Natural gums as green corrosion inhibitors for mild steel

Abstract

In this study the corrosion inhibition efficiency of Guar gum and Arabic gum are investigated on mild steel in concentrated chlorohydric acid. Weight loss and electrochemical methods, potentiondynamic polarization and electrochemical impedance spectroscopy were used to determine the optimum concentration of each gum. The results show that there is a direct correlation between concentration of inhibitor and corrosion inhibition efficiency, therefore the best efficiency was obtained at the highest concentration, 3.3 g/l. When comparing the two polysaccharides Guar gums has a better inhibition effect than Arabic gum at the same concentration. The inhibition mechanism was analysed by fitting the electrochemical results to an adsorption isotherm. This research offers a green alternative to the synthetic inhibitors used in today’s industry during acid pickling in the manufacturing process of mild steel. Both substances are naturally obtained and considered green corrosion inhibitors due to their negligible impact on the environment. Future research on the topic will include more natural compounds tests in the same experimental conditions and comparing them to market inhibitors in terms of efficiency.