All metals including gold will corrode if subjected to salt water long enough. You could wipe this thing down everyday and it will still corrode. Different metals corrode in unique ways, some tarnish, some pit, some crack, some flake, some turn into white power but they all corrode. It is a charateristic of metal and cannot be controled only managed. All it takes is one micron of sodium to get past the coating and corrosion will start. The only way to manage it is to periodically sand and recoat or electrically energize the part to break the anode to cathode path, but still this is only a treatment not a cure. After spending my life in the USN combating this problem I can easily tell you that all metals will corrode if exposed to saltwater long enough. I have seen it.
Modern aircraft use a wide variety of metals and composite materials.
So much so that there are specific Corrosion Control programs and workcenters dedicated and implemented in Naval Aviation squadrons to combat corrosion. Coatings whether they be plated, epoxy based or baked i.e powdercoating (some landing gear components) will deteriorate under UV light (most salt water aquarium lighting) and saltwater. The metals used in our jets and ships range from Stainless steel, Aluminum, Magnesium, Iron and Titanium, Gold, Silver, Platnum and Mercury, they will all react in adverse ways if exposed to salt water long enough. Intergranular, exfoliation, filiform, microbiological, stress fatigue or direct suface oxidation all metals corrode.
Heres why:
http://www.efunda.com/materials/corrosion/corrosion_basics.cfm