Fractographic observations of cleavage initiation in the ductile-brittle transition region of a reactor-pressure-vessel steel

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02645567· OSTI ID:6648230

Rosenfield, A R; Shetty, D K; Skidmore, A J

This note reports the results of a fractographic study conducted on a group of 1T compact fracture toughness specimens of a heavy-section A508 steel denoted TSE6 tested in the ductile-brittle transition region (22 and 82/sup 0/C). The fatigue-precracked specimens were loaded at a rapid rate (760 or 550 mm per second) to promote cleavage-crack growth and lower-bound toughness behavior. All specimens experienced unstable cleavage fracture prior to reaching a maximum in the load displacement curve. Some ductile crack growth occurred in half of the specimens. The objective of fractographic examinations was to understand the observed statistical variations in cleavage initiation by (a) locating the origins of unstable cleavage fracture in the vicinity of the fatigue-precrack or ductilerupture crack fronts, (b) identifying microstructural features associated with the triggering of cleavage, and (c) documenting characteristic fracture surface dimensions such as the extent of stable-crack growth prior to unstable cleavage (..delta cap alpha..) and the distance of the cleavage origin from the ductilerupture front, /chi/ (or fatigue-crack front when ..delta cap alpha.. = 0).

• Research Organization: Battelle-Columbus Laboratories, Columbus, OH
• OSTI ID: 6648230
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 14A:9; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CLEAVAGE
CONTAINERS
CRACK PROPAGATION
CRYSTAL STRUCTURE
DESTRUCTIVE TESTING
DUCTILE-BRITTLE TRANSITIONS
FRACTOGRAPHY
FRACTURE PROPERTIES
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
POWER REACTORS
PRESSURE VESSELS
REACTORS
STEEL-ASTM-A508
STEELS
TESTING