JPH05171320A - High strength Cu alloy key material with excellent corrosion resistance - Google Patents

Abstract

(57) [Abstract] [Purpose] To develop a key material made of Cu alloy that has high strength and excellent corrosion resistance. [Structure] A key material, by weight%, Zn: 15 to 35%, Ni: 7 to 14%, Mn: 0.1 to less than 2%, Fe: 0.01 to 0.5
%, P: 0.001 to 0.1%, and the balance being a Cu alloy having a composition of Cu and inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Cu alloy key material having excellent corrosion resistance and high strength.

[0002]

2. Description of the Related Art Conventionally, it is well known that brass having a typical composition of Cu-40 wt% Zn has been widely used as a key material.

[0003]

However, since the brass key material described above is inferior in corrosion resistance, in practical use, for example, N
Although i plating is indispensable, Ni plating on brass is technically difficult and, as a result, the product yield is unavoidably reduced and the adhesion of Ni plating is also low. Since the plating is peeled off and the brass of the base material is exposed, this exposed brass is apt to corrode, and a significant deterioration in aesthetics is inevitable. On the other hand, on the other hand, there is a tendency for thinner keys (lighter weight) to be required, and therefore, strength that does not deform even if thinned is required, but the brass key material described above can meet this requirement. At present, it does not have high strength.

[0004]

Therefore, the present inventors have
From the above viewpoint, Cu which has excellent corrosion resistance and high strength without requiring Ni plating or the like
As a result of conducting research to develop alloy key material,
In weight% (hereinafter,% means weight%), Zn: 15 to 35%, Ni: 7 to 14%, Mn: 0.1 to less than 2%, Fe: 0.01 to 0.5
%, P: 0.001 to 0.1%, and the balance being a Cu alloy having a composition of Cu and inevitable impurities, the resulting Cu alloy key material has excellent corrosion resistance and high strength. I got the research result that I will be equipped.

The present invention was made based on the above research results, and the reason why the composition of the Cu alloy constituting the key material is limited as described above will be explained below.

(A) Zn The Zn component has a function of improving the strength, but if the content is less than 15%, the desired strength cannot be secured, while if the content exceeds 35%. Since the cold rolling property is deteriorated, its content is 15 to 35%.
I decided.

(B) Ni The Ni component has an effect of improving strength, elongation (toughness), and corrosion resistance, but if the content of Ni is less than 7%, the desired effect of the above effect cannot be obtained. Its content is 1
When it exceeds 4%, the hot rolling property is deteriorated, so the content is set to 7 to 14%.

(C) Mn The Mn component has an action of further improving the effect of improving the strength, elongation and corrosion resistance brought about by the Ni component, but if the content is less than 0.1%, it is desirable for the above action. If the content is 2% or more, the viscosity at the time of melting increases and the castability decreases, so the content is defined as 0.1 to less than 2%. It was

(D) Fe The Fe component has the effect of improving the corrosion resistance, but if its content is less than 0.01%, the desired effect of improving the corrosion resistance cannot be obtained, while its content is 0.5%. If it exceeds 1.0, the corrosion resistance tends to decrease, so the content is set to 0.01 to 0.5%.

(E) The P P component has a function of further improving the corrosion resistance improving effect provided by the Fe component, but if the content thereof is less than 0.001%, desired excellent corrosion resistance can be secured. On the other hand, if the content exceeds 0.1%, the effect of improving the corrosion resistance is saturated and no further improvement is observed, so the content was set to 0.001 to 0.1%.

[0011]

EXAMPLES Next, the Cu alloy key material of the present invention will be specifically described by way of examples. Using a low-frequency groove-type melting furnace, Cu alloy melts having the composition shown in Tables 1 and 2, respectively, are melted in the atmosphere under charcoal coating, and the semi-continuous casting method gives a width of 450 mm x length. S: 2400 mm x thickness: 150 mm, cast into a billet having a dimension of hot rolling start temperature: 800 ° C., hot rolling end temperature:
Hot-rolled under the condition of 450 ℃ to make a hot-rolled sheet with a thickness of 11 mm, and after water cooling, the upper and lower surfaces are 0.5 mm each.
The surface of the hot-rolled sheet is subjected to scale removal, and then the hot-rolled sheet is cold-rolled to form a cold-rolled sheet having a thickness of 2.6 mm, and the temperature is set to 550 ° C. for 1 hour. After being annealed under the condition of holding, further subjected to pickling and polishing, final cold rolling was performed to make the plate thickness 2 mm, so that the Cu alloy key members 1 to 11 of the present invention and the comparative Cu alloy key member 1 6 and a conventional brass key material were manufactured.

[0012]

[Table 1]

[0013]

[Table 2]

The comparative Cu alloy key members 1 to 6 have a content of any one of the constituent components of the Cu alloy constituting the key member (marked with * in Table 2) within the range of the present invention. It is out of the question.

Then, with respect to various key materials obtained as a result, a 96-hour salt spray test (J) was carried out for the purpose of measuring tensile strength for the purpose of evaluating strength and for evaluating corrosion resistance.
IS ・ Z2371) and a 24-hour sweat resistance test (J
The IS.L0848D method) was performed, the maximum corrosion depth was measured in the former, and the surface appearance after the test was observed in the latter. The results are shown in Tables 1 and 2.

[0016]

From the results shown in Tables 1 and 2, the present invention C
It is clear that each of the u alloy key members 1 to 11 has high strength and excellent corrosion resistance as compared with the conventional brass key members, while the comparative Cu alloy key members 1 to 6 are shown. As can be seen from the above, even if the content of any one of the constituents of the Cu alloy constituting the key material deviates from the range of the present invention, it is not possible to secure desired high strength or excellent corrosion resistance. it is obvious.

As described above, since the Cu alloy key material of the present invention has high strength and excellent corrosion resistance, it can be thinned (reduced in weight) in practical use and does not require Ni plating. It has an industrially useful effect such as holding a beautiful metal surface for a remarkably long time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Kumagai 128-7 Ogimachi, Aizuwakamatsu, Fukushima Prefecture Wakamatsu Works, Mitsubishi Shindoh Co., Ltd.

Claims (1)

[Claims] 1. By weight%, Zn: 15 to 35%, Ni: 7 to 14%, Mn: 0.1 to less than 2%, Fe: 0.01 to 0.5.
%, P: 0.001 to 0.1%, and the balance is composed of a Cu alloy having a composition of Cu and inevitable impurities, and a key material made of a high-strength Cu alloy with excellent corrosion resistance.