CORROSIVITY OF THE ATMOSPHERE ON CARBON STEEL IN A COASTAL ZONE OF THE CANTON OF MANTA IN MANABI, ECUADOR

Abstract

A study based in the atmosphere corrosivity evaluation on carbon steel in a coastal zone of the canton of Manta in Manabí, Ecuador, was carried out. Eight exposure sites were selected at different distances from the coastline. Wooden supports with three dry cloth device for the monthly determination of chloride ion salt deposition and six carbon steel metal specimens of standardized dimensions were placed in each exposure site. Three metallic specimens for monthly and annual measurement of atmospheric corrosion rate respectively for each time of exposure during one year of study. Monthly average values of relative humidity, temperature, and wind were obtained from a meteorological station located near the study zone. The results obtained from the typical description of the aggressive coastal environment of the atmosphere, and those demonstrated in terms of the monthly behavior of corrosion rate and the influencing factors, as well as the corrosivity categories of the atmosphere determined at different distances from the coastline, can be taken as criteria for durability, before proceeding with the design, construction, maintenance, and repair of structures in the coastal study zone. A difference between the two variants of corrosivity of the atmosphere evaluation, that it to say, between the estimation from the typical description of the aggressive coastal environment of the atmosphere in the study zone, and the determination using the annual average values of corrosion velocity, was demonstrated. This difference can also be taken as another criterion for durability in the study zone.