The effects of cathodizing on the durability of an IrO2-based anode in an electrogalvanizing line (EGL) have been investigated. A comparison of the surface morphology of the anodes after electrolysis with anodic, cathodic, and periodically reversed currents indicated that the partial anomalous deterioration of the anode outside the strip width in EGL was caused by periodic cathodizing of the anode. The lifetime of the anode during the periodically reversed electrolysis significantly depends on the cathodic current density, the frequency of the current reversal, and the ratio of the cathodic period to the anodic period, tc/ta. The lifetime is shortened with an increase in the cathodic current density, frequency, and tc/ta. The consumption rate of the catalytic layer of the anode during the periodically reversed electrolysis was compared to that during cathodic current electrolysis. The results indicated that the periodic current reversal induced a significant increase in the consumption rate even at the same cathodic current density. The difference in the deterioration modes of the catalytic layers during the cathodic and periodically reversed electrolysis is also discussed.
