First, the process
Baskets → degreasing → cold water washing 1 → pickling light → cold water washing 2 → surface conditioning → cold water washing 3 → rust-proof phosphating → post-treatment
Second, the Phosphating preparation process and precautions
(A) loaded basket
Can use multi-level or multi-format plastic basket (basket). The purpose is to leave gaps between the phosphated parts.
Neutral degreaser: 5%;
Liquid temperature: 60 ~ 90 ℃ (ultrasonic equipment without heating);
Time: to remove the surface oil is appropriate.
(C) cold water wash 1
Time: not less than 1 minute (depending on the parts surface water film uniform continuous);
Mode of operation: basket (basket) need to move up and down in the sink to enhance the cleaning effect
(D) pickling light
Pickling liquid concentration: 3% HNO3;
Time: uniform surface gloss color appropriate;
A light tank requirements: To acid
(E) cold water wash 2
Washing method: water rinse
Time: not less than 1 minute (be sure to wash the residual acid)
Mode of operation: pickled light basket moved to sink cold water washing 2 hours, faster, so as to avoid corrosion of parts.
(F) surface adjustment
Oxalic acid: 25g / L;
Temperature: room temperature
Time: 1 minute
(Seven) cold water wash 3
Washing method: two countercurrent rinsing
(H) rust phosphating
Phosphating: Antirust phosphating solution concentration HH951 special antirust phosphating solution: water = 1: (7 ~ 9)
Anti-rust phosphating solution capacity: 15 ~ 20m2 / kg
Phosphating fluid maintenance: the use of regular adjustments to maintain its concentration
1. After anti-rust phosphating process do not wash, the natural dry or hot air dry (can rust one year).
2. Long-term rust-proof products, rust-proof phosphate, dried, and then anti-rust anti-dehydration oil, and drying or drying. Finally, you can not see the oil on the surface, but with a layer of rust-proof film. Drainage anti-rust oil, water should be used to drain tank.
Article from NdFeB Industry Network