Kinetics of growth of semi-spheric pittings in the vicinity repassivation potential depending on bulk concentration of activator anions

A general case of semi-spheric pittings development in aqueous solutions of electrolyte of NaCl or LiCl type at different values of C0, usually studied in the range approximately equal to 10-5-10-3 g-ionxcm-3 (approximately equal to 10-2-100 g-ionxl-1), has been analyzed. On the basis of experimental data on participation of anion-activators and water molecules in the process of metal dissolution in pitting, and using the previously obtained equations, kinetics of open and closed semi-spheric pittings during galvanostatic anode polarization in neutral chloride solutions with different volumetric concentration of Cl--ions (C0) has been considered. In a general case the process kinetics is described by a complex equation, the boundary, more simple forms of which, correspond to the initial (A) and subsequent (B) stages of open pitting development, or to certain stable conditions of closed pitting development