| 摘要 |
PROBLEM TO BE SOLVED: To reduce concentration of hexavalent chromium ions generated in trivalent chromium plating liquid.SOLUTION: A trivalent chromium plating system comprises: a main tank 2 for applying trivalent chromium plating; a sub tank 3 which circulates trivalent chromium plating solution between the main tank 2 and the subtank and supplies the trivalent chromium plating solution to the main tank 2; and a regeneration apparatus 4 in which the trivalent chromium plating solution in the sub tank 3 is circulated. The trivalent chromium plating solution contains trivalent chromium ions and reducing agent, the regeneration apparatus 4 comprises a regeneration tank 5 to which the trivalent chromium plating solution after trivalent chromium plating is supplied, and a cooling tank 6 to which the trivalent chromium plating solution is supplied from the regeneration tank 5. Temperature of the regeneration tank 5 is set higher than trivalent chromium plating temperature, and temperature of the cooling tank 6 is set to the trivalent chromium plating temperature or higher and lower than the temperature of the regeneration tank 5. |
