Sodium silicate corrosion inhibition behaviour for carbon steel in a dynamic salt water environment

Abstract

This work investigates the sustainable green corrosion inhibitor sodium silicate (SS) in inhibition efficiency (IE) and mechanism for carbon steel in a dynamic 3 wt% NaCl environment. Electrochemical impedance spectroscopy and potentiodynamic scans are performed within a rotating cylinder electrode setup at variable conditions. Increasing SS dosage (≤10mM) under constant laminar flow results in higher IE (up to 99.8%), linked to replacement of water by silicate species, followed by more structured film formation at the steel surface. Increasing flow rate results in maximum IE at intermediate flow rate, linked to faster transport of silicate and cathodic species to the steel surface and more mechanical removal of the film.