Corrosion fatigue behaviour of HFMI-treated butt welds

•Investigating influence of corrosion on the efficiency of HFMI.•Application of laboratory tests to simulate real marine corrosion conditions.•Correlation between laboratory and real conditions based on a previous study.•Influence of loading mode taken into consideration.•Boundaries of the research set to tackle a practical problem of offshore engineering.•Significant increase of fatigue life in corrosive environment.•Present first-step investigation clarifies the next steps to be taken. The present study reports on the results of a completed research project, which investigated the corrosion fatigue behaviour of weldments made of structural steel S355J2+N treated with the High Frequency Mechanical Impact (HFMI). Main goal has been the estimation of short corrosion on the surface layer (