Experimental and theoretical studies of hydralazine hydrochloride as corrosion inhibitor for mild steel in HCl acid medium
Abstract
Purpose
The purpose of this paper is to investigate the inhibition effect of hydralazine hydrochloride as a corrosion inhibitor for mild steel in 1M HCl. The inhibition effect was studied at different temperatures, ranging from 303 to 333°K.
Design/methodology/approach
The inhibition efficiency of hydralazine hydrochloride was analyzed using weight loss, Tafel polarization, electrochemical impedance spectroscopy and surface morphology methods. The effect of temperature on the corrosion behavior of mild steel in 1M HCl was studied and discussed using an adsorption isotherm and activation parameters.
Findings
Weight loss, polarization and impedance showed that the inhibition efficiency increases with an increase in the concentration of hydralazine hydrochloride for mild steel in 1M HCl. The inhibitive action may be attributed to the adsorption of the inhibitor molecule on the active sites of the metal surface by the Langmuir adsorption isotherm. Polarization curves indicated that hydralazine hydrochloride acts as a mixed-type inhibitor. Scanning electron microscopy was performed on inhibited and uninhibited mild steel samples to characterize the surface. Thermodynamic parameter indicated that the adsorption of hydralazine hydrochloride is a spontaneous process and the adsorption occurs chemically.
Originality/value
The inhibition effect of hydralazine hydrochloride for mild steel has been investigated at different temperatures, ranging from 303 to 333°K. Hydralazine hydrochloride was a good inhibitor at a higher temperature.
Keywords
Acknowledgements
The authors are obliged to the authorities of Srinivas School of Engineering, Mukka, Mangalore, Karnataka, India for providing excellent laboratory facilities. The authors also express thanks to Department of Science and Technology, New Delhi, Govt. of India under the fast track scheme for young scientist [DST: Project Sanction No. SR/FT/CS-147 2011dated 13-07-2012] and All India Council for Technical Education, New Delhi, Govt. of India under MODROBS scheme [Ref. No 8,024/RIFD/MOD 292 /2010-11 dated 31-03-2011] for providing instrumental amenities.
Citation
Prasanna, B.M., Praveen, B.M., Hebbar, N. and Venkatesha, T.V. (2015), "Experimental and theoretical studies of hydralazine hydrochloride as corrosion inhibitor for mild steel in HCl acid medium", Anti-Corrosion Methods and Materials, Vol. 63 No. 1, pp. 47-55. https://doi.org/10.1108/ACMM-05-2014-1388
Publisher
:Emerald Group Publishing Limited
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