Aerated total immersion corrosion test

D 1374 1989 Method for aerated total immersion corrosion test for metal cleaners... 

Maconachie (1934) noted that Cox s results applied only to a 15-day test and did not define the influence of duration of exposure within this time. Maconachie immersed 99.99% zinc specimens in distilled water aerated by movement of the test assembly for 7 days at temperatures of SO-SO C. Weight losses were determined on specimens removed at daily intervals. At 20°C the distilled water had a pH of 5.2, largely as a result of dissolved carbon dioxide. At the higher test temperatures, however, the pH was probably higher as the carbon dioxide was expelled from the solution. The total corrosion as a function of temperature is shown at daily intervals in Fig. 3.4. The general shapes of the curves resemble those reported by Cox (1931) for 15 days and... 

Alternate Immersion in 3.5% NoCl. Exposure to 3.5% sodium chloride or to substitute ocean water (ASTM D 1141) by alternate immosion (ASTM G 44) (see Table 1) is a widely used procedure for testing smooth specimens of aluminum alloys. Aeration of the specimens, achieved by the alternate immersion, enhances the corrosion potential (Ref 26) and produces more rapid SCC of most aluminum alloys than continuous immersion. The ASTM G 44 standard practice consists of a 1 h cycle that includes a 10 min soak in the aqueous solution followed by a SO min period out of solution in air at 27 °C (80 °F) and 45% relative humidity, during which time the specimens are air dried, lliis 1 h cycle is repeated continuously for the total number of days recommended for the particular alloy being tested. IVpically, aluminum alloys are exposed from 10 to 90 days, depending on the resistance of the alloy to corrosion by salt water. This test ntethod is widely used for testing most types of aluminum alloys with all types of smooth specimens. 

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