Creep and fracture of a laves phase strengthened ferritic alloy

Journal Article · Sat May 01 04:00:00 EDT 1976 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF03186808· OSTI ID:7228057

Bhandarkar, M D; Bhat, M S; Parker, E R; Zackay, V F

The microstructural changes which occurred during creep were examined in a carbon-free ferritic alloy containing 1 at.percent Ta and 7 at. percent Cr. The alloy derived its creep resistance from a uniform dispersion of almost spherical particles of the Laves phase Fe/sub 2/Ta in a bcc matrix. There was a lath-like substructure in this alloy, with dislocation tangles and subgrains within the laths. Partial recovery during creep led to the formation of a regular subgrain structure. The Laves phase particles prevented total recovery by pinning individual dislocations and subgrain boundaries. The apparent activation energy for creep, the estimated stress sensitivity of minimum creep rate, and the substructural features observed in crept specimens suggested that creep deformation of the alloy occurred by two or more independent processes. Fracture under creep conditions was initiated by void formation at precipitate-matrix interfaces. Intergranular void formation played an important role in the fracture of creep specimens tested at 1200/sup 0/F, but not at lower temperatures.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 7228057
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 7; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHROMIUM ALLOYS
CHROMIUM STEELS
CREEP
CRYSTAL STRUCTURE
DISPERSION HARDENING
FRACTURE PROPERTIES
HARDENING
IRON ALLOYS
IRON BASE ALLOYS
LAVES PHASES
MECHANICAL PROPERTIES
MICROSTRUCTURE
STEELS
TANTALUM ADDITIONS
TANTALUM ALLOYS
YIELD STRENGTH