Salt spray testing uses a fine mist of saltwater to mimic tough, corrosive conditions—like ocean air. Here's how common metals hold up:
🔹 1. Carbon Steel
Rusts quickly in salty air
Forms red rust that doesn’t protect the surface
Needs coating to last longer
🔹 2. Stainless Steel
Has a protective layer to resist rust
Can still get pitting if scratched
316 grade resists salt better than 304
🔹 3. Aluminum
Forms a natural oxide layer for protection
Can still get small pits in salty conditions
Lightweight and good for outdoor use
🔹 4. Zinc / Galvanized Steel
Protects steel by corroding first
Forms white rust, which is protective
Great for outdoor and marine use
🔹 5. Copper & Alloys (Brass, Bronze)
Rusts slowly and builds a greenish patina
Good for decorative and durable uses
Some types may have special corrosion issues
🔹 6. Magnesium Alloys
Corrodes fast in salty air
Must be coated or treated
Used in aerospace and lightweight parts
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