In this study a novel characterization and an evaluation of the metastable pitting is introduced. The lifetime of the pits is described as a time period during which the alloy is dissolved. It was proved by theoretical calculation that the lifetime of pits could be unambiguously determined from a very important stochastical characteristic of the system, from the autocorrelation. The power spectrum density (PSD) of the process was also calculated and the effect of the event density, the propagation kinetic and the lifetime on the PSD was analyzed. The influence of the potential on the metastable pitting was investigated, and it was shown that mainly the lifetime of the pits increases with increasing potential.