Evaluation of the effectiveness of molybdate-based coating on reinforcing steel during the pre-construction phase of offshore projects
Tóm tắt
The corrosion behavior of carbon steel in 3.5 wt.% NaCl solution and the inhibition performance of ammonium heptamolybdate (AHM)/sodium carbonate (Na₂CO₃) were investigated using electrochemical techniques (Tafel, EIS), gravimetric measurements, and SEM/EDS analyses. The unprotected steel showed rapid corrosion, as indicated by high Icorr, low Rcorr, and severe surface damage. The addition of AHM/Na₂CO₃ significantly reduced corrosion, with the In3 system (1.5 g/L AHM + 1.5 g/L Na₂CO₃) exhibited the best performance In3 achieved the lowest Icorr, the highest resistance, and an inhibition efficiency above 95%. Gravimetric measurements confirmed long-term stability, while SEM/EDS revealed a compact and adherent protective film that effectively blocked chloride penetration. These results highlight In3 as an highly effective and sustainable corrosion inhibitor for carbon steel in chloride environments, suitable for protecting steel during transportation to offshore construction sites.
