Micromechanisms of ductile stable crack growth in nuclear pressure vessel steels
The objective of this work was to investigate the relationship between the micromechanisms of ductile crack growth, the microstructural constituent phases present in nuclear pressure vessel steel, and the observed fracture behavior as determined by impact and fracture mechanics tests. Results from a microstructural and mechanical property comparison of an A508 Class 3 pressurized water reactor nozzle forging cutout and a 150-mm-thick A533B Class 1 plate are reported. The variation of upper-shelf toughness between the two steels and its orientation sensitivity are discussed on the basis of inclusion and precipitate distributions. Inclusion clusters in A533B, deformed to elongated disks in the rolling plane, have a profound effect on short transverse fracture properties. Data derived using the multi-specimen J-integral method to characterize the initiation of ductile crack extension and resistance to stable crack growth are compared with equivalent Charpy results. Results of the J /SUB R/ -curve analyses indicate (1) that the A533B short transverse crack growth resistance is approximately half that observed from transverse and longitudinal specimen orientations, and (2) that the A508 initiation toughness and resistance to stable crack growth are insensitive to position through the forging wall, and are higher than exhibited by A533B at any orientation in the midthickness position.
- Research Organization:
- National Nuclear Corp. Ltd., Whetstone, Leicester
- OSTI ID:
- 6150072
- Report Number(s):
- CONF-8110313-; TRN: 85-000118
- Journal Information:
- Am. Soc. Test. Mater., Spec. Tech. Publ.; (United States), Vol. STP-803; Conference: Symposium on fracture testing, Philadelphia, PA, USA, 6 Oct 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
STEEL-ASTM-A508
CRACK PROPAGATION
FRACTURE MECHANICS
FRACTURE PROPERTIES
MECHANICAL TESTS
MICROSTRUCTURE
STEEL-ASTM-A533
COMPARATIVE EVALUATIONS
DUCTILITY
PRESSURE VESSELS
ALLOYS
CONTAINERS
CRYSTAL STRUCTURE
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICS
STEELS
TENSILE PROPERTIES
TESTING
220200* - Nuclear Reactor Technology- Components & Accessories
360103 - Metals & Alloys- Mechanical Properties