Fatigue Behaviour of EN 1.4062 Lean Duplex Stainless Steel with Crevice Corrosion in Seawater

Abstract

The research investigates the corrosion–fatigue performance of EN 1.4062 lean duplex stainless steel subjected to crevice corrosion in natural seawater, addressing current fatigue design limitations that implicitly assume corrosion‐free conditions. Specimens were exposed to controlled crevice conditions in flowing seawater at 30°C and subsequently tested under constant‐amplitude cyclic loading. The results were presented in Wöhler (S–N) form, and a probabilistic S–N curve was developed together with the corresponding characteristic fatigue strength in accordance with Eurocode guidelines. An initial two‐parameter Weibull reliability assessment was conducted, employing four different parameter estimation methods to identify the most statistically consistent detail category, relative to EN 1993‐1‐9. The experimental study is complemented by numerical models developed in Abaqus to quantify stress concentration effects induced by localized corrosion and to transform the fatigue strengths to a condition without corrosion‐induced notches or surface irregularities, thereby quantifying the pronounced influence of corrosion‐induced geometrical irregularities on the fatigue resistance of lean duplex stainless steel.