which was 100 percent rusted on the outer surfaces to considerable 

 remaining on the 0.25 inch diameter, 7 x 19 construction cable 

 which was dark gray. There was no loss in the breaking strength 

 of any of these five cables. 



After 403 days of exposure at a depth of 6,780 feet the smaller 

 diameter (0„094, 0.125 and C.187 inch diameter) stainless steel 

 cables lost considerable strength, 90, 86, and 96 percent respectively. 

 These decreases were all attributed to crevice corrosion of the 

 internal wires. Many pits were also found on the individual wires 

 away from the breaks and some broken ends were protruding from the 

 cables prior to testing. 



There was no loss in breaking strength of the three larger 

 diameter stainless steel cables, the inside strands were chiefly 

 metallic color with only a few localized rust spots. 



Two types 304 stainless steel cables clad with a 90 percent 

 copper-10 nickel alloy were exposed for 402 days at a depth of 2,370 

 feet. One cable, 1 x 37 x 7 construction with a 0.3 mil thick clad 

 layer was covered with rust on the outside but the inside wires 

 were uncorroded. The other cable, 7x7 construction with a clad 

 layer 0,7 mil thick was covered with green corrosion products on the 

 outside, uncorroded on the inside strands and had lost no strength. 



Three aluminized steel cables (7x7, 1 x 19 and 1 x 19 construc- 

 tion) with 0„6, 0.6 and 0,7 mil thick coatings lost no strength 

 during the 402 day exposure at a depth of 2,370 feet. The 7x7, 

 0.187 inch diameter cable was covered with white corrosion products 

 and a few light rust stains but the inside strands were dull gray in 

 color. The outside surfaces of the 1 x 19 construction wires (0.250 

 and 0.313 inch diameter) were gray in color with scattered white 

 corrosion products covering about 50 percent of the surfaces. The 

 inside strands were a dull gray color. 



Eight wire ropes were stressed in tension equivalent to approxi- 

 mately 20 percent of their respective original breaking strengths 

 as shown in Table 10. There were no stress corrosion failures after 

 either 751 or 1,064 days of exposure. However, the breaking strength 

 of the Type 316 wire rope lost 40 percent of its strength after 1,064 

 days of exposure at a depth of 5,300 feet because of crevice corro- 

 sion of the internal wires. The breaking strength of the galvanized 

 plow steel (0.83 oz Zn) was decreased by 17 percent. The breaking 

 strengths of the other six wire ropes were unaffected. Although 

 there was no loss in the breaking strength of the 18 percent chromium- 14 

 percent manganese stainless steel rope there were quite a number of 

 broken wires due to corrosion both on the outside and on the inside 

 strands. 



10 



