The reason why white frost appears after galvanizing white or blue-white passivation is mainly related to the following factors:
(1) The material of the substrate is too bad and it has been heavily rusted
(2) excessive corrosion caused by pickling of the workpiece;
(3) The degreasing and rust removing process of the workpiece is not in place;
(4) The corrosion products left on the surface of the workpiece after pickling and carbon dust have not been cleaned;
(5) Incomplete cleaning before and after passivation;
(6) plating is too thin;
(7) There is no adequate drying after passivation.
Since the electroplating factory that provided the consultation was located in the outer suburbs, the author wrote a letter to the plant about the above-mentioned reasons that may cause the frost. The letter came soon to find the answer from Article (5), which solved the problem of long-term deactivation of the white frost.