Salt Water and Metal
The combination of moisture, oxygen and salt, especially sodium chloride, is more damaging to metal than just rust. This combination corrodes, or eats away at, the metal, weakening it and causing it to fall apart. Salt water corrodes metal five times faster than fresh water does and the salty, humid ocean air causes metal to corrode 10 times faster than air with a normal amount of humidity would. Bacteria in ocean water also consumes iron and what is excreted turns to rust.
Electrochemical Corrosion
One form of corrosion that occurs when metal and salt water get together is called electrochemical corrosion. Metal ions dissolve in water and salt water conducts electricity and contains ions, which attract ions from other compounds. During electrochemical corrosion, electrons from other compounds are attracted to the metallic ions. Salt water attacks the metal and corrosion occurs.
Anaerobic Corrosion
Anaerobic corrosion is the second type of corrosion that occurs when metal is exposed to salt water for an extended period of time. Deposits that contain sulfates surround the metal as it sits in salt water. Hydrogen sulfide is produced which corrodes metals. At the same time, bacteria grows in the salt water which used hydrogen to corrode the metal as well. Between the ions, sulfates and bacteria, metal is attacked from all angles when it is in salt water.
Read more: The Effects of Saltwater on Metals | eHow.com
The Effects of Saltwater on Metals | eHow.com