Mechanistic Insights Into Atmospheric Corrosion Behaviour of Interstitial‐Free Steel Under Tropical Marine Climate of Mumbai

The formation of a protective rust layer on the surface of the steel slows down the corrosion process. In the present study, the atmospheric corrosion behaviour of the interstitial free (IF) steel coupons was investigated by exposing the coupons in the atmosphere of Mumbai for 1 year. The electrochemical properties of the rust layer were studied using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and Mott‐Schottky (MS) analyses. Grazing index X‐ray diffraction, scanning electron microscope and Raman spectroscopy determined the rust layer morphology and phases. The results depicted that the development of the rust layer is strongly dependent on the environmental parameters and pollutant levels in the atmosphere. High accumulated rainfall and high pollutant levels resulted in a nonprotective rust layer. The physical representation of the rust layer evolution in the atmosphere of Mumbai was elucidated based on the rust layer characterisations, EIS, and MS results.