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Title: Use of instrumented charpy tests to determine onset of upper-shelf energy

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 more » 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) « less
Authors: ; ; ;
Publication Date:
OSTI Identifier:4118790
Report Number(s):ORNL--5086
DOE Contract Number:W-7405-ENG-26
Resource Type:Technical Report
Data Type:
Resource Relation:Other Information: Orig. Receipt Date: 30-JUN-76
Research Org:Oak Ridge National Lab., Tenn. (USA)
Country of Publication:United States
Language:English
Subject: N50230* --Metals, 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