Online monitoring of crevice corrosion with electrochemical noise

The time-related cumulated noise charges extracted from the noise signals between two "identical" crevice electrodes yield a direct quantitative easy-to-interpret information on time-related corrosion intensities in the crevice. A new software-assisted method of noise data evaluation allows a "counting of coulombs" exchanged between the system electrodes, the results of which directly correlate with the metal dissolution intensity hi the crevice. The versatility of this "CoulCount" method is demonstrated in a failure analysis on the cause of crevice corrosion at spigots of automotive cooling water pumps.