Sanatkumar, B.S.Nayak, J.Nityananda Shetty, A.N.2026-02-052012International Journal of Hydrogen Energy, 2012, 37, 11, pp. 9431-94423603199https://doi.org/10.1016/j.ijhydene.2012.02.165https://idr.nitk.ac.in/handle/123456789/27006Electrochemical corrosion behavior and hydrogen evolution reaction of weld aged maraging steel have been investigated, in 1.0 M sulfuric acid solution containing different concentrations of 2-(4-chlorophenyl)-2-oxoethyl benzoate (CPOB). The data obtained from polarization technique showed that the corrosion current density (i <inf>corr</inf>) and the hydrogen evolution rate decrease, indicating a decrease in the corrosion rate of weld aged maraging steel as well as an increase in the inhibition efficiency (?%) with the increase in inhibitor concentration. Changes in impedance parameters were indicative of adsorption of CPOB on the metal surface, leading to the formation of protective film. Both activation (E <inf>a</inf>) and thermodynamic parameters (?G <inf>ads</inf> 0, ?H <inf>ads</inf> 0 and ?S <inf>ads</inf> 0) were calculated and discussed. The adsorption of CPOB on the weld aged maraging steel surface obeyed the Langmuir adsorption isotherm model. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) study confirmed the formation of an adsorbed protective film on the metal surface. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Corrosion current densitiesCorrosion inhibitionElectrochemical corrosion behaviorEnergy dispersive X ray spectroscopyHydrogen evolutionHydrogen evolution rateHydrogen evolution reactionsImpedance parametersInhibition efficiencyInhibitor concentrationLangmuir adsorption isothermsMetal surfacesOrganic inhibitorsPolarization techniquesSulfuric acid mediumSulfuric acid solutionThermodynamic parameterAdsorptionElectric impedanceElectrochemical corrosionHydrogenPolarizationScanning electron microscopySulfuric acidWeldingWeldsX ray spectroscopyMaraging steel