An approach to predicting corrosion fatigue for marine applications

Abstract

Corrosion fatigue is one of the main failure mechanisms of components working in corrosive environments. As a result, the assessment of this phenomenon and taking it into account is of paramount importance in designing such components and particularly in the marine sector where the structural elements are generally designed to have longer life cycles. However, being highly time-demanding due to requiring to be done slowly, conducting corrosion fatigue tests is a serious challenge in marine structures. In this study, at first, the performance of two available methods for accelerating corrosion fatigue tests (using pre-corroded specimens as well as artificially-pitted ones) were compared for a steel with offshore applications. The idea here was to find a way to round out the obligation for conducting the long corrosion fatigue experimental tests with low frequencies. Moreover, extensive finite element (FE) studies have been carried out to predict corrosion fatigue life without the necessity to conduct corrosion fatigue tests and just based on the data obtained from fatigue S-N curves. The numerical and experimental results were in good agreement which means that FE models can effectively be used as a reliable tool to reduce the need for conducting long corrosion fatigue tests.