Comparative statistical analysis of pitting in Two 2205 duplex stainless steel variants

The inherent variability of pitting poses challenges in accurately evaluating the pitting resistance due to potential disparities in test results. This study compares the pitting resistance of two commercial 2205 duplex stainless steels. Counterintuitively, the variant with higher Pitting Resistance Equivalent Number, exhibits a lower Critical Pitting Temperature. Through the potentiostatic pulse test and potentiostatic polarization, this variant is observed to have a greater number of pitting initiation sites. Further investigation, using SEM inclusion statistics, reveals an increased presence of inclusions rich in calcium oxides as the underlying cause of this unexpected phenomenon.