Study on stress corrosion behavior and mechanism of X70 pipeline steel with the combined action of sulfate-reducing bacteria and constant load

The stress corrosion behavior of X70 pipeline steel with the combined action of SRB and constant load was investigated by constant load experiments and electrochemical testing. The results showed that plastic stress and SRB significantly increased the SCC susceptibility of X70 pipeline steel. SRB promoted the occurrence of pitting corrosion, and there was a synergistic effect of SRB and plastic stress together in promoting the pitting on pipeline steel. The elastic stress was not significant in promoting corrosion. The synergistic effect of tensile stress and SRB was explicated from the perspective of corrosion thermodynamics.