BS EN ISO 4623-1:2018 pdf download

BS EN ISO 4623-1:2018 pdf download.Paints and varnishes – Determination of resistance to filiform corrosion Part 1: Steel substrates.
10.3 Testing
10.3.1 General
Two alternative procedures are available, based on initiation by dipping In sodium chloride solutIon or by exposure to salt fog. The dipping technique is generally preferable for air-drying and low-durability materials. For high-durability systems such as automobile finishes applied to phosphated steel, the dipping technique may not produce Illiform corrosion and for these systems It Is preferable to adopt the salt log technique. In such cases, the necessary period of exposure to salt fog will depend on the durability of the material under test but should rarely need to exceed 4 h. It should be noted that salt fog exposure is not normally suitable for low-durability materials since with such systems it commonly produces heavy general corrosion spreading from the scribed marks and the liliform corrosion is suppressed
10.3.2 Dipping technique
Immerse the scribed test panels for 30 s to 60 s in the sodium chloride solution (81).
Take the panels out of the solution and remove any drops of liquid remaining on the surface, taking care not to remove the solution from the scribed marks.
Place the panels in the test cabinet (Li) maintained at (40 ± 2) °C and a relative humidity of (80 t 5) %. Repeat the Immersion procedure, as specified above, every 3 or 4 days until the end of the specified test period.
10.3.3 Salt fog technique
Expose the scribed test panels to neutral salt fog as described in ISO 9227 for the specified period.
Take the panels out of the salt fog cabinet and remove any drops of liquid remaining on the surface, taking care not to remove the solution from the scribed marks.
Place the panels In the test cabinet (Li) maintained at (40 ± 2) C and a relative humidity of (80 ± 5) % for the specified test period.
10.4 Inspection of test panels
Where appropriate, at the specified intervals of re-immersion and on completion of the test, inspect the test panels for filiform corrosion (see ISO 4628-10). Do not allow the test panels to become completely dry at any time during the test period or during inspection, as this may affect the development of the filiform corrosion.
11 Evaluation of the degree of filiform corrosion
Evaluation of the degree of filiform corrosion is normally carried out subjectively and reported in general terms such as slight”, moderate or “severe as in 1511 41,211-10. If specified, using the ruler (72) determine the maximum extent of the Illilorm corrosion as described in ISO 4628-10.
If specified, determine corrosion other than filiform about the scribe marks as described in.
If specified, remove the coating with a non-corrosive paint remover and re-examine the substrate.
Photographs of the test panels at the conclusion of the test may be useful in assessing the extent of filiform corrosion.
12 Precision
No relevant precision data are currently available.
13 Test report
The test report shall contain at least the following information:
a) all detatis necessary to identify the product tested:
b) a reference to this dGcument, i.e. ISO 4623-1:2018 c) details of the preparation of the test panels, including
1) the material, the thickness, and the surlace preparation of the substrate (see 9.1 and 2.2),
2) the method of application of the coating material to the substrate, including the duration and conditions of drying between coats in the case of a multi-coat system and details on sealing of the edges and backs of the test panels (If required) (see 9.2).
3) the duration and conditions of drying and ageing (if applicable) of the coating before testing (see 9.3).
4) the thickness, in micrometres, of the dry coating and the method of measurement used in
1S41.2f08. and whether It Is a single coating or a multi-coat system (see 9.4);
d) complete details of the scribing tool and scribe mark made (see 10.2);
e) the method to initiate corrosion, including the period of exposure (see 10.3);
f) the duration of the test (see 10.iZ and 10.3.3);
g) the results of the test as indicated In Clause 11:
h) any deviation, by agreement or otherwise, from the test procedure described;
I) any unusual features (anomalies) observed during the test;
j) the date of the test.