I. Natural Rust Layer Optimization (For Weathering Steel)
1. Natural Rusting Method
Principle: Outdoor exposure forms dense rust layer via alloy elements (Cr, Cu, Ni) over 6–12 months.
Operation: Place outdoors; avoid surface impurities.
Scenarios: Rust-texture needs (sculptures, railings); low-corrosion environments.
2. Artificial Rust Acceleration
Principle: Rust accelerators shorten formation to 1–2 weeks; avoid rust powder loss.
Operation: Clean surface → apply accelerator; optional stabilizer.
Scenarios: Mass production (lawn mower garages); fast rust appearance.
II. Coating Protection (Physical Barrier)
1. Weather-Resistant Coating
Principle: Resins (fluorocarbon, acrylic) + anti-rust pigments form dense barrier.
Types: Fluorocarbon (15–20 years service); acrylic (cost-effective); epoxy primer + topcoat.
Operation: Derust → apply 2–3 coats of primer/topcoat.
Scenarios: High weather resistance; non-rust appearance (metal cabinets).
2. Hot-Dip Galvanizing (For Steel)
Principle: Molten zinc forms coating (sacrificial anode protection).
Operation: Degrease → derust → dip zinc; coating 50–100μm.
Scenarios: Humid/salt spray environments (brackets, columns).
III. Surface Passivation/Sealing (Auxiliary)
1. Passivation Treatment
Principle: Passivator forms thin film to stabilize galvanized layer/rust layer.
Operation: Post-coating/galvanizing → dip/spray passivator.
Scenarios: Reinforce galvanized products; stabilize artificial rust.
2. Sealant Coating
Principle: Transparent sealant (acrylic, silane) preserves appearance and blocks corrosion.
Scenarios: High-appearance needs (rust-colored ornaments).
Core Difference Comparison
