EFFECT OF HYDROGEN ON CATHODIC CORROSION OF TITANIUM ALUMINIDE

Cathodic corrosion of titanium aluminide (TiAl) during hydrogen chargi ng in various acidic aqueous solutions and in molten salt at 160 degre es C was studied. At constant potential, the rate of cathodic corrosio n (V) was much higher than during anodic dissolution, and V increased linearly with increasing current. V was 10 times higher in the acid so lution than in the salt solution under the same current. Disruption of the surface film by local hydride formation during cathodic polarizat ion was shown to be the key step.