Cyclic Corrosion Testing

A more realistic way to perform salt spray tests

Real life atmospheric exposures tend to include cycles of both dry and wet environmental conditions. 

Cyclic corrosion testing helps to better replicate these real life environment changes in a accelerated laboratory conditions.

Temperature and Humidity

Contrary to more traditional static corrosion tests such as the salt spray test, cyclic corrosion testing results in the relative corrosion rates, structure and morphology that are more similar to those observed outdoors. 

Although there are numerous ways to test for corrosion resistance using cyclic corrosion, some of the more popular cyclic corrosion tests methods include:

ASTM G85 Test is a standard practice for modified salt spray (fog) testing. Although ASTM G85 is based on ASTM B117, it offers more aggressive test conditions such as using a test solution with a lower pH, alternating between corrosive and neutral atmosphere or by using an aggressive electrolyte mix.

ASTM G44 Test is a standard practice for exposure of metals and alloys by alternate immersion in neutral 3.5 % sodium chloride solution. This test is mainly used for aluminum and ferrous alloys as well as any other alloy susceptible to chloride ions.

ASTM D5894 Test is a cyclic salt fog / UV exposure of painted metal test.  This test consists of exposing samples to alternating exposures in a fog/dry cabinet and a UV/condensation cabinet.

ASTM D2247 tests for water resistance of coating in 100% relative humidity.

ASTM D4585 tests for rain and condensing humidity.

ASTM D1735 tests how the coating of your products is resistant to water under highly condensing humid conditions.

Cyclic corrosion tests are effective for evaluating a variety of corrosion mechanisms, including general corrosoin, galvanic corrosion, and crevice corrosion.

What products (size, types) can be tested in a corrosion testing apparatus?

Products tested to both ASTM B117 and ASTM G85 can vary a lot both in sizes and in nature. The most standard sample will be a 3 inch by 6 inch painted thin panel. However much large and 3D samples are often tested. 

The size of sample tested products can vary greatly from street lights, bicycles, telecommunications devices, car parts and much more.