b. Ni-Cr-Mo #3 



c. Ni-Gr-Mo 625 



d . Ni-Co-Cr 700 except for 3 specimens with incipient crevice 



corrosion 



e. Ni-Cr-Fe-Mo F 



f. Ni-Cr-Fe-Mo G 



g. Ni-Cr-Fe-Mo X except for 1 specimen with incipient crevice 



corrosion 



h. Ni-Cr-Co 41 



i. Ni-Mo-Cr C 



The U. S. Navy Marine Engineering Laboratory also reported no visible 

 corrosion on nickel-molybdenum-chromium alloy C at depth in the 



' o 



Pacific Ocean. 

 Nickel-Chromium-Iron Alloys 



Alloys 600, cast 610, X750 and 88 were attacked chiefly by the 

 crevice type of corrosion with some pitting in a few specimens (see 

 Table 9) both in the sea water and when partially embedded in the 

 bottom sediments. Generally, the crevice corrosion was less severe 

 on the specimens partially embedded in the bottom sediments than on 

 the specimens totally exposed in the sea water. 



When alloy 600 was welded with electrodes 132, 62 and 82 the 

 weld bead materials were selectively attacked and were perforated 

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

 feet. In addition, there was line corrosion along the edges of the 

 weld beads made from electrodes 62 and 82 „ Also, there was severe 

 tunneling corrosion to perforation in the heat-affected zone of 

 alloy 600 adjacent to the weld bead made with electrode 82 as shown 

 in Figure 10„ The line corrosion and selective attack of the weld 

 beads indicates that the weld bead materials were anodic to the 

 parent sheet material (alloy 600). However, when alloy 600 was weld- 

 ed with electrode 182 the only observable corrosion after 402 days 

 of exposure in the sea water at a depth of 2,370 feet was a slight 



