Modeling the Dynamics of the Local Chromium-Nickel Steel Dissolution Process

Abstract

Abstract Analytical and simulation models of pitting corrosion on chromium-nickel steels under galvanostatic and potentiostatic polarization conditions are proposed. Under conditions of galvanostatic polarization three modes of local metal dissolution have been found. The labeled state graph which shows the transitions of a system from one dissolution mode to another has been offered. The values of stable pit formation time have been calculated. The additional model parameter «fraction of the pits being passivated» applied to establish the correlation between pit initiation and pit passivation rates in a stochastic model is proposed. It explains the variable dependence of a polarization potential on a pit repassivation rate.