Corrosion behavior of cold rolled steel in artificial seawater in the presence of Bacillus subtilis C2

• Corrosion of cold rolled steel in the presence of Bacillus subtilis C2 was studied.
• Bacillus subtilis C2 clearly decreased the pH value of the solution.
• Biofilm gradually formed on the surface of cold rolled steel after 10 h immersion.
• Bacillus subtilis C2 accelerated firstly and then retarded the corrosion clearly.
• Corrosion of cold rolled steel was related to the co-effect of pH and biofilm.

Effect of Bacillus subtilis C2 (BS) on the corrosion behavior of cold rolled steel (CRS) in artificial seawater has been studied. A visible decrease in pH value and a noticeable decrease in open circuit potential were observed in solutions containing BS compared to the sterile solutions. Biofilm was evidently observed on CRS surface after immersion in solution containing BS for some time, the biofilm increased and became more and more compact with increasing immersion time. A significant reduction in the latter corrosion rate was observed although the initial corrosion was clearly accelerated in the presence of BS.