Abstract
Applications of harmless fluid derivative for the sustenance of carbon steel in corrosive environments are more appropriate for environmental sustainability and safety of personnel. Admixture of grapefruit and lemongrass distillates was assessed for their protective performance on plain carbon steel within 0.5 M of H2SO4 and HCl solution through weight loss analysis and optical macroscopy studies. Results shows the plant extracts effectively stifled corrosion in both acids with inhibition value range (lowest to highest) of 98.65%-99.5% in H2SO4 solution and 96.31%- 98.39% in HCl. PCS in H2SO4 and HCl electrolyte at 0% extract concentrate were 5.330 mm/y and 2.701 mm/y. Inclusion of the distillate to the electrolyte significantly reduced the corrosion rates in both acids to midpoint values of 0.0448 mm/y and 0.072 mm/y at 240 h of test. The oil extract strongly adsorbed unto the steel surface by means of chemisorption with midpoint Gibbs free energy value above -44 Kjmol-1 signifying strong covalent bonding. The extract adsorption aligned with Langmuir and Frumkin adsorption isotherms with interaction coefficient above 0.9. Optical images of steel surface without inhibitor showed a severely corroded morphology and significant reduction in thickness. The protected steel substantially differs the earlier observation due to the presence of the oil extract which passivated the steel exterior.
Publisher
Trans Tech Publications, Ltd.
Subject
Condensed Matter Physics,General Materials Science,Atomic and Molecular Physics, and Optics
Reference25 articles.
1. R.T. Loto and P. Babalola: Corrosion polarization behavior and microstructural analysis of AA1070 aluminium silicon carbide matrix composites in acid chloride concentrations Cogent Eng. Vol. 4(1) (2017), p.1422229. http://doi.org/10.1080/23311916.2017.1422229.
2. J. Kruger and S. Begum: Corrosion of Metals: Overview, Reference Module in Materials Science and Materials Engineering (Elsevier, Amsterdam 2016).
3. B.S. Syrett: Cost of Corrosion in the Electric Power Industry EPRI Report 1004662 (2002).
4. G.H. Koch, M.P.H. Brongers, N.G. Thompson, Y. Paul Virmani and J.H. Payer: Corrosion Costs and Preventive Strategies in the United States Mats. Perform. (2002), pp.4-9.
5. G.H. Koch: Cost of corrosion, Trends in Oil and Gas Corrosion Research and Technologies, Production and Transmission (Elsevier, Amsterdam 2017) Chapter 1, pp.3-30.