Corrosion inhibation of sodium benzoate on zinc alloys in seawater and acidic solutions

Abstract

Electrochemical properties and corrosion inhibition of sodium benzoate on Zinc alloys were studied in seawater and acidic solutions at room temperature. Weight loss and electrochemical properties of zinc alloys as well as adsorption and their surface morphology in the presence of sodium benzoate were investigated. Weight loss experiment involving immersion of alloys in seawater and in acidic solutions was conducted for 30days on all the samples. The effects of dissolved oxygen in environmental air circulation on the alloys in seawater were also investigated. The corrosion products and the microstructure on the Zinc alloys were characterized using Scanning Electron Microscope (SEM). Results obtained in this study indicated that weight loss and electrochemical measurement for zinc alloys in seawater and acidic solutions after varied immersion period showed that in the presence of sodium benzoate, the corrosion current densities and corrosion rates of the alloys were significantly decreased and at the same time the inhibition efficiency, IE (%) were increased. The results also revealed that the weight losses of the alloys in sulphuric acid were higher compared to that of in the acetic acid. The presence of more dissolved oxygen in air circulation in the environment contributed to the dissolution of Zinc alloys. Corrosion rate is being calculated from the data and the results collected from the immersed Zinc alloys samples' weight loss in the acidic solutions and seawater. The results from SEM study elucidated that in the presence of sodium benzoate, after immersion in seawater, a thin film was formed on the specimen surface.