Electrochemical corrosion, hydrogen penetration and stress corrosion cracking behavior of X80 steel heat-affected zone in sulfate-reducing bacteria-containing seawater

The electrochemical corrosion, hydrogen penetration, and stress corrosion cracking (SCC) behaviors of simulated intercritical heat-affected zone (ICHAZ), fine-grained heat-affected zone (FGHAZ), and coarse-grained heat- affected zone (CGHAZ) are investigated in inoculated seawater. The results show that sulfate-reducing bacteria (SRB) accelerates corrosion and increases SCC susceptibility. However, there are variations in the degree of influence of SRB on corrosion of different microstructures. The differences are closely associated with the amount and location of SRB adhesion to the simulated HAZ microstructure. This is attributed to differences in grain boundary types, dislocation density, local strain accumulation and surface Volta potential of the simulated microstructures.