Corrosion Resistance of High-speed Arc Sprayed Zn-Al and Zn-Al-Mg-RE Coatings in Simulated Marine Enviorment

Zn-Al and Zn-Al-Mg-RE coatings were prepared by high-speed arc spraying technology on the surface of Q235 steel. And the corrosion resistance of the coatings in simulated marin enviorment was analyzed by full immersion test, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results show that both Zn-Al and Zn-Al-Mg-RE coatings had a good corrosion resistance in 3.5% NaCl solution and the latter’s corrosion resistance was better than that of the the former’s. The compactness of passivation film caused by the coating corrosion was increased by the rare earth elements of the Zn-Al-Mg-RE coating, and the coating was protected by the passivation film.