Corrosion mechanism of TA2/Q345B composite plate in marine solution

Purpose This study aims to investigate corrosion mechanism of titanium–steel composite plates in simulated marine environments. Design/methodology/approach Corrosion behavior of TA2/Q345B composite plates was investigated via immersion test. Corrosion product was analyzed by scanning electron microscopy combined with energy-dispersive spectroscopy, X-ray diffraction, potentiodynamic polarization tests and electrochemical impedance spectroscopy. Findings Corrosion near the interface region originated from galvanic corrosion and later transformed into a combination of galvanic corrosion and crevice corrosion. The accelerating effect of galvanic corrosion in the far-interface region has been weakened, its corrosion behavior is similar to the self-corrosion behavior of carbon steel in the marine environment. Originality/value Research on corrosion behavior of titanium-steel composite plates is not sufficient. It is necessary to understand their corrosion mechanism, especially the reasons for differences in corrosion behavior between the near-interface region and the far-interface region.