Development of Ultrasonic Examination Methods for Austenitic Stainless Steel Weld Inspection

摘要

Signal acquisition and analysis techniques were developed to permit locating notches placed in an austenitic stainless steel pipe weld. Ultrasonic techniques presented here utilized refracted longitudinal and shear inspection beams with a dual element, pitch-catch transducer. Sources of grain noise and the metallurgical iplications of inspecting austenitic stainless steel welds are reviewed. Data were analyzed in both time and frequency domains, and a simple frequency moment algorithm was developed which is sensitive to defect signal and somewhat insensitive to grain noise. Data were also used to train an adaptive learning network (ALN) and the results obtained demonstrate only slight sensitivity to grain noise. (ERA citation 03:035219)