Corporate Engineering, Air Products and Chemicals, Inc., Allentown, PA
Pages: 27 Published: Jan 1995
The USA part of ISO CORRAG Collaborative Atmospheric Exposure Program has completed 4 years. The purpose of this worldwide exposure program has been to obtain atmospheric and corrosion data on four metals to verify that the atmospheric classification system given in ISO standards ISO 9223, 9224, 9225, and 9226 are valid. Five sites were included in this program; 250 m lot at Kure Beach, Newark-Kearny, Point Reyes, Los Angeles, and the Fort Sherman coastal site in Panama. Flat panels and wire helices were used with triplicate specimens for six consecutive 1 year and single 2, 4 and 8 year exposures. The helices appear to corrode at significantly higher rates than the panels. The Fort Sherman coastal site was most corrosive to all alloys. The Newark Kearny site exhibited significantly lower corrosivity than in previous exposures. Multiple regression analyses showed that the environmental data accounted for a major portion of the variation in corrosion data for all metals except aluminum. The ISO classification system was accurate in 58% of the cases studied. In the other cases, it underestimated the corrosion rate about as often as it over-estimated the rate.
atmospheric corrosion, time of wetness, sulfation plate, classification of atmospheres, chloride candle, multiple linear regression analysis
Paper ID: STP14913S