Stress corrosion cracking of X80 steel heat-affected zone in a near-neutral pH solution containing Bacillus cereus

Abstract

Bacillus cereus (B. cereus) is observed to have varying effects on the stress corrosion cracking (SCC) sensitivity of different microstructures in the simulated heat-affected zone (HAZ) of X80 steel. At open circuit potential (OCP), the SCC sensitivity of different microstructures increased from 3.40–7.49% in an abiotic medium to 10.22–15.17% in a biotic medium. At −0.9 V (SCE), it increased from 22.81–26.51% to 35.76–39.60%. The increment in SCC sensitivity upon exposure to B. cereus was highest in the coarse-grained HAZ (7.68 and 16.79% at OCP and −0.9 V, respectively), followed by the intercritical and fine-grained HAZs. Owing to differences in the phase composition, grain boundary type, dislocation density, and surface volta potential, the initial adhesion number and position of B. cereus in the microstructure of the HAZ were differed, resulting in different sensitivities to SCC.