Corrosion Testing determines the resistance of materials to corrosion under certain environmental conditions, including temperature, humidity and saltwater. Since all metals and alloys are susceptible to corrosion, corrosion test results can help businesses make sound decisions. The effects of corrosion can be costly and devastating, so it generally makes sense to perform testing before damage occurs, often during product design. Corrosion testing is an important step in material selection in order to establish the suitability of materials for their intended use. Corrosion analysis can also help identify a corrodent or an environmental cause if an unexpected corrosion problem occurs. Standardmark Laboratory offers a wide range of corrosion testing in meeting our customer needs.
ASTM B117 & ISO 9227
Salt spray testing is relatively inexpensive, well standardise and reasonably repeatable approach. Most of the salt spray testing aims to maintain coating processes such as pre-treatment and painting, electroplating, galvanizing, and the like, on a comparative basis, rather than analysing corrosion resistivity. For example, pre-treated + painted components must pass 96 hours Neutral Salt Spray, to be accepted for production. The testing plays an important role in quality control of production.
There are many compelling reasons why you should carry out the salt spray test but the main reason is to determine how corrosion will affect your specimen. Diverse surfaces and metals can exhibit varying amounts of resistance to corrosion, and this test allows you to compare this. In addition, the test enables you to determine a surface's propensity to corrode in case it is scratched and assess stickiness coating.
There are many examples of relative salt spray test results such as:
Black Oxide – Samples demonstrates corrosion after 24 to 96 hours
Ruspert Coating (200 & 300) - Samples have no traces of red rust after 1000 hours
Powder Coating – Samples may last for 500 hours before rusting is observed
Results of stainless steel (304 & 316) – Samples vary depending on the finish. However, most samples in this category show almost insignificant corrosion after 1000 hours
There is a limitation of the testing where the testing exposure period is less likely to be correlated to the real-time application.
The standard test method specifies and compares methods for the determination of bimetallic corrosion of metals and coated metals in atmospheric exposure corrosion tests. The methods are intended for the determination of the amount and type of corrosion effect, arising in natural atmospheres, caused by contact with different metals.
The test method evaluates the specimen in a real-time manner by exposing the test sample in the natural environment, and such testing is likely to find out how is the metallic product perform at the local environment.