JPS6053734B2 - Mesh band for mobile watch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mesh band for a wristwatch that has excellent corrosion resistance, mechanical properties, and workability.

Conventionally, exterior parts for wristwatches have been made by using brass or nickel silver as a material and applying metal plating to the material, or by using austenitic stainless steel, such as 18Cr-8Ni stainless steel, as a material and polishing the surface. It was served as a.

However, in the case of exterior parts for wristwatches, due to their complex shapes, when the plating is finished, the plating does not adhere well to the gaps during carrying, and sweat, seawater, etc. act on the gaps and cause corrosion, which significantly reduces the value of the product. There were cases where this was done. The above-mentioned phenomenon was especially noticeable in exterior parts such as mesh bands. In recent years, Ni-based alloys have been used to solve these corrosion problems, but although the current Ni-based alloys can achieve most of their goals in terms of corrosion resistance, their workability is extremely poor, causing problems such as bands, etc. Parts that require a large number of processes are expensive, making it impossible to provide products with excellent quality at low prices.

The present invention obviates the drawbacks of the prior art as described above.

That is, the present invention provides a highly corrosion-resistant material that can replace conventional alloys such as austenitic stainless steels that maintain corrosion resistance through Cr, and also improves the workability of Ni-based alloys to provide inexpensive, high-quality mesh bands. It is something. The alloy of the present invention, which is intended to improve the corrosion resistance and mechanical properties after plating of complex parts such as mesh bands for mobile watches and which have poor plating coverage, and to provide excellent workability, consists of the following chemical components.

That is, in weight ratio, Mo (molybdenum) 15 to 30% W (tungsten) 1 to 5% Fe (iron) 5% or less Cu (copper) 3% or less Ti, V, Ta, Zr (one or more types) The remainder is 1% or less of Ni and unavoidable impurities.

Next, the reason for limiting the addition range and composition range of each component will be described.

Ni is a useful base metal that has very excellent corrosion resistance, sufficiently dissolves Mo and W, and has significant characteristics in strengthening the alloy and improving corrosion resistance.

Mo is a particularly important additive element in this alloy because of its relationship with Ni mentioned above.

In Ni-Mo alloy, when Mo becomes 15% or more, 10%
At HC 170°C, the corrosion resistance is almost the same as that of the original. In the present invention, the effect of adding MO to this Ni-MO alloy is taken into consideration, and the lower limit of MO addition is set at 15%. The above effect is enhanced by increasing the amount of MO added, but if it exceeds 30%, processability deteriorates and dissolution becomes difficult, so it is limited to 15 to 30%. Since Fe tends to cause red rust,
The addition should be suppressed as much as possible, but adding it in an amount of 5% or less to improve workability on a Ni-MO basis will not cause a decrease in corrosion resistance.

Like MO, Cu is a Ni-based element that exhibits an excellent corrosion resistance improvement effect and also improves Au plating properties.
Similar to the phenomenon in which the corrosion resistance decreases due to an increase in the amount of Cu added in Monel, the upper limit is regulated to 3% in the present invention.

W is a strength-enhancing element in the present alloy, has an excellent elastic modulus by itself, and is an element that significantly increases the strength of solid solution.

This effect is further enhanced by the combined effect with MO, so the effect becomes apparent at 1%, and a sufficient effect can be obtained at 5%.
Furthermore, since one or more of Ti, ■, Ta, and Zr are added in an amount of 1% or less as grain refining elements to improve the workability of Ni-based alloys, the effects aimed at by the present invention are impaired. We can provide materials with excellent workability without any problems.

Next, the usefulness of the present invention will be explained based on Examples.

Gold or all of these alloys can be used as precious metal plating to obtain a decorative effect. The plating thickness is Au
-2 to 10μ for CO alloy plating, Au-Ni-1n
In this case, 0.1 to 4μ is optimal. [Example 1] In terms of weight ratio, MOl: 9.3%, W: 3%, CUl. 5%, Fe
．． A mesh band for a wristwatch was prepared from a wire rod of 0.6 wtφ using the present invention alloy consisting of 5% Ti (5V), a total of 0.7%, the balance Ni and unavoidable impurities as a raw material.

This band and the 17Cr-15Ni O. -We created a band made of stenitic stainless steel. This was activated by electrolytic treatment at 5 A/Ddl for 36 seconds in an aqueous solution of nickel sulfate 100 y/el and concentrated hydrochloric acid 50 ml/e, followed by 24K gold strike plating, 4μ Au-CO alloy plating, and Au-Ni-In. Alloy plating 2p was applied. Next, when a corrosion resistance test was conducted by immersing the band in artificial sweat and 5% saline solution for 7 days, in the case of a band made of stainless steel, the plating on the band surface peeled off and significant red rust occurred on the entire surface. However, the
No peeling was observed, and no rust was observed at all. In addition, regarding the mechanical properties of the product of the present invention, the tensile strength was 58k9/Tln2 and the elongation was %. [Example 2] In terms of weight ratio, MO27.5%, W4%, Fe4.5%,
An alloy consisting of 2.5% CU, 0.5% in total of Ta and Zr, and the balance Ni and unavoidable impurities was prepared in the same manner as in Example 1, and then this band and a mesh band made in the same manner were prepared. A band made of a Ni-based alloy consisting of 5% Crl, 7% Fe, and the balance Ni was activated and plated in the same manner as in Example 1, and a corrosion resistance test was conducted. , and green rust appeared in dots, whereas in the band according to the present invention, no abnormality was observed at all.

The mechanical properties of the product of the present invention were also excellent, with a tensile strength of 63k9/WfL2 elongation of 40%. Further, in comparison of the number of processing steps, the alloy of the present invention can be manufactured with a band production time of 50 to 70% compared to austenitic stainless steel and Ni-based alloys of 15Cr-7Fe, resulting in lower costs.

As described above, the present invention has a Ni-MO base with Fe,
By adding W, Cu, Ti, V, Ta, and Zr, it is extremely useful in providing a mesh band for a portable watch that has excellent corrosion resistance after Au plating, excellent mechanical properties, and good workability.

Claims (1)

[Claims] 1 Mo 15-30%, W 1-5% in weight ratio
, Fe5% or less, Cu3% or less, Ti, V, Ta, Zr
1. A mesh band for a portable watch, characterized in that the material is made of an alloy consisting of 1% or less of one or more of the following, the balance being Ni and unavoidable impurities, and is plated with a metal of gold or a gold alloy.