LAUSR

Abstract In this work, corrosion of an abandoned X52 pipeline steel containing artificial pits with varied depths was investigated in a simulated soil solution containing sulfate-reducing bacteria (SRB). Bio-testing, electrochemical measurements and surface analysis techniques were used to study the SRB-induced corrosion outside and inside the pits. Results show that the SRB tend to accumulate on the specimen surface (i.e., outside the pits), rather than inside the pits, resulting in accelerated corrosion of the steel. As the depth of the pit increases, there are fewer SRB adherent to the steel of the pit wall. Thus, compared to the specimen surface, the pits experience a reduced MIC. A galvanic effect exists between the outside and inside the pits, with the former serving as the anode and the latter as the cathode, further enhancing the corrosion of the steel outside the pits.