12.Colored stainless steel
The stainless steel color process was successfully developed by the International Nickel Corporation (INCO) in the 1970s, and many companies have licenses to use this process.
As explained earlier, the reason why stainless steel does not rust is because of the chromium oxide film on its surface.
The color process is to use this layer of film to form a specified color.
Since stainless steel uses this film that always exists, it neither fades nor does it require frequent maintenance like paint.
Color stainless steel can also be formed, even in sharp bends, it will not have any adverse effects on the color.
Regarding the influence on the corrosion resistance, the test shows that the corrosion resistance is enhanced after the process is adopted.
The process is closely related to the operating time, and the color will change with time. The order of color change is brown, gold, red, purple and green.
A major feature of this process is that its final appearance can reflect the original surface of the material, that is, a mirror or polished surface will produce a strong metallic luster, while the color of the matte surface is matte.
The process is to immerse stainless steel in a solution tank. The solution should preferably contain 250 grams of Cr2O3 per liter, or 490 grams of sulfuric acid per liter. The temperature range is 80″85°C. The soaking time depends on the required color, at most not More than 25 minutes.
After rinsing the steel plate with clean cold water, it is placed in a liquid with a concentration of 250 g/1 liter of chloric acid and 2.5 g/1 liter of phosphoric acid at room temperature for cathode treatment. The time is about 10 minutes, and the current density is 0.2″ 0.4 A/dm2.
To prevent damage, the hardening treatment is performed immediately after the color treatment, and then rinsed and dried in hot water.
13. Mixed surface processing
Patterns can be added to the colored stainless steel. The developed proprietary technology includes removing the “protruding” parts with corundum belts. In this way, the final result is to combine the natural beauty of the steel plate with the colors of the colored patterns.
This kind of surface is not easy to leave handprints, and is especially suitable for interior decoration.
Polishing manufacturers can provide samples for surface processing.
14. Etching surface processing
Mark the pattern on the surface of the steel plate through the coating process, and then immerse the steel plate in ferric chloride acid solution (grade o) to etch away the uncoated part, forming a beautiful pattern on the surface of the stainless steel.