Common Surface Treatment Methods?
Hot-dip galvanizing (HDG), cold galvanizing, powder coating, spray painting, blackening, sandblasting.
Differences between hot-dip galvanizing and cold galvanizing?
Hot-dip galvanizing: Zinc layer thickness 50-100μm, long corrosion protection life (10-15 years), suitable for outdoor/humid environments;
Cold galvanizing: Zinc layer thin 5-15μm, low cost, suitable for indoor/light-load applications.
Key Points for Pre-treatment Before Powder Coating?
Thoroughly remove oil and rust (shot blasting/sandblasting + pickling), control pickling concentration and time to avoid over-corrosion.
Rust Prevention Solution Selection?
Outdoor/Humid: Hot-dip galvanizing/powder coating + primer;
Indoor dry: Spray painting/blackening;
Precision parts: Cold galvanizing/nickel plating.
Key Points for Weld Corrosion Protection?
Re-remove rust after welding; the weld corrosion protection layer thickness should be 20% greater than the substrate.