Corrosion of stainless steel water storage tanks exposed in coastal atmospheric conditions

Results of corrosion survey for stainless steel tanks used in water storage at various coastal areas are presented. Corrosion damages were revealed at both the outer and inner surfaces of tanks made of 304 and 201 steel grades. Corrosion deterioration was more severely observed for the atmospheric areas with higher airborne salinity and time of wetness.  Corrosion products examined by visual inspection and SEM-EDX technique show relatively distinctive characteristics for outer and inner surfaces which are attributed to different mechanisms of corrosion initiated by various corrosive agents in the atmosphere. Atmospheric chlorides from airborne sources are considered the main reason for causing corrosion of 304 and 201 steel grade water tanks.