ASTM D610-08 (R2019) pdf free download.Standard Practice for Evaluating Degree of Rusting on Painted Steel Surfaces.
1.1 This practice covers the evaluation of the degree of rusting on painted steel surfaces, The visual examples which depict the percentage of rusting given in the written specilica(1011 5 form part of the standard. In the event of a dispute, the written definition prevails. These visual examples were developed in cooperation with SSPC: The Society for Protective Coatings to further standardization of methods. The photographs can be used to estimate the percentage of other coating defects on various substrates. This standard does not include evaluation of rust propagation around an initially prepared scribe, score, or holiday.
3. Significance and Usc
3. 1 The amount of rusting beneath or through a paint film is a significant factor in determining whether a coating system should be repaired or replaced. This practice provides a standardiied means for quantifying the amount and distribution of visible surface rust.
3.2 The degree of rusting is evaluated using a zero to ten scale based on the pcrccntagc of visible surface rust.
3.3 The distribution of the rust is classified as spot rust. general rust, pinpoint rust or hybrid rust.
4. Interferences
4.1 The visual examples that are part of this practice and the associated rust-grade scale cover only rusting evidenced by visible surface rust.
4.2 The use of the visual examples requires the following cati Lions:
4.2. 1 Some finishes are stained by rust. This staining must not be confused with the actual rusting involved.
4.2.2 Accumulated dirt or other material may make accurate determination of the degree of rusting difficult.
4.2.3 Certain types of deposited dirt that contain iron or iron compounds may cause surface discoloration that should not be mistaken for corrosion.
4.2.4 Failure may vary over a given area. I)iscretion must therefore he used when selecting a single rust grade or rust distribution that is to he representative of a large area or structure, or in subdividing a structure br evaluation.
4.2.5 The color of the finish coating should be akcn into account in evaluating surfaces as failures will he more apparent on a finish that shows color contrast with rust, such as used in these reference standards, than on a similar color, such as an iron oxide finish.
5. Procedure
5.1 Select an area to be evaluated.
5.2 Determine the type of rust distribution using definitions in Table I and visual examples in Fig. I, Fig. 2. and Fig. 3.ASTM D610 pdf download.