| With the development of ocean exploitation, the requirements for the corrosion resistance of steel components serving in marine environment are more and more restrict. Hot-dip steels have been already found wide application in marine structures, because of its excellent corrosion resistance and low prices. Enhancing the corrosion resistance of hot-dip steels to meet the demands of much long service life of has been pursued. Adding alloying elements to hot-dip plating material can significantly improve the corrosion resistance of hot-dip steels. So far, most relative studies focused on adding a single element to Al-Zn alloy, few investigations on adding multi-alloying elements were reported.This paper investigated the effects of adding different content of Ni, CeO2 and TiO2 to Al-Zn-Si-Mg alloy on the performance of hot-dip Al-Zn-Si-Mg coating. The optimium parameters of hot-dip process were concluded through orthogonal programmed experiments. The powder additives were prepared by mixing and ball milling. Then 20 steel samples were hot-diped in the alloy bath containing additives. The microstructures and composition distrtbutions of the coatings were analyzed by methods of SEM and EDS. The adhesion strength between coatings and matrix were evaluated by scoring tests. Then samples with different coating were subjected to the neutral salt spray experiment and electrochemical measurements to investigate their corrosion behaviors.The experimental results revealed that the coating was divided into surface layer and alloy layer, the surface layer was composed of the Al-rich phaseαand zinc-rich phaseβ, the alloy layer was mainly a variety of intermetallic compounds. The role of the enhancing adhesion strength, Ni>TiO2>CeO2; the role of the improving electrochemical performance, Ni>CeO2>TiO2; the performance of samplees adding CeO2 was better than that of ones adding TiO2 in the neutral salt spray experiment and those adding Ni was the worst.
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