skip to main content

Title: Phase stability and mechanical properties of C-22 alloy aged in the temperature range 590 to 760 C for 16,000 hours

The phase stability of C-22 alloy (UNS No. N06022) was studied by aging samples at 593, 649, 704 and 760 C for 2,000 h (2.7 mo) and 16,000 h (1.8 yr). The tensile properties and the Charpy impact toughness of these samples were measured in the mill annealed condition as well as after aging. The microstructures of samples aged 16,000 hours were examined using scanning and transmission electron microscopy (SEM and TEM). Preliminary TEM results suggest that {mu} phase forms at all temperatures investigated. Discrete carbide particles in addition to a film with very uniform thickness which appears to be {mu} phase formed on grain boundaries in the sample aged at 593 C. The ordered Ni{sub 2}(Cr, Mo) phase was also seen in this sample. At the higher aging temperatures, mainly {mu} phase forms covering all the grain boundaries and also distributed throughout the bulk. Although strength increased somewhat with aging, the ductility decreased due to the formation of these grain boundary precipitates and brittle intermetallics.
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
20015847
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: 1998 Materials Research Society Fall Meeting, Boston, MA (US), 11/30/1998--12/04/1998; Other Information: Single article reprints are available from University Microfilms Inc., 300 North Zeeb Road, Ann Arbor, Michigan 48106; PBD: 1999; Related Information: In: Scientific basis for nuclear waste management XXII. Materials Research Society symposium proceedings: Volume 556, by Wronkiewicz, D.J.; Lee, J.H. [eds.], 1355 pages.
Publisher:
Materials Research Society, Warrendale, PA (US)
Research Org:
Lawrence Livermore National Lab., CA (US)
Sponsoring Org:
US Department of Energy
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; HASTELLOYS; PHASE STUDIES; MICROSTRUCTURE; ULTIMATE STRENGTH; YIELD STRENGTH; ELONGATION; CHARPY TEST; RADIOACTIVE WASTE DISPOSAL; CONTAINERS