The austenitic cast irons also corroded uniformly, similar to the 
steels. 
There was incipient crevice corrosion of AISI Type 316 stainless 
steel tubing at the junctions with the fittings. Zinc anodes prevented 
this type of corrosion. 
Stainless steel 20Cb-3 was attacked by severe crevice corrosion in 
the bottom sediment and by incipient crevice and pitting corrosion in 
seawater. 
An aluminum coating (1 oz/£t*) on steel was about 50 percent con- 
sumed while the zinc coating (1 oz/f£t*) was completely consumed and the 
steel was rusting, indicating that an aluminum coating will provide 
longer protection to steel than will a zinc coating of the same weight 
(1 oz/ft2). 
The two precipitation hardened stainless steels, heat treated, un- 
welded and welded, were attacked by pinpoint pitting and incipient 
erevice corrosion except for deep pits localized in the weld bead of 
steel 362 in the H1050 condition. Paint coatings offered good protec- 
tion except for a zinc rich primer alone. 
Paint coatings 4 and 5, Table 8, protected three high strength- 
low alloy steels while the zinc rich primer alone permitted penetration 
of seawater and subsequent rusting. 
Titanium Alloys 
The titanium alloys, like previously exposed alloys, did not cor- 
rode except for stress corrosion cracking of titanium alloy 13V-11Cr- 
3A1, which had been welded with a 3-inch diameter circular weld bead 
and not subsequently stress relief annealed. 
Stress Corrosion 
An 18 percent Ni maraging steel was susceptible to stress corro- 
sion cracking when stressed at 50 and 75 percent of its yield strength. 
Two aluminum alloys, a high strength-low alloy steel, two high strength 
steels, two precipitation hardening stainless steels and seven titanium 
alloys were immune to stress corrosion cracking. 
Wire Ropes 
A 0.5 oz/ft2 zinc coating protected steel wire rope for approxi- 
mately 6 months. 
Polyurethane and polyethylene sheaths provided good protection to 
zinc coated wire rope except at the terminals which leaked, permitting 
seawater to penetrate between the sheathing and the rope. 
AISI Type 304 stainless steel wire ropes, unrelieved and stress 
relieved, were severely attacked by pitting, tunneling and crevice 
