Abstract:

Two hot-dip galvanized products are applied onto the steel substrates, then the specimens are tested for 5000h by the neutral salt spray and there are obvious differences in the anti-corrosion performance between the coatings. The thickness loss of coatings, crystal material compositions and microstructures of the coatings are analyzed by Zinc coating thickness loss test method, differential scanning calorimetry (DSC), and X-ray diffraction analysis (XRD). The results show that there is no significant difference of the corrosion products and corrosion mechanisms between two coatings. Nevertheless, the hot-dip galvanized production process, the degree of densification of the corrosion products in coating are the primary factors influencing the anticorrosion performance of the hot-dip galvanized coating.

Key words: hot-dip galvanized; neutral salt spray test; anti-corrosion performance