Has the thickness of the workpiece been measured?
Normally, if it is cyanide galvanizing, passivation should be very good to do, if so many kinds of passivation agents have not solved the problem, it may be the plating itself has a problem or the passivation process failure. First, was there any light before passivation? If the coating is too thin, the galvanized layer can be dissolved directly when the light is emitted, and the subsequent treatment in this way is of no use.
If the surface of the workpiece is bright after the light, then look at the concentration of the passivation agent, PH, passivation time, temperature and other parameters are not within the normal range, if these are OK, there should be no bad passivation problem.
There is also a problem, if the galvanized layer is not passivated for too long, the surface will also generate a layer of zinc oxide, which will also affect the passivation behind.
If the time from the workpiece to passivation is too long, it will also make the passivation layer matte is not bright.
Is there a picture? The anodizing process has multiple cleaning, oil removal, cleaning, pickling, alkali neutralization, water washing, oxidation and alkali neutralization and water washing. Each step should be cleaned until there is no residual night, and the anodized sample will not be dirty like water stains. The parameters of anodizing should also be controlled appropriately to avoid burning and fogging.
If it's good after oxidation, you use it for a while and there's dirt on it, usually grease or something, you get some alcohol and acetone, you clean it with ultrasound and try it.