Influences of Mn in solid solution on the pitting corrosion behaviour of Fe-23 wt%Cr-based alloys

The effects of Mn in solid solution on localised corrosion behaviour were investigated using Fe–23 wt% Cr-based alloys containing 0.04-8.01 wt% Mn without Mn-related inclusions. It was revealed that the Mn in solid solution decreased the passive film resistance via incorporation into the passive film, which resulted in lowering the pitting potential value. In addition, it was found that the alloying Mn lowered the repassivation potential, because the Mn in solid solution increased the matrix dissolution rate inside the pit cavity.