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Automotive - acceptance criteria after salt spray test

2006

Hi,

I've been talking about Zinc (Cr 3) coating of Iron fasteners systems (nut) for an electronic device located inside the passengers compartment in a not visible place.

I know that after testing there can be three different acceptance criteria:

1) no white rust (zinc corrosion) after testing
2) no white rust (zinc corrosion) after the first XX h and no red rust (iron corrosion) after testing
3) no red rust (iron corrosion) after testing and no more than YY% of white rust

For an iron component located in a not visible place, can be the presence of white rust acceptable? The reference standard of our customer request only that after testing the components still functioning (the nut can be unscrewed)

Thanks in advance
sorry for my bad English

Alex
Test Engineer - Milan, ITALY