Kinetics of Galvanostatic Chloride Pitting of Stainless Steels in Chloride Solutions

To check the theory, the corrosion of steels 12X18H10T and 10X17H13M2T is studied during galvanostatic polarization at different \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$C_{Cl^ - }$$ \end{document}, current densities, and temperatures. The morphology and size distribution of pits are discussed. In E vs. logτ curves are shown to demonstrate a single linear segment for steel 12X18H10T and two linear segments for 10X17H13M2T (as for pure Fe, according to the literature data [12]), namely, the initial segment with a steep slope and the later one with more gentle slope. The single slope ¦− ∂E/∂ log τ of steel 12X18H10T and the later (gentle) slope, which is observed for both steel 10X17H13M2T and Fe, correspond to those predicted in [3, 4, 7], while the earlier steep slope corresponds to crevice-type pitting.