Effects of Temperature, Humidity, Nitrogen Dioxide and Nitric Acid Gases on Carbon-Steel, Galvanized, and Painted Steel

摘要

The objective of the study is to investigate the potential effect of nitrogen dioxide and nitric acid on carbon-steel, galvanized and painted steel under initial exposure conditions. The study attempts to measure initial rates of corrosion at realistically short times using surface electrode microcells that were developed to directly show the effects of damage without requiring wetted surfaces. Fourier transform infrared spectroscopy was used to identify surface corrosion products. Nitrogen dioxide is only a mild corrodant of steel and zinc under the conditions studied and caused no perceptible damage to the polyester/epoxy painted surfaces under the initial exposure conditions of the study. Nitric acid gas rapidly attacked both steel and zinc surfaces producing nitrate ions, nitrite ions, and for the zinc surface ammonium ions were also formed.