Selective corrosion behavior of X80 steel heat affected zone by SRB in coastal saline soil

The corrosion behavior of heat affected zone of X80 pipeline steel was investigated in coastal saline soil with or without sulfate-reducing bacteria (SRB). In the sterile soil environment, the diameter, depth, and density of corrosion pits detected in the coarse grain zone (CGZ) were larger than those in the fine-grained zone (FGZ) and fusion zone (FZ). In the soil environment inoculated with SRB, the microbes enhance the corrosion of FGZ, CGZ, and FZ. The corrosion susceptibility of CGZ coupons is stronger in the presence of SRB than those of FGZ and FZ coupons.