Evaluación de la corrosión inducida por bacteria sulfato reductora en un acero inoxidable 316L

L stainless steel is widely used in the chemical, petrochemical, thermal, and nuclear industries because of its excellent resistance to corrosion, good mechanical properties at high temperatures, and welding applicability by different processes. This steel, however, is highly susceptible to microorganism-induced corrosion, which results in significant damage involving huge losses to industry. This study assessed the relationship between the microstructure and the corrosion induced by sulphate-reducing bacteria (SRB) in a stainless austenitic grade steel, videlicet, the 316L, electrically welded with a like filler material known as ER316 filler. The microstructural characterization and the assessment of the corrosion were estimated by scanning electron microscopy and energy dispersive X-ray spectrometry (EDS) chemical microanalysis. Furthermore, transmission electronic microscopy (TEM) was used to determine what phases and precipitates were present in the steel sheets before subjecting them to harm. The results show that AISI 316L experimented corrosion by SRB, i.e., anaerobiosis and sulphur production interrupted the passive film formed on the steel surface, thus prompting a localized corrosion featuring the typical pits and craters.