Influence of Hydrogen Content on Axial Fracture Toughness Parameters of Zr-2.5Nb Pressure Tube Alloy in the Temperature Range of 306-573 K
- Materials Science, Technology and Society, Malmo University, SE20506 (Sweden)
- Department of Mechanical Engineering, Lund Institute of Technology, Lund University, Box 118, SE22100 LUND (Sweden)
Hydrides are suspected to be fracture initiating sites in Zr-alloys and the presence of hydride platelets normal to tensile load significantly influences crack propagation. However, the role of hydrides in crack nucleation and its propagation and influence of temperature on the same has not been delineated clearly. In this work, influence of hydrogen and temperature on the axial fracture toughness parameters of Zr-2.5Nb pressure tube alloys is reported. The fracture toughness tests were carried out using 17 mm width curved compact tension specimens machined from gaseous hydrogen charged tube-sections and tested in the temperature range of 306 to 573 K. Metallography of the samples revealed that hydrides were predominantly oriented along axial-circumferential plane of the tube. The fracture toughness parameters like J{sub Q}, J{sub 0.15}, J{sub Max}, J{sub 1.5}, dJ/da, K{sub JC} and K{sub Max} were determined as per the ASTM standard E-813, with the crack length measured using direct current potential drop technique. The plane strain K values were computed from the corresponding J values. The critical crack length for catastrophic failure was determined using a numerical method, which is widely used in literature. It is observed that for a given test temperature both the fracture toughness parameters representing crack initiation, such as J{sub Q}, J{sub 0.15} and K{sub JC} and crack propagation, such as J{sub Max}, J{sub 1.5}, and K{sub Max}, decrease mildly with increase in hydrogen content whereas mean dJ/da is practically unaffected by hydrogen content. Also, for a given hydrogen content crack initiation fracture toughness parameters showed large scatter with a tendency to decrease with increase in test temperature whereas the crack propagation fracture toughness parameters increased with temperature to a saturation value. (authors)
- Research Organization:
- American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
- OSTI ID:
- 21016447
- Resource Relation:
- Conference: 2006 International congress on advances in nuclear power plants - ICAPP'06, Reno - Nevada (United States), 4-8 Jun 2006; Other Information: Country of input: France; 27 refs; Related Information: In: Proceedings of the 2006 international congress on advances in nuclear power plants - ICAPP'06, 2734 pages.
- Country of Publication:
- United States
- Language:
- English
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