This process is an environmentally friendly, high-performance and high-corrosion trivalent chromium passivation process. It is suitable for the passivation of acid zinc, alkali zinc, zinc nickel, and zinc iron. According to different requirements of customers, the passivation color can be as follows: Silver white, blue, color, black, army green and color green, suitable for barrel plating and rack plating, passivation solution does not contain hexavalent chromium, and complies with EU RoHS and ELV regulations.