Insight into the galvanic corrosion behavior of the LHE Cd-Ti 300 M steel coupled with TC4 titanium alloy in different atmospheric environments

Atmospheric galvanic corrosion behavior of low hydrogen embrittlement Cd-Ti plated (LHE Cd-Ti) 300 M steel coupled with anodized TC4 titanium alloy was investigated in different natural environments. The galvanic corrosion between LHE Cd-Ti 300 M steel and anodized TC4 titanium alloy exists in both atmospheres, and high concentrations of Cl^- and SO₄^2- in industrial-marine atmosphere greatly enhance the galvanic effect. The atmospheric corrosion of initiates from pitting on Cd-Ti coating. Once the corrosive media penetrate the coating and reach the coating-matrix interface, corrosion products of matrix generate and accumulate. The oxidized Cr-containing film in semi-rural atmosphere showed better protectiveness on the matrix.