SAA AS 2331.3.9 2001 Edition, November 23, 2001
METHODS OF TEST FOR METALLIC AND RELATED COATINGS METHOD 3.9: CORROSION AND RELATED PROPERTY TESTS - METALLIC COATINGS - POROSITY TESTS - FERROXYL TEST
Published By:Standards Australia International, Ltd. (SAI)
This Standard specifies a method of revealing pores or other discontinuities in metallic coatings that are not visibly affected by ferricyanide and chloride ions during the test period and that are cathodic to iron and steel. This method is especially useful for thick, hard chromium coatings used for wear resistance.
1 With some coating materials, a very thin layer is dissolved by the sodium chloride solution during a 10 minute application period (see Clause 5.2.3). The impact of such dissolution is that potential porosity, i.e. pores that have been covered over by very thin layers, are sometimes re-exposed. Experience has shown that such potential porosity is frequently reexposed during actual service.
2 The test procedures described in this Standard do not necessarily include all of the precautions required to satisfy health and safety aspects. Care should be taken to ensure that the procedures are carried out only by people who have received suitable training. Guidance in the handling and use of hazardous chemicals is given in AS/NZS 2243.1 and AS/NZS 2243.2.