Enclosed atmospheric corrosion in ship spaces

The process of enclosed atmospheric corrosion within ship spaces is investigated. It is proposed that corrosion rates are influenced mainly by three parameters: time of wetness, salt deposition and temperature. Assuming atmospheric corrosion to be primarily cathodically controlled, it is shown that, as a first approximation, the rate of atmospheric corrosion is linearly proportional to both temperature and salt deposition. This is shown to be consistent with available experimental data. An equation is presented for the prediction of corrosion rates within ship spaces exposed to an enclosed atmosphere, such as cargo holds and ballast tanks, on a per voyage basis. The influencing parameters identified in this study, and the proposed model, provide a starting point for future probabilistic modelling of one component of ship corrosion, namely, enclosed atmospheric corrosion.