0

Full Content is available to subscribers

Subscribe/Learn More  >

Experimental Evaluation of Deformation and Constraint Characteristics in Precracked Charpy and Other Three-Point Bend Specimens

[+] Author Affiliations
Randy K. Nanstad, Donald E. McCabe, Mikhail A. Sokolov, John G. Merkle

Oak Ridge National Laboratory, Oak Ridge, TN

Paper No. PVP2007-26651, pp. 259-267; 9 pages
doi:10.1115/PVP2007-26651
From:
  • ASME 2007 Pressure Vessels and Piping Conference
  • Volume 7: Operations, Applications and Components
  • San Antonio, Texas, USA, July 22–26, 2007
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 0-7918-4285-1 | eISBN: 0-7918-3804-8

abstract

To enable determination of the fracture toughness reference temperature, T0 , with reactor pressure vessel surveillance specimens, the precracked Charpy (PCVN) three-point bend, SE(B), specimen is of interest. Compared with the 25-mm (1 in.) thick compact, 1TC(T), specimen, tests with the PCVN specimen (10×10×55 mm) have resulted in T0 temperatures as much as 40°C lower (a so-called specimen bias effect). The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory developed a two-part project to evaluate the C(T) versus PCVN differences, (1) calibration experiments concentrating on test practices, and (2) a matrix of transition range tests with various specimen geometries and sizes, including 1T SE(B) and 1TC(T). The test material selected was a plate of A533 grade B class 1 steel. The calibration experiments included assessment of the computational validity of J-integral determinations, while the constraint characteristics of various specimen types and sizes were evaluated using key curves and notch strength determinations. The results indicate that J-integral solutions for the small PCVN specimen are comparable in terms of J-integral validity with 1T bend specimens. Regarding constraint evaluations, Phase I deformation is defined where plastic deformation is confined to crack tip plastic zone development, whereas Phase II deformation is defined where plastic hinging deformation develops. In Phase II deformation, the 0.5T SE(B) BxB specimen (slightly larger than the PCVN specimen) consistently showed the highest constraint of all SE(B) specimens evaluated for constraint comparisons. The PCVN specimen begins the Phase II type of deformation at relatively low KR levels, with the result that KJc values above about 70 MPa√m from precracked Charpy specimens are under extensive plastic hinging deformation. For the second part, about twenty specimens of each type and size (65 PCVN) have been tested to enable statistically reliable comparisons of T0 for the various cases, with tests completed at temperatures from −28 to −37°C. The KJc test data obtained for HSST Plates 13B and 13A show PCVN bias values from −30 to −40°C relative to 1TC(T), but the standard 1TSE(B) specimen shows a bias of about −10°C. However, the SE(B) specimens exhibit a tendency for decreasing T0 with decreasing specimen size (B and/or b). The results are compared with those from other materials and observations are noted regarding potential effects of test temperature and metallurgical factors.

Topics: Deformation

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In