Volvo Laboratory Study of Zinc-Coated Steel Sheet - Corrosion Behavior Studied by a Newly Developed Multifactor Indoor Corrosion Test 890705
An accelerated multifactor laboratory corrosion test with high correlation with respect to outdoor Volvo scab and field exposure is under way. It uses a mixture of SO2 and NO2 in ppm amounts at high humidity, combined with periodic soaking of the samples in acidified, diluted sodium chloride solution.
A broad representation of precoated steel materials with cathodic electro-deposition primer and the full car body paint system was used to correlate the results to outdoor field and scab exposure.
The results show that the conventional electrogalvanized and hot-dip galvanized zinc-coatings seem, from point of view of cosmetic corrosion, to be as good a choice as new generation precoating. The tested hot-dipped zinc-iron alloy coating performed very well, and was much more insensitive to galvanic corrosion than the zinc-coatings.
The thickness of the precoating is generally an essential parameter for the cosmetic performance of painted panels.
13 weeks of the multifactor test correspond to approximately 15 months of Volvo outdoor scab exposure with high accuracy for the majority of materials.
Citation: Ström, M., "Volvo Laboratory Study of Zinc-Coated Steel Sheet - Corrosion Behavior Studied by a Newly Developed Multifactor Indoor Corrosion Test," SAE Technical Paper 890705, 1989, https://doi.org/10.4271/890705. Download Citation
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SAE Transactions Journal of Materials and Manufacturing-V98-5