Complicated Damage Characteristics of Cavitation and Corrosion in Sea Water with Sealing Treatment for AI-3Mg Arc Sprayed Coating

摘要

To improve the corrosion resistance of SS400 steel in marine environment, organic and inorganic composite ceramic sealing (hereinafter called "hybrid sealing") was performed after Al-3Mg arc sprayed coating. Furthermore, to examine the complicated damage behavior of cavitation and corrosion, electrochemical experiments were conducted simultaneously in cavitation environment. As a result, in cavitation environment, the passive state film was destroyed early, lowering corrosion resistance. In addition, cavitation erosion-corrosion damages were concentrated in the cavitation-affected zone due to different stress distributions formed in the coating layer due to the cavitation bubble impact pressure. Moreover, hybrid sealing applied to the Al-3Mg thermal sprayed coating greatly improved corrosion resistance in the static condition, but somewhat decreased corrosion and cavitation resistance in the complicated environment of cavitation and corrosion.