Corrosion Tests in Artificial Atmospheres - Salt Spray Tests First Edition
|Publication Date:||1 January 1990|
|ICS Code (Corrosion of metals):||77.060|
This International Standard specifies the apparatus, the reagents and the procedure to be used in conducting the neutral salt spray (NSS), acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) tests for assessment of the corrosion resistance of metallic materials with or without permanent corrosion protection or temporary corrosion protection.
It also describes the method employed to evaluate the corrosivity of the test cabinet environment.
It does not specify the dimensions of test specimens, the exposure period to be used for a particular product, or the interpretation of results. Such details are provided in the appropriate product specifications.
The salt spray tests are particularly useful for detecting discontinuities such as pores and other defects in certain metallic, anodic oxide and conversion coatings.
The neutral salt spray test applies to
- metals and their alloys;
- certain metallic coatings (anodic and cathodic)1);
- certain conversion coatings1);
- certain anodic oxide coatings1);
- organic coatings on metallic materials.
The acetic acid salt spray test is especially useful for testing decorative coatings of copper + nickel + chromium or nickel + chromium. It has also been found suitable for testing anodic oxide coatings on aluminium.
The copper-accelerated acetic acid salt spray test is useful for testing decorative coatings of copper + nickel + chromium or nickel + chromium; it has also been found suitable for testing anodic coatings on aluminium.2)
1) See annex B.
2) Attention is drawn to the fact that no satisfactory basis for comparison can be derived from this test with regard to the respective quality of nickel + chromium coatings and copper + nickel + chromium coatings, because the reagent used contains a copper ion which promotes corrosion in the presence of nickel but is without influence on copper.