1. Check the defects of the galvanized coating through appearance:

(1) The correct color passivation film should be a rainbow color leading to green and be semi-bright to full-bright. The passivation film is uniform, tight, meticulous, and has a natural color. There is no too-thick or too-light color and no large red spots, gray, or yellowish brown.

2) In the recesses and dead corners of more complex parts, it is allowed to have a passivation film with a slightly poor appearance, or a dull but colored passivation film. However, it is not allowed to expose the underlying metal or make it black or rusty.

(3) A small amount of water stains are allowed on the surface of the electroplated finished product, but dry stains from the passivation solution (in other words, chromic acid spots caused by poor cleaning) are not allowed. A small amount of scratches are allowed, but the scratches should not affect the appearance, and the base metal should not be exposed. Shelling, bubbling, and obvious yin and yang sides are not allowed.

2. Check the defects of the galvanized layer through bonding force:

(1) Use a piece of forest paper, hold your finger down, and wipe it back and forth on the plated parts about ten times. There should be no peeling off of the passivation film or a change in the color of the passivation film.

(2) If the plated parts are slightly impacted, there will be no peeling of the coating. According to requirements, some products may be deformed 180°, and there should be no coating peeling off.

(3) Products that require hydrogen removal should be dried in a 200°C oven for half an hour before passivation of the plated parts. There will be no blackening, loosening, or peeling of the coating.

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