Fracture Toughness Characterization of Irradiated Low Upper-Shelf Welds

Hiser, A.L.; Loss, F.J.; Menke, B.H.

doi:10.1520/stp87019850035

Cited by 8 publications

(5 citation statements)

References 1 publication

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“…This conclusion was supported by the experimental observations of Hiser et al [162] and Jablonski [163]. Moreover, Hiser et al first suggested the power-law shape of a J-R curve.…”

Section: Astm E813 E1152 E1737 and E1820 Developmentmentioning

confidence: 58%

Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Zhu

Joyce

2012

Engineering Fracture Mechanics

607

126

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Stress intensity factor Energy release rate CTOD CTOA J-integral J-R curve K-R curve ASTM standard a b s t r a c tThe present paper gives a technical review of fracture toughness testing, evaluation and standardization for metallic materials in terms of the linear elastic fracture mechanics as well as the elastic-plastic fracture mechanics. This includes the early investigations and recent advances of fracture toughness test methods and practices developed by American Society for Testing and Materials (ASTM). The review describes the most important fracture mechanics parameters: the elastic energy release rate G, the stress intensity factor K, the Jintegral, the crack-tip opening displacement (CTOD) and the crack-tip opening angle (CTOA) from the basic concept, definition, to experimental estimation, test methods and ASTM standardizing practices. Attention is paid to guidelines on how to choose an appropriate fracture parameter to characterize fracture toughness for the material of interest, and how to measure the fracture toughness value defined either at a critical point or in a resistance curve format using laboratory specimens. The relevant ASTM fracture toughness test standards considered in this paper are E399 for K Ic testing, E561 for K-R curve testing, E813 for J Ic testing, E1152 for J-R curve testing, E1737 for J Ic and J-R curve testing, E1290 for CTOD (d) testing, a combined common test standard E1820 for measuring the three parameters of K, J and d, E1921 for the transition reference temperature T 0 testing and the master curve of cleavage toughness K Jc testing, and E2472 for CTOA testing. The effects of loading rate, temperature and crack-tip constraint on fracture toughness as well as fracture instability analysis are also reviewed.

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“…This conclusion was supported by the experimental observations of Hiser et al [162] and Jablonski [163]. Moreover, Hiser et al first suggested the power-law shape of a J-R curve.…”

Section: Astm E813 E1152 E1737 and E1820 Developmentmentioning

confidence: 58%

Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Zhu

Joyce

2012

Engineering Fracture Mechanics

607

126

View full text Add to dashboard Cite

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“…17. 15,[38][39][40][41] For wrought austenitic SSs, 3 the J I c values at temperatures up to 550°C are typically >400 kJ/m 2 ; experimental J Ic for Heats L2 and L20 is in the range of 150-230 and 80-120 kJ/m 2 , respectively. The commercial Heats C16 and C19 show the very high fracture toughnesses expected for Type 304 SSs.…”

Section: Nonirradiated Type 304 Stainless Steelmentioning

confidence: 99%

Fracture toughness and crack growth rates of irradiated austenitic stainless steels.

Chopra¹,

Gruber²,

Shack³

2003

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Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of reactor pressure vessels because of their superior fracture toughness properties. However, exposure to high levels of neutron irradiation for extended periods leads to significant reduction in the fracture resistance of these steels. Experimental data are presented on fracture toughness and crack growth rates (CGRs) of austenitic SSs irradiated to fluence levels up to 2.0 x 10 21 n/cm 2 (E > 1 MeV) (ª3.0 dpa) at ª288°C. Crack growth tests were conducted under cycling loading and long hold time trapezoidal loading in simulated boiling water reactor (BWR) environments, and fracture toughness tests were conducted in air. Neutron irradiation at 288°C decreases the fracture toughness of the steels; the data from commercial heats fall within the scatter band for the data obtained at higher temperatures. In addition, the results indicate significant enhancement of CGRs of the irradiated steels in normal water chemistry BWR environment; the CGRs for irradiated steels are a factor of ª5 higher than the disposition curve proposed for sensitized austenitic SSs. The rates decreased by more than an order of magnitude in low-dissolved-oxygen BWR environment.

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“…Their results can be summarized as f & w (1) a data base of J-R curves for irradiated low upper-shelf welds was established for use in elastic-plastic fracture mechanics analyses of reactor pressure vessels; (2) irradiation to 1 x 10'9neutrondcm' (>1 MeV) substantially decreased both the ductile initiation toughness, J, , and tearing modulus; (3) the tearing modulus is a more discriminating indicator of degradation than JG (4) no specimen size effects were observed for irradiated LUS welds; ( 5 ) a correlation was developed between J-R curve parameters and CVN upper-shelf energy which offers potential for use in interpretation of surveillance data from CVN specimens, and (6) the CVN results showed Regulatory Guide 1.99 to be generally conservative for these test reactor irradiations (Hiser et al, 1984), (Hiser et al, 1985), (McGowan, 1985). (Nanstad and Berggren, 1993).…”

Section: Larae Specimensmentioning

confidence: 99%

Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials

Nanstad¹,

Corwin²,

Alexander³

et al. 1995

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The safety of commercial light-water nuclear plants is highly dependent on the structural integrity of the reactor pressure vessel (RPV). In the akmce of radiation damage to the RPV, fracture of the vessel is diffiult to postulate. Exposure to high energy neutrons can result in embrittlement of radiation-sensitive RPV materials. The I-Iea~-Section Steel IrradiationProgram at Oak Ridge National Laboratory, sponsored by the U.S. Nuclear Regulatory Commission (USNRC), is assessing the effects of neutron irradiation on RPV material behavior, especially fracture toughness. The results of these and other studies are used by the USNRC in the evaluation of FWV integrity and regulation of overall nuclear plant safety. In assessing the effects of irradiation, pmtdypic RPV materials are characterized in the unirradiated condition and exposed to radiation under varying conditions. Mechanical property tests are conducted to provide data which can be used in the development of guidelines for structural integrity evaluations, while metallurgical examinations and mechanistic modeling are performed to improve understanding of the mechanisms responsible for embrittlement. The results of these investigations, in conjunction with results from commercial reactor surveillance programs, are used to develop a methodology for the prediction of radiation effects on RPV materials. This irradiation-induced degradation of the materials can be mitigated by thermal annealing, i.e., heating the RPV to a temperature above that of normal operation. Thus, thermal annealing and evaluation of reirradiation behavior are major tasks of the HSSI Program. This paper describes the HSSI Program activities by summarizing some p t and recent results, as well as current and planned studies.

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Fracture Toughness Characterization of Irradiated Low Upper-Shelf Welds

Cited by 8 publications

References 1 publication

Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Fracture toughness and crack growth rates of irradiated austenitic stainless steels.

Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials

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