Methods for making alloy 600 resistant to sensitization and intergranular corrosion

Abstract

Thermomechanical processing (TMP) and strain annealing were performed on alloy 600. The degree of sensitization (DOS) and susceptibility to intergranular corrosion (IGC) were assessed by electrochemical potentiokinetic reactivation and weight loss tests respectively. The grain boundary character distribution was established by orientation imaging microscopy. It was shown that as the fraction of special boundaries increased with TMP/strain annealing, the DOS and IGC rates decreased drastically. Alloy 600 with fraction of special boundaries above 85% showed only uniform corrosion. The DOS and IGC values indicating resistance to sensitization and IGC and the methods to achieve such values have been highlighted. © 2013 Elsevier Ltd.