This paper sets out to evaluate the corrosion of ASTM A131 grade A36 carbon steel exposed to a diesel oil S10 / saline water system and the biodegradation of diesel oil S10 to simulate storage, transport and fuel use systems during a period of 30 days. The corrosion process was investigated through electrochemical tests of Open Circuit Potential (OCP), Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization (LP). The morphology of the corrosion products were analyzed by Scanning Electron Microscopy (SEM). The results showed that the presence of saline water in the system containing diesel oil is an aggravating factor which promotes the biodegradation of the fuel and, consequently, aggravates the corrosion process.

This paper sets out to evaluate the corrosion and biocorrosion of carbon steel ASTM A283 exposed to a Diesel S10 oil/tap water system under static conditions for 90 days. The following analyzes were performed: physico-chemical in tap water, sulfur content in Diesel S10 and quantification of sessile microorganisms in the biofilm formed on the metal. To monitor the corrosion process, mass loss, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), confocal laser microscopy and X-ray diffraction (XRD) were performed. There were changes in the composition of the medium, correlated with the formation of corrosion and biofilm products. There was biodegradation of the fuel, which in contact with water influenced the development of microorganisms. Moreover, the corrosion rate was classified as moderate, the main form of corrosion being seen to be local alveolar corrosion. Therefore, the results revealed that water in diesel oil can be an aggravating factor in the process of corrosion and biocorrosion.