Comparative analysis of corrosion resistance of pipeline steels exposed to sulfate-reducing bacteria: Insights on L360, L245NS and antibacterial steels
Shuyu He, Kongyang Wang, Yongyang Zhao, Yao Lu, Ruijing Jiang, J.X. Li, Yong Xiang
Abstract
In response to the microbiologically influenced corrosion (MIC) issues encountered in oil and gas pipelines, a comparative study was conducted on the corrosion properties and mechanisms of pipeline steels L360, L245NS, and antibacterial steel in environments containing sulfate-reducing bacteria (SRB) using the weight-loss method, surface analysis techniques, and electrochemical tests. The results showed that both the uniform corrosion rate and pitting rate followed the order: L360 > L245NS > antibacterial steel. Electrochemical tests further confirmed that the antibacterial steel demonstrated superior corrosion resistance, with the highest self-corrosion potential and a corrosion current density one-fifth that of L360 steel. Additionally, the antibacterial steel is more prone to passivation in the SRB environment. After 7 days of exposure, the sum of its charge transfer resistance and biofilm resistance was approximately 2.9 times that of L245NS steel and 3 times that of L360 steel. The addition of Cu to the antibacterial steel may contribute to inhibiting microbial growth and preventing biofilm formation, though this mechanism is controversial.