Corrosion Behavior of Pre-oxidized GH4169 Alloy with Solid NaCl Deposited in a Wet Oxygen Flow at 600 °C

The corrosion behavior of the pre-oxidized GH4169 alloy was studied after 20 h of exposure under a solid NaCl deposit film in a wet O2 environment at 600 °C by mass-gain measurements, X-ray diffraction, scanning electron microscopy, transmission electron microscopy methods. The results indicate that the pre-oxidized GH4169 alloy undergoes serious corrosion in the corrosive condition. The preformed Cr2O3 layer is gradually destroyed by deposit NaCl, and the inner Nb2O5 layer beneath the complete outer Cr2O3 layer also reacts with NaCl to form NaNbO3. The electrochemical test results testified the existence of electrochemical reactions during this corrosion process. The corrosion behavior of pre-oxidized GH4169 under a solid NaCl deposit film in a wet O2 environment at 600 °C has been discussed in detail.