THE INFLUENCE OF CHEMICAL COMPOSITION AND CURRENT DENSITY UPON THE SPECIFIC CONSUMPTION OF Fe-Si ANODES USED IN CATHODIC PROTECTION

摘要

In the paper the behaviour of some Fe-Si anodes containing 0.22-18.4% Si, which were exposed to a current density of 5-80 A/m~2 in Na_2SO_4 solution with a concentration of 25 g/L for 6 months was studied. The specific anodic consumption was evaluated gravimetrically and through the chemical analysis of the solution. For a usual current density of 20 A/m~2, the specific consumption of the anodes containing 14.4-18.4% Si was 0.15-0.25 kg/A year. The crust formed on the anodes allows the ionic transfer, while the anodic and cathodic potentials remained the same over the testing period.