A chloride deposition model for predicting the categories of atmospheric corrosivity in coastal areas

Background: Marine atmospheres are the most corrosive, primarily because they contain sea salts. To assess the category of atmospheric corrosivity, the deposition rate of chloride ions should be measured by experimental methods for at least 1 year, which requires significant expenses and is not always feasible due to the time frame required for the design and erection of structures. Methods: In this study, a fairly simple model for predicting the chloride deposition rate in the coastal zone depending on the wind pattern of the test site, namely wind direction, average speed, and duration in each wind speed range, the distance from the coastline, and the magnitude of marine aerosol generation for each wind speed range, has been developed. The results of comparing the calculated chloride deposition rates with experimental data obtained by the ‘wet candle’ method are presented. Significant findings: The applicability of the model for predicting the categories of atmospheric corrosivity toward typical metals (carbon steel, zinc, copper and aluminum) using dose-response functions has been demonstrated.