When a laboratory-accelerated test simulates the changing conditions to which automotive finishes are exposed, more realistic corrosion failures are produced.

Cyclic corrosion tests are effective for evaluating a variety of corrosion mechanisms, such as general, galvanic, crevice, etc. The cyclic corrosion tests make use of many types of environments, such as salt fog (Practice B 117), humidity (Practice D 2247 or Practice D 1735) and dry conditions to accelerate metallic corrosion. In cyclic corrosion testing, specimens can be exposed to many different types of environmental conditions and cycled from one environment to another.

In all tests it is imperative to expose control specimens with an established corrosion performance together with the test specimens to make a comparison possible of the corrosion performance of the two sets.

Guidelines are included for those who evaluate the corrosion performance of painted metal parts in cyclic corrosion tests. These guidelines are intended to help ensure that the results of the tests can be used to reach conclusions concerning the variables under study, without being affected by the test procedure itself. The guidelines are also intended to assist users of this type of test in obtaining good inter-laboratory agreement of results.

This guide is not intended to be a substitute for the described cyclic corrosion test standard. In all cases, the laboratory should obtain the most recent published standard for complete details. The published standard supersedes this guide.