TITLE:
Investigate the Corrosion Inhibition of Mild Steel in Sulfuric Acid Solution by Thiosemicarbazide
AUTHORS:
Fatma Mohamed Mahgoub, S. M. Al-Rashdi
KEYWORDS:
Acidic Medium, Adsorption, Inhibitor Mild Steel and SEM
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.6 No.3,
July
20,
2016
ABSTRACT: Corrosion inhibition
of mild steel in 0.5 mol/L H2SO4 was investigated in the absence
and presence of different concentrations of thiosemicarbazide. The inhibition efficiency
of thiosemicarbazide was studied by electrochemical impedance methods, potentiodynamic
polarization and scanning electron microscopy at different inhibitor concentrations.
Inhibition efficiency, corrosion rate and surface coverage were evaluated at different
concentrations of thiosemicarbazide. Electrochemical impedance plots indicated that
the presence of the inhibitors increased the charge transfer resistance of the corrosion
process, increasing the inhibition efficiency. Polarization curves showed that
this compound acted as mixed type inhibitor. The results of the investigation
showed that this compound had good inhibiting properties for mild steel corrosion
in 0.5 M sulfuric acid. The adsorption isotherm studies showed that
Thiosemicarbazide adsorbed chemisorbed and formed a stable surface complex on
the mild steel surface. And Langmuir obeyed the adsorption isotherm. Scanning
electron microscopy analysis shows that, the surface morphology of the polished
mild steel in the presence of thiosemicarbazide as inhibitor is smoother surface
as compared with polished mild steel specimen in the absence of inhibitor.