Humid air corrosion of carbon steel under conditions of constant temperature and relative humidity was investigated. Carbon steel is a candidate material for the Yucca Mountain Site Characterization Project’s Waste Packages (WP). The WPs are containers for storage of high level nuclear waste at a potential repository at Yucca Mountain, Nevada. A thermogravimetric analyzer was employed to investigate the short term corrosion of carbon steel under constant relative humidities, at elevated temperatures (60-90°C), and with various surface conditions. As expected, the initial corrosion rates are greatly enhanced by the presence of deposited sodium chloride under high relative humidity conditions. The corrosion product formed with deposited sodium chloride is porous and
non-adherent. However, the corrosion rate decreases with time; this suggests that the components of the deposited salt are incorporated into the corrosion products. Characterization of the corrosion product formed gave an understanding of the long term corrosion processes.
Keywords: atmospheric corrosion, carbon steel, humid air corrosion, sodium chloride, NaCI, relative humidity