This International Standard specifies guiding corrosion
values and the characteristics of corrosion for
the corrosivity categories defined in IS0 9223.
Guiding corrosion values give corrosion rates for
standard structural materials and can be used for
engineering calculations. The guiding corrosion values
specify the technical content of each of the individual
corrosivity categories for these standard
This International Standard can be used to predict
the service life for metals, alloys and, in some
cases, for metallic coatings used in atmospheres
corresponding to different corrosivity categories
(see table 1). The guiding corrosion values also provide
a technical basis for determining the need for
protective measures and other engineering purposes.
The guiding corrosion values are based on experience
obtained from a large number of site exposures
and service performances. Corrosion rates
expected for a given corrosivity category may be
exceeded in the vicinity of special design features
which cause localized or galvanic corrosion.