JPS6169981A - Ornamental member - Google Patents

Abstract

PURPOSE:To obtain an ornamental member having excellent corrosion resistance and ornamental effect by forming an oxide layer of a black or green color on the surface of a base alloy composed of austenitic stainless steel. CONSTITUTION:A base alloy consisting of austenitic stainless steel is manufactured and the surface layer thereof affected by working is removed by pickling, honing or other processes. Then the base alloy is subjected oxidation treatment in an oxidizing atmosphere at about 1,000 deg.C for about 2.5hr, or at about 1,250 deg.C for 0.1-1hr, to form an oxide layer of a black color on the surface thereof; or is subjected to oxidation treatment at a temp. lower than the said temp. to form an oxide layer of a green color on the surface thereof. The thickness of the oxide layer is 2-20mu.

Description

[Detailed description of the invention] [Technical field of invention] TECHNICAL FIELD The present invention relates to improvements in decorative parts.

[Technical background of the invention and its problems]

Conventionally, materials for various decorative items such as metal eyeglass frames and accessories have been nickel silver, phosphor bronze, brass, stainless steel,
Nickel-chromium alloys (hereinafter abbreviated as nichrome alloys) are available in many varieties, including aluminum alloys, and are used for various parts of eyeglass frames and other decorative items, depending on their properties. However, nickel silver and phosphor Eyeglass frames and accessories made from materials such as bronze and brass corrode with sweat and generate bronze when used for long periods of time, so high-quality frame materials are plated with rhodium or gold, and general frame materials are plated with chrome. It is necessary to apply plating, etc. Compared to this, stainless steel, nichrome alloy,
Aluminum and other materials do not corrode due to sweat like the aforementioned copper-based alloys, but these materials were not originally developed as decorative materials and are mainly used for corrosion-resistant structural materials and electric heating materials. K, which is used as a material for things that require decorativeness such as eyeglass frames and accessories, has various problems. In other words, when stainless steel, nichrome alloy, aluminum, etc. are finished polished to give them the luster characteristic of metals and to enhance their decorativeness, surface flaws occur due to inclusions in the material that are present during manufacturing and processing of the material. Since it is difficult to obtain a perfect mirror surface without defects, spiders, or scratches, it is difficult to industrially supply parts made of this type of metal material as having high decorative value.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks and provides a novel decorative member based on austenitic stainless steel, which has significantly improved decorative properties.

[Summary of the invention]

That is, the decorative member of the present invention is characterized by having a black or green oxide layer formed on the surface of a base alloy made of austenitic stainless steel, and has excellent corrosion resistance and decorative properties. It is something.

K that causes the formation of the oxide layer on the surface of this base alloy is:
900 N in an oxidizing atmosphere (e.g. in a steam stream)
Oxidation treatment may be performed at 1300°C for 0.5 to 5 hours. The oxide produced on the surface of the base alloy by this treatment consists of iron-chromium spinel oxide. In order to extremely increase the adhesion strength of this oxide layer to the base alloy, it is preferable to include aluminum in the base alloy. In addition, if you want to obtain highly reliable bond strength, it is recommended to remove the damaged layer on the surface of the base alloy, which occurs during the component manufacturing process, by pickling, honing, etc. before oxidation treatment. It is better to process it. The color of the oxide produced by this treatment is blackish and amber, 1
When processing at around 000℃, it takes around 2.5 hours, 125
When the temperature is 0°C, a stable oxide layer can be obtained by treatment for 0.5 to 1 hour. Further, if the oxidation treatment is performed at a temperature lower than the above temperature range, a greenish oxide is produced. Note that whether to generate a black oxide or a green oxide may be arbitrarily selected depending on the r-din of the ornament.

The black or green oxides produced by high-temperature oxidation are chemically stable and have excellent sweat corrosion resistance. Although the surface of this oxide layer has microscopic irregularities when viewed under a microscope, it has sufficient decorative value as black or green eyeglass frames, jewelry, and other ornaments. ) To improve the decorative properties, the surface of the oxide layer can be polished to a mirror finish. This polishing is carried out in normal polishing because the oxide layer has a thickness of 2 to 20 μm and there is a risk that the oxide layer will be removed if rough polishing is performed using an emery puff etc. → Emery puff polishing → Nidelpa 7 polishing → Regardless of the cotton puff polishing process, it is preferable to immediately perform finishing polishing M using a cotton puff. Furthermore, if an oil-based abrasive such as aluminum oxide or chromium oxide, which has abrasive ability, is used as the abrasive used in cotton puff polishing, the surface of the oxide layer can be efficiently finished to a mirror finish. Note that the above polishing is polishing the surface of the oxide layer, and even if there are inclusions in the material (base alloy) as described above, there is no problem of causing defects, and mirror finishing is performed in this way. [Also, the corrosion resistance of the oxide layer does not change.

[Embodiments of the invention]

The present invention will be explained in detail below.

Commercially available 5uds 304 (18% chromium in terms of ffi amount)
, containing 8% nickel) and SO8316 (chromium 25
%, nickel 20 t) were processed to fabricate each part of an eyeglass frame, and these parts were heated at 1250° C. for 4 hours to form a black oxide layer with a thickness of 7 μm on the surface. This sample was mixed with 1.0% salt, 0.2% urea, 0.03% sodium sulfide,
Sugar 0.02%, ammonia water 0.02%, lactic acid 0.1
%, residual) was tested for corrosion by immersing it in an artificial juice solution consisting of water at a temperature of 30°C and at a temperature of 50°C, 200 times at 10-minute intervals and leaving it in the air. No change was observed. Next, a chromium oxide abrasive was applied to the t-cotton puff on the surface of the oxide layer of the sample, and the sample was polished to a mirror finish. This sample was also tested under the same conditions using the aforementioned artificial juice, but no changes were observed, confirming that it has extremely excellent corrosion resistance.

In addition, the mirror-finished sample had a black sheen and had extremely good decorative properties. Furthermore, we tested the spring properties and found that even when an oxide layer was formed, austenitic stainless steel did not lose its good spring properties, making it advantageous for eyeglass frame parts that require supple elasticity, such as temples. Ta.

〔Effect of the invention〕

Since the decorative member of the present invention is as described above, it has extremely excellent corrosion resistance and decorative properties.

/1M71

Claims (1)

[Claims] A decorative member characterized by being made of a material in which a blackish or greenish oxide layer is formed on the surface of a base alloy made of austenitic stainless steel.