Abstract

The performance of different sizes of zinc, and aluminium galvanic anodes on the cathodic protection of mild steel in seawater and 0.2 M sulphuric acid was evaluated at ambient temperature. The magnitude of corrosion protection by the galvanic anodes was observed by weight loss method, corrosion rate calculation and potential measurement technique. It was observed that the aluminium anodes proved more effective as sacrificial anode for mild steel in seawater environment. In sulphuric acid environment, the zinc anode gave a more protective performance than aluminium anode. Potential measurement results obtained were found to correspond with the results obtained from weight loss method. For both environments, the effects of a varying cross-sectional area and the anode material on the cathodic protection of mild steel were examined.

Key words: Cathodic protection, corrosion, galvanic, impressed current, anodes, seawater, sulphuric acid, weight loss, corrosion rate, potential measurements, zinc, aluminium.