The synergistic effect of parallel magnetic field and sulfate-reducing bacteria on stress corrosion cracking of buried X80 pipeline steel

Abstract

In this work, the synergistic effect of parallel magnetic field and sulfate-reducing bacteria (SRB) on stress corrosion cracking (SCC) of X80 pipeline steel in buried soil environments was investigated for the first time by electrochemical experiments, slow strain rate tensile tests (SSRT) and surface characterization. The results showed that the parallel magnetic field suppressed electrochemical corrosion in a sterile environment; the SCC susceptibility decreased with increasing magnetic field strength (0–100 mT). The magnetic field and SRB synergistically promoted the formation of a dense film layer on the surface of the specimen in the inoculated SRB environment. The dense film layer suppresses the local corrosion of the metal and therefore the SCC susceptibility is reduced. The suppression effect no longer increased significantly when the magnetic field strength reached 75 mT. The synergy between the parallel magnetic field and the SRB was responsible for the reduced susceptibility of the SCC. This work contributed to a more in-depth study of the mechanisms of pipeline SCC and the development of pipeline SCC prevention technologies.