1. Process method: degreasing -- cleaning -- passivation -- washing -- stabilization -- washing -- neutralizing -- washing -- sealing -- drying.

     1) No neutralization process is required for workpieces with complex structures such as blind holes and slits.

     2) The sealing can be selected according to the requirements of salt spray resistance.

     3) If there is no neutralization process, the rinsing must be clean.

2. Process description:

   (1) Degreasing Select a degreasing agent according to the grease on the surface;

   (2) Use of passivation stock solution; treatment temperature: 65-70 degrees; treatment time: about 30 minutes, if the time is appropriately extended, the corrosion resistance can be improved.

   (3) Stable use of stock solution; treatment temperature: 65-70 degrees; treatment time: about 30 minutes, and appropriate extension of time can improve corrosion resistance.

   (4) Neutralization Soak in 5% sodium hydroxide for 1-2 minutes;

   (5) Washing with tap water or pure water, rinse for 2-3 minutes; it is recommended not to use river water or purified water.

   (6) Enclosed Bath ratio: 10%; Treatment temperature: normal temperature -45 degrees; Treatment time: generally 3-5 minutes.

   (7) Drying Natural drying or drying, the recommended drying temperature is 80-100 degrees, not exceeding 120 degrees.

   (8) Maintenance: It is forbidden to bring alkaline substances into the passivation tank, and try not to bring water into the passivation tank to maintain the service life of the passivation solution;