Effect of Sulfate Reducing Bacteria on Pitting Behavior of Carbon Steel in H₂S Environment

API-RP38 culture medium was used to culture sulfate-reducing bacteria (SRB) extracted from oil field wastewater, and the growth of SRB was observed. The adsorption morphology of SRB on the surface of samples was observed by scanning electron microscopy (SEM). Weight loss method and electrochemical method were used to study the effects of SRB on corrosion of carbon steel under the conditions of high H₂S and high salinity. The results showed that SRB had a significant acceleration effect on the corrosion of carbon steel, and the corrosion morphology was mainly pitting. In the environments with high H₂S and salinity, SRB adsorbed on the sample could survive and accelerate the corrosion of carbon steel. In H₂S environment, under the condition of containing SRB, the corrosion potential of the sample decreased with the increase of the immersion time, the corrosion current density increased, the corrosion product film resistance and the charge transfer resistance both decreased, and the corrosion accelerated. Under sterilizing conditions, as the immersion time was prolonged, the corrosion potential of the sample increased, the corrosion current density decreased, the resistance of the corrosion product film and the charge transfer resistance increased, and the corrosion slowed down.