A time-dependent corrosion wastage model for seawater ballast tank structures of ships

For assessment of time-dependent reliability or risk of aging ship structures, it is essential to have a mathematical model which provides the statistical characteristics (mean, variance, distribution) of corrosion wastage as a function of time (i.e., ship age). The aim of the present work is to develop such a model for low alloy carbon steel plates used for the structure of seawater ballast tanks in ships. Measurement data of structural wastage due to corrosion for such ship steel plates is collected and the statistical characteristics of corrosion loss and rate are quantified by statistical analysis in terms of ship age. The results and insights developed in the present study will be useful for predicting the wastage of corrosion in seawater ballast tank structures of ships. They will also be useful for designing corrosion tolerant structures subjected to the seawater environment.