KR101852053B1

KR101852053B1 - Copper-based alloy

Info

Publication number: KR101852053B1
Application number: KR1020157035157A
Authority: KR
Inventors: 요시하루 코사카; 신야 우에노
Original assignee: 산에츠긴조쿠가부시키가이샤
Priority date: 2013-06-05
Filing date: 2014-06-03
Publication date: 2018-04-25
Also published as: JP5953432B2; WO2014196518A1; CN105264101B; KR20160015252A; CN105264101A; JPWO2014196518A1; DE112014002690T5; US20150368759A1

Abstract

The present invention relates to a steel sheet comprising, by mass%, 63.5 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15% of Fe, 0.1 to 2.0% of Pb or 0.5 to 1.5% of Bi, 0.01 to 0.2% P: 0.04 to 0.15% when the content of Cu is less than 63.5 to 65.0%, and P: 0.15% or less when the content of Cu is 65.0 to 69.0% And the remainder is made of Zn and impurities. The copper-based alloy is excellent in resistance to dezincification without being subjected to heat treatment.

Description

Copper-based alloy {COPPER-BASED ALLOY}

The present invention relates to a copper-based alloy, and more particularly to a copper alloy which is suitable for parts contacting with water such as faucets and valves, resistance against dezincification, erosion corrosion, Resistant to stress corrosion cracking, and the like.

Among copper-based alloys, bronze alloys are excellent in resistance to dezincification, resistance to erosion corrosion and stress corrosion cracking while being cast, but they are expensive compared with brass alloys, The demand for alloys is increasing recently.

Patent Document 1 discloses an alloy excellent in corrosion resistance, which contains at least 0.05 to 0.2% by weight of Sn and at least one or two kinds of Sb, As or P in a copper alloy composed of two phases of an? Phase and? (JBMA test) and a solidification temperature range of 17 占 폚 or lower.

However, the alloys disclosed in Patent Document 1 are capable of maintaining tolerance to deasphalting corrosion by performing heat treatment.

Further, in the case of a component used in a region where a flow velocity of a faucet or the like is accelerated, resistance to erosion and corrosion is insufficient, and the field that can be used is limited.

Patent Document 2 discloses a steel sheet having a composition of 61.2? Cu <64.0%, Sn: 0.8 to 2.0%, Sb: 0.04 to 0.15%, Al: 0.4 to 0.7%, Pb: 0.5 to 3.0% (Remaining portion) is made of Zn and unavoidable impurities. In addition, by containing 0.2 to 1.0% of Ni at a mass ratio, resistance to dezincification is improved without heat treatment, and furthermore, by making the macro crystal grains finer, An alloy having a maximum dezinc corrosion depth of 200 mu m or less is disclosed.

However, the alloy disclosed in Patent Document 2 achieves an ISO maximum zinc depletion depth of 200 탆 or less due to the effect of refinement by B and Fe, but atmospheric dissolution without using a molten metal coating material is common in sand mold casting , The amount of B to be added is so large that an intermetallic compound is formed in B and Fe, which may deteriorate the abrasive property.

In particular, in the case of a metal-plated metal plate subjected to polishing, the generation of intermetallic compounds of B and Fe is fatal.

The ISO maximum zinc depletion depth of 200 占 퐉 is a standard value as a material having resistance to dezincification (anti-corrosive lead material), which means a lower limit value of the standard and is preferably 100 占 퐉 or less Do.

Further, in the copper-based alloys disclosed in the above publications, as described in all of the examples, Ni is a substantially necessary element.

However, since Ni is an environmental load substance, it is expected to be added to the water quality standard in the near future, so it is not preferable to add Ni to the casting material used for the water supply or valve.

Japanese Patent Publication No. 3461081 Japanese Patent Application Laid-Open No. 2009-263787

An object of the present invention is to provide a copper-based alloy made of a brass alloy excellent in resistance to dezincification without heat treatment.

The copper-based alloy according to the present invention is excellent in resistance to de-zinc corrosion without heat treatment, has excellent resistance to erosion corrosion and resistant to stress corrosion cracking, and is superior in corrosion resistance to corrosion caused by corrosion of Pb-based copper- Based alloy of the Pb-based alloy has a composition of 63.5 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15 to 0.15% of Fe, 0.1 to 2.0% of Pb, P: 0.04 to 0.15% when the content of Cu is less than 63.5 to 65.0% and P: 0.15% or less when the content of Cu is 65.0 to 69.0%, the content of Al is 0.01 to 0.2% and the content of Sb is 0.06 to 0.15% , And the remainder is composed of Zn and impurities.

A feature of the present invention resides in that, in a copper-based alloy (brass), it is possible to maintain resistance to dezincification of not more than 100 占 퐉 in maximum ISO dezincification depth without heat treatment without addition of B or Ni which is a harmful element in the metal fitting .

Regarding the resistance against stress corrosion cracking, the casting material is characterized in that it is difficult for cracks to advance because there is no crystal directionality.

The copper-based alloy suitable for casting according to the present invention contains, in terms of mass%, 63.5 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15% of Fe, 0.1 to 2.0% P: 0.04 to 0.15% when the content of Cu is less than 63.5 to 65.0%, P: 0.15% or less when the content of Cu is 65.0 to 69.0%, and S: 0.06 to 0.15% At least one element selected from the group consisting of Te: 0.01 to 0.45% and Se: 0.02 to 0.45% and / or at least one element selected from the group consisting of 0.001 to 0.2% of Mg and 0.005 to 0.2% of Zr , And the remainder is composed of Zn and impurities.

Next, as the Bi-based copper-based alloy according to the present invention, the alloy containing 63.5 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15% of Fe, 0.5 to 1.5% of Bi, P: 0.04 to 0.15% when the content of Cu is less than 63.5 to 65.0%, P: 0.15% or less when the content of Cu is 65.0 to 69.0%, and S: 0.06 to 0.15% , And the remainder is composed of Zn and impurities.

The steel sheet according to any one of claims 1 to 3, wherein the steel has a composition of 63.5 to 69.0% Cu, 1.2 to 2.0% Sn, 0.15% Fe, 0.5 to 1.5% Bi, 0.01 to 0.2% Al and 0.06 to 0.15% , P component is an optional component in the range of P: 0.04 to 0.15% when Cu is less than 63.5 to 65.0% and P: 0.15% when Cu is 65.0 to 69.0%, Te: 0.01 to 0.45%, Se : 0.02 to 0.45%, and / or at least one element selected from the group consisting of 0.001 to 0.2% of Mg and 0.005 to 0.2% of Zr, and the balance of Zn and impurities do.

The brass alloy according to the present invention can be used as a substitute for a bronze alloy.

As an alloy for use in contact with water, it is possible to achieve an ISO maximum dezinc corrosion depth of 100 μm or less without adding any harmful elements such as Ni or B and without heat treatment.

Also, it is resistant to erosion corrosion and resistance to stress corrosion cracking.

Fig. 1 shows a composition table and an evaluation result of a copper-based alloy used for evaluation.
Fig. 2 shows a composition table and an evaluation result of a copper-based alloy used for evaluation.
Fig. 3 shows a sample collection diagram.
Fig. 4 shows a test method of erosion corrosion.

Hereinafter, the components of the copper-based alloy in the present invention will be described.

The Cu component is preferably in the range of 63.5 to 69.0%.

If the Cu content is less than 63.5%, the? Phase increases and the corrosion resistance is lowered.

Increasing the Cu component improves the corrosion resistance such as resistance to de-zinc corrosion, but it is expensive and the strength is lowered, so that the range of 63.5 to 69.0% is preferable.

Pb is an additive element for improving machinability. In the present invention, 0.1% or more is contained if necessary. When it exceeds 2.0%, the strength is lowered, so that it is 2.0% or less.

Further, from the viewpoint of improvement in machinability, Bi may be contained in an amount of 0.5 to 1.5% instead of Pb.

Sn is an element necessary for securing resistance to dezincification and resistance to erosion and corrosion. To obtain resistance to erosion corrosion at the bronze level, the content of Sn is required to be 1.2% or more, more preferably 1.5% or more.

If the Sn content exceeds 2.0%, even if the resistance to dezincification is good, the elongation value of the mechanical properties deteriorates when the Sn is used while being cast. From the viewpoint of securing the elongation value, it is more preferable that it is 1.8% or less. Accordingly, the range of Sn is 1.2 to 2.0%, and more preferably 1.5 to 1.8%.

Fe is apt to form a compound with P and reduces the effect of P, so that Fe is preferably 0.15% or less.

Al is contained to prevent oxidation of P.

In order to prevent oxidation of P, it is necessary to contain at least 0.01% or more.

If the Al content is 0.2% or more, the resistance to dezincification in the present component range is reduced, so that the range of Al is set to 0.01 to 0.2%.

From the viewpoint of resistance to dezincification, a more preferable range is 0.01 to 0.1%.

Al also has an effect on improving the flowability of the molten metal. However, in order to maintain the molten metal flowability equivalent to that of bronze, this level of Al content is sufficient.

Sb is contained to improve the resistance to dezincification.

In order to ensure the ISO maximum dezinc depth of 100 탆 or less without heat treatment, 0.3% or more of the γ phase needs to be contained.

For this purpose, it is necessary to contain at least 0.06% or more.

Further, when it exceeds 0.15%, it becomes brittle, so that the content range of Sb is set to 0.06 to 0.15%.

When both the resistance to dezincification and the mechanical properties are considered, the more preferable range is 0.08 to 0.13%.

P is contained together with Sb to improve the resistance to dezincification. However, when Cu is less than 65%, it is an essential element, but when Cu is 65% or more, it is an arbitrary element.

In order to ensure an ISO maximum dezinc depth of 100 mu m without heat treatment, when Cu is less than 65%, it is necessary to contain at least 0.04% or more.

More preferred is 0.06% or more.

On the other hand, if the content exceeds 0.15%, segregation tends to occur when casting is carried out, so that it is in the range of 0.04 to 0.15%.

For reference, when Cu is 65% or more, resistance to dezincification is excellent even if P is not contained, and may be arbitrarily added in the range of 0.15% or less.

The Te component improves the machinability. The Te content is effective at not less than 0.01%, and when it is added in view of obtaining an effect corresponding to the addition amount and economical efficiency, the upper limit is set to 0.45%.

The Se component improves the cutting performance, but suppresses the Se component to the maximum because the material cost is high.

In addition, since the hot workability (hot workability) deteriorates, it is preferably 0.45% or less.

When the Se component is added, it is preferably in the range of 0.02 to 0.45%.

The Mg component has an effect of improving strength by grain refinement, improving flowability of molten metal, and deoxidizing and desulfurizing effects.

When 0.001% or more of Mg is contained in the molten metal, the S component in the molten metal is removed in the form of MgS.

If the Mg content exceeds 0.2%, the viscosity of the molten metal is increased by oxidation, which may cause casting defects such as mixing of oxides.

Therefore, when the Mg component is added, the effect is obtained in the range of 0.001 to 0.2%.

The Zr component has a grain refining action.

An effect of more than 0.005% appears.

Further, Zr has a strong affinity with oxygen, and when it exceeds 0.2%, it is oxidized to increase the viscosity of the molten metal, and there is a fear of causing casting defects such as mixing of oxides.

Therefore, when Zr is added, it is in the range of 0.005 to 0.2%.

Example 1

As a test material, a melt having various alloy compositions as shown in the tables of FIG. 1 and FIG. 2 was prepared, and a test piece of JIS H5120 A disclosed in FIG. 3 (sand mold) ), Cooled (solidified), and then the frame was disassembled to obtain a sample.

For reference, there are A and B casting molds to be disclosed, and this time, it was confirmed as A disclosure material.

The remainder (Zn) in the table also contains unavoidable impurities.

&Lt; Evaluation test >

(1) Immunity test for dezincification

The test piece was immersed in a solution of 12.7 g / l of CuCl ₂ .2H ₂ O at 75 ± 3 ° C for 24 hours in accordance with ISO, Dezinc corrosion depth was measured and evaluated according to the following criteria.

When the depth of dezincification is less than 100 탆, it is acceptable, and when the depth of dezincification exceeds 100 탆, it is rejected.

For reference, in this evaluation test, it was evaluated more strictly than the ISO standard of 200 탆 or less.

(2) Tensile test

A tensile test was conducted on a JIS Z 2201 No. 4 test specimen, which was taken from JIS H5120 A (run type) and machined and processed by Amsler's universal testing machine.

A sample having a strength exceeding 200 MPa was rated as & cir &

A case where the elongation percentage was more than 15% was rated as?, A case where it exceeded 12% was rated as?, And a case where it was less than 12% was evaluated as X.

(3) Erosion corrosion evaluation test

The test liquid is ejected onto the surface of the test piece using the test apparatus as shown in Fig. 4, and the erosion corrosion is forcibly caused by the shear force generated by the disturbance of the test liquid flowing through the clearance between the test piece and the nozzle, Depth and corrosion pattern were evaluated.

Test solution: CuCl ₂ .2H ₂ O (12.7 g / 1000 ml)

· Test temperature: 40 ℃

· Flow rate: 0.2 l / min

· Maximum flow rate: 0.62m / sec

· Exam time: 7 hours

The evaluation results are shown in the tables of Fig. 1 and Fig.

The strength shows the result of the evaluation of the tensile strength by the above-mentioned tensile test, and the elongation was also evaluated by the above criteria.

The dezinc depth represents a specific measurement, and the unit is μm.

Inventive alloys Examples 1 to 20 and 27 to 47 show Pb-based brass alloys, and Examples 21 to 24 and 48 to 69 show Bi-based brass alloys.

Examples 25 and 26 are Pb-based alloys to which P is not added.

All of these components were included in a predetermined range, and the resistance to dezincification was excellent without heat treatment.

In Example 47, since the quality target is achieved even if the Cu component is 69.34%, it is estimated that there is no problem even if the Cu component exceeds 69.0%.

In Example 39, since the quality target is achieved even if the Pb component is 2.10%, there is no problem even if the Pb component exceeds 2.0%.

On the contrary, in Comparative Examples 101 and 102, since the Cu component was less than 63.5% and Al was slightly larger, resistance to dezincification was inferior.

Also, the elongation did not achieve the target.

In particular, in Comparative Example 113, P and Sb were not included and the resistance to dezincification was inferior.

In Comparative Examples 103 to 107, since the Sn content exceeded 2.0%, even if the resistance to dezincification was good, the elongation did not achieve the target.

In Comparative Examples 108 and 109, the resistance to dezincification was inferior because the Cu component was less than 63.5%, and 110 was higher than Al by 0.2%.

In Comparative Example 111, the elongation did not achieve the target because Sn exceeded 2%.

Further, in Comparative Example 112, Cu was less than 65% and P was not contained, so that resistance to dezincification was inferior.

Next, an erosion corrosion evaluation test was carried out.

The samples were also evaluated for comparison for alloys of Inventive Alloy 3 and Comparative Example 113 and bronze materials (CAC406C: Sn: 3.67%, Zn: 5.76%, Pb: 4.20%, balance Cu).

As a result, with respect to the maximum corrosion wear depth, Inventive Alloy 3 was 66 μm, Comparative Example 113 was 700 μm, and Bronze Material was 63 μm.

In the corrosion type, Inventive Alloy 3 was in a layer form, while Comparative Example 113 was in a ring form.

For reference, the bronze material was layered.

From this, it can be seen that the brass alloy according to the present invention is sufficiently usable as a substitute material for the bronze alloy.

(Industrial availability)

The copper-based alloy according to the present invention can be widely applied to products used in a place where water is used, in which resistance to high dezincification and resistance to erosion corrosion are required.

Further, it is useful for lowering the cost of the conventional brass alloy in that heat treatment after casting is not required.

Claims

The steel sheet according to any one of claims 1 to 3, wherein the steel sheet contains, in mass%, 63.5 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15% of Fe, 0.1 to 2.0% of Pb, 0.01 to 0.2% of Al and 0.06 to 0.15%
The P component is an optional additive component in the range of P: 0.04 to 0.15% when Cu is less than 63.5 to 65.0% and P: 0.15% when Cu is 65.0 to 69.0%
Wherein the remainder is composed of Zn and impurities, does not contain Zr, and has a depth of dezinc not more than 100 占 퐉 without heat treatment.

Wherein the content of Cu is 63.5 to 69.0%, Sn is 1.2 to 2.0%, Fe is 0.15%, Pb is 0.1 to 2.0%, Al is 0.01 to 0.2% and Sb is 0.06 to 0.15%
The P component is an optional additive component in the range of P: 0.04 to 0.15% when Cu is less than 63.5 to 65.0% and P: 0.15% when Cu is 65.0 to 69.0%
0.001 to 0.2% of Mg, at least one element selected from the group consisting of Te: 0.01 to 0.45% and Se: 0.02 to 0.45%, the remainder being composed of Zn and impurities and not containing Zr, Wherein the copper-based alloy has a depth of dezincification of 100 mu m or less.

The steel sheet according to any one of claims 1 to 5, wherein the steel sheet contains, in terms of mass%, 66.75 to 69.0% of Cu, 1.2 to 2.0% of Sn, 0.15% of Fe, 0.5 to 1.5% of Bi, 0.01 to 0.2% of Al and 0.06 to 0.15%
P: an additive component in the range of? 0.15%
Wherein the remainder is made of Zn and impurities, does not contain Zr, and has a depth of dezincification of not more than 100 mu m without heat treatment.

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