Currently, trivalent chromates include chromate, monochromate, and ferrite, etc. (chromic acid is silver-white in color), and there has never been a yellow color like that of hexavalent chromate. In the past, hexavalent chromium plating was mostly used for yellow products. However, in consideration of the global environmental issues, Heiwa Kasei in Japan has now developed a surface treatment technology that gives a yellow or red color like hexavalent chromate even on trivalent products.
Characteristics of trivalent yellow.
1、Like the yellow or red interference color of hexavalent chromate!
2、Corrosion resistance equivalent to trivalent chromate: no white rust for 72 hours, no red rust for 120 hours!
3、No hexavalent dissolution will be detected!
4、If used together with trivalent chromate, it can be used to distinguish subtle differences in size and thread.
