“防腐、耐用、环保”等优点深得人心，但因色彩冰冷、单调，应用领域受到极大限制。 Stainless steel has won the hearts of people because of its "anti-corrosion, durability, and environmental protection", but because of its cold and monotonous color, the application field is greatly limited. Colored stainless steel came into being. It not only maintains the physical, chemical, and mechanical properties of the original stainless steel, but also has colorful and durable colors. Its appearance meets the modern people's requirements for color diversification, and its applications are increasingly wide.
1. Origin of colored stainless steel
Colored stainless steel is neither obtained by spraying paint or plastic on steel, nor is it obtained by dyeing like colored aluminum. The colored stainless steel itself is colorless. The color is obtained due to a layer of colorless and transparent dense oxide film on the surface. When light strikes the film, the reflected light and the refracted light passing through the film result in light interference . The color of the colored stainless steel surface depends on the chemical composition of the surface oxide film, the structure, the finish, the thickness of the film, and the incident light.
2. Colored stainless steel is divided into the following types:
(1) Chemical oxidation coloring method: It is the color of the film formed by chemical oxidation in a specific solution. There are dichromate method, mixed sodium salt method, sulfurization method, acid oxidation method and alkaline oxidation method. Generally, the "Inco method" (INCO) is used more, but to ensure the uniform color of a batch of products, a reference electrode must be used to control it.
(2) Electrochemical oxidation coloring method: The color of a film formed by electrochemical oxidation in a specific solution.
(3) Ion-deposited oxide coloring method: Put the stainless steel workpiece in a vacuum coating machine for vacuum evaporation plating. For example: titanium-plated watch cases and watch straps are generally golden yellow. This method is suitable for high-volume product processing. Because of the large investment and high cost, small batch products are not cost-effective.
(4) High temperature oxidation coloring method: It is to immerse the workpiece in a certain molten salt and keep it at a certain process parameter, so that the workpiece forms an oxide film with a certain thickness and presents various colors.
(5) Gas-phase cracking and coloring method: it is more complicated and it is rarely used in industry.
3.Application of colored stainless steel
Colored stainless steel has gradually become a very good decorative material due to its brilliant colors, and it is decorated with luxurious and luxurious quality. In addition, the color stainless steel has better resistance to salt spray corrosion than ordinary stainless steel, and can withstand salt spray corrosion for more than 10 years. Its color surface layer can withstand temperatures of 200 ° C and can resist color change for more than 30 years.
Colored stainless steel is an environmentally friendly decorative material, does not contain organic matter such as methanol, has no radiation, is corrosion-resistant and durable, and has a wide application field. At present, it is mainly used for building exterior wall and window frame decoration, such as large building decoration (bus station, train station, subway station, airport, etc.), hotel and building business decoration, public facilities, new home decoration; in the arts and crafts industry, colored stainless steel Combining with printing, it can adopt the process of etching and grinding and dot method to produce three-dimensional embossed murals and hanging screens that will never fade. It can also be used in elevators, hardware appliances, kitchen appliances, cabinets, advertising signs, daily necessities. Etc. can greatly increase the added value of the product and have obvious market competitive advantages.