The effect of microstructure and elemental content on corrosion and corrosion inhibition of mild steel in a 0.5 M H2SO4 environment

Abstract

The influence of composition and surface microstructure on the corrosion behavior of low carbon steel specimens from Nigeria (NCS) and China (CCS) in a 0.5 M H₂SO₄ environment has been investigated using electrochemical techniques and surface probe techniques. The corrosion inhibition performance of Chrysophyllum albidum extract (CA) and synergistic iodide additives (KI) were assessed as well. The obtained results reveal that NCS was more susceptible to corrosion in uninhibited 0.5 M H₂SO₄ solution than CCS, which presented a more positive surface charge. CA inhibited the corrosion of both specimens, yielding maximum inhibition efficiencies of 89.6% and 48.5% for NCS and CCS, respectively, which were further increased to 93.9% and 98.9% on introduction of iodide ions. The corrosion and corrosion inhibition behavior of the carbon steel specimens were influenced by the metal composition and microstructure.