Abstract: The inhibition of mild steel varying concentration of ammonium molybdate tetrahydrate (AMT) in 1M HCl has been studied using linear potentiodynamic polarization (LPP) techniques. SEM was used to examine the morphology of the samples, while the microhardness of the test samples were investigated using the Vickers hardness testing techniques. The outcome of the linear polarization test unveils decrease in the rate of corrosion with the increase in the mass concentration of ammonium molybdate tetrahydrate in the corrosive environment. The inhibited samples were found to exhibit reduced current density and higher value of polarization resistance compared to the uninhibited sample. The SEM micrograph shows that the inhibited samples exhibits better morphology compared to the bared sample with notable thin inhibitory layer. The examination of the microhardness of the samples shows that the inhibited samples displayed improved percentage in microhardness relative to the uninhibited sample, ranging from 3.69 % to 7.86 %. Maximum inhibitory efficiency of 67.53 % was recorded for the 1.5 g AMT inhibited sample. More, so Polarization curve indicates that in AMT acted as a mixed-type inhibitor at room temperature. Adsorption of AMT particles on mild steel was found to have agreed with Freundlich isotherm law with correlation regression coefficient of R2= 0.9718.
Authors: O.S.I. Fayomi, A.P.I Popoola, and I.G.Akande
Keywords: Inhibitor; Isotherm; Morphology; Corrosion and adsorption