Application of bipolar electrochemistry to assess the ambient temperature corrosion resistance of solution annealed type 2205 duplex stainless steel

The corrosion resistance of solution annealing heat-treated type 2205 duplex stainless steel microstructures was assessed with a bipolar electrochemistry technique. Chemical element partitioning in both crystallographic phases was correlated to simulations of critical pitting temperatures. The as-received microstructure had the highest pit nucleation resistance, with high-temperature solution annealing treatment revealing reduced pit growth rates. Pit nucleation occurred either within the ferrite phase or at ferrite-austenite interfaces, with the resulting pit shape affected by the microstructure characteristics. The results of this study are discussed in the framework of microstructure design for enhanced corrosion resistance in duplex stainless steels. •Different solution annealing heat treatments have been applied to tailor microstructure characteristics of DSS 2205.•Standard electrochemical corrosion tests have been compared to novel bipolar electrochemistry assessments.•The room temperature pitting corrosion has been determined, with pit nucleation and growth characteristics.•The as received sample had the highest pit nucleation resistance, but not the lowest pit growth rates.•New insights for microstructure design to optimise corrosion resistance are discussed. [Display omitted]