CORROSION OF MATERIALS IN SURFACE SEA WATER AFTER 6 MONTHS 

 OF EXPOSURE 



Technical Note N-1023 



YF 38.535.005.01.004 



By 



Fred M. Reinhart 



ABSTRACT 



A total of 880 specimens of 215 different alloys were completely 

 immersed in surface sea water for six months to obtain data for compari- 

 son with deep ocean corrosion data. 



Corrosion rates, types of corrosion, pit depths, and changes in 

 mechanical properties were determined. 



The highly alloyed nickel alloys, titanium alloys, silicon cast 

 irons, specialty stainless steels, columbium, tantalum and tantalum- 

 tungsten alloy were uncorroded both at the surface and at depth. 



The corrosion rates of the copper base alloys, nickel base alloys, 

 steels, and cast irons decreased as the concentration of oxygen in sea 

 water decreased . 



The copper base alloys, steels, cast irons, molybdenum, tungsten, 

 leads and lead-tin solder corroded uniformly. 



All the aluminum alloys were attacked by pitting and crevice 

 corrosion and sea water was more aggressive at depth than at the sur- 

 face. The effect of the oxygen concentration of sea water on the 

 corrosion of aluminum alloys was inconsistent. 



The stainless steels were attacked by crevice, pitting, edge and 

 tunnel corrosion except types 310, 317 and 329, 20Cb, 20Cb-3 and AM350 

 on which there was only incipient crevice corrosion. Crevice corrosion 

 was more severe in surface waters than at depth. 



This document has been approved for public release 

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