The phenomenon of pitting in carbon steel exposed to alkaline solutions of nitrate and chloride was studied with the cyclic potentiodynamic polarization technique. Open-circuit and pitting potentials were measured on specimens of ASTM A537 carbon steel in pH 9.73 salt solutions at 40°C, with and without the inhibiting nitrite ion present. Nitrate is not so aggressive a pitting agent as is chloride. Both nitrate and chloride did induce passivity breakdown and pitting in nitrite-free solutions, but the carbon steel retained passivity in solutions with 0.11-M nitrite even at a nitrate concentration of 2.2 M.

Subject
Radioactive waste, Nitrites, Repassivation potentials, Chloride solutions, Constants, Ion concentrations, Nitrates, Electric potential, Pitting, Carbon steel, Chlorides, Electrochemical potential, Wastes
Keywords:
Localized corrosion, cyclic potentiodynamic polarization, passivity, chloride
Government work published by the Association for Materials Protection and Performance (AMPP) with permission of the author(s). Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
1999
GOV
You do not currently have access to this content.