Unclassified 



Security Classification 



fSu 



DOCUMENT CONTROL DATA - R&D 



o/ title, body ot abstract Bnd indexing annotation must be entered when the overall report ia classified) 



1 ORIGINATIN G ACTIUITY (Corporate author) 



U. S. Naval Civil Engineering Laboratory 

 Port Hueneme, California 93041 



a. REPORT SECURITY CLASSIFICATION 



Unclassified 



3 REPORT TITLE 



CORROSION OF MATERIALS IN HYDROSPACE - PART I. IRONS, STEELS, CAST IRONS, 

 AND STEEL PRODUCTS 



4 DESCRIPTIVE NOTES (Type ot report and inclusive dales) 



S AUTHORfS; (Last name, lirst i 



Reinhart, Fred M. 



6 REPORT DATE 



July 1967 



la TOTAL NO. OF PASES 



71 



76 NO. OF REFS 



34 



8a. CONTRACT OR GRAN 



6. PROJECT NO. Y-F015-01-05-002A 



■*• Doar. J^^ P^..>L-oog^ 



9a ORIGINATOR'S REPORT NUMBERfS; 



N-900 



9b. OTHER REPORT HO(S) (Any other numberm that may be mmaignati 



n. SUPPLEMENTARY NOTES 



Internal Working Paper 



12. SPONSORING MILITARY ACTIVITY 



Naval Facilities Engineering Command 

 Washington, D. C. 20390 



13. ABSTRACT 



A total of 1300 specimens of 47 iron base alloys were exposed at depths of 

 2,340, 2,370, 5,300, 5,640 and 6,780 feet at two sites in the Pacific Ocean for 197, 

 402, 1064, 123, 751 and 403 days respectively to determine the effects of deep ocean 

 environments on their corrosion behavior. 



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

 properties, effects of stress, and analyses of corrosion products are presented. 



The corrosion rates of all the alloys, both cast and wrought, decreased 

 asymptotically with duration of exposure and became constant at rates varying 

 between 0.5 and 1.0 mils per year after three years ef exposure in sea water and 

 partially embedded in the bottom sediments at a nominal depth of 5,500 feet. These 

 corrosion rates are about one-third those at the surface in the Atlantic Ocean. 



At the 2,350 foot depth, the corrosion rates in sea water also decreased with 

 duration of exposure but tended to increase slightly with duration of exposure in 

 the bottom sediments. 



The corrosion rates at the 2,350 foot depth were less than those at the 

 5,500 foot depth. 



The mechanical properties were unimpaired. 



Silicon and silicon-molybdenum cast irons were uncorroded. 



A sprayed 6 mil thick coating of aluminum protected steel for a minimum of 

 three years and a hot dipped 4 mil thick coating of aluminum protected steel for a 

 minimum of 13 months while a hot dipped 1.7 mil thick coating of zinc protected 

 steel for about 4 months. 



DD /.?S^ 1473 



0101-807-6800 



Unclassified 



Security Classification 



