The excellent corrosion resistance of nickel-alloys has been put to good use in marine engineering for many years. Some applications, such as bolting, require high levels of strength as well as corrosion resistance. New high strength nickel-alloys and their weldments exhibit excellent resistance to hydrogen embrittlement and seawater corrosion. Solid solution nickel-based alloys such as alloy 686 (UNS N06686) obtain their strength through cold work. Other highly corrosion resistant nickel-alloys such as alloy 925 (UNS N09925) and alloy 725 (UNS N07725) are precipitation hardened. Both the cold worked and the precipitation hardened alloys exhibit exceptional strength, ductility and toughness.
Keywords: age-hardenable, solid solution, nickel-base alloys, seawater, pitting, crevice corrosion, fatigue resistance, bolting