Assessment of Accelerated Corrosion Tests Compared to Beachfront Test and Proposed Evaluation Method

The results of a 7-year beachfront corrosion assessment compared to accelerated test performance will be presented. Statistical analysis shows that the performance of coating systems on a combination of aluminum alloys using a combination of standard corrosion tests and standard test durations correlates well with beachfront exposure of the same coating systems. The proposed assessment method minimizes false positives and negatives which may occur when using accelerated tests with a narrower selection of alloys and tests. In addition, data suggest that a one-year exposure at the beachfront test site used in this study may be sufficient to validate very long-term performance of coating systems. Data will be presented from coating systems exposed to ASTM B117, ASTM G85 Annex 4, GM9540P and beachfront at the Kennedy Space Center test site. Alloys include 2024-T3, 7075-T6, 5083-H131, and 2219-T87. Coating systems include a variety of chromate and non-chromate conversion coatings, primers from MIL-PRF-23377 Class C, MIL-PRF-85582 Class C and N, MIL-P-53022, MIL-P-53030 and topcoats from MIL-PRF-85285 and MIL-C-53039.