Abstract View
Sea Spray Aerosol Assessment of Atmospheric Corrosion in a Marine Environment
RAYMOND SANTUCCI, Christine Sanders, US Naval Research Laboratory
Abstract Number: 37
Working Group: Aerosol Chemistry
Abstract
Marine atmospheric corrosion is facilitated by the deposition of salt-laden sea spray aerosols onto engineering materials. Aerosol deposition flux (mass / time-area) is clearly dependent upon atmospheric aerosol concentration (mass / volume) and deposition velocity (length / time), in accord with sample geometry and relevant fluid dynamics near the sample. A rigorous assessment of marine atmospheric corrosion at a controlled test site in Key West, Florida was conducted over the course of a year with the intent of elucidating the role of sea spray aerosols. Certain factors which have been previously implicated in the literature as controlling, or at least heavily influencing, the corrosion of engineering materials in atmospheric exposure were isolated and explored. In particular, the effect of sample geometry and orientation with respect to gravitational settling of sea spray aerosols, precipitation, and sea winds was explored. The effect of surface area on measured steel mass loss was explored to identify the veracity of the so-called “edge effect”. Efforts were made to correlate meteorological atmospheric conditions (Temperature, Relative Humidity, Wind Speed, Wind Direction, chloride deposition flux, etc.) to monthly assessments of corrosion damage. Interestingly, the summative, compounded monthly corrosion damage tends to significantly overshoot the observed cumulative corrosion damage for samples exposed over the same time period. The results of this study form the basis for new research regarding the role of sea spray aerosols in the marine atmospheric corrosion process. This “fresh look” into marine atmospheric corrosion and the way in which it is informed by the results of this research will be discussed. Future directions in the continued convergence between the fields of corrosion science and engineering and aerosol science and technology will be highlighted.