Passivation and Corrosion Behavior of TF400 in Simulated Concrete Pore Solution

Abstract

In simulated concrete pore solution,passivation and corrosion behavior of TF400 titanium alloy (TF) and Common steel (CS) were investigated, with testing methods of electrochemical techniques and micro morphology. The results show that both TF and common steel bar can form adherent, compact and protective passive film on surface, improving the corrosion resistance. The polarization resistance (Rp) of titanium alloy is 10⁶ Ω.cm² which is three orders of magnitude of that of common steel bar (10³ Ω·cm²). When in a completely passivated state, the passive film resistance (Rf) of TF is 2 ×10⁵ Ω.cm², and that of CS is 2 ×10⁴ Ω.cm². TF400 titanium alloy exhibit superior corrosion resistance when exposed to high concentration of chlorine. The corrosion current density (Icorr) of TF is basically stable at 10⁻⁷ A/cm² and the Rp maintained at 10⁶ Ω.cm². As comparison, the Icorr of CS is 10⁻⁴ A/cm² and the Rp is 10³ Ω·cm².Whether the passivation performance or corrosion resistance, TF is far superior to CS, and can replace CS in marine concrete structures.