Experimental study on corrosion resistance of Zn–Al–Mg alloy coating of high-strength steel wires for bridge cables
Anti-Corrosion Methods and Materials
ISSN: 0003-5599
Article publication date: 6 September 2023
Issue publication date: 20 November 2023
Abstract
Purpose
This paper aims to figure out the conundrum that the corrosion resistance longevity of steel wires for bridge cables was arduous to meet the requirements.
Design/methodology/approach
The “two-step” hot-dip coating process for cable steel wires was developed, which involved first hot-dip galvanizing and then hot-dip galvanizing of aluminum magnesium alloy. The corrosion rate, polarization curve and impedance of Zn–6Al–1Mg and Zn–10Al–3Mg alloy-coated steel wires were compared through acetate spray test and electrochemical test, and the corrosion mechanism of Zn–Al–Mg alloy-coated steel wires was revealed.
Findings
The corrosion resistance of Zn–10Al–3Mg alloy-coated steel wires had the best corrosion resistance, which was more than seven times that of pure zinc-coated steel wires. The corrosion current of Zn–10Al–3Mg alloy-coated steel wires was lower than that of Zn–6Al–1Mg alloy-coated steel wires, whereas the capacitive arc and impedance value of the former were higher than that of the latter, making it clear that the corrosion resistance of Zn–10Al–3Mg was better than that of Zn–6Al–1Mg alloy coating. Moreover, the Zn–Al–Mg alloy-coated steel wires for bridge cables had the function of coating “self-repairing.”
Originality/value
Controlling the temperature and time of the hot dip galvanizing stage can reduce the thickness of transition layer and solve the problem of easy cracking of the transition layer in the Zn–Al–Mg alloy coating due to the Sandelin effect.
Keywords
Acknowledgements
This work was supported by the Key R&D project of Science and Technology Department of Guangdong Province (2019B11106002) and National Natural Science Foundation of China under Grant No. 52108292. The authors also would like to express gratitude to the reviewers for their comments.
Citation
Hu, D., Song, S., Zhang, Z. and Wang, L. (2023), "Experimental study on corrosion resistance of Zn–Al–Mg alloy coating of high-strength steel wires for bridge cables", Anti-Corrosion Methods and Materials, Vol. 70 No. 6, pp. 459-468. https://doi.org/10.1108/ACMM-07-2023-2858
Publisher
:Emerald Publishing Limited
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