Bacterial corrosion of mild steel under the condition of simultaneous formation of ferrous and sulphide ions

Summary Corrosion of mild steel in cultures of a Pseudomonas species under the condition of simultaneous formation of Fe(II) and S^2- was initially inhibited by inhibiting the anodic reaction, but after long incubation the corrosion process was allowed to continue. When only S^2- was produced, the initial corrosion rate increased for up to 60 h but later declined, probably due to a protective FeS film formed on the metal. Cathodic reactions were affected in a similar fashion as the anode.Extensive pitting corrosion was observed when the mild steel coupons were immersed in bacterial culture producing Fe(IIO) and S^2-, but not in the uninoculated control.