Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces

ASTM D610 enables us to assess the degree of rusting of a painted steel surface through the use of the visual aid that is provided by this method. Indeed, this practice corresponds to a standardized way which allows to evaluate the amount and the distribution of visible surface corrosion on a coated surface. More specifically, ASTM D610 was created as a means to qualify homogeneously the level of corrosion observed on aged samples. Hence, ASTM D610 has to be used with methods of the likes of ASTM B117 , ASTM D714 and ASTM G85 . Micom Laboratories offers the ASTM D610 test as part of its corrosion testing services .

ASTM D610 uses and factors to consider

Evaluation of the degree of rusting of painted steel surface

The goal of ASTM D610 is to provide a standardized means to evaluate the degree of rusting of painted surfaces with the aid of visual examples. Indeed, the photographs that are issued by this method are categorized by a 0 to 10 scale in function of the percentage of the rusted surface that is visible and by the distribution of the rust. In fact, a lower grade corresponds to a large corroded surface while a high grade is associated with a small rusted surface. Moreover, by assessing the amount of rust that is beneath or through a paint film, it is possible to determine if the coating system ought to be replaced or repaired, because it is a great indicator of the remaining lifetime of the latter.

The main factors that are in play when conducting this test protocol are: the classification of the rust distribution and the degree of rusting.

ASTM D610 rating corrosion

Rating corrosion by ASTM D610 is twofold: the degree of rusting and the rust distribution. The rating is listed in table 1.

Table I: Specifications of the corrosion rating

Degree of rusting0> 50%
1> 33.0% and ≤ 50.0%
2> 16.0% and ≤ 33.0%
3> 10.0% and ≤ 16.0%
4> 3.0% and ≤ 10.0%
5> 1.0% and ≤ 3.0%
6> 0.3% and ≤ 1.0%
7> 0.1% and ≤ 0.3%
8> 0.03% and ≤ 0.1%
9> 0.01% and ≤ 0.03%
10≤ 0.01%
Classification of the rust distributionSpot rustThe rusting is condensed in a few localized areas of the painted surface.
General rustThe rusting is randomly distributed in sizes and in areas throughout the painted surface.
PinpointThe rusting is spread through the surface as small individual specks of rust.
HybridThe rusting combines attributes of at least two of the previous classification.

Other test methods related to ASTM D610

For additional related test methods, we invite you to read more about ASTM B117 , ASTM G85 and ASTM D714.

If you have any questions about the ASTM D660 test, we invite you to contact our material testing lab today. It will be our pleasure to answer your questions and help you with your custom material testing requirements.