Accession Number : ADA330973

Title :   High Strength Alloys for Seawater Fastener Applications,

Corporate Author : NAVAL SURFACE WARFARE CENTER ANNAPOLIS MD

Personal Author(s) : Aylor, Denise M.

PDF Url : ADA330973

Report Date : 23 JUN 1994

Pagination or Media Count : 14

Abstract : Slow strain rate tests were conducted on Rene 41, Alloy 925, and Alloy A286. Specimens were evaluated in 3.5% NaCl solution in both freely corroding and cathodically polarized conditions and compared to similar specimens run in air. 5000 hour statically-loaded proving ring tests were also conducted in natural seawater under both freely corroding and cathodically polarized environments to assess the validity of the slow strain rate method in predicting long-term environmental cracking resistance. The proving ring tests were performed on Alloy K-500, Alloy 625 Plus, Alloy 625PH, Ti-6AI-4V ELI, and Beta C titanium. Slow strain rate results indicated good environmental cracking resistance for Alloy A286 in all environments evaluated. Rene 41 exhibited a hydrogen embrittlement susceptibility when polarized to -1000 and -1250 mV vs. SCE. Alloy 925 was susceptible to hydrogen embrittlement at -1250 mV and showed a reduced load bearing capacity in freely corroding, -850, and -1000 mV vs. SCE environments. The proving ring results showed that the slow strain rate method is valid for assessing long-term environmental cracking resistance of fastener alloys.

Descriptors :   *HIGH STRENGTH ALLOYS, *HYDROGEN EMBRITTLEMENT, *STRESS CORROSION, CRACKING(FRACTURING), STRAIN RATE, NICKEL ALLOYS, FASTENINGS, SEA WATER, TITANIUM ALLOYS.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE