Long term atmospheric corrosion behavior of metals exposed to tropical marine environment in India

Book · Sun Oct 01 00:00:00 EDT 1995

OSTI ID:109927

Subramanian, G; Palraj, S ^[1]; Ananth, V; Balakrishnan, K ^[2]

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1. CECRI Unit, Mandapam (India). Corrosion Testing Centre
2. Central Electrochemical Research Institute, Karaikudi (India)

The corrosion behavior of commercially available lead and aluminium alloy tubes and rods has been studied for a period of 2 years in the tropical marine environment of Mandapam. The monthly and quarterly corrosion rate values of the alloys are directly related to and determined by the weathering conditions, such as salt content in the air, percentage relative humidity, temperature and rainfall, prevailing during a particular monsoon. The exponential decrease in the corrosion rate values of the cumulative exposures of the alloys, in general, are indicative of the protective nature of the corrosion product film on its surface. The corrosion products on lead and aluminium alloys are analyzed with X-ray diffractometer. Formation of Lead chloride on the monthly exposure surfaces lead to uniform corrosion attack, whereas formation of lead oxychloride and antimony oxychloride on cumulative exposure surfaces of lead result in localized pitting. Formation of Al{sub 2}O{sub 3}, Al(OH){sub 3}, AlCl{sub 3}{center_dot}6H{sub 2}0 and ALO(OH) on the surfaces of the aluminium alloys influences the pitting corrosion over the period of exposure. The pitting corrosion behavior of lead and aluminium alloys are discussed in the light of pit density, pitting probability and size of pit. The surface characteristics of lead over the period of exposure are highlighted with scanning electron microscope. Heterogeneity in the aluminium alloy matrix favor pitting and intergranular corrosion.

• OSTI ID: 109927
• Report Number(s): CONF-950304-; TRN: IM9543%%228
• Resource Relation: Conference: Corrosion `95: National Association of Corrosion Engineers (NACE) international annual conference and corrosion show, Orlando, FL (United States), 26-31 Mar 1995; Other Information: PBD: 1995; Related Information: Is Part Of Corrosion/95 conference papers; PB: 5788 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
LEAD
CORROSION
ALUMINIUM ALLOYS
INDIA
CORROSION PRODUCTS
SODIUM CHLORIDES
ATMOSPHERIC PRECIPITATIONS
CORROSION PROTECTION
CHEMICAL COMPOSITION
ALUMINIUM OXIDES
ALUMINIUM HYDROXIDES
ALUMINIUM CHLORIDES
EXPERIMENTAL DATA
CORROSION RESISTANT ALLOYS
AIR POLLUTION
POLLUTANTS
SEAWATER