Effect of magnetic field on stress corrosion cracking induced by Sulfate-reducing bacteria

Buried pipes are often affected by microorganisms and magnetic fields. In this paper, the stress corrosion cracking (SCC) behavior of X80 steel under the combined effect of magnetic field (MF) and sulfate-reducing bacteria (SRB) was studied by electrochemical and slow strain rate tensile testing. The synergistic effect of MF and SRB on SCC was expounded for the first time. Results confirmed that the sensitivity of SCC increased under 0~20 mT, which was attributable to the fact that the MF promoted the entry of diamagnetic corrosion anions into the corrosion pit and accelerated the paramagnetic Fe2+ to detach from the steel surface. MF and SRB not only independently improved the stress corrosion sensitivity of steel, but also had a synergistic effect. MF changed the arrangement of the biofilm. At 30 mT, the sensitivity of SCC decreased, which was due to the excessive MF inhibited the growth of SRB.