Page 397 - Corrosion Engineering Principles and Practice

366 C h a p t e r 9 A t m o s p h e r i c C o r r o s i o n 367

Sapporo
Extremely severe
Severe
Moderate
Mild
Negligible
Sendai

Tokyo
Osaka
Kitakyushu

FIGURE 9.37 Corrosivity map of Japan.

9.6 Atmospheric Corrosion Tests
For many years, different individuals and organizations have been
putting specimens out in the atmosphere in all kinds of tests and
shapes. There has been an attempt to standardize some of these tests,
as well as the method of reporting the results. When initiating
corrosion tests in the atmosphere, these standardized procedures
should be consulted and used whenever possible.
Flat panels exposed boldly to the environment on special exposure
racks are a common method for testing materials and protective
coatings (Fig. 9.39). Various other specimen configurations have been
used, including stressed U-bend or C-ring specimens for stress
corrosion cracking (SCC) studies, and crevice assemblies to verify the
susceptibility of specific configurations (Fig. 9.40).