“…Additionally, corrosion of carbon steel was promoted due to that Fe 3+ produced from IOB metabolism can rapidly oxidize Fe 0 to Fe 2+ (Wang et al, 2014; Liu et al, 2016; Liu H. et al, 2018). The relationship of IRB to corrosion was not straightforward, i.e., IRB may enhance corrosion under some circumstances, or have a passivating effect on corrosion in others (Duan et al, 2008; Mehanna et al, 2008; Esnault et al, 2011; Schutz et al, 2014, 2015; Cote et al, 2015; Starosvetsky et al, 2016). Corrosion acceleration induced by IRB was mainly related to that the reduction of insoluble ferric compounds to soluble ferrous ion facilitated the removal of protective corrosion products on steel surface (Esnault et al, 2011; Starosvetsky et al, 2016), and bio-oxidation of H 2 resulted in high anodic dissolution rate of steel (Schutz et al, 2014, 2015).…”