rates may be higher, protective systems may be required, but these should be considered on an
individual basis. The atmospheric corrosion of steel averages approximately 0.035 mm/side/year,
although localized conditions and pollution may produce a higher rate. In marine environments,
below bed level, corrosion is low, approximately 0.015mm/side/year, whereas the underwater rate
is normally taken as 0.035 mm/side/year. It is only in the low-water zone, the tidal zone, and the
splash zone that the corrosion rate is higher, approximately 0.075 mm/side/year (Corus, 2001).
Figure 5 summarizes the corrosion rates for steel in different environments.
Figure 5. Corrosion rates for steel in sheet piles under different marine