Influence of bio-corrosion film formed on X80 steel in sulfate-reducing bacteria-containing seawater on hydrogen-induced stress corrosion cracking

The influence of the bio-corrosion film on X80 steel surface caused by sulfate-reducing bacteria (SRB)-induced corrosion on hydrogen-induced stress corrosion cracking behavior in marine environment is investigated. The results show that the film produced by SRB metabolism and corrosion on the surface of X80 steel promotes or hinders hydrogen penetration, which in turn affects stress corrosion, depending on the properties of the dynamically evolving film. Defects within the film can provide sites for hydrogen adsorption, facilitating hydrogen entry into the steel and increasing stress corrosion cracking (SCC) susceptibility. Hydrogen content may be responsible for the loss of tensile properties, and the area of the tensile fracture embrittlement zone is closely related to the hydrogen content of the steel. • SRB-induced formed films are dynamically evolving with SRB activity. • Hydrogen content within the steel is controlled by the state and composition of films. • The area of the embrittlement region is closely related to the state of films.