An environmental cracking evaluation of fastener materials for seawater applications

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:82996

Aylor, D M ^[1]

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1. Naval Surface Warfare Center, Annapolis, MD (United States)

Slow strain rate tests (SSRT) were conducted on various nickel-base, titanium base, and copper-nickel (Cu-Ni) alloys in order to identify a replacement material for Alloy K-500 in seawater fastener applications. SSRT data and fracture surface analysis of the test specimens identified a susceptibility to environmental cracking in cathodically polarized environments for Alloy K-500, Alloy 625 Plus, and Alloy 625PH. Alloy 625 Plus exhibited slightly increased environmental cracking resistance-at {minus}850 mV vs. SCE over Alloy K-500 and Alloy 625PH. Ti-6Al-4V ELI, Beta C, and Beta 21S titanium displayed no susceptibility to environmental cracking in freely corroding 3.5% NaCl or cathodically polarized conditions. Precharging these titanium alloys for 8 weeks at {minus}1,250 mV vs. SCE did not adversely affect their environmental cracking resistance. The Cu-3Ni and Cu-15Ni-7Sn spray formed alloys exhibited extensive scatter and low measured maximum loads, presumably due to macroporosity present in the as-fabricated material.

• OSTI ID: 82996
• Report Number(s): CONF-940222--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ALUMINIUM ALLOYS
CATHODIC PROTECTION
COMPARATIVE EVALUATIONS
COPPER BASE ALLOYS
CORROSION RESISTANCE
CORROSIVE EFFECTS
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INCONEL 625
MATERIAL SUBSTITUTION
MECHANICAL TESTS
MONEL
NICKEL ALLOYS
NICKEL BASE ALLOYS
SEAWATER
TIN ALLOYS
TITANIUM BASE ALLOYS
VANADIUM ALLOYS