Study on corrosion resistance of galvanised steel passivated by a silanised cerium-tannic acid solution

• Published in: Surface & coatings technology 2024-10, Vol.494, p.131483, Article 131483
• Main Authors: Zhang, Tianyuan, Wang, Juan, Shen, Jian, Wang, Xiujuan, Fan, Xianjie, Liu, Zhuhan, Bao, Mengting, Wang, Bingtang, Feng, Yi
• Format: Article
• Language: English
• Subjects: Anti-corrosion; Cerium; Corrosion mechanism; Tannic acid
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2024.131483

In this study, a silanised cerium-tannic acid (Ce-TA) passivation solution was developed, and the effects of solution composition and passivation time on the corrosion resistance of galvanised steel were investigated. SEM-EDS, AFM, FTIR, and Raman spectroscopy were used to characterise the silanised Ce-TA-passivated samples. When the concentrations of both cerium nitrate and tannic acid in the passivation solution were 1.5 g/L, and the passivation duration was 45 s, the surface integrity and composition homogeneity of the passivated sample were good. Electrochemical measurements revealed that the |Z|0.01Hz and Rt values of the silanised Ce-TA-passivated samples first increased and then decreased with increasing passivation time. These values also first increased and then decreased with the increase in the amount of Ce-TA. The corrosion resistance efficiencies of the passivated samples exceeded 97 %. The corrosion resistance mechanism of silanised Ce-TA passivation is also discussed. •A green and efficient passivation solution of silanized cerium-tannic acid (Ce-TA) was developed.•This experiment is the first one to integrate Ce-TA with silane for enhancing the performance of silane passivation.•The corrosion resistance of 0.5 g/L, 1 g/L, 1.5 g/L, 2 g/L, 2.5 g/L cerium and tannic acid passivated samples were compared.•The corrosion resistance of passivated samples at 15 s, 30 s, 45 s, 60 s, 70s and 90 s was compared.•The electrochemistry, composition and surface morphology of passivation samples were analyzed in detail.