Atmospheric Corrosivity Map for Management of Steel Infrastructure in India Using ISO Dose–Response Function and Gridded Data

Abstract

The first-year corrosion rate (K) values of metals measured using standard protocols are indicative of the relative vulnerability of metal infrastructure to atmospheric corrosion at a given location. The Dose–Response Functions (DRFs) given by ISO can be used to estimate K for steel, zinc, aluminum, and copper if data for temperature, relative humidity, sulfur dioxide, and chloride deposition rates are available. This paper evaluates the efficiency of the ISO DRFs as a classification tool for atmospheric corrosivity in India. The best performing DRF was found to be that for steel and was subsequently combined with gridded datasets of 1°×1° (latitude×longitude) resolution to develop a spatially continuous corrosivity map for steel infrastructure in India. A gridded sulfur dioxide dataset was specifically constituted and used in conjunction with duly validated gridded meteorological records to develop the map. The map reveals that 10% of the Indian mainland has very strong corrosivity, and many grids classified under low and moderate categories exhibit increasing trends. The gridded time of wetness map shows fair conformity to the corrosivity trends.