Materials Science Forum Vol. 1046

Abstract: Application of sustainable chemical compounds for corrosion protection of carbon steels employed in H₂O formed petrochemical drilling fluid environment (WPDF) is an effective alternative to toxic chemical compounds. The protection performance of calciofon (CF) and rosmarinus officinalis (RS) on low carbon steel (LST) in WPDF was studied with potentiodynamic polarization technique and optical microscopic characterization. Results output depict CF and RS performed adequately at specific inhibitor concentrations with average inhibition performance above 80% for CG and 90% for RS. CG exhibited mixed type inhibition effect compared to RS which exhibited anodic inhibition. The polarization curves obtained in the presence of both compounds showed they induce passivation of LST surface after anodic polarization before breakdown at the transpassive region from the lowest to highest concentration inhibitor concentrations due to their film forming and adsorption characteristics. This observation was corroborated from the protected steel surfaces which contrasts the non-protected control steel specimen which exhibited severe surface deterioration, corrosion pits and numerous furrows.

Abstract: Gravimetric and statistical analysis was utilized to assess the inhibition performance of extracts of green tea and moringa on 1070 aluminum in 0.5M H₂SO₄ solution. Data output showed green tea extract performed more effectively than moringa extract, and at all concentrations studied with optimal inhibition efficiency value of 95.08% compared to moringa which performed effectively at only one concentration with optimal value of 72.38%. Inhibition efficiency values for both extracts varied significantly with reference to exposure time and extract concentration. The optimal mean inhibition value for green tea and moringa extracts are 88.71% and 66.65%. However, the least standard deviation value of 6.22 was obtained for green tea extract with highest inhibition value indication stable inhibition and thermodynamic stability with reference to exposure time. Statistical data showed 90.5% of inhibition output for green tea extract and 9.52% of inhibition output for moringa extract were above 70% inhibition efficiency at margin of error of +12.6. Analysis of variance showed exposure time is the only statistically relevant variable influencing the inhibition output of green tea with statistical value of 78% while exposure time and moringa extract concentration are the both statistically relevant variables influencing the inhibition output of moringa with values of 61.02% and 24.02%.