INITIATION AND PROPAGATION OF PITTING OF 16Mn CARBON STEEL IN CHLORIDE SOLUTIONS STUDIED BY ELECTROCHEMICAL NOISE ANALYSIS

摘要

The passivity and pitting initiation behaviour of 16Mn carbon steel in different concentration of NaCl+0.5mol/L NaHCO3 solution were studied by statistical electrochemical noise analysis. It was found that the initiation rate (λ) of metastable pits, generally defined by the ratio of the number of typical current transients during a certain period, can be described by the equation: λ(t) =λmax(1-exp(-at)),0