Corrosion of Galvanized and Galvannealed Steel in Solutions of pH 9.0 to 14.0^★ Available to Purchase

Well-characterized zinc coatings on steel have been prepared so that either the eta or zeta phase was present as the outermost layer. Their electrochemical behavior was studied in a range of solutions by galvanostatic anodic polarization and potentiodynamic anodic polarization scans. The corrosion products were identified using scanning electron microscopy (SEM) and x-ray analysis. Results show that the solution pH has the most marked effect on electrochemical behavior and the nature of the corrosion product formed. At a given solution pH, the behavior and products formed are modified according to the concentration of chloride in the solution and the type of iron-zinc alloy layer investigated. The results are discussed in relation to the practical use of galvanized reinforcement in concrete.