Effect of sulfate reducing bacteria on the galvanic corrosion behavior of X52 carbon steel and 2205 stainless steel bimetallic couple. (March 2023) - Wan, Huihai
Abstract: Effect of sulfate reducing bacteria (SRB) on the galvanic corrosion between 2205 SS (stainless steel) and X52 carbon steel in enriched artificial seawater (EASW) was comprehensively investigated, which was significant for understanding the microbiologically influenced corrosion of bimetallic composite pipelines. Electrochemical tests indicate that the galvanic effect in the SRB-containing medium was higher than that in the sterile medium. The coupling also promoted the corrosion of 2205 SS in biotic medium with a 13-fold increase in weight loss. The galvanic effect could increase the sessile cell density and accelerate the deterioration of the passive film of 2205 SS. Highlights: Sulfate reducing bacteria (SRB) can promote 2205 SS/X52 couple galvanic corrosion. In the presence of SRB, coupled 2205 SS exhibits higher weight loss (13 times) and pitting rate (2.4 times) than that of uncoupled one. The cathodic polarization will promote the attachment of SRB to the surface and destroy the passive film of coupled 2205 SS. The Hilbert-Huang transform (HHT) is introduced to analyze the galvanic current data, which indicates that electrode reaction is accelerated by SRB.