Accession Number:

ADA190252

Title:

Investigation of the Stress Corrosion Cracking Susceptibility of Annealed and Heat Treated Alloy 625 Castings and Forgings in Sea Water

Descriptive Note:

Master's thesis

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF OCEAN ENGINEERING

Personal Author(s):

Report Date:

1987-06-01

Pagination or Media Count:

105.0

Abstract:

Alloy 625, the nickel based superalloy commonly called Inconel 625, was investigated for its susceptibility to stress corrosion cracking in sea water using the slow strain rate tensile test method. Four microstructures of the alloy commonly found in end products were investigated. Bimetallic couplings with other metals were simulated with a potentiostat at plus and minus one volt with respect to a saturated standard calomel electrode SCE. Baseline tests were conducted in air and sea water without applied potential. The response of the alloy to cathodic protection of minus three volt SCE was also investigated on the two most commonly used microstructures, as cast and forgedannealed. The different microstructures developed were characterized with a scanning electron microscope SEM. The gage lengths, fracture surfaces, and sections of test specimens were also examined with a SEM. The data from the slow strain rate tensile tests were compared with data from standard tensile tests performed on the same processed material.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE