Potentiostatic Polarisation Responses Of Mild Steel In Seawater And Acid Environments

ABSTRACT The imperative of secondary corrosion response evaluation in real-time to prevent catastrophic failure in service continues to be at forefront of research efforts. In this paper electrochemical polarisation response of mild steel in acid and seawater media was studied. Specially prepared mild steel plate coupons were immersed in seawater and 1M hydrochloric acid respectively at a scan rate of 0.2 volts per second while the corrosion potentials varied from -0.6 volts to 1.6 volts. The electrode polarisation response data obtained is used to analyse the material relevant electrochemical parameters. The results demonstrate the well established corrosion phenomenon of carbon steel mild steel occasioned by chloride ions aggressiveness coupled with the acidic nature of the corrosion product. Thus the continuous corrosion without any passive time-lag of the mild steel in seawater is predicated on the large concentration of chloride ions. It is concluded that corrosion mitigation of mild steel in seawater and hydrochloric acid entails either an entire prevention of accumulation of corrosion product or an efficient neutralisation of its acidic nature.