The effect of applied potential on stress corrosion cracking of X80 pipeline steel in acidic soil containing sulfate-reducing bacteria.

Electrochemical experiments, slow strain rate tensile testing (SSRT), and scanning electron microscopy were used to investigate the effect of various applied potentials on the stress corrosion cracking (SCC) of X80 pipeline steel in acidic soil containing sulfate-reducing bacteria (SRB). The results demonstrated that when the anodic potential was applied, X80 steel exhibited sensitivity to SCC, which was attributed to anodic dissolution. The SCC sensitivity initially decreased, but then increased with a negative shift in the applied potential. At −1200 mV, SCC was the most sensitive, which corresponded to the substantial cathodic polarisation and toxic impact of SRB, which increased the risk of hydrogen embrittlement. At −850 mV, the SCC sensitivity was the lowest because cathodic polarisation suppressed anodic dissolution. The experimental results can contribute to the prevention and management of SCC in operational pipelines. [ABSTRACT FROM AUTHOR]