Grain boundary nature and localized corrosion in 304 austenitic stainless steel

The present study had one broad objective - to systematically characterize effects of overall grain boundary nature on localized corrosion, intergranular corrosion (IGC) and stress corrosion cracking (IGSCC), of type 304 (UNS S 30400) austenitic stainless steel. Various combinations of cold rolling and solution annealing, were applied to alter relative the relative concentrations of 'special' or low CSL boundaries and to relate them with the local corrosion resistance, IGC and IGSCC, after respective sensitization treatments. It has been shown that both extreme high and low concentration of random (or high energy) boundaries can provide an effective means of control for localized corrosion, degree of sensitization (DOS), IGC and IGSCC, - the improvement in localized corrosion resistance at extreme grain boundary randomization being more effective.