Electrochemical noise analysis on the pit corrosion susceptibility of Mg–10Gd–2Y–0.5Zr, AZ91D alloy and pure magnesium using stochastic model

Pit corrosion susceptibilities of Mg–10Gd–2Y–0.5Zr alloy, AZ91D alloy and pure magnesium were investigated by means of electrochemical noise (EN). The EN data have been analyzed based upon the combined stochastic theory and shot-noise theory. Pit initiation process has been modeled as a nonhomogeneous Poisson process and analyzed using a Weibull distribution function. Pit growth process has been simulated by a nonhomogeneous Markov process and analyzed using Gumbel distribution function. The EN results implied that Mg–10Gd–2Y–0.5Zr alloy had the highest pit initiation rate and pit growth probability, which revealed that Mg–10Gd–2Y–0.5Zr alloy had the highest pit susceptibility.