Aspartic acid as a corrosion inhibitor for carbon steel

Abstract

Carbon steel is one of the most used metal alloys in industrial applications due to its low cost when compared to other metallic materials. However, its use may be limited due to its tendency to corrode. Thus, it is necessary to develop methods that inhibit its degradation. One way to reduce corrosion is through the use of corrosion inhibitors, which are generally organic compounds and can act by adsorption to form protective films. Some organic compounds with heteroatoms such as O, N, S inhibit corrosion by forming a protective film. However, the use of some inhibitors has been limited due to their harmful effect on the environment. For this reason, research has been developed seeking ecologically correct corrosion inhibitors. This work aims to evaluate the inhibitory effect of aspartic acid against the corrosion of carbon steel in different electrolytic media. In the present work, aspartic acid (AA) was used as a corrosion inhibitor in carbon steel. (AA) solutions at concentrations of 10-2, 10-3, 10-4, 10-5 and 10-6 mol L-1 were used as corrosion inhibitors. Diluted solutions of H2SO4 under conditions of pH 1.5; 2.1; 2.97 and 4.0 were used as a corrosive agent. The mass loss tests were performed by immersion of carbon steel samples in H2SO4 solutions for a period of 168 hours, the mass variation was determined by weighing the samples before and after the immersion time. Additionally, with the mass loss tests, the inhibition efficiency promoted by the inhibitor solutions will be determined. The form of corrosion of carbon steel was determined by evaluating the surface morphology using light microscopy. The inhibition mechanism promoted by aspartic acid was determined by open circuit potential (PCA) assays.