Use of instrumented charpy tests to determine onset of upper-shelf energy
The Charpy V-notch (C/sub v/) upper-shelf energy is usually defined as that temperature range in which the surface of the C/sub v/ specimen exhibits an appearance indicative of a 100 percent ductile fracture. In an attempt to avoid the need for interpretation, the selection of the C/sub v/ upper-shelf energy is based on the results from an instrumented impact test which provides a permanent record of the load-deflection history of a C/sub v/ specimen during the testing sequence. In the brittle-ductile transition temperature regime, a precipitous drop in the load trace occurs. The amount of the drop decreases at higher temperatures until it is zero, and the zero-drop-in-load temperature is identical to the onset of the C/sub v/ upper shelf. This relationship between the drop in load and energy in an instrumented impact test provides incontestable assurance that the C/sub v/ upper shelf has been obtained. This relationship between drop in load and temperature permits a prediction of the onset of the upper-shelf temperature with as few as two instrumented impact tests. It is also shown that nil-ductility temperature (NDT) (determined by the drop-weight test) is released to the C/sub v/ upper shelf. For the SA-508 Class 2 and SA-533 Grade B Class 1 steels employed in the fabrication of pressure vessels for light-water reactors, C/sub v/ testing at NDT + 180$sup 0$F (100$sup 0$C) will provide upper-shelf energy values. (DLC)
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- W-7405-ENG-26
- NSA Number:
- NSA-33-012609
- OSTI ID:
- 4118790
- Report Number(s):
- ORNL-5086
- Resource Relation:
- Other Information: Orig. Receipt Date: 30-JUN-76
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Ceramics
& Other Materials-Metals & Alloys-Properties
Structure & Phase Studies
N42400 -Engineering-Materials Testing
360103* -Materials-Metals & Alloys-Mechanical Properties
*CHARPY TEST
*STEEL-ASTM-A508- CHARPY TEST
*STEEL-ASTM-A533-B- CHARPY TEST
*STEELS- CHARPY TEST
BRITTLE-DUCTILE TRANSITIONS
ENERGY
FRACTURES
IMPACT TESTS
NOTCHES
PRESSURE VESSELS
TEMPERATURE DEPENDENCE