ISO 8993:2010 pdf free download – Anodizing of aluminium and its alloys – Rating system for the evaluation of pitting corrosion一Chart method.
ISO 8993 specifies a chart rating system based on standard charts that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests.
This rating system is applicable to pitting corrosion resulting from
— accelerated tests,
— exposure to corrosive environments, and
— practical service tests.
This International Standard takes into account only pitting corrosion resulting from penetration of the protective anodic oxidation coating.
NOTE ISO 8994 describes a similar rating system based on defined grids.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
significant surface
part of the article covered or to be covered by the coating, for which the coating is essential for serviceability and/or appearance
NOTE 1 Adapted from ISO 2064:1996[h], definition 3.1.
NOTE 2 The edges of an article are not normally included in the significant surface.
2.2
corrosion pit
surface corrosion defect at which the anodic oxidation coating is penetrated
NOTE Discoloration or other surface defects which do not penetrate the anodic coating do not count as corrosion pits.
4 Expression of results
Express the result of the examination as the chart rating and/or the percentage area covered by corrosion pits, as appropriate.
5 Test report
The test report shall include at least the following information:
a) a reference to this International Standard;
b) the type and identification of the product tested and, where appropriate, the anodizing, exposure and corrosion test procedure;
c) the method of sample preparation used (see 3.1);
d) the comparison method used, for example, whether the comparison was done visually or electronically; in the case of comparison by an electronic method, the specification of the test apparatus shall also be given;
e) the chart rating and/or the percentage area covered by corrosion pits (see Clause 4);
NOTE The acceptable chart rating will normally be specified in the relevant corrosion test or product specification.
f) the date of the test.