3 has a shallow corrosion depth even if it is originally forged (when it is not heat treated), but the corrosion resistance is remarkably improved by slow cooling. However, in No. 3 having a low tin content. 4 and JIS C3771 No. 5
Regarding the above, although there is some effect of slow cooling from the viewpoint of improving the corrosion resistance, it is extremely small.

[0039]

[Table 3]

Each extruded material (round bar with a diameter of 26 mm) obtained as described above was cut to obtain a required number of round bar-shaped test pieces with a diameter of 15 mm and a height of 25 mm. And each test piece No. 1-No. 5 (test piece No. x is made of copper-based alloy No. x), and 660
℃, 700 ℃, 740 ℃, 780 ℃, 820 ℃, and hold for 30 minutes, then compressed at a compression rate of 70% in the axial direction (the height of the test piece is compressed from 25 mm to 7.5 mm)
Then, the surface morphology after compression was visually determined. The result is
The results are shown in Table 4. The judgment was visually conducted from the state of cracks on the side surface of the test piece, and those in which no cracks were generated were evaluated as ◯, those in which small cracks were generated as Δ, and those in which large cracks were generated as x.

[0041]

[Table 4]

As can be seen from Table 4, No. 5 (J
IS C3771) does not cause cracks except when heated to 820 ° C. and has a small amount of aluminum.
No. 1 had some cracks when heated to 660 ° C., but no cracks at 700 to 820 ° C. In addition, No. 5 containing a small amount of phosphorus. 2, No. 4 is
No. containing no phosphorus or aluminum It is understood that the forgeability is superior to that of No. 3.

By the way, also in the forged product, when the shape becomes more complicated, at a moment, at the time of forging, a temperature drop locally occurs at a portion in contact with the forging die (a portion having a high degree of deformation). Therefore, even when the temperature is lower than the heating temperature at the time of forging (for example, about 100 ° C. lower), better forgeability (hot workability) is required. However, the one of the present invention is excellent in hot workability due to the metal composition,
Good hot working can be performed even when such a local temperature drop occurs.

[0044]

As can be easily understood from the above description, the copper-based alloy extruded and forged material of the present invention has a metal composition necessary for corrosion resistance, and particularly contains 0.4% by weight or more of tin. By including it, the β phase can be eliminated or finely separated by heat treatment after hot working, and it is extremely excellent in all parts of the processed product even when hot working under any conditions. It has corrosion resistance. Further, the metal composition is naturally excellent in machinability and strength. Therefore, equipment that handles hot water, contaminated water, seawater, etc. that could not be used with conventional brass-based alloy materials (or had a major problem in terms of corrosion resistance when used) (hot water taps, valves , Mechanical parts, parts for ships, etc.) and its applications are extremely wide.

Further, according to the manufacturing method of the present invention, a copper-based alloy extruded / forged material excellent in both corrosion resistance and hot workability can be manufactured inexpensively and efficiently. In particular,
Practically, there is a large difference in the forging temperature, and there is a large difference in the workability of each part in the forged product, and even under conditions where only a forged product with a dissimilar metal structure can be obtained, a high quality product with an extremely stable metal structure is manufactured be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of a valve box.

[Explanation of symbols]

1 ... Forged material, 2 ... Forged product (extrusion / forging material made of copper-based alloy).

Claims (3)

[Claims] 1. Copper 59.0 to 63.0% by weight and lead 1.0
~ 2.5 wt%, tin 0.4-1.2 wt%, nickel 0.3-1.2 wt% and antimony 0.03-0.1
It contains 0% by weight of aluminum and 0.05-
0.4% by weight or 0.03 to 0.15% by weight of phosphorus or 0.4Al + P = 0.0 of aluminum and phosphorus
A hot work made of a copper-based alloy having a corrosion resistance of 3 to 0.15% by weight and the balance being zinc and unavoidable impurities, and being subjected to heat treatment after hot extrusion or hot forging. Extruded / forged material. 2. Copper 59.0-63.0% by weight and lead 1.0
~ 2.5 wt%, tin 0.4-1.2 wt%, nickel 0.3-1.2 wt% and antimony 0.03-0.1
It contains 0% by weight of aluminum and 0.05-
0.4% by weight or 0.03 to 0.15% by weight of phosphorus or 0.4Al + P = 0.0 of aluminum and phosphorus
A copper-based alloy material containing 3 to 0.15% by weight and the balance being zinc and inevitable accompanying impurities is hot extruded or hot forged into a predetermined shape, and the extruded material or forged material is Immediately after hot working, heat treatment was performed at 500 to 600 ° C. for 10 minutes to 1 hour, and then cooled at a cooling rate of 3 ° C./minute or less until the temperature was lowered to at least 470 ° C. , A method for manufacturing hot-extruded and forged materials made of copper-based alloy with excellent corrosion resistance. 3. 59.0 to 63.0% by weight of copper and 1.0 of lead
~ 2.5 wt%, tin 0.4-1.2 wt%, nickel 0.3-1.2 wt% and antimony 0.03-0.1
It contains 0% by weight of aluminum and 0.05-
0.4% by weight or 0.03 to 0.15% by weight of phosphorus or 0.4Al + P = 0.0 of aluminum and phosphorus
A copper-based alloy material containing 3 to 0.15% by weight and the balance being zinc and inevitable accompanying impurities is hot extruded or hot forged into a predetermined shape, and the extruded material or forged material is Once air-cooled, it is heated to 500-600 ℃ for 30 minutes-2
Hot-extrusion made of copper-based alloy excellent in corrosion resistance, which is heat-treated under the condition that the material is kept heated for a time and cooled at a cooling rate of 3 ° C./minute or less until the temperature is lowered to at least 470 ° C. Manufacturing method of forged material.