The most important factor influencing the corrosion of steels in 



seawater is the dissolved oxygen content. The change in concentration of 



21 

 oxygen in seawater with depth is shown in Figure 3 for two specific 



locations in the Atlantic and Pacific Oceans. It illustrates the require- 

 ment for data on the actual oxygen concentration at the desired depth for 

 a specific location of interest. Reinhart ' and Wheatfall showed that, 

 at depths where dissolved oxygen concentrations varied, the rate of corro- 

 sion of steels was closely related to the concentration of dissolved 



21 

 oxygen. This is illustrated in Figure 4 for carbon and low-alloy steels 



exposed for 1 yr in the Pacific Ocean. Also in deep waters with lower 



oxygen content, the morphology of attack on steel is more uniform and less 



rough than at the surface. 



24 



g 4000 h 



5000 - 



6000 - 



7000 



1 



12 3 4 



OXYGEN (mM) 



Figure 3 - Change in Concentration of 

 Oxygen in Seawater with Depth 



12 



