Manager, Technical Services, American Hot Dip Galvanizers Association, Inc., Washington, D.C.,
Pages: 23 Published: Jan 1982
Results of an ASTM-sponsored 20-year exposure of corrugated metallic-coated steel panels at five locations in the United States are reported. A total of 19 panels was placed at each exposure site, including at least one specimen from each of six types of continuous galvanizing lines in use when the test was initiated, five sheets galvanized using equipment similar to that used to prepare specimens for a similar test series initiated in 1926, one panel coated with pure aluminum, one panel coated with an aluminum-silicon alloy, and one panel coated with terne metal.
The analysis of the galvanized coatings data suggests the presence of nonlinear effects in the performance of the coatings. However, it was not possible to establish whether these effects were the result of nonlinearities in the coating performance itself or if they were the consequence of uncontrollable external factors which occurred during the exposure period.
The aluminized sheets were found to be essentially without failure at all test locations. In general, coating degradation beyond minor pinholing was not found.
The terne-coated sheets evidenced early rusting at all except the most aggressive of the test sites. Despite nearly total coating depletion, none of the test sheets have perforated.
aluminized coatings, ASTM atmospheric test sites, atmospheric performance, corrosion, hot dip galvanized coatings, industrial atmospheres, metallic coatings, rural atmospheres, terne coatings
Paper ID: STP33192S