Type, through-wall dimension (depth), and location are the most important flaw characteristics that need to be determined for the fracture-mechanics evaluation of a flawed component or part. In this paper, the three-step approach to the ultrasonic evaluation of flawed reactor pressure vessel components (i.e., flaw detection, identification, and sizing) are discussed in relation to fatigue cracks, slag inclusions, incomplete fusion flaws, and porosity clusters. The emphasis is on flaw identification (cracks vs. benign flaws) which must take place before estimating the depth of the flaw. The composite pulse patterns obtained with four multibeam/multimode SLIC transducers [1] for two model flaws (a side-milled notch and a side-drilled hole) and two real flaws (fatigue crack and slag inclusion) are imaged in a B-scan format.
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