Test of 6-in. -thick pressure vessels: Series 3, Intermediate test vessel V-8A: Tearing behavior of low-upper-shelf material
Tests of several 152-mm-thick vessels were performed to study the behavior of flaws under stress states similar to those in full-scale reactor pressure vessels. The objective of the latest test, V-8A, was to provide accurate quantitative data concerning the growth by ductile tearing and the final ductile tearing instability of a flaw in a low upper-shelf toughness weld located in a cylinder of reactor vessel steel. This test is important because vessels are in service that contain welds that, because of high-copper content, may have their Charpy upper-shelf energy values reduced to relatively low levels by neutron irradiation. Results of the V-8A test are intended to provide an experimental basis for judging the accuracy of vessel fracture safety analysis procedures for low-upper-shelf toughness conditions. The objective of the V-8A test was attained. A tearing instability was observed at a pressure of approx.139 MPa (about two times the design pressure). The flaw, which was initially a fatigue-sharpened notch with an approximately elliptical profile, grew in depth and length to 101.4 and 453 mm, respectively. Pretest and posttest fracture mechanics and stress analyses were made by simplified methods, convenient for investigating a wide range of parameters, and by three-dimensional finite-element methods, which modeled the material properties and geometry more precisely. Ductile flaw growth and instability predictions based upon measured J-resistance and tensile properties were made. Results of analyses based on J/sub R/-controlled crack growth agree reasonably well with experimental observations. 141 refs., 49 figs., 30 tabs.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (USA). Office of Nuclear Regulatory Research; Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5984019
- Report Number(s):
- NUREG/CR-4760; ORNL-6187; ON: DE87014885
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHARPY TEST
CONTAINERS
CRACK PROPAGATION
CRACKS
DESTRUCTIVE TESTING
DUCTILE-BRITTLE TRANSITIONS
FRACTURE MECHANICS
IMPACT TESTS
INSTABILITY
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS TESTING
MECHANICAL TESTS
MECHANICS
PRESSURE VESSELS
REACTOR SAFETY
REACTORS
SAFETY
SEALS
STEELS
STRESS ANALYSIS
TESTING
TRANSDUCERS
VERY HIGH PRESSURE
WATER COOLED REACTORS
WELDED JOINTS