After 402 days of exposure in sea water at a depth of 2,370 

 feet, there was end penetration of the weld bead material when alloy 

 800 was welded with electrode 82 and line corrosion along the weld 

 bead when alloy 800 was welded with electrode 138. The line corro- 

 sion along the weld bead is indicative of the presence of a line of 

 anodic material along the weld bead. 



Nickel-Molybdenum- Iron Alloy B 



Alloy B was corroded uniformly except for a groove about 4 mils 

 deep at the mud line after 403 days at a depth of 6,780 feet and for 

 incipient crevice and pitting corrosion in the bottom sediment after 

 197 days at a depth of 2,340 feet. 



The corrosion rates of alloy B are shown in Figure 11. At the 

 5,500 foot depth in the sea water the corrosion rate increased 

 sharply between 123 and 403 days of exposure and decreased gradually 

 thereafter with increasing duration of exposure. In the bottom 

 sediment at a depth of 5,500 feet, there was generally a decrease 

 in the corrosion rate with increasing duration of exposure and the 

 corrosion rate was lower than in the sea water. The corrosion 

 rates at the 2,350 foot depth increased between 200 and 400 days 

 of exposure the increase being greater in the sea water than in 

 the bottom sediment. 



Nickel-Tin-Zinc Alloy 23 



Alloy 23 was susceptible to severe crevice corrosion (56 mils 

 in 751 days) and to pitting corrosion (35 mils in 1064 days). 



Nickel-Beryllium Alloy 



The nickel-beryllium alloy specimens were in the form of bars 

 0.94 inch diameter which were pitted on the ends to depths of 17 

 mils in the sea water and 8 mils in the bottom sediment. The cor- 

 rosion rate in the sea water was greater than that in the bottom 

 sediment . 



Nickel-Chromium Alloys 



Alloys 65-35, 75 and 80-20 were attacked by crevice corrosion 

 which varied in severity from incipient to perforation (50 mils) 

 both in the sea water and in the bottom sediment. The corrosion 



