Corrosion test information is often needed for selecting metallic construction materials for chemical process and other equipment. Usually, the information most readily available is laboratory corrosion test results for a specific set of controlled conditions. However, these conditions frequently do not represent service environments of specific equipment. Varying levels of contaminants, aeration, flow, temperature variations, liquid and/or vapor exposure, and other factors can make service conditions difficult or impossible to duplicate in the laboratory. Thus, in many instances, the more accurate method of evaluating metals for a particular application is by exposing metallic test specimens in the field or actual service environment. These methods can provide a much more accurate estimate of service performance than laboratory testing.

As with any corrosion study, careful design of the field test program and accurate interpretation of the test results are needed to develop meaningful data that lead to a conclusive study and correct conclusions. To that end, this standard recommended practice aids the design, implementation, and evaluation of field corrosion testing programs using metallic test specimens. No other materials or testing are addressed in this standard. This standard is particularly helpful when used in conjunction with ASTMG 4. 1 This standard was prepared by NACE Task Group T-5A-29, a component of Unit Committee T-5A on Corrosion in Chemical Processes, and is issued under the auspices of Group Committee T-5 on Corrosion Problems in the Process Industries.

1.1.1 This standard describes how field corrosion testing using metallic test specimens is conducted, what types of corrosion information may be obtained, and how test racks and test specimens are designed. A summary of critical data that must be recorded is provided. Guidelines for interpreting and reporting test results are also discussed.

1.1.2 Corrosion fatigue can be a serious problem, but no field methods of testing are known. Therefore, corrosion-fatigue testing is outside the scope of this standard.