Long-Term Corrosion Behavior of 434 Stainless Steel Coatings on T6061 Aluminum Alloy in Chloride Environments

The low corrosion resistance of aluminum alloy materials in chloride environments limits their application in light metal structural components. In this study, 434 stainless steel (SS) powders with different numbers of scan layers were deposited on T6061 aluminum using high-velocity oxygen fuel (HVOF). Tafel curve, electrochemical impedance spectroscopy (EIS), salt spray, and galvanic corrosion tests were employed to investigate the comprehensive corrosion behavior of the SS coatings in a chlorine environment. The results showed that the porosity of the SS coatings decreased as the scanning layer increased. A lower porosity slowed the penetration of the corrosive solution and led to an enhanced long-term resistance to chloride attacks in immersion and salt spray corrosion. On this basis, the preferred SS4 sample and iron screw composition system was subjected to galvanic corrosion, and its electric current intensity (5.11 × 10−5 A) was two orders of magnitude lower than that of T6061 aluminum (9.14 × 10−3 A), as well as presenting better anti-corrosion behavior.