Experimental electro-thermal method for nondestructively testing welds in stainless steel pipes

Conference · Fri Jan 19 04:00:00 EST 1979

OSTI ID:6254937

Green, D. R.

Welds in austenitic stainless steel pipes are notoriously difficult to nondestructively examine using conventional ultrasonic and eddy current methods. Survace irregularities and microscopic variations in magnetic permeability cause false eddy current signal variations. Ultrasonic methods have been developed which use computer processing of the data to overcome some of the problems. Electro-thermal nondestructive testing shows promise for detecting flaws that are difficult to detect using other NDT methods. Results of a project completed to develop and demonstrate the potential of an electro-thermal method for nondestructively testing stainless steel pipe welds are presented. Electro-thermal NDT uses a brief pulse of electrical current injected into the pipe. Defects at any depth within the weld cause small differences in surface electrical current distribution. These cause short-lived transient temperature differences on the pipe's surface that are mapped using an infrared scanning camera. Localized microstructural differences and normal surface roughness in the welds have little effect on the surface temperatures.

• Research Organization: Hanford Engineering Development Lab., Richland, WA (USA)
• DOE Contract Number: EY-76-C-14-2170
• OSTI ID: 6254937
• Report Number(s): HEDL-SA-1705; CONF-790366-1
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420500* -- Engineering-- Materials Testing
ALLOYS
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
DEFECTS
ELECTRICAL TESTING
ELECTROMAGNETIC RADIATION
HEATING
INFRARED RADIATION
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS TESTING
NONDESTRUCTIVE TESTING
PIPES
RADIATIONS
STAINLESS STEELS
STEELS
TESTING
THERMAL TESTING
WELDED JOINTS