Paper Title
Corrosion Study of Mild Steel using Dithizone as Corrosion Inhibitor in Hcl Solution at 50oc

Abstract
Mechanical, electrical and adsorption studies of mild steel in 1.0 M HCl solution with dithizone as corrosion inhibitor were performed by using gravimetric analysis, adsorption isotherm analysis, resistance gradient analysis and analysis of different elastic constants like Young�s modulus (Y), Bulk modulus (K) , Shear modulus (η) and Poisson�s ratio (σ). It is found that dithizone shows very good corrosion inhibition action (Percentage corrosion inhibition efficiency more than 90%) at 50oC temperature in HCl solution by its basic nature and adsorption action on mild steel surface due to presence of many lone pair sites and unsaturated π delocalized system in its structure. Electrical analysis reveals that the rate of increase of resistance gradient due to corrosion action of mild steel decreases significantly with the increased concentrations of inhibitor which support the retardation of loss in mechanical strength and surface erosion due to inhibition action of dithizone. Increased value of Poisson�s ratio suggests the reduction in longitudinal strain which checks the loss of hardness and strength of mild steel by action of strong acidic environment. Type of adsorption (Langmuir Adsorption isotherm) and probable mechanism of the inhibition action of dithizone are also reported in this study. Key Words: Dithizone, Elastic constants, Langmuir adsorption isotherm, Poisson�s ratio, Resistance gradient, Corrosion inhibitor.