Coastal and offshore PV systems suffer severe chloride corrosion. Ordinary SUS304 fasteners pit and seize within 1-2 years, bringing high maintenance cost. This article grades corrosion environments and matches proper materials per GB/T 10125 salt spray standard.
| PV Project Location | Chloride Corrosion Level | Min Salt Spray Hours Without Red Rust | Recommended Material / Coating |
| Inland Mountain PV | Low | 500h | SUS304 Natural Passivation |
| Riverside & Lake PV | Medium | 1500h | SUS316L Stainless Steel |
| Offshore / Marine PV | High | 5000h | 2205 Duplex Stainless Steel |
1. EPDM insulating gaskets mandatory between Zn-Al-Mg carbon steel brackets and stainless bolts to block galvanic circuit; 2. Avoid direct contact between carbon steel frames and duplex steel fasteners; 3. Full 2205 matching is the optimal solution for marine PV stations.
1. Vapor phase anti-rust packaging for offshore fasteners during sea transportation; 2. Weather-resistant seal coating applied on exposed bolt and weld areas after installation; 3. Annual inspection focused on tide-submerged bottom bracket fasteners.