Molybdate-phosphate conversion coatings to protect steel in a simulated concrete pore solution

摘要

For the corrosion protection of steel rebars in concrete, five different molybdate-phosphate conversion coatings were prepared, by changing the molybdate-phosphate ratio in the conversion baths. Their composition and morphology were studied with GD-OES, XPS, Raman spectroscopy and SEM-EDX and a schematic representation of their structure is suggested. Further, the corrosion resistance properties of the coatings were evaluated in a simulated concrete pore solution (CPS) containing chlorides, using anodic polarization measurements. Thanks to the elaborated surface analysis their corrosion behaviour could be correlated to their structure.