Insight into electrochemical passivation behavior and surface chemistry of 2205 duplex stainless steel: effect of tensile elastic stress

The effect of tensile elastic stress on passivation behavior and surface chemistry of 2205 duplex stainless steel is investigated. Elastic stress increases the potential drop at the film/solution interface, donor density and defects diffusion coefficient, resulting in the increase of passive current density. High elastic stress (≥60%σs) leads to the generation of soluble CrO3, the increase of oxidized Cr and Fe(Ⅱ) content and the decrease of film thickness, resulting in the quasi-steady-state current density no longer independent of potential. Passive film become denser from spontaneous passivation to primary passivation and Fe(III) compounds dominate the passive film under secondary passivation. •Passivation of 2205 DSS under elastic stress is studied.•Elastic stress results in the increase of Iss by decreasing d and increasing φf/s, ND, and D0.•High elastic stress (≥60% σs) leads to further increase of Iss, which is no longer independent of potential.•Elastic stress facilitates the increase of oxidized Cr and Fe(Ⅱ) content.•Potential makes passive film become denser until transpassivation occurs.