Analysis of Corrosion Damage on Propulsion Shafts of Marine Vessels

摘要

The nickel aluminum bronze propulsion shafts of some marine vessels have been found to suffer wear and corrosion damage at the bearing/journal interface. This damage was manifested as a series of shallow circumferential grooves varying in depth from 0.001 to 0.010 inch (0.025 to 0.25 mm) as well as an overall reduction in shaft diameter. This paper presents some mathematical analysis to demonstrate how a non-existent (or poor) shaft ground can impact the magnitude of stray currents that can possibly explain the severe corrosion observed on these shafts. Other possible causes are also examined.