The influence of sulfate reducing bacteria (SRB) and CaCO3 scale layer on the corrosion behavior of 20# steel was studied by laboratory simulation experiment. The uniform corrosion rate was studied by corrosion weight loss method.The corrosion electrochemical behavior of 20# steel in the injected aqueous solution was studied by electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP). The morphology and composition of corrosion products on the surface of 20# steel were analyzed by scanning electron microscopy (SEM), EDS and Raman spectroscopy. The pitting pit depth of 20# steel was analyzed by laser confocal microscopy (CLSM). The results show that there is a synergistic effect between SRB and CaCO3 scale layer. The porosity of CaCO3 scale layer and the anaerobic environment under the scale layer provide convenient conditions for the adhesion and growth of SRB. The inoculation of SRB can promote the uniform corrosion and local corrosion of 20# steel under the CaCO3 scale layer.
