ATMOSPHERIC CONDITIONS AND DURABILITY OF WEATHERING STEELS.

Corrosion is mainly influenced by climatic factors: temperature and humidity and by pollution factors: SO//2 and chlorides (in maritime environments). A good patina is achieved provided some SO//2 is present in the air together with alternate periods of moistening and drying. Continuous moistening must be avoided. In moderate marine climates, where the aggressiveness is important, a special grade of weathering steel must be used.