Long‐Term Marine Atmospheric Exposure of a Carbon Steel From the ‘Lighthouse at the End of the World’: Corrosion and Microstructural Characterization

ABSTRACT This study presents the corrosion and microstructural characterization of a carbon steel component exposed to a marine atmosphere for over one hundred years. The sample was retrieved from the historical ‘Lighthouse at the End of the World’ located on Isla de los Estados, Argentina—a site subject to harsh oceanic conditions and continuous salt‐laden winds. A detailed analysis of corrosion products was carried out using X‐ray diffraction (XRD), transmission Mössbauer spectroscopy (TMS), Raman spectroscopy (RS) and scanning electron microscopy (SEM/EDS), revealing a multilayered structure of iron oxides and oxyhydroxides. Electrochemical measurements, including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), were performed to assess the residual corrosion behaviour of the aged material. The results provide valuable insights into the long‐term degradation mechanisms of carbon steels in aggressive marine environments and stand for a rare case study of natural atmospheric corrosion over a century‐long timescale.