Study of pitting corrosion of L245 steel in H2S environments induced by imidazoline quaternary ammonium salts

The corrosion characteristics of L245 steel were analyzed under H2S atmosphere in stratum water with imidazoline quaternary ammonium salt (IM), and IM mixed with octylphenol polyoxyethene ether (OP). L245 suffered pitting corrosion in solutions with only IM, but pitting corrosion was inhibited in solutions with IM and OP. Local damages of the adsorbed IM film appeared on the steel surface in solutions with only IM. While Cl− accumulated on these areas, surface potentials were lower than surrounding areas, and a small anode/large cathode galvanic corrosion system was formed. The influence of inhibitor on pitting corrosion for L245 steel was discussed.