Corrosion Resistance of Electroless Composite Coating in Salt Industrial Materiel

The corrosion resistance of Ni-P based electroless coating in salt industrial material was studied by polarization curves. Corrosion resistance comparison between Ni-P coating and Ni-Sn-P＼Ni-Cu-P alloy coating was performed by analyzing the composition, morphology, mechanical properties and porosity of coatings. The results showed that the corrosion resistance of coating mainly depended on the composition. Higher phosphorus content resulted in better corrosion resistance. Ni-Sn-P coating showed better performance than Ni-Cu-P coating. The composite alloy coating maintained better comprehensive properties which met the needs of salt industrial equipment. The microstructure of the coating affected the corrosion resistance to some extent.