Fretting wear in seawater

Fretting tests of bearing steel (SUJ-2) and ceramics (Al₂O₃ and Si₃N₄) were carried out in the following environments: air, deionized water, 3.07% NaCl solution, synthetic seawater and natural seawater. Also, investigations to determine the optimum fretting wear resistant material for ships, marine equipment and offshore structures were conducted. The results showed that (1) the corrosion products formed in seawater behaved as a lubricant and reduced the fretting damage at large amplitudes, but the fretting damage was not greatly influenced by the different environments at very small amplitudes (such as 14 μm), (2) instead of natural seawater, synthetic seawater was adequate for the investigations of fretting wear, but 3.07% NaCl solution was found not to be and (3) the ceramic Al₂O₃ was a potentially useful material against fretting wear under light loads in seawater.