Reinhart 



report is devoted to the effects of these environments on the corrosion 

 of metals and alloys. 



A test site was considered to be suitable if the circulation, 

 sedimentation, and bottom conditions were representative of open ocean 

 conditions . 



A site meeting these requirements was selected at a nominal 

 depth of 6,000 feet. The location of this site in the Pacific Ocean 

 in relation to Port Hueneme and the Channel Islands is shown in 

 Figure' 1 as Submersible Test Units (STUs) 1-1, 1-2, 1-3, and 1-4. 



The complete oceanographic data for Site I are shown graphi- 

 cally in Figure 2. ' A portion of this data collected from 1961 

 to 1963 showed the presence of a minimum oxygen zone (as shown in 

 Figure 2) at depths between 2,000 and 3,000 feet. Oceanographic data 

 obtained at other sites also showed the presence of this minimum 

 oxygen zone regardless of depth to the ocean floor. 



Corrosion rates are affected by the concentration of oxygen 

 in the environment. Therefore, it was decided to establish a second 

 exposure site (STU II-l and II-2) at a nominal depth of 2,500 feet. 

 This site is also shown in Figure 1. 



The NCEL oceanographic investigations also disclosed that 

 the ocean floor at each of these sites was rather firm and was char- 

 acterized as sandy, green cohesive mud (partially glauconite) with 

 some rocks. 



This report presents and discusses the results obtained 

 from exposure of irons, steels, low alloy steels, alloy steels, 

 unalloyed and alloyed cast irons, steel wire ropes, anchor chains 

 and metallic coated products for six periods of time and at two 

 nominal depths. 



RESULTS AND DISCUSSION 



Dr. T. P. May, Manager, Harbor Island Corrosion Laboratory 

 of the International Nickel Company, Inc. has granted permission to 

 incorporate his corrosion data (Reference 4), obtained from their 

 specimens on the six STU structures, with the NCEL data. 



Surface data of some alloys from the Atlantic Ocean 

 (Reference 5) and similar to those from the Panama Canal Zone, 

 Pacific Ocean (Reference 6) are included for comparison purposes. 

 Deep ocean data from the Atlantic Ocean is also included to permit 

 comparison of the different deep ocean environments. References 7, 

 8, and 9. 



The corrosion rates of all the alloys are shown graphically 

 in Figure 3 . 



Water in the open sea is quite uniform in its composition 

 ■throughout the oceans; therefore, the corrosion rates of steels 

 exposed under similar conditions in clean sea water should be com- 

 parable. The results of many investigations on the corrosion of 

 structural steels in surface sea water at many locations throughout 

 the world show that after a short period of exposure the corrosion 

 rates are constant and amount to between 3 and 5 mils per year. ' ' 

 Factors which may cause differences in corrosion rates outside these 



266 



