Evaluation of SCC test methods for Inconel 600 in low-temperature aqueous solutions

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Am. Soc. Test. Mater., Spec. Tech. Publ.; (United States)

DOI:https://doi.org/10.1520/STP34440S· OSTI ID:6180421

Newman, R C; Roberge, R; Bandy, R

In late 1981, widespread leakage was encountered in Alloy 66 steam generator tubing at the Three Mile Island Unit 1 nuclear power plant. The phenomenon was identified as low-temperature intergranular stress-corrosion cracking (SCC) initiated from the inner surfaces of the tubes exposed to the primary coolant. A testing program was initiated to examine the material and environmental factors relevant to these failures, which were found to be associated with sensitization of the material and contamination of the coolant by air and sodium thiosulfate. The test solutions contained 1.3% boric acid with various additions of sulfur compounds and lithium hydroxide. Constant extension rate testing was used as the primary tool to examine environmental effects such as the inhibition of cracking by lithium hydroxide. Important effects of crack initiation, and the effects of further environmental additions were monitored by following the load decay at constant total strain. This procedure generally resulted in a different ranking of the environments. U-bend tests showed that the ranking of different sulfur-containing environments was also highly dependent on the metal heat treatment.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 6180421
• Journal Information: Am. Soc. Test. Mater., Spec. Tech. Publ.; (United States), Journal Name: Am. Soc. Test. Mater., Spec. Tech. Publ.; (United States) Vol. 821; ISSN ASTTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
AQUEOUS SOLUTIONS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CORROSION
CRACK PROPAGATION
DATA
DISPERSIONS
EXPERIMENTAL DATA
INCONEL 600
INCONEL ALLOYS
INFORMATION
IRON ALLOYS
LOW TEMPERATURE
MIXTURES
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
NUMERICAL DATA
SOLUTIONS
STRESS CORROSION