Efficiency of organic compounds as VCIs for the packaging of carbon steel engine elements in automotive

Carbon steel elements for motor engine assembly are produced in different companies typically settled far from the assembly plant. As corrosion must be avoided, condition of transportation are of paramount importance. VCIs are used in the packaging, applied of the polymer sheet used to envelop the metallic element of impregnated in the carbon box. In the present paper, the inhibition efficiency of several pure organic substances was studied by potentiodynamic measurements and linear polarization resistance (LPR) tests. Organic substances containing a carboxylic group and/or an aminic group were tested and the results were comparted with three commercial VCIs. Caprylic acid showed the best behavior, while maleic acid proved the highest corrosion rate; benzoic and tartaric acids showed good inhibition effect.