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The mechanisms of corrosion inhibition of AA2024-T3 by vanadates were studied in this work using the split cell technique and polarization curves. The electrochemical behavior of clear solutions containing metavanadates and orange solutions containing decavanadates was clearly distinctive. Injection of metavanadates to the cathode side of the different split cell setups greatly reduced the galvanic current, indicating a potent inhibition of the oxygen reduction kinetics. The galvanic current never exhibited a transient current peak, suggesting that metavanadates inhibit AA2024-T3 corrosion by a mechanism that does not involve electrochemical reduction. Injection of metavanadate to the anode side of the different split cells had no effect on the galvanic current. Injection of orange decavanadate to the cathode side of the AA2024-T3 split cell resulted in a large current peak, associated with the electrochemical reduction of decavanadate. However, decavanadates did not impart significant corrosion protection.

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Electrochemical voltage and current noise (EN) were measured simultaneously with acoustic emission (AE) during intergranular stress-corrosion cracking (IGSCC) on tensile specimens under a constant load. The elongation of the test specimens was also measured continuously during the tests, as an additional measuring technique. The test specimens were made from sensitized stainless steel of type 304, and immersed in an aqueous solution of sodium thiosulphate. The main aim of our work was to find out how successfully IGSCC processes could be detected by the simultaneous use of all three measurement methods. The results of the tests indicated that the accumulation of cracking and dissolution events could be satisfactorily monitored, whereas it was not possible to detect individual IGSCC events with the existing measuring set-up. It is not clear whether this inability to detect single IGSCC events was a consequence of the continuous nature of the IGSCC processes, or whether it was due to the insufficient resolution of the measurement system set-up.