INTRODUCTION 



The development of deep diving submarines which can stay sub- 

 merged for long periods of time has focused attention on the deep 

 ocean as an operating environment. This has created a need for 

 information about the behavior of common materials of construction 

 as well as newly developed materials with promising potentials, at 

 depths in the ocean. 



To study the problems of construction in the deep ocean, project 

 "Deep Ocean Studies" was established. Fundamental to the design, 

 construction and operation of structures, and their related facilities 

 is information about the deterioration of materials in these deep 

 ocean environments. This report is devoted to the portion of the 

 project concerned with determining the effects of these environments 

 on the corrosion of metals and alloys. 



The test sites for the deep ocean exposures are shown in Figure 

 1 and their specific geographical locations are given in Table 1. 

 The complete oceanographic data at these sites obtained during NCEL 

 cruises from 1961 to 1967 are summarized in Figure 2, Because of the 

 minimum- oxygen concentration zone found between the 2,000-3,000 foot 

 depths during the early oceanographic cruises, it was decided to 

 establish the second exposure site (STU II-l and II-2) at a nominal 

 depth of 2,500 feet, 



A summary of the characteristics of the bottom waters 10 feet 

 above the bottom sediments at the different exposure sites is given 

 in Table 1, 



Sources of information pertaining to the biological character- 

 istics of the bottom sediments, biological deterioration of materials, 

 detailed oceanographic data, and construction, emplacement and re- 

 trieval of STU structures are given in Reference 1, 



The procedures for the preparation of the specimens for exposure 

 and for evaluating them after exposure are described in Reference 2. 



Previous reports pertaining to the performance of materials in 

 the deep ocean environments are given in References 1 through 6. 



This report is a discussion of the corrosion of nickel and some 

 nickel alloys for the six exposure periods shown in Table 1, 



RESULTS AND DISCUSSIONS 



The results presented and discussed herein also include the 



