Experimental results of tests to investigate flaw behavior of mechanically loaded stainless steel clad plates
- Oak Ridge National Lab., TN (United States)
A small crack near the inner surface of cold nuclear reactor pressure vessels in an important consideration in the safety assessment of the structural integrity of the vessel. Four-point bend tests on large plate specimens, six clad and two unclad, were performed to determine the effect of stainless steel cladding upon the propagation of small surface cracks subjected to stress states similar to those produced by pressurized thermal shock conditions. Results of tests at temperatures 10 and 60{degrees}C below the nil-ductility transition temperature have shown that a tough surface layer composed of cladding and heat-affected zone has arrested running flaws in clad plates under conditions where unclad plates have ruptured. Furthermore, the load-bearing capacity of clad plates with large subclad flaws significantly exceeded that of an unclad plate with a much smaller flaw. More testing is necessary to unambiguously single out whether it is the cladding or the heat-affected zone that is primarily responsible for the observed enhanced load-bearing capacity of plates. The compressive stresses that limited the depth to which the flaw could propagate are absent in a repressurization event. Nonetheless, the experiments show that if the surface layer is sufficiently tough, it could prevent a flaw, near the surface, from propagating along the surface. The flaw could tunnel below the surface, but a sufficiently tough surface layer would reduce the maximum stress intensity factor.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering; Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10138840
- Report Number(s):
- NUREG/CR-5785; ORNL/TM-11950; ON: TI92012159
- Resource Relation:
- Other Information: PBD: Apr 1992
- Country of Publication:
- United States
- Language:
- English
Similar Records
Observations on the behavior of surface flaws in the presence of cladding
An experimental study of the effect of stainless steel cladding on the structural integrity of flawed steel plates in bending
Related Subjects
36 MATERIALS SCIENCE
PRESSURE VESSELS
MECHANICAL PROPERTIES
CLADDING
CRACKS
CRACK PROPAGATION
FRACTURE MECHANICS
FRACTURE PROPERTIES
THERMAL STRESSES
RADIATION EFFECTS
DEFECTS
WELDING
WELDED JOINTS
EXPERIMENTAL DATA
HEAT TREATMENTS
STAINLESS STEELS
STRESS ANALYSIS
220200
360103
COMPONENTS AND ACCESSORIES