Lawson Foundation

If a plane should crash and the passengers all survive, some of them will tell you that when they got on the plane they ‘knew’ it was going to crash and the media will portray them as clairvoyants. What they probably won’t …

In 1976, the ASTM G01.04 Subcommittee on Atmospheric Corrosion initiated a long-term atmospheric corrosion test program at five outdoor locations: Kure Beach, NC (25-meter East-coast marine), Newark-Kearney, NJ (industrial), State College, PA (rural), Point Reyes, CA (West-coast marine), and Fort Sherman, Panama (tropical marine). Among the forty-one materials exposed were four coated steel sheet products: G60 galvanized, G90 galvanized, 55% aluminum-zinc-coated, and Type 2 aluminum-coated. Results are presented for the performance of the coated sheet steels after 21 years. These results indicate the following qualitative order of corrosivity for five sites: Panama ~ Kure Beach > Newark-Kearny > State College > Point Reyes Based on changes in the corrosion of 55% aluminum-zinc-coated, an increase in the aggressiveness at Panama took place sometime during the 10th to 21st year of exposure. Future testing at these sites could be better quantified by short-term (1–2 years) exposures of standard materials. A loss of significant data from 2-, 5- and 10-year removals and initial weights for many of the test materials highlights the importance of safeguards to ensure the integrity of future long-term ASTM tests. In terms of relative performance, the results are consistent with the following order of corrosion resistance (most-to-least). T2 100 ~ AZ55 > G90 > G60