Corrosion behavior of Limnoperna fortunei on carbon steel in freshwater environments

Limnoperna fortunei (L. fortune) , a representative macrofouling organism in freshwater environments, causes significant degradation to the surfaces of hydraulic engineering materials through prolonged adhesion. The corrosion behavior of L. fortunei on Q345 carbon steel in river water environments was investigated employing topography detection, rust layer identification, corrosion rate analysis, electrochemical measurements, and molecular dynamics (MD) simulation. The results demonstrated that the attachment of mussels decreased the overall corrosion rate of the steel surface, but significantly aggravated pitting corrosion, a localized and highly destructive form of material degradation. The corrosion behavior of Q345 steel in a freshwater environment influenced by L. fortunei was primarily driven by the formation of a restricted microenvironment beneath the mussel shells, which promoted localized anion enrichment, bacterial colonization, and the accumulation of aggressive secretions. These factors collectively intensified electrochemical heterogeneity, accelerating pitting initiation and propagation. These findings emphasize the critical need for mitigation strategies to address localized corrosion caused by biofouling in hydraulic engineering applications.