Detection and depth sizing by ultrasonic images. A procedure for phased array data analysis

An ultrasonic image based data analysis procedure for SCC detection and through wall depth sizing was developed. The developed procedure details wave mode selection, data analysis process and image reading techniques using ultrasonic images collected by phased array ultrasonic examination equipment. The images used for data analysis are cross-sectional view (B-Scope), plan view (C-scope), and end view (D-scope). And the explanations of data analysis techniques are supported by the phased array data taken on a stainless steel pipe weld with laboratory introduced SCC. Followings are findings of data collection and analysis for SCC detection and through wall sizing. (a) Compared with longitudinal wave, shear wave shows higher S/N for SCC detection and it displays base metal to weld metal interface and inner surface of pipe. On the other hand, longitudinal wave collects SCC tip and face echo better than shear wave. As the result, shear wave is suitable for SCC detection and longitudinal wave is suitable for through wall depth sizing. (b) D-scope image displays SCC tip counter and it is helpful for through wall depth sizing. The D-scope of shear wave and longitudinal wave displays SCC tip counter different manner. (author)