Accession Number:

AD0466955

Title:

EVALUATION OF METALLIC MATERIALS EXPOSED TO THE DEEP OCEAN ENVIRONMENT AT 5640 FEET FOR 123 DAYS,

Descriptive Note:

Corporate Author:

NAVAL AIR ENGINEERING CENTER LAKEHURST NJ AERONAUTICAL MATERIALS LAB

Personal Author(s):

Report Date:

1965-06-22

Pagination or Media Count:

1.0

Abstract:

Over 200 metallic specimens of 30 different compositions attached to submersible test unit I-3 exposed to the deep ocean environment at 5640 ft. approximately 31 nautical miles west of Port Hueneme, California, for a period of ays have been evaluated for deteriorative effects. Specimens were exposed in the following conditions 9a heat treated b welded c painted d stressed and e coupled. Corrosion rates were calculated for those metals exhibiting uniform general attack such as the alloy steels, stainless steels and copper base alloys. Those metals undergoing selective corrosion such as pitting of certain aluminum alloys were evaluated for the frequency and severity of attack. Certain high strength steels and stainless steels exposed at stress levels below their yield strengths were metallographically examined for evidences of microstructural attack andor stress corrosion cracking. No evidence of either phenomenon were found in the specimens in question. Severe macroscopic crater type pitting was disclosed in 5456-H34 aluminum alloy. An increase, over shallow depth exposures, in the severity of intergranular attack and exfoliation attack is noted in the appropriately susceptible tempers of the 2000 and 7000 series aluminum alloys, in both the welded and non-welded conditions. The mechanical properties of the exposed metals are compared with the unexposed control specimens in order to obtain percent reduction in strength data. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE