EXCO test ASTM

FIG. 2—Influence of environmental conditions on the exfoliation corrosion of a material with a low resistance to exfoliation. AA2124-T351 rolled 51-mm thick plate rated ED In the standard EXCO test, ASTM G 34 [2]. 

G34-99, Standard test method for exfoliation corrosion susceptibility in 2XXX and 7XXX series aluminum alloys EXCO test. Annual Book of ASTM Standards, ASTM International, Philadelphia, Pa., 2000, p. 124, Vol. 3.02. 

Lee, S. and Lifka, B. W., Modification of the EXCO Test Method for Exfoliation Corrosion Susceptibility in 7XXX, 2XXX and Aluminirm-Lithium Alloys, Afew Methods for Corrosion Testing of Aluminum Alloys, ASTM STP 1134, V. S. Agarwala and G. M. Ugiansky, Eds., ASTM International, West Conshohocken, PA, 1992, pp. 1-19. 

The history of airplane corrosion testing includes many successful tests that are now performed routinely, e.g., ASTM G 85 Annex A2 and ASTM G 44. Some other successful tests, such as the wedge test (ASTM D 3762, Test Method for Adhesive-Bonded Surface Durability of Aluminum), discovered as a result of bond line corrosion problems on airplanes, are not described here because they are not strictly corrosion tests. Many of the tests described here are ASTM standards. With others, standardization is being pursued, e.g., electrochemical impedance, or ANCIT (Aluminum-Nitrate Chloride Immersion Test), to replace EXCO [4], Corrosion may never be totally eliminated from an airplane however, further refinements in corrosion testing, made... 

ASTM G34 - test method for exfoliation corrosion susceptibility in 2xxx and 7xxx series aluminum alloys (EXCO Test). 

S. Lee and B.W. Lifka, Modification of the EXCO Test Method for Exfoliation Coirasion Susceptibility in Ixxx, 2xxx and Aluminum-Lithium Alloys, New Methods for Corrosion Testing Aluminum Alloys, V.S. Agarwala and GA1. Ugiansky, Ed, ASTM, 1992, p 1-19... 

Lifka, B. W. and Lee, S., Exfoliation Test Results on 2519-T87 Plate Disparity of Results in EXCO Versus Other Envi-rorrments, Presentation of ASTM Subcommittee GO 1.05 Workshop on Exfoliation Corrosion, 1988. 

Three laboratory tests for exfciiation corrositHi testing were perfonned representing two approaches to testing. The first approach emphasizes simplicity and bottom line results—-the EXCO immersion test The second approach attempts to reproduce the envinm-mental factors contributing to corrosivity and materials behavior—represented by the SO2 salt fog test and MASTMAASIS salt fog test Characteristics of these test environments are shown in Thble 3. Neutral salt fog conditions (ASTM B 117) and outdoor exposure (service) conditions are givm fm comparison. 

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