An induced corrosion inhibition of X80 steel by using marine bacterium Marinobacter salsuginis

The corrosion behaviour of X80 pipeline steel was studied in a simulated marine environment inoculated with marine bacterium Marinobacter salsuginis. The electrochemical results showed that the increase in linear polarization resistance, charge transfer resistance, and the decrease in corrosion current density of the X80 pipeline steel immersed in the biotic medium indicated its high corrosion resistance compared to those in the abiotic medium. Surface morphological techniques including scanning electron microscopy, confocal laser scanning microscopy and live/dead cells staining were employed to observe the biofilm morphology and bacterial viability after different immersion times. X-ray photoelectron spectroscopy was used to analyse the oxides film formed on the steel surface. The obtained results indicated that the corrosion inhibition efficiency was obviously higher in the biotic medium compared to that in the abiotic medium. The high corrosion resistance of X80 steel in biotic medium was attributed to the formation of biofilm and the development of extracellular polymeric substances (EPS) layer on its surface.