fig5

Figure 5. Study of the passive film degradation of duplex stainless steel after anodic polarization at 900 and 1400 mV (vs. Ag/AgCl) in 1 M NaCl (aq). (A) During the polarization test, selective dissolution occurred on the ferrite phase and the austenite phase was corroded as well. (Reproduced with permission^[43]. Copyright 2018, Elsevier). (B) The main composition was ferrite and austenite.(Reproduced with permission^[43]. Copyright 2018, Elsevier). (C) The small diffraction peaks corresponded to multiple crystal oxides (Reproduced with permission^[43]. Copyright 2018, Elsevier). (D) Chromium oxide is the major compound of crystal oxides. The random noise represents the nano-crystalline structure of the oxides. (Reproduced with permission^[43]. Copyright 2018, Elsevier). (E and F) The X-Ray Fluorescence (XRF) data for Fe, Cr, Ni, and Mo after applying different anodic polarization at room temperature^[44]. (Open access). (G) The degradation mechanism of 2,507 duplex stainless steel under the applied potential^[44]. (Open access).