Electrochemical evaluation of the corrosion inhibition effect of calcium gluconate on mild steel in water based petrochemical drilling fluid

Abstract

Application of biodegradable organic derivatives for corrosion inhibition of metallic alloys in water based petrochemical drilling fluid solution (WPDF) serves as a sustainable alternative to toxic chemical inhibiting compounds. The electrochemical corrosion inhibition of calcium gluconate (CG), on mild steel in WPDF was evaluated with potentiodynamic polarization and optical microscopy analysis. Statistical analysis on the effect of CG concentration on its inhibition performance was done through One Way ANOVA. Results show CG performed effectively at all concentration studied with average inhibition efficiency above 85%. CG exhibited mixed type inhibition property. The polarization plots obtained showed CG induces passivation of MS from the lowest to highest concentration due to its film forming and adsorption characteristics. This observation was further confirmed from the steel morphologies where the inhibited steel was relatively smooth while the non-inhibited morphology was badly corroded with visible corrosion pits.