Stress Corrosion 
A number of the alloys were stressed in tension at stresses equiva- 
lent to 50 or 75 percent of their respective yield strengths to deter- 
mine their susceptibility to stress corrosion cracking. These alloys, 
the levels of stress, and their susceptibility to stress corrosion 
cracking, both in the seawater and when partially embedded in the bottom 
sediments, are given in Tablell. 
Only the 18 percent Ni maraging steel failed by stress corrosion 
cracking at 75 percent of its yield strength in seawater and at both 
50 and 75 percent of its yield strength when partially embedded in the 
bottom sediments. 
The other alloys, two aluminum alloys, a high strength-low alloy 
steel, two high strength steels, two precipitation hardening steels, 
and seven titanium alloys were immune to stress corrosion cracking in 
these environments for 189 days of exposure at a depth of 5,900 feet. 
Wire Ropes 
A number of wire ropes of different compositions were exposed. 
These wire ropes and their corrosion behavior are given in Table 12. 
The zine coating on the 0.250-inch diameter wire rope was com- 
pletely gone with heavy rust in some grooves while the same weight of 
zine coating (0.5 oz per sq ft) on the 0.500-inch diameter, same con- 
struction (3 x 19), was not completely gone and there was more zinc 
remaining on the 0.500-inch diameter, 3 x 7 construction wire rope. 
The reason for some zinc remaining on the 0.500-inch diameter ropes is 
that there is less surface area of steel for the zinc to protect than 
on the 0.250-inch diameter rope. 
The polyurethane and polyethylene sheaths protected the zinc 
coated wires to a considerable extent. The sheaths were not punctured 
or broken, but seawater had penetrated to the metal ropes through the 
end terminations. That water had penetrated to the interface between 
the sheath and the rope was proven by puncturing the sheath, at which 
time seawater spurted out under considerable pressure. When a termi- 
nal on one end of each specimen was removed, the zinc coatings on the 
portions of the ropes which were inside the terminals were gone and 
the wires were rusted, chiefly on the ends of the ropes. The poly- 
ethylene sheath on one specimen had been punctured in many places prior 
to exposure. After exposure these holes were filled with white corro- 
sion products, but there was no rust on the rope except inside the 
terminals on the ends. 
Type 304 stainless steel wire ropes, whether or not they were 
stress relieved, corroded by pitting, tunneling and crevice corrosion 
which were more severe on internal wires. There were no broken wires 
in one 3 x 7 construction rope, but many broken wires on the 3 x 19 
construction ropes. The addition of vanadium and nitrogen to the Type 
