Feasibility study of acoustic emission monitoring of pinch welding tritium reservoir fill stems at the Savannah River Site
A study was conducted to determine whether acoustic emission monitoring would be feasible in monitoring the solid-state resistance pinch weld used to seal tritium reservoirs at the Savannah River Site. Experiments were performed using a commercially available acoustic emission detection system, with a transducer mounted on a flat milled onto one of the pinch weld electrodes. Welds were made using a wide range of weld power, from very cold, with no metallurgical bond, to hot, with local fusion and excessive material injection into the tube bore. The tubes were drawn type 316L stainless steel. The welds were confined (anvils prevented material flow outward from the sides of the tube not being forced inward by the electrodes) and all were made using the same electrode force. The total number of ringdown counts for each weld was more correlated with weld power and bond length than total energy counts or total number of hits. The onset of large acoustic emission at higher weld power coincides with the injection of material into the tube bore, termed extrusion if arising from a solid state weld or spitting if arising from a weld with local fusion. Since large extrusions and spits, identified by radiography, cause rejection of production welds, a useful function of acoustic emission monitoring of pinch welding might be to detect the onset of extrusion or spitting. The low level of acoustic emission at production weld power levels (and below), the variability of acoustic emission at power levels causing extrusion and spitting, and the inability of acoustic emission to distinguish welds made with oxidized stems indicates that acoustic emission monitoring would not be a useful nondestructive evaluation of reservoir pinch welding at the Savannah River Site. 3 refs., 3 figs.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (USA)
- Sponsoring Organization:
- DOE/DP
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 6080017
- Report Number(s):
- WSRC-MS-90-297; CONF-9011174--2; ON: DE91007210
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
420500* -- Engineering-- Materials Testing
ACOUSTIC EMISSION TESTING
ACOUSTIC MONITORING
ACOUSTIC TESTING
ALLOYS
AUSTENITIC STEELS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CHROMIUM-NICKEL-MOLYBDENUM STEELS
CORROSION RESISTANT ALLOYS
FEASIBILITY STUDIES
HEAT RES
HIGH ALLOY STEELS
HYDROGEN ISOTOPES
IRON ALLOYS
IRON BASE ALLOYS
ISOTOPES
JOINTS
LIGHT NUCLEI
MATERIALS TESTING
MOLYBDENUM ALLOYS
MONITORING
NATIONAL ORGANIZATIONS
NICKEL ALLOYS
NONDESTRUCTIVE TESTING
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
SAVANNAH RIVER PLANT
SEALS
STAINLESS STEEL-316L
STAINLESS STEELS
STEEL-CR17NI12MO3-L
STEELS
TESTING
TRITIUM
US AEC
US DOE
US ERDA
US ORGANIZATIONS
WELDED JOINTS
YEARS LIVING RADIOISOTOPES