Effect of Inhibitor Concentration and Immersion Time on the Corrosion Rate and Inhibition Efficiency of AISI 1019 Steel in Inhibited Seawater Environment

Abstract

The effect of inhibitor concentration and immersion time on the corrosion rate and inhibition efficiency of AISI 1019 steel in seawater environment were investigated by means of weight loss measurement (WLM) at an interval of 6days for a period of 60 days. AISI 1019 steel were immersed in seawater solution in the absence and presence of varying inhibitor concentrations of potassium chromate (PC), Sodium Nitrite (SN), Methyl Orange (MO), Methyl Red (MR), Terminalia Catappa Leaves (TCL) Extract, Carica papaya Leaves (CPL) Extract. The results showed that there is an increase in inhibition efficiency with increase in inhibitor concentration and decrease in inhibition efficiency with increase in immersion time. The inorganic inhibitor (potassium chromate), inorganic inhibitor (Sodium Nitrite), the organic Inhibitor (Methyl Orange), the organic inhibitor (Methyl Red), the green inhibitor (Terminalia Catappa Leaves) and green inhibitor (Carica Papaya Leaves) produced their best inhibition efficiency of 71.94%, 634%, 68.94%, 68.32%, 62.7%, 59.79% respectively at a concentration of 10g/L. From the result obtained, the potassium chromate inhibitor has better inhibitory property than other inhibitors, which revealed that it is best suited for inhibition of corrosion of mild steel in seawater environment. Keywords: