Titanium in the marine environment

Titanium and its alloys are immune to general or crevice corrosion in sea water at all temperatures below about 230\deg F. Crevice corrosion becomes increasingly likely for unalloyed titanium as temperature is increased above 110\deg C TiCode 12 and Ti-.2Pd are advanced corrosion alloys that avoid this problem. These alloys do not crevice corrode even in saturated brines at 250\deg C and pH=4. In ambient sea water, fouling by organisms does not induce pitting. Titanium and its alloys are also resistant to erosion. Certain titanium alloys offer very high strength to density ratios, on the order of 10^{6} inches or more. For one or more of these reasons, titanium has found extensive application in pumps, plumbing, heat exchangers, desalinization units, offshore well logging equipment, deep diving research vehicle hulls, and sonar plates. Potential growth areas include offshore well risers and submarine hulls. Titanium is at present the only material qualified for OTEC heat exchangers.