What is ISO 9227?
In a salt spray test according to ISO 9227, corrosion occurs relatively quickly in any galvanized or diffusion galvanized coating. This while in nature, depending on the layer thickness, it is resistant to rust formation for longer than tested. The explanation? In these accelerated tests, the zinc layer cannot build up a protective patina layer, which explains the rapid failure.
According to EN ISO 14713, accelerated corrosion tests on zinc coatings say little about the results in practice.