Effect of Cr and Ti additions on the corrosion behavior of Fe3Al alloys in chloride-containing sulfuric acid solutions

The corrosion behavior of Fe3Al, Fe3Al–2Ti, Fe3Al–2Cr, and Fe3Al–5Cr in 0.1 N H2SO4 and chloride-containing 0.1 N H2SO4 solutions is reported in this paper. The corrosion resistance has been evaluated by potentiodynamic polarization measurements. The results show that Fe3Al alloy in H2SO4 has a wide passivation region with low passivation current, but their passive films are susceptible to damage in chloride-containing H2SO4. The passivation behavior of Fe3Al alloys can be improved by Cr and Ti additions in H2SO4 or chloride-containing H2SO4. The critical concentration of NaCl in 0.1 N H2SO4 to damage the passive film of Fe3Al-based alloys is approximately 10− 2∼10− 1 g/l, depending on the additions of alloying elements.