Study on the galvanic corrosion of titanium and stainless steel couple with the synergistic effect of proton and fluoride ion

The galvanic corrosion of titanium/304 stainless steel (TA1/304SS) couple was investigated in neutral and acidic solution with and without fluorine ion (F-) using macro-electrochemical technique and scanning electrochemical microscope (SECM). The results show that the synergistic effect of H+ and F- affects the passive film on the surface of galvanic couple, resulting in a great change in heterogeneous reaction rate constant and surface electrochemical activity characterized by approach curve and surface mapping of SECM in feedback mode. In addition, a typical polarity reversal occurs in pH = 2.0 acidic solution with adding F- which the TA1 is anodic to 304SS.